20 research outputs found
Comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee
The thermal, ecological, and social impacts of a 40-reactor NEC are compared to impacts from four 10-reactor NECs and ten 4-reactor power plants. The comparison was made for surrogate sites in western Tennessee. The surrogate site for the 40-reactor NEC is located on Kentucky Lake. A layout is postulated for ten clusters of four reactors each with 2.5-mile spacing between clusters. The plants use natural-draft cooling towers. A transmission system is proposed for delivering the power (48,000 MW) to five load centers. Comparable transmission systems are proposed for the 10-reactor NECs and the 4-reactor dispersed sites delivering power to the same load centers. (auth
Geologic framework of the 2005 Keathley Canyon gas hydrate research well, northern Gulf of Mexico
This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 25 (2008): 906-918, doi:10.1016/j.marpetgeo.2008.01.012.The Keathley Canyon sites drilled in 2005 by the Chevron Joint Industry Project are located along the southeastern edge of an intraslope minibasin (Casey basin) in the northern Gulf of Mexico at 1335 m water depth. Around the drill sites, a grid of 2D high-resolution multichannel seismic data designed to image depths down to at least 1000 m sub-bottom reveals 7 unconformities and disconformities that, with the seafloor, bound 7 identifiable seismic stratigraphic units. A major disconformity in the middle of the units stands out for its angular baselapping geometry. From these data, three episodes of sedimentary deposition and deformation are inferred. The oldest episode consists of fine-grained muds deposited during a period of relative stability in the basin (units e, f, and g). Both the BSR and inferred gas hydrate occur within these older units. The gas hydrate occurs in near-vertical fractures. A second episode (units c and d) involved large vertical displacements associated with infilling and ponding of sediment. This second interval corresponds to deposition of intercalated fine and coarse-grained material that was recovered in the drill hole that penetrated the thin edges of the regionally much thicker units. The final episode of deposition (units a and b) occurred during more subdued vertical motions. Hemipelagic drape (unit a) characterizes the modern seafloor. The present-day Casey basin is mostly filled. Its sill is part of a subsiding graben structure that is only 10–20 m shallower than the deepest point in the basin, indicating that gravity-driven transport would mostly bypass the basin. Contemporary faulting along the basin margins has selectively reactivated an older group of faults. The intercalated sand and mud deposits of units c and d are tentatively correlated with Late Pleistocene deposition derived from the western shelf-edge delta/depocenter of the Mississippi River, which was probably most active from 320 ka to 70 ka [Winker, C.D., Booth, J., 2000. Sedimentary dynamics of the salt-dominated continental slope, Gulf of Mexico: integration of observations from the seafloor, near-surface, and deep subsurface. In: Proceedings of the GCSSEPM Foundation 20th Annual Research Conference, Deep-water Reservoirs of the World, pp. 1059–1086]. The presence of sand within the gas hydrate stability zone (in units c and d) is not sufficient to concentrate gas hydrate even though dispersed gas hydrate occurs deeper in the fractured mud/clay-rich sections of units e and f.Partial support for the field and interpretive aspects of this
project were provided by the Department of Energy, National Energy
Technology Lab (NETL)
Biotope gradient in a diversified New Guinea subsistence system
The Wopkaimin are a population of hunter-horticulturalists who live near the Upper Fly River in Papua New Guinea. In this paper, ecosystem heterogeneity is related to diversity of strategies in the Wopkaimin subsistence system. Subsistence subsystems of shifting cultivation, silviculture, gathering, pig raising, hunting, fishing, and collecting are associated with 11 biotopes. Biotopes are useful descriptive categories for subsistence ecological research and they are recognized Wopkaimin emic categories, having cognitive and behavioral consequences. The relationship of the Wopkaimin population to other biota in the ecosystem is shown to be related to a very steep biotope gradient
Ethnobotany of Wopkaimin Pandanus significant Papua New Guinea plant resource
Pandanus is well represented in Papua New Guinea with over 66 species growing from sea level to 3,000 m. The territory of the Wopkaimin, who live at the headwaters of the Ok Tedi in the Star and Hindenburg Mountains, is particularly rich in wild and domesticated species of Pandanus. Detailed analysis of the species in classification, ecology, subsistence, ritual and material culture not only establishes Pandanus as a locally significant plant resource but also contributes to the comparative understanding of ethnobiological systems. A close correspondence with botanical taxa of generic and specific rank and an absence of the most inclusive taxon term for plant are 2 cross-culturally important findings substantiated in Wopkaimin Pandanus taxonomy
Variability in body physique, ecology, and subsistence in the Fly River region of Papua New Guinea
There are some 40,000 indigenous peoples of the Fly River drainage in Papua New Guinea. The 4,000-mm rainfall contour ecologically demarcates hunter-horticulturalist peoples living in the rainforests of the Upper Fly from hunter-gatherer peoples living in the savanna-swamplands of the Middle and Lower Fly. A complex of factors operate to create significant physical differences between Upper Fly peoples and those of the Middle and Lower Fly. The ecological division between rainforests and savanna-swamplands demarcates a clear clinal separation by stature of Upper Fly peoples from those of the Middle and Lower Fly
Mining, modernisation and dietary change among the wopkaimin of papua new guinea
This paper examines retrospectively the changes in food and nutrient intake which have taken place over a nine-year period in which the intrusion of a major gold and copper mine has brought rapid socio-economic and ecological change to the Papua New Guinea Wopkaimin population, especially those who now rely upon cash incomes. A small proportion of the population remains subsistence-oriented. Since 1975 taro (Colocasia), the traditional staple, has become less important, and sweet potato (Ipomoea batatas) more so. Store-bought and imported western foods are the main sources of energy and protein for the population with cash income. Increased availability of food due to the relatively faster yielding sweet potato staple now cultivated at low elevations, and to the availability of money to buy food with, has resulted in increased energy intakes, but not of protein. Increased body mass of workers and workers' wives is attributed to this increase in energy intake
Metal(loid) pollution, not urbanisation nor parasites predicts low body condition in a wetland bioindicator snake
Urban ecosystems and remnant habitat 'islands' therein, provide important strongholds for many wildlife species including those of conservation significance. However, the persistence of these habitats can be undermined if their structure and function are too severely disrupted. Urban wetlands, specifically, are usually degraded by a monoculture of invasive vegetation, disrupted hydrology, and chronic-contamination from a suite of anthropogenic pollutants. Top predators—as bioindicators—can be used to assess and monitor the health of these ecosystems. We measured eight health parameters (e.g., parasites, wounds and scars, tail loss and body condition) in a wetland top predator, the western tiger snake, Notechis scutatus occidentalis. For three years, snakes were sampled across four wetlands along an urban gradient. For each site, we used GIS software to measure the area of different landscapes and calculate an urbanisation–landscape score. Previously published research on snake contamination informed our calculations of a metal-pollution index for each site. We used generalised linear mixed models to assess the relationship between all health parameters and site variables. We found the metal-pollution index to have the most significant association with poor body condition. Although parasitism, tail loss and wounds differed among sites, none of these parameters influenced body condition. Additionally, the suite of health parameters suggested differing health status among sites; however, our measure of contemporary landscape urbanisation was never a significant predictor variable. Our results suggest that the health of wetland predators surrounding a rapidly growing city may be offset by higher levels of environmental pollution