2,113 research outputs found

    Trace organic analyses of effluent waters from a model slurry pipeline carrying Appalachian bituminous coal : final report

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    Effluent waters from a model coal slurry pipeline have been analyzed for trace dissolved organic compounds. The model pipeline was operated under conditions simulating those proposed for a slurry pipeline from the region of Bristol to Hampton Roads, Virginia. Acidic, neutral and basic organic compounds in the separated waters were determined. Concentrations of individual compounds detected were generally less than 0.5 ppb and never exceeded 6 ppb. Adsorption experiments using coal slurry sorbents indicate that coal particles act as sorbing surfaces under coal slurry pipeline transport conditions

    Marxism Lost and Found: Alasdair MacIntyre and the Contemporary Debate

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    This paper examines the changing nature of debates that focus on the philosophy of Alasdair MacIntyre. Whilst outlining the history of MacIntyre’s engagement with Marxism and some of his key ideas, it argues that it is only recently that such debates have begun to rightfully recognise the continued relevance of Marxism to such discussions. I note that crucial aspects of MacIntyre’s politics and philosophy, particularly his opposition to capitalism, are now integral to the contemporary debate which helps in generating a shared vision of radical politics. Nevertheless, I point out that key disagreements still remain as to the role of Marxism within such debates, the validity of MacIntyre’s critique of Marxism, as well as the potentially problematic post-Marxist practice that MacIntyre advocates in After Virtue and beyond

    Effects of Tropical Storm Agnes on Nutrient Flux and Distribution in Lower Chesapeake Bay

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    Nutrient concentrations measured in lower Chesapeake Bay in the summer of 1972 immediately following the flooding associated with Tropical Storm Agnes are compared with those in the summer of 1973, a season of more normal rainfall. The large amount of land runoff produced unseasonably high concentrations of dissolved inorganic nitrogen in the Bay near the mouth of the Potomac River. Phosphate concentrations were essentially unaffected by the flooding. Fluxes of total nitrogen and total phosphorus nutrients through the mouth of Chesapeake Bay were calculated for both summers. The calculated net export of nutrients from the Bay in both August 1972, and June 1973 was found to be small in comparison to nutrient inputs.https://scholarworks.wm.edu/vimsbooks/1068/thumbnail.jp

    Hydrocarbon fuel chemistry : sediment water interaction

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    The objective of this program was to determine the effect of sediments on aqueous solutions of selected United States Air Force (USAF} hydrocarbon fuels. Effects of sediment type, organic carbon content, pH, temperature and salinity on interaction of dissolved hydrocarbons with sediment were studied. The results of this work can be used to estimate the role of sediment hydrocarbon interaction terms in fate models of aqueous systems, such as the Environmental Protection Agency EXAMS model

    Boundary breathers in the sinh-Gordon model

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    We present an investigation of the boundary breather states of the sinh-Gordon model restricted to a half-line. The classical boundary breathers are presented for a two parameter family of integrable boundary conditions. Restricting to the case of boundary conditions which preserve the \phi --> -\phi symmetry of the bulk theory, the energy spectrum of the boundary states is computed in two ways: firstly, by using the bootstrap technique and subsequently, by using a WKB approximation. Requiring that the two descriptions of the spectrum agree with each other allows a determination of the relationship between the boundary parameter, the bulk coupling constant, and the parameter appearing in the reflection factor derived by Ghoshal to describe the scattering of the sinh-Gordon particle from the boundary.Comment: 16 pages amslate

    Do residents’ perceptions of being well-placed and objective presence of local amenities match? A case study in West Central Scotland, UK

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    Background:<p></p> Recently there has been growing interest in how neighbourhood features, such as the provision of local facilities and amenities, influence residents’ health and well-being. Prior research has measured amenity provision through subjective measures (surveying residents’ perceptions) or objective (GIS mapping of distance) methods. The latter may provide a more accurate measure of physical access, but residents may not use local amenities if they do not perceive them as ‘local’. We believe both subjective and objective measures should be explored, and use West Central Scotland data to investigate correspondence between residents’ subjective assessments of how well-placed they are for everyday amenities (food stores, primary and secondary schools, libraries, pharmacies, public recreation), and objective GIS-modelled measures, and examine correspondence by various sub-groups.<p></p> Methods:<p></p> ArcMap was used to map the postal locations of ‘Transport, Health and Well-being 2010 Study’ respondents (n = 1760), and the six amenities, and the presence/absence of each of them within various straight-line and network buffers around respondents’ homes was recorded. SPSS was used to investigate whether objective presence of an amenity within a specified buffer was perceived by a respondent as being well-placed for that amenity. Kappa statistics were used to test agreement between measures for all respondents, and by sex, age, social class, area deprivation, car ownership, dog ownership, walking in the local area, and years lived in current home.<p></p> Results:<p></p> In general, there was poor agreement (Kappa <0.20) between perceptions of being well-placed for each facility and objective presence, within 800 m and 1000 m straight-line and network buffers, with the exception of pharmacies (at 1000 m straight-line) (Kappa: 0.21). Results varied between respondent sub-groups, with some showing better agreement than others. Amongst sub-groups, at 800 m straight-line buffers, the highest correspondence between subjective and objective measures was for pharmacies and primary schools, and at 1000 m, for pharmacies, primary schools and libraries. For road network buffers under 1000 m, agreement was generally poor.<p></p> Conclusion:<p></p> Respondents did not necessarily regard themselves as well-placed for specific amenities when these amenities were present within specified boundaries around their homes, with some exceptions; the picture is not clear-cut with varying findings between different amenities, buffers, and sub-groups

    The Present State of Organic Xenobiotics in the Chesapeake Bay - A Synthesis Paper

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    This manuscript discusses the results of the first two and one half years of a three-year study designed to determine the present state of xenobiotic compounds in the Chesapeake Bay. It shows that polynuclear aromatic hydrocarbons are the most frequently encountered compounds and are the most abundant. Concentrations are highest in the Northern Bay with several sources implicated. During this study an apparent dumping of the pesticide, DDT, occurred. Either the quantity disposed of was small enough or the assimulation capacity was large enough that no adverse effects were noted. The detection by us of 6-phenyldodecane in bottom sediments of the Patapsco River and its detection in a nearby industrial outfall by the Monsanto Research Corporation shows that chemicals entering the River can be dispersed throughout the system and can enter the Chesapeake Bay

    Ten myths about character, virtue and virtue education – plus three well-founded misgivings

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    Initiatives to cultivate character and virtue in moral education at school continue to provoke sceptical responses. Most of those echo familiar misgivings about the notions of character, virtue and education in virtue – as unclear, redundant, old-fashioned, religious, paternalistic, anti-democratic, conservative, individualistic, relative and situation dependent. I expose those misgivings as ‘myths’, while at the same time acknowledging three better-founded historical, methodological and practical concerns about the notions in question

    Boundary Reflection Matrix for D4(1)D_4^{(1)} Affine Toda Field Theory

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    We present one loop boundary reflection matrix for d4(1)d_4^{(1)} Toda field theory defined on a half line with the Neumann boundary condition. This result demonstrates a nontrivial cancellation of non-meromorphic terms which are present when the model has a particle spectrum with more than one mass. Using this result, we determine uniquely the exact boundary reflection matrix which turns out to be \lq non-minimal' if we assume the strong-weak coupling \lq duality'.Comment: 14 pages, Late

    Terahertz oscillations in an In<sub>0.53</sub>Ga<sub>0.47</sub>As submicron planar gunn diode

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    The length of the transit region of a Gunn diode determines the natural frequency at which it operates in fundamental mode – the shorter the device, the higher the frequency of operation. The long-held view on Gunn diode design is that for a functioning device the minimum length of the transit region is about 1.5μm, limiting the devices to fundamental mode operation at frequencies of roughly 60 GHz. Study of these devices by more advanced Monte Carlo techniques that simulate the ballistic transport and electron-phonon interactions that govern device behaviour, offers a new lower bound of 0.5μm, which is already being approached by the experimental evidence that has shown planar and vertical devices exhibiting Gunn operation at 600nm and 700nm, respectively. The paper presents results of the first ever THz submicron planar Gunn diode fabricated in In&lt;sub&gt;0.53&lt;/sub&gt;Ga&lt;sub&gt;0.47&lt;/sub&gt;A on an InP substrate, operating at a fundamental frequency above 300 GHz. Experimentally measured rf power of 28 µW was obtained from a 600 nm long ×120 µm wide device. At this new length, operation in fundamental mode at much higher frequencies becomes possible – the Monte Carlo model used predicts power output at frequencies over 300 GHz
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