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HighlightsSingle kernel mass and particle density were not significantly affected by the number of rice weevils feeding within a corn kernel and lesser grain borers feeding within a wheat kernel.In both corn and wheat, single kernel mass decreased after the larval stage of internally feeding insects.Particle density increased linearly with insect age for both rice weevils in corn and lesser grain borer in wheat.The increasing particle density while the kernel mass was being eroded indicates that the kernel internal void was detected by the gas pycnometer employed for measurement of the true volume of grain kernels.Abstract. To model the dynamics of insect infestation in a grain handling system using the discrete element method (DEM), physical properties of the infested kernels compared to their sound counterparts are needed, specifically particle density and single kernel mass of infested kernels. Thus, the objective of this study was to determine the particle density and single kernel mass of internally infested kernels as affected by insect age. Corn and wheat were infested with internal feeders: rice weevil (RW), Sitophilus oryzae (L.), in corn and lesser grain borer (LGB), Rhyzopertha dominica (F.), in wheat. The internal feeders were allowed to grow and mature inside the kernels and properties were measured for representative samples selected using X-ray imaging approximately 14, 28, 35, and 42 days after the end of a 4-day oviposition period. The measured kernel physical properties were not affected by the number of internal insects per kernel. In both corn and wheat, single kernel mass decreased after the larval stage of internally feeding insects. Single kernel mass decreased from 374 mg in sound corn to 346 mg in corn with pre-emerged RW adults and from 31.4 mg in sound wheat to 25.9 mg in wheat with pre-emerged LGB adults. Particle density increased with insect age for both RW in corn and LGB in wheat with a linear trend. The increasing particle density while the kernel mass eroded indicates that kernel internal void was detected by the gas pycnometer employed for measurement of the true volume of grain kernels. Data obtained from this study enables effective DEM modeling of grain commingling of insect-infested and sound grain kernels in grain handling systems. Keywords: Corn, Insect age, Internal feeders, Insect infestation, Lesser grain borer, Particle density, Rice weevil, Single kernel mass, Wheat.

HighlightsThe predicted bulk density of two wheat varieties varied with drop height, similar to the experiments.The percentage composition of three kernel size fractions in the wheat varieties affected the bulk density.Accurate particle shape representation simulated the heap profile better but required longer computational time.The single-sphere model is more practical to use because of its higher accuracy and lower computational cost.Abstract. Grain bulk density varies widely depending on kernel properties and handling practices. The discrete element method (DEM) can model such behavior at the particle level, including wide-ranging interactions with equipment. The objective of this study was to develop a DEM model to predict wheat bulk density as affected by grain drop height and kernel size distribution. The bulk density of two wheat varieties was measured experimentally for a range of drop heights with a modified test weight per bushel apparatus and was simulated in EDEM v2018.1 using single-sphere and five-sphere particle models that accounted for three kernel size fractions. For both particle models, simulations matched the observed behavior, showing a bulk density increase with increasing drop height and bulk density differences between varieties due to different kernel size fractions. The single-sphere particle model predicted the bulk density with higher accuracy than the five-sphere particle model, while the five-sphere model, which more accurately represented the shape of wheat kernels, allowed better simulation of the heap profile at the cost of longer computation time. These particle models can be used to simulate bulk density of wheat under compaction and to improve prediction models of grain pack factor for wheat. Keywords: Bulk density, DEM, Drop height, Size distribution, Wheat.

HighlightsThis study developed a mathematical relationship accounting for the production rate of phosphine.The effect of temperature on phosphine sorption into wheat is described mathematically.A computational fluid dynamics (CFD) model was built to predict the phosphine concentration in fumigated grain.Experiments were conducted to validate the CFD model.Abstract. Phosphine gas (PH3) is widely used as a fumigant for stored product insect infestations due to its relatively low price and the near absence of residual chemical on the grain. Understanding the behavior of phosphine gas inside the fumigated space is crucial to maintaining a lethal dosage and protecting stored grain from subsequent insect damage. Phosphine is available either in gas form or is produced from a solid material, as pellets or tablets, that reacts with water in the air. The solid form is the most commonly used; however, limited information is available on the rate of phosphine gas generated from the solid material. In this study, a mathematical equation was formulated, based on previous studies in the literature, to describe the gas generation rate. This equation was incorporated into a computational model using ANSYS Fluent 19.1, a commercial software for computational fluid dynamics (CFD) analysis. The computational model developed here allows prediction of the phosphine concentration within a fumigated grain bulk. The PH3 sorption was included in the model. The effect of temperature on the sorption rate was investigated based on published data, and the rate change due to temperature was characterized. The gas generated by a single pellet was measured in laboratory experiments in a 0.208 m3 sealed barrel. The measurements confirmed the CFD results with an error of 0.3%, 0.9%, and 7.2% for three different configurations. The deviations seen between the experimental replicates increased the error and show the need for further investigation of the effects of temperature, grain age and history, leakage, and other factors. Keywords: CFD, Evolution rate, Phosphine, Sorption.

Water-solid interactions play a key role in determining the efficacy of inert dusts. The critical water activity (Awc) for phase transition in amorphous materials is an important characteristic of amorphous inert dusts used as grain protectants. As water activity (Aw) rises above Awc, amorphous dusts undergo a transition from glassy or vitreous state to rubbery state. Such a transition induces dramatic changes in material properties, texture and structure, and hence impact their performance as grain protectants. Full Dynamic Dewpoint Isotherms (DDI) of a synthetic amorphous zeolite intended for grain protection were generated using the Vapor Sorption Analyzer (VSA) to determine Awc by investigating the relationship between moisture content and Aw at constant temperatures. Sorption experimental data was fitted using three sorption isotherm models: Guggenheim-Anderson-de Boer (GAB), Double Log Polynomial (DLP), and Brunauer-Emmet-Teller (BET). DLP model was the best model to estimate zeolite and wheat sorption isotherms. Full sorption isotherms of zeolite and wheat obtained at 25, 35, and 45 °C clearly showed the hysteresis phenomenon. The hysteresis loops were of type H3 for wheat, and of type H4 for zeolite powder. The intensity of hysteresis remained unchanged for wheat. However, the intensity of hysteresis decreased with increasing temperatures during water adsorption by porous zeolite powder. Monolayer moisture content values for each sorption direction were provided only by GAB and BET models and indicated a decrease in monolayer moisture content with an increase in temperature. The net isosteric heats of sorption and the differential enthalpy of zeolite estimated by the Clausius–Clapeyron equation and determined graphically decreased with increasing moisture content. Conversely, differential entropy of zeolite decreased with increasing zeolite moisture content. The optimal moisture content of inert dust for grain treatment was dependent on wheat moisture content and wheat storage temperature. This is the first time that a synthetic amorphous dust is being investigated for grain protection. Our results recommend the application of inert dusts at the optimal moisture content to mitigate moisture migration within the system “wheat-dust”, thus ensuring dust maximal efficacy.

HighlightsFreshly harvested, higher quality corn samples have a higher proportion of small dust particles with a lower circularity and aspect ratio compared to older, lower quality samples.For freshly harvested grain, dust particles removed at low centrifuge speed were significantly rougher than particles removed at high speed.Lower quality corn did not show a significant decrease in particle roughness for strongly attached dust.The surface area decreased while the surface energy increased with the attachment strength of dust particles.Abstract. High dust concentrations associated with grain handling can cause serious problems, including health and safety risks from dust inhalation and increased risk of explosions due to contained suspended dust in the presence of an ignition source. The amount of dust generated during grain handling is influenced by several factors, including the adhesion strength of dust to the grain. One factor that could influence the adhesion strength of grain dusts is how the dust particles are shaped and how their shape relates to the surface texture of corn. To better understand the properties of dust particles separated from corn samples, dust samples were analyzed for morphology and particle size. In addition, dust samples were separated with different centrifugation speeds to compare the properties of dusts that were strongly or weakly attached to the grain. These samples were observed with a light profilometer to measure their surface roughness characteristics. Results showed that freshly harvested corn samples contained a higher presence of small particles with low circularity than older, lower quality samples. The large particles observed were determined to be starch, as opposed to the smaller particles that were more likely soil or other non-plant-based material. The dust particles that were more strongly attached to corn kernels tended to have lower surface roughness than those that were weakly attached for the freshly harvested grain. Keywords: Dust adhesion, Particle shape, Surface adhesion, Surface roughness.

HighlightsThe corn sample and centrifuge speed interactions were statistically significant predictors of dust generation.Attachment strengths of dust particles were calculated, with forces ranging from less than 4.6 × 10-10 N to 2.1 × 10-8 N.A sequential centrifuge experiment indicated a bimodal distribution of adhesion forces.Abstract. Grain dust explosions are a constant threat to the grain handling industry. Explosions occur when dust accumulates beyond the minimum explosion concentration in a confined area and is exposed to an ignition source. Handling and grain unloading conditions that generate dust, the minimum explosive dust concentration, overpressure from an explosion, and other factors that lead to grain dust explosion are well documented in the literature. The adhesion force that holds grain dust particles to the grain itself is an important factor in better understanding and mitigating dust separation from grain kernels and the resulting dust cloud generation. However, that adhesion force, how it is affected by grain quality, and how it is influenced by particle factors such as size and shape has not been adequately researched. A centrifuge separation technique was used to study the adhesion forces of grain dust. Results showed large variability in dust concentration between the five corn samples tested in this study. The dust particle attachment strength ranged from less than 4.6 × 10-10 N to 2.1 × 10-8 N. Only the sample and centrifuge speed interaction had a statistically significant effect on dust concentrations recovered at a 5% confidence limit. Under repeated centrifugations, the dust removed showed a bimodal distribution of attachment strengths, with three of four samples tested showing a local minimum at 2000 rpm, and the other at 3000 rpm. This study improves the understanding of the fundamental attachment strength behind dust separation from grain kernels. Investigating the size, shape, and surface characteristics of dust particles with varying attachment strengths is important to further understand their adhesion and separation mechanisms. Keywords: Adhesion strength, Dust explosion, Dust mitigation, Grain dust, Grain handling.

HighlightsHandheld sprayers generated larger droplets and wider droplet size distributions than compressed gas sprayers.Sprayers with higher pressure and nozzles with wider spray angle produced smaller droplets.Droplet size distribution influenced spray coverage, mass concentration, deposition, and sprayer efficacy.The handheld sprayers had less spray coverage and efficiency than the compressed gas sprayers.The deposition at different locations was influenced by the volume of the space, aerosol dosage, and spray time.Abstract. Aerosol insecticides, including pyrethrins, can be used as methyl bromide replacements to control stored product insects inside flour mills and rice mills. The effectiveness of aerosol application for insect control requires knowing the spray characteristics of the equipment to be used and understanding factors that influence the effectiveness of insecticide application. The objectives of this study, as part of efforts to optimize aerosol applications, were to evaluate the characteristics of six aerosol delivery systems (two handheld sprayers and compressed gas sprayer systems fitted with two types of manifolds and two types of nozzles), estimate the dispersion and deposition of aerosol in a simulated stored product facility, and determine how the dispersion and deposition are affected by the characteristics of the sprayers. Results showed that the spray systems differed significantly in spray characteristics. The compressed gas sprayers generated significantly smaller droplets, more uniform droplet size distribution, and better spray coverage than the handheld sprayers. The ellipsoidal nozzle produced significantly smaller droplets than the circular nozzle. While the type of manifold had no significant effect on deposition, higher aerosol dosage and spray time resulted in significantly higher deposition. Results of this study will be used to improve spray techniques for stored product insect control, to validate computational fluid dynamics modeling of aerosol application, and to improve testing methods in large-scale spray testing inside commercial facilities. Keywords: APS spectrometer, Droplet size distribution, HELOS KR-Vario, Mass deposition, Spray characteristics, Spray nozzles.

HighlightsDecreasing aspect ratio and improved geometrical smoothness of particles increased DEM-predicted bulk density of wheat.Among the three particle models, the 5-sphere ellipsoidal particle was the best option to represent wheat particles, as indicated by the simulated bulk densities that best agreed with the experiments.Among the contact parameters, the wheat-to-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the greatest influence on simulated bulk density.Abstract. The discrete element method (DEM) has been shown to be an effective tool for simulating the behavior of granular material. The accuracy of simulations depends highly on the contact models, particle physical parameters, and contact parameters used. The objectives of this study were to determine the influence of particle shape and contact parameters on simulated wheat bulk density and to develop an effective wheat particle model for DEM simulation of filling a container using EDEM software. Grain characteristics, including single-kernel weight, kernel density, kernel dimensions, aspect ratio, and bulk density, were determined for three size fractions of wheat used in the experiments. Three categories of particle models (5-sphere pseudo-ellipsoidal, 7-sphere pseudo-ellipsoidal, and ASG-generated) with varying aspect ratios and geometrical smoothness were tested in the simulations. Results showed that DEM-simulated bulk density of wheat increased with lower aspect ratio and greater geometrical smoothness of pseudo-ellipsoidal particles (7-sphere versus 5-sphere). Increasing the number of spheres to approximately 30 for better representation of wheat kernel shape, using ASG-generated particles, did not reproduce the trend of greater simulated bulk density seen in the experiments. Among the six contact parameters, the wheat-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the most significant effect on the simulated bulk density. Among the different sets of particle models, the 5-sphere pseudo-ellipsoidal particles, having aspect ratios close to that of wheat kernels in each size fraction, were found to be the most practical and appropriate particle model for use in DEM simulation of wheat bulk density. This study contributes to better understanding of the influence of particle shape and contact parameters on DEM-simulated bulk density and provides a calibrated particle model for use in simulating container filling operations. Keywords: Bulk density, Contact parameters, DEM, Particle shape, Wheat.

Previous research has shown that particulate matter (PM) in the air can be captured by vegetative barriers (VB) serving as shelter against the wind; however, there is only limited research of factors affecting their efficiency. This study used computational fluid dynamics to predict particle collection efficiency (CE) of VBs, as affected by hedge geometry (i.e., the size expressed in terms of height, depth, and leaf surface area density [LSAD]) and the number of hedgerows. The experimental data of Tiwary et al. (Journal of Aerosol Science, 2005) were used for model parametrisation. The area of wind speed reduction, protection area and mean collection efficiency were defined and calculated to evaluate the effectiveness of VBs on sheltering function and particle collection. Simulation results predicted that compared with original size, increasing the height and LSAD of the hedge resulted in a greater decrease of wind speed. Increasing the depth of the hedge had the greatest effect on particle collection with 42.4% for dp = 15 μm, more effective than increasing the height or LSAD. Adding another row of hedge also increased the capability of the hedge in wind speed reduction and particle collection, while row spacing did not show great effect. The increasing rate of mean CE by adding a hedgerow was less than that by increasing hedge size, which more than double the CE of particles with diameter greater than 4.25 μm. Field measurements and additional simulation tests need to be conducted under different conditions for model validation.

Monitoring the temperature of stored grain with permanent cables suspended from the bin roof is common practice in commercial grain storage and is sometimes used in on-farm grain storage bins. Knowledge of the forces imparted on the cables by flowing grain is required for proper design of cables, connection hardware, and bin roofs, but there is little data in the literature for full size bins. To determine forces on different cable sizes and configurations, five different cable designs were tested during filling and emptying of wheat and corn. Two concrete storage bins, 4.6-m diameter and 25-m maximum depth, were used with cables suspended from the center of the bin or suspended 0.6 m from the sidewall. The bottom ends of the cables were weighted, but were not fully restrained. Forces on the cables were monitored during filling and emptying of the bins. Forces during emptying usually exhibited slip-stick behavior. The greatest forces were during emptying, where forces were often double those during filling, with vertical forces up to 4.7 kN for the largest cable. Both peak and average forces for bin emptying were significantly larger than corresponding forces for bin filling. Results showed no effect of grain type (corn or wheat) while cable size had significant effects on peak and average force in most cases. Keywords: Corn, Design load, Force, Grain bin, Temperature monitoring cable, Wheat.

Maintaining vegetative cover on the soil surface is the most widely used method for control of soil loss by wind erosion. We numerically modeled airflow through artificial standing vegetation (i.e., simulated wheat plants) using computational fluid dynamics (CFD). A solver (simpleFoam within the OpenFOAM software architecture) was used to simulate airflow through various three-dimensional (3D) canopy structures in a wind tunnel, which were created using another open-source CAD geometry software (Salomé ver. 7.2). This study focused on two specific objectives: (1) model airflow through standing vegetation using CFD, and (2) compare the results of a previous wind tunnel study with various artificial vegetation configurations to the results of the CFD model. Wind speeds measured in the wind tunnel experiment differed slightly from the numerical simulation using CFD, especially near positions where simulated vegetation was present. Effective drag coefficients computed using wind profiles did not differ significantly (p HighlightsMeasured airflow through a simulated canopy was successfully modeled using CFD software.Effective drag coefficients did not differ between the experimental and simulated results.Results of this study provide 3-D simulation data of wind flow through a plant canopy. Keywords: 3-D canopy structure, OpenFOAM, Wind erosion, Wind tunnel studies.

Prescribed range/pasture burning is a common practice in Kansas to enhance the nutritional value of native grasses and control invading weeds, trees, and brush. A major concern associated with the burning is the contribution of smoke to elevated ground level ambient ozone (O3). The objective of this study is to estimate contributions of Kansas rangeland burning to ambient O3 mixing ratios through regression analysis (1) between observed O3 data and available satellite burn activity data from 2001 to 2016; and (2) between observed O3 data and the smoke contributions to PM2.5 which were resolved from receptor modeling. Positive correlations were observed between ambient O3 levels and the acres burned each year estimated from satellite imagery. When burned acres in April were larger than or equal to 1.9 million, O3 > 70 ppb occurred at least at one of the ten monitoring sites in Kansas. Statistical regression models of daily maximum 8-hour O3 mixing ratios were developed at each of the ten monitoring sites using meteorological predictors. The O3 model residuals that were not explained by the meteorological effect models were affected by PM2.5 contributors including sulfate/industrial sources and emissions that generated secondary organic particles, such as rangeland burning, which were derived from receptor modeling. The average O3 model residual on the high O3 days in April was 21 ± 9 ppb, which was likely associated with smoke emissions from burning. Research will continue to obtain daily satellite burn activity data and to correlate burn data with daily O3 data, so that modeling of O3 levels can be improved under influences of daily burn activities. Less frequency of high O3 days was observed in April since 2011, which may be partly due to implementation of the Flint Hills Smoke Management Plan which promoted better timing of burns.

Grain and oilseed crops stored in bins undergo compaction due to overbearing pressure of the grain inside the structure. Thus, volume measurements of grain in bins need to be combined with the amount of packing (usually called pack factor) in addition to the initial density so that the mass in the structure can be calculated. Multiple pack factor prediction methods are in use in the grain industry, but they have only been validated in the literature and compared with field data for corn and hard red winter wheat. Predictions from WPACKING, the program in ASABE Standard EP413.2, and two standard USDA methods, the USDA Risk Management Agency (RMA) and USDA Farm Service Agency-Warehouse Licensing and Examination Division (FSA-W) methods, were compared to field measurements of 92 bins containing soybeans, grain sorghum, oats, barley, or soft white or durum wheat. The WPACKING predictions had the lowest absolute average error of predicted mass for soybeans, grain sorghum, barley, and wheat, while the FSA-W method had the lowest error for oats. The RMA method gave the largest prediction errors for all five crops and struggled especially with the low-density, high-compaction crops oats and barley, giving average percent absolute errors near or above 10% in both cases. Overall, WPACKING, the RMA method, and the FSA-W method had average percent absolute errors of 2.09%, 5.65%, and 3.62%, respectively, for the 92 bins. These results can be used to improve pack factor predictions for the grain industry. Keywords: Barley, Grain, Grain sorghum, Oats, Pack factor, Sorghum, Soybeans, Steel and concrete bins, Stored grain inventory, Test weight, Wheat.

Deciduous trees of the species (Osage orange) are commonly established as vegetative barriers for wind erosion control throughout the U.S. Great Plains. Because there is no previous research on the aerodynamic effectiveness of these vegetative barriers during different seasons (leaf-on and leaf-off conditions), this study focused on determining the porosity and drag characteristics of this tree species. Digital image analyses were used to determine optical porosities that were then correlated with barrier drag coefficients. Images were taken in the field during calm wind conditions when the sunlight was suitable for digital imaging. Wind speeds were measured at different heights for a single-row Osage orange barrier using cup anemometers. Two anemometer towers were positioned relative to the barrier. One was located windward at 10H distance from the barrier; the other was located leeward and was movable to distances of 1H, 2H, 4H, 7H, 10H, 12H, 15H, and 20H from the barrier, where H is the average barrier height. The wind speeds measured in the field ranged from 4 to 7 m s-1, with lower wind speeds encountered during the leaf-off condition. As expected, wind speed reductions were greater for the leaf-on condition and ranged from 40% to 80% at 1H from the barrier, while the reduction was 20% to 38% for the leaf-off condition. The crown portion of the barrier was found to be responsible for much of the reduction. Mean values of the drag coefficient were 1.3 for the leaf-on condition, decreasing to 0.9 for the leaf-off condition of the Osage orange barrier, which corresponded to mean optical porosities of 20% and 61%, respectively Keywords: Drag coefficient, Image analysis, Osage orange, Porosity, Vegetative barrier, Wind erosion.

Little is known about the dust removal efficiency of common vegetative barriers. This study of blowing dust reduction was conducted on one of the most common vegetative barriers used for wind erosion control in Kansas and the U.S. Great Plains, the deciduous tree species (Osage orange). A dust generator and distributor were fabricated to generate dust particles for determining the dust removal efficiency of a single-row Osage orange barrier. Simultaneous upwind and downwind dust concentrations were measured using mini-vol samplers for total suspended particulates (TSP) at heights of 1.5, 3.0, 4.5, and 6.0 m above the ground. Measurements were made using two towers located at upwind and downwind distances equal to the height of the barrier. Particle size distribution (PSD) analysis of the initial generated dust showed that most particles were large (GMD = 102.8 µm), while about 5% of the dust was particulate matter less than 2.5 µm in diameter (PM2.5) and 15% was less than 10 µm (PM10). Laser diffraction analysis of particles from the sample filters was used to determine the dust reduction efficiency of the barrier. Results showed that dust reduction was significantly related to reduction in wind speed at lower heights, causing an overall decrease in dust concentration as particles passed through the barrier. Concentrations of larger particles (~100 µm) were also reduced relative to smaller particles when dust passed through the barrier. The data also showed that 4.5 m above the ground, near the crown of the canopy, was most efficient at removing the PM2.5 (15% to 54%) and PM10 (23% to 65%) fractions of the generated dust. Keywords: Generated dust, Osage orange, PM2.5, PM10, TSP, Wind erosion.

Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken kernels, were sieved using U.S. Tyler sieves #6, #7, #8, and #10, and the kernels retained on the sieves were used in the experiments. The kernel dimensional parameters and bulk sample parameters were measured, and additional derived parameters were calculated for each size fraction and variety. Packing ratio and compressibility of the size fractions and of binary and ternary mixtures of the size fractions were also determined for each variety. Packing ratio increased with larger kernel size, while compressibility decreased. Sphericity and flatness shape factor had strong positive linear relationships with packing ratio and strong negative relationships with compressibility, while elongation shape factor behaved the opposite way with packing ratio and compressibility. The higher the percentage mass of the larger kernel fraction in a mixture, the higher was its packing ratio and the lower its compressibility. The two tested varieties of wheat did not significantly differ in packing ratio and compressibility. These findings can be used in developing models for more accurate estimation of grain pack factor and to determine the mass of grain inside bins and other storage structures. Keywords: Compressibility, Packing, Shape, Size, Wheat.

The purpose of the following report was to review and present the literature focused on the topic of current industry practices of land transport of finished cattle, primarily within the United States and Canada. This review was broken down into 5 areas: (1) microclimate, (2) loading density, (3) duration of transport, (4) quality of transport, and (5) animal behavior. All of these factors play a role in animal welfare and have been shown to influence post-transport animal health and carcass quality. Certain stressors such as loading density and duration are more understood than others and are easier to manipulate, whereas other stressors, such as microclimate and human factors, require more research to fully understand the magnitude and interactions of the stressors and how to address them. Improving the overall transport process ensures the safety and well-being of the animal and the quality of the carcass, providing both an ethical and economic benefit.

Vegetative Barriers (VB) have the potential to mitigate air pollutants emitted from area sources, including concentrated Animal Feeding Operations (AFOs). However, the mechanism has not been fully investigated, thereby limiting the application of vegetation systems in practice. An experimental method with repeatable and controllable conditions was developed to measure the change of Particulate Matter (PM) concentrations at upwind and downwind of VB in the wind tunnel and observe accumulated PM on leaves with Scanning Electron Microscope (SEM), thus evaluating the ability of VB in mitigating PM emitted from AFOs. Branch-scale vegetation, clove (syzygium aromaticum) was selected because its leaves are one of the major factors affecting PM dispersion. The results show that the branch-scale barriers, as porous medium have the ability to interfere with airflow and reduce PM, which could be influenced by wind speed, particle size fraction and surface area density of clove. Moreover, clove elements could adjust to the wind and the micro structure of clove (such as the hierarchical structures of leaves) affected on the PM deposition. These results indicate that the methods developed in this study may be used to evaluate the potential of vegetation in mitigating PM from stationary sources, and some characteristics of vegetation can be further studied as bionic prototype for exploring engineering application of reducing particulates.

The objectives of this study were to identify the sources of variations in reported methane (CH4) conversion factor (Ym) for dairy and beef cattle through a meta-analytical approach, and to specifically investigate the effects of feed digestibility and intake level on Ym, as well as the alternative expression of methane conversion factor on a digestible energy basis (Dm). Results from 89 peer-reviewed journal articles published from 1992 to 2015 were compiled, and data across studies were analyzed statistically using the MIXED procedures of SAS. For housed cattle, Ym increased significantly with forage-to-concentrate ratio of feed and was also affected by breed. For grazing cattle, Ym varied by geographic region. The observed effect of forage-to-concentrate ratio of feed for housed cattle and the effect of geographic region for grazing cattle on enteric CH4 emissions could both be related to the effect of feed digestibility. Dm was affected significantly by both energy intake level and energy digestibility of feed as well as their interaction. Higher energy digestibility of feed and higher energy intake level of cattle resulted in a lower percentage of digestible energy intake being converted to CH4. Results of this study improved estimation of CH4 conversion factor according to animal husbandry practices. Compared with the Ym approach, the use of CH4 conversion factor on a digestible energy basis can better represent the large variation among diets and the effects of different dietary emission mitigation strategies.

Bulk grain angle of repose (AoR) is a key parameter for inventorying grain, predicting flow characteristics, and designing bins and grain handling systems. The AoR is defined for two cases, piling (dynamic) or emptying (static), and usually varies with grain type. The objective of this study was to measure piling angles of repose for corn, sorghum, barley, soybeans, oats, and hard red winter (HRW) wheat in steel and concrete bins in the United States. Angles were measured in 182 bins and 7 outdoor piles. The piling AoR for corn ranged from 15.7° to 30.2° (median of 20.4° and standard deviation of 3.8°). Sorghum, barley, soybeans, oats, and HRW wheat also exhibited a range of AoR with median values of 24.6°, 21.0°, 23.9°, 25.7°, and 22.2°, respectively. Angles of repose measured for the seven outdoor piles were within the ranges measured for the grain bins. No significant correlation was observed between AoR and moisture content within the narrow range of observed moisture contents, unlike previous literature based on laboratory measurement of grain samples with wider ranges of moisture content. Overall, the average measured piling AoR were lower than typical values cited in MWPS-29, but higher than some laboratory measurements.

This technical note presents the development of a new apparatus and data processing method to accurately estimate the volume of stored grain in a bin. Specifically, it was developed to account for the variability in surface topography that can occur in large diameter bins when partially unloaded. This was accomplished using a laser distance meter to create a low density point cloud, from which a surface was interpolated using ArcMap geoprocessing tools. The manually controlled and portable system was designed to hold the laser distance meter and provided a common reference point. The data from the laser distance meter was transmitted to a tablet PC via Bluetooth. Measurement of an empty hopper bottom bin (4.6 m in diameter and 6.5 m tall) demonstrated that the system was able to measure a known volume within 0.02%, and repeated measures of an empty flat bottom bin (1.8 m in diameter, and 5.7 m tall) were within 0.29% of the known volume. Two applications are presented which highlight the system‘s ability to capture complex surfaces, as well as limitations that result from fill scenarios where the field of view was limited.

Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric power plants enter the lungs and pollute the blood of urban residents leading to a burden of disease with more than 3 million premature deaths per year attributed to outdoor air pollution. Welfare losses including premature deaths associated with air pollution were about $5 trillion in 2013. A global transition to electric vehicles, and the generation of electricity without combustion emissions would improve air quality significantly and reduce greenhouse gas emissions. This transition is in progress in many parts of the world with more than 2 million electric vehicles in service in 2017. Electric bus and electric taxi sales are increasing, and many large cities have multiple programs to improve air quality. When health costs are considered, it is very appropriate for communities to take action to improve air quality and health. This work reviews and reports many positive actions that are in progress in larger cities.

Crop residues help protect topsoil from depletion and abrasion due to wind erosion. Limited studies have focused on the type and orientation of canopies that help minimize the effects of erosion by wind. In this study, a series of wind tunnel experiments was conducted to measure sand transport and abrasion energies within simulated standing vegetation. Wind speed profiles, relative abrasion energies, and rates of sand discharge were evaluated during 3 min test runs at two different vegetation heights (150 and 220 mm) for each of three densities of simulated vegetation (i.e., 100 × 200 mm, 200 × 200 mm, and 300 × 200 mm spacing). Tests were also conducted for a bare sand surface. As expected, vegetation density was directly related to threshold velocity and inversely related to sand discharge. The densest configuration (i.e., 100 × 200 mm spacing) increased the threshold velocity of bare sand from 5.9 to 10 m s-1. The presence of vegetation was found to be effective in minimizing the abrasion experienced by the standing vegetation models by lowering the saltation of sand particles that could impact the simulated plants. The coefficient of abrasion (Can), a measure of kinetic energy via the impact of saltating particles, was affected by saltation discharge, although this did not depend on wind speed. The values of Can for all configurations were significantly different (p < 0.05) from the bare sand surface . Keywords: Abrasion energy, Sand discharge, Standing vegetation, Threshold wind velocity, Wind erosion.

Citation: Bhadra, R., Casada, M. E., Boac, J. M., Turner, A. P., Thompson, S. A., Montross, M. D.,...McNeill, S. G. (2016) Correlating Bulk Density (With Dockage) And Test Weight (Without Dockage) For Wheat Samples. Applied Engineering in Agriculture. 32(6). 925-930. 10.13031/aea.32.11692

The Unmix receptor model was applied to the 2002-2014 speciated PM2.5 data from the IMPROVE site at Tallgrass National Preserve near Strong City, Kansas, to investigate the contributions of prescribed rangeland burning on local air quality. This investigation found the following five source categories that contribute to annual local ambient PM2.5: nitrate/agricultural (22%), vegetative burning (5%), secondary organic aerosol (29%), sulfate/industrial (30%), and crustal/soil (14%). In the month of April, the contributions of vegetative burning and secondary organic aerosol increased to 11% and 49%, respectively, indicating the influence of the prescribed burning season. The contribution of smoke from prescribed burning was estimated to be 1.05 μg m-3 as primary aerosols and 4.03 μg m-3 as secondary aerosols, which in total accounted for 42% of the average PM2.5 concentration in April.

This work proposes a novel, generalized model for bacterial disinfection formulated in light of a stochastic paradigm. The model⿿s formulation is based on an intensity of transition that is proportional to the product of general power functions of the bacteria⿿s number concentration and time; thus, the generalized stochastic model embodies the results obtained from our earlier models. The proposed model gives rise to linear and non-linear cases of the master equation whose solution can be obtained analytically as well as numerically via Monte Carlo simulation. Moreover, the generalized stochastic model has been validated with a specific instance of bacterial disinfection. The model⿿s analytical and numerical results are in excellent accord among themselves as well as with those obtained from our earlier models; in addition, the model⿿s results tend to describe the available experimental data reasonably well.

Nearly 600 articles were located in citation and keyword searches regarding the effects of humidity on comfort, health, and indoor environmental quality. Of these, around 70 articles reported the effects of low humidity (relative humidity ≤ 40%) and were analyzed in detail. Information in some categories was well chronicled, while other categories had significant knowledge gaps. Low humidity decreased house dust mite allergens. Due to different envelopes, generalizations could not be made for all bacteria and viruses. However, lower humidity increased virus survival for influenza. For comfort, low humidity had little effect on thermal comfort, but skin dryness, eye irritation, and static electricity increased as humidity decreased. For indoor environmental quality, low humidity had nonuniform effects on volatile organic compound emissions and perceived indoor air quality. Across many low humidity studies, ventilation rates and exposure times were noted as confounding variables. A majority of studies that ...

Citation: Turner A., M. Montross, S.G. McNeill, M.P. Sama, M.E. Casada, J.M. Boac, R. Bhadra, R.G. Maghirang, and S.A. Thompson. Modeling the compressibility behavior of hard red wheat varieties. 2016. Transaction of ASABE 59(3): 1029-10385.

Citation: Turner A., J. Jackson, N. Koeninger, S. McNeill, M. Montross, M. E. Casada, J. M. Boac, R. Bhadra, R. G. Maghirang, and S. A. Thompson. 2016. Error Analysis of stored grain inventory determination. Transactions of ASABE 59(3): 1061-1072

Smoke exposure is often an inevitable side effect of open vegetation fires (both planned and wild) and is an important public health concern. The objective of this paper is to summarize state-of-the-art knowledge on health and environmental impacts of smoke from vegetation fires, to identify research gaps, and to provide needed information to researchers, land managers, policymakers, health care workers, and the general public. The main components of vegetation fire smoke and their characterizations are identified and evaluated. Concentrations, emission ratios, and emission factors of smoke components and the combined health and environmental effects of all hazardous smoke components from vegetation fire smoke exposure are summarized. Trends in risk assessment of vegetation fire smoke, limitations of current research, and future research needs are discussed.

Large commercial cattle feedlots are significant sources of particulate matter (PM) emissions. This research compared WindTrax and the flux-gradient technique in estimating emissions of PM with aerodynamic diameter 10) from cattle feedlots. Meteorological conditions were measured and PM10 concentrations were profiled vertically (i.e., 2.0 to 7.62 m) at a large commercial beef cattle feedlot in Kansas from May through September 2011. Results show that between the two methods evaluated, WindTrax was least sensitive to changes in heights and number of heights used in the emission estimation, with calculated PM10 emission rates varying by up to 18% only. On the other hand, PM10 emission rates produced by the flux-gradient technique varied by almost 56% when changing either heights and/or number of heights in emission calculation. Both methods were sensitive to height settings, with their respective PM10 emission rates higher when the lowest height setting (2.0 m) was included. Calculating PM10 emission rates with the 7.62-m height led to lower estimates for the flux-gradient technique but no significant change in estimates was observed for WindTrax. As demonstrated in this study, for the flux-gradient technique, settings for the lowest and highest heights were the most critical in emission estimation; exclusion of other heights in between showed only to 2% to 6% change in calculated PM10 emission rates. In general, the higher PM10 emission rates were obtained with the flux-gradient technique. However, eliminating the lowest height (2.0 m) in the calculation and, at the same time, using a specific set of formulations for the flux-gradient technique made its calculated PM10 emission rates slightly lower (but not significantly different) than those from WindTrax.

Storing grain in bulk storage units results in grain packing from overbearing pressure, which increases grain bulk density and storage unit capacity. This study compared pack factors of hard red winter (HRW) wheat in vertical storage bins using different methods: the existing packing model (WPACKING), the USDA Risk Management Agency (RMA) method, and the USDA Farm Service Agency Warehouse Licensing and Examination Division (FSA-W) method. Grain bins containing HRW wheat were measured in Kansas, Oklahoma, and Texas. Packing was measured in corrugated steel bins and reinforced concrete bins with diameters ranging from 4.6 to 31.9 m (15.0 to 104.6 ft) and equivalent level grain heights ranging from 4.1 to 41.6 m (13.4 to 136.6 ft). The predicted masses of compacted stored wheat based on WPACKING, RMA, and FSA-W were compared to the reported mass from scale tickets. Pack factors predicted by WPACKING ranged from 0.929 to 1.073 for steel bins and from 0.986 to 1.077 for concrete bins. Pack factors predicted by the RMA method ranged from 0.991 to 1.157 for steel bins and from 0.993 to 1.099 for concrete bins. Pack factors predicted by the FSA-W method ranged from 0.985 to 1.126 for steel bins and from 1.012 to 1.101 for concrete bins. The average absolute and median differences between the WPACKING-predicted mass and reported mass were 1.64% and -1.26%, respectively, for corrugated steel bins and 3.75% and 2.16%, respectively, for concrete bins. In most cases, WPACKING underpredicted the mass in corrugated steel bins and overpredicted the mass in concrete bins. Comparison of the RMA-predicted mass and reported mass showed an average absolute difference of 4.41% with a median difference of 1.91% for HRW wheat in steel bins and an average absolute difference of 3.25% with a median difference of 1.03% for concrete bins. For the FSA-W-predicted mass versus reported mass, the average absolute and median differences were 3.40% and 3.86%, respectively, for steel bins and 4.34% and 3.50%, respectively, for concrete bins. Most of the mass values were overpredicted by both the RMA and FSA-W methods. Some of the large differences observed for concrete bins can be attributed to the unique geometry of these bins and the difficulty in describing these bin shapes mathematically. Overall, compared to the reported mass, WPACKING predicted the mass of grain in the bins with less error than the current RMA and FSA-W methods. Some of the differences may be because the RMA and FSA-W methods do not include the effects of grain moisture content, bin wall type, and grain height on pack factors.

Off-road vehicle training can contribute to air quality degradation because of increased wind erosion as a result of soil disruption during high wind events. However, limited information exists regarding the impacts of off-road vehicle maneuvering on wind erosion potential of soils. This study was conducted to determine the effects of soil texture and intensity of training with off-road vehicles on fugitive dust emission potential due to wind erosion at military training installations. Multi-pass military vehicle trafficking experiments involving wheeled and tracked vehicles were conducted at three military training facilities (Fort Riley, Kansas; Fort Benning, Georgia; and Yakima Training Center, Washington) with different vegetative conditions and soil textures. The top 6 cm of soil was collected with minimum disturbance into trays and tested in a laboratory wind tunnel for dust emission potential. In wind tunnel testing, the amount of emitted dust was measured using a Grimm aerosol spectrometer. The dust emission potential due to wind erosion was significantly influenced by soil texture, vehicle type, and number of passes. For the light wheeled vehicle, total dust emissions (

Emissions data on air pollutants from large open-lot beef cattle feedlots are limited. This research was conducted to determine emissions of total suspended particulates (TSP) and particulate matter (PM10 and PM2.5) from a commercial beef cattle feedlot in Kansas (USA). Vertical particulate concentration profiles at the feedlot were measured using gravimetric samplers, and micrometeorological parameters were monitored with eddy covariance instrumentation during the nine 4- to 5-day intensive sampling campaigns from May 2010 through September 2011. Emission fluxes were determined from the measured concentration gradients and meteorological parameters using the flux-gradient technique. PM ratios based on calculated emission fluxes were 0.28 for PM2.5/PM10, 0.12 for PM2.5/TSP, and 0.24 for PM10/TSP, indicating that a large fraction of the PM emitted at the studied feedlot was in the coarse range of aerodynamic diameter, >10 μm. Median daily emission factors were 57, 21, and 11 kg 1000-head (hd)−1 d−1 for TSP (n = 20 days), PM10 (n = 19 days), and PM2.5 (n = 11 days), respectively. Cattle pen surface moisture contents of at least 20–30% significantly reduced both TSP and PM10 emissions, but moisture's effect on PM2.5 emissions was not established due to difficulty in measuring PM2.5 concentrations under low-PM conditions.

The proportion of reactive nitrogen in wet deposition attributable to ammonium (NH4+) has increased over the last three decades in the U.S. due to steadily increasing NH3 emissions and concomitant reductions in NOx emissions. The importance of examining NH3 emission sources and transport is amplified as the fraction of NH3 contributing to reactive nitrogen budget increases. Presented here is a study illustrating how the nitrogen stable isotopic composition of NH3 (δ15N–NH3) can be used to characterize the transport of NH3 emissions at the landscape-scale. To accomplish this, ambient NH3 was sampled across varying land use types (e.g. conventionally managed cornfield, tallgrass prairie, concentrated animal feeding operation (CAFO), dairy operation, urban setting) and analyzed for δ15N–NH3 values. Ambient δ15N–NH3 values at a conventionally managed cornfield were used in an isotope mixing model to make first order approximations of NH3 source contributions to ambient air over the cornfield. Results suggest that while volatilized fertilizer is a primary contributor to ambient NH3 after fertilizer application, during periods of low or no fertilization, vehicle NH3 emissions can be a substantial contributor to ambient NH3 over cornfields that are adjacent to roadways. These source approximations can aid in evaluating NH3 emission abatement techniques to local landscapes. Modeled NH3 deposition flux at a CAFO was found to contribute a considerable amount of nitrogen to the landscape and δ15N–NH3 values were used to trace the livestock source contributing to this flux. Ambient NH3 concentrations and δ15N–NH3 values were measured across an urban region and δ15N–NH3 values indicated primarily fossil fuel-based emissions and large spatial variations in NH3 concentrations.

Grain kernels are finite and discrete materials. Although flowing grain can behave like a continuum fluid at times, the discontinuous behavior exhibited by grain kernels cannot be simulated solely with conventional continuum-based computer modeling such as finite-element or finite-difference methods. The discrete element method (DEM) is a proven numerical method that can model discrete particles like grain kernels by tracking the motion of individual particles. DEM has been used extensively in the field of rock mechanics. Its application is gaining popularity in grain postharvest operations, but it has not been applied widely. This paper reviews existing applications of DEM in grain postharvest operations. Published literature that uses DEM to simulate postharvest processing is reviewed, as are applications in handling and processing of grain such as soybean, corn, wheat, rice, rapeseed, and the grain coproduct distillers dried grains with solubles (DDGS). Simulations of grain drying that involve particles in both free-flowing and confined-flow conditions are also included. Review of the existing literature indicates that DEM is a promising approach in the study of the behavior of deformable soft particulates such as grain and coproducts, and it could benefit from the development of improved particle models for these complex-shaped particles.

Literature on NH3 and H2S emissions from swine production facilities in North America was reviewed, and a meta-analysis was conducted on measured emissions data from swine houses and manure storage facilities as well as concentration data in the vicinity of swine production facilities. Results from more than 80 studies were compiled with results from the 11 swine sites in the National Air Emissions Monitoring Study (NAEMS). Data across studies were analyzed statistically using the MIXED procedures of SAS. The median emission rates from swine houses across various production stages and manure handling systems were 2.78 and 0.09 kg/yr per pig for NH3 and H2S, respectively. The median emission rates from swine storage facilities were 2.08 and 0.20 kg/yr per pig for NH3 and H2S, respectively. The size of swine farm that may trigger the need to report NH3 emissions under the Emergency Planning and Community Right-to-Know Act (EPCRA) is 3,410 pigs on the basis of the median NH3 emission rate (4.86 kg/yr per pig), but the threshold can be as low as 992 pigs on the basis of the 90th-percentile emission rates (16.71 kg/yr per pig). Swine hoop houses had significantly higher NH3 emission rate (14.80 kg/yr per pig) than other manure-handling systems (P < 0.01), whereas deep-pit houses had the highest H2S emission rate (16.03 kg/yr per pig, P = 0.03). Farrowing houses had the highest H2S emission rate (2.50 kg/yr per pig), followed by gestation houses, and finishing houses had the lowest H2S emission rate (P < 0.01). Regression models for NH3 and H2S emission rates were developed for finishing houses with deep pits, recharge pits, and lagoons. The NH3 emission rates increased with increasing air temperature, but effects of air temperature on H2S emission rates were not significant. The recharge interval of manure pits significantly affected H2S but not NH3 emission rates. The H2S emission rates were also influenced by the size of the operation. Although NH3 and H2S concentrations at the edge of swine houses or lagoons were often higher than corresponding acute or intermediate minimum risk levels (MRL), they decreased quickly to less than corresponding chronic or intermediate MRL as distances from emission sources increased. At the distances 30 to 1,185 m from emission sources, the average ambient concentrations for NH3 and H2S were 46 ± 46 µg/m(3) and 4.3 ± 8.6 µg/m(3) respectively.

Data on air emissions from open-lot beef cattle () feedlots are limited. This research was conducted to determine fluxes of particulate matter with an aerodynamic diameter ≤10 μm (PM) from a commercial beef cattle feedlot in Kansas using the flux-gradient technique, a widely used micrometeorological method for air emissions from open sources. Vertical PM concentration profiles and micrometeorological parameters were measured at the feedlot using tapered element oscillating microbalance PM samplers and eddy covariance instrumentations (i.e., sonic anemometer and infrared hygrometer), respectively, from May 2010 through September 2011, representing feedlot conditions with air temperatures ranging from -24 to 39°C. Calculated hourly PM fluxes varied diurnally and seasonally, ranging up to 272 mg m h, with an overall median of 36 mg m h. For warm conditions (air temperature of 21 ± 10°C), the highest hourly PM fluxes (range 116-146 mg m h) were observed during the early evening period, from 2000 to 2100 h. For cold conditions (air temperature of -2 ± 8°C), the highest PM fluxes (range 14-27 mg m h) were observed in the afternoon, from 1100 to 1500 h. Changes in the hourly trend of PM fluxes coincided with changes in friction velocity, air temperature, sensible heat flux, and surface roughness. The PM emission was also affected by the pen surface water content, where a water content of at least 20% (wet basis) would be sufficient to effectively reduce PM emissions from pens by as much as 60%.

Quantifying non-methane hydrocarbons (NMHC) from animal feeding operations (AFOs) is challenging due to the broad spectrum of compounds and the polar nature of the most abundant compounds. The purpose of this study was to determine the performance of commercial NMHC analyzers for measuring volatile organic compounds (VOCs) commonly emitted from AFOs. Three different NMHC analyzers were tested for response to laboratory generated VOCs, and two were tested in the field at a commercial poultry facility. The NMHC analyzers tested included gas chromatography/flame ionization detector (GC/FID), photoacoustic infrared (PA-IR) and photoionization detector (PID). The GC/FID NHHC analyzer was linear in response to nonpolar compounds, but detector response to polar oxygenated compounds were lower than expected due to poor peak shape on the column. The PA-IR NMHC instrument responded well to the calibration standard (propane), methanol, and acetone, but it performed poorly with larger alcohols and ketones and acetonitrile. The PA-IR response varied between compounds in similar compound classes. The PID responded poorly to many of the most abundant VOCs at AFOs, and it underreported alcohols by70%. In the field monitoring study, total NMHC concentrations were calculated from sum total of VOC determined using EPA Methods TO-15 and TO-17 with GC-MS compared to results from NMHC analyzers. NMHC GC/FID values were greater than the values calculated from the individual compound measurements. This indicated the presence of small hydrocarbons not measured with TO-15 or TO-17 such as propane. The PA-IR response was variable, but it was always lower than the GC/FID response. Results suggest that improved approaches are needed to accurately determine the VOC profile and NMHC emission rates from AFOs.

Prescribed rangeland burning in April is a long-standing practice in the Flint Hills region of eastern Kansas to maintain the tallgrass prairie ecosystem. The smoke plumes originating from these fires increases ambient PM2.5 concentrations and potentially contributes to ozone (O3) exceedances in downwind communities. Source apportionment research using Unmix modeling has been utilized to estimate contributions of Kansas rangeland burning to ambient PM2.5 concentrations. The objective of this study was to investigate the potential correlations between O3 and various sources of PM2.5 that are derived from receptor modeling, and then to specifically estimate contributions of Kansas rangeland burning to ambient O3 concentrations through regression analysis. Various daily meteorological data were used as predictor variables. Multiple regression models were developed for the eight-hour daily maximum O3 as well as the daily contributions of the five PM2.5 source categories that were derived from receptor modeling. Cross correlation was analyzed among residuals of the meteorological regression models for O3 and the daily contributions of the five PM2.5 source categories in order to identify the potential hidden correlation between O3 and PM2.5. The model including effects of meteorological variables and episodic contributions from fire and industrial emissions can explain up to 78% of O3 variability. For non-rainy days in April, the daily average contribution from prescribed rangeland burning to O3 was 1.8 ppb. On 3% of the days in April, prescribed rangeland burning contributed over 12.7 ppb to O3; and on 7% of the days in April, burning contributed more than 7.2 ppb to O3. When the intensive burning activities occur in days with high O3 background due to high solar radiation or O3 carryover from the previous day, the contributions from these episodic fire emissions could result in O3 exceedances of the National Ambient Air Quality Standards (NAAQS). The regression models developed in this study demonstrated that the most valuable predictors for O3 in the Flint Hills region include the O3 level on the previous day, total solar radiation, difference between daily maximum and minimum air temperature, and levels of episodic fire and industrial emissions. The long term goal is to establish an online O3 forecasting tool that can assist regulators and land managers in smoke management during the burning season so that the intensive burning activities can be planned to avoid forecasted high O3 days and thus prevent O3 exceedance.

The objective of this study was to conduct a systematic review of published literature on ammonia (NH3) and enteric methane (CH4) emissions from beef and dairy cattle operations to obtain statistically representative emission factors based on dietary intakes of nutrients or energy, and to identify major causes of emission variations. NH3 emissions from lagoon or other manure storage facilities were not included in this review. The NH3 and CH4 emission rates, expressed as a percentage losses of dietary nutrients or energy, demonstrated much less variation compared with emission rates expressed in g/animal/day. Air temperature and dietary crude protein (CP) content were identified as two major factors that can affect NH3 emission rates in addition to farm type. Feed digestibility and energy intake were identified as two major factors that can affect CH4 emission rates expressed as a percentage losses of dietary energy. Generally, increasing productivity and feed efficiency represented the greatest opportunity for mitigating NH3 or CH4 emissions per unit of livestock product. Expressing CH4 loss on a digestible energy basis rather than a gross energy intake basis can better represent the large variation among diets and the effects of varying dietary emission mitigation strategies.

Reverse dispersion modeling has been used to determine air emission fluxes from ground-level area sources, including open-lot beef cattle feedlots. This research compared Gaussian-based AERMOD, the preferred regulatory dispersion model of the US. Environmental Protection Agency (EPA), and WindTrax, a backward Lagrangian stochastic-based dispersion model, in determining PM10 emission rates for a large beef cattle feedlot in Kansas. The effect of the type of meteorological data was also evaluated. Meteorological conditions and PM10 concentrations at the feedlot were measured with micrometeorological/eddy covariance instrumentation and tapered element oscillating microbalance (TEOM) PM10 monitors, respectively, from May 2010 through September 2011. Using the measured meteorological conditions and assuming a unit emission flux (i.e., 1 microg/m2-sec), each model was used to calculate PM10 concentrations (referred to as unit-flux concentrations). PM10 emission fluxes were then back-calculated using the measured and calculated unit-flux PM10 concentrations. For AERMOD, results showed that the PM10 emission fluxes determined using the two different meteorological data sets evaluated (eddy covariance-derived and AERMET-generated) were basically the same. For WindTrax, the two meteorological data sets (sonic anemometer data set, a three-variable data set composed of wind parameters, surface roughness, and atmospheric stability) also produced basically the same PM10 emission fluxes. Back-calculated emission fluxes from AERMOD were 32 to 69% higher than those from WindTrax.This work compared the PM10 emission rates determined from a large commercial cattle feedlot in Kansas by reverse dispersion modeling using AERMOD and WindTrax. Emission fluxes derived from AERMOD were greater than those from WindTrax by mean factors of 1.3 to 1.6. Based on the high linearity observed between the two models, emission fluxes derived from one dispersion model for the purpose of simulating dispersion could be applied to the other model using appropriate conversion factors.

Emissions of particulate matter (PM) from animal feeding operations (AFOs) pose a potential threat to the health of humans and livestock. Current efforts to characterize PM emissions from AFOs generally examine variations in mass concentration and particle size distributions over time and space, but these methods do not provide information on the sources of the PM captured. Raman microscopy was employed as a non-destructive method to quantify the contributions of source materials to PM10 emitted from a large cattle feedlot. Raman spectra from potential source materials (dust from unpaved roads, manure from pen surface, and cattle feed) were compiled to create a spectral library. Multivariate statistical analysis methods were used to identify specific groups composing the source library spectra and to construct a linear discriminant function to identify the source of particles collected on PM10 sample filters. Cross validation of the model resulted in 99.76% correct classification of source spectra in the training group. Source characterization results from samples collected at the cattle feedlot over a two-day period indicate that manure from the cattle pen surface contributed an average of 78% of the total PM10 particles, and dust from unpaved roads accounted for an average of 19% with minor contributions from feed. Results of this work are promising and provide support for further investigation into an innovative method to identify agricultural PM10 sources accurately under different meteorological and management conditions.

Brass flakes and carbon-based particulates are effective obscurants in the infrared (IR) region of the electromagnetic spectrum; however, they are toxic and can cause respiratory problems and environmental concerns. There is a need to develop or identify nontoxic IR obscurants. This research was conducted to determine the potential of nanostructured particles as IR obscurants. Three commercial nanostructured particles were compared with two conventional particles and common obscurants. Experiments involved dispersing a known mass of particles into a particle chamber and measuring the IR transmission through the chamber with a Fourier transform infrared analyzer and the mass concentration with filter samplers. The size distribution of the aerosolized particles was also measured with an aerodynamic particle sizer spectrometer. From the measured data, the mean values of the mass extinction coefficient, σm, and volume extinction coefficient, σv, for the spectral bands of interest (i.e., 3–5 μm and 8–12 μm) we...

Open beef cattle feedlots emit various air pollutants, including particulate matter (PM) with equivalent aerodynamic diameter of 10 microm or less (PM10); however limited research has quantified PM10 emission rates from feedlots. This research was conducted to determine emission rates of PM10 from large cattle feedlots in Kansas. Concentrations of PM10 at the downwind and upwind edges of two large cattle feedlots (KS1 and KS2) in Kansas were measured with tapered element oscillating microbalance (TEOM) PM10 monitors from January 2007 to December 2008. Weather conditions at the feedlots were also monitored. From measured PM10 concentrations and weather conditions, PM10 emission rates were determined using reverse modeling with the American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model (AERMOD). The two feedlots differed significantly in median PM10 emission flux (1.60 g/m2-day for KS1 vs. 1.10 g/m2-day for KS2) but not in PM10 emission factor (27 kg/1000 head-day for KS1 and 30 kg/1000 head-day KS2). These emission factors were smaller than published U.S. Environmental Protection Agency (EPA) emission factor for cattle feedlots.

Vegetative barriers have the potential to mitigate particulate matter (PM) from open dust sources, including unpaved and paved roads, exposed storage piles, and agricultural sources; however, data on their effectiveness in capturing PM are limited. This study was conducted to predict the airflow and particle collection efficiency of vegetative barriers. The applicability of computational fluid dynamics (CFD) in modeling airflow around and through porous barriers was first evaluated by simulating airflow passing a porous fence (1.2 m high × 0.01 m thick, 50% porosity) using standard and realizable k -e turbulence models in FLUENT. Predicted air velocities compared favorably with available experimental data. The CFD model was then applied to simulate airflow and particle collection by a row of trees (2.2 m high × 1.6 m wide) with characteristics similar to those of hawthorn trees. The Eulerian-Eulerian model was used to predict particle transport and collection by the tree elements. Predicted partic...

Unwanted grain commingling impedes new quality-based grain handling systems and has proven to be an expensive and time-consuming issue to study experimentally. Experimentally validated models may reduce the time and expense of studying grain commingling while providing additional insight into details of the particle flow. In this study, grain commingling in a pilot-scale bucket elevator boot was first modeled in three-dimensional (3-D) discrete element method (DEM) simulations. Experiments on the pilot-scale boot were performed using red-dyed and clear (uncolored) soybeans to validate the 3-D DEM model. Predicted results from the 3-D boot model generally followed the experimental data but tended to underpredict commingling early in the process. To reduce computational time, quasi-two-dimensional (quasi-2-D) DEM simulations were also evaluated. Comparison of predicted average commingling of five quasi-2-D boot models with reduced control volumes (i.e., with boot widths from four to seven times the mean particle diameter) led to the selection of the quasi-2-D model with a boot width of 5.6 times the mean particle diameter (i.e., 5.6d) to reduce computational time. In addition, the 3-D and quasi-2-D (5.6d) models were refined by accounting for the initial surge of particles at the beginning of each test and correcting for the effective dynamic gap between the bucket cups and the boot wall. The quasi-2-D (5.6d) models reduced simulation run time by approximately 70% compared to the 3-D model of the pilot-scale boot. Results of this study can be used to accurately predict commingling levels and improve grain handling, which can help farmers and grain handlers reduce costs and maintain grain purity during transport and export of grain.