As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a ren...As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a renewable energy source. When farming, one of the most important considerations is efficiency. This consists of several factors, including time, fuel use, economic and power efficiencies of equipment. Inefficient field operations could increase harvesting costs and in turn could cause hesitation when a farmer decides to participate in biomass production. This literature review will cover the main elements of biomass and biomass handling relating to determining harvesting efficiency and biomass quality for switchgrass round bales. Specifically, the following sections include past research activities relating to biomass harvesting, biomass bale quality during outdoor storage, logistics models, and data collection methods during biomass harvesting. The objective of this review is to examine status and needs for switchgrass round bale harvesting operations and the expenses that come with it.展开更多
The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Base...The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Based on an exponent model, the testing coefficients of straw bale were estimated using Levenberg-Marquardt Method. The results of test showed that the relation between failure density and loading ability and compressing energy was linear in the phase of high density. The loading ability of straw bale could meet the building bill.展开更多
The study was conducted on Berbere Forest in Bale Zone of Oromia Regional State, south east of Ethiopia with the objective of determining the structural analysis and natural regeneration status of the forest. Systemat...The study was conducted on Berbere Forest in Bale Zone of Oromia Regional State, south east of Ethiopia with the objective of determining the structural analysis and natural regeneration status of the forest. Systematic sampling method was used to collect vegetation data. Seventy two nest quadrat sizes of 400 m2 (20 m × 20 m) for trees and shrubs were used. Within the main quadrat, two opposite side of each sub-quadrat of 25 m2 (5 m × 5 m) for sapling, 4 m2 (2 m × 2 m) for seedling of woody plants. The diameter and height were measured for all individual trees and shrubs having DBH (Diameter at Breast Height) ≥ 10 cm thick and ≥2 m height by using a diameter tape or caliper and clinometer respectively. For description and analysis of vegetation structure Diameter at Breast Height (DBH), basal area, tree density, height, frequency and important value index were used. Structural analysis of some selected tree species was revealed four different population patterns (bell shaped, inverted J-shaped, irregular and U-shaped). The total basal area of Berbere forest was 87.49 m2/ha, but most of the basal area was contributed by few large sized Moraceae family (Ficus vasta, Ficus ovate and Ficus thonningii) plant species. Analysis of regeneration status of woody plants in the forest showed 37.09% trees/shrubs species exhibited “good”, 19.35% showed “fair”, 6.45% showed “poor” and 25.81% trees/shrubs species were “not regenerating” at all and 11.29% trees/shrubs species were available only in sapling or seedling stage. Studies on the structure and regeneration of the forest indicated that there are species that require urgent conservation measures. Therefore, based on the results of this study, we recommended detail regenerating studies of seed bank in relation to various environmental factors such as soil type and properties.展开更多
Loading ability of straw bales was tested by using an Electronical Testing Machine. Linear regression models were proposed to describe the loading ability as a function of failure density and compressing energy. Based...Loading ability of straw bales was tested by using an Electronical Testing Machine. Linear regression models were proposed to describe the loading ability as a function of failure density and compressing energy. Based on an exponent model, the testing compression coefficients of straw bales were estimated by using the Levenberg-Marquardt Method. Results showed that the relation among failure density, loading ability and compressing energy was linear in the phase of high density, Loading ability of straw bales could meet the requirement for building bills .展开更多
Digitalization has nowadays raised interest in variable applications of farming.Increase of knowledge level,by means of unique identification,automation and control,farmers gain relevant business profit.This research ...Digitalization has nowadays raised interest in variable applications of farming.Increase of knowledge level,by means of unique identification,automation and control,farmers gain relevant business profit.This research is focused on the utilization of passive radio frequency identification(RFID)technology in silage bale application,both manual and automated level.Challenges arise due to silage conservation,varying environmental and seasonal conditions,different identification environments and RFID operation principle.Further maximum communication signal strength is limited by telecommunication standard regulations(e.g.,ETSI).The applicability of RFID technology with different commercial passive transponders is measured manually in a silage bale of 160 cm in diameter,covering 360 degrees around the bale.In addition,automated field tests are conducted in a real environment,where the data collection system is appended to a tractor and RFID reader antenna in a baler.Manual measurements are conducted as identification distance(meters)and transponder population(number of tags),while automated measurements are based on the number of successfully identified silage bales.Based on the manual measurement results,the most suitable tags for the automated field measurements were chosen,and the applicability to silage bale identification was verified.Field tests showed 100%success,with 151/151 uniquely identified silage bales.Achieved results prove that passive RFID operates well enough in silage bale identification,further enabling the development of digitalization of silage bale life cycle.展开更多
The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregi...The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregion has been characterized primarily by recurring floods and droughts,as well as crop failure due to a variety of natural and human-activity-driven change factors.As a matter of fact,the purpose of this study would be to examine long-term changes and fluctuation in precipitation(PCP),maximum temperature(T_(max)),and minimum temperature(T_(min))in the Bale mountains ecoregion using ensembles of three climate models with three representative concentration pathways(RCPs)scenarios from the coupled model inter-comparison project phase five(CMIP5)dataset.Statistical downscaling model(SDSM)was applied to project PCP,T_(max),and T_(min)in the forthcoming period considering three RCPs:low emission(RCP2.6),intermediate(RCP4.5),and high emission(RCP8.5).SDSM's performance in capturing historical daily PCP,T_(max),and T_(min)has been validated using standard statistical metrics such as coefficient of determination(R^(2)),Nash Sutcliff efficiency(NSE),and root mean square error(RMSE).SDSM has the potential to generate a statistical transfer function between large-scale variables and local climate,allowing PCP,T_(max),and T_(min) to be downscaled to a point scale for the ecoregion.The magnitude of mean yearly changes in PCP,T_(max),and T_(min) were investigated throughout three thirty-year time slices,corresponding to the 2020s,2050s,and 2080s.The Mann-Kendall non-parametric test was used to analyse trends in PCP,T_(max),and T_(min) from 2011 to 2100.Inter-annual variability in PCP,T_(max),and T_(min) were investigated for the aforementioned period,taking standard deviation into account under each RCP scenarios.The results reveal that mean annual PCP,T_(max),and T_(min) are rising in all three time slices and in all three CMIP5 RCP scenarios as compared to the baseline scenario.Mean annual PCP is projected to increase within the uncertainty range of 6.68% to 17.93%(RCP2.6),7.45% to 21.94%(RCP4.5),and 19.70% to 33.69%(RCP4.5)(RCP8.5).T_(max) increases from 0.04℃ to 0.24℃(RCP2.6),0.05℃ to 0.31℃(RCP4.5),and 0.04℃ to 0.42℃(RCP8.5),whereas T_(min) increases from 0.22℃ to 0.52℃(RCP2.6),0.23℃ to 0.67℃(RCP4.5),and 0.26℃ to 1.14℃(RCP8.5)(RCP8.5).For future projections at the end of the 21^(st) century,the mean annual PCP,T_(max),and T_(min) for all three analysed climate models and RCPs have shown a positive trend.The inter-annual variability of PCP,T_(max),and T_(min) is higher in the RCP8.5 than RCP4.5 and RCP2.6 in all climate models.The findings clearly implied that prior understanding of long-term climate change and variability need to be addressed to plan effective and efficient mitigation strategies,as well as to maintain adequate quantity and quality of water supplies to the communities residing in the ecoregion.展开更多
文摘As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a renewable energy source. When farming, one of the most important considerations is efficiency. This consists of several factors, including time, fuel use, economic and power efficiencies of equipment. Inefficient field operations could increase harvesting costs and in turn could cause hesitation when a farmer decides to participate in biomass production. This literature review will cover the main elements of biomass and biomass handling relating to determining harvesting efficiency and biomass quality for switchgrass round bales. Specifically, the following sections include past research activities relating to biomass harvesting, biomass bale quality during outdoor storage, logistics models, and data collection methods during biomass harvesting. The objective of this review is to examine status and needs for switchgrass round bale harvesting operations and the expenses that come with it.
基金Supported by the Returnee Foundation of Ministry of Education and Project (1054hz023)Supported by the Key Research Foundation of Ministry of Science in Heilongjiang Province
文摘The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Based on an exponent model, the testing coefficients of straw bale were estimated using Levenberg-Marquardt Method. The results of test showed that the relation between failure density and loading ability and compressing energy was linear in the phase of high density. The loading ability of straw bale could meet the building bill.
文摘The study was conducted on Berbere Forest in Bale Zone of Oromia Regional State, south east of Ethiopia with the objective of determining the structural analysis and natural regeneration status of the forest. Systematic sampling method was used to collect vegetation data. Seventy two nest quadrat sizes of 400 m2 (20 m × 20 m) for trees and shrubs were used. Within the main quadrat, two opposite side of each sub-quadrat of 25 m2 (5 m × 5 m) for sapling, 4 m2 (2 m × 2 m) for seedling of woody plants. The diameter and height were measured for all individual trees and shrubs having DBH (Diameter at Breast Height) ≥ 10 cm thick and ≥2 m height by using a diameter tape or caliper and clinometer respectively. For description and analysis of vegetation structure Diameter at Breast Height (DBH), basal area, tree density, height, frequency and important value index were used. Structural analysis of some selected tree species was revealed four different population patterns (bell shaped, inverted J-shaped, irregular and U-shaped). The total basal area of Berbere forest was 87.49 m2/ha, but most of the basal area was contributed by few large sized Moraceae family (Ficus vasta, Ficus ovate and Ficus thonningii) plant species. Analysis of regeneration status of woody plants in the forest showed 37.09% trees/shrubs species exhibited “good”, 19.35% showed “fair”, 6.45% showed “poor” and 25.81% trees/shrubs species were “not regenerating” at all and 11.29% trees/shrubs species were available only in sapling or seedling stage. Studies on the structure and regeneration of the forest indicated that there are species that require urgent conservation measures. Therefore, based on the results of this study, we recommended detail regenerating studies of seed bank in relation to various environmental factors such as soil type and properties.
基金Supported by National Natural Science Fund(50675071)Specialized Research Fund for Doctoral Program of Higher Education(20060564009)
文摘Loading ability of straw bales was tested by using an Electronical Testing Machine. Linear regression models were proposed to describe the loading ability as a function of failure density and compressing energy. Based on an exponent model, the testing compression coefficients of straw bales were estimated by using the Levenberg-Marquardt Method. Results showed that the relation among failure density, loading ability and compressing energy was linear in the phase of high density, Loading ability of straw bales could meet the requirement for building bills .
文摘Digitalization has nowadays raised interest in variable applications of farming.Increase of knowledge level,by means of unique identification,automation and control,farmers gain relevant business profit.This research is focused on the utilization of passive radio frequency identification(RFID)technology in silage bale application,both manual and automated level.Challenges arise due to silage conservation,varying environmental and seasonal conditions,different identification environments and RFID operation principle.Further maximum communication signal strength is limited by telecommunication standard regulations(e.g.,ETSI).The applicability of RFID technology with different commercial passive transponders is measured manually in a silage bale of 160 cm in diameter,covering 360 degrees around the bale.In addition,automated field tests are conducted in a real environment,where the data collection system is appended to a tractor and RFID reader antenna in a baler.Manual measurements are conducted as identification distance(meters)and transponder population(number of tags),while automated measurements are based on the number of successfully identified silage bales.Based on the manual measurement results,the most suitable tags for the automated field measurements were chosen,and the applicability to silage bale identification was verified.Field tests showed 100%success,with 151/151 uniquely identified silage bales.Achieved results prove that passive RFID operates well enough in silage bale identification,further enabling the development of digitalization of silage bale life cycle.
文摘The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregion has been characterized primarily by recurring floods and droughts,as well as crop failure due to a variety of natural and human-activity-driven change factors.As a matter of fact,the purpose of this study would be to examine long-term changes and fluctuation in precipitation(PCP),maximum temperature(T_(max)),and minimum temperature(T_(min))in the Bale mountains ecoregion using ensembles of three climate models with three representative concentration pathways(RCPs)scenarios from the coupled model inter-comparison project phase five(CMIP5)dataset.Statistical downscaling model(SDSM)was applied to project PCP,T_(max),and T_(min)in the forthcoming period considering three RCPs:low emission(RCP2.6),intermediate(RCP4.5),and high emission(RCP8.5).SDSM's performance in capturing historical daily PCP,T_(max),and T_(min)has been validated using standard statistical metrics such as coefficient of determination(R^(2)),Nash Sutcliff efficiency(NSE),and root mean square error(RMSE).SDSM has the potential to generate a statistical transfer function between large-scale variables and local climate,allowing PCP,T_(max),and T_(min) to be downscaled to a point scale for the ecoregion.The magnitude of mean yearly changes in PCP,T_(max),and T_(min) were investigated throughout three thirty-year time slices,corresponding to the 2020s,2050s,and 2080s.The Mann-Kendall non-parametric test was used to analyse trends in PCP,T_(max),and T_(min) from 2011 to 2100.Inter-annual variability in PCP,T_(max),and T_(min) were investigated for the aforementioned period,taking standard deviation into account under each RCP scenarios.The results reveal that mean annual PCP,T_(max),and T_(min) are rising in all three time slices and in all three CMIP5 RCP scenarios as compared to the baseline scenario.Mean annual PCP is projected to increase within the uncertainty range of 6.68% to 17.93%(RCP2.6),7.45% to 21.94%(RCP4.5),and 19.70% to 33.69%(RCP4.5)(RCP8.5).T_(max) increases from 0.04℃ to 0.24℃(RCP2.6),0.05℃ to 0.31℃(RCP4.5),and 0.04℃ to 0.42℃(RCP8.5),whereas T_(min) increases from 0.22℃ to 0.52℃(RCP2.6),0.23℃ to 0.67℃(RCP4.5),and 0.26℃ to 1.14℃(RCP8.5)(RCP8.5).For future projections at the end of the 21^(st) century,the mean annual PCP,T_(max),and T_(min) for all three analysed climate models and RCPs have shown a positive trend.The inter-annual variability of PCP,T_(max),and T_(min) is higher in the RCP8.5 than RCP4.5 and RCP2.6 in all climate models.The findings clearly implied that prior understanding of long-term climate change and variability need to be addressed to plan effective and efficient mitigation strategies,as well as to maintain adequate quantity and quality of water supplies to the communities residing in the ecoregion.
