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Abstract One of the most talked about issues with respect to development, transportation, and conversion of the energy resources of the Western United States is the water requirement and its consequent impacts upon the ambience of that part of the country. In conjunction with other studies conducted by the US Geological Survey of water use in the conversion and transportation of the West's coal, an analysis of water use and environmental implications of coal slurry pipeline transport is presented. Simulations of a hypothetical slurry pipeline of 1000 mile length transporting 12.5 million tons per year indicate that pipeline costs and energy requirements are quite sensitive to the coal-to-water ratio. For realistic water prices, the optimal ratio will not vary far from the 50/50 ratio by weight. In comparison to other methods of energy conversion and transport, coal slurry pipelines utilize about a third of the amount of water required for coal gasification, and about a fifth of the amount required for onsite electrical generation. An analysis of net energy output from operating alternative energy transportation systems for the assumed conditions indicates that both slurry pipeline and rail shipment require approximately 4.5 per cent of the potential electrical energy output of the coal transported and high-voltage, direct-current transportation requires approximately 6.5 per cent. The environmental impacts of the different transport options are so substantially different that a common basis for comparison does not exist. 相似文献
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STEPHEN J. LIVINGSTONE COLM Ó COFAIGH DAVID J.A. EVANS ADRIAN PALMER 《Boreas: An International Journal of Quaternary Research》2010,39(3):505-527
Livingstone, S. J., Ó Cofaigh, C., Evans, D. J. A. & Palmer, A. 2010: Sedimentary evidence for a major glacial oscillation and proglacial lake formation in the Solway Lowlands (Cumbria, UK) during Late Devensian deglaciation. Boreas, Vol. 39, pp. 505–527. 10.1111/j.1502‐3885.2010.00149.x. ISSN 0300‐9483. This paper is a sedimentological investigation of Late Devensian glacial deposits from the Solway Lowlands, northwest England, in the central sector of the last British–Irish Ice Sheet. In this region, laminated glaciolacustrine sediments occur, sandwiched between diamictons interpreted as subglacial tills. At one location the laminated sediments are interpreted as varves, and indicate the former presence of a proglacial lake. Correlation of these varves with other laminated sediments indicates that the glacial lake was at least 140 km2 in area and probably much larger. Extensive beds of sand, silt and gravel throughout the Solway Basin associated with the lake demonstrate ice‐free conditions over a large area. Based on the number of varves, the lake was in existence for at least 261 years. The stratigraphic sequence of varves bracketed by tills implies a major glacial oscillation prior to the Scottish Re‐advance (16.8 cal. ka BP). This oscillation is tentatively correlated with the Gosforth oscillation at c.19.5 cal. ka BP. Subsequent overriding of these glaciolacustrine sediments during a westward‐moving re‐advance demonstrates rapid ice loss and then gain within the Solway Lowlands from ice‐dispersal centres in the Lake District, Pennines and Southern Uplands. It is speculated that the existence of this and other lakes along the northeastern edge of the Irish Sea Basin would have influenced ice‐sheet dynamics. 相似文献
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Abstract– The study of aqueous alteration of kamacite in CM chondrites provides insight on the conditions, products, and relative timing of aqueous alteration. We studied unaltered, partially altered, and fully altered kamacite grains from Murray, Murchison, Cold Bokkeveld, and Nogoya using optical microscopy, electron microprobe analysis, scanning electron microscopy, and Raman spectroscopy. From textual evidence and chemical analysis, we established three separate microchemical environments. 1) In a microchemical environment with a high S activity, kamacite alters to form tochilinite, P‐bearing sulfides, eskolaite, and schreibersite. Mass balance calculations show that 81% of the Fe in kamacite is removed from the alteration region, making it available for the formation of other minerals or Fe‐rich aureoles. The release of Fe can alter the mesostasis of type‐I chondrules forming cronstedtite. 2) In a microchemical environment with a high Si activity and a low S activity, kamacite alters to form cronstedtite with small accessory sulfide inclusions. 3) A microchemical environment with limited S and Si activity results in kamacite alteration forming magnetite. The resulting magnetite retains associated Ni that can distinguish it from precipitated magnetite. In addition, the accessory phases of pentlandite and apatite can be formed if S or Ca are present. Finally, we note that small tochilinite grains in the matrix lack typical Ni, P, and Co levels, suggesting that they did not form from kamacite but possibly by sulfidization of magnetite. 相似文献
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Ken-ichi SHIMOSE Ming XUE Robert D. PALMER Jidong GAO Boon Leng CHEONG David J. BODINE 《大气科学进展》2013,30(2):291-305
Because they are most sensitive to atmospheric moisture content, radar refractivity observations can provide high-resolution information about the highly variable low-level moisture field. In this study, simulated radar refractivity-related phase-change data were created using a radar simulator from realistic highresolution model simulation data for a dryline case. These data were analyzed using the 2DVAR system developed specifically for the phase-change data. Two sets of experiments with the simulated observations were performed, one assuming a uniform target spacing of 250 m and one assuming nonuniform spacing between 250 m to 4 km. Several sources of observation error were considered, and their impacts were examined. They included errors due to ground target position uncertainty, typical random errors associated with radar measurements, and gross error due to phase wrapping. Without any additional information, the 2DVAR system was incapable of dealing with phase-wrapped data directly. When there was no phase wrapping in the data, the 2DVAR produced excellent analyses, even in the presence of both position uncertainty and random radar measurement errors. When a separate pre-processing step was applied to unwrap the phase-wrapped data, quality moisture analyses were again obtained, although the analyses were smoother due to the reduced effective resolution of the observations by interpolation and smoothing involved in the unwrapping procedure. The unwrapping procedure was effective even when significant differences existed between the analyzed state and the state at a reference time. The results affirm the promise of using radar refractivity phase-change measurements for near-surface moisture analysis. 相似文献
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Guifu ZHANG Vivek N.MAHALE Bryan J.PUTNAM Youcun QI Qing CAO ANDrew D.BYRD Petar BUKOVCIC Dusan S.ZRNIC Jidong GAO Ming XUE Youngsun JUNG Heather D.REEVES Pamela L.HEINSELMAN AlexANDer RYZHKOV Robert D.PALMER Pengfei ZHANG Mark WEBER Greg M.MCFARQUHAR Berrien MOORE III Yan ZHANG Jian ZHANG J.VIVEKANANDAN Yasser AL-RASHID Richard L.ICE Daniel S.BERKOWITZ Chong-chi TONG Caleb FULTON Richard J.DOVIAK 《大气科学进展》2019,36(6):571-588
After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation. 相似文献
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JIRI CHLACHULA ROB A. KEMP CATHERINE A. JESSEN ADRIAN P. PALMER PHILLIP S. TOMS 《Boreas: An International Journal of Quaternary Research》2004,33(2):164-180
Two high-resolution loess-palaeosol sections from the Ob Loess Plateau (Iskitim) and the Minusinsk Basin (Kurtak 33) provide new detailed information on the last interglacial climate variations and landscape development in the parkland-steppe zone of southern Siberia. The complete last interglacial sensu lato (130-74 ka BP) records of the two sites, documented by magnetic susceptibility, grain-size, CaCO 3 and organic carbon content as proxy climatic data, and supplemented by thin-section studies, indicate several short warm and very cold intervals correlated with OIS 5e-5a. A strongly continental warm climate culminated around the peak of the last interglacial sensu stricto (OIS 5e) and cooler conditions occurred during the following interstadial stages (OIS 5c and 5a), corresponding to shifts in palaeolandscape development with gradual replacement of parkland-steppe and mixed southern taiga by boreal forest. During stadial stages (OIS 5d and 5b), the palaeolandscape was transformed into a cold arid periglacial tundra-steppe. Evidence for a major cooling in Siberia during OIS 5d, corroborating the palaeolimnological record from Lake Baikal, is provided by deep frost-wedge casts distorting the OIS 5e chernozemic palaeosol, suggesting formation of permafrost shortly after the last interglacial climatic optimum. The pedosedimentary record, reflecting the effects of syndepositional pedogenic processes, attests to a dynamic climate pulsation during the last interglacial stage. 相似文献
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Ancient marine organisms that excavated holes in shells and other calcium carbonate substrates on the sea bed have not been widely studied by palaeontologists. Together with scrape and scratch marks made by rasping grazers on shell surfaces, they constitute a group of hard–substrate trace fossils that have many modern equivalents. Even the smallest forms can be studied by casting the holes in plastic resin and dissolving the shell. The variety of borers increased in the Mesozoic Era, thereby avoiding the attentions of predatory groups that were radiating at the same time. 相似文献