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HighlightsWheat flour cohesion was modeled using the Johnson-Kendall-Roberts (JKR) contact model.The size-based separation was highly influenced by particle size, particle roughness, cohesion, and sieve opening size.Sieve blinding happened at 15.25 and 10.32 s of sieving for hard red winter (HRW) and soft red winter (SRW) wheat flour particles, respectively.Abstract. Sifting or size-based separation of flour particles is an important operation in the wheat milling process. During the separation process, the flour particles often behave as imperfect solids with discontinuous flow and tend to form agglomerates due to interparticle cohesion. Interparticle cohesion in flours is highly dependent on the particle physical and chemical parameters and influences the sieving process. This study presents the development of a discrete element method (DEM) model to predict the size-based separation of wheat flours at 10% and 14% moisture contents (wet basis). DEM models of the size-based separation process were developed using the Hertz-Mindlin contact model. To account for the interparticle cohesion, the Johnson-Kendall-Roberts (JKR) model was coupled with the contact model. The size-based separation of hard red winter (HRW) and soft red winter (SRW) wheat flours was simulated and then validated using lab-scale experiments. Both the modeling and experimental approaches indicated that the percent particle separation was higher in the sieves with larger openings. Particle size, roughness, and cohesion affected the size-based separation in sieves with smaller openings. The model simulation results for the percent mass retained on the screens and the sieve blinding time were comparable with the experimental results. The standard error of prediction (SEP) ranged from 0.13 to 8.27, which indicates that this approach will be useful to predict the size-based separation of cohesive fine particles. The developed model will also be useful to estimate the sieve blinding time during sifting processes. Keywords: Cohesion, Johnson-Kendall-Roberts model, Sifting, Wheat milling.

HighlightsAn egg-collecting robot embedded with deep-learning-based computer vision algorithms was constructed.The retrained deep-learning detector achieved >93% performance for detecting and locating eggs in images.The kernel sizes of 65 × 65 pixels for erosion and dilation in image processing assisted in extracting geometry features of eggs with the least remaining noises.The robot with soft grouting sponge on the gripper had 92% to 94% success in picking white and brown eggs.Abstract. Manual collection of floor eggs in cage-free hen housing systems is time-consuming and laborious. The objectives of this study were to (1) develop a robot to automatically collect floor eggs and (2) optimize the performance of recognizing and picking eggs with the robot. The robot consisted of a deep-learning-based egg detector, a robot arm, a two-finger gripper, and a hand-mounted camera. The deep-learning model, You Only Look Once (YOLO) V3, was embedded in the vision system to detect and locate eggs on a simulated litter floor in real-time. Image processing algorithms (e.g., cropping, erosion, etc.) were implemented for the detection and provided the robot with centroid coordinates, orientation, and axis lengths of the detected eggs, so that the gripper could be manipulated with an appropriate angle and opening width to grasp the detected eggs. For optimization, the YOLO V3 model was retrained with a dataset of floor eggs and achieved >93% performance in detecting and locating eggs. The kernel size of 65 × 65 pixels for erosion and dilation in image processing assisted in extracting the geometry features of eggs with the least remaining noises. Among the tested materials, soft grouting sponge attached to the gripper had the highest success rates for egg picking. The robot achieved 92% to 94% success in picking white and brown eggs. In sum, the developed egg-collecting robot can be relied on for picking floor eggs to assist in precision management of cage-free hen housing systems. Keywords: Floor egg, Image processing, Laying hen, Robot arm, Soft gripper, YOLO V3.

HighlightsOpen-lot beef cattle feedyards are a source of greenhouse gas emissions.Pen surface methane emissions were quantified during the cool and warm seasons.Methane was generated in the lower anaerobic layers of the manure pack.Methane emissions decreased after rainfall due to methane oxidation or blocking of pore space.Pen surface methane emissions accounted for <1% of overall feedyard GHG as CO2eq.Abstract. Texas is one of the top beef-producing states, where annually more than five million beef cattle are finished in large feedyards on earthen-surfaced pens. Manure deposited on open-lot pen surfaces can contribute to greenhouse gas (GHG) emissions such as methane (CH4). Two week-long sampling campaigns were conducted in April (cool season) and August (warm season) to quantify CH4 emissions from the feedyard pen surface. Emissions were monitored before and after 12.7 mm simulated rainfall events. Temporal and spatial variabilities in emissions were quantified using automated recirculating flux chambers, a multiplexer system, and a real-time CH4 analyzer. During the cool season, mean CH4 flux was 1.09 (SD ±2.39) and 0.12 (±0.25) g animal-1 d-1 before and after rainfall, respectively. During the warm season, mean CH4 flux was 0.65 (±1.01) and 0.26 (±0.44) g animal-1 d-1 before and after rainfall, respectively. This suggested that CH4 was produced in the lower, anaerobic layer of the manure pack and CH4 emissions were inhibited following rainfall, most likely due to microbial oxidation of CH4 in the upper layers through methanotrophy or from slowing of diffusion by blocking the manure pore space. The overall mean pen surface CH4 flux was 0.53 g animal-1 d-1. This flux accounted for a small percentage (<1%) of the overall estimated feedyard GHG emissions expressed as CO2eq. Thus, efforts to mitigate GHG from open-lot beef cattle feedyards in the Texas Panhandle should focus on sources with higher percentages of overall GHG, such as enteric methane, pen surface nitrous oxide, and nitrous oxide from fertilized cropland. Keywords: Beef cattle, Flux chamber, Greenhouse gas, Manure, Methane, Rainfall.

HighlightsA prototype pneumatic machine used to control the Colorado potato beetle (CPB) had no effect on potato plant growth.Yields in pneumatic treatment plots were comparable to those of control plots treated with a biological insecticide.Pneumatic control of the CPB could be an alternative to reduce reliance on chemical insecticides in potato fields.Abstract. The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the major insect pest of potato plants. Currently, the most effective method for controlling the CPB is to apply chemical insecticides throughout its lifecycle. However, the CPB has the ability to resist most chemical insecticides. Control of this insect pest has therefore become extremely difficult, prompting researchers to explore effective alternatives. The use of pneumatic methods to control the CPB is a promising alternative to chemical means. The objective of this study was to develop an effective pneumatic control method for the CPB to reduce the reliance on chemical insecticides in potato fields. In this context, a prototype pneumatic machine was designed and built. The prototype uses positive air pressure to dislodge CPBs from potato foliage, deposit them on the ground between the rows, and crush them. The effects of three airflow velocities (45, 50, and 55 m s-1) and two tractor travel speeds (5 and 6 km h-1) on CPB control, plant growth, and tuber yield were investigated in potato plots. Overall, the results showed no significant differences in yield between treatments (p = 0.3268), indicating that the yield of potato plants treated with the prototype was comparable to that of plants treated with a biological insecticide (Entrust). In addition, the prototype did not have any negative effects on plant growth. This suggests that the prototype could be safely and efficiently used in potato fields to control the CPB. The success of this innovative control method could greatly contribute to reducing the use of chemical insecticides to control the CPB. Keywords: Airflow velocity, Leptinotarsa decemlineata (Say), Pneumatic control, Potato, Travel speed.

HighlightsForage rape crop could effectively alleviate the lack of green forage for livestock in winter.With the growth of forage rape crop, stem lignification was exacerbated and its palatability degenerated.The relationship between particle length and palatability was explored in a cattle feeding experiment.Optimal working parameters of the chopping device were obtained for harvesting the crop in different stages.Abstract. Forage rape crop, which uses the immature plant leaf and stem of a hybrid rape crop (Brassica napus L.) with low erucic acid and glucosinolate to feed livestock, is an innovative fresh-fed feed material with the advantages of high yield, low cost, rich nutrients, and vigorous growth in winter. In this work, a systematic study was carried out on the relationships among the characteristics of forage rape crop stems, chopping device parameters of the harvester, feeding performance, and chopped particle length (PL) in different growth stages. The results of the stem characteristics tests indicated that stem lignification occurred and increased with growth of the crop from the bolting stage to the silique stage, leading to degeneration of its palatability. The cattle feeding experiment showed that when the bolting rape crop was used, the average feed intake of the cattle fed the chopped rape crop increased by 33.35%, compared to feeding the whole crop without chopping, while the average feeding time decreased by 35.44%. Further experiments on the effects of PL after chopping on feeding performance in different growth stages showed that the optimal PL values in the bolting, flowering, and silique stages were 80, 60, and 30 mm, respectively. Finally, the corresponding cutterhead rotational speeds of the chopping device were calculated as 450, 510, and 1200 r min-1, respectively. This study provides a reference for the development and application of harvesting equipment for forage rape crop. Keywords: Agricultural mechanization, Cattle feeding, Forage palatability, Harvester, Parameter matching.

HighlightsThe efficacy of EWNS to disinfect surfaces was assessed at a bacterial concentration similar to pig barns.Liquid pH, liquid conductivity, and applied voltage were found to directly affect the efficacy of EWNS.The efficacy increased as liquid flow rate and distance between needle tip and counter electrode decreased.An E. coli reduction of 3.0 log was achieved on a stainless-steel surface after 15 min exposure to EWNS.Abstract. Several studies have shown the potential of engineered water nanostructures (EWNS) generated using a capillary electrospray system to inactivate foodborne bacteria; however, there is a lack of data on EWNS performance in inactivating microbes in livestock facilities. Thus, this laboratory-scale study investigated the effects of operating conditions on the efficacy of EWNS in inactivating Escherichia coli (E. coli) on coupons made of stainless steel, a common surface material in pig barns, at a bacterial concentration similar to levels found on pig barn surfaces. The electrospray module was composed of a capillary needle that was connected to a high-voltage power supply. The efficacy of the technology in inactivating E. coli was assessed with various operating parameters (i.e., applied voltage, distance between needle tip and counter electrode, and liquid flow rate, pH, and conductivity). The efficacy of the EWNS was found to be directly related to the liquid pH, liquid conductivity, and applied voltage, but inversely related to the liquid flow rate and distance between the needle tip and counter electrode. An E. coli reduction of 3.0 log was obtained after 15 min exposure to EWNS under the following operating conditions: liquid flow rate of 1 µL min-1, pH of 12, liquid conductivity of 14.72 mS cm-1, 2 cm distance between the needle tip and counter electrode, and -7.6 kV applied voltage. The results of this study can serve as an initial basis for the application of EWNS on surfaces in a real barn environment, where the presence of other factors, such as gases, dust, and other organic matter and microbial species, must be taken into account. Keywords: Electrospray, Engineered water nanostructures, E. coli, Stainless-steel surface, Surface decontamination.

HighlightsFTC-4 treated brown rice showed better protein digestibility.BR-AAS was used to evaluate the nutritive value of released free amino acids.G24P treated brown rice is recommended to supplement amino acid intake in a daily diet.Abstract. The objective of this study was to evaluate the in vitro protein digestibility of brown rice (BR) after high-pressure (HP), freeze-thaw cycle (FTC), and germination-parboiling (GP) treatments. Four-cycle freeze-thaw (FTC-4) treatment enhanced digestibility, and all treated BR released more essential and total amino acids after digestion. To evaluate the nutritive value of free amino acids released after digestion (on the premise of the same intake of BR products), a BR amino acid score (BR-AAS) was used, based on the patterns of protein digestibility-corrected amino acid scores with modifications. Results suggested that BR treated with 24 h of germination followed by 10 min of parboiling (G24P) was a better choice for supplementing amino acid intake in a daily diet. All treatments resulted in decreased protein solubility, which was negatively correlated with surface hydrophobicity and disulfide bond contents. The HP, FTC, and GP treatments affected certain protein properties, which was helpful in explaining the differences in protein digestibility of BR. Changes in other constituents were considered important with respect to the treatment influence on protein digestibility. Keywords: Brown rice, Freeze-thaw cycles, Germination-parboiling, High-pressure, Protein in vitro digestibility.

HighlightsMechanical work can be generated from fertilizer via pressure-retarded osmosis.Laboratory tests show up to 5 Wh of energy recovered per kg of fertilizer.Tradeoffs between energy recovery and power generation are demonstrated.Maintaining power above 5 W m-2 is reasonable given current membrane technology.Abstract. Large amounts of energy are released when concentrated fertilizers are diluted in water. In this study, we demonstrate the use of fertilizer to generate useful mechanical work via pressure-retarded osmosis (PRO). A number of common single solutes and fertilizer blends were analyzed using both experimental and numerical methods. Laboratory test trials showed energy recovery of up to 5 Wh kg-1 of fertilizer and power of up 6 W m-2 of membrane area given commercial cellulose triacetate membranes. A drop in power was demonstrated throughout the fertilizer PRO batch process, and the resulting tradeoffs between energy recovery and power density are discussed. Simulation results suggest that high-performance membranes can be used to maintain elevated power above 5 W m-2 throughout the batch process, while recovering approximately 5 Wh kg-1. The loss of valuable fertilizer via leakage to the feed stream was found to be less than 1% of the initial fertilizer mass, suggesting that this non-ideal dynamic can be reasonably minimized. Implications at the food-energy-water nexus are discussed. Keywords: Fertilizer osmosis, Forward osmosis, Fertilizer energy, Food-energy-water nexus.

HighlightsConvective currents led to hydraulic flux and transport of P between bottom and surface waters of the littoral zone.Hydraulic flux was primarily into the bottom of the cove and out of the cove along the surface.Eutrophic littoral areas are a significant source of P to the photic zone of reservoirs, supporting algal growth.Abstract. Eutrophication of surface waters is defined by excessive algal growth, with consequences for drinking water treatment. The sources of phosphorus (P) in southern U.S. reservoirs that fuel peak algal productivity in late summer are still not fully understood. One potential source is reservoir littoral zones, which have been described as the most productive zone of a waterbody. A shallow cove named Granny Hollow in Beaver Lake, northwest Arkansas, was selected as an isolated and semi-controlled location to measure and model sources of P and its transport in a littoral area for the month of July 2018. Hydraulic and P fluxes between the reservoir and littoral area were quantified through field measurements and a 3D lake model. In quantifying hydraulic flux for the month of July, the model indicated that water tended to move into the cove along the bottom and out along the top, with a net hydraulic flux out of the cove of -723,000 m3. Peak surface velocity in the cove averaged 2.09 cm s-1 for the month of July, while peak bottom velocity was 1.29 cm s-1. Diurnally, water movement switched directions, moving out of the cove along the surface during differential heating and into the cove along the surface during differential cooling due to thermoconvective flow. During differential heating, the water velocity and hydraulic flux to the main reservoir channel along the surface of the cove were greater than the velocity and flux in the opposite direction during differential cooling. The sources of P within the cove during July included P released from bottom sediments within the cove and littoral zone and transport of P from the reservoir channel to the cove. Transport of P from the main reservoir into the cove was a result of thermoconvective flow. During differential heating, bottom waters from the main reservoir channel were transported to the surface within the littoral zone by thermoconvective currents flowing upslope from deeper to shallower waters. This resulted in P exchange between the reservoir and littoral area and is significant because it represents movement of P from the bottom of the reservoir upward into the photic zone, where it can be used for algal productivity. During July 2018, it was estimated that 13.3 kg of P were transported from the bottom of the cove to the surface by convective currents and subsequently out of the cove. This study shows that eutrophic coves represent a significant source of P to the reservoir and more importantly to the photic zone, supporting algal growth. Keywords: 3D reservoir model, Eutrophication, Internal loading, Thermoconvective flow.

HighlightsAn integrated GPS/INS/VNS navigation system was developed to improve navigation accuracy.An adaptive federal Kalman filter with information distribution factors was used to fuse navigation information.Detection of seedling row lines was achieved based on subregional feature points clustering.A modified rice transplanter was developed as an experimental platform for automatic navigation.Abstract. In this article, an integrated global positioning system (GPS), inertial navigation system (INS), and visual navigation system (VNS) navigation method based on an adaptive federal Kalman filter (KF) is presented to improve positioning accuracy for a rice transplanter operating in a paddy field. The proposed method used GPS/VNS to aid the INS and reduce the influence of the accumulated error of the INS on navigation accuracy. An adaptive federal KF algorithm was designed to fuse navigation information from different sensors. The information distribution factor of each local filter was obtained adaptively on the basis of its own error covariance matrix. Computer simulation and transplanter tests were conducted to verify the proposed method. Results showed that the proposed method provided accurate and reliable navigation information outputs and achieved better navigation performance compared with single GPS navigation and an integrated method based on a conventional federal KF. Keywords: Federal Kalman filter, GPS/INS/VNS, Information distribution factor, Information fusion, Integrated navigation.