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Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems 被引量:1
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作者 Francis Levi A.DURANO Jon Marx SARMIENTO +1 位作者 Larry N.DIGAL Pedro A.ALVIOLA IV 《Journal of Mountain Science》 SCIE CSCD 2024年第1期33-48,共16页
Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa ... Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas. 展开更多
关键词 Cocoa farms Cobb-Douglas production function ELEVATION Philippines Stochastic frontier analysis Technical efficiency
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Productivity and technical efficiency of Robusta coffee farms at varying elevation categories in Sultan Kudarat, Philippines: implications on sustainability
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作者 Mark James S.SAGUIMPA Larry N.DIGAL 《Journal of Mountain Science》 SCIE CSCD 2024年第11期3615-3629,共15页
Elevation can affect agricultural outputs,affecting farms’productivity and efficiency.This article identified the significant production inputs influencing productivity and factors influencing technical efficiency(TE... Elevation can affect agricultural outputs,affecting farms’productivity and efficiency.This article identified the significant production inputs influencing productivity and factors influencing technical efficiency(TE)and determined the average TE scores of Robusta coffee farms at varying elevations in Sultan Kudarat,Philippines.Cross-sectional data from the Mahintana Foundation,Inc.using random stratified sampling and power analysis from September 9,2021,to January 13,2022,were used to analyze 604 farms from areas ranging from 0.33 to 1284.18 above mean sea level(amsl),classified as low,medium,and high elevation.Open-Data-Kit-based(ODK)mobile data collection systems were utilized to precisely determine the farms’coordinates and elevation.Using stochastic frontier analysis,results showed that increasing the total fertilizer amount and total trees by 1%significantly increased yield by 0.20%and 0.79%,respectively.Meanwhile,increasing the total land area by 1%,including areas unutilized for coffee farming,decreases total yield by 0.11%.Regarding TE,results showed that TE decreases by approximately 0.58%at high elevations.Meanwhile,increasing net income from coffee farming alone by 1%significantly increases TE by 0.00008%.With an average TE of 0.60,0.77,and 0.63 in low,medium,and high elevations,farms may be incentivized to improve farming practices to increase their TE further.TE improvement recommendations include promoting coffee-agroforestry systems and ecolabelling at medium elevations,such as shade-grown coffee,to promote sustainable production in Robusta coffee farms by assigning a premium to consumers demanding environmental conservation. 展开更多
关键词 Cobb-Douglas production function ELEVATION Philippines Robusta coffee farms Stochastic frontier analysis Technical efficiency
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Identification of Microorganisms in Poultry Farms in N’djamena and the Border Areas of Hadjer-Lamis and Chari-Baguirmi Chad
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作者 Abakar Abbo Zakaria Bebanto Antipas Ban-Bo +2 位作者 Nadine Terei Bongo Naré Richard Gandolo Abdelsalam Adoum Doutoum 《Journal of Agricultural Chemistry and Environment》 2024年第2期223-234,共12页
Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real... Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real health problems attributable to a lack of monitoring of the vaccination schedule, inadequate compliance with biosecurity measures and poor application of the Ichikawa rule based on the 5 M’s. Objective: The aim of this article is to identify the microorganisms responsible for contamination of poultry farms in the study area. Method: The study was carried out from 28/04/2022 to 31/01/2023 on the basis of 300 samples taken from feed, drinking water, droppings and scrapings from poultry housing surfaces in the 30 farms that served as a framework for our research. Sampling was of the simple random type, and farms were selected on the basis of the farmers’ consent. The data were recorded on pre-established survey forms. Our study was cross-sectional, descriptive and prospective. Bacteria were isolated using the reference method NF EN ISO 6579 for Salmonella spp. and cultured on the specific medium eosin methylene blue (EMB) for Escherichia coli, Pseudomonas and Citrobacter freundii. Results: The following results emerged from this study: Escherichia coli (5.33%), Pseudomonas (1.33%), Citrobacter freundii (12%) and Salmonella paratyphi (21.68%). Conclusion: Of the 300 samples analysed, 121 (40.33%) were contaminated with pathogens. This high level of contamination is a health problem. The study shows that biosecurity is less satisfactory on the farms visited. Nevertheless, farms with a very satisfactory level of biosafety ensure food safety and variety for the population. 展开更多
关键词 Microorganisms Identification Poultry farms N’Djamena Hadjer-Lamis Chari-Baguirmi(Chad)
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Wind farms increase land surface temperature and reduce vegetation productivity in the Inner Mongolia
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作者 Luyao Liu Pengtao Liu +3 位作者 Jiawei Yu Gang Feng Qing Zhang Jens-Christian Svenning 《Geography and Sustainability》 CSCD 2024年第3期319-328,共10页
Wind power has been developing rapidly as a key measure to mitigate human-driven global warming.The under-standing of the development and impacts of wind farms on local climate and vegetation is of great importance fo... Wind power has been developing rapidly as a key measure to mitigate human-driven global warming.The under-standing of the development and impacts of wind farms on local climate and vegetation is of great importance for their rational use but is still limited.In this study,we combined remote sensing and on-site investigations to identify wind farm locations in Inner Mongolia and performed landscape pattern analyses using Fragstats.We explored the impacts of wind farms on land surface temperature(LST)and vegetation net primary productivity(NPP)between 1990 and 2020 by contrasting these metrics in wind farms with those in non-wind farm areas.The results showed that the area of wind farms increased rapidly from 1.2 km2 in 1990 to 10,755 km2 in 2020.Spatially,wind farms are mainly clustered in three aggregation areas in the center.Further,wind farms increased nighttime LST,with a mean value of 0.23℃,but had minor impacts on the daytime LST.Moreover,wind farms caused a decline in NPP,especially over forest areas,with an average reduction of 12.37 GC/m^(2).Given the impact of wind farms on LST and NPP,we suggest that the development of wind farms should fully consider their direct and potential impacts.This study provides scientific guidance on the spatial pattern of future wind farms. 展开更多
关键词 Wind farm Landscape pattern LST NPP Inner Mongolia
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Mobile genetic elements facilitate the transmission of antibiotic resistance genes in multidrug-resistant Enterobacteriaceae from duck farms
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作者 Xin’er Zheng Dingting Xu +5 位作者 Jinchang Yan Min Qian Peng Wang Davood Zaeim Jianzhong Han Daofeng Qu 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期729-735,共7页
Multidrug-resistant(MDR)Enterobacteriaceae critically threaten duck farming and public health.The phenotypes,genotypes,and associated mobile genetic elements(MGEs)of MDR Enterobacteriaceae isolated from 6 duck farms i... Multidrug-resistant(MDR)Enterobacteriaceae critically threaten duck farming and public health.The phenotypes,genotypes,and associated mobile genetic elements(MGEs)of MDR Enterobacteriaceae isolated from 6 duck farms in Zhejiang Province,China,were investigated.A total of 215 isolates were identified as Escherichia coli(64.65%),Klebsiella pneumoniae(12.09%),Proteus mirabilis(10.23%),Salmonella(8.84%),and Enterobacter cloacae(4.19%).Meanwhile,all isolates were resistant to at least two antibiotics.Most isolates carried tet(A)(85.12%),blaTEM(78.60%)and sul1(67.44%)resistance genes.Gene co-occurrence analysis showed that the resistance genes were associated with IS26 and integrons.A conjugative IncFII plasmid pSDM004 containing all the above MGEs was detected in Proteus mirabilis isolate SDM004.This isolate was resistant to 18 antibiotics and carried the blaNDM-5 gene.MGEs,especially plasmids,are the primary antibiotic resistance gene transmission route in duck farms.These findings provide a theoretical basis for the rational use of antibiotics in farms which are substantial for evaluating public health and food safety. 展开更多
关键词 Duck farm Mobile genetic element Antibiotic resistance gene PLASMID Food safety
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语篇分析视角下的美国Bolthouse Farms公司的饮料广告
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作者 林如心 《科教文汇》 2014年第22期160-161,共2页
美国Bolthouse Farms公司的饮料在美国广受欢迎,可以说,饮料是Bolthouse Farms公司的一个成功。本文从语篇分析的角度对Bolthouse Farms公司的饮料广告进行分析,指出该公司饮料产品的成功离不开其广告的独特的语篇特征。
关键词 语篇分析 Bolthouse farms饮料 广告
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Construction of Risk Assessment Application Model of Epidemic Disease in Large-scale Pig Farms 被引量:1
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作者 谭业平 刘强 +3 位作者 胡肄农 郁达威 何孔旺 陆昌华 《Agricultural Science & Technology》 CAS 2016年第9期2124-2126,共3页
The application model of epidemic disease assessment technology for Web-based large-scale pig farm was expounded from the identification of epidemic disease risk factors, construction of risk assessment model and deve... The application model of epidemic disease assessment technology for Web-based large-scale pig farm was expounded from the identification of epidemic disease risk factors, construction of risk assessment model and development of risk assessment system. The assessed pig farm uploaded the epidemic disease risk data information through on-line answering evaluating questionnaire to get the immediate evaluation report. The model could enhance the risk communication between pig farm veterinarian, manager and veterinary experts to help farm system understand and find disease risk factors, assess and report the potential high risk items of the pig farm in the three systems of engineering epidemic disease prevention technology, biological safety and immune monitoring, and promote the improvement and perfection of epidemic disease prevention and control measures. 展开更多
关键词 Large-scale pig farm Risk assessment of epidemic disease Model construction
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The short-and long-term impacts of the COVID-19 pandemic on family farms in China-Evidence from a survey of 2324 farms 被引量:3
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作者 DU Zhi-xiong LAI Xiao-dong +1 位作者 LONG Wen-jin GAO Liang-liang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第12期2877-2890,共14页
Family farms are considered the most desirable form of Chinese agriculture.Studies on the risk management of family farms are rare,while the COVID-19 pandemic provides an opportunity to explore how family farms respon... Family farms are considered the most desirable form of Chinese agriculture.Studies on the risk management of family farms are rare,while the COVID-19 pandemic provides an opportunity to explore how family farms respond to risks.Based on an online survey of 2324 family crop farms,we examine for the first time the short-term impact(immediate impact or short-term fluctuation,and farms’instantaneous response)and long-term impact(on farms’future or long-term production)of the COVID-19 pandemic on family farms’production and operation in rural China.By using factor analysis and dummy variable regression,we find that the severity of the pandemic,the lockdown of the village,and farmers’knowledge of the pandemic contribute significantly to the short-term impact,but not on the long-term impact.Farmers’characteristics such as gender,age,and education are not related to the short-term impact,but family farms with male owners or owners with high school education or below are more likely to be diversified and large-scale.The number of years the farm has existed for and agricultural insurance affect both short-term and long-term impacts.We suggest that the government needs to pay more attention to stability-enhancing policies,the market environment,vocational training and the agricultural insurance market. 展开更多
关键词 family farms COVID-19 agricultural risk China
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Two-stage ADMM-based distributed optimal reactive power control method for wind farms considering wake effects 被引量:3
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作者 Zhenming Li Zhao Xu +2 位作者 Yawen Xie Donglian Qi Jianliang Zhang 《Global Energy Interconnection》 EI CAS CSCD 2021年第3期251-260,共10页
Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption o... Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption of wind generators.In this study,a two-stage reactive power optimization method based on the alternating direction method of multipliers(ADMM)algorithm is proposed for achieving optimal reactive power dispatch in wind farm-integrated distribution systems.Unlike existing optimal reactive power control methods,the proposed method enables distributed reactive power flow optimization with a two-stage optimization structure.Furthermore,under the partition concept,the consensus protocol is not needed to solve the optimization problems.In this method,the influence of the wake effect of each wind turbine is also considered in the control design.Simulation results for a mid-voltage distribution system based on MATLAB verified the effectiveness of the proposed method. 展开更多
关键词 Two-stage optimization Reactive power optimization Grid-connected wind farms Alternating direction method of multipliers(ADMM)
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Planning Evaluation on Spatial Layout of Livestock and Poultry Farms 被引量:2
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作者 YAN Bo-jie WU Wen-ying +1 位作者 PAN Yu-chuan ZHANG Yong-ping 《Animal Husbandry and Feed Science》 CAS 2009年第11期37-41,46,共6页
The problems of spatial layout in livestock and poultry farms were discussed, and the development status of the planning evaluation on the spatial layout in recent years was systematically reviewed. The research progr... The problems of spatial layout in livestock and poultry farms were discussed, and the development status of the planning evaluation on the spatial layout in recent years was systematically reviewed. The research progress in planning evaluation systems and methods was mainly intro- duced. And some opinions were proposed to solve these problems. 展开更多
关键词 Livestock and poultry farms Spatial layout Planning evaluation Evaluation indicators
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Empirical Study on Formation Path of Family Farms in Different Environments from the Perspective of ANT 被引量:2
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作者 Yanchun CHEN Suisheng ZHAO +2 位作者 Gong CHENG Huiwen SHANG Yongke ZHAO 《Asian Agricultural Research》 2015年第6期6-12,共7页
Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern a... Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern agricultural management. With ANT as theoretical basis,this paper analyzed formation of family farms in the joint action of endogenous and exogenous forces. Besides,it analyzed Fengsheng Tobacco Family Farm of Guyue Town in Zhucheng City of Shandong Province and Li Chunfeng's Family Farm in Songjiang District of Shanghai.Research indicates that different regional environments bring about different actors and also different formation paths for family farms. 展开更多
关键词 FAMILY farms FORMATION PATH Actor-Network-Theory(A
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Impact of Wind Farms of DFIG Type on Power System Transient Stability 被引量:2
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作者 Libao Shi Shiqiang Dai +2 位作者 Liangzhong Yao Yixin Ni Masoud Bazargan 《Journal of Electromagnetic Analysis and Applications》 2010年第8期475-481,共7页
The impact of large-scale grid-connected wind farms of Doubly-fed Induction Generator (DFIG) type on power system transient stability is elaborately discussed in this paper. In accordance with an equivalent generator/... The impact of large-scale grid-connected wind farms of Doubly-fed Induction Generator (DFIG) type on power system transient stability is elaborately discussed in this paper. In accordance with an equivalent generator/converter model, the comprehensive numerical simulations with multiple wind farms of DFIG type involved are carried out to reveal the impact of wind farm on dynamic behavior of existing interconnected power system. Different load models involving nonlinear load model and induction motor model are considered during simulations. Finally, some preliminary conclusions are summarized and discussed. 展开更多
关键词 TRANSIENT Stability DFIG Multiple WIND farms WIND FARM Integration LOAD Model
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Problems of Family Farms in China and Countermeasures 被引量:1
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作者 Huamei LIN Houjun WANG 《Asian Agricultural Research》 2014年第6期12-15,共4页
In the Communiqué of the Third Plenary Session of the 18 th Central Committee of the CPC,it proposed the tasks of accelerating the building of a new type of agricultural operation system,endowing farmers with mor... In the Communiqué of the Third Plenary Session of the 18 th Central Committee of the CPC,it proposed the tasks of accelerating the building of a new type of agricultural operation system,endowing farmers with more property rights,promoting equal exchanges of factors of production and balanced allocation of public resources between urban and rural areas,and improving the institutions and mechanisms for promoting the sound development of urbanization. However,as new agricultural operating entities,family farms have problems of land circulation,lack of scientific and technological talents,and backward infrastructure. In line with these problems,this study put forward recommendations and countermeasures,in the hope of promoting increase in farmers' income,increasing agricultural intensification and large-scale level,and realizing agricultural modernization. 展开更多
关键词 FAMILY farms New AGRICULTURAL operating entities P
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Evaluation of Levels of Selected Heavy Metals in Kales, Soils and Water Collected from Irrigated Farms along River Moiben, Uasin-Gishu County, Kenya 被引量:1
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作者 Teresa Akenga Kiplagat Ayabei +2 位作者 Emmy Kerich Vincent Sudoi Cyrus Kuya 《Journal of Geoscience and Environment Protection》 2020年第2期144-155,共12页
There has been a rapidly increasing urbanization and industrialization as well as increased usage of agrochemicals in the recent few years which have resulted in accumulation of heavy metals in cultivated food, soils ... There has been a rapidly increasing urbanization and industrialization as well as increased usage of agrochemicals in the recent few years which have resulted in accumulation of heavy metals in cultivated food, soils and water. This research aimed at establishing the levels of Zn2+, Cd2+, Cu2+, Cr2+, Mn2+, Fe2+ and Pb2+ metal ions in kales, soil and irrigation water on farms along river Moiben. Twenty seven samples of vegetables, soil and water samples were collected using purposive sampling method, that is, the samples were collected from the households who had kales in their farms. Samples were then dried, grounded, digested and analyzed using Inductive Couple Plasma-Optical Emission Spectroscopy (ICP-OES). The results showed that the Fe had the highest mean in soil and water with the values of 250.22 ± 85.37 and 0.72 ± 0.33 mg/kg respectively, while in kales Zn value was highest with a value of 0.0154 ± 0.007 mg/kg. The metal ion concentrations in the soils and the irrigation water were higher than in kales. The concentrations on the metal ions were following this order Fe > Mn > Zn > Cu > Cr > Pb > Cd for soil as well as for water but for the kales sample it followed slightly different order Zn > Fe > Mn > Cu > Cr > Pb > Cd. In soil samples, metal ions concentrations (mg/kg) were found to be high compared to the levels in water and kales. ANOVA tests revealed that the mean difference in heavy metals concentration from different stations within the area was insignificant (p > 0.05) with an exception of Cd (p = 0.001) in water samples, Fe (p = 0.007) in kales samples, Zn (p = 0.016) and Cd (p = 0.011) in the samples of soil. Results were compared to the acceptable levels set by World Health Organization (WHO) and the study showed that for kales, concentrations of the metal ions were all lower than the (WHO) set standards. For water samples, Fe, Pb, Mn metal ions were above the WHO set standards. The presence of the investigated heavy metals in the samples could be pointed to excessive use of agrochemicals as indicated by our earlier survey on the use of agrochemicals. We therefore recommend thorough investigations and monitoring of the said heavy metals in the commercially distributed agrochemicals. 展开更多
关键词 HEAVY Metals Kales SOILS and WATER IRRIGATED farms
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Thoughts on Development of Green Agriculture and Green Economy——Based on the Survey of Farms in Qinhuangdao 被引量:1
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作者 Rongjia LIU Bing YE Di ZHANG 《Asian Agricultural Research》 2017年第11期1-4,共4页
Based on the concept and development process of green agriculture and green economy,the field survey and questionnaire investigation were carried out in Jincheng Specialized Planting Cooperative in Xinji Town,Changli ... Based on the concept and development process of green agriculture and green economy,the field survey and questionnaire investigation were carried out in Jincheng Specialized Planting Cooperative in Xinji Town,Changli County of Qinhuangdao City. The results show that there are still many problems in the development of green economy and the improvement of green farms in Hebei Province. On this basis,it came up with pertinent measures and recommendations,in the hope of providing theoretical basis and reference for establishment and development of green farms in Hebei Province and most of domestic areas. 展开更多
关键词 Green economy Green agriculture Diversified green farms Sustainable development
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Special report on relationship between wind farms and power grids 被引量:1
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作者 Dai Huizhu Wang Weisheng Li Hanxiang 《Engineering Sciences》 EI 2009年第2期13-17,共5页
The installed capacity of a large scale wind power plant will be up to a number of hundreds MW, and the wind power is transmitted to load centers through long distance transmission lines with 220 kV, 500 kV, or 750 kV... The installed capacity of a large scale wind power plant will be up to a number of hundreds MW, and the wind power is transmitted to load centers through long distance transmission lines with 220 kV, 500 kV, or 750 kV. Therefore, it is necessary not only considering the power transmission line between a wind power plant and the first connection node of the power network, but also the power network among the group of those wind power plants in a wind power base, the integration network from the base to the existed grids, as well as the distribution and consumption of the wind power generation by loads. Meanwhile, the impact of wind power stochastic fluctuation on power systems must be studied. In recent years, wind power prediction technology has been studied by the utilities and wind power plants. As a matter of fact, some European countries have used this prediction technology as a tool in national power dispatch centers and wind power companies. 展开更多
关键词 wind farms (wind power plants) power grids wind power integration wind power prediction
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Current Situation and Prospect Analysis of Biogas Project in Scale Farms in Chengdu
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作者 孙家宾 彭朝晖 +2 位作者 樊战辉 胡启春 朱顺熙 《Agricultural Science & Technology》 CAS 2017年第12期2430-2434,共5页
In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breedi... In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breeding scale and the demand space for biogas project were analyzed according to the changes in farm scale and farm quantity, the present situation of livestock breeding, the biogas technical pattern and present project quantity in Chengdu. Furthermore, based on the cultivated land area in Chengdu, a principle that "land decides production, pro- duction decides fertilizer, and fertilizer decides livestock" was proposed, and a pro- gram for the livestock quantity and biogas projects in Chengdu in "The 13th Five- Year" was suggested. Suggestions were also made for government to modify the allowance standards for biogas project construction. 展开更多
关键词 Chengdu Scale farm "Biogas project ANALYSIS
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Major Causes of Calf Morbidity and Mortality in Smallholder Dairy Farms in Shashemene Town,Ethiopia 被引量:2
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作者 Abdela Edao Abdurahman Meribo 《NASS Journal of Agricultural Sciences》 2021年第2期51-57,共7页
A cross-sectional study was conducted to determine the major causes of calf morbidity and mortality in smallholder dairy farms and associated potential risk factors in Shashemene.A total of 187 calves from 46 farms we... A cross-sectional study was conducted to determine the major causes of calf morbidity and mortality in smallholder dairy farms and associated potential risk factors in Shashemene.A total of 187 calves from 46 farms were included in the present study.The overall crude morbidity and crude mortality rates were 27.8%and 6.4%,respectively.The most frequent by pneumonia 8(4.3%),Gastrointestinal tract(GIT)disorder 8(4.3%)and septicemia 5(2.7%).In addition skin lesion,navel ill and unidentified cases were encountered.The main causes of death were diarrhea 6(3.2%),Septicemia 2(1.1%),GIT disorder 2(1.1%),pneumonia 1(0.5%)and others 1(0.5%).The most important risk factors associated with morbidity and mortality were housing hygiene,floor condition and calf size in farm.Out of 187 calves examined for GIT parasites;63(33.3%)were positive for nematode eggs.Prevalence of helminthes parasite increased with increasing age,showing higher prevalence(P<0.05)in calves above 2 months than in calves below 2 months of age.Besides,majority of the calves,48(25.7%)were found positive for coccidian oocyst.In general;diarrhea,pneumonia and septicemia were the major causes of calf morbidity and mortality.Interms of risk factors housing hygiene,floor condition,calf size in the farms,age and breed were identified major role players.Therefore,identifying major causes and improving management practices and breed should be given to emphasis by advisory of smallholder dairy farms. 展开更多
关键词 MORBIDITY Mortality SMALLHOLDER DAIRY farms Shashemene
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Pollution characteristics and risk assessment of organophosphate esters in aquaculture farms and natural water bodies adjacent to the Huanghe River delta
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作者 Jinyu CHAO Song FENG +2 位作者 Yingdong HAO Jianing LIN Bin ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期251-266,共16页
To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture c... To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture centers in China,where ecological security protection is crucial in the national strategy of China.To explore the pollution characteristics,bioaccumulation,and health risks of OPEs in aquaculture farms in the Huanghe River delta and natural water bodies in the adjacent seas,five species of organisms from different farm types nearby the Huanghe River delta,and the corresponding culture water and sediments were sampled in this study.The total concentrations of Σ_(13)OPEs in water,sediments,and organisms were 51.53-272.18 ng/L,52.63-63.17 ng/g dry weight(dw),and 46.82-108.90 ng/g dw,respectively.Among the five types of culture ponds,the water samples from the swimming crab and hairy crab culture ponds exhibited higher OPEs,the concentration of OPEs in the sediments from the few ponds was relatively balanced,and the OPEs in the organism from the holothurian ponds was higher.Tris(1,3-dichloro-2-isopropyl pho sphate)(TDCP)was the main contaminant in water samples and tripropyl phosphate(TPrP)in sediments and organisms.However,trisphenyl phosphate(TPhP)showed the strongest bioaccumulation ability,followed by 2-ethylhexyl diphenyl phosphate(EHDPP)and TPrP.The bioaccumulation capacities of the five species were as follows:prawn>holothurian>hairy crab>swimming crab>carp.These five types of organisms,as main seafood in human consumption,were at low risk of negative impacts of pollution.However,the risk from the mixture of organophosphate flame retardants(OPFRs)still requires more attention due to the increasing consumption and production in the world. 展开更多
关键词 organophosphate esters(OPEs) aquaculture farms BIOACCUMULATION health risk assessment
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Grid Integration of Wind Generation Considering Remote Wind Farms:Hybrid Markovian and Interval Unit Commitment
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作者 Bing Yan Haipei Fan +5 位作者 Peter B.Luh Khosrow Moslehi Xiaoming Feng Chien Ning Yu Mikhail A.Bragin Yaowen Yu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期205-215,共11页
Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment... Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment and economic dispatch problem where power generation of conventional units is linked to local wind states to dampen the effects of wind uncertainties.Also,to reduce complexity,extreme and expected states are considered as interval modeling.Although this approach is effective,the fact that major wind farms are often located in remote locations and not accompanied by conventional units leads to conservative results.Furthermore,weights of extreme and expected states in the objective function are difficult to tune,resulting in significant differences between optimization and simulation costs.In this paper,each remote wind farm is paired with a conventional unit to dampen the effects of wind uncertainties without using expensive utility-scaled battery storage,and extra constraints are innovatively established to model pairing.Additionally,proper weights are derived through a novel quadratic fit of cost functions.The problem is solved by using a creative integration of our recent surrogate Lagrangian relaxation and branch-and-cut.Results demonstrate modeling accuracy,computational efficiency,and significant reduction of conservativeness of the previous approach. 展开更多
关键词 BRANCH-AND-CUT interval optimization Markov decision process remote wind farms surrogate Lagrangian relaxation(SLR) unit commitment
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