@article{zhao_ramirez_siegford_gan_li_berckmans_burns_2024, title={Field Implementation of Precision Livestock Farming: Selected Proceedings from the 2nd U.S. Precision Livestock Farming Conference}, url={https://www.mdpi.com/2076-2615/14/7/1128}, DOI={10.3390/ani14071128}, abstractNote={Precision Livestock Farming (PLF) involves the real-time monitoring of images, sounds, and other biological, physiological, and environmental parameters to assess and improve animal health and welfare within intensive and extensive production systems [...].}, journal={Animals}, author={Zhao, Yang and Ramirez, Brett C. and Siegford, Janice and Gan, Hao and Li, Lingjuan and Berckmans, Daniel and Burns, Robert}, year={2024}, month={Apr} }
 @article{uemura_regmi_grimes_wang-li_shah_2023, title={Low Airspeed Impacts on Tom Turkey Response to Moderate Heat Stress}, volume={5}, ISSN={["2624-7402"]}, url={https://www.mdpi.com/2624-7402/5/4/121}, DOI={10.3390/agriengineering5040121}, abstractNote={Heat stress is a concern for turkeys in naturally ventilated houses. Chamber and room studies were used to assess heat stress at moderate temperatures (<25 °C) and low airspeeds on grown tom turkeys. In the chamber study, four ventilation rates × two temperatures (thermal comfort and thermal stress, 11 °C above thermal comfort) were applied to 13- to 19-week birds. Very small differences in airspeeds among the four treatments masked subcutaneous, cloacal, and infrared (IR) temperature differences at both temperatures. In the room study, four ventilation rates (0.07 m3·min−1·kg−1 or 100%, 75%, 50%, and 30% or Control) were applied to 21-week toms housed at < 23 °C. The Control treatment had significantly higher whole-body and head temperatures vs. the other treatments. Only 100% had higher weight gain vs. 50%; hematology was unaffected by treatment. Higher ventilation rates reduced heat stress due to lower room temperatures, not airspeed differences, which were very low. The low-cost IR camera detected a heat stress difference ≥ 0.8 °C, corresponding to wind chill of 0.8 °C due to an airspeed of 0.8 m·s−1 vs. still air on the USDA broiler wind chill curve. Machine vision combined with IR thermography could alleviate real-time poultry heat stress.}, number={4}, journal={AGRIENGINEERING}, author={Uemura, Derek and Regmi, Prafulla and Grimes, Jesse and Wang-Li, Lingjuan and Shah, Sanjay}, year={2023}, month={Dec}, pages={1971–1988} }
 @article{akter_cheng_west_liu_qian_zou_classen_cordova_oviedo_wang-li_2022, title={Impacts of Air Velocity Treatments under Summer Condition: Part I—Heavy Broiler’s Surface Temperature Response}, volume={12}, ISSN={2076-2615}, url={http://dx.doi.org/10.3390/ani12030328}, DOI={10.3390/ani12030328}, abstractNote={Simple Summary The surface temperature variation of heavy broilers (42–61 d age) under heat stress is an important indicator of thermal comfort, but it is not well studied and reported yet. This study examined the variation of surface temperatures of broilers through two dynamic air velocity treatments under hot summer conditions. It was discovered that the surface temperatures varied over age, daytime, and environmental factors (air temperature, relative humidity, and temperature humidity index). A simple linear regression model to predict the surface temperature of heavy broilers was developed. The findings from this study will enhance knowledge to understand the broilers’ responses under heat stress, which will be helpful in providing necessary management decisions to create a comfortable thermal environment. Abstract Heavy broilers exposed to hot summer conditions experience fluctuations in surface temperatures due to heat stress, which leads to decreased performance. Maintaining a bird’s homeostasis depends on several environmental factors (temperature, relative humidity, and air velocity). It is important to understand the responses of birds to environmental factors and the amount of heat loss to the surrounding environment to create thermal comfort for the heavy broilers for improved performances and welfare. This study investigates the variation in surface temperatures of heavy broilers under high and low air velocity treatments. Daytime, age and bird location’s effect on the surface temperature variation was also examined. The experiment was carried out in the poultry engineering laboratory of North Carolina State University during summers of 2017, 2018, and 2019 as a part of a comprehensive study on the effectiveness of wind chill application to mitigate heat stress on heavy broilers. This live broiler heat stress experiment was conducted under two dynamic air velocity treatments (high and low) with three chambers per treatment and 44 birds per chamber. Surface temperatures of the birds were recorded periodically through the experimental treatment cycles (flocks, 35–61 d) with infrared thermography in the morning, noon, evening, and nighttime. The overall mean surface temperature of the broilers under two treatments was found to be 35.89 ± 2.37 °C. The variation in surface temperature happened due to air temperature, thermal index, air velocity, bird’s age, daytime, and position of birds inside the experimental chambers. The surface temperatures were found lower under high air velocity treatment and higher under low air velocity treatment. During the afternoon time, the broilers’ surface temperatures were higher than other times of the day. It was also found that the birds’ surface temperature increased with age and temperature humidity indices. Based upon the experimental data of five flocks, a simple linear regression model was developed to predict surface temperature from the birds’ age, thermal indices, and air velocity. It will help assess heavy broilers’ thermal comfort under heat stress, which is essential to provide a comfortable environment for them.}, number={3}, journal={Animals}, publisher={MDPI AG}, author={Akter, Suraiya and Cheng, Bin and West, Derek and Liu, Yingying and Qian, Yan and Zou, Xiuguo and Classen, John and Cordova, Hernan and Oviedo, Edgar and Wang-Li, Lingjuan}, year={2022}, month={Jan}, pages={328} }
 @article{akter_liu_cheng_classen_oviedo_harris_wang-li_2022, title={Impacts of Air Velocity Treatments under Summer Conditions: Part II—Heavy Broiler’s Behavioral Response}, volume={12}, ISSN={2076-2615}, url={http://dx.doi.org/10.3390/ani12091050}, DOI={10.3390/ani12091050}, abstractNote={Simple Summary Behavioral changes are one of the mechanisms for broilers to adjust their body temperature under heat stress conditions. However, the behavioral responses of heavy broilers to environmental changes have not yet been studied well. Therefore, this research investigated the behavioral changes of broilers under two dynamic air velocity treatments (high and low) under summer conditions. Video data collected from a heat stress experiment conducted on broilers aged 42–54 days were used to investigate variations in the number of chickens feeding, drinking, standing, walking, sitting, wing flapping, and leg stretching. The results indicated that the high air velocity treatments increased the number of chickens feeding, standing, and walking. In addition, age significantly affected the number of birds feeding, drinking, panting, and sitting, while the time of the day also affected the number of chickens drinking and panting. This study reveals the thermal stress of heavy broilers from their behavior under summer conditions to help manage the performance and welfare of birds under environmental stress. Abstract Broiler chickens exposed to heat stress adapt to various behavioral changes to regulate their comfortable body temperature, which is critical to ensure their performance and welfare. Hence, assessing various behavioral responses in birds when they are subjected to environmental changes can be essential for assessing their welfare under heat-stressed conditions. This study aimed to evaluate the effect of two air velocity (AV) treatments on heavy broilers’ behavioral changes from 43 to 54 days under summer conditions. Two AV treatments (high and low) were applied in six poultry growth chambers with three chambers per treatment and 44 COBB broilers per chamber from 28 to 61 days in the summer of 2019. Three video cameras placed inside each chamber (2.44 m × 2.44 m × 2.44 m in dimension) were used to record the behavior of different undisturbed birds, such as feeding, drinking, resting, standing, walking, panting, etc. The results indicate that the number of chickens feeding, drinking, standing, walking, sitting, wing flapping, and leg stretching changed under AV treatments. High AV increased the number of chickens feeding, standing, and walking. Moreover, a two-way interaction with age and the time of day can affect drinking and panting. This study provides insights into heavy broilers’ behavioral changes under heat-stressed conditions and AV treatments, which will help guide management practices to improve birds’ performance and welfare under commercial conditions in the future.}, number={9}, journal={Animals}, publisher={MDPI AG}, author={Akter, Suraiya and Liu, Yingying and Cheng, Bin and Classen, John and Oviedo, Edgar and Harris, Dan and Wang-Li, Lingjuan}, year={2022}, month={Apr}, pages={1050} }
 @article{cheng_wang-li_classen_bloomfield_2022, title={Performance of a Thermodynamic Model for Predicting Inorganic Aerosols in the Southeastern U.S.}, volume={13}, ISSN={2073-4433}, url={http://dx.doi.org/10.3390/atmos13121977}, DOI={10.3390/atmos13121977}, abstractNote={Fine particulate matter (i.e., PM2.5) has gained intensive attention due to its adverse health and visibility degradation effects. As a significant fraction of atmospheric PM2.5, secondary inorganic PM2.5 may be formed through the gas-phase ammonia (NH3) and particle-phase ammonium (NH4+) partitioning. While partitioning of NH3-NH4+ may be simulated using a thermodynamic equilibrium model, disagreement between model predictions and measurements have been realized. In addition, the applicability of the model under different conditions has not been well studied. This research aims to investigate the applicability of a thermodynamic equilibrium model, ISORROPIA II, under different atmospheric conditions and geographic locations. Based upon the field measurements at the Southeastern Aerosol Research and Characterization (SEARCH) network, the performance of ISORROPIA II was assessed under different temperature (T), relative humidity (RH), and model setups in urban and rural locations. The impact of organic aerosol (OA) on the partitioning of NH3-NH4+ was also evaluated. Results of this research indicate that the inclusion of non-volatile cations (NVCs) in the model input is necessary to improve the model performance. Under high T (>10 °C) and low RH (<60%) conditions, ISORROPIA II tends to overpredict nitric acid (HNO3) concentration and underpredict nitrate (NO3−) concentration. The predominance of one phase of semi-volatile compound leads to low accuracy in the model prediction of the other phase. The model with stable and metastable setups may also perform differently under different T-RH conditions. Metastable model setup might perform better under high T (>10 °C) and low RH (<60%) conditions, while stable model setup might perform better under low T (<5 °C) conditions. Both model setups have consistent performance when RH is greater than 83%. Future studies using ISORROPIA II for the prediction of NH3-NH4+ partitioning should consider the inclusion of NVCs, the under/over prediction of NO3−/HNO3, the selection of stable/metastable model setups under different T-RH conditions, and spatiotemporal variations of inorganic PM2.5 chemical compositions.}, number={12}, journal={Atmosphere}, publisher={MDPI AG}, author={Cheng, Bin and Wang-Li, Lingjuan and Classen, John and Bloomfield, Peter}, year={2022}, month={Nov}, pages={1977} }
 @article{wang_dai_wang_wang-li_yang_xiao_he_wang_2022, title={Size-segregated physicochemical properties of inhalable particulate matter in a tunnel-ventilated layer house in China}, volume={204}, ISSN={["1096-0953"]}, url={https://doi.org/10.1016/j.envres.2021.112064}, DOI={10.1016/j.envres.2021.112064}, abstractNote={This study investigated the physicochemical properties of the particles in a typical commercial laying hen barn in Southeast China. Mass concentrations and size distributions of the particulate matter (PM) and the key components (incl. organic carbon (OC), element carbon (EC), and the water-soluble inorganic ions (WSIIs)) were analyzed. The result shows that the mass concentrations of PM accumulated along with the airflow inside the house, with the total mass of the sampling particles increasing from 843.66 ± 160.74 μg/m3 at the center of the house to 1264.93 ± 285.70 μg/m3 at the place close to exhaust fans. The particles with the aerodynamic equivalent diameter, Dp > 9 μm, coarse particles (2.1 μm < Dp ≤ 9 μm), fine particles (Dp ≤ 2.1 μm) accounted for around 50%, 40%, and 10% of the total mass of the sampling particles, respectively. Mass closure analysis shows secondary inorganic ions (NH4+, SO42- and NO3-) were abundant in the fine-mode fraction and OC accounted for more than 40% of the coarse particles. Size distribution analysis shows that the three secondary inorganic ions were bimodally distributed, and the rest tested components were unimodally distributed. The ratios of OC/EC in fine particles were smaller than those in the coarse particles. The equivalent concentration of WSIIs indicated that fine particles were slightly acidic, and the large size particles were slightly alkaline. Knowledge gained from this study will lead to a better understanding of physicochemical properties, sources, and formation of PM.}, journal={ENVIRONMENTAL RESEARCH}, author={Wang, Xiaoshuai and Dai, Xiaorong and Wang, Ailun and Wang-Li, Lingjuan and Yang, Mengrong and Xiao, Hang and He, Yong and Wang, Kaiying}, year={2022}, month={Mar} }
 @article{hu_cheng_wang-li_2021, title={CHARACTERISTICS OF PARTICULATE MATTER EMISSIONS FROM SWINE AND POULTRY PRODUCTION HOUSES IN THE UNITED STATES}, volume={64}, ISSN={["2151-0040"]}, DOI={10.13031/trans.14622}, abstractNote={HighlightsParticulate matter (PM) data were analyzed to identify PM emission characteristics among different animal types.The PM concentrations were higher in broiler chicken and swine farrowing houses and were higher in winter.The PM emissions were also higher in broiler chicken houses and swine farrowing rooms.The PM in the layer chicken house in Indiana had narrower distributions with a greater percentage of smaller particles.Abstract. Understanding the characteristics of particulate matter (PM) emissions from animal feeding operations (AFOs) is essential to address the associated health and environmental impacts and to develop control strategies to mitigate such impacts. This article reports a study of PM concentrations and emission characteristics from 26 poultry and swine production houses to investigate the similarities and differences in PM emission characteristics, e.g., concentrations, emission rates, and particle size distribution (PSD), among different animal and housing types. Concentration and emission data for PM2.5, PM10, and total suspended particulates (TSP) collected by the National Air Emission Monitoring Study (NAEMS) were used to compare the differences among different production practices and animal types. The PSDs of the PM were examined based on the PM2.5/PM10 and PM10/TSP emission rate ratios. It was discovered that the concentrations of PM varied among animal types. For poultry, the concentrations of PM were higher in broiler houses than in other poultry houses. For swine, the average concentrations of PM were higher in farrowing rooms than in swine barns. Moreover, the PM concentrations in poultry and swine houses exhibited significant seasonal trends, with higher concentrations in winter and lower concentrations in summer, which were in a reverse relationship with ventilation rates. The PM emissions also varied among animal types. For poultry, the PM emissions were significantly higher for poultry production houses in California. For swine, the PM emissions were significantly higher for farrowing rooms than other swine houses. The PSD of PM varied among animal types, with mass median diameters (MMD) in the ranges of 6.51 to 13.62 µm for poultry houses and 7.94 to 17.19 µm for swine houses. The geometric standard deviations (GSD) were in the ranges of 1.66 to 2.71 and 1.65 to 2.9 for poultry and swine PM, respectively. The PM in the layer house in Indiana had a narrower distribution (smaller GSD) with a greater percentage of smaller particles than the other poultry houses, while the PM in the broiler house in California had a broader distribution (larger GSD) than the other poultry houses. For swine, the PM in the sow barn in North Carolina had a narrower distribution (smaller GSD) than the other swine houses, while the PM in the farrowing houses in Oklahoma had a broader distribution (larger GSD) than the other swine houses. The knowledge gained from this research may provide insights for addressing the PM emissions from various animal production systems. Keywords: Concentration and emission, Particulate matter, PM2.5, PM10, Poultry, swine, PSD, TSP.}, number={5}, journal={TRANSACTIONS OF THE ASABE}, author={Hu, Fei and Cheng, Bin and Wang-Li, Lingjuan}, year={2021}, pages={1569–1579} }
 @article{cheng_kumar_wang-li_2021, title={INVERSE AERMOD AND SCIPUFF DISPERSION MODELING FOR FARM-LEVEL PM10 EMISSION RATE ASSESSMENT}, volume={64}, ISSN={["2151-0040"]}, DOI={10.13031/trans.14311}, abstractNote={HighlightsAERMOD and SCIPUFF were employed to back-calculate farm-level PM10 emission rates based on inverse modeling.Both AERMOD and SCIPUFF did not capture the diurnal and seasonal variations of farm-level PM10 emission rates.AERMOD modeling results were affected by wind speed, with higher wind speed leading to higher emission rates.Higher numbers of receptors and PM10 measurements with greater time resolution may be recommended in the future.Abstract. Air pollutant emissions from animal feeding operations (AFOs) have become a serious concern for public health and ambient air quality. Particulate matter with aerodynamic equivalent diameter less than or equal to 10 µm (PM10) is one of the major air pollutants emitted from AFOs. To assess the impacts of PM10 emissions from AFOs, knowledge about farm-level PM10 emission rates is needed but is challenging to obtain through field measurements. The inverse dispersion modeling approach provides an alternative way to estimate farm-level PM10 emission rates. In this study, two dispersion models, AERMOD and SCIPUFF, were employed to back-calculate farm-level PM10 emission rates based on hourly PM10 concentration measurements at four downwind locations in the vicinity of a commercial egg production farm in the southeast U.S. Onsite meteorological data were simultaneously recorded using a 10 m weather tower to facilitate the dispersion modeling. The modeling results were compared with PM10 emission measurements from two layer houses on the farm. Single-area source, double-area source, and double-volume source were used in AERMOD, while only single-point source was used in SCIPUFF. The inverse modeling results indicated that both SCIPUFF and AERMOD did not capture the diurnal and seasonal variations of the farm-level PM10 emission rates. In addition, the AERMOD modeling results were affected by wind speed, and higher emission rates may be predicted at higher wind speeds. The single-point source for SCIPUFF, the plume rise simplification for AERMOD, and insufficient concentration measurement resolution in response to temporal changes in wind direction may have added uncertainties to the modeling results. The results of this study suggest that more receptors covering more representative downwind locations should be considered in future modeling for farm-level emissions assessment. Moreover, ambient data collection with greater time resolution (e.g., less than one hour) is recommended to capture diurnal and seasonal patterns more rigorously. Only in this way can researchers achieve a better understanding of the effectiveness of inverse dispersion modeling for estimation of pollutant emission rates. Keywords: AERMOD, Animal feeding operations, Egg production, Farm-level emission rate, Inverse dispersion modeling, PM10, SCIPUFF.}, number={3}, journal={TRANSACTIONS OF THE ASABE}, author={Cheng, B. and Kumar, A. P. Shiv and Wang-Li, L.}, year={2021}, pages={801–817} }
 @article{cheng_wang-li_meskhidze_classen_bloomfield_2021, title={Partitioning of NH3-NH4+ in the Southeastern U.S.}, volume={12}, ISSN={2073-4433}, url={http://dx.doi.org/10.3390/atmos12121681}, DOI={10.3390/atmos12121681}, abstractNote={The formation of inorganic fine particulate matter (i.e., iPM2.5) is controlled by the thermodynamic equilibrium partitioning of NH3-NH4+. To develop effective control strategies of PM2.5, we aim to understand the impacts of changes in different precursor gases on iPM2.5 concentrations and partitioning of NH3-NH4+. To understand partitioning of NH3-NH4+ in the southeastern U.S., responses of iPM2.5 to precursor gases in four seasons were investigated using field measurements of iPM2.5, precursor gases, and meteorological conditions. The ISORROPIA II model was used to examine the effects of changes in total ammonia (gas + aerosol), total sulfuric acid (aerosol), and total nitric acid (gas + aerosol) on iPM2.5 concentrations and partitioning of NH3-NH4+. The results indicate that reduction in total H2SO4 is more effective than reduction in total HNO3 and total NH3 to reduce iPM2.5 especially under NH3-rich condition. The reduction in total H2SO4 may change partitioning of NH3-NH4+ towards gas-phase and may also lead to an increase in NO3− under NH3-rich conditions, which does not necessarily lead to full neutralization of acidic gases (pH < 7). Thus, future reduction in iPM2.5 may necessitate the coordinated reduction in both H2SO4 and HNO3 in the southeastern U.S. It is also found that the response of iPM2.5 to the change in total H2SO4 is more sensitive in summer than winter due to the dominance of SO42− salts in iPM2.5 and the high temperature in summer. The NH3 emissions from Animal Feeding Operations (AFOs) at an agricultural rural site (YRK) had great impacts on partitioning of NH3-NH4+. The Multiple Linear Regression (MLR) model revealed a strong positive correlation between cation-NH4+ and anions-SO42− and NO3−. This research provides an insight into iPM2.5 formation mechanism for the advancement of PM2.5 control and regulation in the southeastern U.S.}, number={12}, journal={Atmosphere}, publisher={MDPI AG}, author={Cheng, Bin and Wang-Li, Lingjuan and Meskhidze, Nicholas and Classen, John and Bloomfield, Peter}, year={2021}, month={Dec}, pages={1681} }
 @article{cheng_wang-li_2019, title={Responses of secondary inorganic PM<inf>2.5</inf> to precursor gases in an Ammonia Abundant area in North Carolina}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85069175937&partnerID=MN8TOARS}, DOI={10.4209/aaqr.2018.10.0384}, abstractNote={Secondary inorganic fine particulate matter (iPM2.5) constitutes a significant amount of the atmospheric PM2.5. The formation of secondary iPM2.5 is characterized by thermodynamic equilibrium gas-particle partitioning of gaseous ammonia (NH3) and aerosol ammonium (NH4+). To develop effective strategies for controlling atmospheric PM2.5, it is essential to understand the responses of secondary iPM2.5 to different precursor gases. In southeastern North Carolina, the amount of NH3 is in excess to fully neutralize acidic gases (i.e., NH3-rich conditions). NH3-rich conditions are mainly attributed to the significant NH3 emissions in the region, especially from the large amounts of animal feeding operation (AFO). To gain a better understanding of the impact of NH3 on the formation of secondary iPM2.5 in this area, the responses of iPM2.5 to precursor gases under different ambient conditions were investigated based upon three-year monitoring data of the chemical components in iPM2.5, gaseous pollutants, and meteorological conditions. The gas ratio (GR) was used to assess the degree of neutralization via NH3, and ISORROPIA II model simulation was used to examine the responses of iPM2.5 to changes in the total NH3, the total sulfuric acid (H2SO4), and the total nitric acid (HNO3). It was discovered that under different ambient temperature and humidity conditions, the responses of iPM2.5 to precursor gases vary. In general, iPM2.5 responds nonlinearly to the total NH3 but linearly to the total H2SO4 and the total HNO3. In NH3-rich regions, iPM2.5 is not sensitive to changes in the total NH3, but it is very sensitive to changes in the total H2SO4 and/or the total HNO3. Reducing the total H2SO4, as opposed to the total HNO3 or the total NH3, leads to a significant reduction in iPM2.5 and is thus a more effective strategy for decreasing the concentration of iPM2.5. This research provides insight into controlling and regulating PM2.5 in NH3-rich regions.}, number={5}, journal={Aerosol and Air Quality Research}, author={Cheng, B. and Wang-Li, L.}, year={2019}, pages={1126–1138} }
 @article{cheng_wang-li_2019, title={Spatial and Temporal Variations of PM2.5 in North Carolina}, volume={19}, ISSN={["2071-1409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85065388819&partnerID=MN8TOARS}, DOI={10.4209/aaqr.2018.03.0111}, abstractNote={Studies have indicated that the adverse effects on human health and the decrease in visibility caused by fine particulate matter (PM2.5) exhibit spatial heterogeneity. Moreover, the environmental effects produced by different chemical compositions of PM2.5 vary on a regional scale. Therefore, understanding the spatiotemporal variations and chemical compositions of PM2.5 is necessary for assessing the regional impacts. Secondary inorganic PM2.5 (iPM2.5) is formed through chemical reactions between the base gas NH3 and acidic gas pollutants (e.g., NO2 or SO2). The major components of iPM2.5 include NH4+, SO42–, and NO3–. To fully comprehend the regional impacts of PM2.5, this research quantifies the spatiotemporal variations of iPM2.5 with the aim of evaluating the contributions from iPM2.5 to PM2.5 in North Carolina (NC). The concentrations (at 34 sites) and chemical components (at 7 sites) of PM2.5 from 2005 to 2014 were extracted from the EPA’s AirData, with the highest concentrations measured in the urban areas of central NC. Notably, PM2.5 concentrations have been significantly reduced over the past 10 years, with a concurrent decreasing trend in iPM2.5. Seasonal variation analysis indicates that PM2.5 concentrations were higher in summer and lower in winter; however, significant variation occurred only between 2005 and 2011. Although iPM2.5 formed the largest mass fraction of PM2.5 for 2005–2011, organic carbon matter (OCM) contributed the dominant share for 2012–2014. Significant seasonal variations in the iPM2.5 mass fractions were also observed, with NO3– and SO42– exhibiting inverse variations. This study links the ambient PM2.5 to various sources by revealing the spatiotemporal variations of PM2.5 and their associated chemical compositions in NC, thereby enabling the development of effective control and mitigation strategies.}, number={4}, journal={AEROSOL AND AIR QUALITY RESEARCH}, author={Cheng, Bin and Wang-Li, Lingjuan}, year={2019}, month={Apr}, pages={698–710} }
 @article{cheng_wang-li_meskhidze_classen_bloomfield_2019, title={Spatial and temporal variations of PM2.5 mass closure and inorganic PM2.5 in the Southeastern U.S.}, volume={26}, ISSN={0944-1344 1614-7499}, url={http://dx.doi.org/10.1007/s11356-019-06437-8}, DOI={10.1007/s11356-019-06437-8}, abstractNote={Fine particulate matter (i.e., PM 2.5 ) has gained extensive attention owing to its adverse effects. The impacts of PM 2.5  may vary in time and space due to the spatiotemporal variations of PM 2.5  number size distribution and chemical compositions. This research analyzed the latest PM 2.5  chemical compositions measurements with an aim to better understand the dynamic changes of PM 2.5  in response to emission reductions due to the new regulations. The particulate measurements from the Southeastern Aerosol Research and Characterization (SEARCH) network between 2001 and 2016 were analyzed for the spatiotemporal variations of PM 2.5  and inorganic PM 2.5  (iPM 2.5  = SO 4 2-  + NH 4 +  + NO 3 - ) chemical compositions in the Southeastern United States (U.S.). It was discovered that PM 2.5  and iPM 2.5  mass concentrations exhibited significant downward trends in 2001-2016. Both PM 2.5  and iPM 2.5  mass concentrations were higher at urban and inland sites than rural/suburban and coastal sites. The higher iPM 2.5  concentrations at agricultural sites were attributed to the influences of ammonia (NH 3 ) emissions from animal feeding operations (AFOs). The iPM 2.5  was the dominant contributor to PM 2.5  in 2001-2016 at the coastal sites, whereas organic carbon matter (OCM) was the major contributor to PM 2.5  after 2011 at the inland sites. Our data analysis suggests that significant decrease of PM 2.5  concentrations is attributed to the reductions in nitrogen oxides (NO x ) and sulfur dioxide (SO 2 ) emissions in 2001-2016. Findings from this research provide insights into the development of effective PM 2.5  control strategies and assessment of air pollutants exposure.}, number={32}, journal={Environmental Science and Pollution Research}, publisher={Springer Science and Business Media LLC}, author={Cheng, Bin and Wang-Li, Lingjuan and Meskhidze, Nicholas and Classen, John and Bloomfield, Peter}, year={2019}, month={Sep}, pages={33181–33191} }
 @article{ajami_shah_wang-li_kolar_castillo_2019, title={Windbreak Wall-Vegetative Strip System to Reduce Air Emissions from Mechanically Ventilated Livestock Barns: Part 2—Swine House Evaluation}, volume={230}, ISSN={0049-6979 1573-2932}, url={http://dx.doi.org/10.1007/s11270-019-4335-2}, DOI={10.1007/s11270-019-4335-2}, number={12}, journal={Water, Air, & Soil Pollution}, publisher={Springer Science and Business Media LLC}, author={Ajami, Ali and Shah, Sanjay B. and Wang-Li, Lingjuan and Kolar, Praveen and Castillo, Miguel S.}, year={2019}, month={Dec}, pages={289} }
 @article{ajami_shah_wang-li_kolar_castillo_2019, title={Windbreak Wall-Vegetative Strip System to Reduce Air Emissions from Mechanically Ventilated Livestock Barns—Part 3: Layer House Evaluation}, volume={230}, ISSN={0049-6979 1573-2932}, url={http://dx.doi.org/10.1007/s11270-019-4345-0}, DOI={10.1007/s11270-019-4345-0}, number={12}, journal={Water, Air, & Soil Pollution}, publisher={Springer Science and Business Media LLC}, author={Ajami, Ali and Shah, Sanjay B. and Wang-Li, Lingjuan and Kolar, Praveen and Castillo, Miguel S.}, year={2019}, month={Dec} }
 @article{measurements and visualization of the fluid field of the plume from an animal housing ventilation fan_2017, journal={Journal of Environmental Protection}, year={2017}, month={Aug} }
 @article{modeling plume-rise of air emissions from animal housing systems: inverse aermod_2017, volume={8}, number={11}, journal={Journal of Environmental Protection}, year={2017}, month={Aug}, pages={1254–1269} }
 @article{lin_shah_wang-li_oviedo-rondón_post_2016, title={Development of MOS sensor-based NH3 monitor for use in poultry houses}, volume={127}, ISSN={0168-1699}, url={http://dx.doi.org/10.1016/J.COMPAG.2016.07.033}, DOI={10.1016/j.compag.2016.07.033}, abstractNote={To ensure poultry performance and welfare, ammonia (NH3) concentrations inside poultry houses have to be within acceptable limits; this requires regular NH3 monitoring. While there are low-cost, portable NH3 measuring devices have drawbacks. Due to its low cost, long lifetime, and short response time, a metal oxide semiconductor (MOS) sensor was used to develop a handheld NH3 monitor for use in poultry houses. Since the MOS sensor is affected by humidity and temperature, collocating relative humidity (RH) and temperature sensors with the MOS NH3 sensor and applying temperature and RH compensations greatly improved its performance. Compared to the boric acid scrubber, using broiler litter exhaust gas as the NH3 source, the relative error (RE) and coefficient of variation (CV) of the monitor averaged 7%, comparable to research-grade instruments. The monitor was more accurate than the electrochemical sensor and required less frequent purging. The response time of the unit was ∼1.5 min, the total mass was <1.4 kg while material cost was <$430. Hence, in addition to being convenient, the monitor provided accurate and precise measurements. With further refinements, the monitor has the potential to be used in poultry houses to control ventilation rates as a component of precision livestock farming to improve poultry performance and welfare.}, journal={Computers and Electronics in Agriculture}, publisher={Elsevier BV}, author={Lin, Tianheng and Shah, Sanjay B. and Wang-Li, Lingjuan and Oviedo-Rondón, Edgar O. and Post, Justin}, year={2016}, month={Sep}, pages={708–715} }
 @article{padavagod shivkumar_wang-li_shah_stikeleather_fuentes_2016, title={Performance analysis of a poultry engineering chamber complex for animal environment, air quality, and welfare studies}, volume={59}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84998775201&partnerID=MN8TOARS}, DOI={10.13031/trans.59.11402}, abstractNote={<abstract> <b><sc>Abstract.</sc></b> Studies of animal welfare and air quality require good understanding of the production environment. This study evaluated the performance of a dedicated poultry engineering chamber complex (PECC) designed to conduct studies for enhancement in poultry production, air quality, and animal welfare. The performance evaluation of the PECC was carried out by direct flow testing and computational fluid dynamics (CFD) modeling. The flow rate measurements at six different blower speeds () in each of the six chambers and the corresponding pressure drops across the system indicated the effects of structural geometry and components on the flow characteristics. There was no significant difference in mean flow rate among chambers (p = 0.956). The flow in the animal-occupied zone (core chamber) was simulated using CFD, and the results were validated using field measurements. The average air velocities at bird height at blower speeds of 600 and 1200 obtained using direct measurements were 0.794 ±0.15 m s<sup>-1</sup> and 1.706 ±0.305 m s<sup>-1</sup>, respectively, and the average air velocities obtained using CFD models were 0.809 ±0.169 m s<sup>-1</sup> and 1.642 ±0.395 m s<sup>-1</sup>, respectively. Error analysis at each measurement point indicated a maximum value of 13.59% at bird height due to the presence of feeders. Statistical analysis showed no significant difference between measured and simulated results (p = 0.5415). The normalized mean square error was 0.007, indicating good agreement of simulated results with measurements. Certain regions in the animal-occupied zone had lower air velocity on average and therefore higher mean surface temperature of bird models in those regions, caused by the flocking effect.}, number={5}, journal={Transactions of the ASABE}, author={Padavagod Shivkumar, A. and Wang-Li, L. and Shah, S.B. and Stikeleather, L.F. and Fuentes, M.}, year={2016}, pages={1371–1382} }
 @article{hu_wang-li_simmons_classen_osborne_2016, title={Size Distributions of Bioaerosols in an Egg Production Facility and Its Vicinity}, volume={33}, ISSN={["1557-9018"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84964715430&partnerID=MN8TOARS}, DOI={10.1089/ees.2015.0220}, abstractNote={Abstract Air emissions from animal feeding operations may cause elevated concentrations of bioaerosols in surrounding areas, posing adverse health effects to the people working on or living near the farm. Concentrations of nonselective airborne bacteria and fungi in various size ranges were measured by the Andersen six-stage viable samplers in an egg production house and at four ambient stations surrounding the farm in winter, spring, and summer. It was discovered that in-house bacterial particle size distributions (PSDs) were different among seasons. Under higher temperature and lower relative humidity conditions, more bacteria were associated with the small size ranges. Seasonal variations of in-house fungal PSDs were not significant. On average, 60–80% of in-house bacteria were in respirable size range (≤4.7 μm), whereas 60–70% of in-house fungi were in respirable size range. Bacterial PSDs at ambient locations were different among stations in winter but not in spring and summer. There were significant...}, number={4}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Hu, Di and Wang-Li, Lingjuan and Simmons, Otto D. and Classen, John J. and Osborne, Jason A.}, year={2016}, month={Apr}, pages={215–223} }
 @article{wang_li_wang-li_cortus_bogan_kilic_liang_xiao_chai_ni_et al._2016, title={The National Air Emissions Monitoring study's southeast layer site: Part V. Hydrogen sulfide and volatile organic compounds}, volume={59}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84964758698&partnerID=MN8TOARS}, DOI={10.13031/trans.59.11150}, abstractNote={Aerial pollutants generated from intensive poultry and livestock production raise concerns of health and welfare for the surrounding communities. This article reports emission rates of hydrogen sulfide (H 2 S) and concentrations of volatile organic compounds (VOCs) from two tunnel-ventilated high-rise houses at a layer site in North Carolina that were tested by the National Air Emissions Monitoring Study (NAEMS). Hydrogen sulfide concentrations exhibited significant seasonal and diurnal variations. The minimum and maximum average hourly mean (AHM) concentrations by hour of day occurred at 15:00-16:00 and 6:00-7:00, respectively. The lowest and highest daily mean concentrations during the annual cycle were observed in summer and winter, respectively. The AHM H 2 S concentrations were 1.04 ±0.83 ppb for inlet air and 9.52 ±6.35 and 9.43 ±6.01 ppb, respectively, for exhaust air from the two production houses. The diurnal and seasonal patterns of H 2 S emission rates from the two production houses were also similar. Slight increases in H 2 S emission rates occurred at 12:00 to 14:00. Higher H 2 S emission rates occurred in summer. The AHM hen-specific H 2 S emission rates from the two production houses were 618 ±517 and 698 ±620 I¼g d -1 hen -1 , respectively. Factors significantly affecting H 2 S emissions were hen activity, house exhaust air temperature, and ambient air temperature. Time-integrated samples of VOCs were collected over 24 h periods seven times in one production house from 12 April 2009 to 18 September 2009. Of 77 target compounds, the ten most abundant compounds were 2-butanone, iso-propanol, dimethyl sulfide, hexanal, acetic acid, 2,3-butanedione, pentane, acetaldehyde, pentanal, and phenol. Differences in VOC concentrations were observed between the layer room and the manure pit. The highest total VOC concentration was detected in samples taken from the manure pit exhaust air.}, number={2}, journal={Transactions of the ASABE}, author={Wang, K.-Y. and Li, Q.-F. and Wang-Li, L. and Cortus, E.L. and Bogan, B.W. and Kilic, I. and Liang, W.-Z. and Xiao, C.-H. and Chai, L.-L. and Ni, J.-Q. and et al.}, year={2016}, pages={681–693} }
 @article{hood_shah_kolar_li_stikeleather_2015, title={Biofiltration of Ammonia and GHGs from Swine Gestation Barn Pit Exhaust}, volume={58}, ISSN={2151-0032 2151-0040}, url={http://dx.doi.org/10.13031/trans.58.10949}, DOI={10.13031/trans.58.10949}, abstractNote={<abstract> <b><sc>Abstract.</sc></b> Livestock barn emissions can affect public health, the environment, and quality of life. While these emissions can be mitigated using several methods, exhaust air treatment may be required in some situations. Biofiltration is one of the most cost-effective exhaust air treatment methods. In a biofilter, polluted air passes through a moist medium (e.g., compost) where the water-soluble gases are dissolved and then degraded by microorganisms into harmless or less harmful compounds. In this study, a downflow biofilter using a compost and wood chip medium was evaluated over summer, fall, and winter (August 2010 to January 2011) for its ability to mitigate emissions of ammonia (NH<sub>3</sub>) and three greenhouse gases (GHGs): methane (CH<sub>4</sub>), nitrous dioxide (N<sub>2</sub>O), and carbon dioxide (CO<sub>2</sub>). Biofilter medium properties were analyzed at the beginning and twice during the study. Changes in medium properties and CO<sub>2</sub> data indicated greater heterotrophic microbial activity during summer through fall and greater autotrophic activity during fall through winter. Regardless of empty bed residence time (EBRT) (5.3 to 26 s), NH<sub>3</sub> removal efficiency (RE) was about 90% with inlet concentrations of ≤1.1 mg m<sup>-3</sup>. With higher NH<sub>3</sub> loading rates, the RE may differ from this study. In fall, CH<sub>4</sub> RE was 49% (EBRT = 26 s) but only 13% in summer (EBRT = 13 s). Nitrous oxide RE varied in a narrow range of 14% to 18% over the study. In summer, CO<sub>2</sub> removal was negligible but was 15% in fall and 34% in winter. While a compost based medium may be more effective for CH<sub>4</sub> and N<sub>2</sub>O mitigation, a wood chip based medium would be more economical. Care should be taken when using a photoacoustic sensor for high-frequency and low-concentration NH<sub>3</sub> measurements.}, number={3}, journal={Transactions of the ASABE}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Hood, Matthew C. and Shah, Sanjay B. and Kolar, Praveen and Li, Lingjuan Wang and Stikeleather, Larry}, year={2015}, month={Jun}, pages={771–782} }
 @article{elemental composition and chemical mass closure of fine particulate in an animal feeding operation facility and its vicinity_2015, journal={Journal of Environmental Protection}, year={2015}, month={Jun} }
 @article{wang-li_2015, title={Insights to the formation of secondary inorganic PM<inf>2.5</inf>: Current knowledge and future needs}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84928784561&partnerID=MN8TOARS}, DOI={10.3965/j.ijabe.20150802.1810}, number={2}, journal={International Journal of Agricultural and Biological Engineering}, author={Wang-Li, L.}, year={2015}, pages={1–13} }
 @article{spatiotemporal variations of bioaerosols in the vicinity of an animal feeding operation facility in the u.s_2015, journal={Journal of Environmental Protection}, year={2015}, month={Jun} }
 @article{li_wang-li_shah_jayanty_bloomfield_2014, title={Ammonia concentrations and modeling of inorganic particulate matter in the vicinity of an egg production facility in Southeastern USA}, volume={21}, ISSN={["1614-7499"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84895876258&partnerID=MN8TOARS}, DOI={10.1007/s11356-013-2417-z}, abstractNote={Ammonia (NH3) is an important base gas and can react with acidic species to form atmospheric aerosols. Due to the rapid growth of poultry and swine production in the North Carolina Coastal Plain, atmospheric NH3 concentrations across the region have subsequently increased. Ammonia concentrations and inorganic particulate matter (PM) at four ambient stations in the vicinity of an egg production facility were measured for 1 year using PM2.5 speciation samplers with honeycomb denuders and ion chromatography (IC). Meanwhile, concentrations of NH3 and inorganic PM in one of the egg production houses were also simultaneously measured using a gas analyzer for NH3 and the filter pack plus IC method for inorganic PM. An equilibrium model-ISORROPIA II was applied to predict the behavior of inorganic aerosols in response to precursor gas concentrations and environmental parameters. Average ambient NH3 concentrations varied from 10.0 to 27.0 μg/m(3), and they were negatively correlated with the distances from the ambient location to the nearest egg production house exhausts. Ambient NH3 concentrations were higher in warm seasons than in cold seasons. Measured NH3 concentrations agreed well with ISORROPIA II model predictions at all sampling stations. For the ambient stations, there was a good agreement in particle phase NH4 (+) between the model simulation and observations. For the in-house station, the model simulation was applied to correct the overestimation of particle phase NH4 (+) due to gas phase NH3 breaking through the denuders. Changes in SO4 (2-), NO3 (-), and Cl(-) yield proportional changes in inorganic PM mass. Due to the abundance of NH3 gas in the vicinity area of the monitored farm, changes in NH3 concentrations had a small effect on inorganic PM mass. Aerosol equilibrium modeling may be used to assess the influence of precursor gas concentrations on inorganic PM formation when the measurements for some species are unavailable.}, number={6}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Li, Qian-Feng and Wang-Li, Lingjuan and Shah, Sanjay B. and Jayanty, R. K. M. and Bloomfield, Peter}, year={2014}, month={Mar}, pages={4675–4685} }
 @article{hu_wang-li_simmons_classen_osborne_byfield_2014, title={Bioaerosol concentrations and emissions from tunnel-ventilated high-rise layer houses in north carolina}, volume={57}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84924343014&partnerID=MN8TOARS}, DOI={10.13031/trans.57.10489}, abstractNote={Abstract. In this study, concentrations of bacteria and fungi were measured in two high-rise, tunnel-ventilated egg production houses in North Carolina during winter, spring, and summer using Andersen six-stage samplers. Average concentrations of culturable airborne bacteria and fungi ranged from 2.2 A— 10 5 colony forming units (CFU) m -3 to 1.1 A— 10 6 CFU m -3 and from 1.5 A— 10 3 to 2.8 A— 10 3 CFU m -3 , respectively. In-house bacterial concentrations significantly differed over the three seasons but did not vary by time of day. In-house fungal concentrations were not significantly different over seasons or at different times of day. Among all influencing factors, indoor air temperature (T), relative humidity (RH), and house ventilation rate (Q) had significant impacts on in-house bioaerosol concentrations. Bacterial concentrations were significantly higher on the second floor of the high-rise layer house, while fungal concentrations were not significantly different on the two floors. Emission rates of both bacteria and fungi were highest in summer, possibly due to the elevated ventilation rates during the summer season. The findings of this study advance our knowledge about bioaerosol concentrations and emissions as impacted by various factors in egg production facilities.}, number={3}, journal={Transactions of the ASABE}, author={Hu, D. and Wang-Li, L. and Simmons, O.D. and Classen, J.J. and Osborne, J.A. and Byfield, G.E.}, year={2014}, pages={915–925} }
 @article{li_wang-li_liu_jayanty_shah_bloomfield_2014, title={Major ionic compositions of fine particulate matter in an animal feeding operation facility and its vicinity}, volume={64}, ISSN={1096-2247 2162-2906}, url={http://dx.doi.org/10.1080/10962247.2014.942442}, DOI={10.1080/10962247.2014.942442}, abstractNote={Animal feeding operations (AFOs) produce particulate matter (PM) and gaseous pollutants. Investigation of the chemical composition of PM2.5 inside and in the local vicinity of AFOs can help to understand the impact of the AFO emissions on ambient secondary PM formation. This study was conducted on a commercial egg production farm in North Carolina. Samples of PM2.5 were collected from five stations, with one located in an egg production house and the other four located in the vicinity of the farm along four wind directions. The major ions of NH4+, Na+, K+, SO42−, Cl−, and NO3− were analyzed using ion chromatography (IC). In the house, the mostly abundant ions were SO42−, Cl−, and K+. At ambient stations, SO42−, and NH4+ were the two most abundant ions. In the house, NH4+, SO42−, and NO3− accounted for only 10% of the PM2.5 mass; at ambient locations, NH4+, SO42−, and NO3− accounted for 36–41% of the PM2.5 mass. In the house, NH4+ had small seasonal variations indicating that gas-phase NH3 was not the only major force driving its gas–particle partitioning. At the ambient stations, NH4+ had the highest concentrations in summer. In the house, K+, Na+, and Cl− were highly correlated with each other. In ambient locations, SO42− and NH4+ had a strong correlation, whereas in the house, SO42− and NH4+ had a very weak correlation. Ambient temperature and solar radiation were positively correlated with NH4+ and SO42−. This study suggests that secondary PM formation inside the animal house was not an important source of PM2.5. In the vicinity, NH3 emissions had greater impact on PM2.5 formation. Implications The chemical composition of PM2.5 inside and in the local vicinity of AFOs showed the impact of the AFO emissions on ambient secondary PM2.5 formation, and the fate and transport of air pollutants associated with AFOs. The results may help to manage in-house animal facility air quality, and to develop regional air quality control strategies and policies, especially in animal agriculture-concentrated areas.}, number={11}, journal={Journal of the Air & Waste Management Association}, publisher={Informa UK Limited}, author={Li, Qian-Feng and Wang-Li, Lingjuan and Liu, Zifei and Jayanty, R.K.M. and Shah, Sanjay B. and Bloomfield, Peter}, year={2014}, month={Oct}, pages={1279–1287} }
 @article{wang-li_cao_li_liu_beasley_2013, title={Concentration and particle size distribution of particulate matter inside tunnel-ventilated high-rise layer operation houses}, volume={66}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84871094175&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2012.03.064}, abstractNote={Particulate matter (PM) is a criteria pollutant emitted from animal feeding operation (AFO) facilities, especially from poultry operation buildings. Fundamental data regarding AFO PM either do not exist, or are not representative of different animal production systems or housing types. This field study investigated particle size distributions (PSDs) and concentrations of total suspended particulate (TSP) in a tunnel ventilated high-rise layer house under different operational conditions. Six low-volume (1 m3 h−1) TSP samplers were used to collect PM samples on two floors of the high-rise layer houses across four seasons through day/night sampling protocols. The day/night sampling design was to examine animal activity impact. The PM samples were analyzed by a multi-wave length laser diffraction particle size analyzer (LS13 320) for PSDs characterized by mass median diameters (MMDs) and geometric standard deviations (GSDs). It was discovered that the mean TSP concentrations ranged from 1.0 ± 0.5 mg m−3 to 5.33 ± 0.36 mg m−3 (mean ± SD). TSP concentrations in winter were higher than in summer; concentrations on the 2nd floor were higher than that on the 1st floor; concentrations of daytime samples were higher than those of nighttime samples. Animal activity (represented by day/night samples) had the highest impact on TSP concentration as compared to other influential factors (spatial, seasonal, ventilation). No significant seasonal variations of MMD and GSD were observed in most of samples. Majority of day/night MMDs and GSDs demonstrated no significant differences. Thus the impact of animal activity (day vs. night) on MMD and GSD were not significant. Mean MMDs ± SDs ranged from 16.81 ± 1.57 μm to 20.26 ± 3.53 μm, whereas means ± SDs of GSDs ranged from 2.38 ± 0.20 to 2.81 ± 0.30. Mean PM2.5 fractions ± SDs ranged from 5.03 ± 1.60% to 8.93 ± 0.97%, whereas mean PM10 fractions ± SDs ranged from 23.25 ± 5.18% to 38.55 ± 2.96%. Significant seasonal variation in both PM10 and PM2.5 mass fractions were observed.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Wang-Li, Lingjuan and Cao, Zihan and Li, Qianfeng and Liu, Zifei and Beasley, David B.}, year={2013}, month={Feb}, pages={8–16} }
 @article{wang-li_li_byfield_2013, title={Identification of Bioaerosols Released from an Egg Production Facility in the Southeast United States}, volume={30}, ISSN={["1557-9018"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874096303&partnerID=MN8TOARS}, DOI={10.1089/ees.2011.0517}, abstractNote={This field study investigated biological characteristics of aerosols emitted from a commercial egg production farm (layer operation). Bioaerosol samples were taken on this farm at five sampling locations covering emission source (inside a layer barn) and four ambient surrounding stations at four wind directions. All-glass impingers (AGI) were used for the field sampling. AGI fluid samples were plated in duplicate on Trypticase Soy Agar for growth of bacteria and Sabouraud Dextrose Agar for growth of fungi. The most prominent bacterial colony types were identified using a combination of methods that include recording characteristics of colony morphology; performing a Gram staining method and metabolic analyses using the Biolog system. Results from thirty-five AGI samples taken at the five stations through seven sampling events over four seasons indicate that there were significantly lower total bacterial concentrations in the samples collected from ambient stations as compared with the samples collected in the layer house; the mean bacterial concentration at the in-house sampling station was 3.86×10(5)±1.74×10(5) cfu/m(3), whereas the mean bacterial concentrations at four ambient stations in the vicinity of the farm ranged from 1.3×10(3) to 6.2×10(3) cfu/m(3) with no significant differences in mean among ambient stations. There were also no significant differences in fungi concentrations among all sampling stations. Mean fungi concentrations at the in-house station was 3.0×10(3)±4.45×10(3) cfu/m(3), whereas the mean concentrations at the ambient stations ranged from 7.4×10(3) to 1.7×10(4) cfu/m(3). The most prominent bacterial species differed among all five stations. Three of the most prominent bacteria from samples taken at all five stations were gram positive. Fungal type also differed from station to station.}, number={1}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Wang-Li, Lingjuan and Li, Qianfeng and Byfield, Grace E.}, year={2013}, month={Jan}, pages={2–10} }
 @article{organic and elemental carbons in atmospheric fine particulate in an animal agriculture intensive area in north carolina: estimation of secondary organic carbon concentration_2013, journal={Open Journal of Air Pollution}, year={2013}, month={Feb} }
 @book{wang-li_2013, title={Techniques for characterization of particulate matter emitted from animal feeding operations}, volume={1126}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905409194&partnerID=MN8TOARS}, DOI={10.1021/bk-2013-1126.ch002}, abstractNote={In agricultural air quality studies, characterization of particulate matter (PM) emitted from animal feeding operations (AFOs) are of growing interest. Due to a lack of reference methods for AFO PM studies, significant variations in PM measurements exist among studies. Moreover, due to inherent limitations, different PM measurement techniques may give different results when used to sample PM in the same environment. A given technique may also demonstrate different magnitudes of sampling errors when exposed to different environmental conditions (e.g., humidity, etc.) or to PM with different characteristics (e.g. particle size, volatility, etc.). This chapter examines the scientific principles of various PM measurement techniques such that strengths and limitations of the techniques are revealed. Knowledge about causative factors associated with the limitations will lead to the appropriate selection of specific techniques to achieve the research goals for different sampling scenarios.}, journal={ACS Symposium Series}, author={Wang-Li, L.}, year={2013}, pages={15–39} }
 @article{wang-li_cao_buser_whitelock_parnell_zhang_2013, title={Techniques for measuring particle size distribution of particulate matter emitted from animal feeding operations}, volume={66}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84871086020&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2012.08.051}, abstractNote={While various techniques for measuring particle size distributions (PSD) of particulate matter (PM) exist, there is no a single agreed upon standard or reference method for PM with different characteristics. This study investigated differences in the PSD measurements by four PSD analyzers: LS13 320 multi-wave length laser diffraction particle size analyzer, LS230 laser diffraction particle size analyzer, LA-300 laser scattering particle size analyzer, and Coulter Counter Multisizer3 (CCM3). Simultaneously collected total suspended particulate (TSP) samples in a commercial egg production house were analyzed by the four analyzers for PSDs. In addition, four types of testing powders (limestone, starch, No.3 micro aluminum, and No.5 micro aluminum) were also analyzed by these four PSD analyzers. The results suggest when comparing measured mass median diameters (MMDs) and geometric standard deviations (GSD) of the PSDs, the laser diffraction method (LS13 320, LS230 and LA-300) provided larger MMDs and broader distributions (GSDs) than the electrical sensing zone method (CCM3) for all samples. When comparing mass fractions of PM10 and PM2.5 between the measured values and the lognormal fitting values derived from the measured MMDs and GSDs, lognormal fitting method produced reasonably accurate PM10 mass fraction estimations (within 5%), but it failed to produce accurate PM2.5 mass fraction estimations. The measured PM2.5 mass fractions significantly differed from the lognormal fitting PM2.5 fractions and the mean differences reached as high as 95%. It is strongly recommended that when reporting a PSD of certain PM samples, in addition to MMD and GSD, the mass fractions of PM10 and PM2.5 should also be reported.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Wang-Li, Lingjuan and Cao, Zihan and Buser, Michael and Whitelock, Derek and Parnell, Calvin B. and Zhang, Yuanhui}, year={2013}, month={Feb}, pages={25–32} }
 @article{wang-li_li_wang_bogan_ni_cortus_heber_2013, title={The national air emissions monitoring study's Southeast Layer Site: Part I. Site characteristics and monitoring methodology}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84884184545&partnerID=MN8TOARS}, DOI={10.13031/trans.56.9570}, abstractNote={Abstract. Air emissions from animal feeding operation (AFO) facilities have been of increasing concern. While the EPA was pressured to put more stringent regulations on the AFO industry, there was an absence of suitable emission data to support regulatory decisions for different AFOs due to limitations of past studies and the absence of standard measurement protocols that link an emission rate to the different activities responsible for the emissions. In 2005, the EPA announced the AFO Air Quality Compliance Agreement, under which a two-year National Air Emissions Monitoring Study (NAEMS) was initiated. The NAEMS Southeast Layer Site was designed to collect baseline air emissions from high-rise tunnel-ventilated layer houses. The target emissions at this site were ammonia (NH 3 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), volatile organic compounds (VOCs), and particulate matter (PM), including PM 2.5 , PM 10 , and total suspended particulate (TSP). In addition, operational and environmental variables (e.g., animal activity, room temperature and relative humidity (RH), house ventilation rate, ambient temperature and RH, wind speed and direction, and solar radiation) were monitored to address their impacts on the emissions. Information about house inventory and major farm management activities was also collected. This article documents site characteristics and monitoring methods for the NAEMS at the Southeast Layer Site. Baseline emissions of PM and gaseous pollutants, house ventilation rates, and apparent impacts of farm management activities are reported in parts II through VI of this series.}, number={3}, journal={Transactions of the ASABE}, author={Wang-Li, L. and Li, Q.-F. and Wang, K. and Bogan, B.W. and Ni, J.-Q. and Cortus, E.L. and Heber, A.J.}, year={2013}, pages={1157–1161} }
 @article{li_wang-li_wang_chai_cortus_kilic_bogan_ni_heber_2013, title={The national air emissions monitoring study's Southeast Layer Site: Part II. Particulate matter}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84884188730&partnerID=MN8TOARS}, DOI={10.13031/trans.56.9571}, abstractNote={Abstract. The National Air Emissions Monitoring Study (NAEMS) was established by the U.S. EPA and the U.S. livestock and poultry industries to address the lack of scientific air emission data needed for properly assessing compliance with federal air laws and regulations. A North Carolina egg layer farm (NC2B) was one of 20 NAEMS monitored farms. Emission rates of particulate matter (PM 2.5 , PM 10 , and TSP) from two high-rise layer houses at NC2B were determined based on continuous measurements of PM concentrations and house ventilation rates over a two-year period. The overall average PM 2.5 emission rate of both houses combined was 0.37 ±3.06 mg d -1 hen -1 with no significant difference between houses. The average PM 10 emission rates were 16.2 ±13.7 and 19.3 ±15.9 mg d -1 hen -1 from houses 3 and 4, respectively, and 17.8 ±14.9 mg d -1 hen -1 for both houses combined. The average TSP emission rates were 39.1 ±32.8 and 47.1 ±37.6 mg d -1 hen -1 for houses 3 and 4, respectively, and 43.1 ±35.5 mg d -1 hen -1 for both houses combined. The median hourly mean emission rates were 0.61, 14.7, and 31.7 mg d -1 hen -1 from house 3 and 0.72, 17.1, and 42.4 mg d -1 hen -1 from house 4 for PM 2.5 , PM 10 , and TSP, respectively. Significant temporal variations in PM concentrations and emissions were observed. Significant differences in PM concentrations were also observed between the manure pit and layer room. The PM emissions exhibited significant correlations with hen activity and house exhaust air temperature. An empirical PM emissions model was developed based on multiple regression analysis to predict PM emissions from this monitoring site.}, number={3}, journal={Transactions of the ASABE}, author={Li, Q.-F. and Wang-Li, L. and Wang, K. and Chai, L. and Cortus, E.L. and Kilic, I. and Bogan, B.W. and Ni, J.-Q. and Heber, A.J.}, year={2013}, pages={1173–1184} }
 @article{wang-li_li_chai_cortus_wang_kilic_bogan_ni_heber_2013, title={The national air emissions monitoring study's Southeast Layer Site: Part III. Ammonia concentrations and emissions}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84884174071&partnerID=MN8TOARS}, DOI={10.13031/trans.56.9673}, abstractNote={Abstract. This article reports two years of quality-assured measurements of concentrations and baseline emissions of ammonia (NH 3 ) at two tunnel-ventilated high-rise houses (houses 3 and 4) located at an egg production facility in North Carolina. The study was conducted as part of the National Air Emissions Monitoring Study (NAEMS). The inside NH 3 concentrations, as represented by the exhaust air, were characterized by significant diurnal and seasonal variations. The lowest exhaust concentrations (17.0 ±14.0 ppm in house 3; 15.8 ±13.0 ppm in house 4) were observed in early afternoon (i.e., 2:00 p.m. to 3:00 p.m.) at the maximum diurnal ventilation rate. The highest concentrations (29.5 ±22.7 ppm in house 3; 28.8 ±22.2 ppm in house 4) occurred in early morning (i.e., 2:00 a.m. to 3:00 a.m.) when the ventilation rate was the lowest. Similarly, the concentrations were lowest during summer and maximum ventilation rates, and highest during winter and minimum ventilation rates. The average NH 3 concentrations were 0.7, 22.9, and 20.7 ppm for inlet air and the exhausts of houses 3 and 4, respectively. The average daily mean NH 3 emission rate of house 3 (fully occupied and active) was 0.599 ±0.200 g d -1 hen -1 (197 ±66.3 g d -1 AU -1 , 18.2 ±6.04 g d -1 m -2 ) at an average ambient temperature of 16.7°C and that of house 4 was 0.600 ±0.250 g d -1 hen -1 (197 ±82.3 g d -1 AU -1 , 18.2 ±7.53 g d -1 m -2 ) at an average ambient temperature of 16.3°C. Ammonia emission rates exhibited less daily and seasonal variation than inside NH 3 concentrations. Slightly elevated NH 3 emission rates were observed in early afternoon (12:00 noon to 2:00 p.m.), when house temperatures were relatively high. No significant differences in emissions between summer and winter were observed. Factors significantly affecting hen-specific NH 3 emissions included house ventilation rate, ambient and exhaust air temperatures, exhaust air humidity ratio, hen population, hen activity, feed and water consumption rates, and manure accumulation time. Among all these factors, house exhaust temperature had the greatest effect on NH 3 emission rate, followed by manure accumulation time.}, number={3}, journal={Transactions of the ASABE}, author={Wang-Li, L. and Li, Q.-F. and Chai, L. and Cortus, E.L. and Wang, K. and Kilic, I. and Bogan, B.W. and Ni, J.-Q. and Heber, A.J.}, year={2013}, pages={1185–1197} }
 @article{li_wang-li_bogan_wang_chai_ni_heber_2013, title={The national air emissions monitoring study's southeast layer site: Part iv. Effects of farm management}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84884185668&partnerID=MN8TOARS}, DOI={10.13031/trans.56.9674}, abstractNote={Abstract. The effects of house lighting, forced molting, manure removal, and flock replacement on air pollutant concentrations and emissions from high-rise tunnel-ventilated layer houses were evaluated. Air pollutants included ammonia (NH 3 ), carbon dioxide (CO 2 ), and particulate matter (PM, including PM 10 , PM 2.5 , and total suspended particulate, TSP). Emission rates were determined based on ventilation rates and pollutant concentrations, which were monitored for two years. House lighting schedules, molting, manure removal, and flock replacement activities were documented by the producer. Hen activity was monitored continuously using commercial motion detectors and was observed to be much higher during light periods as compared with dark periods. The TSP and PM 10 emissions during light periods were about five times greater than during dark periods, whereas NH 3 and CO 2 emissions during light periods were about 20% higher. The NH 3 and CO 2 concentrations and emission rates decreased during molting and then increased afterward. Ammonia emission was directly proportional to hen body weight and feed consumption. Compared with NH 3 , CO 2 concentrations and emissions showed more variations during molting. During manure pit cleanouts, NH 3 and CO 2 emissions decreased from 0.62 to 0.21 g d -1 hen -1 and from 78 to 64 g d -1 hen -1 , respectively. After the manure pits were emptied, NH 3 and CO 2 emissions increased steadily during the first 3 to 7 d of manure accumulation and then remained relatively constant. Manure pit cleanout activities caused high PM emission. Particulate matter emission decreased gradually after the pits were cleaned. No significant changes in egg production, mortality, water consumption, or feed consumption were observed during manure removals. When compared with occupied houses, empty house emission rates of PM 10 , TSP, and NH 3 each decreased by more than 90%, and CO 2 decreased by more than 70%.}, number={3}, journal={Transactions of the ASABE}, author={Li, Q.-F. and Wang-Li, L. and Bogan, B.W. and Wang, K. and Chai, L. and Ni, J.-Q. and Heber, A.J.}, year={2013}, pages={1199–1209} }
 @article{li_wang-li_liu_heber_2012, title={Field evaluation of particulate matter measurements using tapered element oscillating microbalance in a layer house}, volume={62}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84860252608&partnerID=MN8TOARS}, DOI={10.1080/10473289.2011.650316}, abstractNote={The tapered element oscillating microbalance (TEOM) is one type of continuous ambient particulate matter (PM) monitor. Adsorption and desorption of moisture and semivolatile species may cause positive or negative artifacts in TEOM PM mass measurement. The objective of this field study was to investigate possible uncertainties associated with TEOM measurements in the poultry operation environment. For comparisons of TEOM with filter-based gravimetric method, four instruments (TEOM-PM10, low-volume PM10 sampler, TEOM-PM2.5, and PM2.5 speciation sampler) were collocated and tested inside a poultry house for PM2.5 and PM10 (PM with aerodynamic equivalent diameter ≤2.5 and ≤10 μm, respectively) measurements. Fifteen sets of 24-hr PM10 concentrations and 13 sets of 24-hr PM2.5 measurements were obtained. Results indicate that compared with filter-based gravimetric method, TEOM gave significantly lower values of both PM10 and PM2.5 mass concentrations. For PM10, the average ratio of TEOM to the gravimetric method was 0.936. For PM2.5, the average ratio of TEOM to the gravimetric method was 0.738. Particulate matter in the poultry houses possibly contains semivolatile compounds and moisture due to high levels of relative humidity (RH) and gas pollutants. The internal heating mechanism of the TEOM may cause losses in mass through volatilization. To investigate the effects of TEOM settings on concentration measurements, the heaters of two identical TEOMs were set at 50 °C, 30 °C, or no heating at all. They were collocated and tested for total suspended particle (TSP), PM10, and PM2.5 measurements in layer house for 6 weeks. For all TSP, PM10, and PM2.5 measurements, the internal TEOM temperature setting had a significant effect (P < 0.05). Significantly higher PM mass concentrations were measured at lower temperature settings. The effects of environmental (i.e., temperature, RH, NH3 and CO2 concentrations) and instrumental (i.e., filter loading and noise) parameters on PM measurements were also assessed using regression analysis. Implications Because of its potential health and environmental effects, particulate matter (PM) emissions from animal feeding operations (AFOs) have been a great concern to the public and to the regulatory agencies. The tapered element oscillating microbalance (TEOM) PM monitor has been was adapted for continuous PM measurements in some AFO air quality studies. This study investigated possible uncertainties associated with TEOM measurements in an egg production environment. It was discovered that there was a significant bias in TEOM measurements of PM10 as compared with federal reference method. Internal temperature settings of a TEOM have significant impact on its PM measurement.}, number={3}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Li, Qian-Feng and Wang-Li, Lingjuan and Liu, Zifei and Heber, Albert J.}, year={2012}, month={Mar}, pages={322–335} }
 @article{jones_wang-li_boroujeni_2012, title={Impact of downwind sampling location and height on inverse-Gaussian dispersion modeling: A theoretical study}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84871271494&partnerID=MN8TOARS}, DOI={10.3965/j.ijabe.20120504.00}, number={4}, journal={International Journal of Agricultural and Biological Engineering}, author={Jones, H.W. and Wang-Li, L. and Boroujeni, B.Y.}, year={2012} }
 @article{li_wang-li_walker_shah_bloomfield_jayanty_2012, title={Particulate matter in the vicinity of an egg production facility: Concentrations, statistical distributions, and upwind and downwind comparison}, volume={55}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84872306478&partnerID=MN8TOARS}, number={5}, journal={Transactions of the ASABE}, author={Li, Q.-F. and Wang-Li, L. and Walker, J.T. and Shah, S.B. and Bloomfield, P. and Jayanty, R.K.M.}, year={2012}, pages={1965–1973} }
 @article{yao_shah_willits_westerman_wang li_marshall_2011, title={Ammonia emissions from broiler cake stockpiled in a naturally ventilated shed}, volume={54}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-81755163497&partnerID=MN8TOARS}, number={5}, journal={Transactions of the ASABE}, author={Yao, H. and Shah, S.B. and Willits, D.H. and Westerman, P.W. and Wang Li, L. and Marshall, T.K.}, year={2011}, pages={1893–1904} }
 @article{li_wang-li_shah_jayanty_bloomfield_2011, title={Fine particulate matter in a high-rise layer house and its vicinity}, volume={54}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84862921384&partnerID=MN8TOARS}, number={6}, journal={Transactions of the ASABE}, author={Li, Q. and Wang-Li, L. and Shah, S.B. and Jayanty, R.K.M. and Bloomfield, P.}, year={2011}, pages={2299–2310} }
 @article{liu_wang-li_beasley_shah_2011, title={Validation and uncertainty analysis of an ammonia emission model for broiler litter}, volume={54}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79959799571&partnerID=MN8TOARS}, number={3}, journal={Transactions of the ASABE}, author={Liu, Z. and Wang-Li, L. and Beasley, D.B. and Shah, S.B.}, year={2011}, pages={1051–1057} }
 @article{li_wang_oviedo-rondon_parnell_2010, title={Effect of ozonation on particulate matter in broiler houses}, volume={89}, ISSN={["1525-3171"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77958110285&partnerID=MN8TOARS}, DOI={10.3382/ps.2010-00712}, abstractNote={The effects of ozonation on particulate matter were studied on a commercial broiler farm. The farm consisted of 4 identical tunnel-ventilated houses (12.8×152.4 m): 2 houses were treated with O3 (maximum concentration 0.1 ppm) and the other 2 served as control units. The particle size distributions of total suspended particulate (TSP) samples from both control and treated houses were found to have very similar profiles with no statistical difference. The TSP concentrations were significantly higher in treated houses as compared with those in control houses, and the mean of the differences was 5.50 mg/m3. In both treated and control houses, there were substantial vertical TSP concentration gradients and the concentrations decreased with height. At broiler chicken height (0.28 m), TSP concentrations were 13±3 mg/m3 in control houses and 17±2 mg/m3 in treated houses. At human breathing height (1.55 m), TSP concentrations were 8±4 mg/m3 in control houses and 7±2 mg/m3 in treated houses. Particle phase NH4+ concentrations were higher in treated houses (ranging from 0.59 to 42.01 mg/m3 with mean=17.49 mg/m3) than in control houses (ranging from 0.34 to 13.55 mg/m3 with mean=4.42 mg/m3). The TSP samples from locations in the vicinity of the farm showed higher concentrations downwind than that upwind, but there were no significant differences observed among different ambient locations for TSP NH4+ concentrations. The results from this study did not show that direct application of ozonation technique has beneficial effects for particulate matter control in broiler houses.}, number={10}, journal={POULTRY SCIENCE}, author={Li, Q. and Wang, L. and Oviedo-Rondon, E. and Parnell, C. B.}, year={2010}, month={Oct}, pages={2052–2062} }
 @article{wang_oviedo-rondon_small_liu_sheldon_havenstein_williams_2010, title={Farm-Scale Evaluation of Ozonation for Mitigating Ammonia Concentrations in Broiler Houses}, volume={60}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77955613072&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.60.7.789}, abstractNote={Abstract This study evaluated the effectiveness of in-house ozonation within the public health standard limit (0.1 parts per million [ppm]) for mitigating ammonia (NH3) concentrations inside commercial broiler houses. The project was conducted in four identical tunnel-ventilated houses. Two houses served as treatment and the other two served as control units. The experiment was replicated in five consecutive flocks. Except for ozonation treatment, all other operational parameters including feed, broiler strain, age and number of broilers, and ventilation system were the same among four houses. NH3 and carbon dioxide (CO2) concentrations in the treatment and control houses were measured for a minimum of 48 hr/week throughout the five flocks of 8 or 9 weeks each. The gas measurements were conducted using portable multigas units (PMUs). House temperatures were recorded with data loggers in each flock. Comparison of temperatures and CO2 concentrations among houses indicated no significant differences in ventilation rates among treatment and control houses in any of the five flocks. As a result, comparisons of NH3 concentrations inside houses were used to evaluate the effectiveness of house ozonation for NH3 emission mitigation. Statistical test of mean NH3 concentrations for each flock separated by house indicated that the house-to-house variation was significantly smaller than the flock-to-flock variation. There was a substantial variation in NH3 concentrations across different flocks, but no house had consistently higher or lower mean NH3 concentrations than any other. Evaluations for differences in mean NH3 from week to week, between treatment groups, and differences in week-to-week variations between treatment groups suggested that ozone effect was not uniform for each week and the effect was not statistically significant for any week. Tests of overall ozone treatment effect and treatment-week interaction indicated there was no difference in mean NH3 between the control and ozone treatment groups (P = 0.25), nor was the week effect different for control and treatment groups (P = 0.46). The results of this field evaluation indicate that there was no statistical evidence to suggest that the ozone treatment has any effect on average NH3 concentrations in these chicken houses.}, number={7}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Wang, Lingjuan and Oviedo-Rondon, Edgar O. and Small, John and Liu, Zifei and Sheldon, Brian W. and Havenstein, Gerald B. and Williams, C. Mike}, year={2010}, month={Jul}, pages={789–796} }
 @article{li_wang_liu_kamens_2009, title={Could ozonation technology really work for mitigating air emissions from animal feeding operations?}, volume={59}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70449729852&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.59.10.1239}, abstractNote={Abstract Among various mitigation technologies for ammonia (NH3) emission control at animal feeding operations (AFOs), room ozonation technology is the most controversial. This paper aims to present full perspectives of ozonation techniques through a literature review and a series of laboratory experiments. In the literature review, ozone chemistry was summarized to address (1) ozone and NH3 reactions, (2) ozone and odor reactions, (3) ozone and particulate matter reactions, and (4) ozone and microorganism reactions. A series of laboratory experiments were conducted in a dual large outdoor aerosol smog chamber (270 m3). NH3 and fine particle number concentrations from ozone-treated and control experiments were compared. The experimental results indicated that (1) ozone has no significant effect on NH3 emissions concentrations or NH3 decay of an outdoor chamber; and (2) with ozone treatment, high concentration of particles in the “high-risk” respiratory fraction (in submicron range) are generated.}, number={10}, journal={Journal of the Air and Waste Management Association}, author={Li, Q. and Wang, L. and Liu, Z. and Kamens, R.M.}, year={2009}, pages={1239–1246} }
 @article{liu_wang_beasley_shah_2009, title={Modeling ammonia emissions from broiler litter at laboratory scale}, volume={52}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70449638099&partnerID=MN8TOARS}, DOI={10.13031/2013.29131}, abstractNote={The objectives of this study were to develop a mechanistic emission model to estimate ammonia flux from broiler litter and to evaluate the model at laboratory scale. In the proposed model, the ammonia flux is essentially a function of the litter's total ammoniacal nitrogen (TAN) content, moisture content, pH, and temperature, as well as the Freundlich partition coefficient (Kf), mass transfer coefficient (KG), ventilation rate (Q), and emission surface area (A). The Freundlich partition coefficient (Kf) was used as a fitting parameter in the model. A dynamic flow-through chamber system and a wind tunnel were designed to measure ammonia fluxes from broiler litter. The dynamic flow-through chamber experiments evaluated the proposed model with various litter samples under a constant temperature and wind profile. The wind tunnel experiments evaluated the proposed model under various temperatures and wind profiles. Model parameters such as Kf and KG were estimated. The results from the two experiments were consistent with each other. The estimated KG ranged from 1.11 to 27.64 m h-1, and the estimated Kf ranged from 0.56 to 4.48 L kg-1. A regression sub-model was developed to estimate Kf as function of litter pH and temperature, which indicated that Kf increased with increasing litter pH and decreased with increasing temperature. The proposed model was used to estimate the equilibrium gas phase ammonia concentration (Cg,0) in litter, and the model-predicted values were compared with the observed values. The normalized mean error (NME), the normalized mean square error (NMSE), and fractional bias (FB) were calculated to be 25%, 12%, and -0.3%, respectively, for all 94 measurements, and the model was able to reproduce 80% of the variability of the data. Sensitivity analysis of the model showed that ammonia flux is very sensitive to litter pH and to a lesser extent temperature. The relative sensitivity of pH or temperature increases as the pH or temperature increases.}, number={5}, journal={Transactions of the ASABE}, author={Liu, Z. and Wang, L. and Beasley, D. B. and Shah, Sanjay}, year={2009}, pages={1683–1694} }
 @article{park_rock_wang_seo_bhatnagar_kim_2009, title={Performance evaluation of six different aerosol samplers in a particulate matter generation chamber}, volume={43}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-57949096309&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2008.09.028}, abstractNote={The present study was carried out with the aim of evaluating the performance of six different aerosol samplers in terms of mass concentration, particle size distribution, and mass fraction for the international size-sampling conventions. The international size-sampling criteria were defined as inhalable, thoracic, and respirable mass fractions with 50% cutoff at an aerodynamic equivalent diameter of 100 μm, 10 μm, and 4 μm, respectively. Two Andersen, four total suspended particulate (TSP), two RespiCon, four PM10, two DustTrak, and two SidePak samplers were selected and tested to quantitatively estimate human exposure in a carefully controlled particulate matter (PM) test chamber. The overall results indicate that (1) Andersen samplers underestimate total suspended PM and overestimate thoracic and respirable PM due to particle bounce and carryover between stages, (2) TSP samplers provide total suspended PM as reference samplers, (3) TSP samplers quantified by a coulter counter multisizer provide no information below an equivalent spherical diameter of 2 μm and therefore underestimate respirable PM, (4) RespiCon samplers are free from particle bounce as inhalable samplers but underestimate total suspended PM, (5) PM10 samplers overestimate thoracic PM, and (6) DustTrak and SidePak samplers provide relative PM concentrations instead of absolute PM concentrations.}, number={2}, journal={Atmospheric Environment}, author={Park, J.-M. and Rock, J.C. and Wang, L. and Seo, Y.-C. and Bhatnagar, A. and Kim, S.}, year={2009}, pages={280–289} }
 @inproceedings{liu_wang_beasley_2008, title={Comparison of three techniques for determining ammonia emission fluxes from broiler litter}, volume={51}, DOI={10.13031/2013.25304}, abstractNote={This article reports an experimental study of three techniques in ammonia emission flux determination. Ammonia concentrations in a dynamic flow-through chamber with broiler litter were measured simultaneously by a chemiluminescence ammonia analyzer and an acid scrubber. At the beginning and ending of each test, the litter samples were analyzed for conducting nitrogen mass balance. Ammonia emissions were estimated from the two concentration measurements and the mass balance approach. It was observed that the chemiluminescence analyzer measurements tended to overestimate ammonia concentration compared with the acid scrubber measurements, especially when litter moisture was high. Statistical results indicated that the effect of litter moisture content on the ratios of the average chemiluminescence analyzer measurements over the acid scrubber measurements was significant, and a p-value of 0.0104 was obtained. Great uncertainties were observed for the mass balance approach, especially when the percentages of the total nitrogen losses in litter samples were small (less than 2%). In order to apply the mass balance approach to estimate ammonia emissions and to achieve acceptable accuracy, a substantially long testing period (more than 80 h) is needed under the observed ammonia emission level (104 to 1137 mg N h-1 m-2), and great efforts are needed to reduce the uncertainties associated with sampling and analyzing litter nitrogen content.}, number={5}, booktitle={Transactions of the ASABE}, author={Liu, Z. and Wang, L. and Beasley, D. B.}, year={2008}, pages={1783–1790} }
 @article{liu_wang_beasley_2008, title={Comparison of three techniques for determining ammonia emission fluxes from broiler litter}, volume={51}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-55249113187&partnerID=MN8TOARS}, number={5}, journal={Transactions of the ASABE}, author={Liu, Z. and Wang, L. and Beasley, D.B.}, year={2008}, pages={1783–1790} }
 @article{buser_whitelock_holt_armijo_wang_2007, title={Collection efficiency evaluation of baffle-type pre-separator configurations: Effects of baffle location and inlet velocities}, volume={23}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34347213029&partnerID=MN8TOARS}, DOI={10.13031/2013.22682}, abstractNote={Some cotton gins across the Cotton Belt use an abatement system consisting of a baffle-type pre-separator followed by cyclones to control the emissions from the cotton gin's various exhausts. Very limited information exists in the literature which discusses the effects of baffle location and critical velocity on the pre-separator's collection efficiency. In this study, a range of critical air velocities and loading rates were evaluated to determine the effect of baffle location of the pre-separator's collection efficiency when using cotton gin waste. None of the treatments significantly affected the over-sized cyclone or over-all collection efficiency. The pre-separator collection efficiency was higher (81%) when the baffle placed at one-third the overall width of the pre-separator from the inlet than when placed at one-half (78%) or two-thirds (75%). The pre-separator collection efficiency was 79.4% at 18.3-m s-1 (3600-fpm) inlet velocity which was significantly higher than 78.2% at 20.3 m s-1 (4000 fpm) and 78.5% at 22.4 m s-1 (4400 fpm). Loading rate did significantly affect the pre-separator efficiency, but not to the extent of inlet velocity. The sieve analysis indicated that the pre-separator removed the majority of material larger than 180 µm; however, the pre-separator did allow a substantial amount of lint to pass through to the cyclone. The baffle-type pre-separator performed well in reducing the course material loading rate entering the cyclone.}, number={3}, journal={Applied Engineering in Agriculture}, author={Buser, M.D. and Whitelock, D.P. and Holt, G.A. and Armijo, C.B. and Wang, L.}, year={2007}, pages={347–355} }
 @article{liu_wang_beasley_oviedo_2007, title={Effect of moisture content on ammonia emissions from broiler litter: A laboratory study}, volume={58}, ISSN={["1573-0662"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34548108638&partnerID=MN8TOARS}, DOI={10.1007/s10874-007-9076-8}, number={1}, journal={JOURNAL OF ATMOSPHERIC CHEMISTRY}, author={Liu, Zifei and Wang, Lingjuan and Beasley, David and Oviedo, Edgar}, year={2007}, month={Sep}, pages={41–53} }
 @article{wang_parnell_buser_2007, title={Theoretical study of the impact of particulate matter gravitational settling on ambient coarse particulate matter monitoring for agricultural emissions}, volume={57}, ISSN={["1047-3289"]}, DOI={10.1080/10473289.2007.10465300}, abstractNote={Abstract The particle size distributions (PSDs) of particulate matter (PM) in the downwind plume from simulated sources of a cotton gin were analyzed to determine the impact of PM settling on PM monitoring. The PSD of PM in a plume varies as a function of gravitational settling. Gravitational settling has a greater impact on the downwind PSD from sources with PSDs having larger mass median diameters (MMDs). The change in PSD is a function of the source PSD of emitted PM, wind speed, and downwind distance. Both MMD and geometric standard deviation (GSD) in the downwind plume decrease with an increase in down-wind distance and source MMD. The larger the source MMD, the greater the change in the downwind MMD and GSD. Also, the greater the distance from the source to the sampler, the greater the change in the downwind MMD and GSD. Variations of the PSD in the downwind plume significantly impact PM10 sampling errors associated with the U.S. Environmental Protection Agency (EPA) PM10 samplers. For the emission sources with MMD >10 µm, the PM10 oversampling rate increases with an increase in downwind distance caused by the decrease of GSD of the PSD in the downwind plume. Gravitational settling of particles does not help reduce the oversampling problems associated with the EPA PM10 sampler. Furthermore, over-sampling rates decrease with an increase of the wind speed.}, number={1}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Wang, Lingjuan and Parnell, Calvin B., Jr. and Buser, Michael D.}, year={2007}, month={Jan}, pages={111–115} }
 @article{wang_parnell_shaw_lacey_2006, title={A theoretical approach for predicting number of turns and cyclone pressure drop}, volume={49}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33646836825&partnerID=MN8TOARS}, DOI={10.13031/2013.20404}, abstractNote={A new theoretical method for computing travel distance, number of turns, and cyclone pressure drop has been 
developed and is presented in this article. The flow pattern and cyclone dimensions determine the travel distance in a cyclone. 
The effective number of turns was calculated based on the travel distance. Cyclone pressure drop is composed of five pressure 
loss components. The frictional pressure loss is the primary pressure loss in a cyclone. This new theoretical analysis of cyclone 
pressure drop for 1D2D, 2D2D, and 1D3D cyclones was tested against measured data at different inlet velocities and gave 
excellent agreement. The results show that cyclone pressure drop varies with the inlet velocity, but not with cyclone diameter.}, number={2}, journal={Transactions of the ASABE}, author={Wang, L. and Parnell, C.B. and Shaw, B.W. and Lacey, R.E.}, year={2006}, pages={491–503} }
 @article{wang_parker_parnell_lacey_shaw_2006, title={Comparison of CALPUFF and ISCST3 models for predicting downwind odor and source emission rates}, volume={40}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33745924435&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2006.04.043}, abstractNote={CALPUFF model and ISCST3 Gaussian dispersion models were evaluated for predicting downwind odor concentrations and back-calculating area source odor emission rates. The comparison between the predicted and field-sampled downwind concentrations indicates that the CALPUFF model could fairly well predict average downwind odor concentrations. However, ISCST3 tended to under predict downwind odor concentrations as compared to the measured concentrations. Both the CALPUFF and ISCST3 models failed to predict peak odor concentrations using the constant average emission rate. Odor emission rates obtained by back-calculating fluxes using CALPUFF and ISC models with the same field measurements of downwind odor concentrations are significantly different. It indicates that back-calculated emission rates are model specific. The modeled emission rates tended to be higher than flux chamber source sampling results. The flux chamber protocol may under-estimate odor emission rates.}, number={25}, journal={ATMOSPHERIC ENVIRONMENT}, author={Wang, Lingjuan and Parker, David B. and Parnell, Calvin B. and Lacey, Ronald E. and Shaw, Bryan W.}, year={2006}, month={Aug}, pages={4663–4669} }
 @article{wang_parnell_shaw_lacey_buser_goodrich_capareda_2005, title={Correcting PM<inf>10</inf> over-sampling problems for agricultural particulate matter emissions: Preliminary study}, volume={48}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-20044396383&partnerID=MN8TOARS}, DOI={10.13031/2013.18317}, abstractNote={The Federal Reference Method (FRM) ambient PM10 sampler does not always measure the true PM10 
concentration. There are inherent sampling errors associated with the PM10 samplers due to the interaction of particle size 
distribution (PSD) and sampler performance characteristics. These sampling errors, which are the relative differences 
between theoretical estimation of the sampler concentration and the true concentration, should be corrected for equal 
regulation between industries. An alternative method to determine true PM10 concentration is to use the total suspended 
particulate (TSP) concentration and PM10 fraction of the PSD in question. This article reports a new theoretical method to 
correct PM10 sampling errors for a true PM10/TSP ratio. The new method uses co-located PM10/TSP samplers’ measurements 
to derive the mass median diameter (MMD) of PSD and true PM10/TSP ratio. Correction equations and charts have been 
developed for the PMs with GSDs of 1.2, 1.3, ..., 2.1, respectively, and the PM10 sampler with a cutpoint of 10 .m and slope 
of 1.5. These equations and charts can be used to obtain a corrected PM10/TSP ratio for the given GSD and sampler 
characteristics. The corrected PM10/TSP ratio will be treated as the true PM10/TSP ratio for PM10 concentration 
calculations. This theoretical process to obtain a corrected PM10/TSP ratio will minimize the inherent PM10 sampler errors 
and will provide more accurate PM10 measurement for the given conditions.}, number={2}, journal={Transactions of the American Society of Agricultural Engineers}, author={Wang, L. and Parnell, C.B. and Shaw, B.W. and Lacey, R.E. and Buser, M.D. and Goodrich, L.B. and Capareda, S.C.}, year={2005}, pages={749–755} }
 @article{wang_wanjura_parnell_lacey_shaw_2005, title={Performance characteristics of a low-volume PM10 sampler}, volume={48}, DOI={10.13031/2013.18316}, abstractNote={Four identical PM10 pre-separators, along with four identical low-volume (1 m3 h-1) total suspended particulate 
(TSP) samplers were tested side-by-side in a controlled laboratory particulate matter (PM) chamber. The four PM10 and four 
TSP samplers were also tested in an oil pipe cleaning field to evaluate the PM10 samplers’ performance characteristics. The 
PMs used in the chamber tests had mass median diameters (MMDs) larger than 10 .m, whereas the PM emitted from the oil 
pipe cleaning system for the field tests had MMD smaller than 10 .m. The co-located TSP and PM10 sampler testing results 
indicate that PM10 samplers over-sample when exposed to ambient PM having MMD larger than 10 .m aerodynamic 
equivalent diameter (AED) and under-sample when exposed to ambient PM with MMD smaller than 10 .m. The 
over-sampling and under-sampling rates varied with the change of MMD and the PM loading (TSP concentration). The 
cutpoints and slopes of the PM10 pre-separator changed with the change of MMD of inlet PM.}, number={2}, journal={Transactions of the ASAE}, author={Wang, L. J. and Wanjura, J. D. and Parnell, C. B. and Lacey, R. E. and Shaw, B. W.}, year={2005}, pages={739–748} }
 @article{wang_wanjura_parnell_lacey_shaw_2005, title={Performance characteristics of a low-volume PM<inf>10</inf> sampler}, volume={48}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-20044366574&partnerID=MN8TOARS}, number={2}, journal={Transactions of the American Society of Agricultural Engineers}, author={Wang, L. and Wanjura, J.D. and Parnell, C.B. and Lacey, R.E. and Shaw, B.W.}, year={2005}, pages={739–748} }
 @article{wang_buser_parnell_shaw_2003, title={Effect of Air Density on Cyclone Performance and System Design}, volume={46}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0242287217&partnerID=MN8TOARS}, number={4}, journal={Transactions of the American Society of Agricultural Engineers}, author={Wang, L. and Buser, M.D. and Parnell, C.B. and Shaw, B.W.}, year={2003}, pages={1193–1201} }