Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica...Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica, salamae, arizonae,展开更多
The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality proce...The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 ~tm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5x 107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.展开更多
Prostephanus truncatus (Horn) is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, deman...Prostephanus truncatus (Horn) is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, demands adequate preparation including identification of the potential invasion areas for more focused planning towards its effective management. In the current study, the potential P. truncatus invasion areas in Zimbabwe were identified based on climatic data with reference to the Tanzania situation using the geographical information system (GIS) Almanac Characterization Tool (AWhere-ACT 3.5 software). Areas identified to be at greatest risk of invasion includes the northern part of the country, the southern-east region and a few areas in the east (Manicaland province). Alternative host plants for P. truncatus similar to those identified in Kenya, where the pest is already endemic, were found to occur throughout Zimbabwe which could support initial colonization and subsequent perpetuation of the pest in the country. In Zimbabwe, chances that P. truncatus may spread throughout the country, should it invade the country, are high because of unregulated grain trade and the fact that most of the potential invasion areas identified in this study, are located in the major maize producing areas. Measures to delay the occurrence of the pest in Zimbabwe should focus on the high-risk areas identified.展开更多
基金financially supported by the University of Malaya Research Grant (UMRG) (RP003A-13BIO)UM Postgraduate Research Fund (PPP) (PS319/2010B)
文摘Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica, salamae, arizonae,
基金supported by National Natural Science Foundation for Young Scholars of China(Grant No.51205053)National Natural Science Foundation of China(Grant No.51075064)
文摘The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 ~tm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5x 107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.
文摘Prostephanus truncatus (Horn) is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, demands adequate preparation including identification of the potential invasion areas for more focused planning towards its effective management. In the current study, the potential P. truncatus invasion areas in Zimbabwe were identified based on climatic data with reference to the Tanzania situation using the geographical information system (GIS) Almanac Characterization Tool (AWhere-ACT 3.5 software). Areas identified to be at greatest risk of invasion includes the northern part of the country, the southern-east region and a few areas in the east (Manicaland province). Alternative host plants for P. truncatus similar to those identified in Kenya, where the pest is already endemic, were found to occur throughout Zimbabwe which could support initial colonization and subsequent perpetuation of the pest in the country. In Zimbabwe, chances that P. truncatus may spread throughout the country, should it invade the country, are high because of unregulated grain trade and the fact that most of the potential invasion areas identified in this study, are located in the major maize producing areas. Measures to delay the occurrence of the pest in Zimbabwe should focus on the high-risk areas identified.