This study aimed at the geographical variation in methods of processing shea butter that has been passed on from generation to generation and storage procedures （materials and containers used/perceived shelf life of ...This study aimed at the geographical variation in methods of processing shea butter that has been passed on from generation to generation and storage procedures （materials and containers used/perceived shelf life of the products used for preservation and local perceptions about rancidity）. Little variation was found in indigenous processing methods, utilization and storage across most of the three regions. Only among the Dagomba tribe in the Northern region did women intentionally use shrubs to add yellow colour to butter particularly that for the market. The use of onions and lemon/lime leaves to prevent rancidity and also improve the taste and smell of butter was found to be practiced by only one missionary group. Perception about shelf life of the butter was found to vary widely among the processors and consumers （3 months to 2 years）. Though this was the main focus of the study, most of the indigenous processors and consumers apart from the missionary group had little experience as far as this problem was concerned. This was due to the fact that most of them consumed the butter within one or two months after processing and so the product is not kept long enough to give any appreciable signs of rancidity.展开更多
Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful...Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful in overcoming non-linear dynamic behavior, uncertain and time-varying parameters, un-modeled dynamics, and couples between the automatic turbulence control (ATC) and the automatic acid temperature control (AATC) with varying parameters during the operation process. The quasi-cascade control system of inner and outer loop self-adaptive fuzzy PID controller was built, which could effectively control the pickling speed of plates and strips. The simulated results and real application indicate that the plates and strips acid pickling speed control system has good performances of adaptively tracking the parameter variations and anti-disturbances, which ensures the match of acid pickling temperature and turbulence of flowing with acid pickling speed, improving the surface quality of plates and strips acid pickling, and energy efficiency.展开更多
文摘This study aimed at the geographical variation in methods of processing shea butter that has been passed on from generation to generation and storage procedures （materials and containers used/perceived shelf life of the products used for preservation and local perceptions about rancidity）. Little variation was found in indigenous processing methods, utilization and storage across most of the three regions. Only among the Dagomba tribe in the Northern region did women intentionally use shrubs to add yellow colour to butter particularly that for the market. The use of onions and lemon/lime leaves to prevent rancidity and also improve the taste and smell of butter was found to be practiced by only one missionary group. Perception about shelf life of the butter was found to vary widely among the processors and consumers （3 months to 2 years）. Though this was the main focus of the study, most of the indigenous processors and consumers apart from the missionary group had little experience as far as this problem was concerned. This was due to the fact that most of them consumed the butter within one or two months after processing and so the product is not kept long enough to give any appreciable signs of rancidity.
基金Project(51090385) supported by the National Natural Science Foundation of ChinaProject(2001IB001) supported by Yunnan Provincial Science and Technology Fund, China
文摘Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful in overcoming non-linear dynamic behavior, uncertain and time-varying parameters, un-modeled dynamics, and couples between the automatic turbulence control (ATC) and the automatic acid temperature control (AATC) with varying parameters during the operation process. The quasi-cascade control system of inner and outer loop self-adaptive fuzzy PID controller was built, which could effectively control the pickling speed of plates and strips. The simulated results and real application indicate that the plates and strips acid pickling speed control system has good performances of adaptively tracking the parameter variations and anti-disturbances, which ensures the match of acid pickling temperature and turbulence of flowing with acid pickling speed, improving the surface quality of plates and strips acid pickling, and energy efficiency.
