@article{banerjee_saveliev_2020, title={Emission Characteristics of Heat Recirculating Porous Burners With High Temperature Energy Extraction}, volume={8}, ISSN={["2296-2646"]}, DOI={10.3389/fchem.2020.00067}, abstractNote={Emission characteristics of heat recirculating porous burners with high temperature heat extraction are studied numerically. Two types of burners are considered: counterflow porous burner (CFB) and reciprocal counterflow porous burner (RCFB). The combustion of methane-air mixtures flowing through the porous media is modeled by solving steady state governing equations to obtain the flame temperature and species profiles. Formation of CO, NO, NO2, and NOx is studied in CFB and RCFB in a range of equivalence ratios from 0.3 to 1.0 and heat extraction temperatures from 300 to 1,300 K. The contribution of various NO formation mechanisms is comparatively analyzed and related to the NO generation predicted by a detailed chemistry mechanism. The effect of high temperature heat extraction on the formation of CO and NOx is analyzed. Numerical predictions indicate a constant monotonic decrease of NOx concentration with increasing temperature of energy extraction. The formation of CO is observed to follow the similar trend. For heat extraction at 1,300 K, simulations predicted 3.6 ppm of NOx and 3.9 ppm of CO for CFB and 4.1 ppm of NOx and 3.5 ppm of CO for RCFB when these burners are operated at an equivalence ratio of 0.7.}, journal={FRONTIERS IN CHEMISTRY}, author={Banerjee, Abhisek and Saveliev, Alexei}, year={2020}, month={Feb} }
 @article{banerjee_kundu_gnatenko_zelepouga_wagner_chudnovsky_saveliev_2020, title={NOx Minimization in Staged Combustion Using Rich Premixed Flame in Porous Media}, volume={192}, ISSN={["1563-521X"]}, DOI={10.1080/00102202.2019.1622532}, abstractNote={ABSTRACT Two-stage combustion of methane/air is studied experimentally and numerically with a focus on achieving ultralow NOx emissions. The primary flame is a rich premixed flame in the porous medium. The flame is stabilized in the range of equivalence ratios from 1.1 to 1.7 using upstream heat extraction. The products of the primary flame are rich in the partial oxidation and reforming products such as CO, H2, and CH4. Due to the self-regulated heat losses from the flame the maximum flame temperature of the primary flame remains close to 1700 K. The rich-flame environment and low-flame temperatures limit NOx formation in the primary flame. The NOx emission index of the primary flame shows a maximum at the equivalence ratio of 1.1 and reduces for richer mixtures. The products of the primary flame are burned in the secondary nonpremixed flame. The products could be intercooled to reduce temperature and minimize NOx formation in the secondary nonpremixed flame. The emission index of the secondary flame increases with the equivalence ratio. Variation of combined emission index shows a minimum value at the equivalence ratio of 1.2. The trend remains consistent with the intercooling of the primary flame products.}, number={9}, journal={COMBUSTION SCIENCE AND TECHNOLOGY}, author={Banerjee, Abhisek and Kundu, Prithwish and Gnatenko, Vitaliy and Zelepouga, Serguei and Wagner, John and Chudnovsky, Yaroslav and Saveliev, Alexei}, year={2020}, month={Sep}, pages={1633–1649} }
 @article{yao_saveliev_2018, title={High efficiency high temperature heat extraction from porous media reciprocal flow burner: Time-averaged model}, volume={143}, ISSN={["1359-4311"]}, DOI={10.1016/j.applthermaleng.2018.07.144}, abstractNote={Abstract The high temperature heat extraction from a porous media reciprocal flow burner (RFB) is studied numerically. In RFB, the air/fuel mixture flow direction is switched periodically to contain and sustain combustion. High temperature heat extraction is essential for the efficient operation of small electrical and thermal systems based on thermoelectric generators, Stirling engines and micro-turbines. In this paper, the efficiency of the heat extraction is studied for different extraction locations, temperatures and equivalence ratios. An 1-D time-averaged model is developed and validated to represent a RFB and to further predict the behavior of the burner. Optimization on the burner’s geometry is also performed to increase the heat extraction efficiency.}, journal={APPLIED THERMAL ENGINEERING}, author={Yao, Zhaoxi and Saveliev, Alexei V}, year={2018}, month={Oct}, pages={614–620} }
 @article{banerjee_saveliev_2018, title={High temperature heat extraction from counterflow porous burner}, volume={127}, ISSN={["1879-2189"]}, DOI={10.1016/j.ijheatmasstransfer.2018.08.027}, abstractNote={Energy extraction from an adiabatic regenerative porous burner is studied numerically. Steady state governing equations are solved to predict the fluid and thermal properties of the system. The temperature of heat extraction is varied from 300 K to 1300 K. The numerical simulation predicts the effect of efficiency of energy extraction on the location and extraction temperature of heat exchangers. Higher extraction temperatures tend to decrease the extracted energy and consequently raise the exhaust temperature of the burner. Two burner configurations are studied comparatively by changing the properties of the wall separating the incoming reactants from the exhaust gases. Out of the two materials used to study the effect of separation wall on energy extraction, the study predicts higher gains for alumina as compared to silicon carbide. The maximum heat extraction efficiency of 35% is reported for extraction at 1300 K when silicon carbide separation wall is used in the burner. Whereas for porous burner with alumina separation wall, 60% of the heat can be extracted at 1300 K.}, journal={INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER}, author={Banerjee, Abhisek and Saveliev, Alexei V}, year={2018}, month={Dec}, pages={436–443} }
 @article{choi_saveliev_2017, title={Oscillatory coalescence of droplets in an alternating electric field}, volume={2}, ISSN={["2469-990X"]}, DOI={10.1103/physrevfluids.2.063603}, abstractNote={Experiments show that a pair of droplets in an alternating electric field coalesce through a repeated sequence: dipole-dipole attraction, the formation of liquid bridge, the repulsion of equipotential droplets, the elongation and breakup of the bridge.}, number={6}, journal={PHYSICAL REVIEW FLUIDS}, author={Choi, Suhwan and Saveliev, Alexei V.}, year={2017}, month={Jun} }
 @article{kribs_shah_hutchins_reach_muncey_june_saveliev_lyons_2016, title={The stabilization of partially-premixed jet flames in the presence of high potential electric fields}, volume={84}, ISSN={["1873-5738"]}, DOI={10.1016/j.elstat.2016.08.002}, abstractNote={Numerous research efforts have focused on flame stabilization and emissions. Based on initial experiments, specific mechanisms resulting from DC electric fields were chosen to be investigated, namely the chemical, thermal, and ionization mechanisms. Numerical simulations were performed on premixed propane-ozone-air flames to characterize ozone effects on flame speed resulting from the formation of ozone in high potential electric fields. These results were compared against partially premixed flame experiments to observe the dominant influences within leading edge stabilization within high potential electric fields. It was found that the electromagnetic or ionization influences, serve as the dominant effect on the combustion zone.}, journal={JOURNAL OF ELECTROSTATICS}, author={Kribs, James D. and Shah, Parth V. and Hutchins, Andrew R. and Reach, William A. and Muncey, Richard D. and June, M. Sean and Saveliev, Alexei and Lyons, Kevin M.}, year={2016}, month={Dec}, pages={1–9} }
 @article{farmahini-farahani_saveliev_merchan-merchan_2017, title={Volumetric flame synthesis of mixed tungsten-molybdenum oxide nanostructures}, volume={36}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2016.08.054}, abstractNote={Mixed-metal (Mo/W) oxide nanostructures were synthesized volumetrically in the oxygen-rich zone of a counter-flow diffusion flame. High purity Mo and W wires were used to generate Mo and W oxide vapors that are transformed into mixed-metal oxide nanostructures while transported by the gas flow in the upward direction toward the stagnation plane. The Mo wire was inserted in a lower position within the flame volume than the W wire. Samples of generated nanomaterials collected thermophoretically from the flame volume at various axial positions allowed tracing of the particle evolution. The following synthesis stages were identified. MoO3 structures are first formed in the lower part of the flame. As they are carried by the gas flow, W oxide vapors deposit on the surfaces of the early formed MoO3 nanostructures. W atoms diffuse at the interfaces of the MoO3 structures to form mixed W–Mo oxide nanoparticles. Fully grown structures, collected near the stagnation plane (SP), are nanocubes exhibiting well-defined edges with sizes less than 100 nm. Energy-dispersive X-ray spectroscopy elemental mapping revealed that the mature structures have uniform distribution of W, Mo, and O atoms. The measured lattice spacing showed expanded lattice distance of MoO3 which may be attributed to the incorporation of W atoms in the MoO3 crystal and formation of W–Mo oxide structures.}, number={1}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Farmahini-Farahani, Moien and Saveliev, Alexei V. and Merchan-Merchan, Wilson}, year={2017}, pages={1055–1063} }
 @article{choi_saveliev_2014, title={In situ emulsification using a non-uniform alternating electric field}, volume={105}, ISSN={["1077-3118"]}, DOI={10.1063/1.4893670}, abstractNote={We report an electric field based method for in situ emulsification of water droplets immersed in a continuous oil phase. High density water-in-oil emulsions are generated using non-uniform ac electric fields applied between needle and plate electrodes. An initial water droplet is entrained in the area of high electric field near the needle electrode where it is dispersed under the influence of high electric stresses. Breakup mechanisms responsible for a gradual dispersion of the water droplets are investigated. Identified mechanisms involve drop elongation to a cylindrical shape followed by a capillary breakup, ac electrospraying from individual water droplets, and formation and breakup of bead-like structures comprised by the water droplets interconnected by thin water bridges. Water droplets with diameters close to 1 μm and a narrow size distribution are formed at long processing times. The generated emulsion has a well-defined boundary and is confined near the needle electrode in a shape resembling a ...}, number={7}, journal={APPLIED PHYSICS LETTERS}, author={Choi, Suhwan and Saveliev, Alexei V.}, year={2014}, month={Aug} }
 @inproceedings{chudnovsky_zelepouga_saveliev_wagner_gnatenko_2015, title={Nox reduction in partially premixed flames by flue gas recirculation}, DOI={10.1115/imece2014-39367}, abstractNote={The authors are currently investigating new technical (both design and operation) approach, which is expected to enable the improvement of the performance of partially premixed type burners without jeopardizing the simplicity, cost, and reliability that this type of burners are well known for. The improvements include significant reduction of the NOx emission without substantial redesign of the combustion system. The results of the experimental investigation of burner operation and design improvements are to be presented and further discussed at the podium.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2014, vol 8b}, author={Chudnovsky, Y. and Zelepouga, S. and Saveliev, A. and Wagner, J. and Gnatenko, V.}, year={2015} }
 @article{toledo_utria_saveliev_2014, title={Ultrarich Filtration Combustion of Ethane}, volume={28}, ISSN={["1520-5029"]}, DOI={10.1021/ef402264a}, abstractNote={Ultrarich filtration combustion of ethane is studied in a porous medium composed of alumina spheres with the aim to achieve optimized conversion to hydrogen and syngas. Temperature, velocities, and chemical products of the combustion waves are recorded experimentally in a range of equivalence ratios ϕ from stoichiometry (ϕ = 1) to ϕ = 2.5. Experimental and numerical results are reported for 3.5 mm diameter alumina spheres; an oxygen content of the oxidizer is varied from 21 to 30%. Two temperature models based on GRI-MECH 3.0 and San Diego-MECH demonstrated good agreement with the experimental results. The maximum hydrogen concentration of 19.3% was recorded at ϕ = 2.5 and a 30% oxygen content in the oxidizer.}, number={2}, journal={ENERGY & FUELS}, author={Toledo, Mario and Utria, Ithriscia and Saveliev, Alexei V.}, year={2014}, month={Feb}, pages={1536–1540} }
 @article{srivastava_desai_merchan-merchan_saveliev_2015, title={Volumetric flame synthesis of one-dimensional molybdenum oxide nanostructures}, volume={35}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2014.05.044}, abstractNote={A laminar counter-flow diffusion flame formed with methane/acetylene and oxygen enriched-air was used for the controlled synthesis of 1-D molybdenum oxide nanostructures directly in the gas phase. Raw material was introduced into the oxidizer side of the flame in the form of solid molybdenum wires with ∼99% purity. Molybdenum oxide vapors formed in the gas phase were transported by the gas flow in the flame environment possessing strong thermal and chemical gradients. The generated nanostructures were collected thermophoretically from the flame volume. Essential morphological variations of generated nanomaterials were observed depending on sampling position within the flame volume and probe parameters. The mechanism behind the synthesis of the spherical and 1-D nanoforms is analyzed and modeled numerically. The nanorod growth model involves monomer transport, nucleation and growth. The monomer formation is through the oxidation and vaporization of the probe material. The nucleation model is based on the classical nucleation theory. The model predicts the trajectory and growth of the formed nuclei as they are transported in the flame volume. It is considered that the ends of the cylindrical 1-D nanorods grow by the phenomenon of rough growth while the lateral faces exhibit layered growth. The growth model also considers the contribution of the monomers diffusing on the nanoparticle surface as well as the effect of the atoms impinging directly onto the growth sites and compares their relative contributions. The model qualitatively predicts the variation of aspect ratio of the formed nanomaterials with increase of monomer concentration as observed in the experiments.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Srivastava, S. and Desai, M. and Merchan-Merchan, W. and Saveliev, A. V.}, year={2015}, pages={2307–2314} }
 @article{rasipuram_wu_kuznetsov_kuznetsov_levine_jasper_saveliev_2013, title={Submicrometre particle filtration with a dc activated plasma textile}, volume={47}, ISSN={0022-3727 1361-6463}, url={http://dx.doi.org/10.1088/0022-3727/47/2/025201}, DOI={10.1088/0022-3727/47/2/025201}, abstractNote={Plasma textiles are novel fabrics incorporating the advantages of cold plasma and low-cost non-woven or woven textile fabrics. In plasma textiles, electrodes are integrated into the fabric, and a corona discharge is activated within and on the surface of the fabric by applying high voltages above 10 kV between the electrodes. When the plasma textile is activated, submicrometre particles approaching the textile are charged by the deposition of ions and electrons produced by the corona, and then collected by the textile material. A stable plasma discharge was experimentally verified on the surface of the textile that was locally smooth but not rigid. A filtration efficiency close to 100% was observed in experiments conducted on salt particles with diameters ranging from 50 to 300 nm. Unlike conventional fibrous filters, the plasma textile provided uniform filtration in this range, without exhibiting a maximum particle penetration size.}, number={2}, journal={Journal of Physics D: Applied Physics}, publisher={IOP Publishing}, author={Rasipuram, S C and Wu, M and Kuznetsov, I A and Kuznetsov, A V and Levine, J F and Jasper, W J and Saveliev, A V}, year={2013}, month={Dec}, pages={025201} }
 @article{winfrey_abd al-halim_gilligan_saveliev_bourham_2012, title={A Study of Plasma Parameters in a Capillary Discharge With Calculations Using Ideal and Nonideal Plasma Models for Comparison With Experiment}, volume={40}, ISSN={["0093-3813"]}, DOI={10.1109/tps.2011.2179985}, abstractNote={A study of the plasma parameters in a capillary discharge was conducted using an experimental electrothermal plasma facility. The experimental results are compared to calculations using ideal and nonideal formulas of the Coulomb logarithm in the plasma electrical conductivity model to determine the nature of the plasma regime. Calculations are compared to the measured ablated mass, the measured electrical conductivity. Other calculated parameters are compared to results from similar and typical discharges. The measured ablated mass falls in between the ideal and nonideal calculations suggesting that the plasma is neither ideal nor nonideal; however, the linear fit of the experimental and calculated values shows divergence in the ideal calculations at higher peak currents. Measured plasma electrical conductivity is close to the ideal model predictions at lower values of the peak discharge current and approaches the nonideal model predictions at higher peak currents; the shape of the measured conductivity follows that of the nonideal model.}, number={3}, journal={IEEE TRANSACTIONS ON PLASMA SCIENCE}, author={Winfrey, A. Leigh and Abd Al-Halim, Mohamed A. and Gilligan, John G. and Saveliev, Alexei V. and Bourham, Mohamed A.}, year={2012}, month={Mar}, pages={843–852} }
 @article{kuznetsov_saveliev_rasipuram_kuznetsov_brown_jasper_2012, title={Development of Active Porous Medium Filters Based on Plasma Textiles}, volume={1453}, ISSN={["0094-243X"]}, DOI={10.1063/1.4711186}, abstractNote={Inexpensive, flexible, washable, and durable materials that serve as antimicrobial filters and self-decontaminating fabrics are needed to provide active protection to people in areas regularly exposed to various biohazards, such as hospitals and bio research labs working with pathogens. Airlines and cruise lines need such material to combat the spread of infections. In households these materials can be used in HVAC filters to fight indoor pollution, which is especially dangerous to people suffering from asthma. Efficient filtering materials are also required in areas contaminated by other types of hazardous dust particulates, such as nuclear dust. The primary idea that guided the undertaken study is that a microplasma-generating structure can be embedded in a textile fabric to generate a plasma sheath (“plasma shield”) that kills bacterial agents coming in contact with the fabric. The research resulted in the development of a plasma textile that can be used for producing new types of self-decontaminating ...}, journal={POROUS MEDIA AND ITS APPLICATIONS IN SCIENCE, ENGINEERING, AND INDUSTRY}, publisher={AIP}, author={Kuznetsov, Ivan A. and Saveliev, Alexei V. and Rasipuram, Srinivasan and Kuznetsov, Andrey V. and Brown, Alan and Jasper, Warren}, year={2012}, pages={265–270} }
 @article{winfrey_abd al-halim_saveliev_gilligan_bourham_2013, title={Enhanced Performance of Electrothermal Plasma Sources as Fusion Pellet Injection Drivers and Space Based Mini-Thrusters via Extension of a Flattop Discharge Current}, volume={32}, ISSN={["0164-0313"]}, DOI={10.1007/s10894-012-9578-5}, number={3}, journal={JOURNAL OF FUSION ENERGY}, author={Winfrey, A. Leigh and Abd Al-Halim, Mohamed A. and Saveliev, Alexei V. and Gilligan, John G. and Bourham, Mohamed A.}, year={2013}, month={Jun}, pages={371–377} }
 @article{merchan-merchan_saveliev_sanmiguel_farahani_2012, title={Flame volume synthesis of carbon-coated WO3 nanoplatelets and nanorods}, volume={14}, ISSN={["1572-896X"]}, DOI={10.1007/s11051-012-1276-8}, number={12}, journal={JOURNAL OF NANOPARTICLE RESEARCH}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Sanmiguel, Sergio Granados and Farahani, Moien Farmahini}, year={2012}, month={Dec} }
 @article{toledo_utria_gonzalez_zuniga_saveliev_2012, title={Hybrid filtration combustion of natural gas and coal}, volume={37}, ISSN={["0360-3199"]}, DOI={10.1016/j.ijhydene.2012.01.061}, abstractNote={Rich and ultrarich combustion of natural gas in a porous medium composed of aleatory coal particles and alumina spheres was studied experimentally to evaluate the suitability of the concept for hydrogen and syngas production. Temperature, velocity and chemical products of the combustion waves were recorded experimentally in two stages: (1) natural gas in an inert porous medium at filtration velocities of 12, 15 and 19 cm/s for equivalence ratios (φ) from φ = 1.0 to φ = 3.8; (2) natural gas in a porous medium composed of coal and alumina particles for a range of volume coal fractions from 0 to 75% at φ = 2.3, and a filtration velocity of 15 cm/s. It was observed that the flame temperatures and hydrogen yields were increased with the increase of filtration velocity in inert porous media. In hybrid porous media the flame temperature decreased with an increase of coal fraction, and hydrogen and carbon monoxide were dominant partial oxidation products. Syngas yield in hybrid filtration combustion was found to be essentially higher than for the inert porous medium case. The maximum hydrogen conversion for the hybrid coal and alumina bed was ∼55% for a volumetric coal content of 75%.}, number={8}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Toledo, Mario G. and Utria, Khriscia S. and Gonzalez, Freddy A. and Zuniga, Juan P. and Saveliev, Alexei V.}, year={2012}, month={Apr}, pages={6942–6948} }
 @article{zheng_cheng_bingue_saveliev_cen_2012, title={Partial Oxidation of Methane in Porous Reactor: Part I. Unidirectional Flow}, volume={26}, ISSN={["1520-5029"]}, DOI={10.1021/ef300851z}, abstractNote={Partial oxidation of methane in a unidirectional flow porous reactor is studied numerically. A number of partial oxidation mechanisms affecting H2 and CO yields are comparatively analyzed using kinetic modeling for a range of rich and ultrarich equivalence ratios, residence times, and preset reactor temperatures. Temperature profiles, hydrogen yields, and methane conversion ratios are predicted for various equivalence ratios using two-temperature filtration combustion model with selected detailed chemical mechanism. The simulation results show that the hydrogen yield has two obvious sections: the ignition section and stream reforming section. The hydrogen yield increases with temperature and equivalence ratio increase. The two-temperature model results show a good qualitative agreement with the experimental results especially for the maximum solid temperature and hydrogen production. The wave starts to propagate downstream at φ > 1.5. The maximum solid temperature decreases from 1760 K to 1665 K as the eq...}, number={8}, journal={ENERGY & FUELS}, author={Zheng, Chenghang and Cheng, Leming and Bingue, Jacques P. and Saveliev, Alexei and Cen, Kefa}, year={2012}, month={Aug}, pages={4849–4856} }
 @inproceedings{jangale_saveliev_zelepouga_gnatenko_pratapas_2012, title={Heating value sensor for producer gas}, DOI={10.1115/icef2011-60197}, abstractNote={Today, producer gas is being utilized as a fuel gas in boilers, internal combustion engines and turbines for heat and power generation. The composition of producer gas varies depending upon the gasification parameters. For improved process control and optimum utilization of these heat and power generating systems, it is desirable to monitor the producer gas composition in real-time. A new method and apparatus has been developed and lab-tested for quantitative characterization of producer gas. Spectroscopic and non-spectroscopic measurements are performed in order to detect both — spectrally active and inactive gases. Both methods are cross-sensitive to more than one gas. The measurements are then processed using multivariate statistical methods — principal components regression and partial least squares to fit a regression model which correlates the experimental measurements to the composition and heating value of producer gas. The fitted regression model is used to estimate the properties of unknown mixtures. The measurements and data processing are done in real time using a high speed hardware control and data acquisition system. A commercialized version of this sensor is expected to cost less than half the price of gas chromatographs, which are widely used in the gas industry today.}, booktitle={Proceedings of the ASME Internal Combustion Engine Division Fall Technical Conference (ICEF)}, author={Jangale, V. V. and Saveliev, A. and Zelepouga, S. and Gnatenko, V. and Pratapas, J. M.}, year={2012}, pages={817–822} }
 @article{kuznetsov_greenfield_mehta_merchan-merchan_salkar_saveliev_2011, title={Increasing the solar cell power output by coating with transition metal-oxide nanorods}, volume={88}, ISSN={["0306-2619"]}, DOI={10.1016/j.apenergy.2011.04.033}, abstractNote={Photovoltaic cells produce electric current through interactions among photons from an ambient light source and electrons in the semiconductor layer of the cell. However, much of the light incident on the panel is reflected or absorbed without inducing the photovoltaic effect. Transition metal-oxide nanoparticles, an inexpensive product of a process called flame synthesis, can cause scattering of light. Scattering can redirect photon flux, increasing the fraction of light absorbed in the thin active layer of silicon solar cells. This research aims to demonstrate that the application of transition metal-oxide nanorods to the surface of silicon solar panels can enhance the power output of the panels. Several solar panels were coated with a nanoparticle-methanol suspension, and the power outputs of the panels before and after the treatment were compared. The results demonstrate an increase in power output of up to 5% after the treatment. The presence of metal-oxide nanorods on the surface of the coated solar cells is confirmed by electron microscopy.}, number={11}, journal={APPLIED ENERGY}, author={Kuznetsov, I. A. and Greenfield, M. J. and Mehta, Y. U. and Merchan-Merchan, W. and Salkar, G. and Saveliev, A. V.}, year={2011}, month={Nov}, pages={4218–4221} }
 @article{winfrey_abd al-halim_gilligan_saveliev_bourham_2011, title={MODELING OF AN ABLATION-FREE ELECTROTHERMAL PLASMA PELLET ACCELERATOR}, volume={60}, ISSN={["1536-1055"]}, DOI={10.13182/fst60-480}, abstractNote={Abstract Electromagnetic and electrothermal launch devices can provide high acceleration and inject pellets with speeds in excess of 3 km/s for masses up to 3gm. However, the ablation of the bore adds impurities to the plasma. An ablation-free electrothermal pellet accelerator is a concept that utilizes an ablation-free capillary discharge in which a quartz capillary is coated with a nanocrystalline diamond film (NCD). The ablation-free capillary connects to an extension tube, which is also an ablation-free quartz tube coated with NCD that serves as the acceleration barrel. An ablation-free capillary discharge computer code has been developed to model plasma flow and acceleration of pellets for fusion fueling in magnetic fusion reactors. The code incorporates ideal and non-ideal conductivity models and has a set of governing equations for the capillary, the acceleration tube, and the pellet. The capillary generates the plasma from hydrogen/deuterium gas when the discharge current flows through the capillary. The pellet starts moving in the extension tube when the pressure of the plasma flow from the capillary reaches the release limit. The code results show an exit velocity of 2.7 km/s for a 20 mg deuterium pellet when using a capillary and barrel each 9 cm long where the source and barrel diameters are 0.4cm and 0.6cm, respectively, with a discharge current of 20 kA over a 300 both the capillary and the barrel to 12 cm increases the pellet exit velocity to 2.9 km/s, and a further increase to 18cm results in a 3.15km/s pellet exit velocity. Increasing the barrel length to 36 cm, while keeping the source length at 18 cm, results in an increase in the pellet velocity to 3.32 km/s. The pellet starts moving at 35 μs reaches 3.32 km/s in 100 this velocity until exiting the acceleration tube.}, number={2}, journal={FUSION SCIENCE AND TECHNOLOGY}, author={Winfrey, A. Leigh and Abd Al-Halim, Mohamed and Gilligan, John G. and Saveliev, Alexei V. and Bourham, Mohamed A.}, year={2011}, month={Aug}, pages={480–485} }
 @article{zheng_cheng_saveliev_luo_cen_2011, title={Numerical studies on flame inclination in porous media combustors}, volume={54}, ISSN={["0017-9310"]}, DOI={10.1016/j.ijheatmasstransfer.2011.02.066}, abstractNote={Inclinational instability developing during propagation of a filtration combustion wave in an inert porous medium is studied using two-dimensional numerical model. Stable and unstable combustion waves are generated by varying combustion parameters such as pressure, equivalence ratio, filtration velocity, effective conductivity of porous media, pellet diameter and combustor scale. The wave propagation velocity of inclinational flame is studied and compared with flat flame. The growth and reduction of inclinational instability are analyzed at different conditions. The numerical results show that a development of inclinational instability causes essential flow non-uniformity and can result in a separation of the flame front in the multiple flame zones. The limited conductive and radiant heat transfer in the solid phase, small pellet diameter of packed bed, high inlet velocity, large combustor scale and low equivalence ratio promote the instability growth. The inclinational instability is suppressed in a reciprocal combustor.}, number={15-16}, journal={INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER}, author={Zheng, Chenghang and Cheng, Leming and Saveliev, Alexei and Luo, Zhongyang and Cen, Kefan}, year={2011}, month={Jul}, pages={3642–3649} }
 @article{zheng_cheng_cen_bingue_saveliev_2012, title={Partial oxidation of methane in a reciprocal flow porous burner with an external heat source}, volume={37}, ISSN={["1879-3487"]}, DOI={10.1016/j.ijhydene.2011.11.142}, abstractNote={A reciprocal flow porous burner with an external heat source in the middle section was studied numerically to access the reactor efficiency for synthesis gas generation. The temperature and species profiles were predicted using a two temperature model with a detailed chemical mechanism. The effect of the variation of the power of the external heat source on the hydrogen and carbon monoxide yields was studied. The energy conversion efficiencies of the system with various power levels of the external heat source were evaluated. It is found that H2 and CO yields increase significantly with the addition of the external heat source due to the temperature increase in the middle section of the burner. The CO2 emissions remain small. The methane conversion ratio increases with increase of the power of the external heat source reaching 97%. The H2 and CO conversion ratios yields are nearly doubled as the power of the external heat source increases from 0 to 750 W. The cold gas energy conversion efficiency decreases as the power of the external heat source increases. At the same time, the syngas energy conversion efficiency increases from 41% to 70%, while hydrogen energy conversion efficiency increases from 28% to 46%.}, number={5}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Zheng, Chenghang and Cheng, Leming and Cen, Kefa and Bingue, Jacques P. and Saveliev, Alexei}, year={2012}, month={Mar}, pages={4119–4126} }
 @article{toledo_vergara_savelieu_2011, title={Syngas production in hybrid filtration combustion}, volume={36}, ISSN={["1879-3487"]}, DOI={10.1016/j.ijhydene.2010.11.060}, abstractNote={Rich and ultrarich combustion of butane inside porous media composed of aleatory wood pellets and alumina spheres is studied experimentally to evaluate the suitability of the concept for syngas production. Temperature, velocity, and chemical products of the combustion waves were recorded experimentally at a range of equivalence ratios from stoichiometry (φ = 1.0) to φ = 2.6. It is observed that hydrogen and carbon monoxide are dominant partial oxidation products for ultrarich hybrid combustion waves of butane and wood pellets. Syngas yield in hybrid filtration combustion is found to be essentially higher than for butane filtration combustion in an inert porous medium.}, number={6}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Toledo, Mario and Vergara, Eduardo and Savelieu, Alexei V.}, year={2011}, month={Mar}, pages={3907–3912} }
 @misc{merchan-merchan_saveliev_kennedy_jimenez_2010, title={Combustion synthesis of carbon nanotubes and related nanostructures}, volume={36}, ISSN={["0360-1285"]}, DOI={10.1016/j.pecs.2010.02.005}, abstractNote={Recently flames have emerged as a viable alternative method for the synthesis of carbon nanotubes and related nanostructures. The flame volume provides a carbon-rich chemically reactive environment capable of generating nanostructures during short residence times in a continuous single-step process. Various flame configurations, fuel types, and catalytic materials have been employed in an attempt to achieve controlled growth of multi-walled and single-walled carbon nanotubes as well as other carbon nanostructures such as nanofibers, carbon micro-trees, and whiskers. Premixed and non-premixed flames in co-flow and counterflow geometries were examined using low atmospheric and elevated pressures, various hydrocarbon fuels, oxygen enrichment, and dilution with inert gases were employed as well. Catalytic materials in the form of solid untreated supports, solid supports with pre-fabricated catalytic sites, and also in the form of aerosol have demonstrated high activity and selectivity in the growth of various nanostructures. The ability to synthesize and control carbon nanotube orientation, length, diameter, uniformity, purity, and internal morphology is essential for the fabrication of nanomechanical and electrical devices. An understanding of the growth mechanism and development of control methods such as the electric field, particle loading, and nanotemplates is critically important to address these issues. Today, flames are envisioned as the alternative technique for the synthesis of SWNTs in tons/year production scale leading to the development of related technologies such as purification and separation methods.}, number={6}, journal={PROGRESS IN ENERGY AND COMBUSTION SCIENCE}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Kennedy, Lawrence and Jimenez, Walmy Cuello}, year={2010}, month={Dec}, pages={696–727} }
 @article{merchan-merchan_saveliev_jimenez_salkar_2010, title={Flame synthesis of hybrid nanowires with carbon shells and tungsten-oxide cores}, volume={48}, ISSN={["1873-3891"]}, DOI={10.1016/j.carbon.2010.08.028}, abstractNote={We report the flame synthesis of hybrid nanowires composed of tungsten-oxide cores covered with uniform carbon shells. The synthesis is performed using 1-mm diameter tungsten probes inserted in an opposed-flow methane oxy-flame. The unique thermal and chemical composition of the generated flame tends to convert pure (99.9%) bulk tungsten into 1-D structures of unique morphology. The physical characteristics of the nanowires grown on the 1-mm diameter tungsten probe include lengths of up to 50 μm and diameters ranging from 20 to 50 nm. A two step hybrid nanowire synthesis mechanism is proposed. The initial step forms tungsten-oxide nanorods in the oxygen-rich flame region. The second step involves rapid formation of carbon shells from hydrocarbons transferred from the carbon-rich zone of the flame during the probe removal.}, number={15}, journal={CARBON}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Jimenez, Walmy Cuello and Salkar, Gautam}, year={2010}, month={Dec}, pages={4510–4518} }
 @article{zheng_cheng_saveliev_luo_cen_2011, title={Gas and solid phase temperature measurements of porous media combustion}, volume={33}, ISSN={["1540-7489"]}, DOI={10.1016/j.proci.2010.05.037}, abstractNote={This work introduces a novel method to determine gas and solid phase temperature profiles in a packed bed porous media combustor. Bare and coated thermocouple junctions were installed in the centerline of the porous combustor and the temperatures of solid phase and bare junctions were recorded simultaneously. Gas phase temperature was obtained considering the influence of flow velocity around the hot junction and the average solid temperature of the hot junction surroundings using the empirical formula for the Nusselt number based on the energy balance for the hot junction. Results show that the junction placement has a lot of influence on hot junction temperature measurement, which leads to a large uncertainty of gas temperature correction. The preheating procedure is used to reduce the effect of the junction placement. It is found that the flow velocity over junction, average solid temperature of the junction surroundings and empirical formula for the Nu number have limited influence on the gas phase temperature correction due to opposite compensating effects of these factors. The temperature profiles measured by thermocouples provide a complete temperature distribution in porous combustor, while a time-based method offers detail gas and solid temperature distributions near the reaction zone. Temperature profiles recorded for solid and gas phases vary for combustion waves propagating upstream and downstream. For all recorded regimes, the temperature gap between gas and solid has maximum and minimum points in the reaction and preheating zones, respectively.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Zheng, Chenghang and Cheng, Leming and Saveliev, Alexei and Luo, Zhongyang and Cen, Kefa}, year={2011}, pages={3301–3308} }
 @article{merchan-merchan_saveliev_cuello-jimenez_2010, title={Novel flame-gradient method for synthesis of metal-oxide channels, nanowires and nanorods}, volume={5}, ISSN={["1745-8099"]}, DOI={10.1080/17458080903464108}, abstractNote={The formation of 1D and 3D transition metal oxide (TMO) nano- and micron-size structures on molybdenum, iron and tungsten probes inserted in a counter-flow flame is studied experimentally. The unique thermal profile and chemical composition of the generated flame tends to convert almost pure bulk (99.9%) transition metal materials into 1D and 3D architectures. The synthesised Mo-, Fe- and W-oxide structures exhibit unique morphological characteristics. The application of Mo probes results in the formation of micron-size hollow and solid Mo-oxide channels. The formation of solid iron oxide nanorods is observed on iron probes. The use of W probes results in the synthesis of 1D solid carbon/metal oxide nanowires. This study confirms the existence of a common generic mechanism controlling the growth of the structures on the high-temperature probes. Metal oxide/hydroxides are formed on the probe surface exposed to the high-temperature oxidative environment. These oxides/hydroxides are further evaporated and transported by the gas flow to the low-temperature side where they are reduced to other oxide forms and deposited in the form of 1D or 3D TMO materials. This study reveals that a preferential growth at the edges of the MoO2 whisker tips leads to the development of hollow structures.}, number={3}, journal={JOURNAL OF EXPERIMENTAL NANOSCIENCE}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Cuello-Jimenez, Walmy}, year={2010}, pages={199–212} }
 @article{merchan-merchan_saveliev_jimenez_2011, title={Solid support flame synthesis of 1-D and 3-D tungsten-oxide nanostructures}, volume={33}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2010.06.122}, abstractNote={In this paper we report the growth of 1-D and 3-D tungsten-oxide nanostructures on tungsten wire probes inserted in an opposed-flow oxy-fuel flame. The probe diameter and oxygen content in the oxidizer were varied to study their influence on the growth of tungsten-oxide nanostructures. The introduction of a 1-mm diameter W probe into the flame environment with an oxidizer composition of 50%O2 + 50%N2, resulted in the formation of 1-D nanorods on the upper surface of the probe. The formation of triangular, rectangular, square, and cylindrical 3-D channels with completely hollow or semi-hollow morphology was achieved by reducing the probe diameter to 0.5 mm. Whereas, the increase of the O2 content to 100% and the employment of a 1-mm probe resulted in the growth of ribbon-like micron-sized structures. The lattice spacing of ∼0.38 nm measured for the 1-D W-oxides closely matches a monoclinic WO3 structure. X-ray photoelectron spectroscopy analysis revealed that the larger 3-D structures also consist of WO3 confirming that the chemical composition of the structures remains the same while varying the probe and flame parameters. The proposed growth mechanism states that the 3-D WO3 structures are formed through the lateral coalescence of 1-D W-oxide nanorods.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Jimenez, Walmy Cuello}, year={2011}, pages={1899–1908} }
 @misc{barcellos_souza_saveliev_kennedy_2011, title={Ultra-low-emission steam boiler constituted of reciprocal flow porous burner}, volume={35}, ISSN={["1879-2286"]}, DOI={10.1016/j.expthermflusci.2010.11.005}, abstractNote={This experimental study examined a low-emission steam boiler in which the filtration combustion technology was employed. This new boiler concept is consisted of a reciprocal flow porous burner, in which a combustion wave propagates along the reactor length. The boiler’s burner is filled up by an inert porous material, which leads to a stable burning of ultra-lean fuel/air mixtures, operating below flammability limits of conventional burners. In reciprocal filtration combustion, the reaction zone travels back and forth along the length of the burner, maintaining a typical trapezoidal temperature distribution favorable to the energy extraction. Embedding heat exchangers into the ends of the porous bed results in an alternative low-emission high-efficiency boiler. The heat re-circulation inside the porous matrix and the low degree of thermal non-equilibrium between the gas and the solid phases result in ultra-low levels of CO and NOx. Over an equivalence ratio range from 0.20 to 1.0 and a gas flow velocity range from 0.2 to 0.6 m/s, burning the technical methane, the developed prototype has reached efficiencies superior to 90% and NOx and CO emission levels lower than 1.0 and 0.5 ppm, respectively.}, number={3}, journal={EXPERIMENTAL THERMAL AND FLUID SCIENCE}, author={Barcellos, William M. and Souza, Luis Carlos E. O. and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2011}, month={Apr}, pages={570–580} }
 @article{toledo_bubnovich_saveliev_kennedy_2009, title={Hydrogen production in ultrarich combustion of hydrocarbon fuels in porous media}, volume={34}, ISSN={["1879-3487"]}, DOI={10.1016/j.ijhydene.2008.12.001}, abstractNote={Rich and ultrarich combustion of methane, ethane, and propane inside inert porous media is studied experimentally and numerically to examine the suitability of the concept for hydrogen production. Temperature, velocities, and chemical products of the combustion waves were recorded experimentally at a range of equivalence ratios from stoichiometry (φ = 1.0) to φ = 2.5, for a filtration velocity of 12 cm/s. Two-temperature numerical model based on comprehensive heat transfer and chemical mechanisms is found to be in a good qualitative agreement with experimental data. Partial oxidation products of methane, ethane, and propane (H2, CO, and C2 hydrocarbons) are dominant for ultrarich superadiabatic combustion. The maximum hydrogen yield is close to 50% for all fuels, and carbon monoxide yield is close to 80%.}, number={4}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Toledo, Mario and Bubnovich, Valeri and Saveliev, Alexei and Kennedy, Lawrence}, year={2009}, month={Feb}, pages={1818–1827} }
 @article{lock_saveliev_kennedy_2009, title={Influence of Electrode Characteristics on DC Point-to-Plane Breakdown in High-Pressure Gaseous and Supercritical Carbon Dioxide}, volume={37}, ISSN={["1939-9375"]}, DOI={10.1109/tps.2009.2018844}, abstractNote={Discharges in supercritical conditions is a new field in plasma science. The supercritical phase has distinctive properties that may allow for unique plasma processing applications. In this paper, we study plasma generation in a point-to-plane geometry in the micrometer scale. The effects of needle characteristics, including tip diameter and plane electrode surface roughness, on discharge initiation are studied. The influence of pressure, temperature, and fluid density on breakdown voltage and reduced breakdown electric field are also investigated.}, number={6}, journal={IEEE TRANSACTIONS ON PLASMA SCIENCE}, author={Lock, Evgeniya H. and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2009}, month={Jun}, pages={1078–1083} }
 @misc{merchan-merchan_saveliev_taylor_2009, title={Nucleation and growth mechanism for flame synthesis of MoO2 hollow microchannels with nanometer wall thickness}, volume={40}, ISSN={["0968-4328"]}, DOI={10.1016/j.micron.2009.07.002}, abstractNote={The growth and morphological evolution of molybdenum-oxide microstructures formed in the high temperature environment of a counter-flow oxy-fuel flame using molybdenum probes is studied. Experiments conducted using various probe retention times show the sequence of the morphological changes. The morphological row begins with micron size objects exhibiting polygonal cubic shape, develops into elongated channels, changes to large structures with leaf-like shape, and ends in dendritic structures. Time of probe–flame interaction is found to be a governing parameter controlling the wide variety of morphological patterns; a molecular level growth mechanism is attributed to their development. This study reveals that the structures are grown in several consecutive stages: material "evaporation and transportation", "transformation", "nucleation", "initial growth", "intermediate growth", and "final growth". XRD analysis shows that the chemical compositions of all structures correspond to MoO2.}, number={8}, journal={MICRON}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Taylor, Aaron M.}, year={2009}, month={Dec}, pages={821–826} }
 @article{shmelev_saveliev_kennedy_2009, title={Plasma Chemical Reactor with Exploding Water Jet}, volume={29}, ISSN={["1572-8986"]}, DOI={10.1007/s11090-009-9177-z}, number={4}, journal={PLASMA CHEMISTRY AND PLASMA PROCESSING}, author={Shmelev, Vladimir M. and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2009}, month={Aug}, pages={275–290} }
 @article{merchan-merchan_saveliev_desai_2009, title={Volumetric flame synthesis of well-defined molybdenum oxide nanocrystals}, volume={20}, ISSN={["1361-6528"]}, DOI={10.1088/0957-4484/20/47/475601}, abstractNote={Well-defined faceted inorganic Mo oxide nanocrystals are synthesized in the gas phase using a solid-fed-precursor flame synthesis method. The solid crystals have rectangular cross-section with characteristic size of 10–20 nm and with lengths ranging from 50 nm to a few hundred nanometres. A 1 mm diameter high purity Mo probe introduced in the oxygen-rich part of the flame serves as the material source. A combination of the strong temperature gradient and varying chemical species concentrations within the flame volume provides the ideal conditions for the rapid and direct formation of these unique nanocrystals. Oxidation and evaporation of MoO3 in the oxygen-rich zone are followed by reduction to MoO2 in the lower temperature, more fuel-rich zone. The MoO3 vapours formed are pushed in the direction of the gas flow and transformed into mature well-defined convex polyhedron nanocrystals bounded with six faces resembling rectangular parallelepipeds.}, number={47}, journal={NANOTECHNOLOGY}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Desai, Milind}, year={2009}, month={Nov} }
 @article{merchan-merchan_saveliev_taylor_2008, title={High rate flame synthesis of highly crystalline iron oxide nanorods}, volume={19}, ISSN={["1361-6528"]}, DOI={10.1088/0957-4484/19/12/125605}, abstractNote={Single-step flame synthesis of iron oxide nanorods is performed using iron probes inserted into an opposed-flow methane oxy-flame. The high temperature reacting environment of the flame tends to convert elemental iron into a high density layer of iron oxide nanorods. The diameters of the iron oxide nanorods vary from 10 to 100 nm with a typical length of a few microns. The structural characterization performed shows that nanorods possess a highly ordered crystalline structure with parameters corresponding to cubic magnetite (Fe3O4) with the [100] direction oriented along the nanorod axis. Structural variations of straight nanorods such as bends, and T-branched and Y-branched shapes are frequently observed within the nanomaterials formed, opening pathways for synthesis of multidimensional, interconnected networks.}, number={12}, journal={NANOTECHNOLOGY}, author={Merchan-Merchan, W. and Saveliev, A. V. and Taylor, A. M.}, year={2008}, month={Mar} }
 @article{merchan-merchan_saveliev_nguyen_2009, title={Opposed flow oxy-flame synthesis of carbon and oxide nanostructures on molybdenum probes}, volume={32}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2008.07.025}, abstractNote={The formation of carbon and metal-oxide nanostructures on molybdenum probes inserted in a counter-flow oxy-fuel flame is studied experimentally. Flame position and probe diameter were varied to achieve a controlled growth of carbon and metal-oxide nanostructures at fuel and oxygen-rich flame zones. Mo probes of 1-mm diameter were introduced in the flame at various heights, starting from the upper hydrocarbon-rich zone on the fuel side of the flame to the oxygen-rich zone on the oxidizer side. High density layers of carbon nanocoils (CNCs) and filamentous structures containing ribbon shapes and straight nanofibers were formed in the upper hydrocarbon-rich flame zone. The formation of carbon micro-trees was observed on the fuel side closer to the flame front. The structures formed in the oxidizer part of the flame were composed of molybdenum-oxides. MoO2 micron-sized channel structures were formed on the oxidizer side in the vicinity of the flame front. The micro-channels had rectangular and square-framed shapes; they were completely hollow, closed, and semi-open with a small circular cavity at their tips. The application of probes with diameters of 0.75 and 0.25 mm resulted in the formation of spectacular 3-D structures with unique and distinct morphologies.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Nguyen, Vu}, year={2009}, pages={1879–1886} }
 @article{som_ramirez_hagerdorn_saveliev_aggarwal_2008, title={A numerical and experimental study of counterflow syngas flames at different pressures}, volume={87}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2007.05.023}, abstractNote={Synthesis gas or "Syngas" is being recognized as a viable energy source worldwide, particularly for stationary power generation due to its wide availability as a product of bio and fossil fuel gasification. There are, however, gaps in the fundamental understanding of syngas combustion and emissions characteristics, especially at elevated pressures that are relevant to practical combustors. This paper presents a numerical and experimental investigation of the combustion and NOx characteristics of syngas fuel with varying composition, pressure and strain rate. Experiments were performed at atmospheric conditions, while the simulations considered different pressures. Both experiments and simulations indicate that stable non-premixed and partially premixed counterflow flames (PPFs) can be established for a wide range of syngas compositions and strain rates. Three chemical kinetic models, GRI 3.0, Davis et al., and Mueller et al. are examined. The Davis et al. mechanism is found to agree best with the experimental data, and hence used to simulate the PPF structure at different pressure and fuel composition. For the pressure range investigated, results indicate a typical double flame structure with a rich premixed reaction zone (RPZ) on the fuel side and a non-premixed reaction zone (NPZ) on the oxidizer side, with RPZ characterized by H2 oxidation, and NPZ by both H2 and CO oxidation. While thermal NO is found to be the dominant route for NO production, a reburn route, which consumes NO through NO + O + M→ NO2 + M and H + NO + M → HNO + M reactions, becomes increasingly important at high pressures. The amount of NO formed in syngas PPFs first increases rapidly with pressure, but then levels off at higher pressures. At a given pressure, the peak NO mole fraction exhibits a non-monotonic variation with syngas composition, first decreasing to a minimum value, and then increasing as the amount of CO in syngas is increased. This implies the existence of an optimum syngas composition that yields the lowest amount of NO production in syngas PPFs, and can be attributed to the combined effects of thermal and reburn mechanisms.}, number={3}, journal={FUEL}, author={Som, S. and Ramirez, A. I. and Hagerdorn, J. and Saveliev, A. and Aggarwal, S. K.}, year={2008}, month={Mar}, pages={319–334} }
 @misc{lock_merchan-merchan_d'arcy_saveliev_kennedy_2007, title={Coating of inner and outer carbon nanotube surfaces with polymers in supercritical CO2}, volume={111}, ISSN={["1932-7455"]}, DOI={10.1021/jp075684c}, abstractNote={Polymer coating and filling of carbon nanotubes (CNTs) and CNT arrays under supercritical conditions is reported in this letter. As a supercritical solvent, supercritical carbon dioxide was chosen due to its unique chemical and physical characteristics allowing effective mass transfer. Flame synthesized and commercially obtained CNTs in powder form, as well as CNT arrays of high purity and alignment were employed to study the polymer coating of inner and outer CNT surfaces. The influence of polymerization process parameters was investigated. The outcome of this work is the development of a novel, fast and efficient method for coating and filling of CNTs and CNT arrays with polymers.}, number={37}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Lock, Evgeniya H. and Merchan-Merchan, Wilson and D'Arcy, James and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2007}, month={Sep}, pages={13655–13658} }
 @article{de leo_saveliev_kennedy_zelepouga_2007, title={OH and CH luminescence in opposed flow methane oxy-flames}, volume={149}, ISSN={["1556-2921"]}, DOI={10.1016/j.combustflame.2007.01.008}, abstractNote={Emission spectroscopy is a 2-D nonintrusive diagnostic technique that offers spatially resolved data for combustion optimization and control. The UV and visible chemiluminescence of the excited radicals CH(A2Δ,B2Σ−) and OH(A2Σ+) is studied experimentally and numerically in opposed-flow diffusion flames of methane and oxygen-enriched air. The oxidized oxygen content is varied from 21 to 100% while the range of the studied strain rates spans from 20 to 40 s−1. The spectrally resolved imaging is obtained by two different methods: scattering through a grating monochromator and interposition of interference filters along the optical path. Absolute measured chemiluminescence intensities, coupled with a numerical model based on the opposed flow flame code, are used to evaluate the chemical kinetics of the excited species. The predictions of the selected model are in good agreement with the experimental data over the range of the studied flame conditions.}, number={4}, journal={COMBUSTION AND FLAME}, author={De Leo, Maurizio and Saveliev, Alexei and Kennedy, Lawrence A. and Zelepouga, Serguei A.}, year={2007}, month={Jun}, pages={435–447} }
 @article{merchan-merchan_saveliev_kennedy_2006, title={Flame nanotube synthesis in moderate electric fields: From alignment and growth rate effects to structural variations and branching phenomena}, volume={44}, ISSN={["0008-6223"]}, DOI={10.1016/j.carbon.2006.06.025}, abstractNote={The flame synthesis of carbon nanotubes (CNTs) coupled with application of moderate electric fields is studied experimentally as a means to control CNTs growth rates and morphology. The nanotubes are grown on a conductive metal-based catalytic probe positioned at the fuel side of the opposed flow oxy-flame. The probe was connected to an external voltage source to generate radial electric fields on its surface. At low applied voltages (from 0.3 to 2 V), the effect of the electric field on alignment and growth rate enhancement revealed the generation of vertically aligned carbon nanotube (VACNT) arrays with uniform distribution of CNT diameters. Further increases of the applied voltage resulted in structural modifications of the generated nanotubes. In particular, helically coiled CNTs were observed at applied voltages of ∼3 V. At higher voltages the arrays contained multi-walled CNTs with fascinating modified morphologies such as Y, T, and multi-junction patterns. Analysis of the samples generated at applied voltage of 5 V showed the presence of particle sprouting and early CNT junctions in the form of small bumps extruding from the outer surface of the CNTs. Analysis of material samples synthesized at 12 and 25 V showed the presence of fully branched CNT structures.}, number={15}, journal={CARBON}, author={Merchan-Merchan, Wilson and Saveliev, Alexel V. and Kennedy, Lawrence A.}, year={2006}, month={Dec}, pages={3308–3314} }
 @article{merchan-merchan_saveliev_kennedy_2006, title={Flame synthesis of molybdenum oxide whiskers}, volume={422}, ISSN={["0009-2614"]}, DOI={10.1016/j.cplett.2006.02.040}, abstractNote={The spectacular growth of molybdenum oxide hollow and solid whiskers with rectangular and circular cross-section is reported. The synthesis is performed using molybdenum probes inserted in an opposed-flow methane oxy-flame. The solid rectangular and circular whiskers with characteristic cross-sectional dimensions from 100 nm to 4 μm and hollow rectangular channels with wall thickness from 50 to 100 nm are grown on 1-mm diameter probes inserted at the high temperature zone on the oxidizer side of the flame front. The shape and structural parameters of grown whisker materials strongly depend on the flame position (temperature) and probe diameter. Well-defined elongated crystal structures with a large number of facets and complex symmetry were grown on the probes with a diameter of 0.25 mm.}, number={1-3}, journal={CHEMICAL PHYSICS LETTERS}, author={Merchan-Merchan, W and Saveliev, AV and Kennedy, LA}, year={2006}, month={Apr}, pages={72–77} }
 @article{lock_saveliev_kennedy_2006, title={Methanol and dimethyl sulfide removal by pulsed corona part I: Experiment}, volume={26}, ISSN={["1572-8986"]}, DOI={10.1007/s11090-006-9011-9}, number={6}, journal={PLASMA CHEMISTRY AND PLASMA PROCESSING}, author={Lock, E. H. and Saveliev, A. V. and Kennedy, L. A.}, year={2006}, month={Dec}, pages={527–542} }
 @article{bingue_saveliev_kennedy_2007, title={NO reburning in ultrarich filtration combustion of methane}, volume={31}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2006.07.257}, abstractNote={Abstract Reburning of nitrogen oxide in combustion waves formed under filtration of methane/air mixtures in a packed bed of randomly arranged inert alumina pellets is studied experimentally and numerically. Due to effective heat regeneration, the studied range of equivalence ratios spans from 0.15 to 3 covering the ultralean, lean, rich, and ultrarich regions. The data suggest strong influence of equivalence ratio on NOx emissions for pure methane/air waves due to the essential variation of the combustion chemistry. Nitrogen oxide reburning studies were performed with input concentrations of NO from 10 to 1000 ppm. Destruction and removal efficiencies above 60% were observed in ultrarich combustion waves.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Bingue, J. P. and Saveliev, A. V. and Kennedy, L. A.}, year={2007}, pages={3417–3424} }
 @article{lock_saveliev_kennedy_2006, title={Reply on the comments on "Initiation of pulsed corona discharge under Supercritical conditions" by C. H. Zhang, J. M. K. MacAlpine, and H. Akiyama}, volume={34}, ISSN={["0093-3813"]}, DOI={10.1109/tps.2006.883368}, abstractNote={Generation of plasma under supercritical conditions is of fundamental and applied interest. In this paper, the reduced electric fields required for breakdown of gaseous and supercritical carbon dioxide are comparatively analyzed for planar and coaxial cylindrical geometries. The indirect comparison of measured breakdown voltages suggests an essential change in the ionization mechanism both for uniform and nonuniform fields}, number={5}, journal={IEEE TRANSACTIONS ON PLASMA SCIENCE}, author={Lock, Evgeniya H. and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2006}, month={Oct}, pages={2467–2468} }
 @article{contarin_barcellos_saveliev_kennedy_2005, title={Energy extraction from a porous media reciprocal flow burner with embedded heat exchangers}, volume={127}, ISSN={["1528-8943"]}, DOI={10.1115/1.1844539}, abstractNote={Superadiabatic combustion in porous media allows a stable burning of ultralean methane/air mixtures, far below flammability limits. The intrinsic heat regeneration process of the porous matrix and the low degree of thermal nonequilibrium between the gas and the solid phases maintain temperatures of less than 1600 K resulting in extremely low levels of CO and NOx production. Due to the transient nature of this phenomenon, a method to confine the combustion into a practical burner has been engineered. The Reciprocal Flow Burner (RFB) is an effective and simple system to achieve this result by arranging the reaction zone to travel back and forth along the length of the burner. This ultimately results in a relatively uniform temperature profile over the central zone of the reactor. Embedding heat exchangers into the ends of the bed makes it an appealing alternative for high-efficiency, low-emission heat generation. In the present work, experimental results are presented and compared to an earlier numerical model to provide a better understanding of heat extraction from a RFB.}, number={2}, journal={JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME}, author={Contarin, F and Barcellos, WM and Saveliev, AV and Kennedy, LA}, year={2005}, month={Feb}, pages={123–130} }
 @article{silvestrini_merchan-merchan_richter_saveliev_kennedy_2005, title={Fullerene formation in atmospheric pressure opposed flow oxy-flames}, volume={30}, ISSN={["1873-2704"]}, DOI={10.1016/j.proci.2004.08.238}, abstractNote={Samples of condensable material from opposed flow diffusion flames of methane and acetylene and oxygen enriched air at atmospheric pressure were collected and analyzed by high-pressure liquid chromatography to determine the fullerene yield. High resolution transmission electron microscopy studies revealed the presence of fullerenes and well-defined carbon layers with various degrees of curvature. Results show that fullerene formation strongly increases with the acetylene content in the fuel. Increasing strain rate positively affects the fullerene content in the condensable material; higher strain rate flames favor fullerenes over soot, indicating lower fullerene consumption by soot due to lower soot concentration. If the oxygen content in the oxidizing oxygen/nitrogen mixture is increased, fullerene concentration increases due to the higher temperatures and higher precursor concentration. Similar relative variations of fullerene concentrations with flame conditions are predicted by the numerical model. However, the absolute concentrations of fullerenes are, in general, underpredicted by 4 orders of magnitude. This result can be partially attributed to uncertainties in the rate coefficients for H-abstraction and C2H2-addition. This discrepancy also suggests that other important fullerene formation pathways are to be included in the numerical model.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Silvestrini, M and Merchan-Merchan, W and Richter, H and Saveliev, A and Kennedy, LA}, year={2005}, pages={2545–2552} }
 @article{lock_saveliev_kennedy_2005, title={Initiation of pulsed corona discharge under supercritical conditions}, volume={33}, ISSN={["1939-9375"]}, DOI={10.1109/tps.2005.845302}, abstractNote={Supercritical carbon dioxide is a medium with unique properties and variety of applications in modern green chemistry. The generation of pulsed corona discharge in supercritical CO/sub 2/ is studied experimentally for point-to-plane and wire-to-plane geometries. The low breakdown voltages recorded near the critical point are attributed to peculiarities of electron kinetics in a medium characterized by high spatial inhomogeneity and enhanced cluster formation.}, number={2}, journal={IEEE TRANSACTIONS ON PLASMA SCIENCE}, author={Lock, EH and Saveliev, AV and Kennedy, LA}, year={2005}, month={Apr}, pages={850–853} }
 @article{merchan-merchan_saveliev_kennedy_2004, title={High-rate flame synthesis of vertically aligned carbon nanotubes using electric field control}, volume={42}, ISSN={0008-6223}, url={http://dx.doi.org/10.1016/j.carbon.2003.12.086}, DOI={10.1016/j.carbon.2003.12.086}, abstractNote={The electric field controlled synthesis of carbon nanomaterials on a Ni-based catalytic support positioned at the fuel side of the opposed flow oxy-flame is studied experimentally. Carbon nanomaterials formed on the probe surface are comparatively analyzed for two characteristic operational modes: a grounded probe mode and a floating probe mode. In a grounded mode a number of various carbon nanostructures are formed depending on the probe location in flame. Observed nanoforms include multi-walled carbon nanotubes (MWNTs), MWNT bundles, helically coiled tubular nanofibers, and ribbon-like coiled nanofibers with rectangular cross-section. The presence of various carbon nanoforms is attributed to the space variation of flame parameters, namely flame temperature and concentration of chemical species. It is found that the presence of an electric potential (floating mode operation) provides the ability to control the nanostructure morphology and synthesis rate. A thick layer (35–40 μm) of vertically aligned carbon nanotubes (VACNTs) is found to be formed on the probe surface in the floating potential mode. This layer is characterized by high uniformity and narrow distribution of nanotube diameters. Overall, the electric field control method demonstrates stabilization of the structure in a wide flame region while growth rate remains dependent on flame location.}, number={3}, journal={Carbon}, publisher={Elsevier BV}, author={Merchan-Merchan, Wilson and Saveliev, Alexei V. and Kennedy, Lawrence A.}, year={2004}, pages={599–608} }
 @article{contarin_saveliev_fridman_kennedy_2003, title={A reciprocal flow filtration combustor with embedded heat exchangers: numerical study}, volume={46}, ISSN={["1879-2189"]}, DOI={10.1016/s0017-9310(02)00371-x}, abstractNote={A reciprocal flow filtration combustor with embedded heat exchangers is numerically studied. In this system the combustion of methane and air mixture is stabilized in a transient porous media combustor by periodical switching the direction of the flow. Two heat exchangers are placed in the terminal sections of the porous matrix, constraining the reaction in the central insulated zone. The predicted temperature profile inside the reactor has a typical trapezoidal shape. The central plateau temperature ranges between 1300 and 1600 K as the equivalence ratio varies from 0.15 to 0.7 and the filtration velocity from 15 to 45 cm/s. The efficiency spans the range of 50–80% being higher for higher equivalence ratios and filtration velocities.}, number={6}, journal={INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER}, author={Contarin, F and Saveliev, AV and Fridman, AA and Kennedy, LA}, year={2003}, month={Mar}, pages={949–961} }
 @article{merchan-merchan_saveliev_kennedy_2003, title={Carbon nanostructures in opposed-flow methane oxy-flames}, volume={175}, ISSN={["1563-521X"]}, DOI={10.1080/714923286}, abstractNote={Carbon nanostructures formed in the opposed-flow flames of methane- and oxygen-enriched air are studied experimentally using thermophoretic sampling technique and high-resolution transmission electron microscopy (TEM). Reconstructed evolution of soot particles along the burner centerline shows the existence of two characteristic layers. The narrow layer of polydisperse precursor particles is located on the oxidizer side of the stagnation plane. The precursor particles undergo carbonization and agglomeration as they are driven to the stagnation plane forming the layer of mature soot aggregates on the fuel side of the precursor layer. High-resolution TEM imaging performed on precursors and mature soot particles reveals the presence of highly organized carbon nanostructures formed inside the tarlike amorphous condensate by carbonization process. Two characteristic structures are observed. They resemble shapes of carbon onions and carbon nanopolyhedral particles. Multiwalled carbon nanotubes (MWNTs) appeared to be present in the collected samples along with other carbon particulates. TEM imaging reveals incidence of isolated MWNTs, MWNT clusters, and clusters of MWNT with soot and nanopolyhedral particles. The nanotube growth by elongation of partially carbonized nanopolyhedral particles is considered as a possible mechanism of noncatalytic MWNT formation.}, number={12}, journal={COMBUSTION SCIENCE AND TECHNOLOGY}, author={Merchan-Merchan, W and Saveliev, AV and Kennedy, LA}, year={2003}, month={Dec}, pages={2217–2236} }
 @article{saveliev_merchan-merchan_kennedy_2003, title={Metal catalyzed synthesis of carbon nanostructures in an opposed flow methane oxygen flame}, volume={135}, ISSN={["0010-2180"]}, DOI={10.1016/s0010-2180(03)00142-1}, abstractNote={Results of an experimental study on metal-catalyzed synthesis of carbon tubular nanostructures in opposed flow flame are reported. The catalytic support made of Ni-alloy was positioned at the fuel side of the opposed flow flame formed by fuel (96%CH4+4%C2H2) and oxidizer (50%O2+50%N2) streams. The electron microscopy studies reveal the presence of highly organized carbonaceous structures with the configurations showing strong dependence on the flame location. Several typical structures were detected. These include: multiwalled nanotubes (MWNT), MWNT bundles, irregular high-density carbon nanofibers, long (up to 0.2 mm) uniform-diameter (∼100 nm) nanofibers, helical regularly coiled tubular nanofibers, and ribbon-like coiled nanofibers with rectangular cross section. Transmission electron microscopy (TEM) studies performed on long nanofibers revealed the presence of highly organized multiple (∼100) graphene layers. These layers are parallel to the nanofiber axis resembling the structure of MWNT. The TEM studies of coiled nanofibers show internal tubular structure and the presence of regular carbon lattice. The well-aligned bundles of nanotubes were examined by TEM showing tight packing of MWNTs with varying inner and outer diameters. The diversity of formed nanomaterials is attributed to the strong variation of flame properties along the flame axis including temperature, hydrocarbon and radical pool. This provides strong selectivity for formation of different nanoforms even without adjustment of catalyst properties.}, number={1-2}, journal={COMBUSTION AND FLAME}, author={Saveliev, AV and Merchan-Merchan, W and Kennedy, LA}, year={2003}, month={Oct}, pages={27–33} }
 @article{kennedy_saveliev_bingue_ridman_2002, title={Filtration combustion of a methane wave in air for oxygen-enriched and oxygen-depleted environments}, volume={29}, ISSN={["1873-2704"]}, DOI={10.1016/s1540-7489(02)80107-9}, abstractNote={In this work, filtration combustion waves formed in a packed bed of randomly arranged alumina pellets are studied experimentally. Methane is used as a fuel: the oxygen content of the oxidizer is varied from 10% to 30%. Five oxidizer compositions (10, 15, 21, 25, and 30%) are comparatively analyzed focusing on combustion temperatures, combustion wave velocities, and pollutant characteristics. The studied range of equivalence ratios spans from 0.1 to 2 covering the superadiabatic and underadiabatic combustion waves formed in ultralean, lean, rich, and ultrarich regions. It is found that combustion temperature drops with oxygen enrichment while the absolute propagation rate increases. The opposed variation of adiabatic and combustion temperatures strongly affects regimes of superadiabatic (downstream) and underadiabatic (upstream) wave propagation. For certain oxidizer compositions, the combustion tempertures more than twice exceed the adiabatic temperatures of respective homogeneous flames. To help understand the thermal and chemical structure of filtration combustion wave, two important minor products, oxides of nitrogen (NO2) and carbon monoxide (CO) emissions, were sampled from the product stream. The analysis of emission levels suggests strong influence of equivalence ratio and oxygen enrichment on CO emissions due to the variation of the combustion chemistry and contraction/extension of the reaction zone relative to the characteristic pore size. The prompt mechanism is identified as a major pathway of NO2 formation. Variation of NO with equivalence ratio in filtration combustion reproduces a characteristic bell shape pertinent to homogeneous flames, extending it to the ultralean and ultrarich regions.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Kennedy, LA and Saveliev, AV and Bingue, JP and Ridman, AA}, year={2002}, pages={835–841} }
 @article{merchan-merchan_saveliev_kennedy_fridman_2002, title={Formation of carbon nanotubes in counter-flow, oxy-methane diffusion flames without catalysts}, volume={354}, ISSN={["1873-4448"]}, DOI={10.1016/s0009-2614(02)00027-1}, abstractNote={In oxygen enriched methane diffusion flames, carbon nanotubes were discovered to be formed in the region on the fuel-rich side of the flame front at an oxygen enrichment of 50%. No catalyst was employed. An opposed flow diffusion flames with varying strain rate and oxygen content in the oxidizer stream was used. Substantial quantities of nanotube material are produced at atmospheric pressure in this continuous (non-batch) process. Thermophoretic sampling of the flame and collecting the carbon material deposited near the exhaust was done. Both confirm the growth of carbon nanotubes and other carbon clusters.}, number={1-2}, journal={CHEMICAL PHYSICS LETTERS}, author={Merchan-Merchan, W and Saveliev, A and Kennedy, LA and Fridman, A}, year={2002}, month={Mar}, pages={20–24} }
 @article{bingue_saveliev_fridman_kennedy_2002, title={Hydrogen sulfide filtration combustion: comparison of theory and experiment}, volume={26}, ISSN={["0894-1777"]}, DOI={10.1016/s0894-1777(02)00151-6}, abstractNote={Filtration combustion waves in an inert porous media were analyzed comparatively for lean and rich H2S–air mixtures. Temperature, velocity, and chemical products of the combustion wave were studied experimentally in the range of equivalence ratios from 0.1 to 5.5. Downstream (superadiabatic) wave propagation was observed for ultra-lean (ϕ⩽0.45) and ultra-rich (ϕ⩾1.7) mixtures. Upstream (underadiabatic) propagation corresponds to the range of equivalence ratios from 0.45 to 1.7. It was found that, with equal heat content, rich mixtures have higher combustion temperatures than corresponding lean mixtures. The products of partial H2S oxidation, H2, and S2 are dominant for ultra-rich superadiabatic combustion, where up to 60% of H2S was converted to S2 and H2. For lean mixtures, the dominant products were H2O, SO2, and H2SO4.}, number={2-4}, journal={EXPERIMENTAL THERMAL AND FLUID SCIENCE}, author={Bingue, JP and Saveliev, AV and Fridman, AA and Kennedy, LA}, year={2002}, month={Jun}, pages={409–415} }
 @article{beltrame_porshnev_merchan-merchan_saveliev_fridman_kennedy_petrova_zhdanok_amouri_charon_2001, title={Soot and NO formation in methane-oxygen enriched diffusion flames}, volume={124}, ISSN={["1556-2921"]}, DOI={10.1016/s0010-2180(00)00185-1}, abstractNote={NO and soot formation were investigated both numerically and experimentally in oxygen-enriched counterflow diffusion flames. Two sets of experiments were conducted. In the first set, the soot volume fraction was measured as a function of oxygen content in the oxidizer jet at constant strain rate (20 s−1). In the second set of experiments, the soot volume fraction was measured as a function of strain rate variation from 10 to 60 s−1 and at constant oxygen content on the oxidizer side. A soot model was developed based on a detailed C6 gas phase chemistry. The soot and molecular radiation were taken into account. Numerical results were verified against experimental data. The soot volume fraction was predicted with the maximum discrepancy less than 30% for all cases considered. It was found that oxygen variation significantly modified the diffusion flame structure and the flame temperature, resulting in a substantial increase of soot. The temperature increase promotes aromatics production in the fuel pyrolysis zone and changes the relative contributions of the thermal and Fenimore mechanisms into NO formation. As the strain rate increases, the residence time of incipient soot particles in the high temperature zone is reduced and the total amount of soot decreases. High concentration of soot in the flame leads to enhancement of radiant heat exchange: the reduction of temperature due to radiation was found to be between 10 and 50 K. This caused a reduction of peak NO concentrations by 20%–25%. The increase of oxygen content in the oxidizer stream resulted in a reduction of the distance between the plane of the maximum temperature and the stagnation plane.}, number={1-2}, journal={COMBUSTION AND FLAME}, author={Beltrame, A and Porshnev, P and Merchan-Merchan, W and Saveliev, A and Fridman, A and Kennedy, LA and Petrova, O and Zhdanok, S and Amouri, F and Charon, O}, year={2001}, month={Jan}, pages={295–310} }
 @article{kennedy_bingue_saveliev_fridman_foutko_2000, title={Chemical structures of methane-air filtration combustion waves for fuel-lean and fuel-rich conditions}, volume={28}, ISSN={["1873-2704"]}, DOI={10.1016/s0082-0784(00)80359-8}, abstractNote={Chemical structures of filtration combustion waves in an inert porous media were analyzed comparatively for lean and rich methane-air mixtures. Temperature, velocity, and chemical products of the combustion waves were studied experimentally in the range of equivalence ratios from 0.2 to 2.5. Downstream (superadiabatic) wave propagation was observed for ultralean ( ≤0.45) and ultrarich ( ≥1.7) mixtures. Upstream (underadiabatic) propagation corresponds to the range of equivalence ratios from 0.45 to 1.7. It was found that with the equal heat content, rich mixtures have essentially higher combustion temperatures than corresponding lean mixtures. The products of partial methane oxidation (H2, CO, and C2 hydrocarbons) are dominant for ultrarich superadiabatic combustion where up to 60% of methane is converted to CO and H2. A numerical model, based on a two-temperature approximation and detailed combustion chemistry, is developed to analyze species profiles and the combustion mechanism of the filtration waves. The model predictions for combustion temperatures and chemical products are in good agreement with experimental data. Kinetic simulation revealed the complex chemical structure of the ultrarich superadiabatic waves. It is shown that this wave is composed of an exothermic "partial oxidation" reaction zone followed by an endothermic "steam reforming" zone.}, journal={PROCEEDINGS OF THE COMBUSTION INSTITUTE}, author={Kennedy, LA and Bingue, JP and Saveliev, AV and Fridman, AA and Foutko, SI}, year={2000}, pages={1431–1438} }
 @article{zelepouga_saveliev_kennedy_fridman_2000, title={Relative effect of acetylene and PAHs addition on soot formation in laminar diffusion flames of methane with oxygen and oxygen-enriched air}, volume={122}, ISSN={["0010-2180"]}, DOI={10.1016/s0010-2180(00)00104-8}, abstractNote={Abstract The influence of the addition of acetylene and polycyclic aromatic hydrocarbons (PAHs) on soot formation was studied experimentally for nonpremixed, axisymmetric, coflowing flames of methane with oxygen and oxygen-enriched air. Four reference flames, containing 21, 35, 50, and 100% of oxygen in the oxidizer stream, were seeded with calibrated levels of acetylene, acenaphthene (C12H10), phenanthrene (C14H10), and pyrene (C16H10). It was found that all additives studied enhance soot formation in the reference flames, with the integral soot content increasing linearly with the additive concentration. The increases in the flames’ soot volume fractions induced by the addition of PAH compounds were significantly larger relative to the increase due to acetylene addition. The effect of PAH addition on soot growth became substantially stronger with oxygen enrichment of the oxidizer stream. Conversely the relative increase in soot concentration in the flames seeded with acetylene was nearly the same regardless of oxygen content in the oxidizer stream. Estimated additive-to-soot conversion ratios show high degrees of PAHs transformation to soot for all flames studied. The additive-to-soot conversion ratio for pyrene was found to be nearly 2 and remains practically constant with increase of oxygen content. Comparatively, the additive-to-soot conversion ratio for acetylene was close to 0.3 for methane/air flame and decreased with oxygen enrichment. These results suggest that conversion of PAHs to soot is controlled by a relatively fast kinetic mechanism. The conversion rate of acetylene is much slower and may involve a number of stages, including rate-limiting stage of PAHs formation.}, number={1-2}, journal={COMBUSTION AND FLAME}, author={Zelepouga, SA and Saveliev, AV and Kennedy, LA and Fridman, AA}, year={2000}, month={Jul}, pages={76–89} }
 @article{lee_megaridis_zelepouga_saveliev_kennedy_charon_ammouri_2000, title={Soot formation effects of oxygen concentration in the oxidizer stream of laminar coannular nonpremixed methane/air flames}, volume={121}, ISSN={["0010-2180"]}, DOI={10.1016/s0010-2180(99)00131-5}, abstractNote={This experimental investigation analyzes the soot formation effects of oxygen concentration in the oxidizer stream (O2 + N2) ventilating laminar jet nonpremixed methane flames. The base flame incorporates air as the oxidizer; two additional flames, with respective oxygen concentrations of 50% and 100% in the ventilating coflow, are also examined. The microstructure of soot collected from selected flame locations is determined combining thermophoretic sampling and transmission electron microscopy. A laser-light extinction technique is employed along with tomographic inversion to measure the soot volume fraction distributions within the three flames. The results indicate that soot surface growth and oxidation rates in the methane/50% oxygen flame are higher compared to the respective rates in the methane/air base flame. The rate of soot inception becomes stronger with increasing oxygen content in the oxidizer stream. Soot yields diminish with increasing oxygen concentration, as do luminous flame spatial dimensions. Soot aggregate data on the soot annulus suggest a higher degree of agglomeration under oxygen-enriched conditions. Finally, the fractal dimensions of selected soot aggregate samples are measured to be 1.64 (methane/air flame) and 1.65 (methane/50% oxygen flame), being similar to previously published values for carbonaceous soot.}, number={1-2}, journal={COMBUSTION AND FLAME}, author={Lee, KO and Megaridis, CM and Zelepouga, S and Saveliev, AV and Kennedy, LA and Charon, O and Ammouri, F}, year={2000}, month={Apr}, pages={323–333} }
 @misc{fridman_nester_kennedy_saveliev_mutaf-yardimci_1999, title={Gliding arc gas discharge}, volume={25}, ISSN={["0360-1285"]}, DOI={10.1016/s0360-1285(98)00021-5}, abstractNote={The sliding arc discharge starts at the shortest distance between the electrodes, then moves with the gas flow at a velocity of about 10 m/s and the length l of the arc column increases together with the voltage. When the length of the gliding arc exceeds its critical value lcrit, heat losses from the plasma column begin to exceed the energy supplied by the source, and it is not possible to sustain the plasma in a state of thermodynamic equilibrium. As a result, a fast transition into a non-equilibrium phase occurs. The discharge plasma cools rapidly to a gas temperature of about T0=1000 K and the plasma conductivity is maintained by a high value of the electron temperature Te=1 eV (about 11 000 K). After this fast transition, the gliding arc continues its evolution, but under non-equilibrium conditions (Te≫T0). The specific heat losses Wcrit in this regime are much smaller than in the equilibrium regime (numerically about three times less). The discharge length increases up to a new critical value of l≅3lcrit. The main part of the gliding arc power (up to 75–80%) can be dissipated in the non-equilibrium zone. After the decay of the non-equilibrium discharge, the evolution repeats from the initial break-down. This permits the stimulation of chemical reactions in regimes quite different from conventional combustion and environmental situations. It provides an alternative approach to addressing energy conservation and environmental control. In the first part of this paper, the gas discharge physics are described. The second part reviews the chemical reaction in the gliding arc plasma and some possible applications.}, number={2}, journal={PROGRESS IN ENERGY AND COMBUSTION SCIENCE}, author={Fridman, A and Nester, S and Kennedy, LA and Saveliev, A and Mutaf-Yardimci, O}, year={1999}, pages={211–231} }
 @article{mutaf-yardimci_saveliev_fridman_kennedy_1998, title={Employing plasma as catalyst in hydrogen production}, volume={23}, ISSN={["0360-3199"]}, DOI={10.1016/s0360-3199(98)00005-6}, abstractNote={A novel approach in hydrogen production via reforming of hydrocarbons that will use catalytic properties of non-equilibrium plasma gas discharge is presented. CH4/CO2 mixtures are heated to a temperature of 900°C, so that mixture will have approximately 80% of the energy required for thermal reforming. Preheated mixtures are then processed in a Pulsed Corona Discharge type plasma source and the catalytic effect of a non-equilibrium plasma is observed for promotion of hydrogen generation.}, number={12}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Mutaf-Yardimci, O and Saveliev, AV and Fridman, AA and Kennedy, LA}, year={1998}, month={Dec}, pages={1109–1111} }
 @article{drayton_saveliev_kennedy_fridman_li_1998, title={Syngas production using superadiabatic combustion of ultra-rich methane-air mixtures}, volume={27}, DOI={10.1016/s0082-0784(98)80541-9}, abstractNote={Two common methods for the production of synthesis gas (syngas) are: (1) methane partial oxidation and (2) methane steam re-forming. This paper discusses the experimental results obtained from the partial oxidation of "ultrarich," (=4), methane-air mixtures in a new type of chemical reactor based on filtration combustion. Experimental results show that the reciprocal flow burner (RFB), due to its high heat recuperation efficiency (approximately 90%), can support self-sustained combustion of ultrarich methane-air mixtures up to an equivalence ratio of 8, well beyond the conventional flammability associated with a methane-air flame in free space. For the range of equivalence ratios (2<<8) and reactor pressures (1, 3, 5 atm) investigated, the maximum experimental conversion of methane to hydrogen (65%), carbon monoxide (75%), acetylene (10%), and ethylene (8%) were observed. Parametric studies demonstrate that the maximum temperature in the combustion zone, which varies from 1100 to 1400°C, is a function of the equivalence ratio, filtration velocity, reactor pressure, and porous body diameter. Kinetic simulations reveal that methane partial oxidation occurs in a two-stage process: (1) ignition, a fast process that accounts for approximately 60% of the total hydrogen conversion relative to thermodynamic equilibrium and (2) steam reformation, a slow process where the remaining conversion of hydrogen occurs when water reacts with unburned methane.}, number={1}, journal={Symposium (International) on Combustion}, author={Drayton, M. K. and Saveliev, A. V. and Kennedy, L. A. and Fridman, A. A. and Li, Y.-E.}, year={1998}, pages={1361–1367} }
 @article{slimane_lau_khinkis_bingue_saveliev_kennedy, title={Conversion of hydrogen sulfide to hydrogen by superadiabatic partial oxidation: Thermodynamic consideration}, volume={29}, number={14}, journal={International Journal of Hydrogen Energy}, author={Slimane, R. B. and Lau, F. S. and Khinkis, M. and Bingue, J. P. and Saveliev, A. V. and Kennedy, L. A.}, pages={1471–1477} }
 @article{sobacchi_saveliev_fridman_kennedy_ahmed_krause, title={Experimental assessment of a combined plasma/catalytic system for hydrogen production via partial oxidation of hydrocarbon fuels}, volume={27}, number={6}, journal={International Journal of Hydrogen Energy}, author={Sobacchi, M. G. and Saveliev, A. V. and Fridman, A. A. and Kennedy, L. A. and Ahmed, S. and Krause, T.}, pages={635–642} }
 @article{sobacchi_saveliev_fridman_gutsol_kennedy, title={Experimental assessment of pulsed corona discharge for treatment of VOC emissions in paper and forest industry}, volume={23}, journal={Plasma Chemistry and Plasma Processing}, author={Sobacchi, M. G. and Saveliev, A. V. and Fridman, A. A. and Gutsol, A. F. and Kennedy, L. A.}, pages={347–370} }
 @article{merchan-merchan_saveliev_kennedy, title={High-rate flame synthesis of vertically aligned carbon nanotubes using electric field control}, volume={42}, journal={Carbon}, author={Merchan-Merchan, W. and Saveliev, A. V. and Kennedy, L. A.}, pages={599–604} }
 @article{bingue_saveliev_fridman_kennedy, title={Hydrogen production in ultra-rich filtration combustion of methane and hydrogen sulfide}, volume={27}, number={6}, journal={International Journal of Hydrogen Energy}, author={Bingue, J. P. and Saveliev, A. V. and Fridman, A. A. and Kennedy, L. A.}, pages={643–649} }
 @article{bingue_saveliev_kennedy, title={Optimization of hydrogen production by filtration combustion of methane by oxygen enrichment and depletion}, volume={29}, number={13}, journal={International Journal of Hydrogen Energy}, author={Bingue, J. P. and Saveliev, A. V. and Kennedy, L. A.}, pages={1365–1370} }