@article{montaser_zaghloul_kelley_2024, title={Effects of tri-solvent and electrospinning condition on the morphology of cellulose acetate nanofibers}, volume={67}, ISSN={["2357-0245"]}, DOI={10.21608/EJCHEM.2023.200584.7742}, number={3}, journal={EGYPTIAN JOURNAL OF CHEMISTRY}, author={Montaser, Ahmed Saad and Zaghloul, Saad and Kelley, Stephen}, year={2024}, month={Mar}, pages={25–30} }
 @article{forfora_azuaje_vivas_vera_brito_venditti_kelley_tu_woodley_gonzalez_2024, title={Evaluating biomass sustainability: Why below-ground carbon sequestration matters}, volume={439}, ISSN={["1879-1786"]}, url={https://doi.org/10.1016/j.jclepro.2024.140677}, DOI={10.1016/j.jclepro.2024.140677}, abstractNote={Biomass, as a raw material, has been identified as a crucial component of decarbonization strategies to mitigate climate change. Decisions on which biomass should be targeted for different purposes are dependent on variables such as availability, chemical composition, and sustainability. Consumer perception often positions non-wood sources, such as bamboo, as environmentally preferable feedstocks for fiber-based product production. Yet, this perceived environmental benefit lacks robust scientific substantiation and standardized methodologies. This study addresses this gap by conducting a cradle-to-gate life cycle assessment (LCA) of twelve biomass production systems encompassing tree plantations, dedicated crops, and agricultural residues for energy and bioproducts manufacture. The evaluated feedstocks include southern softwood, wheat straw, rice straw, rice husk, hemp hurd, sugarcane bagasse, switchgrass, biomass sorghum (United States), eucalyptus (Brazil), bamboo (China), and northern softwood (Canada). Incorporating a critical yet often overlooked factor, this LCA integrates the potential soil organic carbon sequestration (SOC) via below-ground biomass for each biomass type. This consideration significantly alters the estimated carbon intensity per ton of feedstock, potentially reshaping sustainability perceptions as certain systems emerge as carbon sinks. From a cradle-to-farm gate perspective, the assessed global warming potential for biomass production spans 12–245 kg CO2eq per oven-dry ton (ODt), factoring only anthropogenic emissions. However, when accounting for SOC sequestration, the range shifts to −170 to 228 kg CO2eq per ODt, highlighting the potential role of biomass to act as carbon sink systems. By illuminating the dynamic influence of SOC sequestration, this study contributes to a more comprehensive understanding of biomass-related carbon emissions, shedding light on pathways to mitigate environmental impact.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Forfora, Naycari and Azuaje, Ivana and Vivas, Keren A. and Vera, Ramon E. and Brito, Amelys and Venditti, Richard and Kelley, Stephen and Tu, Qingshi and Woodley, Alex and Gonzalez, Ronalds}, year={2024}, month={Feb} }
 @article{park_yoo_cho_park_cruz_kelley_park_2024, title={Exploring potential of cellulose acetate sulfate films for sustainable packaging: tuning characteristics via sulfate group variation}, volume={1}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-023-05713-8}, journal={CELLULOSE}, author={Park, Seonghyun and Yoo, Seunghyun and Cho, Seong-Min and Park, Hyeonji and Cruz, David and Kelley, Stephen S. and Park, Sunkyu}, year={2024}, month={Jan} }
 @article{dey_worfolk_lower_sagues_nimlos_kelley_park_2024, title={Phenolic Resin Derived Hard Carbon Anode for Sodium-Ion Batteries: A Review}, volume={5}, ISSN={["2380-8195"]}, url={https://doi.org/10.1021/acsenergylett.4c00688}, DOI={10.1021/acsenergylett.4c00688}, abstractNote={Sodium-ion batteries are complementary to lithium-ion batteries for grid-scale energy storage applications due to lower cost, safety, and potential for sustainable supply chains. The past decade has witnessed enormous research efforts in developing hard carbon anode materials for sodium-ion batteries. Phenolic resins have received significant attention as hard carbon precursors due to their high carbon yield, highly cross-linked structure, low cost, mature technology, and excellent electrochemical performance of corresponding hard carbon anode. This Review exclusively highlights the state-of-the-art preparation of hard carbon from phenolic resins, and the electrochemical performance in sodium-ion batteries. Cross-linked resins are prepared from three phenolic monomers (phenol, resorcinol, and phloroglucinol) to produce hard carbon. The effects of carbonization temperature on the microstructure, and electrochemical properties of hard carbon have been summarized here. Hard carbon formation, and sodium storage mechanisms have been briefly outlined. Finally, this Review provides an industrial perspective on hard carbon production at scale.}, journal={ACS ENERGY LETTERS}, author={Dey, Shaikat Chandra and Worfolk, Brian and Lower, Lillian and Sagues, William Joe and Nimlos, Mark R. and Kelley, Stephen S. and Park, Sunkyu}, year={2024}, month={May} }
 @article{park_rahmani_treasure_lee_tiller_pasquinelli_kelley_park_2024, title={Understanding the formation of insoluble gel particles during cellulose diacetate production}, volume={2}, ISSN={["1572-882X"]}, url={http://dx.doi.org/10.1007/s10570-024-05769-0}, DOI={10.1007/s10570-024-05769-0}, journal={CELLULOSE}, author={Park, Seonghyun and Rahmani, Farzin and Treasure, Trevor and Lee, Joo and Tiller, Phoenix and Pasquinelli, Melissa A. and Kelley, Stephen S. and Park, Sunkyu}, year={2024}, month={Feb} }
 @article{molina_park_park_kelley_2023, title={Effective toluene removal from aqueous solutions using fast pyrolysis-derived activated carbon from agricultural and forest residues: Isotherms and kinetics study}, volume={9}, ISSN={["2405-8440"]}, url={https://doi.org/10.1016/j.heliyon.2023.e15765}, DOI={10.1016/j.heliyon.2023.e15765}, abstractNote={In this study, the production and characterization of activated carbons (ACs) from agricultural and forest residue using physical activation are discussed. Biomass-based biochars produced during fast pyrolysis process is introduced as alternative precursors to produce AC and the integrated process for the co-production of porous adsorbent materials from biochar via the fast pyrolysis process is suggested. Moderate surface areas and good adsorption capacities were obtained from switchgrass (SWG) and pine tops (PT) based AC. The surface areas were 959 and 714 m2/g for SWG- and PT-based AC, respectively. The adsorption capacities using toluene as pollutant for two model systems of 180 and 300 ppm were measured and ranged between 441-711 and 432-716 mg/g for SWG-based and PT-based AC, respectively. The nitrogen adsorptive behavior, Lagergren pseudo-second-order kinetic (PSOK) model and kinetics isotherms studies describe a heterogeneous porous system, including a mesoporous fraction with the existence of a multilayer adsorption performance. The presence of micropores and mesopores in SWG- and PT-based AC suggests potential commercial applications for using pyrolytic biochars for AC production.}, number={5}, journal={HELIYON}, author={Molina, Eliezer A. Reyes and Park, Seonghyun and Park, Sunkyu and Kelley, Stephen S.}, year={2023}, month={May} }
 @article{brito_suarez_pifano_reisinger_wright_saloni_kelley_gonzalez_venditti_jameel_2023, title={Environmental Life Cycle Assessment of Premium and Ultra Hygiene Tissue Products in the United States}, volume={18}, ISSN={["1930-2126"]}, DOI={10.15376/biores.18.2.4006-4031}, abstractNote={Under the controversial concern of using virgin fibers in hygiene tissue products, mostly Bleached Eucalyptus Kraft (BEK) and Northern Bleached Softwood Kraft (NBSK), consumers are responding by purchasing self-labeled sustainable products. As of today, there are no established sustainability reported results to inform consumers about the carbon footprint of hygiene tissue. To fill this gap, this study used Life Cycle Assessment to evaluate the environmental impacts across the supply chain (cradle to gate) to produce Premium and Ultra grades of bath tissue, including the production of feedstock, pulp production, and tissue production stages, with focus on Global Warming Potential (GWP). The results showed that one air-dried metric ton (ADmt) of BEK pulp had an associated GWP of 388 kgCO2eq, whereas one ADmt of NBSK pulp presented values ranging between 448 and 596 kgCO2eq, depending on the emissions allocation methodology used. It was estimated that the GWP of one finished metric ton of tissue weighted average could range from 1,392 to 3,075 kgCO2eq depending on mill location, electricity source, and machine technology. These results provide an understanding of the factors affecting the environmental impact of hygiene tissue products, which could guide manufacturers and consumers on decisions that impact their carbon footprint.}, number={2}, journal={BIORESOURCES}, author={Brito, Amelys and Suarez, Antonio and Pifano, Alonzo and Reisinger, Lee and Wright, Jeff and Saloni, Daniel and Kelley, Stephen and Gonzalez, Ronalds and Venditti, Richard and Jameel, Hasan}, year={2023}, month={May}, pages={4006–4031} }
 @article{molina_vook_sagues_kim_labbe_park_kelley_2023, title={Green Needle Coke Production from Pyrolysis Biocrude toward Bio-based Anode Material Manufacture: Biochar Fines Addition Effect as ?Physical Template? on the Crystalline Order}, volume={11}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.2c06952}, DOI={10.1021/acssuschemeng.2c06952}, abstractNote={A new method for producing green needle coke (GNC) is developed by replacing the "heavy fraction" of petroleum pitch delayed coking with fast pyrolysis biocrude. A series of alternative biocrude distillation, carbonization, and calcination conditions were investigated to determine the influence of these processing parameters onto the crystalline structure of the resulting graphitized material. For the first time, the addition of biochar fines was found to serve as a "physical template" to increase the graphitic nature of the final product. During the initial biocrude carbonization (350–450 °C), volatile compounds are released, and aromatics in pyrolysis biocrude experience condensation, resulting in GNC solids with carbon contents above 95 wt % and some early lamellar structure. In the second stage of the thermal process (25–1500 °C), there are additional thermal decomposition reactions with an increase in the aromatic nature of the graphitized solid. It was found that systematic addition of biochar fines induces a nucleating effect during the GNC development. Thermogravimetric analysis suggests that biochar fines promote polycondensation reactions by modifying the biopitch structure and molecular weight, while elemental analysis (CHN) shows a reduction in both H/C and O/C ratios which are consistent with the increase in aromaticity and removal of oxygenated compounds as thermal treatment evolves. The effects of different bio-based pitch materials (after distillation) and GNC intermediates were evaluated by pyrolysis-gas chromatography mass spectrometry and Fourier transform infrared, displaying slight changes on product yields and quality. X-ray diffraction patterns taken after graphitization evidence an increase in the graphitic order with the addition of biochar fines. Transmittance electron microscopy depicts an improvement on graphitic morphology as biochar fine content increases. The use of biochar fines showed a significant increase in graphitic ordering at addition levels above 0.01 wt %. These results show that thermally treated biocrude/biochar fine systems can produce graphitic structures (hard carbon-like) that might be suitable for the manufacture of sodium-ion batteries.}, number={18}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Molina, Eliezer A. Reyes and Vook, Trevor and Sagues, William J. and Kim, Keonhee and Labbe, Nicole and Park, Sunkyu and Kelley, Stephen S.}, year={2023}, month={May}, pages={6944–6955} }
 @article{park_yoo_cho_kelley_park_2023, title={Production of single-component cellulose-based hydrogel and its utilization as adsorbent for aqueous contaminants}, volume={243}, ISSN={["1879-0003"]}, DOI={10.1016/j.ijbiomac.2023.125085}, abstractNote={The growing concern for the environment has resulted in renewed interest in bio-based resources. This study aims to produce a hydrogel adsorbent from cellulose and examine its adsorption performance. In pursuit of this goal, we report a simple one-pot synthesis of cellulose acetate sulfate (CAS), followed by the formation of CAS hydrogels and their subsequent adsorption performances. The CAS includes both hydrophilic and hydrophobic functional groups, enable the formation of a single-component hydrogel through intermolecular interactions in deionized water. The thermal reversibility of CAS hydrogels makes them easily processable into various shapes. The durability of the CAS hydrogel adsorbents can be improved by introducing divalent cations (e.g., Ca2+), which create ionically crosslinked hydrogels. The ionically a crosslinked CAS hydrogel adsorbent exhibits a maximum adsorption capacity of 245 mg/g for methylene blue (MB) at 23 °C and a pH of 7. The adsorption behavior of MB on the CAS hydrogel follows both the pseudo-second-order model and the Langmuir adsorption isotherm model. Furthermore, the CAS hydrogel adsorbent maintains a 70 % removal ratio after five cycles. The simplicity of synthesis and hydrogel formation opens up new possibilities for producing and utilizing cellulose-based hydrogels as adsorbents for aqueous contaminants.}, journal={INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES}, author={Park, Seonghyun and Yoo, Seunghyun and Cho, Seong-Min and Kelley, Stephen S. and Park, Sunkyu}, year={2023}, month={Jul} }
 @article{molina_soneja_diaz_tilotta_kelley_2022, title={At-Line Sampling and Characterization of Pyrolytic Vapors from Biomass Feedstock Blends Using SPME-GC/MS-PCA: Influence of Char on Fast Pyrolysis}, volume={12}, ISSN={["1520-5118"]}, DOI={10.1021/acs.jafc.2c06043}, abstractNote={Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) analysis was used for the at-line sampling of pyrolytic vapors produced during the fast pyrolysis of biomass. The pure and binary blends of switchgrass (SWG) and pine harvest residues (PT6) were used as biomass feedstocks. Sequential SPME sampling allowed for monitoring of changes in the pyrolysis vapors as char accumulated in the fluid bed. The relative concentration and composition of the pyrolysis vapors desorbed from the SPME fibers were investigated using GC-MS, and the resulting chromatograms were analyzed using principal component analysis (PCA) to compare the composition of the pyrolysis vapors over the course of the pyrolysis run. The chemical compositions of both carbohydrate and lignin fragments varied as the char builds up in the reactor bed. Fragments derived from cellulose and hemicelluloses included anhydrosugars, furans, and light-oxygenated compounds. Lignin fragments included methoxyphenols, phenolic ketones, aldehydes, and low-molecular-weight aromatics. The composition of the carbohydrate fragments changed more than those of the lignin fragments as the char built up in the fluid bed. This combination of SPME-GC/MS-PCA was a novel, easy, and effective method for measuring the composition and changes in the composition of pyrolysis vapors during the fast pyrolysis process. This work also highlighted the effect of char build-up on the composition of the overall pyrolysis vapors.}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Molina, Eliezer A. Reyes and Soneja, Ravi and Diaz, Maria Herrera and Tilotta, David C. and Kelley, Stephen S.}, year={2022}, month={Dec} }
 @article{trovagunta_kelley_lavoine_2022, title={Dual-Templating Approach for Engineering Strong, Biodegradable Lignin-Based Foams}, volume={11}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.2c04056}, DOI={10.1021/acssuschemeng.2c04056}, abstractNote={Technical lignins are generated as byproducts from the wood pulping industry. Although their estimated annual production amounts to approximately 70 million tons, their exploitation as value-added products remains insignificant. Yet, the diversity in the molecular structure and surface chemistry of technical lignins and their intrinsic role as mechanical support of plants may be an asset to consider in the engineering of plant-inspired materials such as biofoams. Valorization of lignins into solid foams, however, rarely accounts for more than 45–50 wt % of lignins because of their brittle nature. Herein, we report a strategy to develop fully biodegradable lignin-based foams of high stiffness, strength, and toughness that are comparable to, or in some cases exceed, the performance of petroleum-derived foams. A dual-templating approach using ice and cellulose nanofibrils (CNFs) as templates was selected to control the porous architecture of the foams made by the assembly of lignin and cellulose in the cell walls. Foams with varying lignin-to-CNF weight ratios showed enhanced structural and mechanical integrity compared with neat lignin and CNF foams. For 80–90 wt % of lignin, a significant increase (+50%) in the foams’ compressive performance was observed. Varying the degree of sulfonation of lignin and in turn its chemical interaction with cellulose enabled the generation of biodegradable composite foams with tunable compressive strength. The greater the colloidal stability of the lignin-CNF suspension, the higher the foams’ compressive performance. This study thus discusses an engineering approach for the valorization of technical lignins into sustainable foams that have potential as packaging materials and sandwich panels, in which high stiffness, strength, and toughness per unit weight are required.}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Trovagunta, Ramakrishna and Kelley, Stephen S. and Lavoine, Nathalie}, year={2022}, month={Nov} }
 @article{diaz_scouse_kelley_2022, title={Environmental full cost accounting of alternative materials used for railroad ties: Treated-wood and concrete case study}, volume={364}, ISSN={["1879-1786"]}, DOI={10.1016/j.jclepro.2022.132536}, abstractNote={Environmental full-cost accounting (FCA) is a novel analytical framework that describes ecological and human health impacts of products and processes using financial measures. These impacts are generally considered to be external to the cost of the product, and are not traditionally reflected in the sales price of the product or service. FCA methodology provides a novel framework to analyze product alternatives from an inclusive perspective considering economic, societal, and environmental impacts. In this work, researchers use the FCA methodology to compare a series of chemically treated wooden and concrete railroad crossties. For all products analyzed in the study, production of the treatment chemicals and the crosstie, use, and disposal stages were included along with mass of emissions, and associated health and environment costs. This FCA allows for a comparison of alternatives products and insight into the implications of final disposal. Two alternative end of life (EOL) scenarios were explored, e.g., energy recovery where the chemically treated wood is burned for energy production, and disposal in a landfill. This work shows that the EOL scenario for treated crossties play a dominate role when defining environmental and social costs. This contrasts with concrete crossties, where the production stage is the main contributor. Wood treatment utilizing copper-chrome-arsenic (CCA) represents a worst case EOL scenario due to high costs associated with atmospheric emissions of arsenic and CO2. Finally, depending on how biogenic CO2 is treated, concrete or furfuryl alcohol treated wood had the lowest environmental price.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Diaz, Maria A. Herrera and Scouse, Adam and Kelley, Stephen S.}, year={2022}, month={Sep} }
 @article{alanya-rosenbaum_bergman_wiedenbeck_hubbard_kelley_2022, title={Life cycle assessment of utilizing freshly cut urban wood: A case study}, volume={76}, ISSN={["1610-8167"]}, DOI={10.1016/j.ufug.2022.127723}, abstractNote={Large amounts of urban wood resources are generated through tree removals in urban areas. Therefore, there is a growing interest to improve the environmental performance of the urban wood supply chain by quantifying the environmental impacts of creating high-value products from urban tree removals to enhance its utilization. By surveying existing urban wood utilization operations for primary data in two major cities: Baltimore, Maryland, and Milwaukee, Wisconsin, a new life cycle inventory (LCI) dataset per m 3 of dry urban hardwood lumber and live edge slabs was created. Incorporating the new LCI data into life cycle assessment method, the total global warming (GW) impact of converting urban trees to kiln-dried lumber was estimated to be 122 kg CO 2 eq and 336 kg CO 2 eq per m 3 of lumber produced for Baltimore and Milwaukee, respectively. In both cases, the total environmental impact of the product was dominated by the conversion of urban trees to kiln dried lumber at the sawmill processing stage . Using scenario analysis for the source of heat generation used in kiln (force) drying wood, substituting wood fuel from coproducts for natural gas in a boiler for Milwaukee resulted in a substantial reduction in fossil-derived GW impact. Urban and traditional hardwood lumber production follow similar GW impact trajectories over their life-cycle stages with the lumber processing stage having the highest environmental impacts for both. Increasing the overall lumber yield and decreasing kiln (force) drying would substantially improve the environmental performance of urban hardwood lumber and help make it comparable to traditional lumber.}, journal={URBAN FORESTRY & URBAN GREENING}, author={Alanya-Rosenbaum, S. and Bergman, R. D. and Wiedenbeck, J. and Hubbard, S. S. and Kelley, S. S.}, year={2022}, month={Oct} }
 @article{suarez_ford_venditti_kelley_saloni_gonzalez_2022, title={Rethinking the use of bio-based plastics to accelerate the decarbonization of our society}, volume={186}, ISSN={0921-3449}, url={http://dx.doi.org/10.1016/j.resconrec.2022.106593}, DOI={10.1016/j.resconrec.2022.106593}, abstractNote={The need to tackle the current environmental impact of plastics is driving the development of new bio-based materials. Although these bioplastics offer carbon footprint reductions, their role in a more sustainable economy is still unclear. Herein, a systematic review was performed to understand the impact of producing bioplastics. This information was used to perform a life cycle assessment considering different end-of-life scenarios. Then a Smart Use of Materials based on the assumption of only using certain materials in targeted applications was proposed. It was found that the dedicated use of bio-polyethylene terephthalate for packaging and polylactic acid for textiles can offer a carbon footprint reduction of up to 67% and 80% respectively. Therefore, we present a major opportunity to decarbonize our society using current technologies and supply chains. This concept contributes to building a society that understands the place of bio-based materials and addresses pollution from a material selection perspective.}, journal={Resources, Conservation and Recycling}, publisher={Elsevier BV}, author={Suarez, Antonio and Ford, Ericka and Venditti, Richard and Kelley, Stephen and Saloni, Daniel and Gonzalez, Ronalds}, year={2022}, month={Nov}, pages={106593} }
 @article{kim_sriram_fang_kelley_park_2021, title={An eco-friendly approach for blending of fast-pyrolysis bio-oil in petroleum-derived fuel by controlling ash content of loblolly pine}, volume={179}, ISSN={["1879-0682"]}, DOI={10.1016/j.renene.2021.08.033}, abstractNote={This paper describes the effect of the ash content in biomass on the distribution of pyrolysis products and the miscibility of bio-oil in diesel. Ash content of loblolly pine wood (0.5 wt %, 1.1 wt %, and 1.5 wt %) was systematically varied by impregnating the wood with potassium carbonate solution. Variation in the ash content did not create a significant change in the chemical composition of the impregnated biomass. However, the response to a variety of thermal treatments changed significantly. The volatile matter content decreased from 88.3% to 78.2%, while the bio-oil yield declined from 45.7% to 29.9% as the ash content increased. Although the total organic yield decreased with increased biomass ash content, the total concentration of phenolic monomers increased from 2.8 mg/g to 20.2 mg/g, and bio-oil miscibility with a commercial diesel fuel increased from 6.7% to 13.4% based on wet bio-oil. The miscibility of guaiacol and 4-methyl guaiacol in diesel was higher than that of catechol, due to the lower polar and hydrogen bonding contribution. Test in a diesel engine showed a simultaneous reduction of HC and NOx emissions using diesel extracts.}, journal={RENEWABLE ENERGY}, author={Kim, Hoyong and Sriram, Subash and Fang, Tiegang and Kelley, Stephen and Park, Sunkyu}, year={2021}, month={Dec}, pages={2063–2070} }
 @article{lan_ou_park_kelley_nepal_kwon_cai_yao_2021, title={Dynamic life-cycle carbon analysis for fast pyrolysis biofuel produced from pine residues: implications of carbon temporal effects}, volume={14}, ISSN={["1754-6834"]}, url={https://doi.org/10.1186/s13068-021-02027-4}, DOI={10.1186/s13068-021-02027-4}, abstractNote={Abstract}, number={1}, journal={BIOTECHNOLOGY FOR BIOFUELS}, publisher={Springer Science and Business Media LLC}, author={Lan, Kai and Ou, Longwen and Park, Sunkyu and Kelley, Stephen S. and Nepal, Prakash and Kwon, Hoyoung and Cai, Hao and Yao, Yuan}, year={2021}, month={Sep} }
 @article{trovagunta_kelley_lavoine_2021, title={Highlights on the mechanical pre-refining step in the production of wood cellulose nanofibrils}, volume={10}, ISSN={["1572-882X"]}, url={https://doi.org/10.1007/s10570-021-04226-6}, DOI={10.1007/s10570-021-04226-6}, number={18}, journal={CELLULOSE}, publisher={Springer Science and Business Media LLC}, author={Trovagunta, Ramakrishna and Kelley, Stephen S. and Lavoine, Nathalie}, year={2021}, month={Oct} }
 @article{lan_ou_park_kelley_english_yu_larson_yao_2021, title={Techno-Economic Analysis of decentralized preprocessing systems for fast pyrolysis biorefineries with blended feedstocks in the southeastern United States}, volume={143}, ISSN={["1879-0690"]}, url={https://doi.org/10.1016/j.rser.2021.110881}, DOI={10.1016/j.rser.2021.110881}, abstractNote={This study evaluated the economic feasibility of fast pyrolysis biorefineries fed with blended pine residues and switchgrass in the Southeastern U.S. with different supply chain design. Previous techno-economic analyses (TEA) have focused on either blended biomass or decentralized preprocessing without investigating the impacts of varied process parameters, technology options, and real-world biomass distribution. This study fills the literature gap by modeling scenarios for different biomass blending ratios, biorefinery and preprocessing site (so-called depot) capacities, and alternative preprocessing technologies. High-resolution, real-world geospatial data were analyzed using Geographic Information Systems to facilitate supply chain design and TEA. For a decentralized system, the minimum fuel selling price (MFSP) of biofuel was $3.92–$4.33 per gallon gasoline equivalent (GGE), while the MFSP for the centralized biorefinery at the same capacities ranged between $3.75–$4.02/GGE. Implementing a high moisture pelleting process depot rather than a conventional pelleting process lowered the MFSP by $0.03–$0.17/GGE. Scenario analysis indicated decreased MFSP with increasing biorefinery capacities but not necessarily with increasing depot size. Medium-size depots (500 OMDT/day) achieved the lowest MFSP. This analysis identified the optimal blending ratios for two preprocessing technologies at varied depot sizes. Counterintuitively, increasing the proportion of higher cost switchgrass reduced the MFSP for large biorefineries (>5000 ODMT/day), but increased the MFSP for small biorefineries (1000–2500 ODMT/day). Although the decentralized systems have a higher MFSP based on current analysis, it has other potential benefits such as mitigated supply chain risks and improved feedstock quality that are difficult to be quantified in this TEA.}, journal={RENEWABLE & SUSTAINABLE ENERGY REVIEWS}, publisher={Elsevier BV}, author={Lan, Kai and Ou, Longwen and Park, Sunkyu and Kelley, Stephen S. and English, Burton C. and Yu, T. Edward and Larson, James and Yao, Yuan}, year={2021}, month={Jun} }
 @article{lan_xu_kim_ham_kelley_park_2021, title={Techno-economic analysis of producing xylo-oligosaccharides and cellulose microfibers from lignocellulosic biomass}, volume={340}, ISSN={["1873-2976"]}, url={http://dx.doi.org/10.1016/j.biortech.2021.125726}, DOI={10.1016/j.biortech.2021.125726}, abstractNote={This study assesses the economic performance of a biorefinery producing xylo-oligosaccharides (XOS) from miscanthus by autohydrolysis and purification based on a rigorous model developed in ASPEN Plus. Varied biorefinery capacities (50–250 oven dry metric ton (ODMT)/day) and three XOS content levels (80%, 90%, 95%) are analyzed. The XOS minimum selling price (XOS MSP) is varied between $3,430–$7,500, $4,030–$8,970, and $4,840–$10,640 per metric ton (MT) for 80%, 90%, and 95% content, respectively. The results show that increasing biorefinery capacity can significantly reduce the XOS MSP and higher purity leads to higher XOS MSP due to less yield, and higher capital and operating costs. This study also explores another system configuration to produce high-value byproducts, cellulose microfiber, by utilizing the cellulose to produce microfiber instead of combusting for energy recovery. The XOS MSP of cellulose microfiber case is $2,460–$7,040/MT and thus exhibits potential economic benefits over the other cases.}, journal={BIORESOURCE TECHNOLOGY}, publisher={Elsevier BV}, author={Lan, Kai and Xu, Yiling and Kim, Hoyong and Ham, Choonghyun and Kelley, Stephen S. and Park, Sunkyu}, year={2021}, month={Nov} }
 @article{ou_dou_yu_kim_park_lee_kelley_park_2021, title={Techno-economic analysis of sugar production from lignocellulosic biomass with utilization of hemicellulose and lignin for high-value co-products}, volume={15}, ISSN={["1932-1031"]}, DOI={10.1002/bbb.2170}, abstractNote={Abstract}, number={2}, journal={BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR}, author={Ou, Longwen and Dou, Chang and Yu, Ju-Hyun and Kim, Hoyong and Park, Yong-Cheol and Lee, Eun Yeol and Kelley, Stephen and Park, Sunkyu}, year={2021}, month={Mar}, pages={404–415} }
 @article{liang_gu_bergman_kelley_2020, title={COMPARATIVE LIFE-CYCLE ASSESSMENT OF A MASS TIMBER BUILDING AND CONCRETE ALTERNATIVE}, volume={52}, ISSN={["0735-6161"]}, DOI={10.22382/wfs-2020-019}, abstractNote={The US housing construction market consumes vast amounts of resources, with most structural elements derived from wood, a renewable and sustainable resource. The same cannot be said for all nonresidential or high-rise buildings, which are primarily made of concrete and steel. As part of continuous environmental improvement processes, building life-cycle assessment (LCA) is a useful tool to compare the environmental footprint of building structures. This study is a comparative LCA of an 8360-m 2 , 12-story mixed-us apartment/office building designed for Portland, OR, and constructed from mainly mass timber. The designed mass timber building had a relatively lightweight structural frame that used 1782 m 3  of cross-laminated timber (CLT) and 557 m 3  of glue-laminated timber (glulam) and associated materials, which replaced approximately 58% of concrete and 72% of rebar that would have been use in a conventional building. Compared with a similar concrete building, the mass timber building had 18%, 1% and 47% reduction in the impact categories of global warming, ozone depletion, and eutrophication, respectively, for the A1-A5 building LCA. The use of CLT and glulam materials substantially decreased the carbon footprint of the building, although it consumed more primary energy compared with a similar concrete building. The impacts for the mass timber building were affected by large amounts of gypsum board, which accounted for 16% of the total building mass. Both lowering the amount of gypsum and keeping the mass timber production close to the construction site could lower the overall environmental footprint of the mass timber building.}, number={2}, journal={WOOD AND FIBER SCIENCE}, author={Liang, Shaobo and Gu, Hongmei and Bergman, Richard and Kelley, Stephen S.}, year={2020}, month={Apr}, pages={217–229} }
 @article{scouse_kelley_venditti_mcconnell_2020, title={Evaluating Sustainable Product Alternatives by Combining Life Cycle Assessment with Full-cost Accounting: A Highway Guardrail Case Study}, volume={15}, ISSN={["1930-2126"]}, DOI={10.15376/biores.15.4.9103-9127}, abstractNote={Full-cost accounting techniques incorporate the environmental and societal burdens a product generates through its manufacture, use, and disposal into that product’s price. This research generates full-cost prices for functionally equivalent chromated copper arsenate (CCA) treated wood and galvanized steel guardrail posts by combining previously conducted life cycle inventory analyses results with secondary emission valuation data. Based on the analysis, both CCA-treated posts and galvanized steel posts have environmental damage costs associated with emissions generated through the product’s manufacturing, use, and disposal stages. After developing full-cost prices for product alternatives, CCA-treated wood guardrail posts were found to be a more economical and environmentally responsible alternative to galvanized steel. In addition to generating full-cost prices, this research uses Monte Carlo simulation to provide estimates of variability around CCA-treated wood and galvanized steel damage costs.}, number={4}, journal={BIORESOURCES}, author={Scouse, Adam A. and Kelley, Steven S. and Venditti, Richard A. and McConnell, T. Eric}, year={2020}, month={Nov}, pages={9103–9127} }
 @article{edmunds_peralta_sharma-shivappa_kelley_chiang_miller_giles_sykes_deoppke_gjersing_et al._2020, title={Fungal Pretreatment and Enzymatic Hydrolysis of Genetically-modified Populus trichocarpa}, volume={15}, ISSN={["1930-2126"]}, DOI={10.15376/biores.15.3.6488-6505}, abstractNote={Fungal pretreatment of Populus trichocarpa wood genetically modified to reduce lignin and alter lignin chemistry is investigated for its effectiveness as an alternative to common pretreatment methods. The goal of this work is to improve biomass utilization for biofuel and biochemical applications by increasing sugar release. Sugar release after enzymatic hydrolysis was measured after various biomass pretreatments (including wood-rot fungus, hot water, and dilute acid). In the wildtype, and in constructs downregulated in PAL, 4CL, and C3H, the fungal pretreatment resulted in substantial improvements in sugar yields, up to 2.4-fold increase in glucose yield and 6-fold increase in xylose yield after enzymatic hydrolysis compared to the unpretreated control. However, the effects of fungal pretreatment were inconsistent, and in genetic lines down-regulated in 4CL, CCoAOMT, CAld5H, and C3H, fungal pretreatment yielded similar or decreased sugar release after enzymatic hydrolysis.}, number={3}, journal={BIORESOURCES}, author={Edmunds, Charles W. and Peralta, Perry and Sharma-Shivappa, Ratna R. and Kelley, Stephen S. and Chiang, Vincent L. and Miller, Zachary D. and Giles, Richard L. and Sykes, Robert W. and Deoppke, Crissa and Gjersing, Erica and et al.}, year={2020}, month={Aug}, pages={6488–6505} }
 @article{rice_schoen_aristidou_burgess_capalbo_czarnecki-maulden_dunham_ejeta_famigilietti_gould_et al._2020, title={Keeping up with the fast-moving world of crisis management}, volume={37}, ISSN={["1572-8366"]}, DOI={10.1007/s10460-020-10045-5}, abstractNote={Author(s): Rice, Charles W; Schoen, Robin; Aristidou, Aristos; Burgess, Shane C; Capalbo, Susan; Czarnecki-Maulden, Gail; Dunham, Bernadette; Ejeta, Gibesa; Famigilietti, Jay S; Gould, Fred; Hamer, John; Jackson-Smith, Douglas B; Jones, James W; Kebreab, Ermias; Kelley, Stephen S; Leach, Jan E; Lougee, Robin; McCluskey, Jill J; Plaut, Karen I; Salvador, Ricardo J; Sample, V Alaric}, number={3}, journal={AGRICULTURE AND HUMAN VALUES}, author={Rice, Charles W. and Schoen, Robin and Aristidou, Aristos and Burgess, Shane C. and Capalbo, Susan and Czarnecki-Maulden, Gail and Dunham, Bernadette and Ejeta, Gibesa and Famigilietti, Jay S. and Gould, Fred and et al.}, year={2020}, month={Sep}, pages={531–533} }
 @article{scouse_kelley_liang_bergman_2020, title={Regional and net economic impacts of high-rise mass timber construction in Oregon}, volume={61}, ISSN={["2210-6715"]}, DOI={10.1016/j.scs.2020.102154}, abstractNote={Pacific Northwest policy makers are excited about the emergence of mass timber into U.S. construction markets as the product potentially creates local manufacturing jobs while utilizing Douglas fir growing sustainably in the region. This study assessed regional economic impacts generated by mass timber high-rise construction in Oregon. Economic impact estimates were derived using a regionally specific input-output model combined with analysis-by-parts methodology. Financial data from Portland’s 12-story Framework building, estimated using RSMeans software, provided purchasing information. The study’s economic model made use of regionally specific socioeconomic data from the American Community Survey to determine how economic impacts translated into increased earnings for study area residents. Because building with mass timber represented product substitution over traditional construction practices, this study assessed regional impacts of mass timber construction alongside the opportunity costs associated with a concrete frame alternative. Net impact assessment results indicated that construction of the 12-story building using a mass timber design generated larger economic impacts than traditional concrete frame construction and generated additional earnings for households of all income levels. Panels must be produced locally to realize the full economic benefits of mass timber construction as importing panels from outside the state creates economic leakage that reduces economic benefits.}, journal={SUSTAINABLE CITIES AND SOCIETY}, author={Scouse, Adam and Kelley, Stephen S. and Liang, Shaobo and Bergman, Richard}, year={2020}, month={Oct} }
 @article{miller_peralta_mitchell_kelley_chiang_pearson_rottmann_cunningham_peszlen_2019, title={ANATOMICAL, PHYSICAL, AND MECHANICAL PROPERTIES OF TRANSGENIC LOBLOLLY PINE (PINUS TAEDA L.) MODIFIED FOR INCREASED DENSITY}, volume={51}, ISSN={["0735-6161"]}, DOI={10.22382/wfs-2019-018}, abstractNote={Traditional breeding methods are often constrained by the reproductive cycles of tree species and the difficulty in achieving significant improvements to complex traits; therefore, genetic manipulation of complex traits such as wood properties has the potential to resolve those issues. The objectives of this study were to analyze MOE, MOR, and the physical and anatomical properties of 2- to 3-yr-old field-grown transgenic Pinus taeda trees modified for increased density. This investigation consisted of a total of 55 sample trees in two separate experiments. Transgenic trees from sets OX41 and OX55, modified for increased density using two variants of the same HAP5 gene, exhibited higher mechanical properties with smaller stem diameter and tracheid lumen diameter than their set of control trees. In addition, set OX55 exhibited increased cell wall thickness. In the second experiment, the transgenic group WVK249, modified for higher density using an unrelated MYB gene, exhibited similar diameter growth and increased cell wall thickness and lower lumen/cell wall ratios but no change in mechanical properties compared with its control.}, number={2}, journal={WOOD AND FIBER SCIENCE}, author={Miller, Z. D. and Peralta, P. N. and Mitchell, P. H. and Kelley, S. S. and Chiang, V. L. and Pearson, L. and Rottmann, W. H. and Cunningham, M. W. and Peszlen, I. M.}, year={2019}, month={Apr}, pages={173–182} }
 @article{kim_lee_treasure_skotty_floyd_kelley_park_2019, title={Alkaline extraction and characterization of residual hemicellulose in dissolving pulp}, volume={26}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-018-2137-0}, number={2}, journal={CELLULOSE}, author={Kim, Chae Hoon and Lee, Joo and Treasure, Trevor and Skotty, Jennifer and Floyd, Thomas and Kelley, Stephen S. and Park, Sunkyu}, year={2019}, month={Jan}, pages={1323–1333} }
 @article{miller_peralta_mitchell_chiang_kelley_edmunds_peszlen_2019, title={Anatomy and Chemistry of Populus trichocarpa with Genetically Modified Lignin Content}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.3.5729-5746}, abstractNote={Vessel and fiber properties, diameter growth, and chemical compositions were investigated for transgenic Populus trichocarpa (black cottonwood) trees harvested after six months of growth in a greenhouse. Genetic modifications were cinnamyl alcohol dehydrogenase (CAD), cinnamate 3-hydroxylase (C3H), or cinnamate 4-hydroxylase (C4H), which resulted in modified lignin composition or content, and changed the syringyl-to-guaiacyl ratio. Comparing the genetic groups to the wild-type as the control, trees with reduced lignin content showed different results for vessel and fiber properties measured. Genetic groups with reduced PtrC3H3 and PtrC4H1&2 (with lower lignin content and higher S/G ratio than the control) exhibited splitting perpendicular to the rays, yet had the same fiber lumen diameter and the same fiber cell wall thickness as the control. Changes in lignin structure from modifications to PtrCAD resulted in reductions to the number of vessels, increases in vessel and fiber diameters, and had no consistent impact on stem diameter.}, number={3}, journal={BIORESOURCES}, author={Miller, Zachary D. and Peralta, Perry N. and Mitchell, Phil and Chiang, Vincent L. and Kelley, Stephen S. and Edmunds, Charles W. and Peszlen, Ilona M.}, year={2019}, month={Aug}, pages={5729–5746} }
 @book{allison_brown_goddard_guerinot_jansson_jaykus_jensen_khosla_lougee_lowry_et al._2019, title={Science Breakthroughs to Advance Food and Agricultural Research by 2030}, DOI={10.17226/25059}, journal={SCIENCE BREAKTHROUGHS TO ADVANCE FOOD AND AGRICULTURAL RESEARCH BY 2030}, author={Allison, David B. and Brown, Corrie C. and Goddard, Lisa M. and Guerinot, Mary Lou and Jansson, Janet K. and Jaykus, Lee-Ann and Jensen, Helen H. and Khosla, Rajiv and Lougee, Robin and Lowry, Gregory V. and et al.}, year={2019}, pages={1–228} }
 @article{londhe_luo_park_kelley_fang_2019, title={Testing of anisole and methyl acetate as additives to diesel and biodiesel fuels in a compression ignition engine}, volume={246}, ISSN={["1873-7153"]}, url={https://doi.org/10.1016/j.fuel.2019.02.079}, DOI={10.1016/j.fuel.2019.02.079}, abstractNote={This paper investigates the effects of anisole and methyl acetate (as fuel additives) on the performance and emission characteristics of a compression-ignition (i.e., diesel) engine. Anisole and methyl acetate can be obtained from methylation of phenol and acetic acid, respectively. Phenol and acetic acid are compounds which are abundant in bio-oil derived from pyrolysis of wood and is thus renewable in nature. Using methyl acetate as a diesel fuel additive in compression-ignition engines has rarely been reported in the literature. The objective of the current work is to provide testing results of methyl acetate and perform comparisons with anisole as fuel additives for both diesel and biodiesel fuels. The effects of loads, additive type, and base fuels were tested. The tested loads include 0, 1.26, 2.52, and 3.78 bar brake mean effective pressure (BMEP) and the base fuels include No.2 diesel and biodiesel from waste cooking oil. The additive concentrations were kept at 10% by volume. Engine performance, exhaust emissions, and in-cylinder combustion were measured and analyzed. For diesel-anisole (DA) blends, it was seen that the blends were comparable to diesel in terms of performance but with slightly higher fuel consumption rates. HC and CO emissions reduced slightly, however, NOx and soot concentration increased. Diesel-methyl acetate (DM) blends were comparable to diesel in terms of performance with a slight increase in the fuel consumption rates. HC and CO emissions decreased with added methyl acetates. NOx and soot concentration increased. Both anisole and methyl acetate of 10% by volume in biodiesel were tested and it was observed that both blends were slightly better than pure biodiesel in terms of performance. HC and CO emissions reduced for both blends. NOx and soot concentration however increased as compared to pure biodiesel. From the experiments, it is believed that both anisole and methyl acetate can be used as suitable additives to diesel and biodiesel in terms of performance; however, the emissions of NOx and soot can pose a challenge.}, journal={FUEL}, publisher={Elsevier BV}, author={Londhe, Himanshu and Luo, Guanqun and Park, Sunkyu and Kelley, Stephen S. and Fang, Tiegang}, year={2019}, month={Jun}, pages={79–92} }
 @article{edmunds_peszlen_chiang_kelley_miller_davis_gjersing_peralta_2019, title={Thermo-mechanical Behavior of Genetically Modified Populus trichocarpa}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.2.4760-4773}, abstractNote={Wood processing is often performed at elevated temperatures under moisture-saturated conditions; therefore, it is important to understand the impact of the lignin content and lignin chemical structure on the thermo-mechanical properties of wood. In this study, genetically modified Populus trichocarpa wood specimens with down-regulated cinnamyl alcohol dehydrogenase, cinnamate 3-hydroxylase, and cinnamate 4-hydroxylase with altered lignin contents and/or lignin structures were utilized to probe the relationship between the lignin content, lignin monomer composition, and thermo-mechanical properties of solid wood. The thermo-mechanical properties of these unique samples were measured using dynamic mechanical analysis and the nuclear magnetic resonance (NMR) spin-spin relaxation time. The results showed that the transgenic P. trichocarpa samples had decreased storage and loss moduli compared with the wildtype. The solid-state NMR revealed increased lignin molecular mobility in the reduced-lignin transgenic lines. Also, noticeably reduced glass transition temperatures (Tg) were observed in the transgenic lines with reduced lignin contents and altered lignin monomer compositions compared with the wildtype. The increased lignin molecular mobility and reduced Tg in these samples can probably contribute to wood utilization and processing, such as lignin removal for pulp and paper and biofuels production, as well as particle consolidation during wood composite manufacturing.}, number={2}, journal={BIORESOURCES}, author={Edmunds, Charles W. and Peszlen, Ilona and Chiang, Vincent L. and Kelley, Stephen S. and Miller, Zachary D. and Davis, Mark F. and Gjersing, Erica and Peralta, Perry}, year={2019}, month={May}, pages={4760–4773} }
 @article{edmunds_molina_andre_hamilton_park_fasina_adhikari_kelley_tumuluru_rials_et al._2018, title={Blended Feedstocks for Thermochemical Conversion: Biomass Characterization and Bio-Oil Production From Switchgrass-Pine Residues Blends}, volume={6}, ISSN={["2296-598X"]}, DOI={10.3389/fenrg.2018.00079}, abstractNote={An abundant, low-cost, and high-quality supply of lignocellulosic feedstock is necessary to realize the large-scale implementation of biomass conversion technologies capable of producing renewable fuels, chemicals, and products. Barriers to this goal include the variability in the chemical and physical properties of available biomass, and the seasonal and geographic availability of biomass. Blending several different types of biomass to produce consistent feedstocks offers a solution to these problems and allows for control over the specifications of the feedstocks. For thermochemical conversion processes, attributes of interest include carbon content, total ash, specific inorganics, density, particle size, and moisture content. In this work, a series of switchgrass and pine residues blends with varying physical and chemical properties were evaluated. Physical and chemical properties of the pure and blended materials were measured, including compositional analysis, elemental analysis, compressibility, flowability, density, and particle size distribution. To screen blends for thermochemical conversion behavior, the analytical technique, pyrolysis gas chromatography mass spectrometry (Py-GC/MS), was used to analyze the vapor-phase pyrolysis products of the various switchgrass/pine residues blends. The py-GC/MS findings were validated by investigating the bio-oils produced from the selected blends using a lab-scale fluidized-bed pyrolysis reactor system. Results indicate that the physical properties of blended materials are proportional to the blend ratio of pure feedstocks. In addition, pyrolysis of pine residues resulted in bio-oils with higher carbon content and lower oxygen content, while switchgrass derived pyrolysis products contained relatively greater amount of anhydrosugars and organic acids. The distribution of the pyrolysis vapors and isolated bio-oils appear to be a simple linear combination of the two feedstocks. The concentration of alkali and alkaline earth metals (Ca, K, Mg, and Na) in the blended feedstocks were confirmed to be a critical parameter due to their negative effects on the bio-oil yield. This work demonstrates that blending different sources of biomass can be an effective strategy to produce a consistent feedstock for thermochemical conversion.}, journal={FRONTIERS IN ENERGY RESEARCH}, author={Edmunds, Charles W. and Molina, Eliezer A. Reyes and Andre, Nicolas and Hamilton, Choo and Park, Sunkyu and Fasina, Oladiran and Adhikari, Sushil and Kelley, Stephen S. and Tumuluru, Jaya S. and Rials, Timothy G. and et al.}, year={2018}, month={Aug} }
 @article{kim_vinueza_kelley_park_2018, title={Correlation between solubility parameters and recovery of phenolic compounds from fast pyrolysis bio-oil by diesel extraction}, volume={1}, ISSN={2588-9133}, url={http://dx.doi.org/10.1016/J.CRCON.2018.08.004}, DOI={10.1016/J.CRCON.2018.08.004}, abstractNote={Fast pyrolysis bio-oils (fpBO) were extracted with two alternative commercial transportation fuels, hydrocarbon diesel and bio-diesel. The extraction of fpBO with commercial diesel fuel provided a yield of 4.3 wt%, but the yield increased significantly to 26.6 wt% when bio-diesel was the extractant. The molecular weight of fpBO before and after extraction were consistent with the loss of a more soluble, low molecular weight fraction from the crude fpBO. The relative energy difference (RED), based on the Hansen solubility parameter (HSP), is used to examine the extraction efficiency of specific compounds in the two different ‘solvents’. Differences in the RED values could be used to rationalize differences in the partitioning of common fpBO phenolics.}, number={3}, journal={Carbon Resources Conversion}, publisher={Elsevier BV}, author={Kim, Hoyong and Vinueza, Nelson R. and Kelley, Stephen S. and Park, Sunkyu}, year={2018}, month={Dec}, pages={238–244} }
 @article{yoo_chung_kelley_park_2018, title={Graphitization Behavior of Loblolly Pine Wood Investigated by in Situ High Temperature X-ray Diffraction}, volume={6}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.8b01446}, abstractNote={Graphitization is a complex process involving chemical and morphological changes, although the detailed mechanism for different starting materials is not well understood. In this work, in situ high temperature X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to examine the phase transition occurring between 1000 and 1500 °C in loblolly pine wood-derived carbon materials. Electron energy loss spectroscopy (EELS) was also used to study these wood-derived carbon materials. XRD data showed the disappearance of a disordered carbon phase between 1300 and 1400 °C, followed by the formation of a crystalline graphitic phase between 1400 and 1500 °C. Lattice parameters and the crystal structure of the loblolly pine wood-derived graphite were systematically calculated from the empirical data. The presence of a large endothermic peak at 1500 °C in the DSC thermogram supported this observation. Selected area electron diffraction patterns showed the growth of graphitic crystallites after he...}, number={7}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Yoo, Seunghyun and Chung, Ching-Chang and Kelley, Stephen S. and Park, Sunkyu}, year={2018}, month={Jul}, pages={9113–9119} }
 @article{ou_kim_kelley_park_2018, title={Impacts of feedstock properties on the process economics of fast-pyrolysis biorefineries}, volume={12}, ISSN={["1932-1031"]}, DOI={10.1002/bbb.1860}, abstractNote={Abstract}, number={3}, journal={BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR}, author={Ou, Longwen and Kim, Hoyong and Kelley, Stephen and Park, Sunkyu}, year={2018}, pages={442–452} }
 @article{yoo_kelley_tilotta_park_2018, title={Structural Characterization of Loblolly Pine Derived Biochar by X-ray Diffraction and Electron Energy Loss Spectroscopy}, volume={6}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/ACSSUSCHEMENG.7B04119}, DOI={10.1021/ACSSUSCHEMENG.7B04119}, abstractNote={Biochar from lignocellulosic biomass is emerging as a sustainable material with versatile applications, but its detailed properties are poorly understood because of its structural complexity. We propose a biochar structural development model based on experimental results including composition analysis, surface area and pore analysis, X-ray diffraction analysis, electron microscopy imaging, and electron energy loss spectroscopy. Loblolly pine derived biochars were produced at different carbonization temperatures between 300 to 1000 °C. Fixed carbon, sp2 content, and number of graphene layers increased with increased carbonization temperature. Alternating average C–C bond length, interlayer spacing distance, and layer coherence length were observed. Bulk plasmon excitation energy was correlated to the average C–C bond length, and it serves as a good indicator of the carbon structure development when compared to the perfect graphitic carbon structure. On the basis of the experimental results, four different ...}, number={2}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Yoo, Seunghyun and Kelley, Stephen S. and Tilotta, David C. and Park, Sunkyu}, year={2018}, month={Jan}, pages={2621–2629} }
 @article{reeb_phillips_venditti_treasure_daystar_gonzalez_jameel_kelley_2018, title={Techno‐economic analysis of various biochemical conversion platforms for biosugar production: Trade‐offs of co‐producing biopower versus pellets for either a greenfield, repurpose, or co‐location siting context}, volume={12}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/bbb.1847}, DOI={10.1002/bbb.1847}, abstractNote={Abstract}, number={3}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Reeb, Carter and Phillips, Richard and Venditti, Richard and Treasure, Trevor and Daystar, Jesse and Gonzalez, Ronalds and Jameel, Hasan and Kelley, Stephen}, year={2018}, month={Feb}, pages={390–411} }
 @article{ou_luo_ray_li_hu_kelley_park_2018, title={Understanding the Impacts of Biomass Blending on the Uncertainty of Hydrolyzed Sugar Yield from a Stochastic Perspective}, volume={6}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/ACSSUSCHEMENG.8B02150}, DOI={10.1021/ACSSUSCHEMENG.8B02150}, abstractNote={Feedstock price and availability are key challenges for biorefinery development. Biomass blending has been suggested as a route to overcome these limitations. However, the impacts of feedstock blending on the uncertainty in hydrolyzed sugar yields remain unclear. This study quantifies the uncertainties in the sugar yields from hydrolysis of the blends of corn stover, switchgrass, and grass clippings by considering both feedstock compositional variation and model uncertainty. The results indicate that feedstock blending reduces the uncertainties in sugar yields and delivers feedstock of more uniform quality. A 60/35/5 blend of corn stover, switchgrass, and grass clippings on average achieves a glucose yield of 32.6 g/100 g of biomass, which is comparable to those of corn stover (33.3 g/100 g) and switchgrass (32.9 g/100 g), but drastically higher than that of grass clippings (21.7 g/100 g). This same blend also achieves the lowest variance in glucose yield (2.9 g/100 g) compared to corn stover (3.1 g/100 g...}, number={8}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Ou, Longwen and Luo, Guanqun and Ray, Allison and Li, Chenlin and Hu, Hongqiang and Kelley, Stephen and Park, Sunkyu}, year={2018}, month={Jun}, pages={10851–10860} }
 @article{scouse_mcconnell_kelley_venditti_2017, title={Analysis of North Carolina Forest Industry Earnings: Adapting Household-Level Data from the American Community Survey to a Social Accounting Matrix}, volume={116}, ISSN={0022-1201}, url={http://dx.doi.org/10.5849/jof-2017-032}, DOI={10.5849/jof-2017-032}, number={2}, journal={Journal of Forestry}, publisher={Oxford University Press (OUP)}, author={Scouse, Adam and McConnell, Eric and Kelley, Stephen and Venditti, Richard}, year={2017}, pages={101–108} }
 @article{edmunds_peralta_kelley_chiang_sharma-shivappa_davis_harman-ware_sykes_gjersing_cunningham_et al._2017, title={Characterization and enzymatic hydrolysis of wood from transgenic Pinus taeda engineered with syringyl lignin or reduced lignin content}, volume={24}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-017-1231-z}, abstractNote={Softwood is an abundant resource; however, currently its utilization for bioconversion to obtain platform sugars is limited. Pinus taeda trees which were genetically modified to either produce S lignin or to decrease lignin content were characterized with a suite of analytic techniques. Syringyl lignin was visualized in the secondary xylem of one genetic line with Mäule staining. Solid-state nuclear magnetic resonance identified the S lignin units were coupled into the lignin through β-O-4 linkages, and thioacidolysis measured approximately 13% S lignin content in the same sample. Reductions of the lignin of as much as 33% were observed in the transgenics. To better understand how these modifications affect bioconversion, their amenability to hot water and dilute acid pretreatments and enzymatic hydrolysis was evaluated. Lignin reductions resulted in 1.9–3.2-fold increases in glucose release compared to the control. However, no apparent benefit was observed by S lignin incorporation at the concentrations reported in this study. These results highlight the potential for softwood cell wall properties to be improved for bioenergy/biochemical applications.}, number={4}, journal={CELLULOSE}, author={Edmunds, Charles W. and Peralta, Perry and Kelley, Stephen S. and Chiang, Vincent L. and Sharma-Shivappa, Ratna R. and Davis, Mark F. and Harman-Ware, Anne E. and Sykes, Robert W. and Gjersing, Erica and Cunningham, Michael W. and et al.}, year={2017}, month={Apr}, pages={1901–1914} }
 @article{leskinen_kelley_argyropoulos_2017, title={E-beam irradiation & steam explosion as biomass pretreatment, and the complex role of lignin in substrate recalcitrance}, volume={103}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2017.05.008}, DOI={10.1016/j.biombioe.2017.05.008}, abstractNote={Sequential electron beam-steam explosion (EB-SE) pretreatment was applied to hardwood (Birch) and softwood (Pine) substrates in an effort to enhance their enzymatic saccharification. The effect of these two pretreatments on the structure and composition of the individual cell wall components was examined. The combination of these treatments showed a synergistic effect on the conversion of hemicelluloses into water soluble oligomers, and enhanced the overall enzymatic saccharification of wood substrates. Even after the combined pretreatment Pine was more recalcitrant than Birch, which was attributed to differences in the lignin. Model systems created from cellulose and isolated high molecular weight (HMW) lignin fractions were found to inhibit enzymatic conversion of cellulose by 20% over a control. This inhibition is likely related to the unproductive binding of the cellulose enzymes to the HMW lignin. Additionally, the presence of the HMW lignin reduces the swelling capacity of the wood substrate, and thus its accessibility to enzymes. Conversely, low molecular weight lignin fragments were found to be slightly beneficial for enzymatic hydrolysis of cellulose substrates. These results provide insight to the complex interactions between lignin and cellulase enzymes, and highlight the need for pretreatment processes that can effectively cleave lignin into oligomeric fragments.}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Leskinen, Timo and Kelley, Stephen S. and Argyropoulos, Dimitris S.}, year={2017}, month={Aug}, pages={21–28} }
 @article{ren_meng_chang_kelley_jameel_park_2017, title={Effect of blending ratio of loblolly pine wood and bark on the properties of pyrolysis bio-oils}, volume={167}, ISSN={["1873-7188"]}, DOI={10.1016/j.fuproc.2017.06.025}, abstractNote={Bark, which is available in abundance, has recently become a topic of interest when considering alternative materials for the production of pyrolysis bio-oil. Previous studies have revealed that the pyrolysis behavior of bark differs remarkably from that of wood in that bark typically generates a phase-separated bio-oil. In this study, blends of loblolly pine wood and bark were pyrolyzed to investigate the effect of blending ratio on the yield and properties of derived bio-oils. Trends of lower decomposition rate, decreased organic yield, and increased bio-char yield were observed as bark percentage in the feedstock increased, while the amount of levoglucosan in bio-oil increased. Pyrolysis reactivity, which includes yield and physical properties of the bio-oil, was found to have a linear relationship with the blending ratio of pine bark. It was found that blending up to 50% bark in the feedstock still produced a homogeneous bio-oil.}, journal={FUEL PROCESSING TECHNOLOGY}, author={Ren, Xueyong and Meng, Jiajia and Chang, Jianmin and Kelley, Stephen S. and Jameel, Hasan and Park, Sunkyu}, year={2017}, month={Dec}, pages={43–49} }
 @misc{rajagopalan_kelley_2017, title={Evaluating Sustainability of Buildings Using Multi-Attribute Decision Tools}, volume={67}, ISSN={["0015-7473"]}, DOI={10.13073/fpj-d-16-00028}, abstractNote={Abstract Developing tools and methodologies for the evaluation of sustainable buildings is essential to promote transparency in the building design community. Building sustainability includes attributes from the built, natural, and social systems and inherently requires a series of trade-offs. These complex and often competing priorities require consideration at each stage of a building's life cycle. A total of 24 environmental, social, and economic indicators were developed and applied to three alternative building systems: cross-laminated timber (CLT), steel and glass, and reinforced concrete. The goal of this study was to demonstrate the use of a multi-attribute decision support system (MADSS) that uses a series of indicators, assigns numerical values to these indicators, and then allows for systematic evaluation and ranking of alternatives. A case study approach was used to demonstrate the utility of the MADSS approach in identifying “hot spots” and trade-offs for the three building systems. Portland,...}, number={3-4}, journal={FOREST PRODUCTS JOURNAL}, author={Rajagopalan, Neethi and Kelley, Stephen S.}, year={2017}, pages={179–189} }
 @article{assis_gonzalez_kelley_jameel_bilek_daystar_handfield_golden_prestemon_singh_et al._2017, title={Risk management consideration in the bioeconomy}, volume={11}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/bbb.1765}, DOI={10.1002/bbb.1765}, abstractNote={Abstract}, number={3}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Assis, C. A. and Gonzalez, R. and Kelley, S. and Jameel, H. and Bilek, T. and Daystar, J. and Handfield, R. and Golden, J. and Prestemon, J. and Singh, D. and et al.}, year={2017}, month={Apr}, pages={549–566} }
 @article{arteaga-pérez_grandón_flores_segura_kelley_2017, title={Steam torrefaction of Eucalyptus globulus for producing black pellets: A pilot-scale experience}, volume={238}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2017.04.037}, DOI={10.1016/j.biortech.2017.04.037}, abstractNote={Steam torrefaction of Eucalyptus globulus was performed at temperatures between 245 °C and 265 °C in a 100 kg/h pilot plant. Torrefied biomass was then pelletized in a 300 kg/h unit and the pellets were subject to durability, density and combustion tests. The structural changes measured with FTIR were studied along with the combustion behavior of the materials. Compositional analysis showed that increasing the torrefaction temperature reduced both hemicellulose fraction and overall mass yield (MY). Furthermore, there was a linear relationship between the energy yield (EY) and mass yield (EY = [1.04−0.9(1−MY)]) for these samples. The ignition and comprehensive indexes confirmed that the stability of the torrefied biomass in a combustion environment was higher than for untreated biomass. Finally, pellets showed high durability (98%), and had an energy density (13–14 GJ/m3), which is comparable to low-rank coals.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Arteaga-Pérez, Luis E. and Grandón, Héctor and Flores, Mauricio and Segura, Cristina and Kelley, Stephen S.}, year={2017}, month={Aug}, pages={194–204} }
 @article{radics_gonzalez_bilek_kelley_2017, title={Systematic Review of Torrefied Wood Economics}, volume={12}, ISSN={["1930-2126"]}, DOI={10.15376/biores.12.3.radics}, abstractNote={This literature review aims to provide a systematic analysis of studies on the financial aspects of producing torrefied biomass and torrefied pellets. There are substantial differences in the specific technologies, operating conditions, scale of the demonstration, and properties of biomass feedstock. There is a lack of reports that consider the entire supply chain, which is required for an understanding of the high-cost steps. To obtain a robust view of the torrefaction processes’ financial prospects the authors have used both peer-reviewed and non-peer-reviewed papers that allowed the researchers to include thirty-one papers in this analysis. All these studies establish that the prices of the biomass and the final torrefied product are critical. The product yield and caloric content, which are related to pricing, were also key financial drivers. The lower freight costs due to high-energy density of the torrefied pellets was recognized and calculated, but some other benefits were not quantified. There is a need for a detailed and flexible torrefaction financial model that includes variations in financial assumptions and biomass properties. Given the uncertainty around many specific steps, there is value in including stochastic tools in these financial analyses.}, number={3}, journal={BIORESOURCES}, author={Radics, Robert I. and Gonzalez, Ronalds and Bilek, Edward M. and Kelley, Stephen S.}, year={2017}, pages={6868–6884} }
 @article{daystar_venditti_kelley_2016, title={Dynamic greenhouse gas accounting for cellulosic biofuels: implications of time based methodology decisions}, volume={22}, ISSN={0948-3349 1614-7502}, url={http://dx.doi.org/10.1007/s11367-016-1184-8}, DOI={10.1007/s11367-016-1184-8}, number={5}, journal={The International Journal of Life Cycle Assessment}, publisher={Springer Science and Business Media LLC}, author={Daystar, Jesse and Venditti, Richard and Kelley, Stephen S.}, year={2016}, month={Nov}, pages={812–826} }
 @article{reeb_venditti_gonzalez_kelley_2016, title={Environmental LCA and Financial Analysis to Evaluate the Feasibility of Bio-based Sugar Feedstock Biomass Supply Globally: Part 2. Application of Multi-Criteria Decision-Making Analysis as a Method for Biomass Feedstock Comparisons}, volume={11}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.11.3.6062-6084}, DOI={10.15376/biores.11.3.6062-6084}, abstractNote={Early-stage evaluation of biofuel and bioproduct technologies is extremely complicated and involves many disparate feasibility criteria, including technical, financial, environmental, logistic, legal, social, and other aspects. Problems can arise for decision-makers when evaluating renewable technologies at this early stage due to bias, shifting preferences or priorities, occurrence of trade-offs, and decision-making complexity. Thus, a method is needed for evaluating disparate, typically non-comparable criteria concurrently. In Part 1 of this research, cradle-to-grave environmental LCA was conducted for biomass delivery to a biosugar refinery using Ecoinvent v2.2 data and the TRACI 2 impact assessment method for midpoint impacts. Biomass availability, delivered cost, sugar yield, transportation distance, harvestable months per year, and other aspects of supply chain feasibility were measured for eighteen feedstock biomass types. In Part 2, stochastic multi-attribute analysis (SMAA) was used alongside LCA to develop an environmental preference single-score probability distribution function for feedstock alternatives. Weighted single-scoring and ranking, using multi-criteria decision-making analysis (MCDA), was conducted considering five criteria of biomass supply feasibility: biomass delivered cost, biosugar yield, harvestable months, transport distance, and environmental preference single-score. Corn was shown to cost the most, followed by switchgrass and U.S. primary forest products. Transport distance was found to be highest for residues due to low yield per acre and low covered area. Results of MCDA show that Brazilian eucalyptus and Malaysian empty fruit bunch biomass types were consistently preferred relative to other biomass types. In the U.S., Genera biomass sorghum is most holistically preferred. It is shown that SMAA is helpful for translating LCA data for decision science. It was shown that MCDA can be useful for early-stage biorefinery technology commercialization decision-making, using the novel decision science tool described herein.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Reeb, Carter Walker and Venditti, Richard and Gonzalez, Ronalds and Kelley, Stephen}, year={2016}, month={May}, pages={6062–6084} }
 @article{wang_kelley_venditti_2016, title={Lignin-Based Thermoplastic Materials}, volume={9}, ISSN={1864-5631}, url={http://dx.doi.org/10.1002/cssc.201501531}, DOI={10.1002/cssc.201501531}, abstractNote={Abstract}, number={8}, journal={ChemSusChem}, publisher={Wiley}, author={Wang, Chao and Kelley, Stephen S. and Venditti, Richard A.}, year={2016}, month={Apr}, pages={770–783} }
 @article{rajagopalan_venditti_kelley_daystar_2016, title={Multi‐attribute uncertainty analysis of the life cycle of lignocellulosic feedstock for biofuel production}, volume={11}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/BBB.1737}, DOI={10.1002/BBB.1737}, abstractNote={Abstract}, number={2}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Rajagopalan, Neethi and Venditti, Richard and Kelley, Steve and Daystar, Jesse}, year={2016}, month={Dec}, pages={269–280} }
 @article{radics_dasmohapatra_kelley_2016, title={Public perception of bioenergy in North Carolina and Tennessee}, volume={6}, ISSN={["2192-0567"]}, DOI={10.1186/s13705-016-0081-0}, abstractNote={The goal of the study is to examine the general public’s understanding and perceptions of bioenergy and biofuels in North Carolina (NC) and Tennessee (TN). The study focuses on the public concerns, support and risk evaluations of alternative bioenergy feedstocks and biofuels, and includes an assessment of the economic, environmental, social, and policy impacts of bioenergy production and use. A sample of consumers in NC and TN were surveyed in the fall of 2013 and spring of 2014 for their perceptions about bioenergy and specifically, biofuels for transportation. Five hundred eighty-six consumers completed the questionnaire electronically (376 in NC and 210 in TN). Respondents reported that the price and vehicle compatibility with biomass-based transportation fuels were the most important factors in their choice of biofuels over gasoline at a pump. Results show that the acceptance of bioenergy depends on the extent of knowledge and available information to consumers about the energy source. A principal component analysis (PCA) indicated seven distinct dimensions of consumer’s perception about bioenergy. The key dimensions are the following: how bioenergy benefits the society, risks of bioenergy use, government support for bioenergy, increase in food cost, conditional use of trees, support for low-cost biofuel alternative to current energy, and market attributes of bioenergy purchase. The findings from this study reflect the need for communicating the benefits and risks from the use of bioenergy to the general public through trustworthy channels of communication and targeted policy, market, and institutional support.}, journal={ENERGY SUSTAINABILITY AND SOCIETY}, author={Radics, Robert I. and Dasmohapatra, Sudipta and Kelley, Stephen S.}, year={2016}, month={Jun} }
 @article{radics_dasmohapatra_kelley_2016, title={Use of linear programming to -optimize the social, −environmental, and economic impacts of using woody feedstocks for pellet and -torrefied pellet production}, volume={10}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1658}, DOI={10.1002/bbb.1658}, abstractNote={Abstract}, number={4}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Radics, Robert I. and Dasmohapatra, Sudipta and Kelley, Stephen S.}, year={2016}, month={May}, pages={446–461} }
 @article{leskinen_kelley_argyropoulos_2015, title={Determination of molecular weight distributions in native and pretreated wood}, volume={119}, ISSN={0144-8617}, url={http://dx.doi.org/10.1016/J.CARBPOL.2014.11.026}, DOI={10.1016/J.CARBPOL.2014.11.026}, abstractNote={The analysis of native wood components by size-exclusion chromatography (SEC) is challenging. Isolation, derivatization and solubilization of wood polymers is required prior to the analysis. The present approach allowed the determination of molecular weight distributions of the carbohydrates and of lignin in native and processed woods, without preparative component isolation steps. For the first time a component selective SEC analysis of sawdust preparations was made possible by the combination of two selective derivatization methods, namely; ionic liquid assisted benzoylation of the carbohydrate fraction and acetobromination of the lignin in acetic acid media. These were optimized for wood samples. The developed method was thus used to examine changes in softwood samples after degradative mechanical and/or chemical treatments, such as ball milling, steam explosion, green liquor pulping, and chemical oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The methodology can also be applied to examine changes in molecular weight and lignin-carbohydrate linkages that occur during wood-based biorefinery operations, such as pretreatments, and enzymatic saccharification.}, journal={Carbohydrate Polymers}, publisher={Elsevier BV}, author={Leskinen, Timo and Kelley, Stephen S. and Argyropoulos, Dimitris S.}, year={2015}, month={Mar}, pages={44–52} }
 @article{reeb_venditti_hays_daystar_gonzalez_kelley_2015, title={Environmental LCA and financial analysis to evaluate the feasibility of bio-based sugar feedstock biomass supply globally: Part 1. supply chain analysis}, volume={10}, DOI={10.15376/biores.10.4.8098-8134}, abstractNote={Chemical production from crude oil represents a substantial percentage of the yearly fossil fuel use worldwide, and this could be partially offset by renewable feedstocks such as woody biomass and energy crops. Past techno-economic and environmental analyses have been conducted for isolated feedstocks on a regional or national scope. This study encompasses complete supply chain logistics analysis, delivered cost financial analysis, national availability, and environmental life cycle assessment (LCA) for 18 selected cellulosic feedstocks from around the world. A biochemical conversion route to monomeric sugars is assumed for estimated sugar yields and biosugar feedstock cost analysis. US corn grain was determined to have the highest delivered cost, while rice hulls in Indonesia resulted in the lowest cost of the feedstocks studied. Monomeric sugar yields from literature ranged from 358 kg BDMT-1 for US forest residues to 700 kg BDMT-1 for corn syrup. Environmental LCA was conducted in SimaPro using ecoinvent v2.2 data and the TRACI 2 impact assessment method for mid-point impacts cradle-to-incoming biorefinery gate. Carbon absorption during biomass growth contributed most substantially to the reduction of net global warming potential. Rice hulls and switchgrass resulted in the highest global warming potential, followed closely by corn and Thai sugarcane bagasse. Contribution analysis shows that chemical inputs such as fertilizer use contribute substantially to the net environmental impacts for these feedstocks.}, number={4}, journal={BioResources}, author={Reeb, C. W. and Venditti, R. and Hays, T. and Daystar, J. and Gonzalez, R. and Kelley, Stephen}, year={2015}, pages={8098–8134} }
 @article{daystar_treasure_reeb_venditti_gonzalez_kelley_2015, title={Environmental impacts of bioethanol using the NREL biochemical conversion route: multivariate analysis and single score results}, volume={9}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1553}, DOI={10.1002/bbb.1553}, abstractNote={Abstract}, number={5}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Daystar, Jesse and Treasure, Trevor and Reeb, Carter and Venditti, Richard and Gonzalez, Ronalds and Kelley, Steve}, year={2015}, month={May}, pages={484–500} }
 @article{daystar_reeb_gonzalez_venditti_kelley_2015, title={Environmental life cycle impacts of cellulosic ethanol in the Southern U.S. produced from loblolly pine, eucalyptus, unmanaged hardwoods, forest residues, and switchgrass using a thermochemical conversion pathway}, volume={138}, ISSN={0378-3820}, url={http://dx.doi.org/10.1016/J.FUPROC.2015.04.019}, DOI={10.1016/J.FUPROC.2015.04.019}, abstractNote={The cradle-to-grave environmental impacts of thermochemical ethanol from loblolly pine, eucalyptus, unmanaged hardwoods, forest residues, and switchgrass biomass feedstocks were determined and compared to gasoline. The Tool for the Reduction and Assessment of Chemical and Other Impacts (TRACI) method was implemented in SimaPro 7.3 to calculate midpoint environmental impacts. Two normalization value sets were used and weighting was performed to produce a single environmental score. Greenhouse gas (GHG) emission reductions of cellulosic ethanol as compared to gasoline were 65%–77%, depending on the biomass feedstock, qualifying these biofuels as cellulosic ethanol under the Renewable Fuel Standards (RFS2). Effects of direct land-use change were significant (~ 18%) and could increase the GHG emissions for switchgrass derived ethanol above the federal GHG reduction thresholds for cellulosic ethanol. The production and use of cellulosic ethanol reduced fossil fuel consumption by between 95% and 97% and by 81% for forest and switchgrass derived ethanol, respectively. Cellulosic ethanol, however, did not reduce all environmental impact categories (e.g., eutrophication, ozone depletion respiratory effects, acidification, and smog) compared to gasoline. The fuel scenario ranking from lowest impact to highest impact consistently remained the same for GHG emissions, fossil fuel use, and the two single weight score analysis methods and was, in ascending order, forest residues with no forest establishment burdens, forest residues with forest establishment burdens, natural hardwood, pine, switchgrass, and finally gasoline. The GHG emission reductions from the use of cellulosic ethanol at the renewable fuel standards mandated production volume of 16 billion gallons of cellulosic ethanol per year by 2020 would result in 9–10 billion metric tonnes of GHG emissions avoided.}, journal={Fuel Processing Technology}, publisher={Elsevier BV}, author={Daystar, Jesse and Reeb, Carter and Gonzalez, Ronalds and Venditti, Richard and Kelley, Stephen S.}, year={2015}, month={Oct}, pages={164–174} }
 @article{leskinen_kelley_argyropoulos_2015, title={Refining of Ethanol Biorefinery Residues to Isolate Value Added Lignins}, volume={3}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.5b00337}, abstractNote={The isolation of lignin coproducts from the residual solids of a hardwood based biocatalytic bioethanol process was examined, using extraction methods based on aqueous alkali or aqueous ethanol. This work focused on understanding how the structural features of raw lignin in the process residue influenced the refined lignin isolation yields, in addition to polymeric and structural characteristics. On the basis of this approach, the extraction based lignin refining could be optimized. Mild extraction conditions allowed for recovery of approximately 40 wt % of the lignin present in the starting material. This yield could be increased to about 76 wt %, by the application of base or acid catalyzed reactive extraction conditions liberating the bonded insoluble fractions of the residue. All isolated lignin products were characterized in terms of their functional groups, molecular weights and thermal properties. The lignins from mild alkali and ethanol extractions showed similarities in their chemical profiles. I...}, number={7}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Leskinen, Timo and Kelley, Stephen S. and Argyropoulos, Dimitris S.}, year={2015}, month={Jul}, pages={1632–1641} }
 @article{radics_dasmohapatra_kelley_2015, title={Systematic review of bioenergy perception studies}, volume={10}, DOI={10.15376/biores.10.4.radics}, abstractNote={This paper presents the results of a structured review of published articles that discuss stakeholders’ perceptions of bioenergy, including both biofuels and biopower. An electronic search process using numerous key terms identified 44 peer-reviewed publications from 2000 to 2013 that focused on stakeholders’ perceptions, understanding, and acceptance of bioenergy. These findings indicate that in the last decade the research community has been more active in publications focused on the societal and public perceptions of the bioenergy industry compared to prior years. Among the reviewed studies, most (84%) are based in the US and Europe, and only a few recent studies have focused on stakeholders in Asia and other parts of the world. This review revealed no standardized methods for evaluation of stakeholder perception, for data collection, or statistical analysis of the data. Among stakeholder groups, the majority of studies focused on the general public or the consumer’s opinion about bioenergy (79% of studies). Overall findings show that the stakeholder groups show low to moderate support for the bioenergy industry. As anticipated, the stakeholder groups had varied views about the opportunities and risks associated with bioenergy industry, and these views varied based on their experiences.}, number={4}, journal={BioResources}, author={Radics, R. and Dasmohapatra, S. and Kelley, Stephen}, year={2015}, pages={8770–8794} }
 @article{daystar_treasure_gonzalez_reeb_venditti_kelley_2015, title={The NREL biochemical and thermochemical ethanol conversion processes: Financial and environmental analysis comparison}, volume={10}, DOI={10.15376/biores.10.3.5096-5116}, abstractNote={The financial and environmental performance of the National Renewable Energy Lab’s (NREL) thermochemical and biochemical biofuel conversion processes are examined herein with pine, eucalyptus, unmanaged hardwood, switchgrass, and sweet sorghum. The environmental impacts of the process scenarios were determined by quantifying greenhouse gas (GHG) emissions and TRACI impacts. Integrated financial and environmental performance metrics were introduced and used to examine the biofuel production scenarios. The thermochemical and biochemical conversion processes produced the highest financial performance and lowest environmental impacts when paired with pine and sweet sorghum, respectively. The high ash content of switchgrass and high lignin content of loblolly pine lowered conversion yields, resulting in the highest environmental impacts and lowest financial performance for the thermochemical and biochemical conversion processes, respectively. Biofuel produced using the thermochemical conversion process resulted in lower TRACI single score impacts and somewhat lower GHG emissions per megajoule (MJ) of fuel than using the biochemical conversion pathway. The cost of carbon mitigation resulting from biofuel production and corresponding government subsidies was determined to be higher than the expected market carbon price. In some scenarios, the cost of carbon mitigation was several times higher than the market carbon price, indicating that there may be other more cost-effective methods of reducing carbon emissions.}, number={3}, journal={BioResources}, author={Daystar, J. and Treasure, T. and Gonzalez, R. and Reeb, C. and Venditti, R. and Kelley, Stephen}, year={2015}, pages={5096–5116} }
 @article{meng_moore_tilotta_kelley_adhikari_parkt_2015, title={Thermal and Storage Stability of Bio-Oil from Pyrolysis of Torrefied Wood}, volume={29}, ISSN={["1520-5029"]}, DOI={10.1021/acs.energyfuels.5b00929}, abstractNote={The objective of this paper is to investigate the biomass torrefaction effect on bio-oil stability by comparing the physicochemical and compositional properties of aged bio-oils. Two aging methods, accelerated aging (held at 80 °C for 24 h) and long-term natural aging (12-month storage at 25 °C), were employed to produce aged bio-oils for such comparison. The results indicate that bio-oils made from heat-treated wood had similar aging behavior in terms of increase of water content, acid content, molecular weight, and viscosity. The increase rate, however, was found to be different and dependent on the aging method. The accelerated method found parallel water and total acidity number (TAN) increments between raw and torrefaction bio-oils, while the natural aging method found torrefaction bio-oils, especially those made from heavily treated wood, had much slower water and acid accumulation than that of raw bio-oil. As a negative effect, both methods identified the viscosity of torrefaction bio-oils increase...}, number={8}, journal={ENERGY & FUELS}, author={Meng, Jiajia and Moore, Andrew and Tilotta, David C. and Kelley, Stephen S. and Adhikari, Sushil and Parkt, Sunkyu}, year={2015}, month={Aug}, pages={5117–5126} }
 @article{leskinen_salas_kelley_argyropoulos_2015, title={Wood Extractives Promote Cellulase Activity on Cellulosic Substrates}, volume={16}, ISSN={1525-7797 1526-4602}, url={http://dx.doi.org/10.1021/ACS.BIOMAC.5B00889}, DOI={10.1021/ACS.BIOMAC.5B00889}, abstractNote={Deposition of hydrophobic wood extractives and representative model compounds, on the surface of cellulose prior to enzymatic hydrolysis was found to either enhance or inhibit the action of cellulase enzymes. The effect of these compounds was correlated with their chemical structure, which may in part explain the differential effects observed between softwood and hardwood extractives. Specifically, the addition of sterol, enhanced enzymatic hydrolysis of microcrystalline cellulose by 54%, whereas the addition of a triglyceride could inhibit the hydrolysis by 49%. The effects of the different extractives' could be explained by considering their Hansen solubility parameters. The amphiphilic and/or hydrophobic character of model extractives was found to be the variable that affected the deposition of extractives on cellulose surfaces and the eventual adsorption of cellulolytic enzymes on it. The observed beneficial effects of extractives are likely related to a reduction in the irreversible binding of the enzymes on the cellulose surface.}, number={10}, journal={Biomacromolecules}, publisher={American Chemical Society (ACS)}, author={Leskinen, Timo and Salas, Carlos and Kelley, Stephen S. and Argyropoulos, Dimitris S.}, year={2015}, month={Sep}, pages={3226–3234} }
 @article{daystar_gonzalez_reeb_venditti_treasure_abt_kelley_2014, title={Economics, environmental impacts, and supply chain analysis of cellulosic biomass for biofuels in the Southern US: pine, eucalyptus, unmanaged hardwoods, forest residues, switchgrass, and sweet sorghum}, volume={9}, DOI={10.15376/biores.9.1.393-444}, abstractNote={The production of six regionally important cellulosic biomass feedstocks, including pine, eucalyptus, unmanaged hardwoods, forest residues, switchgrass, and sweet sorghum, was analyzed using consistent life cycle methodologies and system boundaries to identify feedstocks with the lowest cost and environmental impacts. Supply chain analysis was performed for each feedstock, calculating costs and supply requirements for the production of 453,592 dry tonnes of biomass per year. Cradle-to-gate environmental impacts from these modeled supply systems were quantified for nine mid-point indicators using SimaPro 7.2 LCA software. Conversion of grassland to managed forest for bioenergy resulted in large reductions in GHG emissions due to carbon uptake associated with direct land use change. By contrast, converting forests to cropland resulted in large increases in GHG emissions. Production of forest-based feedstocks for biofuels resulted in lower delivered cost, lower greenhouse gas (GHG) emissions, and lower overall environmental impacts than the agricultural feedstocks studied. Forest residues had the lowest environmental impact and delivered cost per dry tonne. Using forest-based biomass feedstocks instead of agricultural feedstocks would result in lower cradle-to-gate environmental impacts and delivered biomass costs for biofuel production in the southern U.S.}, number={1}, journal={BioResources}, author={Daystar, J. and Gonzalez, R. and Reeb, C. and Venditti, R. and Treasure, T. and Abt, R. and Kelley, Stephen}, year={2014}, pages={393–444} }
 @article{meng_smirnova_song_moore_ren_kelley_park_tilotta_2014, title={Identification of free radicals in pyrolysis oil and their impact on bio-oil stability}, volume={4}, ISSN={["2046-2069"]}, DOI={10.1039/c4ra02007c}, abstractNote={The existence of radicals in pyrolysis oil generated from loblolly pine in three different reactor systems was verified with electron paramagnetic resonance (EPR) spectroscopy.}, number={56}, journal={RSC ADVANCES}, author={Meng, Jiajia and Smirnova, Tatyana I. and Song, Xiao and Moore, Andrew and Ren, Xueyong and Kelley, Stephen and Park, Sunkyu and Tilotta, David}, year={2014}, pages={29840–29846} }
 @article{treasure_gonzalez_jameel_phillips_park_kelley_2014, title={Integrated conversion, financial, and risk modeling of cellulosic ethanol from woody and non-woody biomass via dilute acid pre-treatment}, volume={8}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1494}, DOI={10.1002/bbb.1494}, abstractNote={Abstract}, number={6}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Treasure, Trevor and Gonzalez, Ronalds and Jameel, Hasan and Phillips, Richard B. and Park, Sunkyu and Kelley, Steve}, year={2014}, month={May}, pages={755–769} }
 @article{reeb_hays_venditti_gonzalez_kelley_2014, title={Supply Chain Analysis, Delivered Cost, and Life Cycle Assessment of Oil Palm Empty Fruit Bunch Biomass for Green Chemical Production in Malaysia}, volume={9}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.9.3.5385-5416}, DOI={10.15376/biores.9.3.5385-5416}, abstractNote={Financial, environmental, and supply chain analyses of empty fruit bunch (EFB) biomass are needed for the development of a sustainable green chemicals industry in Malaysia. Herein, holistic analysis of the supply system and EFB life cycle cradle-to-gate are analyzed in an effort to make recommendations for the commercial-scale collection and delivery of EFB from crude palm oil (CPO) extraction facilities to biorefineries in Malaysia. Supply chain modeling tracked inputs and outputs for financial analysis. The openLCA software was used for life cycle assessment (LCA). Allocation scenarios were used to explore the impact of accounting methodologies on the competitiveness of EFB compared to other feedstocks. Sensitivity analysis on the effect of transportation distance, emission flows, and allocation methods on resulting environmental impacts were conducted. The No Burden, Economic, and Mass allocation scenarios resulted in 17, -2.3, and -265 kg CO2-eq. BD tonne-1 EFB global warming impacts (GW), respectively. Delivered cost for EFB was calculated to be approximately 45 US$ BD tonne-1. Environmental burdens were sensitive to allocation scenario, covered area, and land use change. Delivered cost was sensitive to transport distance, covered area, and yield. It was shown that there is sufficient Malaysia EFB available for between 9 and 28 biorefineries, depending upon the scale of production.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Reeb, Carter Walker and Hays, Tyler and Venditti, Richard A. and Gonzalez, Ronalds and Kelley, Steve}, year={2014}, month={Jul}, pages={5385–5416} }
 @article{meng_moore_tilotta_kelley_park_2014, title={Toward Understanding of Bio-Oil Aging: Accelerated Aging of Bio-Oil Fractions}, volume={2}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/sc500223e}, DOI={10.1021/sc500223e}, abstractNote={Pyrolysis bio-oil from biomass is a promising intermediate for producing transportation fuels and platform chemicals. However, its instability, often called aging, has been identified as a critical hurdle that prevents bio-oil from being commercialized. The objective of this research is to explore the bio-oil aging mechanism by an accelerated aging test of fractionated bio-oil produced from loblolly pine. When water soluble (WS), ether insoluble (EIS), and pyrolytic lignin (PL) fractions were aged separately, the increased molecular weight (Mw) was observed with increasing aging temperature and the presence of acids. WS and EIS fractions had high Mw brown solids formed after aging. Adjusting the pH of WS and EIS fractions from 2.5 to 7.0 significantly reduced the tendency of a Mw increase. Similar Mw rise was also observed on a PL fraction with an elevated temperature and acid addition. Formaldehyde was found to react with the PL fraction in the presence of any acid catalysts tested, i.e., 8-fold Mw incre...}, number={8}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Meng, Jiajia and Moore, Andrew and Tilotta, David and Kelley, Stephen and Park, Sunkyu}, year={2014}, month={Jul}, pages={2011–2018} }
 @article{hoeger_filpponen_martin-sampedro_johansson_osterberg_laine_kelley_rojas_2012, title={Bicomponent Lignocellulose Thin Films to Study the Role of Surface Lignin in Cellulolytic Reactions}, volume={13}, ISSN={["1526-4602"]}, DOI={10.1021/bm301001q}, abstractNote={Ultrathin bicomponent films of cellulose and lignin derivatives were deposited on silica supports by spin coating, and after conversion into the respective polymer precursor, they were used as a model system to investigate interfacial phenomena relevant to lignocellulose biocatalysis. Film morphology, surface chemical composition, and wettability were determined by atomic force microscopy, X-ray photoelectron spectroscopy, and water contact angle, respectively. Phase separation of cellulose and lignin produced structures that resembled the cell wall of fibers and were used to monitor enzyme binding and cellulolytic reactions via quartz crystal microgravimetry. The rate and extent of hydrolysis was quantified by using kinetic models that indicated the role of the surface lignin domains in enzyme inhibition. Hydrophobic interactions between cellulases and the substrates and their critical role on irreversible adsorption were elucidated by using acetylated lignin films with different degrees of substitution. Overall, it is concluded that sensors based on the proposed ultrathin films of lignocellulose can facilitate a better understanding of the complex events that occur during bioconversion of cellulosic biomass.}, number={10}, journal={BIOMACROMOLECULES}, author={Hoeger, Ingrid C. and Filpponen, Ilari and Martin-Sampedro, Raquel and Johansson, Leena-Sisko and Osterberg, Monika and Laine, Janne and Kelley, Stephen and Rojas, Orlando J.}, year={2012}, month={Oct}, pages={3228–3240} }
 @article{treasure_gonzalez_venditti_pu_jameel_kelley_prestemon_2012, title={Co-production of electricity and ethanol, process economics of value prior combustion}, volume={62}, ISSN={0196-8904}, url={http://dx.doi.org/10.1016/j.enconman.2012.04.002}, DOI={10.1016/j.enconman.2012.04.002}, abstractNote={A process economic analysis of co-producing bioethanol and electricity (value prior to combustion) from mixed southern hardwood and southern yellow pine is presented. Bioethanol is produced by extracting carbohydrates from wood via autohydrolysis, membrane separation of byproducts, enzymatic hydrolysis of extracted oligomers and fermentation to ethanol. The residual solids after autohydrolysis are pressed and burned in a power boiler to generate steam and electricity. A base case scenario of biomass combustion to produce electricity is presented as a reference to understand the basics of bio-power generation economics. For the base case, minimum electricity revenue of $70–$96/MWh must be realized to achieve a 6–12% internal rate of return. In the alternative co-production cases, the ethanol facility is treated as a separate business entity that purchases power and steam from the biomass power plant. Minimum ethanol revenue required to achieve a 12% internal rate of return was estimated to be $0.84–$1.05/l for hardwood and $0.74–$0.85/l for softwood. Based on current market conditions and an assumed future ethanol selling price of $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.}, journal={Energy Conversion and Management}, publisher={Elsevier BV}, author={Treasure, T. and Gonzalez, R. and Venditti, R. and Pu, Y. and Jameel, H. and Kelley, S. and Prestemon, Jeffrey}, year={2012}, month={Oct}, pages={141–153} }
 @article{horvath_peszlen_gierlinger_peralta_kelley_csoka_2012, title={Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy}, volume={66}, ISSN={["1437-434X"]}, DOI={10.1515/hf-2011-0126}, abstractNote={Abstract}, number={6}, journal={HOLZFORSCHUNG}, author={Horvath, Laszlo and Peszlen, Ilona and Gierlinger, Notburga and Peralta, Perry and Kelley, Steve and Csoka, Levente}, year={2012}, month={Aug}, pages={717–725} }
 @article{hosseinaei_wang_rials_xing_taylor_kelley_2011, title={Effect of hemicellulose extraction on physical and mechanical properties and mold susceptibility of flakeboard}, volume={61}, DOI={10.13073/0015-7473-61.1.31}, abstractNote={Hemicellulose is the most hydrophilic polymer of wood, and as a polysaccharide, it has potential applications in conversion to biofuels. The objective of this study was to enhance properties of flakeboard by extracting hemicellulose. Hot-water pretreatment was performed to extract hemicellulose under different temperatures (140°C, 155°C, and 170°C) and times (30 and 60 min). The flakes were blended with 5 percent liquid phenol-formaldehyde resin and 1 percent wax emulsion. The mat was pressed at 200°C for 5 minutes. The physical and mechanical properties and the susceptibility of flakeboard to mold were studied. Panels made from the hemicellulose-extracted flakes showed remarkable decreases in water absorption and thickness swelling without a decrease in mechanical properties. Resistance of the panels to the mold growth also increased with increasing mass loss due to extraction. The most severe condition of extraction (170°C, 60 min), in addition to having the lowest water absorption a...}, number={1}, journal={Forest Products Journal}, author={Hosseinaei, O. and Wang, S. Q. and Rials, T. G. and Xing, C. and Taylor, A. M. and Kelley, Stephen}, year={2011}, pages={31–37} }
 @article{hoeger_rojas_efimenko_velev_kelley_2011, title={Ultrathin film coatings of aligned cellulose nanocrystals from a convective-shear assembly system and their surface mechanical properties}, volume={7}, ISSN={1744-683X 1744-6848}, url={http://dx.doi.org/10.1039/c0sm01113d}, DOI={10.1039/c0sm01113d}, abstractNote={Ultrathin films of aligned cellulose nanocrystals (CNCs) were deposited on solid supports by using convective and shear forces. Compared to previous systems involving high electric or magnetic fields to control the orientation of these rod-like natural nanoparticles, the proposed process of alignment was very simple, inexpensive and with potential for scale up. The effect of concentration of CNC in aqueous suspensions, type of solid support, relative humidity and rates of withdrawal of the deposition plate were determined by using atomic force microscopy (AFM) and ellipsometry. The degree of orientation was quantified from the number density of CNCs in leading angles by using image analyses. Also, the contribution of shear and capillary forces on alignment parallel and normal to the withdrawal direction was elucidated. The best alignment of CNCs in the withdrawal direction, favored by shear effects, was achieved with gold and silica supports with a pre-adsorbed cationic polyelectrolyte layer and at a CNC suspension concentration above 2.5% (w/w), below the critical concentration for chiral nematic phase separation. Compared to the bare solid support, nanoindentation of the obtained coatings of ultrathin films of oriented CNCs provided enhanced surface mechanical strength and wear resistance. A transverse Young's modulus, hardness and coefficient of friction of 8.3 ± 0.9 GPa, 0.38 ± 0.03 GPa and 0.51 ± 0.23 GPa, respectively, were measured. Notably, the transverse Young's modulus was found to be in agreement with reported values predicted by molecular modeling and measured for single CNCs by using atomic force microscopy.}, number={5}, journal={Soft Matter}, publisher={Royal Society of Chemistry (RSC)}, author={Hoeger, Ingrid and Rojas, Orlando J. and Efimenko, Kirill and Velev, Orlin D. and Kelley, Steve S.}, year={2011}, pages={1957} }
 @article{horvath_peszlen_peralta_kelley_2011, title={Use of transmittance near-infrared spectroscopy to predict the mechanical properties of 1-and 2-year-old transgenic aspen}, volume={45}, ISSN={["1432-5225"]}, DOI={10.1007/s00226-010-0330-x}, number={2}, journal={WOOD SCIENCE AND TECHNOLOGY}, author={Horvath, Laszlo and Peszlen, Ilona and Peralta, Perry and Kelley, Steve}, year={2011}, month={May}, pages={303–314} }
 @article{habibi_hoeger_kelley_rojas_2010, title={Development of Langmuir-Schaeffer Cellulose Nanocrystal Monolayers and Their Interfacial Behaviors}, volume={26}, ISSN={["0743-7463"]}, DOI={10.1021/la902444x}, abstractNote={Model cellulose surfaces based on cellulose nanocrystals (CNs) were prepared by the Langmuir-Schaeffer technique. Cellulose nanocrystals were obtained by acid hydrolysis of different natural fibers, producing rodlike nanoparticles with differences in charge density, aspect ratio, and crystallinity. Dioctadecyldimethylammonium bromide (DODA-Br) cationic surfactant was used to create CN-DODA complexes that allowed transfer of the CNs from the air/liquid interface in an aqueous suspension to hydrophobic solid substrates. Langmuir-Schaeffer horizontal deposition at various surface pressures was employed to carry out such particle transfer that resulted in CN monolayers coating the substrate. The morphology and chemical composition of the CN films were characterized by using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Also, their swelling behavior and stability after treatment with aqueous and alkaline solutions were studied using quartz crystal microgravimetry (QCM). Overall, it is concluded that the Langmuir-Schaeffer method can be used to produce single coating layers of CNs that were shown to be smooth, stable, and strongly attached to the solid support. The packing density of the films was controlled by selecting the right combination of surface pressure during transfer to the solid substrate and the amount of CNs available relative to the cationic charges at the interface.}, number={2}, journal={LANGMUIR}, author={Habibi, Youssef and Hoeger, Ingrid and Kelley, Stephen S. and Rojas, Orlando J.}, year={2010}, month={Jan}, pages={990–1001} }
 @article{arantes_qian_kelley_milagres_filley_jellison_goodell_2009, title={Biomimetic oxidative treatment of spruce wood studied by pyrolysis-molecular beam mass spectrometry coupled with multivariate analysis and C-13-labeled tetramethylammonium hydroxide thermochemolysis: implications for fungal degradation of wood}, volume={14}, ISSN={["1432-1327"]}, DOI={10.1007/s00775-009-0569-6}, abstractNote={In this work, pyrolysis-molecular beam mass spectrometry analysis coupled with principal components analysis and (13)C-labeled tetramethylammonium hydroxide thermochemolysis were used to study lignin oxidation, depolymerization, and demethylation of spruce wood treated by biomimetic oxidative systems. Neat Fenton and chelator-mediated Fenton reaction (CMFR) systems as well as cellulosic enzyme treatments were used to mimic the nonenzymatic process involved in wood brown-rot biodegradation. The results suggest that compared with enzymatic processes, Fenton-based treatment more readily opens the structure of the lignocellulosic matrix, freeing cellulose fibrils from the matrix. The results demonstrate that, under the current treatment conditions, Fenton and CMFR treatment cause limited demethoxylation of lignin in the insoluble wood residue. However, analysis of a water-extractable fraction revealed considerable soluble lignin residue structures that had undergone side chain oxidation as well as demethoxylation upon CMFR treatment. This research has implications for our understanding of nonenzymatic degradation of wood and the diffusion of CMFR agents in the wood cell wall during fungal degradation processes.}, number={8}, journal={JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY}, author={Arantes, Valdeir and Qian, Yuhui and Kelley, Stephen S. and Milagres, Adriane M. F. and Filley, Timothy R. and Jellison, Jody and Goodell, Barry}, year={2009}, month={Nov}, pages={1253–1263} }
 @article{lindblad_keyes_gedvilas_rials_kelley_2008, title={FTIR imaging coupled with multivariate analysis for study of initial diffusion of different solvents in cellulose acetate butyrate films}, volume={15}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-007-9173-5}, number={1}, journal={CELLULOSE}, author={Lindblad, Margaretha Soederqvist and Keyes, Brian M. and Gedvilas, Lynn M. and Rials, Timothy G. and Kelley, Stephen S.}, year={2008}, month={Feb}, pages={23–33} }
 @article{labbe_andre_rials_kelley_2008, title={Two-dimensional homo- and hetero-correlation technique applied to NIR and py-MBMS spectra of wood}, volume={62}, DOI={10.1515/HF2008.039}, number={2}, journal={Holzforschung}, author={Labbe, N. and Andre, N. and Rials, T. G. and Kelley, Stephen}, year={2008}, pages={176–182} }
 @article{hedrick_bennett_rials_kelley_2007, title={Correlation of near-infrared spectroscopy measurements with the properties of treated wood}, volume={19}, DOI={10.1061/(ASCE)0899-1561(2007)19:4(279)}, abstractNote={Near-infrared (NIR) spectroscopy was used to predict the longitudinal tensile modulus, the longitudinal tensile strength, and the creosote content of wood from an out-of-service southern pine utility pole. Tensile samples were cut from the pole in the radial direction and near-infrared spectra were obtained before testing. Coefficients of determination r2 , of 0.80–0.86 were obtained between the NIR spectra predicted modulus and measured modulus. Coefficients of determination for strength were lower, 0.58–0.63. After tensile testing, the specimens were ground in a mill and spectra were obtained from the homogeneous ground samples. There was a slight decrease in the coefficients of determination using the ground samples, 0.76–0.82 for the modulus and 0.46–0.57 for the strength. Creosote content was difficult to predict with the NIR spectra of the whole sample, but coefficients of determination >0.9 were obtained with the ground samples. There was little difference in the results for spectra collected over ...}, number={4}, journal={Journal of Materials in Civil Engineering}, author={Hedrick, S. E. and Bennett, R. M. and Rials, T. G. and Kelley, Stephen}, year={2007}, pages={279–285} }
 @inproceedings{labbe_rials_kelley_martin_2007, title={High-throughput material characterization techniques: near infrared and laser-induced breakdown spectroscopy}, ISBN={0841239819}, DOI={10.1021/bk-2007-0954.ch031}, abstractNote={High throughput technologies such as near infrared, mid infrared and laser induced breakdown spectroscopy are very powerful techniques that can be used to characterize heterogeneous materials. They have been developed in various fields to investigate properties and processes and to control the quality of manufactured products. This chapter gives a brief description of these technologies and some examples of their applications in the forest industry. Rapid methods to measure chemical composition and properties of materials and manufactured products are indispensable to control their quality and to optimize their processes. Analytical spectroscopy such as near infrared, mid infrared and laser induced breakdown spectroscopy are useful methods that can be developed as high throughput technologies and can be implemented as quality and process control tools in an industrial environment. These methods become outstandingly effective when coupled with statistic analysis to classify materials and predict their properties.}, booktitle={ACS Symposium Series 954, (Materials, Chemicals, and Energy from Forest Biomass)}, author={Labbe, N. and Rials, T. G. and Kelley, Stephen and Martin, M. Z.}, year={2007}, pages={495–512} }
 @inproceedings{kelley_2007, title={Lignocellulosic biorefineries: reality, hype, or something in between?}, ISBN={0841239819}, DOI={10.1021/bk-2007-0954.ch002}, abstractNote={With growing concerns over increasing fuel prices, green house gas emissions and the national security issues surrounding reliance on imported oil, there is an increasing interest in technologies that allow for sustainable production of energy and fuels from domestic resources. Among the various renewable energy options, lignocellulosic biomass is unique in its ability to produce liquid transportation fuels, which can be integrated into the current fuel infrastructure. There are a wide variety of technologies that can be used to convert lignocellulosic biomass into liquid fuels, including fermentation of sugars and production of liquid fuels from biomass derived syngas. There are also two industries with well-developed biomass conversion infrastructure, the corn ethanol industry, and the pulp and paper industry, that could be used as a launch point for developing lignocellulosic biorefineries. These industries offer opportunities for 1) producing monomeric sugars from biomass residues that can be fermented into ethanol, and 2) additional opportunities for converting the lignin-rich fermentation residues and low quality biomass residues to syngas that can be used to produce liquid fuels. The pulp and paper industry offers opportunities for 3) extracting fermentable sugars prior to pulping and converting these sugars to ethanol, and 4) gasifying the biomass or lignin-rich spent pulping liquors for the production of liquid fuels. Finally, there are attractive technologies being developed for the direct conversion of biomass-derived oils into transportation fuels in petroleum refineries. In all of these technology areas there have been significant advances, but there is still a need for additional technology development to overcome economic challenges. There is also a need for a better understanding of the energy and environmental benefits of these lignocellulosic biorefineries. This paper will highlight the technical challenges to be overcome, and potential for producing fuel products from lignocellulosic biomass.}, booktitle={ACS Symposium Series 954, (Materials, Chemicals, and Energy from Forest Biomass)}, author={Kelley, Stephen}, year={2007}, pages={31–47} }
 @article{tze_wang_rials_pharr_kelley_2007, title={Nanoindentation of wood cell walls: Continuous stiffness and hardness measurements}, volume={38}, ISSN={["1878-5840"]}, DOI={10.1016/j.compositesa.2006.06.018}, abstractNote={The objective of this study was to measure the mechanical properties of individual, native wood fibers using the continuous nanoindentation measurement technique. The indentation depth profile exhibited a small length-scale effect, which was confirmed using the size-effect index derived from the indentation loading curve. The hardness (Hu) or stiffness (Eu) values determined from indentation unloading were also examined for 10 different annual rings of a loblolly pine, with microfibril angles (MFA) between 14° and 36°. A predictable pattern of Eu values was found as a function of MFA, and hence Eu can at least be considered a relative measure of the longitudinal stiffness properties of wood cell walls. For Hu values, a dependence on orientation was observed, and there is a preliminary indication that the dependence could be affected by cell-wall extractives. It is thus desirable, for cell-wall modification studies, to minimize any unintended variations by using samples that are from the same growth ring, so that any treatment-induced changes in the cell-wall hardness can be identified.}, number={3}, journal={COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING}, author={Tze, W. T. Y. and Wang, S. and Rials, T. G. and Pharr, G. M. and Kelley, S. S.}, year={2007}, pages={945–953} }
 @article{khare_greenberg_kelley_pilath_roh_tyber_2007, title={Synthesis and characterization of dense and porous cellulose films}, volume={105}, ISSN={["1097-4628"]}, DOI={10.1002/app.25888}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Khare, Vivek P. and Greenberg, Alan R. and Kelley, Stephen S. and Pilath, Heidi and Roh, Il Juhn and Tyber, Jeff}, year={2007}, month={Aug}, pages={1228–1236} }
 @misc{schultz_nicholas_kelley_2007, title={nonleachable composition and method to use}, volume={WO/2007/109735}, number={2007}, publisher={Geneva: World Intellectual Property Organization (WIPO)}, author={Schultz, T. P. and Nicholas, D. D. and Kelley, S. S.}, year={2007} }
 @article{kent_leichti_morrell_rosowsky_kelley_2006, title={Analytical tools to predict changes in properties of oriented strandboard exposed to the fungus Postia placenta}, volume={60}, ISSN={["1437-434X"]}, DOI={10.1515/HF.2006.053}, abstractNote={Abstract}, number={3}, journal={HOLZFORSCHUNG}, author={Kent, Scott M. and Leichti, Robert J. and Morrell, Jeffrey J. and Rosowsky, David V. and Kelley, Stephen S.}, year={2006}, pages={332–338} }
 @article{andre_labbe_rials_kelley_2006, title={Assessment of wood load condition by near infrared (NIR) spectroscopy}, volume={41}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-006-4433-6}, number={7}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Andre, N and Labbe, N and Rials, T and Kelley, S}, year={2006}, month={Apr}, pages={1879–1886} }
 @article{labbe_rials_kelley_2006, title={FTIR Imaging of wood and wood composites}, ISBN={["0-8138-0439-6"]}, DOI={10.1002/9780470999714.ch9}, abstractNote={This chapter contains section titled: Abstract Introduction Experimental approach Results and discussion Application Acknowledgments}, journal={CHARACTERIZATION OF THE CELLULOSIC CELL WALL}, author={Labbe, Nicole and Rials, Timothy G. and Kelley, Stephen S.}, year={2006}, pages={110-+} }
 @article{labbe_rials_kelley_cheng_kim_li_2005, title={FT-IR imaging and pyrolysis-molecular beam mass spectrometry: new tools to investigate wood tissues}, volume={39}, ISSN={["1432-5225"]}, DOI={10.1007/s00226-004-0274-0}, number={1}, journal={WOOD SCIENCE AND TECHNOLOGY}, author={Labbe, N and Rials, TG and Kelley, SS and Cheng, ZM and Kim, JY and Li, Y}, year={2005}, month={Mar}, pages={61–U19} }
 @misc{petersen_viviani_magrini-bair_kelley_moens_shepherd_dubois_2005, title={Nongovernmental valorization of carbon dioxide}, volume={338}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2004.06.025}, abstractNote={Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described.}, number={3}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Petersen, G and Viviani, D and Magrini-Bair, K and Kelley, S and Moens, L and Shepherd, P and DuBois, D}, year={2005}, month={Feb}, pages={159–182} }
 @article{gaibler_rochefort_wilson_kelley_2004, title={Blends of cellulose ester/phenolic polymers - chemical and thermal properties of blends with polyvinyl phenol}, volume={11}, ISSN={["0969-0239"]}, DOI={10.1023/B:CELL.0000025425.00668.de}, number={2}, journal={CELLULOSE}, author={Gaibler, DW and Rochefort, WE and Wilson, JB and Kelley, SS}, year={2004}, month={Jun}, pages={225–237} }
 @inproceedings{hedrick_bennett_kelley_rials_2004, title={Determination of Wood Properties Using Near Infrared Sprectroscopy}, ISBN={9780784407004}, url={http://dx.doi.org/10.1061/40700(2004)64}, DOI={10.1061/40700(2004)64}, abstractNote={This study investigates the use of Near Infrared (NIR) spectroscopy as a nondestructive means of determining wood properties. The parallel to the grain modulus of elasticity was predicted from the near infrared spectra and compared to the modulus of elasticity obtained from tensile tests. Analysis was also performed to determine if NIR spectroscopy is a viable means to determine in situ properties of wood using hand-held spectrometers that have a smaller spectra range. The hand held spectrometers were modeled by using reduced NIR spectra in order to determine the modulus of elasticity. The re sults demonstrated that NIR spectroscopy has excellent correlation (r = 0.93) to the modulus of elasticity. The reduced NIR spectra also had a good correlation (r = 0.90) thus making Near Infrared spectroscopy a feasible, nondestructive technique to deter mine wood properties.}, booktitle={Structures 2004}, publisher={American Society of Civil Engineers}, author={Hedrick, Stephen E. and Bennett, Richard M. and Kelley, Stephen S. and Rials, Timothy G.}, year={2004}, month={May} }
 @article{volkov_fadeev_khotimsky_litvinova_selinskaya_mcmillan_kelley_2004, title={Effects of synthesis conditions on the pervaporation properties of poly[1-(trimethylsilyl)-1-propyne] useful for membrane bioreactors}, volume={91}, ISSN={["0021-8995"]}, DOI={10.1002/app.13358}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Volkov, VV and Fadeev, AG and Khotimsky, VS and Litvinova, EG and Selinskaya, YA and McMillan, JD and Kelley, SS}, year={2004}, month={Feb}, pages={2271–2277} }
 @article{cornish_myers_kelley_2004, title={Latex quantification in homogenate and purified latex samples from various plant species using near infrared reflectance spectroscopy}, volume={19}, ISSN={["1872-633X"]}, DOI={10.1016/j.indcrop.2003.10.009}, abstractNote={Parthenium argentatum (guayule) is under commercial development as a source of hypoallergenic latex, which is suitable for the manufacture of latex medical devices safe for use by people suffering from Type I latex protein allergy. Improving agronomic practices, post-harvest shrub handling, and optimizing latex extraction and purification protocols during bioprocessing are hampered by the relatively cumbersome latex quantification methods currently employed. Current methods require several hours before analytical results can be obtained. The object of our study was to develop and test a near infrared (NIR) spectroscopic method for rapid quantification of latex in both wet and dried P. argentatum homogenate and purified latex samples. The procedure was tested on latex samples from Ficus elastica (Indian rubber tree), Helianthus annuus (sunflower), Hevea brasiliensis (Brazilian or para rubber tree) and Taraxacum kok-saghyz (Russian dandelion). P. argentatum latex could be accurately quantified, over a wide concentration range of 0 to 25 mg/ml. The correlations between the measured rubber content and the rubber content predicted by NIR were 0.96 and 0.91 for dry and wet samples, respectively. The presence of homogenate components unrelated to the latex fraction did not perturb the correlations obtained. Similar predictive models could be used to measure the rubber content in F. elastica, H. annuus, H. brasilensis and T. kok-saghyz.}, number={3}, journal={INDUSTRIAL CROPS AND PRODUCTS}, author={Cornish, K and Myers, MD and Kelley, SS}, year={2004}, month={May}, pages={283–296} }
 @article{kelley_rowell_davis_jurich_ibach_2004, title={Measuring the chemical composition of agricultural fibers with near infrared spectroscopy and pyrolysis molecular beam mass spectrometry}, volume={27}, DOI={10.1016/j.biomboie.2003.11.005}, journal={Biomass and Bioenergy}, author={Kelley, Stephen and Rowell, R. M. and Davis, M. and Jurich, C. K. and Ibach, R.}, year={2004}, pages={77–88} }
 @article{so_via_groom_schimleck_shupe_kelley_rials_2004, title={Near infrared spectroscopy in the forest products industry}, volume={54}, number={3}, journal={Forest Products Journal}, author={So, C-L and Via, B. K. and Groom, L. H. and Schimleck, L. R. and Shupe, T. F. and Kelley, S. S. and Rials, T. G.}, year={2004}, pages={6–11} }
 @article{kelley_rowell_davis_jurich_ibach_2004, title={Rapid analysis of the chemical composition of agricultural fibers using near infrared spectroscopy and pyrolysis molecular beam mass spectrometry}, volume={27}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2003.11.005}, DOI={10.1016/j.biombioe.2003.11.005}, abstractNote={The chemical composition of a variety of agricultural biomass samples was analyzed with near infrared spectroscopy and pyrolysis molecular beam mass spectroscopy. These samples were selected from a wide array of agricultural residue samples and included residues that had been subjected to a variety of different treatments including solvent extractions and chemical modifications. This analysis showed that both spectroscopic tools, coupled with multivariate analytical techniques, could be used to differentiate the samples and accurately predict the chemical composition of this disparate set of agricultural biomass samples.}, number={1}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Kelley, S and Rowell, R and Davis, M and Jurich, C and Ibach, R}, year={2004}, month={Jul}, pages={77–88} }
 @article{kelley_rials_snell_groom_sluiter_2004, title={Use of near infrared spectroscopy to measure the chemical and mechanical properties of solid wood}, volume={38}, ISSN={["1432-5225"]}, DOI={10.1007/s00226-003-0213-5}, number={4}, journal={WOOD SCIENCE AND TECHNOLOGY}, author={Kelley, SS and Rials, TG and Snell, R and Groom, LH and Sluiter, A}, year={2004}, month={Jul}, pages={257–276} }
 @article{kelley_rials_groom_so_2004, title={Use of near infrared spectroscopy to predict the mechanical properties of six softwoods}, volume={58}, ISSN={["0018-3830"]}, DOI={10.1515/HF.2004.039}, abstractNote={Abstract}, number={3}, journal={HOLZFORSCHUNG}, author={Kelley, SS and Rials, TG and Groom, LR and So, CL}, year={2004}, pages={252–260} }
 @article{fadeev_kelley_mcmillan_selinskaya_khotimsky_volkov_2003, title={Effect of yeast fermentation by-products on poly[1-(trimethylsilyl)-1-propyne] pervaporative performance}, volume={214}, ISSN={["0376-7388"]}, DOI={10.1016/S0376-7388(02)00550-1}, abstractNote={The pervaporation recovery of ethanol from yeast fermentation broth was investigated using poly[1-(trimethylsilyl)-1-propyne]. The deterioration of membrane performance in the presence of fermentation broth was observed. The fouled membrane was characterized by gas permeation and density measurements, and sorption of pure components of the fermentation broth in PTMSP was studied to clarify the fouling mechanism. It was concluded that properties of the membrane deteriorate due to internal contamination of the PTMSP free volume with non-volatile by-products of the fermentation. The PTMSP film did not show appreciable deterioration of membrane properties in the pervaporation of aqueous solution of organic compounds with high volatility.}, number={2}, journal={JOURNAL OF MEMBRANE SCIENCE}, author={Fadeev, AG and Kelley, SS and McMillan, JD and Selinskaya, YA and Khotimsky, VS and Volkov, VV}, year={2003}, month={Apr}, pages={229–238} }
 @misc{meglen_kelley_2003, title={Method for predicting dry mechanical properties from wet wood and standing trees}, volume={6,606,568}, number={2003 Feb. 25}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Meglen, R. R. and Kelley, S. S.}, year={2003} }
 @misc{kelley_2003, title={Method of predicting mechanical properties of decayed wood}, volume={6,593,572}, number={2003 Jul. 15}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Kelley, S. S.}, year={2003} }
 @misc{meglen_kelley_2003, title={Use of a region of the visible and near infrared spectrum to predict mechanical properties of wet wood and standing trees}, volume={6,525,319}, number={2003 Aug. 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Meglen, R. R. and Kelley, S. S.}, year={2003} }
 @article{kelley_filley_greenberg_peterson_krantz_2002, title={Chemical modification of cellulose acetate with titanium isopropoxide}, volume={7}, ISSN={["1023-666X"]}, DOI={10.1080/10236660214595}, abstractNote={This study describes the chemical modification of cellulose acetate (CA) using titanium isopropoxide (TiP) in a sol-gel process for the formation of an organic/inorganic hybrid (OIH) material. The hydrolysis and condensation reactions that characterize this process result in CA cross-linking and formation of inorganic oxide particles. TiP-modified CA gels and membrane materials are characterized by solubility and swelling measurements, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry (DSC) and ultrasonic time-domain reflectometry. Whereas the solubility of the CA significantly decreased with increasing TiP exposure consistent with high levels of cross-linking, unambiguous spectroscopic evidence for cross-linking could not be determined. In addition, DSC measurements indicated no significant change in CA glass-transition temperature as a function of TiP exposure. On the other hand, TiP treatment dramatically improved the creep behavior of treated porous CA membranes, whereby the total compressive strain decreases by as much as 70% relative to the untreated materials. Overall, the results suggest that TiP treatment can be used as a post-fabrication processing step to create OIH-modified CA membranes with improved chemical and mechanical stability.}, number={1-2}, journal={INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION}, author={Kelley, SS and Filley, J and Greenberg, AR and Peterson, R and Krantz, WB}, year={2002}, pages={162–180} }
 @inproceedings{kelley_davis_looker_2002, title={Rapid analysis tools for measuring the chemical composition of biomass}, booktitle={Proceedings of The Sixth Pacific Rim Bio-Based Composites Symposium}, author={Kelley, S. S. and Davis, M. F. and Looker, M. J.}, year={2002} }
 @inproceedings{rials_kelley_groom_r._so_2002, title={Rapid assessment of softwood properties with near infrared spectroscopy}, booktitle={Proceedings of The Sixth Pacific Rim Bio-Based Composites Symposium}, author={Rials, T. G. and Kelley, S. S. and Groom, L. H. Snell and R. and So, C-L}, year={2002} }
 @inproceedings{so_groom_rials_snell_kelley_meglen_2002, title={Rapid assessment of the fundamental property variation of wood}, volume={11}, booktitle={Proceedings of the 11th Biennial Southern Silvicultural Research Conference}, publisher={Ashville, NC: USDA Forest Serivice Southern Research Station}, author={So, C-L and Groom, L. H. and Rials, T. G. and Snell, R. and Kelley, S. S. and Meglen, R. R.}, year={2002}, pages={176–180} }
 @article{alma_kelley_2002, title={The application of pyrolysis molecular beam mass spectrometry for characterization of bark phenolysis products}, volume={22}, DOI={10.1016/s0961-9534(02)00018-1}, abstractNote={Barks from four common Mediterranean trees subjected to phenolysis under acidic conditions at moderate temperature (130°C or 150°C) were evaluated with pyrolysis-molecular beam mass spectrometer (py-MBMS). The results indicated that both concentration of acid catalyst and the phenolysis temperature have an impact on the chemical composition of both the isolated oils and the solid residue, with the acid concentration having the greatest influence. The primary phenolysis reaction products included phenolics and furans. As expected, at higher acid concentrations the phenolysis products contained less carbohydrate and included more phenolic fragments. These phenolysis oils should be useful as feedstocks for the production of phenol formaldehyde resins. The py-MBMS method was found to be an effective and convenient method to understand bark phenolysis.}, journal={Biomass and Bioenergy}, author={Alma, M. H. and Kelley, Stephen}, year={2002}, pages={411–419} }
 @article{kelley_jellison_goodell_2002, title={Use of NIR and pyrolysis-MBMS coupled with multivariate analysis for detecting the chemical changes associated with brown-rot biodegradation of spruce wood}, volume={209}, ISSN={["1574-6968"]}, DOI={10.1111/j.1574-6968.2002.tb11117.x}, abstractNote={Near infrared (NIR) spectroscopy and pyrolysis-molecular beam mass spectrometry (py-MBMS) analysis can be used in conjunction with multivariate regression and principal components analysis to differentiate brown-rot-degraded wood from non-degraded spruce and to follow the temporal changes in wood undergoing brown-rot degradation. Regression of NIR test results vs. percent weight loss for Postia placenta- and Gloeophyllum trabeum-infected spruce wood blocks yielded a correlation coefficient of 0.96. Regression of MBMS test results for the same samples yielded a correlation coefficient of 0.96. Principle components analysis was used to differentiate non-infected wood and P. placenta- and G. trabeum-infected wood. These techniques may be used to detect different types of biodegradation and to develop a better understanding of the chemical changes that the wood undergoes when it is subjected to brown-rot biodegradation.}, number={1}, journal={FEMS MICROBIOLOGY LETTERS}, author={Kelley, SS and Jellison, J and Goodell, B}, year={2002}, month={Mar}, pages={107–111} }
 @misc{meglen_kelley_2002, title={Use of a region of the visible and near infrared spectrum to predict mechanical properties of wet wood and standing trees}, volume={WO/2002/01200}, number={2002}, publisher={Geneva: World Intellectual Property Organization (WIPO)}, author={Meglen, R. R. and Kelley, S. S.}, year={2002} }
 @article{rials_kelley_so_2002, title={Use of advanced spectroscopic techniques for predicting the mechanical properties of wood composites}, volume={34}, number={3}, journal={Wood and Fiber Science}, author={Rials, T. G. and Kelley, S. S. and So, C-L}, year={2002}, pages={398–407} }
 @inproceedings{rocha_chum_kelley_2001, title={Bio-oils as a s source of phenolics for production of resol wood resins}, booktitle={Brazilian Symposium on the Chemistry of Lignins and Other Wood Components, 6th Proceeding}, author={Rocha, R. L. and Chum, H. L. and Kelley, S. S.}, editor={F. T. Silva, A. Ferraz and Paiva, T. C. B.Editors}, year={2001}, pages={40–44} }
 @article{fadeev_selinskaya_kelley_meagher_litinova_khotimsky_v._volkov_2001, title={Extraction of butanol from aqueous solutions by pervaporation through poly(1-trimethylsilyl-1-propyne)}, volume={186}, ISSN={["0376-7388"]}, DOI={10.1016/S0376-7388(00)00683-9}, abstractNote={Poly(1-trimethylsilyl-1-propyne) (PTMSP) was synthesized using a TaCl5–Al(i-Bu)3 catalysis system. Pervaporation and sorption of n-butanol–water mixtures were studied, and the peculiarities of water and butanol co-permeation are discussed. The strong dependence of water partial flux (with a minimum at 1 wt.% butanol in feed) on butanol concentration in feed was observed. S-shaped isotherms of butanol and total sorption were found for PTMSP in 0–1 wt.% concentration range. It appears that blocking of PTMSP nanopores by high sorbing organic molecules controls the pervaporation of butanol from dilute aqueous solutions. Data are discussed in regard with PTMSP morphology.}, number={2}, journal={JOURNAL OF MEMBRANE SCIENCE}, author={Fadeev, A. G. and Selinskaya, Ya A. and Kelley, Stephen and Meagher, M. M. and Litinova, E. and Khotimsky, G. and V., S. and Volkov, V. V.}, year={2001}, month={May}, pages={205–217} }
 @article{sugama_kelley_gawlik_2001, title={Hydrothermal degradation study of phenolic polymer coatings by advanced analytical methods}, volume={73}, ISSN={["0361-8773"]}, DOI={10.1007/BF02698399}, number={917}, journal={JOURNAL OF COATINGS TECHNOLOGY}, author={Sugama, T and Kelley, SS and Gawlik, K}, year={2001}, month={Jun}, pages={65–71} }
 @inproceedings{wang_davis_myers_kelley_2001, title={Influence of the reactivity and functionality of phenolic model compounds on network formation reactions}, ISBN={0841237271}, booktitle={Chemicals and Materials from Renewable Resources (ACS Symposium Series 784)}, author={Wang, X-M and Davis, M. F. and Myers, M. D. and Kelley, S. S.}, year={2001}, pages={174–190} }
 @article{reinsch_greenberg_kelley_2000, title={A new technique for the simultaneous, real-time measurement of membrane compaction and performance during exposure to high-pressure gas}, volume={171}, DOI={10.1016/S0376-7388(00)00307-0}, abstractNote={Membrane compaction accounts for a major source of the flux decline that occurs during gas separation using polymeric membranes. Previous membrane compaction studies have been limited by the inability to simultaneously measure membrane performance. In this study, we report the development of a technique based on ultrasonic time-domain reflectometry (TDR) that enables the simultaneous, real-time, noninvasive measurement of membrane compaction and performance during gas separation. In order to demonstrate the utility of the technique, representative data are presented for membrane compaction and pressure-normalized flux of a commercial asymmetric cellulose acetate (CA) gas separation membrane. Data obtained during the recovery cycle, i.e., after the pressure difference across the membrane is removed, are also described. These preliminary results indicate that the ultrasonic TDR technique can be successfully applied to quantify the effect of high-pressure gases on polymeric films and asymmetric membranes.}, number={2}, journal={Journal of Membrane Science}, author={Reinsch, V. E. and Greenberg, A. G. and Kelley, Stephen}, year={2000}, pages={217–228} }
 @article{fadeev_meagher_kelley_volkov_2000, title={Fouling of poly[-1-(trimethylsilyl)-1-propyne] membranes in pervaporative recovery of butanol from aqueous solutions and ABE fermentation broth}, volume={173}, ISSN={["0376-7388"]}, DOI={10.1016/S0376-7388(00)00359-8}, abstractNote={Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) dense films were evaluated for n-butanol recovery from aqueous solutions and acetone–butanol–ethanol (ABE) fermentation broth. Flux decline through PTMSP dense films due to polymer compaction under vacuum conditions, relaxation in alcohol and alcohol/water mixtures, and membrane contamination are discussed. Flux decline of a PTMSP film during pervaporation of 20 g/l BuOH/water mixture was fitted to the following function, y=At−b. PTMSP films change their geometry when exposed to alcohol and alcohol/water mixtures and then dried. As a result of the relaxation process, polymer film becomes thicker and denser, effecting membrane performance. PTMSP films that were treated with 70% iso-propanol/water show linear flux decline versus pervaporation time. Strong lipid adsorption seems to occur on the membrane surface when fermentation broth is used as a feed causing flux decline within short period of time.}, number={1}, journal={JOURNAL OF MEMBRANE SCIENCE}, author={Fadeev, AG and Meagher, MM and Kelley, SS and Volkov, VV}, year={2000}, month={Jul}, pages={133–144} }
 @article{alma_kelley_bektas_2000, title={The tensile properties of molding products obtained by the condensation of various tree barks and phenol by using sulfuric acid as a catalyst}, volume={19}, ISSN={["0261-8028"]}, DOI={10.1023/A:1006704501712}, number={17}, journal={JOURNAL OF MATERIALS SCIENCE LETTERS}, author={Alma, MH and Kelley, SS and Bektas, I}, year={2000}, month={Sep}, pages={1517–1520} }
 @article{alma_kelley_2000, title={The thermal stability of novolac-type thermosets made by the condensation of bark and phenol}, volume={68}, DOI={10.1016/s0141-3910(00)00029-x}, abstractNote={The barks of calabrian pine (Pinus brutia) and Anatolia chestnut (Cestanea sativa) tree species have been condensed with phenol in the presence of sulfuric acid as a catalyst at a temperature of 130°C for 1 h. The phenolated bark species obtained was cured with hexamethylenetetramine (HMTA) at 190°C for 5 min and then, some thermal properties [thermogravimetric weight changes and glass transition point (Tg)] of the cured phenolated barks were investigated by using thermal gravimetric analysis (TGA) and differential scanning calorimetric (DSC) methods as a function of the catalyst concentrations. The results showed that themogravimetric weight losses and glass transition points (Tg) of the cured phenolated bark decreased with increasing catalyst concentration. The thermogravimetric weight loss of the cured phenolated barks was found to be comparable to those of cured commercial novolak resin and phenolated wood. Furthermore, the Tgs of the phenolated bark samples were found to increase with increasing catalyst concentration and to be obviously lower than those of commercial novolak resin.}, journal={Polymer Degradation and Stability}, author={Alma, M. H. and Kelley, Stephen}, year={2000}, pages={413} }
 @inproceedings{rocha_kelley_chum_1999, title={Application of the slow pyrolysis eucalyptus oil to make PF resins}, volume={1}, ISBN={0080430198}, booktitle={Biomass: A Growth Opportunity in Green Energy and Value-Added Products; Proceedings of the Fourth Biomass Conference of the Americas}, publisher={Oakland, California: Elsevier Science, Ltd.; United Kingdom}, author={Rocha, J. D. and Kelley, S. S. and Chum, H. L.}, editor={Overend, R. P. and Chornet, E.Editors}, year={1999}, pages={513–519} }
 @misc{gawlik_kelley_sugama_webster_reams_1999, title={Field testing of heat exchanger tube coatings}, volume={23}, journal={Geothermal resources council transactions}, author={Gawlik, K. and Kelley, S. and Sugama, T. and Webster, R. and Reams, W.}, year={1999}, pages={65–69} }
 @inproceedings{davis_wang_myers_iwamiya_kelley_1998, title={A study of the molecular interactions occurring in blends of cellulose esters and phenolic polymers}, booktitle={ACS Symposium Series 688, Cellulose Derivatives}, author={Davis, M. F. and Wang, X-M and Myers, M. D. and Iwamiya, J. H. and Kelley, S. S.}, editor={T. J. Heinze and Glasser, W. G.Editors}, year={1998}, pages={283} }
 @inproceedings{glasser_rials_kelley_dave_1998, title={The Studies of the molecular interactions between cellulose and lignin as a model for the hierarchical structure of wood}, DOI={10.1021/bk-1998-0688.ch019}, abstractNote={Wood and dietary fiber products all belong to a class of biomolecular composites that are rich in cellulose and lignin. The interaction between cellulose and lignin determines such properties as mechanical strength (wood); creep, durability and aging; cellulose purity (pulp); and digestibility (nutrients). The understanding of the interaction between cellulose and lignin can be approached from various types of analyses involving the natural biocomposites, or it can be explored by studying the physical mixtures of the two types of macromolecule s. The latter can be prepared by mixing the respective polymers in solid, solution or melt form within the constraints of solubility and melt-flowability. Such mixtures have been examined, and the results suggest that cellulose and its derivatives form two distinct phases with lignin and its derivatives; a crystalline polysaccharide-phase and a continuous amorphous phase that provides evidence for strong intermolecular interaction between the two components. In addition, results suggest that lignin and/or its derivatives are capable of contributing to the supermolecular organization of cellulose (derivatives). The interaction between lignin and cellulose varies in relation to chemical differences as well as molecular parameters. The results are consistent with the view that the hierarchical structure of the natural biocomposite wood is not only the consequence of a sequence of biochemical events, but}, booktitle={ACS Symposium Series 688, Cellulose Derivatives}, author={Glasser, W. G. and Rials, T. G. and Kelley, Stephen and Dave, V.}, editor={T. J. Heinze and Glasser, W. G.Editors}, year={1998}, pages={265} }
 @article{wag_frederick_dayton_kelley_1997, title={Characterization of black liquor char gasification using thermogravimetry and molecular beam mass spectrometry}, volume={315}, journal={AIChE Journal}, author={Wag, K. J. and Frederick, W. J. and Dayton, D. C. and Kelley, S. S.}, year={1997}, pages={67–76} }
 @article{reinsch_kelley_1997, title={Crystallization of poly(hydroxybutyrate-co-hydroxyvalerate) in wood fiber reinforced composites}, volume={64}, DOI={10.1002/(sici)1097-4628(19970531)64:9<1785::aid-app15>3.3.co;2-z}, journal={Journal of Applied Polymer Science}, author={Reinsch, V. E. and Kelley, Stephen}, year={1997}, pages={1785–1796} }
 @inproceedings{kelley_wang_myers_johnson_chum_1997, title={Effect of molecular structure on the properties of biomass oil-modified phenol formaldehyde resins}, booktitle={Proceedings of the International Symposium of Wood Pulp Chemistry}, author={Kelley, S. S. and Wang, X-M and Myers, M. F. and Johnson, D. K. and Chum, H. L.}, year={1997} }
 @inbook{jorgensen_pern_kelley_czanderna_schissel_1997, title={Polymers for solar energy devices}, booktitle={Functional polymers for emerging technology}, publisher={Washington, DC: American Chemical Society}, author={Jorgensen, G. and Pern, J. and Kelley, S. and Czanderna, A. and Schissel, P.}, year={1997}, pages={567–588} }
 @article{kelley_elam_evans_looker_1997, title={Recovery of phenolic monomers from industrial novolac plastics}, volume={Fall}, journal={ACS Division of Fuel Chemistry}, author={Kelley, S. S. and Elam, C. C. and Evans, R. J. and Looker, M. J.}, year={1997} }
 @article{tobiason_kelley_midland_hemingway_1997, title={Temperature dependence of (+)-catechin pyran ring proton coupling constants as measured by NMR and modeled using GMMX search methodology}, volume={38}, ISSN={["1873-3581"]}, DOI={10.1016/S0040-4039(96)02505-1}, abstractNote={Abstract The pyran ring proton coupling constants for (+)-catechin have been experimentally determined in deuterated methanol over a temperature range of 213 K to 313 K. The experimental coupling constants were simulated to 0.04 Hz on the average at a 90% confidence limit using a LAOCOON method. The temperature dependence of the coupling constants was reproduced from the Boltzmann distribution of the conformational ensemble generated by the GMMX searching program.}, number={6}, journal={TETRAHEDRON LETTERS}, author={Tobiason, FL and Kelley, SS and Midland, MM and Hemingway, RW}, year={1997}, month={Feb}, pages={985–988} }
 @article{volkov_khotimsky_gokzshaev_litvinova_fadeev_kelley_1997, title={The effect of water-ethanol concentration on the measured density and free volume of poly[1-(trimethylsilyl)-1-propyne]}, volume={71}, journal={Russian Journal of Physical Chemistry}, author={Volkov, V. V. and Khotimsky, V. S. and Gokzshaev, M. B. and Litvinova, E. G. and Fadeev, A. G. and Kelley, S. S.}, year={1997}, pages={1396} }
 @misc{wilson_posey-dowty_kelley_1996, title={Controlled release matrix system using cellulose acetate/poly-2-ethyl-2-oxazoline blends}, volume={5,536,505}, number={1996 Jul. 16}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Wilson, A. K. and Posey-Dowty, J. D. and Kelley, S. S.}, year={1996} }
 @misc{wilson_posey-dowty_kelley_1996, title={Controlled release matrix system using cellulose acetate/polyvinylpyrrolidone blends}, volume={5,523,095}, number={1996 Jun. 4}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Wilson, A. K. and Posey-Dowty, J. D. and Kelley, S. S.}, year={1996} }
 @inbook{kelley_wang_myers_johnson_scahill_1996, title={Use of biomass pyrolysis oils for preparation of modified phenol formaldehyde resins}, ISBN={1858610184}, booktitle={Advances in thermochemical conversion of biomass}, publisher={Chapman-Hall}, author={Kelley, S. S. and Wang, X-M and Myers, M. D. and Johnson, D. J. and Scahill, J. W.}, year={1996} }
 @article{shojaie_rials_kelley_1995, title={PREPARATION AND CHARACTERIZATION OF CELLULOSE-ACETATE ORGANIC-INORGANIC HYBRID FILMS}, volume={58}, ISSN={["0021-8995"]}, DOI={10.1002/app.1995.070580807}, abstractNote={Abstract}, number={8}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={SHOJAIE, SS and RIALS, TG and KELLEY, SS}, year={1995}, month={Nov}, pages={1263–1274} }
 @article{rivard_moens_roberts_brigham_kelley_1995, title={STARCH ESTERS AS BIODEGRADABLE PLASTICS - EFFECTS OF ESTER GROUP CHAIN-LENGTH AND DEGREE OF SUBSTITUTION ON ANAEROBIC BIODEGRADATION}, volume={17}, ISSN={["0141-0229"]}, DOI={10.1016/0141-0229(94)00120-g}, abstractNote={A novel series of starch esters was prepared, which varied both in degree of substitution (DS) and in ester group chain length (C-2 to C-6). Proton nuclear magnetic resonance-based characterization of esterified starch polymers was determined to be superior to standard saponification digestion (SD) analysis. The effects of starch modification on the anaerobic biodegradation potential for the polymer were assessed using the biochemical methane potential (BMP) protocol. Results indicate that increasing the starch ester group chain length necessitates lower levels of substitution to achieve substantial biologic degradation of the polymer.}, number={9}, journal={ENZYME AND MICROBIAL TECHNOLOGY}, author={RIVARD, C and MOENS, L and ROBERTS, K and BRIGHAM, J and KELLEY, S}, year={1995}, month={Sep}, pages={848–852} }
 @misc{landry_teegarden_edgar_kelley_1994, title={Miscible blends of cellulose esters and vinylphenol containing polymers}, volume={5,302,637}, number={1994 Apr. 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Landry, C. J. and Teegarden, D. M. and Edgar, K. J. and Kelley, S. S.}, year={1994} }
 @article{shojaie_rials_kelley_1993, title={Preparation and characterization of new cellulosic-based organic/inorganic hybrid materials via the sol-gel process}, volume={70}, journal={Polymeric Materials: Science and Engineering}, author={Shojaie, S. S. and Rials, T. G. and Kelley, S. S.}, year={1993}, pages={431–432} }
 @misc{sand_hyatt_kelley_1992, title={Formulations of cellulose esters with arylene-bis(diaryl phosphate)s}, volume={5,104,450}, number={1992 Apr. 14}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Sand, I. D. and Hyatt, J. A. and Kelley, S. S.}, year={1992} }
 @misc{cook_kelley_1992, title={Grafted cellulose esters containing a silicon moiety}, volume={5,082,914}, number={1992 Jan 21}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cook, P. M. and Kelley, S. S.}, year={1992} }
 @misc{de oliveira_glasser_kelley_nieh_1992, title={Method of producing prepolymers from hydroxyalkyl lignin derivatives}, volume={5,102,992}, number={1992 Apr. 7}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={De Oliveira, W. and Glasser, W. G. and Kelley, S. S. and Nieh, L. S.}, year={1992} }
 @misc{de oliveira_glasser_kelley_nieh_1991, title={Method of producing star-like polymers from lignin}, volume={5,066,790}, number={1991 Nov. 19}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={De Oliveira, W. and Glasser, W. G. and Kelley, S. S. and Nieh, L. S.}, year={1991} }
 @article{buchanan_hyatt_kelley_little_1990, title={ALPHA-D-CELLOOLIGOSACCHARIDE ACETATES - PHYSICAL AND SPECTROSCOPIC CHARACTERIZATION AND EVALUATION AS MODELS FOR CELLULOSE TRIACETATE}, volume={23}, ISSN={["0024-9297"]}, DOI={10.1021/ma00218a006}, abstractNote={Les oligomeres allant de l'octaacetate α-D-cellobiose au nonacosaacetate α-D-cellononaose sont caracterises par leur point et leur chaleur de fusion et par spectrometrie RMN 1 H, 13 C et spectrometrie de masse. La RMN montre qu'a partir d'un degre de polymerisation de 7, ces oligomeres peuvent etre consideres comme des composes modeles du triacetate de cellulose. Une methode d'obtention des ions moleculaires et de fragmentation specifique des acetates de cellooligosaccharose est proposee}, number={16}, journal={MACROMOLECULES}, author={BUCHANAN, CM and HYATT, JA and KELLEY, SS and LITTLE, JL}, year={1990}, month={Aug}, pages={3747–3755} }
 @article{kelley_ward_glasser_1990, title={MULTIPHASE MATERIALS WITH LIGNIN .8. INTERPENETRATING POLYMER NETWORKS FROM POLYURETHANES AND POLYMETHYL METHACRYLATE}, volume={41}, ISSN={["0021-8995"]}, DOI={10.1002/app.1990.070411124}, abstractNote={Abstract}, number={11-12}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={KELLEY, SS and WARD, TC and GLASSER, WG}, year={1990}, pages={2813–2828} }
 @misc{de oliveira_glasser_kelley_nieh_1990, title={Method of producing prepolymers from hydroxyalkyl lignin derivatives}, volume={4,918,167}, number={1990 Apr. 7}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={De Oliveira, W. and Glasser, W. G. and Kelley, S. S. and Nieh, L. S.}, year={1990} }
 @article{kelley_ward_rials_glasser_1989, title={ENGINEERING PLASTICS FROM LIGNIN .17. EFFECT OF MOLECULAR-WEIGHT ON POLYURETHANE FILM PROPERTIES}, volume={37}, ISSN={["0021-8995"]}, DOI={10.1002/app.1989.070371014}, abstractNote={Abstract}, number={10}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={KELLEY, SS and WARD, TC and RIALS, TG and GLASSER, WG}, year={1989}, month={May}, pages={2961–2971} }
 @inbook{kelley_glasser_ward_1989, title={Effect of soft-segment content on the properties of lignin-based polyurethanes}, DOI={10.1021/bk-1989-0397.ch031}, abstractNote={Influence de la composition des PU (teneur et type de lignine, isocyanate utilise, type de segment mou: PEG, PPO) sur la Tg, le module de Young, la contrainte limite, l'allongement a la rupture. En general, la Tg, le module de Young et la resistance a la traction augmentent avec la proportion de la lignine; les proprietes mecaniques des PU prepares avec des isocyanates organiques sont en general meilleures que celles obtenues avec le diisocyanate d'hexamethylene}, number={397}, booktitle={Lignin, properties and uses}, publisher={Washington, DC: American Chemical Society}, author={Kelley, Stephen and Glasser, W. G. and Ward, T. C.}, editor={Sarkanen, S. and Glasser, W. G.Editors}, year={1989}, pages={402–413} }
 @article{kelley_glasser_ward_1989, title={MULTIPHASE MATERIALS WITH LIGNIN .9. EFFECT OF LIGNIN CONTENT ON INTERPENETRATING POLYMER NETWORK PROPERTIES}, volume={30}, ISSN={["0032-3861"]}, DOI={10.1016/0032-3861(89)90259-0}, abstractNote={Abstract A series of lignin-based polyurethane/poly(methyl methacrylate) (LPU/PMMA) interpenetrating polymer networks (IPNs) were prepared by solvent casting in film form. While the LPU/PMMA ratio remained constant (1:1), the properties of the LPU were controlled by varying the composition of the hydroxypropyl lignin polyol via chain extension with propylene oxide. An increase in the lignin content of the polyol resulted in a decrease in the molecular weight between crosslinks (Mc) and change in the morphology of the LPU/PMMA composite. This effect resulted in the transition from a two-phase material to a single-phase material when the (true) lignin content of the composite rose above 25 wt%. As the lignin content increased, the strength properties of the composites increased. The dynamic mechanical, thermal and ultimate mechanical properties of the entire series of IPNs could be explained by dual phase continuity.}, number={12}, journal={POLYMER}, author={KELLEY, SS and GLASSER, WG and WARD, TC}, year={1989}, month={Dec}, pages={2265–2268} }
 @article{puleo_paul_kelley_1989, title={THE EFFECT OF DEGREE OF ACETYLATION ON GAS SORPTION AND TRANSPORT BEHAVIOR IN CELLULOSE-ACETATE}, volume={47}, ISSN={["0376-7388"]}, DOI={10.1016/S0376-7388(00)83083-5}, abstractNote={Cellulose acetate films with degrees of substitution of 1.75, 2.45, and 2.84 were characterized in terms of chemical composition, acetyl group distribution, glass transition, crystallinity, and dynamic mechanical properties. Permeability coefficients for a series of gases, at 1 atm and 35°C, were found to increase with degree of acetylation. Sorption isotherms for CO2 and CH4 at 35°C were analyzed in terms of the dual-mode sorption model, and it was shown that conditioning of the films by CO2 caused an increase in the Langmuir sorption capacity. The permeability of CO2 was found to increase with pressure above 10 atm due to plasticization. Highly sorbing CO2 swells the polymer such that interchain interactions are disrupted and segmental mobility increases. Infrared analyses support this conclusion and show that after complete removal of CO2 and a sufficient relaxation period, the cellulose acetate returned to its original condition. Therefore, the response of the films to plasticization by CO2 is not only time and pressure dependent but also reversible.}, number={3}, journal={JOURNAL OF MEMBRANE SCIENCE}, author={PULEO, AC and PAUL, DR and KELLEY, SS}, year={1989}, month={Dec}, pages={301–332} }
 @article{kelley_glasser_ward_1988, title={ENGINEERING PLASTICS FROM LIGNIN .14. CHARACTERIZATION OF CHAIN-EXTENDED HYDROXYPROPYL LIGNINS}, volume={8}, ISSN={["0277-3813"]}, DOI={10.1080/02773818808070689}, abstractNote={Abstract Three series of chain-extended hydroxypropyl lignins (CEEQLs), prepared fran oqanosolv and kraft lignin, were examined regarding their chemical, molecular weight and them1 characteristics. Results showed that the molar substitution (MS) of propylene oxide, which was defined as the number of propoxy repeat units which comprise the chain attached to a single reactive site on lignin, varied and affected copolymer properties. As the MS increased from 1 to 7.2, the number average molecular weight (Mg) increased while the glass transition temperature (Tg) decreased. The actual Mg observed by GPC exceeded however that expected on the basis of mass gain by derivatization. This was attributed to changes in the apparent hydrodynamic volume in relation to MS. The change in Tg with increasing MS followed the Gordon-Taylor relationship. Differences in the chemical composition of the original lignin (organosolv or Kraft) were not obvious as the lignin content of the copolymer decreased below 50%.}, number={3}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={KELLEY, SS and GLASSER, WG and WARD, TC}, year={1988}, pages={341–359} }
 @article{kelley_glasser_ward_1988, title={ENGINEERING PLASTICS FROM LIGNIN .15. POLYURETHANE FILMS FROM CHAIN-EXTENDED HYDROXYPROPYL LIGNIN}, volume={36}, ISSN={["0021-8995"]}, DOI={10.1002/app.1988.070360403}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={KELLEY, SS and GLASSER, WG and WARD, TC}, year={1988}, month={Aug}, pages={759–772} }
 @inproceedings{glasser_rials_kelley_ward_1988, title={Engineered lignin-containing materials with multiphase morphology}, booktitle={Proceedings of the International Symposium on Wood and Pulping Chemistry}, author={Glasser, W. G. and Rials, T. G. and Kelley, S. S. and Ward, T. C.}, year={1988}, pages={35–38} }
 @inbook{glasser_kelley_1987, title={Lignin}, volume={8}, ISBN={0471809373}, booktitle={Encyclopedia of polymer science and engineering}, publisher={New York: John Wiley and Sons}, author={Glasser, W. G. and Kelley, S. S.}, year={1987}, pages={795–852} }
 @article{kelley_rials_glasser_1987, title={RELAXATION BEHAVIOR OF THE AMORPHOUS COMPONENTS OF WOOD}, volume={22}, ISSN={["0022-2461"]}, DOI={10.1007/BF01160778}, number={2}, journal={JOURNAL OF MATERIALS SCIENCE}, author={KELLEY, SS and RIALS, TG and GLASSER, WG}, year={1987}, month={Feb}, pages={617–624} }
 @article{kelley_gollob_wellons_1986, title={THE EFFECTS OF RESIN FORMULATION VARIABLES ON THE DYNAMIC MECHANICAL-PROPERTIES OF ALKALINE CURING PHENOLIC RESINS}, volume={40}, ISSN={["0018-3830"]}, DOI={10.1515/hfsg.1986.40.5.303}, abstractNote={Torsional braid analysis (TBA) was used to study the effects of formulation variables on the properties of phenol-formaldehyde resins. These variables were the mole ratio of formaldehyde to phenol (F/P), the ratio of initial and total sodium hydroxide to phenol (i-NaOH and t-NaOH, respectively), and presence or absence of a Iow temperature (60°C) hold during the resin cook. Analysis of the resins during eure showed that the initial relative rigidity and mechanical damping were determined by the molecular weight and viscosity of the resin. The relative rigidity of the fülly cured resin was strongly influenced by the F/P, t-NaOH and the presence of a Iow temperature methylolation step. A high F/P (2.5) and a high t-NaOH (0.75) both promoted a high relative rigidity in the cured resin.}, number={5}, journal={HOLZFORSCHUNG}, author={KELLEY, SS and GOLLOB, L and WELLONS, JD}, year={1986}, month={Oct}, pages={303–308} }
 @inbook{kelley_muller_newman_glasser_1985, title={Engineering plastics from lignin, a general approach and specific examples}, ISBN={0935018328}, booktitle={Wood adhesives in 1985: status and needs}, publisher={Madison, WI: Forest Products Research Society}, author={Kelley, S. S. and Muller, P. C. and Newman, W. H. and Glasser, W. G.}, editor={R. H. Gillespie, A. W. Chrtistiansen and G. E. Myers and River, B. H.Editors}, year={1985}, pages={197–210} }
 @inbook{young_fujita_kelley_rammon_rivers_gillespie_1985, title={Enhanced wood bond strength through surface treatments}, ISBN={0935018328}, booktitle={Wood adhesives in 1985: status and needs}, publisher={Madison WI: Forest Products Research Society}, author={Young, R. A. and Fujita, M. and Kelley, S. S. and Rammon, R. M. and Rivers, B. H. and Gillespie, R. H.}, editor={R. H. Gillespie, A. W. Chrtistiansen and G. E. Myers and River, B. H.Editors}, year={1985}, pages={237–255} }
 @inproceedings{glasser_kelley_rials_saraf_ward_1985, title={prospects for engineered materials from lignin}, ISBN={0919893244}, booktitle={Proceedings of the International Symposium on Wood and Pulping Chemistry}, author={Glasser, W. G. and Kelley, S. S. and Rials, T. G. and Saraf, V. P. and Ward, T. C.}, year={1985} }
 @article{muller_kelley_glasser_1984, title={ENGINEERING PLASTICS FROM LIGNIN .9. PHENOLIC RESIN SYNTHESIS AND CHARACTERIZATION}, volume={17}, ISSN={["0021-8464"]}, DOI={10.1080/00218468408074929}, abstractNote={Abstract The performance of phenol-formaldehyde (PF) resins, formulated with lignin derivatives previously synthesized as phenolic resin prepolymers, was evaluated by thermal analysis of the curing process, and by a hard maple shear block test. At 54 and 60% phenol replacement levels, respectively, kraft (KL) and steam explosion lignin (SEL)-based resoles exhibited cure behavior very similar to a standard PF resin. Acid hydrolysis lignin gelled prematurely, and was found to be incompatible with the normal synthesis procedure. Differential scanning calorimetry (DSC) was used to compare kinetic parameters for the curing process of neat and lignin derived phenolic resins. Activation energies and cure rates determined by DSC showed no difference between adhesives. High lignin contents had no inhibitory effect on resin cure. Shear strength properties were evaluated in a compression test, and results illustrate that both lignin-based resins have acceptable strength properties, both in a dry and accelerated agin...}, number={3}, journal={JOURNAL OF ADHESION}, author={MULLER, PC and KELLEY, SS and GLASSER, WG}, year={1984}, pages={185–206} }
 @article{kelley_young_rammon_gillespie_1983, title={Bond formation by wood surface reactions. Part III. Parameters affecting the bond strength of wood panels}, volume={33}, number={2}, journal={Forest Products Journal}, author={Kelley, S. S. and Young, R. A. and Rammon, R. M. and Gillespie, R. H.}, year={1983}, pages={21–28} }
 @inproceedings{glasser_barnett_rials_kelley_1983, title={Synthesis and characterization of hydroxypropyl lignin derivatives}, booktitle={Proceedings of the International Symposium on Wood and Pulping Chemistry}, author={Glasser, W. G. and Barnett, C. A. and Rials, T. G. and Kelley, S. S.}, year={1983}, pages={89–94} }
 @article{rammon_kelley_young_gillespie_1982, title={BOND FORMATION BY WOOD SURFACE-REACTIONS .2. CHEMICAL MECHANISMS OF NITRIC-ACID ACTIVATION}, volume={14}, ISSN={["0021-8464"]}, DOI={10.1080/00218468208073207}, abstractNote={Abstract Previous research on chemical bonding has shown that a wood bond can be achieved by surface reactions when the wood is chemically activated prior to pressing. Activation by nitric acid appears to produce the most consistent results. The objective of this study was to elucidate the chemical mechanisms of nitric acid activation through the use of analytical instrumental techniques and identification of wood degradation products. Infrared and ultra-violet spectroscopic analysis of nitric acid treated sugar maple and isolated wood polymers indicated extensive oxidation, nitration and hydrolysis of the wood polysaccharides and lignin. The major effects were noted at ambient temperature although additional treatment at 100°C caused further modification. The lignin and xylan (hemicellulose) were the most extensively modified components as monitored by Klason lignin, Kjeldahl nitrogen and sugar analyses. Lignin is heavily nitrated and over 30% of the xylan (xylose) is lost during nitric acid treatment. T...}, number={3-4}, journal={JOURNAL OF ADHESION}, author={RAMMON, RM and KELLEY, SS and YOUNG, RA and GILLESPIE, RH}, year={1982}, pages={257–282} }
 @article{young_rammon_kelley_gillespie_1982, title={Bond formation by wood surface reactions. Part I. Surface analysis by ESCA}, volume={14}, number={3}, journal={Wood Science}, author={Young, R. A. and Rammon, R. M. and Kelley, S. S. and Gillespie, R. H.}, year={1982}, pages={110–119} }
 @article{kelley_young_rammon_gillespie_1982, title={Bond formation by wood surface reactions. Part IV. Analysis of Furfuryl Alcohol, Tannin and Maleic Acid Bridging Agents}, volume={2}, DOI={10.1080/02773818208085138}, abstractNote={Abstract Solid wood panels (Acer saccharum Marsh.) were bonded with various bridging materials following nitric acid activation. These chemical bridging materials included tannin, furfuryl alcohol and mixtures of the two with and without maleic acid. High shear strengths were achieved with a tannin-furfuryl alcohol-maleic acid mixture (T-F-M) with or without the nitric acid activation. The curing reactions of the bridging material were examined with differential scanning calorimetry (DSC). Furfuryl alcohol was found to be the most reactive component of the T-F-M. Results from both the bonding work and the DSC analysis showed little effect of open assembly time or pot-life. The furfuryl alcohol appeared to be nitrated by the nitric acid catalyst. The nitrated material apparently degraded at high temperature (180 C) in a violent reaction detected by DSC. While these reactions were not observed with the panels the possibility of violent reactions during pressing must be considered.}, number={3}, journal={Journal of Wood Chemistry and Technology}, author={Kelley, Stephen and Young, R. A. and Rammon, R. M. and Gillespie, R. H.}, year={1982}, pages={317–342} }