Coal preparation is an integral part of the coal commodity supply chain. This stage of post-mining, pre-utilization beneficiation uses low-cost separation technologies to remove unwanted mineral matter and moisture wh...Coal preparation is an integral part of the coal commodity supply chain. This stage of post-mining, pre-utilization beneficiation uses low-cost separation technologies to remove unwanted mineral matter and moisture which hinder the value of the coal product. Coal preparation plants typically employ several parallel circuits of cleaning and dewatering operations, with each circuit designed to optimally treat a specific size range of coal. Recent innovations in coal preparation have increased the efficiency and capac- ity of individual unit operations while reinforcing the standard parallel cleaning approach. This article, which describes the historical influences and state-of-the-art design for the various coal preparation unit operations, is organized to distinguish between coarse/intermediate coal cleaning and fine/ultrafine coal cleaning. Size reduction, screening, classification, cleaning, dewatering, waste disposal unit operations are particularly highlighted, with a special focus on the LI.S. design philosophy. Notable differences between the U.S. and international operations are described as appropriate.展开更多
This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. Th...This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. The work-unit system was an employment system under which the vast majority of the population, in both urban and rural areas, had guaranteed employment and a host of benefits, including health insurance and access to the public health and health care systems. This system was created in the 1950s, which coincided with the decline of TB mortality and morbidity. The 1990s dismantling of the work-unit system has coincided with resurgent TB. This comparative historical sociological work examines TB control in Shanghai at three critical junctures： before the work-unit system was constructed, while it was in place, and since it has been dismantled. I examine both Shanghai＇s urban districts and rural counties, based on data gathered from archival sources and in-depth interviews during 17 months of field research. I argue that the work-unit system provided an effective basic-level infrastructure for the provision of public health and health care services that reached the entire population. This infrastructure was critical to the success of TB control efforts during the work-unit era, and its dismantling has been a key cause of the faltering of TB control in recent years.展开更多
文摘Coal preparation is an integral part of the coal commodity supply chain. This stage of post-mining, pre-utilization beneficiation uses low-cost separation technologies to remove unwanted mineral matter and moisture which hinder the value of the coal product. Coal preparation plants typically employ several parallel circuits of cleaning and dewatering operations, with each circuit designed to optimally treat a specific size range of coal. Recent innovations in coal preparation have increased the efficiency and capac- ity of individual unit operations while reinforcing the standard parallel cleaning approach. This article, which describes the historical influences and state-of-the-art design for the various coal preparation unit operations, is organized to distinguish between coarse/intermediate coal cleaning and fine/ultrafine coal cleaning. Size reduction, screening, classification, cleaning, dewatering, waste disposal unit operations are particularly highlighted, with a special focus on the LI.S. design philosophy. Notable differences between the U.S. and international operations are described as appropriate.
文摘This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. The work-unit system was an employment system under which the vast majority of the population, in both urban and rural areas, had guaranteed employment and a host of benefits, including health insurance and access to the public health and health care systems. This system was created in the 1950s, which coincided with the decline of TB mortality and morbidity. The 1990s dismantling of the work-unit system has coincided with resurgent TB. This comparative historical sociological work examines TB control in Shanghai at three critical junctures： before the work-unit system was constructed, while it was in place, and since it has been dismantled. I examine both Shanghai＇s urban districts and rural counties, based on data gathered from archival sources and in-depth interviews during 17 months of field research. I argue that the work-unit system provided an effective basic-level infrastructure for the provision of public health and health care services that reached the entire population. This infrastructure was critical to the success of TB control efforts during the work-unit era, and its dismantling has been a key cause of the faltering of TB control in recent years.
