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Full-Text Articles in Physical Sciences and Mathematics
Production And Economic Analyses Of Woody Biomass Utilization For Energy, John Edward Vance
Production And Economic Analyses Of Woody Biomass Utilization For Energy, John Edward Vance
Graduate Theses, Dissertations, and Problem Reports
A mechanized harvest system combined with whole-tree chipper producing mixed hardwood chips was investigated on two harvesting sites in the central Appalachian region, USA. Production and machine rate data of the operations were collected through time-motion study, with chipping time elements categorized into feeding, chipping, and loading. Chipping cycles averaged 21.5 minutes to produce 23.54 green tons per truckload, providing an hourly rate of 65.82 green tons/PMH (41.1 dry tons) by the whole-tree chipper. Total cycle time including truck delivery averaged 183 minutes, giving an hourly rate of 7.7 green tons/PMH (4.8 dry tons/PMH). The hourly cost of the harvesting …
Wintering American Black Duck Ecology Of Central Appalachia, Sara E. Yannuzzi
Wintering American Black Duck Ecology Of Central Appalachia, Sara E. Yannuzzi
Graduate Theses, Dissertations, and Problem Reports
The American black duck (Anas rubripes) is a species of dabbling duck found only in the northeastern part of North America, and widely hunted until its decline. Since the 1950s, the total population has decreased by 53%. Habitat degradation and decline of wintering and breeding wetlands, historic overharvest, and interactions with the mallard (A. platyrhynchos) are attributed as some of the main causes of the black duck population’s decrease. Many policies and taxa- and habitat-specific joint ventures have since been created to aid in studying and improving North American wetlands and black duck populations throughout both their breeding and wintering …