@misc{farkas_lloyd_keener_2007, title={Dynamic radiant food preparation methods and systems}, volume={7,307,243}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Farkas, B. E. and Lloyd, B. J. and Keener, K. M.}, year={2007} }
 @misc{keener_bashor_curtis_sheldon_kathariou_2004, title={Comprehensive review of Campylobacter and poultry processing}, volume={3}, ISSN={["1541-4337"]}, DOI={10.1111/j.1541-4337.2004.tb00060.x}, abstractNote={Campylobacter has been recognized as a leading bacterial cause of human gastroenteritis in the United States, with 40000 documented cases annually. Epidemiological data suggest that contaminated products of animal origin, especially poultry, contribute significantly to campylobacteriosis. Thus, reduction of contamination of raw poultry would have a large impact in reducing incidence of illness. Contamination occurs both on the farm and in poultry slaughter plants. Routine procedures on the farm such as feed withdrawal, poultry handling, and transportation practices have a documented effect on Campylobacter levels at the processing plant. At the plant, defeathering, evisceration, and carcass chillers have been documented to cross-contaminate poultry carcasses. Carcass washings and the application of processing aids have been shown to reduce populations of Campylobacter in the carcasses by log10 0.5 log10 1.5; however, populations of Campylobacter have been shown to enter a poultry processing plant at levels between log10 5 colony-forming units (CFU)/mL and log10 8 CFU/mL of carcass rinse. The purpose of this article is to review Campylobacter, the infection that it causes, its association with poultry, contamination sources during processing, and intervention methods.}, number={2}, journal={COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY}, author={Keener, KM and Bashor, MP and Curtis, PA and Sheldon, BW and Kathariou, S}, year={2004}, month={Apr}, pages={105–116} }
 @misc{keener_2004, title={Comprehensive review of Campylobacter and poultry processing - Response}, volume={3}, number={4}, journal={Comprehensive Reviews in Food Science and Food Safety}, author={Keener, K. M.}, year={2004}, pages={126} }
 @article{keener_anderson_curtis_foegeding_2004, title={Determination of cooling rates and carbon dioxide uptake in commercially processed shell eggs using cryogenic carbon dioxide gas}, volume={83}, ISSN={["0032-5791"]}, DOI={10.1093/ps/83.1.89}, abstractNote={The ability to rapidly cool shell eggs to 7 °C is important in the prevention of Salmonella Enteritidis (SE) growth. In addition, quality may also be maintained longer from rapid cooling of shell eggs. A commercial cryogenic CO2 egg cooling unit was designed and installed in a commercial egg processing facility. This unit was installed on a packer head to rapidly cool eggs individually prior to packaging. The objective of this study was to determine cooling rates and CO2 gas changes that result from rapidly cooling eggs using this commercial cryogenic egg cooling system and subsequent storage for 15 wk. Results indicated that cryogenic CO2 cooling quickly cooled shell eggs in approximately 45 min, whereas traditional cooling required from 19 to 116 h. CO2 uptake into the albumen was greater in cryogenically cooled eggs (2.11 mg/g) than in traditionally cooled eggs (1.81 mg/g) immediately after processing. No differences were observed in albumen CO2 content after 2 wk of storage; at 10 wk statistically greater CO2 content remained in the cryogenically cooled eggs (1.75 mg/g) compared with the traditionally cooled eggs (1.60 mg/g). These results suggest that a large amount of CO2 enters the egg during the cryogenic cooling process but is quickly lost during storage. Beyond 10 wk of storage, the albumen CO2 content in cryogenically cooled eggs was higher than in the traditionally cooled eggs suggesting chemical changes may have occurred in the albumen.}, number={1}, journal={POULTRY SCIENCE}, author={Keener, KM and Anderson, KE and Curtis, PA and Foegeding, JB}, year={2004}, month={Jan}, pages={89–94} }
 @article{bottcher_keener_munilla_williams_schiffman_2004, title={Dust and odor emissions from tunnel ventilated swine buildings in North Carolina and comparison of different odor evaluation methods}, volume={20}, DOI={10.13031/2013.16064}, abstractNote={Tunnel ventilation of swine buildings conveys odorous dust and gases out of the production buildings. Measurement of dust and odor levels and other environmental parameters is necessary for characterizing emissions and evaluating control options. During evaluations of odor control systems, measurements of dust and odor levels in building inlet and exhaust air were obtained. Odor and dust levels were consistent with data obtained in other states and Europe. Odor concentrations and emission rates were based on odor measurements from the Duke University Taste and Smell Laboratory at several dilution levels, as well as a calibration curve for odor panelists based on swine manure odor. The computed odor concentration based on measurements over a range of dilutions was greater than the predicted odor concentration based on the calibration curve, for two field visits. This result may be due to odorous dust particles increasing odor persistence above that of vaporous odorants from swine manure. Odor measurements were also obtained using headspace sampling of unaspirated and aspirated cotton swatches. Aspirating the swatches increased odor intensity compared to unaspirated swatches and improved correlation with air sample odor intensities.}, number={3}, journal={Applied Engineering in Agriculture}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2004}, pages={343–347} }
 @article{bashor_curtis_keener_sheldon_kathariou_osborne_2004, title={Effects of carcass washers on Campylobacter contamination in large broiler processing plants}, volume={83}, ISSN={["1525-3171"]}, DOI={10.1093/ps/83.7.1232}, abstractNote={Campylobacter, a major foodborne pathogen found in poultry products, remains a serious problem facing poultry processors. Campylobacter research has primarily focused on detection methods, prevalence, and detection on carcasses; limited research has been conducted on intervention. The aim of this study was to assess the effectiveness of carcass washing systems in 4 large broiler-processing plants in removing Campylobacter species. Washing systems evaluated included combinations of inside/outside carcass washers and homemade cabinet washers. Processing aids evaluated were trisodium phosphate (TSP) and acidified sodium chlorite (ASC). The washer systems consisted of 1 to 3 carcass washers and used from 2.16 to 9.73 L of water per carcass. The washer systems used chlorinated water with 25 to 35 ppm of total chlorine. These washer systems on average reduced Campylobacter populations by log 0.5 cfu/mL from log 4.8 cfu/mL to log 4.3 cfu/mL. Washer systems with TSP or ASC reduced Campylobacter populations on average by an additional log 1.03 to log 1.26, respectively. Total average reductions in Campylobacter populations across the washer system and chill tank were log 0.76 cfu/mL. Washer systems that included antimicrobial systems had total average reductions in Campylobacter populations of log 1.53 cfu/mL. These results suggest that carcass washer systems consisting of multiple washers provide minimal reductions in Campylobacter populations found on poultry in processing plants. A more effective treatment of reducing Campylobacter populations is ASC or TSP treatment; however, these reductions, although significant, will not eliminate the organism from raw poultry.}, number={7}, journal={POULTRY SCIENCE}, author={Bashor, MP and Curtis, PA and Keener, KM and Sheldon, BW and Kathariou, S and Osborne, JA}, year={2004}, month={Jul}, pages={1232–1239} }
 @article{keener_irudayaraj_ngadi_rosenstrater_payne_2004, title={For undergrads: A food and bioprocess engineering vision}, volume={11}, ISBN={1076-3333}, number={6}, journal={Resource, Engineering & Technology for a Sustainable World}, author={Keener, K. and Irudayaraj, J. and Ngadi, M. O. and Rosenstrater, K. A. and Payne, F. A.}, year={2004}, pages={5} }
 @article{sabliov_farkas_keener_curtis_2002, title={Cooling of shell eggs with cryogenic carbon dioxide: a finite element analysis of heat transfer}, volume={35}, DOI={10.1006/fstl.2002.0915}, abstractNote={Cryogenic carbon dioxide cooling of shell eggs was simulated using an axisymmetric unsteady state finite element heat transfer model. The egg was assumed to be a composite system of elliptical shape, consisting of yolk, albumen, air cell, and shell, each isotropic. An enthalpy formulation of the heat transfer problem was used to account for ice formation and growth in the region between the albumen and the shell during cooling. Simulated temperature profiles were compared with analytical and observed data and showed good agreement. The numerical simulation was used to gain an understanding of the two processes encompassed by cryogenic cooling, rapid cooling and equilibration.}, number={7}, journal={Food Science & Technology = Lebensmittel-Wissenschaft & -Technologie}, author={Sabliov, C. M. and Farkas, B. E. and Keener, K. M. and Curtis, P. A.}, year={2002}, pages={568–574} }
 @article{jones_tharrington_curtis_anderson_keener_jones_2002, title={Effects of cryogenic cooling of shell eggs on egg quality}, volume={81}, ISSN={["0032-5791"]}, DOI={10.1093/ps/81.5.727}, abstractNote={This study was conducted to investigate the effects of cryogenic cooling on shell egg quality. Gaseous nitrogen (GN), liquid nitrogen (LN), and gaseous carbon dioxide (GC) were utilized to rapidly cool eggs in a commercial egg processing facility and were compared to traditional cooling (TC). A modified food freezer was attached to existing egg processing equipment in order to expose eggs to the selected cryogen. In Experiment 1, eggs were treated with GN, LN, and TC then stored and tested over 10 wk. Experiment 2 eggs were treated (GC and TC) and evaluated for 12 wk. Quality factors that were measured included Haugh units, vitelline membrane strength and deformation at rupture, and USDA shell egg grades for quality defects. Haugh unit values were greater for cryogenically treated eggs as compared to traditionally cooled eggs (Experiment 1: 73.27, GN; 72.03, LN; and 71.4, TC and Experiment 2: 74.42, GC and 70.18, TC). The percentage of loss eggs in the GN treatment was significantly (P < 0.01) greater than those of the LN and TC treatments. Vitelline membrane strength was greater for the cryogenically cooled eggs versus traditional processing. Vitelline membrane breaking strength decreased over storage time. Vitelline membrane deformation at rupture was significantly (P < 0.05) greater for the cryogenically cooled eggs compared to the traditional eggs in each experiment. Use of the technology could allow for egg quality to be maintained for a longer time, which could increase international markets and potentially lead to extended shelf lives.}, number={5}, journal={POULTRY SCIENCE}, author={Jones, DR and Tharrington, JB and Curtis, PA and Anderson, KE and Keener, KM and Jones, FT}, year={2002}, month={May}, pages={727–733} }
 @article{keener_zhang_bottcher_munilla_2002, title={Evaluation of thermal desorption for the measurement of artificial swine odorants in the vapor phase}, volume={45}, DOI={10.13031/2013.11063}, abstractNote={Quantification of odorants from animal production facilities is difficult. The current technique is to collect air
samples in Tedlar bags and quantify odor using a trained olfactory panel. In this approach, relative differences between
samples can be determined, but further quantification of odorants is limited. An alternative approach is to quantify odorants
in air emissions using sorbent tubes. A sorbent tube is a glass tube packed with a specific adsorbent material (Tenax TA,
Carboxen 1000, Carbosieve SIII, etc.) and has been used to collect volatiles and quantify emissions from various industrial
sources. Each adsorbent has a limited range of chemical selectivity. Limited applications of sorbent tubes with single or dual
adsorbents have been used to measure odorant emissions from animal production facilities. 
In this study, tri–packed sorbent tubes and Tedlar bags were compared in characterizing 19 major odorants found in
artificial swine odor. The sorbent tubes were packed with Tenax TA, Carboxen 1000, and Carbosieve SIII. The artificial swine
odor was directly desorbed onto the tri–packed sorbent tube. For comparison, a 10–L Tedlar bag was filled with nitrogen gas
and artificial swine odor. The Tedlar bag was then desorbed onto the tri–packed sorbent tube. The sorbent tube was then
thermally desorbed into a gas chromatography (GC) system with a flame ionization detector (FID) for quantification. The
tri–packed sorbent tube demonstrated recoveries greater than 74% and detection limits less than 0.4 ng for all 19 odorants.
Thus, a tri–packed sorbent tube may provide an analytical method to measure low concentrations of major odorants found
in air emissions from swine production facilities. Tedlar bags showed limited recoveries of some odorants, less than 12% for
indole and skatole. In addition, Tedlar bags immediately sampled after three flushings with nitrogen emitted 3.50 ng L–1 hr–1
of acetic acid (~35% above background levels) and 2.13 ng L–1 hr–1 phenol (~27% above background levels). These results
suggest that air samples collected in Tedlar bags may bias olfactory analysis.}, number={5}, journal={Transactions of the ASAE}, author={Keener, K. M. and Zhang, J. and Bottcher, R. W. and Munilla, R. D.}, year={2002}, pages={1579–1584} }
 @article{sabliov_boldor_keener_farkas_2002, title={Image processing method to determine surface area and volume of axi-symmetric agricultural products}, volume={5}, ISSN={["1094-2912"]}, DOI={10.1081/JFP-120015498}, abstractNote={ABSTRACT An image processing based method was developed to measure volume and surface area of ellipsoidal agricultural products such as eggs, lemons, limes, and peaches. The method assumes that each product has an axi-symmetric geometry and is a sum of superimposed elementary frustums of right circular cones. The product volume and surface area are calculated as the sum of the volumes and surface areas of individual frustums using Matlab®. The dimensions of individual frustums are determined from a digitized picture of the product acquired by a Charged Coupled Device (CCD) camera and processed in Adobe Photoshop®. The volumes and surface areas computed showed good agreement with analytical and experimental results. The developed method proved to be accurate, precise, and easy to use.}, number={3}, journal={INTERNATIONAL JOURNAL OF FOOD PROPERTIES}, author={Sabliov, CM and Boldor, D and Keener, KM and Farkas, BE}, year={2002}, pages={641–653} }
 @article{sabliov_farkas_keener_curtis_2002, title={Parametric analysis of cryogenic carbon dioxide cooling of shell eggs}, volume={81}, ISSN={["1525-3171"]}, DOI={10.1093/ps/81.11.1758}, abstractNote={Parametric analysis of cryogenic cooling of shell eggs was performed using finite element analysis. Two cooling temperatures (-50 and -70 C), three cooling convective heat transfer coefficients (20, 50, and 100 W/ m2K), two equilibration temperatures (7 and 25 C), and two equilibration heat transfer coefficients (0 and 20 W/ m2K) were considered in the analysis. Lower temperatures and higher cooling convective heat transfer coefficients resulted in higher cooling rates and lower final egg temperatures. A chart and equation were developed to identify combinations of processing parameters to yield the desired egg temperature (7 C) at the end of adiabatic equilibration. Results show that a cooling time of 8.2 min was required to reach a final egg temperature of 7 C for a cooling temperature of -50 C and a convective heat transfer coefficient of 20 W/m2K. The cooling time decreased to 2 min when the convective heat transfer coefficient increased to 100 W/m2K, at a cooling temperature of -50 C. Processing at -70 C and 20 W/m2K, required 5.3 min to reach a final temperature of 7 C. At a higher convective heat transfer coefficient (100 W/m2K) and -70 C, a processing time of 1.3 min was sufficient to reach the target temperature of 7 C. The results may be used as a reference in process or equipment design for shell egg cooling in cryogenic CO2.}, number={11}, journal={POULTRY SCIENCE}, author={Sabliov, CM and Farkas, BE and Keener, KM and Curtis, PA}, year={2002}, month={Nov}, pages={1758–1765} }
 @article{heber_ni_haymore_duggirala_keener_2001, title={Air quality and emission measurement methodology at swine finishing buildings}, volume={44}, DOI={10.13031/2013.7013}, abstractNote={Reliable measurements of air quality and emissions at large livestock buildings with inherently large spatial andtemporal variations of pollutant concentrations are relatively difficult and expensive. Appropriate methodologies for suchmeasurements are not readily apparent and techniques and strategies vary widely. Several important technical issues needto be addressed by an air pollutant emission measurement plan. This article describes comprehensive field measurements ofindoor air quality and air pollutant emissions at eight commercial swine finishing buildings.<br><br>The objective of the field test was to evaluate the effect of a manure additive on concentration and emission of ammonia,hydrogen sulfide, and odor. Continuous measurements of gases, ventilation rate, building static pressure, inside and outsidetemperature and humidity, and wind speed and direction were conducted at four naturallyventilated buildings and fourmechanicallyventilated buildings. Air was pumped continuously from inside each building into airsampling manifolds. Oneair stream was drawn from beneath the floor to assess pit headspace air concentrations. Another air stream was drawn fromventilation exhaust points to assess inside gas concentrations and building emission rates. Gas analyzers were switchedbetween sampling manifolds on 10 to 15min sampling intervals. Ammonia was measured with chemiluminescence NOxanalyzers after conversion to nitric oxide. Hydrogen sulfide was converted to sulfur dioxide and measured withpulsedfluorescence, sulfur dioxide analyzers. Odor samples were collected in bags and evaluated using olfactometry. Gasand odor emission rates were determined by multiplying mean gas concentrations in the exhaust air by ventilation airflowrates. Ventilation rates of naturallyventilated buildings were estimated using sensible heat and carbon dioxide balances.Ventilation rates of mechanicallyventilated buildings were determined by monitoring wall fan operation and directlymeasuring airflow of some variablespeed pit fans with fullsize impeller anemometers. Labor and equipment requirements,pitfalls, problems, and solutions to problems of field studies are discussed. Several recommendations for future studies of thistype were developed based on experience gained during this measurement campaign.}, number={6}, journal={Transactions of the ASAE}, author={Heber, A. J. and Ni, J. Q. and Haymore, B. L. and Duggirala, R. K. and Keener, K. M.}, year={2001}, pages={1765–1778} }
 @article{oehrl_keener_bottcher_munilla_connelly_2001, title={Characterization of odor components from swine housing dust using gas chromatography}, volume={17}, DOI={10.13031/2013.6911}, abstractNote={A method was developed for the determination of odor–causing compounds in swine housing dust. Dust samples
were extracted with methanol while heating to 60


C. After partitioning, the methanol containing the compounds of interest
was analyzed by gas chromatography (GC) using flame ionization detection (FID). Efficiency of extraction was proven by
spike recovery. Samples of dust from houses treated with various odor–controlling systems were compared to untreated
controls. This method allowed for relative comparisons of odor compounds that could be used to evaluate the effectiveness
of engineering systems to control dust and odor.}, number={5}, journal={Applied Engineering in Agriculture}, author={Oehrl, L. L. and Keener, K. M. and Bottcher, R. W. and Munilla, R. D. and Connelly, K. M.}, year={2001}, pages={659–661} }
 @article{keener_lacrosse_babson_2001, title={Chemical method for determination of carbon dioxide content in egg yolk and egg albumen}, volume={80}, ISSN={["0032-5791"]}, DOI={10.1093/ps/80.7.983}, abstractNote={The safety, quality, and shelf life of shell eggs is a function of carbon dioxide content. A commercial process was recently developed for rapidly cooling shell eggs by using cryogenic CO2. The benefit of this new process over existing cooling processes is that the CO2 addition during cryogenic cooling provides additional safety and quality enhancements. In order for these benefits to be fully developed into a process that can be adopted by the egg industry, and thus realized by the consumer, the amount of CO2 absorbed by the egg during this process needs to be quantified. Because the albumen pH of rapidly cooled eggs was reduced to pH <6.5, existing titrametric methods were not adequate for determining CO2 content. They did not prevent CO2 loss during neutralization. A simple and accurate method for determining CO2 content in acidified egg albumen and yolk samples was developed. This method involves the liberation of CO2 from an acidified egg sample into a standardized, dilute sodium hydroxide solution inside a sealed jar. The egg sample and a small beaker containing the standardized sodium hydroxide solution are placed in a glass jar and sealed. Next, a concentrated acid phosphate solution is injected through a rubber septum in the cap of the jar onto the egg sample, while avoiding contact with the sodium hydroxide solution. The sample is then stored at 37 C for 24 h. During this storage period, the carbon dioxide is released from the egg sample and is absorbed into the sodium hydroxide solution. Afterwards, the dilute sodium hydroxide solution is removed and titrated to the phenolphthalein endpoint using a dilute, standardized hydrochloric acid solution. The amount of hydrochloric acid solution required for neutralization can be directly related to CO2 content in the sample.}, number={7}, journal={POULTRY SCIENCE}, author={Keener, KM and LaCrosse, JD and Babson, JK}, year={2001}, month={Jul}, pages={983–987} }
 @article{keener_2000, title={Air quality intervention strategies in the processing plant: A systems approach}, ISBN={0962768267}, journal={Proceedings, 2000 National Poultry Waste Management Symposium}, publisher={Auburn University, AL : National Poultry Waste Management Symposium Committee}, author={Keener, K. M.}, year={2000}, pages={311} }
 @article{parbst_keener_heber_ni_2000, title={Comparison between low-end discrete and high-end continuous measurements of air quality in swine buildings}, volume={16}, DOI={10.13031/2013.5377}, abstractNote={Temperature and gas (ammonia, carbon dioxide, and hydrogen sulfide) concentrations were measured withportable instrumentation and compared with measurements taken by a continuous system with automated benchtop gasanalyzers in four tunnel-ventilated commercial swine finishing buildings. Measurements of ammonia and hydrogen sulfideconcentrations did not differ significantly with respect to equipment used. However, carbon dioxide concentrations weredifferent, and on average the portable instrument measurements were 40% lower during summer and 29% lower duringwinter. These discrepancies suggest that carbon dioxide spatial variation may be significant. Conscientiously operatedportable instrumentation can be used to effectively characterize air quality parameters within the animal environment.}, number={6}, journal={Applied Engineering in Agriculture}, author={Parbst, K. E. and Keener, K. M. and Heber, A. J. and Ni, J. Q.}, year={2000}, pages={693–699} }
 @article{bottcher_munilla_baughman_keener_2000, title={Designs for windbreak walls for mitigating dust and odor emissions from tunnel ventilated swine buildings}, ISBN={1892769107}, DOI={10.13031/2013.83}, abstractNote={Although windbreak walls have traditionally been applied to reduce ground-level wind speeds and enhance snow deposition, windbreak walls have also recently been placed downwind of animal buildings in efforts to control emissions of dust and odors. In particular, windbreaks placed near exhaust fans on tunnel-ventilated livestock and poultry buildings appear promising, primarily because the air jets issuing from the exhaust fans are diverted upward. This effect promotes mixing of the odorous, dusty airflow with the wind passing over the building, so that the plumes of air pollutants originating from the fans are made larger (extend higher). Thus it is reasonable to expect that in some wind conditions the aerial concentration of odorous vapors, dust, and other air pollutants in the breathing space of downwind neighbors will be reduced by improvement in air mixing at the emission sources (the fans). Windbreak structures may either be designed to withstand the same wind speeds as the buildings and be insured with the buildings, or lower wind speeds at reduced cost. Relevant design considerations and low-cost designs using UV-resistant tarpaulin or plastic material, roofing, or wood fastened to anchored pipe frames or posts are discussed. If the windbreaks are not designed for maximum design wind speeds, a method of ensuring non-catastrophic failure is needed, such as breakaway ties fastening material to frames. The location of the windbreak affects the diversion of airflow from exhaust fans. Further modeling and field evaluations are needed to determine beneficial and potential adverse effects of fan plume deflection. Observations of windbreak action in several locations suggest that the windbreaks should be placed two to four fan diameters downwind from the fans to deflect fan airflow without back pressures, and extend high enough to fully intercept the plumes of airflow issuing from the fans (e.g. 4 m high for typical buildings).}, journal={Swine housing : proceedings of the first international conference : October 9-11, 2000, Des Moines, Iowa}, publisher={St. Joseph, Mich. : American Society of Agricultural Engineers}, author={Bottcher, R. W. and Munilla, R. D. and Baughman, G. R. and Keener, K. M.}, year={2000}, pages={174} }
 @article{bottcher_keener_munilla_williams_schiffman_2000, title={Dust and odor emissions from tunnel ventilated swine buildings in North Carolina}, ISBN={1892769123}, journal={Air pollution from agricultural operations : proceedings of the 2nd international conference, October 9-11, 2000, Des Moines, Iowa}, publisher={St. Joseph, Mich. : American Society of Agricultural Engineers}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2000}, pages={196} }
 @article{keener_lacrosse_farkas_curtis_anderson_2000, title={Gas exchange into shell eggs from cryogenic cooling}, volume={79}, ISSN={["0032-5791"]}, DOI={10.1093/ps/79.2.275}, abstractNote={The gas composition of the air cell in a shell egg is influenced by heating from egg washing and candling and the method of cooling and storage. This study found that N2 gas (-122 C), CO2 gas (-45 C), and cold air (-15 C) could be used to rapidly cool shell eggs from 47.7 C to 7 C in 30 min or less. These results suggest that the gas composition of the air cell in shell eggs can be significantly modified using N2 cooling and CO2 cooling. Commercial field studies have shown that these modifications, which take place during cryogenic cooling, can significantly reduce microbial levels and increase shelf life of shell eggs. Storage in a modified atmosphere environment further enhanced these changes. It was found that the CO2 concentration in the air cell of a shell egg can be increased from 0.04 to 48% by CO2 cooling and storage in a CO2 environment.}, number={2}, journal={POULTRY SCIENCE}, author={Keener, KM and Lacrosse, JD and Farkas, BE and Curtis, PA and Anderson, KE}, year={2000}, month={Feb}, pages={275–280} }
 @article{bottcher_keener_munilla_williams_schiffman_2000, title={Scent of a swine building: Tunnel ventilation problems test engineers' ingenuity}, volume={7}, ISBN={1076-3333}, number={10}, journal={Resource, Engineering & Technology for a Sustainable World}, author={Bottcher, R. W. and Keener, K. M. and Munilla, R. D. and Williams, C. M. and Schiffman, S. S.}, year={2000}, pages={13} }
 @article{keener_lacrosse_curtis_anderson_farkas_2000, title={The influence of rapid air cooling and carbon dioxide cooling and subsequent storage in air and carbon dioxide on shell egg quality}, volume={79}, ISSN={["0032-5791"]}, DOI={10.1093/ps/79.7.1067}, abstractNote={This study examined the effect of rapid cooling with air and CO2 on shell egg quality over 14 wk. The 240 fresh eggs were initially heated to 47 C for 24 h in an incubator, cooled using rapid air cooling or CO2 cooling, and then stored in air or CO2 in 250-mL jars for 14 wk. The CO2 levels were recorded of the jar atmosphere, of the egg air cell, and of the egg albumen. The Haugh units of each egg, pH, and of albumen from five eggs per group were also recorded. Haugh units are a logarithmic, empirical relationship between albumen height and egg weight (Stadelman, 1995). Haugh units for the control eggs averaged 70.8 over 10 wk of the study. The control eggs were of such poor quality that they could not be sampled after 10 wk. The air-cooled and CO2-stored eggs averaged 70.3 Haugh units over the 14-wk storage period; however, the egg quality significantly deteriorated after 10 wk. The CO2-cooled and CO2-stored eggs averaged 75.9 Haugh units over the 14 wk study, with no observable decrease in quality. Rapid air-cooling produces a lower quality egg than rapid cooling with CO2. Subsequent storage of rapidly air-cooled eggs in C02 may increase shelf life, but Haugh units were not statistically different from rapid air-cooled eggs. CO2-cooling and subsequent storage in CO2 increased Haugh units. The shelf life of shell eggs could be extended to greater than 14 wk when the eggs were CO2-cooled and CO2-stored.}, number={7}, journal={POULTRY SCIENCE}, author={Keener, KM and LaCrosse, JD and Curtis, PA and Anderson, KE and Farkas, BE}, year={2000}, month={Jul}, pages={1067–1071} }
 @article{keener_stroshine_nyenhuis_1999, title={Evaluation of low field (5.40-MHz) proton magnetic resonance measurements of D-w and T-2 as methods of nondestructive quality evaluation of apples}, volume={124}, number={3}, journal={Journal of the American Society for Horticultural Science}, author={Keener, K. M. and Stroshine, R. L. and Nyenhuis, J. A.}, year={1999}, pages={289–295} }
 @article{keener_stroshine_nyenhuis_1997, title={Proton magnetic resonance measurement of self-diffusion coefficient of water in sucrose solutions, citric acid solutions, fruit juices, and apple tissue}, volume={40}, DOI={10.13031/2013.21402}, abstractNote={Proton magnetic resonance (1H-MR) studies were conducted on sucrose solutions, aqueous solutions, filteredapple juice, unfiltered apple juice, red grape juice, orange juice, and tissue from Red Delicious, Golden Delicious, andGranny Smith apples. The Pulse Field Gradient Spin-Echo (PFGSE) technique was used to measure the self-diffusioncoefficient of water (Dw) and the Carr-Purcell-Meiboom-Gill (CPMG) technique was used to measure spin-spinrelaxation (T2). The 1H-MR system operated at 5.40 MHz and used a permanent magnet with a field strength of 0.1256 T.Two different quadrupole gradient coil probes were built to generate gradient pulses of 0.058 T/m and 0.108 T/m. The Dwmeasurements were correlated with titratable acids, insoluble solids, and refractometer measurements of percent solublesolids. The results give insight into factors that influence Dw in fruits and vegetables. The Dw increase with increasingtemperature depends on soluble solids level. Dw is influenced by pH and titratable acids only in proportion to theircontribution to soluble solids levels. However, T2 showed a dependence on pH, buffering, soluble solids, and insolublesolids. In the apple tissue, Granny Smith was the only variety that showed a statistical dependence for Dw on bothrefractometer brix and percent insoluble solids (R2 = 0.98).}, number={6}, journal={Transactions of the ASAE}, author={Keener, K. M. and Stroshine, R. L. and Nyenhuis, J. A.}, year={1997}, pages={1633–1641} }