Journal of the ASABE最新文献

{"title":"Simplified Modeling of High-Solids Anaerobic Digestion of Dairy Manure in a Pilot-Scale Stirred Tank Anaerobic Digester","authors":"I. D. Kariyama, Weixiang Li, Shaoqi Yu, Long Chen, R. Qi, Hao Zhang, Xiaxia Li, Xin Deng, Jiansen Lin, Binxin Wu","doi":"10.13031/ja.15203","DOIUrl":"https://doi.org/10.13031/ja.15203","url":null,"abstract":"Highlights HSAD is a cost-effective approach for managing high-solids manure. Batch digestion of HSAD at a low inoculum ratio is unsuitable. Mixing once a day was enough to maintain a stable digestion process. The stoichiometric method with an appropriate biodegradability factor provided perfect prediction. Simplified biokinetics can predict methane productivity at steady-state conditions. Abstract. Anaerobic digestion (AD) is considered one of the most effective methods of managing dairy manure. To effectively and economically treat the huge volumes of manure produced by commercial dairy farms, high-solids anaerobic digestion (HSAD) is to be encouraged. In this manuscript, batch and semi-continuous anaerobic digestion experiments of dairy manure with a high volatile solid (VS) content were conducted in a pilot-scale stirred digester with an effective volume of 1.63 m3, operated under mesophilic temperature conditions. Three intermittent mixing treatments (50, 100, and 150 rpm) were mixed once a day during feeding with a constant mixing duration of 5 minutes, including a non-mixed experiment, operating at a 30-day hydraulic retention time. The objectives were to determine an optimum mixing intensity to enhance HSAD efficiency and economy and to apply simplified models to model the digestion process. The simplified kinetic models were modified to accurately predict methane growth, yield, and production rates. The modified Gompertz growth model predicted the methane growth at the batch experiment perfectly. The first-order kinetic model predictions of the biodegradability factor, the specific methane yield, and the specific methane production rate were consistent with the batch experimental results. The stoichiometric method and the Karim model were modified to accurately model the effect of mixing intensity on the methane yield and the specific methane production rate. Three linear equations were successfully developed to predict the methane production rate. Optimized mixing intensity and organic loading rate are critical for high methane production rates. This study contributes to the ongoing research to improve the efficiency of HSAD. Keywords: Dairy manure, High-solids anaerobic digestion, Methane productivity, Mixing intensity.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90325834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized Chassis Stability Relative to Dynamic Terrain Profiles in a Self-Propelled Sprayer Multibody Dynamics Model","authors":"Bailey Adams, M. Darr, Aditya Shah","doi":"10.13031/ja.15230","DOIUrl":"https://doi.org/10.13031/ja.15230","url":null,"abstract":"Highlights This study presented a new optimization methodology using a prismatic joint with high stiffness and damping. The virtual suspension model contained the main bodies, an optimization subsystem, and a free-floating cylinder. Under aggressive terrain, an optimized chassis platform resulted in a 19.5% increase in boom height stability. Abstract. Multibody dynamics (MBD) models are continuing to be valuable for engineering design and product development, especially regarding subsystem optimization. Most MBD optimization processes begin with a sensitivity analysis of treatment factors and levels to understand how uncertainty in model inputs can be attributed to different sources of uncertainty within model outputs; however, this study developed a new MBD methodology to automatically determine the optimized dynamic chassis suspension responses on each corner of the vehicle from a single simulation for a self-propelled sprayer model as the chosen application use-case. This technique leveraged a prismatic joint (with a high spring stiffness and damping coefficient) connected between the chassis mainframe and the simplified optimization tire to create a distance constraint that held the chassis body at a near-consistent height above the ground. Then the solver optimized the response of the chassis suspension system to maintain a stable chassis platform relative to the terrain beneath it as the vehicle traversed across dynamic terrain conditions. This optimization response was also accomplished by replacing the baseline chassis suspension components with a free-floating cylinder, which permitted the unrestricted, optimized motion needed to keep the chassis body at a near-level position with respect to the roll and pitch profiles of the terrain. For a simulation with an aggressive terrain configuration, the analysis showed that an optimized suspension system resulted in a 46% decrease in operator comfort and a 19.5% increase in overall boom height stability as the boom height control system better maintained a dynamic position closer to the specified target height. Keywords: Boom height, Chassis suspension, Multibody dynamics (MBD), Optimization, Prismatic joint, Simulation, Terrain.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89617301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts on Teamwork Performance for an Engineering Capstone in Emergency Remote Teaching","authors":"Brandi Brown, Miguel Fudolig, T. Brown-Brandl, Deepak R. Keshwani","doi":"10.13031/ja.15265","DOIUrl":"https://doi.org/10.13031/ja.15265","url":null,"abstract":"Highlights Teamwork data from engineering capstone courses were analyzed to detect impacts of emergency remote teaching. The Comprehensive Assessment for Team-Member Effectiveness (CATME) data was analyzed via statistical modeling. Qualitative data attained from student responses were analyzed for patterns. Students found the lack of team camaraderie even more challenging than limitations on testing designs. This study offers avenues for developing engineering students’ teamwork skills in remote settings. Abstract. The onset of the global pandemic forced universities to rapidly shift to emergency remote teaching (ERT), which could cause even more perturbations for engineering courses with a hands-on, project-oriented focus. Thus, the purpose of this project was to gain a data-driven appreciation of how teamwork performance was impacted for engineering students in this environment and recommend focus areas for instructional designers. The Comprehensive Assessment for Team-Member Effectiveness (CATME) tool was used to assess different aspects of teamwork performance for 108 students in an undergraduate engineering capstone course during an in-person course offered in 2019-2020 (pre-pandemic) and an ERT course offered in 2020-2021 at a major Midwestern university. The classes were divided into teams for their capstone projects using the CATME Team-Maker tool. Students were asked to rate their teammates at the beginning, middle, and end of the course across five CATME dimensions: (1) Contribution to Team’s Work, (2) Interacting with Teammates, (3) Keeping the Team on Track, (4) Expecting Quality, and (5) Having Relevant Knowledge, Skills, and Abilities (KSAs). Statistical modeling was implemented to decipher how ratings differed throughout the year in each course as well as to identify specific CATME areas that varied between the in-person and ERT courses. A qualitative assessment was also implemented for the ERT course based on student responses to a prompt that asked them to comment on how the pandemic impacted their personal and team performance. Results revealed that engineering students showed a significant reduction in three categories in the ERT course compared to in-person: Contributing to Team’s Work, Expecting Quality, and Having Relevant KSAs. Interestingly, these three categories deal largely with student motivation toward team efforts, which was echoed in the qualitative assessment. The majority of alarming comments made by students were regarding not being able to build camaraderie with their teammates in the ERT environment. It was surprising to find that engineering students found this lack of team camaraderie even more challenging than the limitations on testing their designs. Thus, more data-driven analyses are necessary to examine which methods and technologies are ideal for teleworking project-based courses in terms of facilitating team bonding, helping teams brainstorm, and fostering more en","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88154606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Wood Chips and Agricultural Residues as Denitrifying Bioreactor Feedstocks for Use in the Canadian Prairies","authors":"J. Kohn, Gregory S. Piorkowski, Nicole E. Seitz Vermeer, Janelle F. Villeneuve","doi":"10.13031/ja.15412","DOIUrl":"https://doi.org/10.13031/ja.15412","url":null,"abstract":"Highlights Performance of denitrifying bioreactors in Alberta was evaluated. Barley straw was more effective in reducing nitrate compared to wood chips. Hydraulic retention time, feedstock, and season are the primary factors affecting nitrate removal. Abstract. This study evaluated the performance of pilot-scale denitrifying bioreactors (LWD: 6 × 0.6 × 1m) filled with different carbon substrates, including barley straw, hemp straw, and woodchips, for removing dissolved nitrogen from simulated subsurface drainage at two representative geographic locations in Alberta. In this study, the bioreactors were tested under varying hydraulic retention times (4, 8, and 12 h) in the spring, summer, and fall of one year. Tracer studies were conducted to evaluate flow and dispersion characteristics. The mean of nitrate removal efficiency ranged from 19% to 87% during the spring, 44% to 95% during the summer, and 21% to 68% during the fall. We found that barley straw was more effective in reducing nitrate (45% to 95%) compared to wood chips (19% to 54%). This study is the first testing of the effect of different biomass types and hydraulic residence times on bioreactor performance in the Canadian prairies (Alberta) and will allow agricultural producers and regulators to assess the suitability of these systems within the region. Keywords: Bioreactor, Denitrification, Water quality, Wood chips, Agricultural residues, Subsurface Drainage.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91144126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Denitrifying Bioreactor In Situ Woodchip Bulk Density","authors":"L. Christianson, R. Christianson, C. Díaz-García, G. Johnson, B. Maxwell, R. Cooke, N. Wickramarathne, L. Gentry","doi":"10.13031/ja.15364","DOIUrl":"https://doi.org/10.13031/ja.15364","url":null,"abstract":"Highlights The bulk density of woodchips in denitrifying bioreactors in the field is unknown. In situ bulk density estimation methods were developed for use during construction or excavation. Dry bulk densities of aged woodchips at bioreactor bottoms were lower than previous literature values. Moisture and particle size and density explained some, but not all, of the variation in in situ bulk densities. Abstract. Woodchip bulk density in a denitrifying bioreactor governs system hydraulics, but this prime physical attribute has never been estimated in situ. The objectives were twofold: (1) to establish estimates of in situ woodchip bulk density at bioreactors in the field, and (2) evaluate causal factors for and resulting impacts of these estimates. Proof-of-concept bulk density methods were developed at a pilot-scale bioreactor using three ways to estimate volume: surveying the excavated area, pumping the excavation full through a flow meter, and using iPhone Light Detection and Ranging (LiDAR). These methods were then further tested at two new and three old full-size bioreactors. Additional ex situ (off-site) testing with the associated woodchips included analysis of bulk density along a moisture gradient and particle size, particle density, wood composition, and hydraulic property testing. In situ dry bulk densities based on the entire volume of the new bioreactors (206-224 kg/m3) were similar to values from previous lab-scale studies. In situ estimates for woodchips at the bottom of aged bioreactors (22-mo. to 6-y) were unexpectedly low (120-166 kg/m3), given that these woodchips would presumably be the most compacted. These low moisture-content corrected dry bulk densities were influenced by high moisture contents in situ (>70% wet basis). The impacts of particle size and particle density on bulk density were somewhat mixed across the dataset, but in general, smaller woodchips had higher dry bulk densities than larger, and several woodchips sourced from the bottom of bioreactors had low particle densities. Although dry bulk densities in the zone of flow in bioreactors in the field were shown to be relatively low, the resulting permeability coefficients under those packing conditions did not differ from those of the original woodchips. The LiDAR-based volume estimation method was the most practical for large-scale, full-size evaluations and allowed high precision with small features (e.g., vertical reactor edges, drainage fittings). Keywords: Compaction, Cone penetrometer, Drainable porosity, LiDAR, Moisture content, Survey.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91166711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Non-Thermal Plasma Alfalfa Seed Vigor Enhancement Device and Study of Treatment Effect","authors":"Yunting Hui, Yangyang Liao, Sibiao Li, Changyong Shao, Decheng Wang, Yong You","doi":"10.13031/ja.15309","DOIUrl":"https://doi.org/10.13031/ja.15309","url":null,"abstract":"Highlights An effective seed treatment method is provided. Three generations of field growth trials were conducted. We Investigated the effects of low-temperature plasma treatment on the biological characters and yield components. Abstract. An atmospheric pressure, low-temperature dielectric barrier discharge (DBD) plasma seed treatment device was developed for plasma seed treatment. The device worked continuously on alfalfa seeds and evenly distributed the seeds in a plasma discharge range. The processing time, voltage amplitude, and frequency were adjustable. The device was used to study the effect of DBD plasma treatment at different voltages and times on alfalfa seed germination using untreated alfalfa seeds as the control (CK). The results showed that the DBD plasma treatment of alfalfa seeds promoted seed germination and seedling growth, and the optimal discharge conditions were a discharge voltage of 11 kV and a discharge time of 40 s. Compared with CK, the germination potential and germination rate increased by 12.49% and 18.08%, respectively. After treatment using the optimal discharge time, the germination potential, germination rate, dry weight, and seedling height increased by 9.9%, 16.1%, 15%, and 32.9%, respectively, compared with CK. The Scanning Electron Microscope images of the seed epidermis treated with 11 kV and 40 s plasma showed that the surface of alfalfa seeds was etched. Different doses of discharge radiation had different effects on physiological processes in seeds, and their sensitivity to plasma discharge was different. In a certain range, the germination rate, germination potential, fresh weight, dry weight, root length, and seedling height of alfalfa seeds improved to different degrees under different discharge voltages and times. Plasma has a good application prospect for improving the growth of alfalfa seeds. Keywords: Alfalfa, Dielectric barrier discharge plasma, Germination, Seed treatment device, Seedling growth.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"120 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77419558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Air-Pinch PWM Valve to Regulate Flow Rate of Hollow-Cone Nozzles for Variable-Rate Sprayers","authors":"Javier Campos, Heping Zhu, Hongyoung Jeon, Ramón Salcedo, Erdal Ozkan, Carla Roman, Emilio Gil","doi":"10.13031/ja.15601","DOIUrl":"https://doi.org/10.13031/ja.15601","url":null,"abstract":"Highlights Air-pinch PWM valve was investigated as an alternative to electric PWM valves to manipulate hollow-cone nozzles. Air-pinch and electric PWM valves performed comparable accuracy in flow rate modulations. Droplet sizes from hollow-cone nozzles with both PWM valves were comparable across DUCs ranging from 20% to 100%. Air-pinch PWM valve had great potential of use due to its capacity to isolate the internal parts of the valve from chemicals. Abstract. Electric pulse width modulation (PWM) solenoid valves are commonly used to regulate nozzle flow rates to achieve precision variable-rate spray applications. However, some pesticide formulations, such as wettable powders and adhesive additives, can potentially cause a malfunction such that the valve cannot completely shut off during flow rate modulation if spray lines are not cleaned thoroughly after spray applications. An air-pinch PWM valve was evaluated as a potential alternative to conventional PWM valves to modulate the flow rates of hollow-cone nozzles used on air-assisted orchard sprayers. With the air-pinch valve, spray mixtures only passed through a flexible tube to avoid chemicals directly contacting the moving components inside the valve chamber. The flow rate modulation was performed by pinching and releasing the tube back and forth with air-pilot PWM actions. Evaluations included the flow rate modulation capability along with droplet size distributions from three disc-core hollow-cone nozzles coupled with the PWM pinch valve and compared with a conventional electric PWM valve. Both air-pinch and electric PWM valves performed comparably in the flow rate modulation accuracy and droplet size distribution for hollow-cone nozzles operated at 414 and 827 kPa pressures across the duty cycles (DUCs) ranging from 10% to 100%, except for the air-pinch valve that could not activate at 10% DUC. The flow rates of nozzles modulated with both PWM valves at all DUCs were 5.3% greater on average than the target flow rates, while the flow rates were similar at 90% and 100% DUCs. Droplet size classifications based on ASABE Standard S-572.3 were generally consistent across DUCs ranging from 20% to 100% for the same nozzle and pressure with the air-pinch PWM valve and from 10% to 100% with the conventional electric PWM valve. The consistency of droplet sizes across DUCs and accuracy of flow rate modulations demonstrated the potential advantage of using the air-pinch PWM solenoid valve as an alternative for precision variable-rate sprayers to accurately apply different chemicals. Keywords: Droplet size, Flow rate control, Pesticide, Pinch valve, Precision farming, Pulse width modulation.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135214085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calibration and Validation of RZWQM2-P Model to Simulate Phosphorus Loss in a Clay Loam Soil in Michigan","authors":"Md Sami Bin Shokrana, E. Ghane, Z. Qi","doi":"10.13031/ja.15283","DOIUrl":"https://doi.org/10.13031/ja.15283","url":null,"abstract":"Highlights RZWQM2-P was tested and validated for clay loam soil using daily discharge and load data. The model performed satisfactorily in predicting hydrology and TP load, but DRP prediction was unsatisfactory. Inability of the model to simulate P loss in subsurface drainage discharge after fertilization event was one of the reasons for the unsatisfactory model performance. Abstract. Phosphorus (P) loss and transport through subsurface drainage systems is a primary focus for addressing harmful algal blooms in freshwater systems. The recent development of the phosphorus (P) routine of the Root Zone Water Quality Model (RZWQM2-P) has the potential to enhance our understanding of the fate and transport of P from subsurface-drained fields to surface water. However, there is a need to test the model under different fertilization, soil, climate, and cropping conditions. The objective of this study was to test the model's performance with daily drainage discharge, dissolved reactive phosphorus (DRP), and total phosphorus (TP) load collected from a subsurface-drained field with clay loam soil. We calibrated RZWQM2-P using two years of measured data. Subsequently, we validated RZWQM2-P using a year and nine months of measured data. We used the Nash-Sutcliffe model efficiency (NSE) and percentage bias (PBIAS) statistics for the RZWQM2-P model evaluation. The results showed that the model performance was “good” (daily NSE = 0.66 and PBIAS = -7.16) in predicting hydrology for the calibration period. For the validation period, the hydrology prediction of the model was “very good” (daily NSE = 0.76), but it had a “satisfactory” underestimation bias (PBIAS = 23.57). The model’s performance was “unsatisfactory” in simulating DRP for both calibration (daily NSE = 0.31 and PBIAS = -61.50) and validation (daily NSE = 0.32 and PBIAS = 43.68) periods. The P model showed “satisfactory” performance in predicting TP load for both calibration (daily NSE = 0.46 and PBIAS = -32.41) and validation (daily NSE = 0.39 and PBIAS = 42.90) periods, although both periods showed “unsatisfactory” percent bias. The underperformance may have been due to the model’s inability to partition fertilizer P into different P pools under high water tables or ponding conditions when using daily data. In conclusion, the RZWQM2-P model performed well for drainage discharge with daily data, but further investigation is needed to improve the P component of the model. Keywords: Field-scale modeling, Nutrient load, Phosphorus modeling, Subsurface drainage, Tile drainage, Water Quality.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"176 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73169360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Properties of Commercially Available Hermetic Storage Bag Liners","authors":"M. Ignacio, D. Maier, K. Vorst","doi":"10.13031/ja.15366","DOIUrl":"https://doi.org/10.13031/ja.15366","url":null,"abstract":"Highlights Fundamental engineering properties of hermetic bag liners were identified and measured to establish specifications for a new ASABE X657 standard for measurement and rating the performance of gas barrier liners in hermetic storage bags. Results showed strong evidence of differences in properties among six types of commercially available hermetic bag gas barrier liners (P<0.05). Critical gas barrier properties (OTR and WVTR) were measured to assess their ability to maintain initial conditions (“hermeticity”). Critical mechanical properties, such as impact failure weight, penetration resistance, and tear strength, were measured to determine their durability during handling and storage. Abstract. The impacts of hermetic storage bag technology on food security are well established. However, understanding the hermetic bag liner's mechanical and barrier properties with its useful life and efficacy are needed to ensure the continued successful adoption of this critically important storage technology to control biological activity. The goals of this study were to identify and quantify fundamental engineering properties as a basis for establishing an American Society of Agricultural and Biological Engineers (ASABE) engineering standard for testing and rating the hermeticity of gas barrier liners in storage bags for smallholder farmers. Six commercially available hermetic storage bag liners (AgroZ, Elite, PICS, GrainPro, Storezo, Zerofly) were evaluated for mechanical properties (tensile, impact, tear, penetration resistance) and barrier properties (oxygen transmission rate and water-vapor transmission rate) following American Society for Testing and Materials (ASTM) test methods. Results indicate significant differences (P< 0.05) in material properties among brands of storage bag liners. Values for oxygen and water vapor transmission rates were determined to ensure hermetic conditions can be achieved. Values for mechanical properties (yield and tensile strength, elongation, and toughness, tear strength, penetration resistance and impact failure weight) of gas barrier liners were quantified to ensure acceptable performance of hermetic storage bags. Keywords: Elongation, Hermetic storage, Hermetic storage bags, Impact failure weight, Oxygen Transmission Rates (OTR), Penetration resistance, Tear strength, Tensile strength, Toughness, Water Vapor Transmission Rate (WVTR), Yield strength.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73871016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Depth Camera Potentials for Variable-Rate Sprayers","authors":"H. Jeon, Heping Zhu","doi":"10.13031/ja.15070","DOIUrl":"https://doi.org/10.13031/ja.15070","url":null,"abstract":"Highlights A commercial depth camera with a custom-designed graphical user interface was evaluated to detect tree canopy. Measurement variations under different indoor conditions were negligible for practical applications. Measurement errors ranged from 2.8% to 15.8%, which were acceptable for outdoor applications. Variation of crabapple canopy detection rate was less than 6% from sunrise to sunset. Abstract. To reduce crop protection product use and environmental impacts while maintaining application efficacy and convenience for applicators, an automatic variable rate sprayer coupled with a canopy detection sensor is required. A commercial depth camera was tested as a means of detecting the canopy of ornamental and tree crops for the sprayer. A custom-designed graphical user interface was developed to control the depth camera and save RGB and IR images and depth data to a local computer. Indoor evaluations showed that measurements could be influenced by the temperature and illumination; however, the influence was minimal, with a relative error of less than 1% and a maximum difference of 14 mm between the average measurements. The depth camera was able to detect a 31% to 72% area of a 20-mm wide target, and the rates went up 72% to 89% when the target width increased to 40 mm. The depth camera showed acceptable performance in detecting canopy contour changes and had measurement errors of 2.8% to 15.3% while detecting the distances to outdoor crabapple and oak trees. In addition, the depth camera detected tree canopy in various outdoor conditions from sunrise to sunset with reasonable accuracy (less than 10% of relative errors). In terms of measurement stability, the depth camera detected crabapple canopy with less than 6% variations under various illuminations between sunrise and sunset. The results suggested that the performance of the depth camera was adequate for detecting canopy under outdoor conditions for future variable-rate spray applications in ornamental and tree crop production. In addition, the study outlined the performance of the depth camera, which provided a guideline for future applications. Keywords: Machine Vision, Precision Agriculture, Specialty Crop, Stereo Vision, Variable Rate Application.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73820361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}