[Objectives]To establish an integrated agro-aquaculture ecological farming model by combining in-pond cage fish farming,water circulation systems,and rice cultivation on bio-floating beds,and compared it with traditio...[Objectives]To establish an integrated agro-aquaculture ecological farming model by combining in-pond cage fish farming,water circulation systems,and rice cultivation on bio-floating beds,and compared it with traditional pond farming.[Methods]The research was carried out in 3 test ponds and 3 control ponds.A 6 m×9 m×2.5 m cage was set every 667 m 2 in the test pond,and water circulator and microporous oxygenation equipment were installed.Ecological floating beds were set on both sides of the pond.Common aeration equipment was used for control ponds.The same number and size of crucian carp,and the same number,proportion and size of silver carp and bighead carp were raised in both the test and control groups.Total nitrogen,ammonium nitrogen,total phosphorus and phosphate content was determined every 15 d,and growth indicators and feed conversion ratios of fish were measured at the end of the experiment.[Conclusions]The content of total nitrogen,ammonium nitrogen,total phosphorus and phosphate in the experimental group decreased by 50.69%,69.12%,62.62%and 54.20%,respectively,compared with the control group.Compared with the control group,the harvest size,survival rate and yield per unit area of crucian carp in the experimental group increased by 5.25%,7.58%and 13.28%,respectively,and the feed conversion ratio decreased by 4.72%.[Results]The integrated agro-aquaculture model demonstrated significant advantages in mitigating eutrophication,improving yield,and enhancing feed efficiency.展开更多
This paper addresses the complexity of wake control in large-scale wind farms by proposing a partitioning control algorithm utilizing the FLORIDyn(FLOW Redirection and Induction Dynamics)dynamic wake model.First,the i...This paper addresses the complexity of wake control in large-scale wind farms by proposing a partitioning control algorithm utilizing the FLORIDyn(FLOW Redirection and Induction Dynamics)dynamic wake model.First,the impact of wakes on turbine effective wind speed is analyzed,leading to a quantitative method for assessing wake interactions.Based on these interactions,a partitioning method divides the wind farm into smaller,computationally manageable zones.Subsequently,a heuristic control algorithm is developed for yaw optimization within each partition,reducing the overall computational burden associated with multi-turbine optimization.The algorithm’s effectiveness is evaluated through case studies on 11-turbine and 28-turbine wind farms,demonstrating power generation increases of 9.78%and 1.78%,respectively,compared to baseline operation.The primary innovation lies in coupling the higher-fidelity dynamic FLORIDyn wake model with a graph-based partitioning strategy and a computationally efficient heuristic optimization,enabling scalable and accurate yaw control for large wind farms,overcoming limitations associated with simplified models or centralized optimization approaches.展开更多
Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in stre...Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in strengthening climate-smart coastal farming system to enhance coastal agricultural sustainability.A mixed-methods study was conducted in the southwestern coastal region of Bangladesh in 2023,which involved administering a structured questionnaire and conducing face-to-face interviews with 390 farmers.Perceived role index(PRI)was employed to assess the potential role of AEAS.To forecast the perceived role outcomes,the machine learning model was undertaken by utilizing suitable algorithms.Additionally,feature importance was calculated to underpin the significant factors of perceived role outcomes.The findings showed that coastal farming communities held a comprehensive understanding of the role of AEAS.Key roles included diffusion of agricultural innovations,acting as a bridge between farmers and research organizations,using demonstration techniques to educate farmers,training farmers on food storage,processing,and utilization,and promoting awareness and adoption of best practices.The machine learning model exposed a significant relationship between farmers’socio-economic characteristics and their perception behavior.The results identified that factors like innovativeness,awareness,training exposure,access to AEAS,and access to information significantly influenced how farmers perceived the efficacy of AEAS in promoting a smart coastal farming system.However,farmers confronted multiple constraints in receiving demand-driven services and maintaining coastal farm sustainability.These insights can guide concerned authorities and policy-makers in providing AEAS for the purpose of strengthening climate-smart coastal farming system,particularly with a special focus on capacity building programs and machine learning application.Moreover,the outcomes of this study can assist the authorities of similar coastal systems throughout the world to initiate potential strategies for enhancing region-specific agricultural sustainability.展开更多
About 44%of the world’s cocoa is produced in one single country,Côte d’Ivoire.Providing this important raw material,most Ivorian cocoa farmers live in severe poverty,which,despite a multitude of sector interven...About 44%of the world’s cocoa is produced in one single country,Côte d’Ivoire.Providing this important raw material,most Ivorian cocoa farmers live in severe poverty,which,despite a multitude of sector interventions,is still widespread,affecting social and environmental sustainability in cocoa production.In this context,cocoa farmers are still often treated as a homogeneous group of small-scale producers(mainly males),resulting in interventions being conceptualized as one-size-fits-all approaches and failing to deliver support schemes that take farmers’specific conditions appropriately into account.Applying a broader typology approach that combines farm characteristics with farmers’characteristics,this study aims to delineate Ivorian cocoa farmers and their farms into specific types in order to improve advice for targeted sustainability interventions and living income(LI)potentials.Principal component analysis and hierarchical clustering analysis of a household dataset collected in 2022 in five cocoa-growing regions of Côte d’Ivoire were chosen to identify types of male-headed farms.To assure gender sensitive analysis,a female-headed farm type was created artificially.The specific characteristics of the identified types were captured using descriptive analysis.Descriptive statistics and non-parametric tests were then applied to examine the relationships between these farm types and various outcomes.Additionally,a binary logistic model was used to estimate the probability of these links in relation to variables relevant for achieving a LI.Finally,Spearman non-parametric correlation was used to identify eventual differences in the strength of relationships between key variables per farm type.Three different types of male-headed farms are identified:type 1(the most productive and diversified farms with larger size),type 2(middle-sized farms with strong focus on cash crops),and type 3(small-sized farms with a good level of diversification for self-consumption).The artificially created type 4 represents female-headed farms with the smallest size.On average,none of these farm types achieves a LI.However,type 1 shows the smallest LI gap,while type 4 is by far the worst.Our analyses reveal underlying socio-economic factors systematically disadvantaging female-headed cocoa farms,most notably limited access to land and other material assets.The key contribution of this study lies in the empirical identification of the different characteristics of farms in a given farming system,thereby identifying the need for targeted support interventions.Type-specific recommendations are made,showing pathways to provide tailored programs to farmers of different types in order to reduce their LI gaps.展开更多
Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate c...Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate change on the ecosystem and the rise in methane emissions,it is essential to conduct a bibliometrics study to provide an overview and research trends.We used the Bibliometrix package and VOSviewer to decipher bibliometric indices for methane emissions in cattle farms(MECF).Current dataset were collected from the Web of Science(Core Collection)database,and 8,998 publications were analyzed.The most co-occurring keywords scientists preferred were methane(1,528),greenhouse gas(443),methane emissions(440),and cattle(369).Methane was the most frequently used keyword in the published scientific literature.Thematic evolution of research themes and trend results highlighted carbon dioxide,methane,dairy cattle,cattle,and risk factors during 1999–2017.Chinese Academy of Sciences ranked on top with 485 publications,followed by Agriculture&Agri-Food Canada,University of Colorado,National Oceanic and Atmospheric Administration,and Aarhus University.Chinese Academy of Sciences was also the most cited organization,followed by the University of Colorado,Agriculture&Agri-Food Canada,National Oceanic and Atmospheric Administration,and United States Geological Survey.Source analysis showed that the Science of the Total Environment was cited with the highest total link strength.Science of the Total Environment ranked first in source core 1 with 290 citation frequencies,followed by Journal of Dairy Science with 223 citation frequencies.Currently,no bibliometric study has been conducted on MECF,and to fill this knowledge gap,we carried out this study to highlight methane emissions in cattle farms,aiming at a climate change perspective.In this regard,we focused on the research productivity of countries authors,journals and institutions,co-occurrence of keywords,evolution of research trends,and collaborative networking.Based on relevance degree of centrality,methane emissions and greenhouse gases appeared as basic themes,cattle,and dairy cattle appeared as emerging/declining themes,whereas,methane,greenhouse gas and nitrous oxide appeared to fall amongst basic and motor themes.On the other hand,beef cattle,rumen and dairy cow seem to be between motor and niche themes,and risk factors lie in niche themes.The present bibliometric analysis provides research progress on methane emissions in cattle farms.Current findings may provide a framework for understanding research trends and themes in MECF research.展开更多
In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. ...In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. A five-step method and descriptive analysis were used on a sample of 250 farmers. The degree of damage caused by pests and crop diseases is significant, with respective proportions of 52.50% and 40.40%. It appears that the main climate risk factors for vulnerability are droughts, floods, soil degradation, and pest invasions. Additionally, the average level of exposure to agricultural operations is very high, with an index of 0.6. The sensitivity index remained constant in the range of 0.3 to 0.6 and is significant (reaching an index of 0.8). However, 61.2% of farms have a medium level of vulnerability and 33.3% have a high vulnerability to the effects of climate change. Nonetheless, a concerning trend regarding the vulnerability of farms has been observed. To assist policymakers and development actors in improving the vulnerability level of these production units, four phases of action are proposed: a diagnostic phase, evaluation, estimation of adaptation needs, implementation, and proper monitoring of actions.展开更多
Climate change is becoming a major issue for agriculture and the well-being of farmers. The objective of this article is to identify and analyze the production factors that may influence the competitiveness level of a...Climate change is becoming a major issue for agriculture and the well-being of farmers. The objective of this article is to identify and analyze the production factors that may influence the competitiveness level of agricultural operations, as well as to establish a structural and functional typology of these farms. Using Principal component analysis (PCA) combined with hierarchical ascending classification (HAC) on 250 farmers, the study was able to set farms typology. Furthermore, variance analysis and econometric models (linear et quadratic) were also used for in-depth analysis. The results show the existence of three groups of farm (GA, GB, GC): GA (19.7%), GB (65.3%), and GC (15%). Drought spells and flood are the main climatic risks affecting rain-fed farm operations. For irrigated crops such as rice, the major constraints remain bird attacks, the invasion of pests and nematodes. Climate variability significantly increases the prevalence of morbidities in the region by raising the number of inactive individuals. This significantly and differentially affects the outcomes of these assets. Health expenditures represent a significant share (GB: 12% and GC: 11%) and a non-negligible share (GA: 8.4%). However, larger participations (GC) show better economic performance due to economies of scale, but all categories would benefit from adopting appropriate strategies to reduce losses and increase their resilience.展开更多
Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions var...Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions varies significantly from one farmer to another, making it challenging to accurately estimate crop production through crop models. This limitation has implications for the reliability of using crop models as agricultural decision-making support tools. To support decision making in agriculture, an approach combining a genetic algorithm (GA) with the crop model AquaCrop is proposed for a location-specific calibration of maize cropping. In this approach, AquaCrop is used to simulate maize crop yield while the GA is used to derive optimal parameters set at grid cell resolution from various combinations of cultivar parameters and crop management in the process of crop and management options calibration. Statistics on pairwise simulated and observed yields indicate that the coefficient of determination varies from 0.20 to 0.65, with a yield deviation ranging from 8% to 36% across Burkina Faso (BF). An analysis of the optimal parameter sets shows that regardless of the climatic zone, a base temperature of 10˚C and an upper temperature of 32˚C is observed in at least 50% of grid cells. The growing season length and the harvest index vary significantly across BF, with the highest values found in the Soudanian zone and the lowest values in the Sahelian zone. Regarding management strategies, the fertility mean rate is approximately 35%, 39%, and 49% for the Sahelian, Soudano-sahelian, and Soudanian zones, respectively. The mean weed cover is around 36%, with the Sahelian and Soudano-sahelian zones showing the highest variability. The proposed approach can be an alternative to the conventional one-size-fits-all approach commonly used for regional crop modeling. Moreover, it has the potential to explore the performance of cropping strategies to adapt to changing climate conditions.展开更多
The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is t...The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is to analyze these impacts of climate disruption on the economic performance of farms. The methodology adopted for this study combined documentary research with field surveys conducted on a sample of 250 randomly selected farmers. The analytical methods used mainly consisted of linear regression, profitability calculations, and linear programming. The findings indicate that all productions across different crops have experienced a decrease over the past 30 years. For instance, the production of millet, sorghum, and cowpea, which were respectively 812 kg/ha, 260 kg/ha, and 100 kg/ha between the last 30 and 20 years, has now dropped to 412 kg/ha, 106 kg/ha, and 46 kg/ha respectively. A negative and significant effect on agricultural net margin was observed due to variables such as flooding, drought, pest invasion in rice fields, and temperature changes. Smallholder farms show a relatively low margin (46%) to cover their fixed costs, which may indicate a risk if fixed expenses are high. Furthermore, the analysis results from linear programming reveal that farmers could achieve an additional net profit per hectare of 116,861 FCFA, 217201.5 FCFA, and 291988.2 FCFA respectively for small, medium, and large producers by managing variable costs and health-related expenses for households.展开更多
In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of th...In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of the paper the artistic achievements of his masterpiece“The Lucky Purse”are explored.展开更多
As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed...As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed in many wind farms.However,studies have shown that when the three-phase short-circuit fault occurs in the wind farm,the transient overcurrent during the fault occurrence and fault clearance is suppressed,making it difficult for GF-SVG to use traditional fixed virtual impedance.Aiming at the problem,firstly,the influence of virtual reactance on control stability is analyzed using the GF-SVG’s current open-loop transfer function.Secondly,based on the existing current limitation strategies of GF-SVG,an adaptive virtual reactance current limitation strategy suitable for symmetrical faults of the power grid is proposed,which limits GF-SVG’s transient overcurrent during fault occurrence and fault clearance stage to the tolerance range of GF-SVG’s power devices.Based on the GF-SVG’s active power loop and reactive power loop small signal models,the availability of the proposed adaptive virtual reactance in suppressing the DC voltage drop of GF-SVG is analyzed,and shortening the transient overvoltage recovery time of the wind farm after the fault clearance is also discussed.Finally,electromagnetic simulation proves the effectiveness and correctness of the proposed adaptive current limitation method.展开更多
The increasing conversion of agricultural land to organic farming requires the development of specifically adapted cultivars.So far,in tomato there is lack of research for selection of germplasm suitable for sustainab...The increasing conversion of agricultural land to organic farming requires the development of specifically adapted cultivars.So far,in tomato there is lack of research for selection of germplasm suitable for sustainable agroecosystems.In this study,we investigated the genotypic and environmental factors affecting the variation of plant,fruits,and root traits in 39 tomato genotypes grown under organic farming conditions.Four independent experiments were conducted in Italy and Spain across two consecutive seasons in 2019 and 2020.For all traits,the factorial linear regression model to estimate the main effects of genotype(G),location(L),year of cultivation(Y)and their interactions,revealed highly significant(P<0.001)variations,with the G factor being largely predominant for most traits.The implementation of the“which-won-where”,“mean performance versus stability”and“discriminative vs representativeness”patterns in the GGE(Genotype plus Genotype by Environment interaction)analysis,allowed the identification of superior cultivars with high stability across the testing environments.Genomic characterization with 30890 high quality SNPs from dd RADseq genotyping analysis,revealed that a specific cluster of cherry tomato accessions were low performing in terms of yield and fruit weight,on the contrary,showed a high content of soluble solids,which in agreement with GGE analysis.Results of this study provide a framework for the potential use of this locally adapted tomato germplasm to address the needs of more sustainable agriculture.展开更多
The rapid expansion of tobacco farming poses a significant threat to biodiversity in Yunnan Province,China,a region known for its rich biodiversity.This study aims to understand the trade-offs between tobacco farming ...The rapid expansion of tobacco farming poses a significant threat to biodiversity in Yunnan Province,China,a region known for its rich biodiversity.This study aims to understand the trade-offs between tobacco farming and higher plant species diversity,and to identify priority counties for conservation.We employed an integrated approach combining species distribution modeling,GIS overlay analysis,and empirical spatial regression to em pirically assess the impact of tobacco farming intensity on biodiversity risk.Our findings reveal a compelling negative spatial correlation between tobacco farming expansion and higher plant species diversity.Specifically,southern counties in Wenshan and Honghe prefectures are major priority areas of conservation that exhibit signif icant spatial correlations between biodiversity risks and high tobacco farming intensity.Quantitatively,at county level,a 1%increase in tobacco farming area corresponds to a 0.094%decrease in endemic higher plant species richness across the entire province.These results underscore the need for targeted and region-specific regulations to mitigate biodiversity loss and promote sustainable development in Yunnan Province.The integrated approach used in this study provides a comprehensive assessment of the tobacco-biodiversity trade-offs,offering actionable insights for policymaking.展开更多
Intensive farming practices,aimed at maximizing crop yields through substantial inputs of labour,technology,and chemical fertilizers,have significantly transformed modern agriculture.However,these methods have raised ...Intensive farming practices,aimed at maximizing crop yields through substantial inputs of labour,technology,and chemical fertilizers,have significantly transformed modern agriculture.However,these methods have raised serious concerns regarding soil health,environmental sustainability,and long-term agricultural viability.This study examines the ecological impact of intensive farming on soil health in the KB Asifabad District of Telangana,India,where traditional and modern farming techniques coexist.The objectives include analysing socio-economic factors influencing farming methods,evaluating the impact of tilling techniques and fertilizer use on soil health,and promoting sustainable practices through education and policy recommendations.Findings reveal a strong reliance on chemical fertilizers,with 98.3% of farmers using them exclusively due to their perceived efficiency and rapid results.However,this overdependence has led to soil degradation,reduced microbial diversity,and environmental pollution.Conversely,despite its ecological benefits,natural manure remains underutilized due to scepticism and economic constraints.Mechanical tilling methods,while effective,have negatively impacted soil structure and fertility.The study highlights the necessity of transitioning to sustainable practices,integrating organic inputs,and adopting conservation techniques to restore soil health and ecosystem balance.This research provides practical pathways for achieving sustainable agriculture by integrating traditional knowledge with modern practices.It is particularly relevant for policymakers,agricultural extension services,and farming communities as it highlights the need for educational initiatives,financial incentives,and regulatory measures to ensure long-term soil fertility,environmental stewardship,and improved farmer livelihoods.展开更多
The contamination of pork during breeding can negatively impact both food quality and safety.Sodium dichloroiso-cyanurate(NaDCC),a chlorine-containing disinfectant,is widely used in animal environments.In this study,1...The contamination of pork during breeding can negatively impact both food quality and safety.Sodium dichloroiso-cyanurate(NaDCC),a chlorine-containing disinfectant,is widely used in animal environments.In this study,16S rRNA sequencing was used to determine the bacterial communities in a pork farm.We also assessed the effectiveness of NaDCC disinfection by analyzing microbial diversity.The results revealed that the predominant genera in pork skin samples and environmental samples were Staphylococcus and Acinetobacter,respectively.Escherichia coli and Strep-tococcus equinus were present in all the samples,suggesting that NaDCC is not fully effective in preventing zoonotic pathogen contamination.The Chao1 and Shannon indices for sow skins increased after disinfection.No significant differences were observed in the microbiological composition of sow barn samples before and after disinfection(p>0.1).Additionally,bacterial abundance in sow skin was strongly correlated with abundance on pen floors(r=0.906,p<0.05),indicating potential cross-contamination between these sample types.Conversely,the bacterial abun-dance in the floor samples was weakly correlated with that in the other samples,suggesting that NaDCC is effective as a decontaminant.This study provides valuable insights into microbial contamination on pork farms and under-scores the importance of proper disinfection practices.This study also offers scientific recommendations for improv-ing disinfection protocols.展开更多
This work addresses challenges and opportunities in the evaluation of solar power plant impacts,with a particular focus on thermal effects of solar plants on the environment and vice-versa.Large-scale solar power plan...This work addresses challenges and opportunities in the evaluation of solar power plant impacts,with a particular focus on thermal effects of solar plants on the environment and vice-versa.Large-scale solar power plants are often sited in arid or desert habitats,which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity.Our understanding of both shortwave(solar)and longwave(terrestrial)radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications.In contrast to radiation,the convective environment in large-scale solar power plants is much more difficult to characterize.Wind direction,wind speed,turbulence intensity,dust concentration,ground condition,panel configuration density,orientation and distribution throughout the solar field,all affect the local environment,the balance between radiation and convection,and in turn,the performance and thermal impact of solar power plants.Because the temperatures of the two sides of photovoltaic(PV)panels depend on detailed convection-radiation balances,the uncertainty associated with convection affects the heat and mass transfer balances as well.Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats.Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions.展开更多
Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control ...Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control method for its active-loop parameters is used to realize thewind-farmfrequency support,which has become the current research hotspot.Taking the ESVG with a supercapacitor on the DC side as the research object,the influence trend of the change of virtual rotation inertia and virtual damping coefficient on its virtual angular velocity and power angle is analyzed.Then,the constraint relationship between the equivalent virtual inertia time constant of the supercapacitor and the virtual rotation inertia of the ESVG is clarified.Then,combined with the second-order response characteristics of the ESVG power control loop,the selection principles of the frequency modulation coefficient,the virtual rotation inertia,and the virtual damping coefficient are determined.An ESVG adjustment control method,considering the adaptive adjustment of the active loop parameters of the supercapacitor equivalent inertia,is proposed.While ensuring the frequency support capability of the ESVG,the fluctuation degree of its output active power and the virtual angular velocity are suppressed,and the proposed adjustment method also improves the stability of the ESVG control system and the frequency support capability for the wind farm.Finally,the simulation verifies the correctness of the theoretical analysis and the effectiveness of the proposed strategy.展开更多
[Objectives]This study was conducted to evaluate the practical efficacy of Haemophilus parasuis(Hps)vaccines and determine whether the continuous use of vaccines leads to changes in Hps serotypes.[Methods]A swine prod...[Objectives]This study was conducted to evaluate the practical efficacy of Haemophilus parasuis(Hps)vaccines and determine whether the continuous use of vaccines leads to changes in Hps serotypes.[Methods]A swine production group that had used a bivalent vaccine of Hps serotypes 4 and 5 for two consecutive years were investigated and retrospectively analyzed.Data on Hps detection rate,nursery production and disease indexes,as well as serotype shifts after continuous vaccination,were collected to assess vaccine effectiveness.[Results]Continuous vaccination reduced the total nursery culling and mortality rate by 1.75%.Hps infection persisted in the farms,and the pathogen could still be isolated.However,serotyping revealed a significant shift in the dominant prevalent serotypes,indicating that the vaccine was indeed effective.[Conclusions]The matched Hps vaccine demonstrated effective results.However,whether replacing serotypes or adding more prevalent serotypes could further improve the control of Hps disease requires further investigation.展开更多
Wind energy has emerged as a potential replacement for fossil fuel-based energy sources.To harness maximum wind energy,a crucial decision in the development of an efficient wind farm is the optimal layout design.This ...Wind energy has emerged as a potential replacement for fossil fuel-based energy sources.To harness maximum wind energy,a crucial decision in the development of an efficient wind farm is the optimal layout design.This layout defines the specific locations of the turbines within the wind farm.The process of finding the optimal locations of turbines,in the presence of various technical and technological constraints,makes the wind farm layout design problem a complex optimization problem.This problem has traditionally been solved with nature-inspired algorithms with promising results.The performance and convergence of nature-inspired algorithms depend on several parameters,among which the algorithm termination criterion plays a crucial role.Timely convergence is an important aspect of efficient algorithm design because an inefficient algorithm results in wasted computational resources,unwarranted electricity consumption,and hardware stress.This study provides an in-depth analysis of several termination criteria while using the genetic algorithm as a test bench,with its application to the wind farm layout design problem while considering various wind scenarios.The performance of six termination criteria is empirically evaluated with respect to the quality of solutions produced and the execution time involved.Due to the conflicting nature of these two attributes,fuzzy logic-based multi-attribute decision-making is employed in the decision process.Results for the fuzzy decision approach indicate that among the various criteria tested,the criterion Phi achieves an improvement in the range of 2.44%to 32.93%for wind scenario 1.For scenario 2,Best-worst termination criterion performed well compared to the other criteria evaluated,with an improvement in the range of 1.2%to 9.64%.For scenario 3,Hitting bound was the best performer with an improvement of 1.16%to 20.93%.展开更多
Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine ...Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.展开更多
基金Supported by Jilin Provincial Key Research and Development Project(20230202070NC).
文摘[Objectives]To establish an integrated agro-aquaculture ecological farming model by combining in-pond cage fish farming,water circulation systems,and rice cultivation on bio-floating beds,and compared it with traditional pond farming.[Methods]The research was carried out in 3 test ponds and 3 control ponds.A 6 m×9 m×2.5 m cage was set every 667 m 2 in the test pond,and water circulator and microporous oxygenation equipment were installed.Ecological floating beds were set on both sides of the pond.Common aeration equipment was used for control ponds.The same number and size of crucian carp,and the same number,proportion and size of silver carp and bighead carp were raised in both the test and control groups.Total nitrogen,ammonium nitrogen,total phosphorus and phosphate content was determined every 15 d,and growth indicators and feed conversion ratios of fish were measured at the end of the experiment.[Conclusions]The content of total nitrogen,ammonium nitrogen,total phosphorus and phosphate in the experimental group decreased by 50.69%,69.12%,62.62%and 54.20%,respectively,compared with the control group.Compared with the control group,the harvest size,survival rate and yield per unit area of crucian carp in the experimental group increased by 5.25%,7.58%and 13.28%,respectively,and the feed conversion ratio decreased by 4.72%.[Results]The integrated agro-aquaculture model demonstrated significant advantages in mitigating eutrophication,improving yield,and enhancing feed efficiency.
基金supported by the Science and Technology Project of China South Power Grid Co.,Ltd.under Grant No.036000KK52222044(GDKJXM20222430).
文摘This paper addresses the complexity of wake control in large-scale wind farms by proposing a partitioning control algorithm utilizing the FLORIDyn(FLOW Redirection and Induction Dynamics)dynamic wake model.First,the impact of wakes on turbine effective wind speed is analyzed,leading to a quantitative method for assessing wake interactions.Based on these interactions,a partitioning method divides the wind farm into smaller,computationally manageable zones.Subsequently,a heuristic control algorithm is developed for yaw optimization within each partition,reducing the overall computational burden associated with multi-turbine optimization.The algorithm’s effectiveness is evaluated through case studies on 11-turbine and 28-turbine wind farms,demonstrating power generation increases of 9.78%and 1.78%,respectively,compared to baseline operation.The primary innovation lies in coupling the higher-fidelity dynamic FLORIDyn wake model with a graph-based partitioning strategy and a computationally efficient heuristic optimization,enabling scalable and accurate yaw control for large wind farms,overcoming limitations associated with simplified models or centralized optimization approaches.
基金the Science and Technology Fellowship Trust, Bangladesh
文摘Agriculture extension and advisory services(AEAS)are integral to smart agricultural systems and play a pivotal role in supporting sustainable agricultural development.The study aimed to assess the role of AEAS in strengthening climate-smart coastal farming system to enhance coastal agricultural sustainability.A mixed-methods study was conducted in the southwestern coastal region of Bangladesh in 2023,which involved administering a structured questionnaire and conducing face-to-face interviews with 390 farmers.Perceived role index(PRI)was employed to assess the potential role of AEAS.To forecast the perceived role outcomes,the machine learning model was undertaken by utilizing suitable algorithms.Additionally,feature importance was calculated to underpin the significant factors of perceived role outcomes.The findings showed that coastal farming communities held a comprehensive understanding of the role of AEAS.Key roles included diffusion of agricultural innovations,acting as a bridge between farmers and research organizations,using demonstration techniques to educate farmers,training farmers on food storage,processing,and utilization,and promoting awareness and adoption of best practices.The machine learning model exposed a significant relationship between farmers’socio-economic characteristics and their perception behavior.The results identified that factors like innovativeness,awareness,training exposure,access to AEAS,and access to information significantly influenced how farmers perceived the efficacy of AEAS in promoting a smart coastal farming system.However,farmers confronted multiple constraints in receiving demand-driven services and maintaining coastal farm sustainability.These insights can guide concerned authorities and policy-makers in providing AEAS for the purpose of strengthening climate-smart coastal farming system,particularly with a special focus on capacity building programs and machine learning application.Moreover,the outcomes of this study can assist the authorities of similar coastal systems throughout the world to initiate potential strategies for enhancing region-specific agricultural sustainability.
基金This work was conducted in the frame of the accompanying research on strategies for improving farmer families’incomes and sustainable cocoa production funded by the German Federal Ministry for Economic Cooperation and Development(BMZ).
文摘About 44%of the world’s cocoa is produced in one single country,Côte d’Ivoire.Providing this important raw material,most Ivorian cocoa farmers live in severe poverty,which,despite a multitude of sector interventions,is still widespread,affecting social and environmental sustainability in cocoa production.In this context,cocoa farmers are still often treated as a homogeneous group of small-scale producers(mainly males),resulting in interventions being conceptualized as one-size-fits-all approaches and failing to deliver support schemes that take farmers’specific conditions appropriately into account.Applying a broader typology approach that combines farm characteristics with farmers’characteristics,this study aims to delineate Ivorian cocoa farmers and their farms into specific types in order to improve advice for targeted sustainability interventions and living income(LI)potentials.Principal component analysis and hierarchical clustering analysis of a household dataset collected in 2022 in five cocoa-growing regions of Côte d’Ivoire were chosen to identify types of male-headed farms.To assure gender sensitive analysis,a female-headed farm type was created artificially.The specific characteristics of the identified types were captured using descriptive analysis.Descriptive statistics and non-parametric tests were then applied to examine the relationships between these farm types and various outcomes.Additionally,a binary logistic model was used to estimate the probability of these links in relation to variables relevant for achieving a LI.Finally,Spearman non-parametric correlation was used to identify eventual differences in the strength of relationships between key variables per farm type.Three different types of male-headed farms are identified:type 1(the most productive and diversified farms with larger size),type 2(middle-sized farms with strong focus on cash crops),and type 3(small-sized farms with a good level of diversification for self-consumption).The artificially created type 4 represents female-headed farms with the smallest size.On average,none of these farm types achieves a LI.However,type 1 shows the smallest LI gap,while type 4 is by far the worst.Our analyses reveal underlying socio-economic factors systematically disadvantaging female-headed cocoa farms,most notably limited access to land and other material assets.The key contribution of this study lies in the empirical identification of the different characteristics of farms in a given farming system,thereby identifying the need for targeted support interventions.Type-specific recommendations are made,showing pathways to provide tailored programs to farmers of different types in order to reduce their LI gaps.
基金supported by the Special Fund for Science and Technology Innovation Strategy of Guangdong Province,China(2022660500250009604)。
文摘Methane contributes to global warming,and livestock is one of the sources of methane production.However,methane emission studies using bibliometric tools in livestock are lacking.Given the negative impact of climate change on the ecosystem and the rise in methane emissions,it is essential to conduct a bibliometrics study to provide an overview and research trends.We used the Bibliometrix package and VOSviewer to decipher bibliometric indices for methane emissions in cattle farms(MECF).Current dataset were collected from the Web of Science(Core Collection)database,and 8,998 publications were analyzed.The most co-occurring keywords scientists preferred were methane(1,528),greenhouse gas(443),methane emissions(440),and cattle(369).Methane was the most frequently used keyword in the published scientific literature.Thematic evolution of research themes and trend results highlighted carbon dioxide,methane,dairy cattle,cattle,and risk factors during 1999–2017.Chinese Academy of Sciences ranked on top with 485 publications,followed by Agriculture&Agri-Food Canada,University of Colorado,National Oceanic and Atmospheric Administration,and Aarhus University.Chinese Academy of Sciences was also the most cited organization,followed by the University of Colorado,Agriculture&Agri-Food Canada,National Oceanic and Atmospheric Administration,and United States Geological Survey.Source analysis showed that the Science of the Total Environment was cited with the highest total link strength.Science of the Total Environment ranked first in source core 1 with 290 citation frequencies,followed by Journal of Dairy Science with 223 citation frequencies.Currently,no bibliometric study has been conducted on MECF,and to fill this knowledge gap,we carried out this study to highlight methane emissions in cattle farms,aiming at a climate change perspective.In this regard,we focused on the research productivity of countries authors,journals and institutions,co-occurrence of keywords,evolution of research trends,and collaborative networking.Based on relevance degree of centrality,methane emissions and greenhouse gases appeared as basic themes,cattle,and dairy cattle appeared as emerging/declining themes,whereas,methane,greenhouse gas and nitrous oxide appeared to fall amongst basic and motor themes.On the other hand,beef cattle,rumen and dairy cow seem to be between motor and niche themes,and risk factors lie in niche themes.The present bibliometric analysis provides research progress on methane emissions in cattle farms.Current findings may provide a framework for understanding research trends and themes in MECF research.
文摘In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. A five-step method and descriptive analysis were used on a sample of 250 farmers. The degree of damage caused by pests and crop diseases is significant, with respective proportions of 52.50% and 40.40%. It appears that the main climate risk factors for vulnerability are droughts, floods, soil degradation, and pest invasions. Additionally, the average level of exposure to agricultural operations is very high, with an index of 0.6. The sensitivity index remained constant in the range of 0.3 to 0.6 and is significant (reaching an index of 0.8). However, 61.2% of farms have a medium level of vulnerability and 33.3% have a high vulnerability to the effects of climate change. Nonetheless, a concerning trend regarding the vulnerability of farms has been observed. To assist policymakers and development actors in improving the vulnerability level of these production units, four phases of action are proposed: a diagnostic phase, evaluation, estimation of adaptation needs, implementation, and proper monitoring of actions.
文摘Climate change is becoming a major issue for agriculture and the well-being of farmers. The objective of this article is to identify and analyze the production factors that may influence the competitiveness level of agricultural operations, as well as to establish a structural and functional typology of these farms. Using Principal component analysis (PCA) combined with hierarchical ascending classification (HAC) on 250 farmers, the study was able to set farms typology. Furthermore, variance analysis and econometric models (linear et quadratic) were also used for in-depth analysis. The results show the existence of three groups of farm (GA, GB, GC): GA (19.7%), GB (65.3%), and GC (15%). Drought spells and flood are the main climatic risks affecting rain-fed farm operations. For irrigated crops such as rice, the major constraints remain bird attacks, the invasion of pests and nematodes. Climate variability significantly increases the prevalence of morbidities in the region by raising the number of inactive individuals. This significantly and differentially affects the outcomes of these assets. Health expenditures represent a significant share (GB: 12% and GC: 11%) and a non-negligible share (GA: 8.4%). However, larger participations (GC) show better economic performance due to economies of scale, but all categories would benefit from adopting appropriate strategies to reduce losses and increase their resilience.
文摘Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions varies significantly from one farmer to another, making it challenging to accurately estimate crop production through crop models. This limitation has implications for the reliability of using crop models as agricultural decision-making support tools. To support decision making in agriculture, an approach combining a genetic algorithm (GA) with the crop model AquaCrop is proposed for a location-specific calibration of maize cropping. In this approach, AquaCrop is used to simulate maize crop yield while the GA is used to derive optimal parameters set at grid cell resolution from various combinations of cultivar parameters and crop management in the process of crop and management options calibration. Statistics on pairwise simulated and observed yields indicate that the coefficient of determination varies from 0.20 to 0.65, with a yield deviation ranging from 8% to 36% across Burkina Faso (BF). An analysis of the optimal parameter sets shows that regardless of the climatic zone, a base temperature of 10˚C and an upper temperature of 32˚C is observed in at least 50% of grid cells. The growing season length and the harvest index vary significantly across BF, with the highest values found in the Soudanian zone and the lowest values in the Sahelian zone. Regarding management strategies, the fertility mean rate is approximately 35%, 39%, and 49% for the Sahelian, Soudano-sahelian, and Soudanian zones, respectively. The mean weed cover is around 36%, with the Sahelian and Soudano-sahelian zones showing the highest variability. The proposed approach can be an alternative to the conventional one-size-fits-all approach commonly used for regional crop modeling. Moreover, it has the potential to explore the performance of cropping strategies to adapt to changing climate conditions.
文摘The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is to analyze these impacts of climate disruption on the economic performance of farms. The methodology adopted for this study combined documentary research with field surveys conducted on a sample of 250 randomly selected farmers. The analytical methods used mainly consisted of linear regression, profitability calculations, and linear programming. The findings indicate that all productions across different crops have experienced a decrease over the past 30 years. For instance, the production of millet, sorghum, and cowpea, which were respectively 812 kg/ha, 260 kg/ha, and 100 kg/ha between the last 30 and 20 years, has now dropped to 412 kg/ha, 106 kg/ha, and 46 kg/ha respectively. A negative and significant effect on agricultural net margin was observed due to variables such as flooding, drought, pest invasion in rice fields, and temperature changes. Smallholder farms show a relatively low margin (46%) to cover their fixed costs, which may indicate a risk if fixed expenses are high. Furthermore, the analysis results from linear programming reveal that farmers could achieve an additional net profit per hectare of 116,861 FCFA, 217201.5 FCFA, and 291988.2 FCFA respectively for small, medium, and large producers by managing variable costs and health-related expenses for households.
文摘In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of the paper the artistic achievements of his masterpiece“The Lucky Purse”are explored.
基金supported by the National Natural Science Foundation of China under Grant 52077030.
文摘As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed in many wind farms.However,studies have shown that when the three-phase short-circuit fault occurs in the wind farm,the transient overcurrent during the fault occurrence and fault clearance is suppressed,making it difficult for GF-SVG to use traditional fixed virtual impedance.Aiming at the problem,firstly,the influence of virtual reactance on control stability is analyzed using the GF-SVG’s current open-loop transfer function.Secondly,based on the existing current limitation strategies of GF-SVG,an adaptive virtual reactance current limitation strategy suitable for symmetrical faults of the power grid is proposed,which limits GF-SVG’s transient overcurrent during fault occurrence and fault clearance stage to the tolerance range of GF-SVG’s power devices.Based on the GF-SVG’s active power loop and reactive power loop small signal models,the availability of the proposed adaptive virtual reactance in suppressing the DC voltage drop of GF-SVG is analyzed,and shortening the transient overvoltage recovery time of the wind farm after the fault clearance is also discussed.Finally,electromagnetic simulation proves the effectiveness and correctness of the proposed adaptive current limitation method.
基金supported by the European Union's Horizon 2020 Research and Innovation Programme under Grant No.774244(Breeding for resilient,efficient and sustainable organic vegetable productionBRESOV)by‘RGV-FAO'project funded by the Italian Ministry of Agriculture,Food Sovereignty and Forests。
文摘The increasing conversion of agricultural land to organic farming requires the development of specifically adapted cultivars.So far,in tomato there is lack of research for selection of germplasm suitable for sustainable agroecosystems.In this study,we investigated the genotypic and environmental factors affecting the variation of plant,fruits,and root traits in 39 tomato genotypes grown under organic farming conditions.Four independent experiments were conducted in Italy and Spain across two consecutive seasons in 2019 and 2020.For all traits,the factorial linear regression model to estimate the main effects of genotype(G),location(L),year of cultivation(Y)and their interactions,revealed highly significant(P<0.001)variations,with the G factor being largely predominant for most traits.The implementation of the“which-won-where”,“mean performance versus stability”and“discriminative vs representativeness”patterns in the GGE(Genotype plus Genotype by Environment interaction)analysis,allowed the identification of superior cultivars with high stability across the testing environments.Genomic characterization with 30890 high quality SNPs from dd RADseq genotyping analysis,revealed that a specific cluster of cherry tomato accessions were low performing in terms of yield and fruit weight,on the contrary,showed a high content of soluble solids,which in agreement with GGE analysis.Results of this study provide a framework for the potential use of this locally adapted tomato germplasm to address the needs of more sustainable agriculture.
文摘The rapid expansion of tobacco farming poses a significant threat to biodiversity in Yunnan Province,China,a region known for its rich biodiversity.This study aims to understand the trade-offs between tobacco farming and higher plant species diversity,and to identify priority counties for conservation.We employed an integrated approach combining species distribution modeling,GIS overlay analysis,and empirical spatial regression to em pirically assess the impact of tobacco farming intensity on biodiversity risk.Our findings reveal a compelling negative spatial correlation between tobacco farming expansion and higher plant species diversity.Specifically,southern counties in Wenshan and Honghe prefectures are major priority areas of conservation that exhibit signif icant spatial correlations between biodiversity risks and high tobacco farming intensity.Quantitatively,at county level,a 1%increase in tobacco farming area corresponds to a 0.094%decrease in endemic higher plant species richness across the entire province.These results underscore the need for targeted and region-specific regulations to mitigate biodiversity loss and promote sustainable development in Yunnan Province.The integrated approach used in this study provides a comprehensive assessment of the tobacco-biodiversity trade-offs,offering actionable insights for policymaking.
文摘Intensive farming practices,aimed at maximizing crop yields through substantial inputs of labour,technology,and chemical fertilizers,have significantly transformed modern agriculture.However,these methods have raised serious concerns regarding soil health,environmental sustainability,and long-term agricultural viability.This study examines the ecological impact of intensive farming on soil health in the KB Asifabad District of Telangana,India,where traditional and modern farming techniques coexist.The objectives include analysing socio-economic factors influencing farming methods,evaluating the impact of tilling techniques and fertilizer use on soil health,and promoting sustainable practices through education and policy recommendations.Findings reveal a strong reliance on chemical fertilizers,with 98.3% of farmers using them exclusively due to their perceived efficiency and rapid results.However,this overdependence has led to soil degradation,reduced microbial diversity,and environmental pollution.Conversely,despite its ecological benefits,natural manure remains underutilized due to scepticism and economic constraints.Mechanical tilling methods,while effective,have negatively impacted soil structure and fertility.The study highlights the necessity of transitioning to sustainable practices,integrating organic inputs,and adopting conservation techniques to restore soil health and ecosystem balance.This research provides practical pathways for achieving sustainable agriculture by integrating traditional knowledge with modern practices.It is particularly relevant for policymakers,agricultural extension services,and farming communities as it highlights the need for educational initiatives,financial incentives,and regulatory measures to ensure long-term soil fertility,environmental stewardship,and improved farmer livelihoods.
基金supported by the Natural Science Foundation of China(32302233,32472466)the Natural Science Foundation of Zhejiang(LZ24C200004)+6 种基金the Key Research and Development Program of Zhejiang Province(2022C02049)the Key Research and Development Program of Ningbo(2022Z178)the Ministry of Agriculture and Rural Affairs(20244027)the WalMart Foundation(UA2020-152,UA2021-247)the State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products(2021DG700024-KF202517)the Zhejiang Provincial Department of Agriculture and Rural Affairs Project(2024SNJF044)the Key Research and Development Program of Zhuji(2022J10).
文摘The contamination of pork during breeding can negatively impact both food quality and safety.Sodium dichloroiso-cyanurate(NaDCC),a chlorine-containing disinfectant,is widely used in animal environments.In this study,16S rRNA sequencing was used to determine the bacterial communities in a pork farm.We also assessed the effectiveness of NaDCC disinfection by analyzing microbial diversity.The results revealed that the predominant genera in pork skin samples and environmental samples were Staphylococcus and Acinetobacter,respectively.Escherichia coli and Strep-tococcus equinus were present in all the samples,suggesting that NaDCC is not fully effective in preventing zoonotic pathogen contamination.The Chao1 and Shannon indices for sow skins increased after disinfection.No significant differences were observed in the microbiological composition of sow barn samples before and after disinfection(p>0.1).Additionally,bacterial abundance in sow skin was strongly correlated with abundance on pen floors(r=0.906,p<0.05),indicating potential cross-contamination between these sample types.Conversely,the bacterial abun-dance in the floor samples was weakly correlated with that in the other samples,suggesting that NaDCC is effective as a decontaminant.This study provides valuable insights into microbial contamination on pork farms and under-scores the importance of proper disinfection practices.This study also offers scientific recommendations for improv-ing disinfection protocols.
基金Partial funding from the John Dove Isaacs Endowed Chair for Natural Philosophy in Engineering at UC San Diego。
文摘This work addresses challenges and opportunities in the evaluation of solar power plant impacts,with a particular focus on thermal effects of solar plants on the environment and vice-versa.Large-scale solar power plants are often sited in arid or desert habitats,which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity.Our understanding of both shortwave(solar)and longwave(terrestrial)radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications.In contrast to radiation,the convective environment in large-scale solar power plants is much more difficult to characterize.Wind direction,wind speed,turbulence intensity,dust concentration,ground condition,panel configuration density,orientation and distribution throughout the solar field,all affect the local environment,the balance between radiation and convection,and in turn,the performance and thermal impact of solar power plants.Because the temperatures of the two sides of photovoltaic(PV)panels depend on detailed convection-radiation balances,the uncertainty associated with convection affects the heat and mass transfer balances as well.Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats.Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions.
基金funded by the Science and Technology Project of State Grid Corporation,grant number 5500-202329500A-3-2-ZN,funding data 2023.10–2025.12.
文摘Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control method for its active-loop parameters is used to realize thewind-farmfrequency support,which has become the current research hotspot.Taking the ESVG with a supercapacitor on the DC side as the research object,the influence trend of the change of virtual rotation inertia and virtual damping coefficient on its virtual angular velocity and power angle is analyzed.Then,the constraint relationship between the equivalent virtual inertia time constant of the supercapacitor and the virtual rotation inertia of the ESVG is clarified.Then,combined with the second-order response characteristics of the ESVG power control loop,the selection principles of the frequency modulation coefficient,the virtual rotation inertia,and the virtual damping coefficient are determined.An ESVG adjustment control method,considering the adaptive adjustment of the active loop parameters of the supercapacitor equivalent inertia,is proposed.While ensuring the frequency support capability of the ESVG,the fluctuation degree of its output active power and the virtual angular velocity are suppressed,and the proposed adjustment method also improves the stability of the ESVG control system and the frequency support capability for the wind farm.Finally,the simulation verifies the correctness of the theoretical analysis and the effectiveness of the proposed strategy.
基金Supported by New Era Vocational School famous teachers and Principals Training Program of Hubei ProvinceAction Plan for Science and Technology Support in Rural Revitalization of Higher Education Institutions of Department of Education of Hubei Province(BXLBX1376)Horizontal Project of Animal Epidemic Diagnosis Technology Research and Product Development.
文摘[Objectives]This study was conducted to evaluate the practical efficacy of Haemophilus parasuis(Hps)vaccines and determine whether the continuous use of vaccines leads to changes in Hps serotypes.[Methods]A swine production group that had used a bivalent vaccine of Hps serotypes 4 and 5 for two consecutive years were investigated and retrospectively analyzed.Data on Hps detection rate,nursery production and disease indexes,as well as serotype shifts after continuous vaccination,were collected to assess vaccine effectiveness.[Results]Continuous vaccination reduced the total nursery culling and mortality rate by 1.75%.Hps infection persisted in the farms,and the pathogen could still be isolated.However,serotyping revealed a significant shift in the dominant prevalent serotypes,indicating that the vaccine was indeed effective.[Conclusions]The matched Hps vaccine demonstrated effective results.However,whether replacing serotypes or adding more prevalent serotypes could further improve the control of Hps disease requires further investigation.
基金funded by King Fahd University of Petroleum&Minerals,Saudi Arabia under IRC-SES grant#INRE 2217.
文摘Wind energy has emerged as a potential replacement for fossil fuel-based energy sources.To harness maximum wind energy,a crucial decision in the development of an efficient wind farm is the optimal layout design.This layout defines the specific locations of the turbines within the wind farm.The process of finding the optimal locations of turbines,in the presence of various technical and technological constraints,makes the wind farm layout design problem a complex optimization problem.This problem has traditionally been solved with nature-inspired algorithms with promising results.The performance and convergence of nature-inspired algorithms depend on several parameters,among which the algorithm termination criterion plays a crucial role.Timely convergence is an important aspect of efficient algorithm design because an inefficient algorithm results in wasted computational resources,unwarranted electricity consumption,and hardware stress.This study provides an in-depth analysis of several termination criteria while using the genetic algorithm as a test bench,with its application to the wind farm layout design problem while considering various wind scenarios.The performance of six termination criteria is empirically evaluated with respect to the quality of solutions produced and the execution time involved.Due to the conflicting nature of these two attributes,fuzzy logic-based multi-attribute decision-making is employed in the decision process.Results for the fuzzy decision approach indicate that among the various criteria tested,the criterion Phi achieves an improvement in the range of 2.44%to 32.93%for wind scenario 1.For scenario 2,Best-worst termination criterion performed well compared to the other criteria evaluated,with an improvement in the range of 1.2%to 9.64%.For scenario 3,Hitting bound was the best performer with an improvement of 1.16%to 20.93%.
基金funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2025-30)The Science and Technology Fellowship Trust(SL No.39.00.0000.035.22.013.19.144)under the Ministry of Science and Technology of Bangladesh partially financed the current research。
文摘Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.
