Traditional environmental control methods for poultry housing which rely solely on environmental factors fall short in meeting thermal and physiological needs of the animals.New methods are needed that factor in the p...Traditional environmental control methods for poultry housing which rely solely on environmental factors fall short in meeting thermal and physiological needs of the animals.New methods are needed that factor in the physiological needs and responses of the animals in order to maximize well-being of the animals and minimize heat stress.Deep body temperature(DBT)has been shown in the literature to be a strong indicator of heat stress,therefore studies are needed that help us gain a deeper understanding of the relationship between this variable and environmental conditions.The aim of this study was to identify the order of the dynamic response of poultry DBT to large step changes in ambient temperature(AT).Temperature steps had to be big enough to take the chickens out of their homeothermic zone.A total of 46 DBT/AT data sets with 23 upward AT steps and 23 downward AT steps were obtained using a biotelemetry system,and involving three chickens.DBT responses of individual chickens to step changes in AT were found to have a 0.88 average Pearson correlation suggesting consistency in chickens’responses to the same stimuli(p<0.0005).The data indicated that DBT responses to AT followed a first order behavior in most cases with an average time constant of 1.6 h,and the curve fitting method was used to validate this observation.There was a 0.88 average correlation between DBT model and measured data(p<0.0005).These results indicate statistical significance in the data used and the model derived from it.In conclusion,it is reasonable to assume that the dynamic response of poultry DBT to large step changes in ambient temperature follows a first order model.Although further studies are needed to more fully derive the model,this study provided a stepping-stone towards gaining a better understanding of the relationship between DBT and AT,therefore taking us one step closer towards making optimal management and risk assessment decisions that are based on physiological needs of the chickens.展开更多
提出了一套可控串联电容补偿TCSC(Thyristor Controlled Series Compensation)动态模拟装置的设计方案。装置分为控制保护、录波和远程监控3个单元,每个单元中的插件都是一个完成单一任务的功能模块,各功能模块均是由双口RAM交换接口进...提出了一套可控串联电容补偿TCSC(Thyristor Controlled Series Compensation)动态模拟装置的设计方案。装置分为控制保护、录波和远程监控3个单元,每个单元中的插件都是一个完成单一任务的功能模块,各功能模块均是由双口RAM交换接口进行数据交换,通过工控机的ISA总线相连组成一个整体,采用这种硬件结构装置的实时性、可靠性和扩展性得到了极大的提高;控制保护单元和录波单元通过集线器与远程监控单元相连,同时控制保护单元和录波单元也有各自的监控界面,方便进行就地调试和监控。装置采用分层设计,中上层控制策略用C语言编程实现,易于进行各种控制策略和保护的研究。利用所研制的实验装置,分别在电容电压同步方式和线路电流同步方式下,进行了TCSC的基频阻抗特性实验。实验结果表明,该TCSC实验装置能够快速调节阻抗,并能灵活地完成不同阻抗模式之间的切换。展开更多
文摘Traditional environmental control methods for poultry housing which rely solely on environmental factors fall short in meeting thermal and physiological needs of the animals.New methods are needed that factor in the physiological needs and responses of the animals in order to maximize well-being of the animals and minimize heat stress.Deep body temperature(DBT)has been shown in the literature to be a strong indicator of heat stress,therefore studies are needed that help us gain a deeper understanding of the relationship between this variable and environmental conditions.The aim of this study was to identify the order of the dynamic response of poultry DBT to large step changes in ambient temperature(AT).Temperature steps had to be big enough to take the chickens out of their homeothermic zone.A total of 46 DBT/AT data sets with 23 upward AT steps and 23 downward AT steps were obtained using a biotelemetry system,and involving three chickens.DBT responses of individual chickens to step changes in AT were found to have a 0.88 average Pearson correlation suggesting consistency in chickens’responses to the same stimuli(p<0.0005).The data indicated that DBT responses to AT followed a first order behavior in most cases with an average time constant of 1.6 h,and the curve fitting method was used to validate this observation.There was a 0.88 average correlation between DBT model and measured data(p<0.0005).These results indicate statistical significance in the data used and the model derived from it.In conclusion,it is reasonable to assume that the dynamic response of poultry DBT to large step changes in ambient temperature follows a first order model.Although further studies are needed to more fully derive the model,this study provided a stepping-stone towards gaining a better understanding of the relationship between DBT and AT,therefore taking us one step closer towards making optimal management and risk assessment decisions that are based on physiological needs of the chickens.
文摘提出了一套可控串联电容补偿TCSC(Thyristor Controlled Series Compensation)动态模拟装置的设计方案。装置分为控制保护、录波和远程监控3个单元,每个单元中的插件都是一个完成单一任务的功能模块,各功能模块均是由双口RAM交换接口进行数据交换,通过工控机的ISA总线相连组成一个整体,采用这种硬件结构装置的实时性、可靠性和扩展性得到了极大的提高;控制保护单元和录波单元通过集线器与远程监控单元相连,同时控制保护单元和录波单元也有各自的监控界面,方便进行就地调试和监控。装置采用分层设计,中上层控制策略用C语言编程实现,易于进行各种控制策略和保护的研究。利用所研制的实验装置,分别在电容电压同步方式和线路电流同步方式下,进行了TCSC的基频阻抗特性实验。实验结果表明,该TCSC实验装置能够快速调节阻抗,并能灵活地完成不同阻抗模式之间的切换。
