228 research outputs found

    Quasi Harmonic Lattice Dynamics and Molecular Dynamics calculations for the Lennard-Jones solids

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    We present Molecular Dynamics (MD), Quasi Harmonic Lattice Dynamics (QHLD) and Energy Minimization (EM) calculations for the crystal structure of Ne, Ar, Kr and Xe as a function of pressure and temperature. New Lennard-Jones (LJ) parameters are obtained for Ne, Kr and Xe to reproduce the experimental pressure dependence of the density. We employ a simple method which combines results of QHLD and MD calculations to achieve densities in good agreement with experiment from 0 K to melting. Melting is discussed in connection with intrinsic instability of the solid as given by the QHLD approximation. (See http://www.fci.unibo.it/~valle for related papers)Comment: 7 pages, 5 figures, REVte

    Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

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    Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires

    Measurement in Economics and Social Science

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    The paper discusses measurement, primarily in economics, from both analytical and historical perspectives. The historical section traces the commitment to ordinalism on the part of economic theorists from the doctrinal disputes between classical economics and marginalism, through the struggle of orthodox economics against socialism down to the cold-war alliance between mathematical social science and anti-communist ideology. In economics the commitment to ordinalism led to the separation of theory from the quantitative measures that are computed in practice: price and quantity indexes, consumer surplus and real national product. The commitment to ordinality entered political science, via Arrow’s ‘impossibility theorem’, effectively merging it with economics, and ensuring its sterility. How can a field that has as its central result the impossibility of democracy contribute to the design of democratic institutions? The analytical part of the paper deals with the quantitative measures mentioned above. I begin with the conceptual clarification that what these measures try to achieve is a restoration of the money metric that is lost when prices are variable. I conclude that there is only one measure that can be embedded in a satisfactory economic theory, free from unreasonable restrictions. It is the Törnqvist index as an approximation to its theoretical counterpart the Divisia index. The statistical agencies have at various times produced different measures for real national product and its components, as well as related concepts. I argue that all of these are flawed and that a single deflator should be used for the aggregate and the components. Ideally this should be a chained Törnqvist price index defined on aggregate consumption. The social sciences are split. The economic approach is abstract, focused on the assumption of rational and informed behavior, and tends to the political right. The sociological approach is empirical, stresses the non-rational aspects of human behavior and tends to the political left. I argue that the split is due to the fact that the empirical and theoretical traditions were never joined in the social sciences as they were in the natural sciences. I also argue that measurement can potentially help in healing this split

    How COVID-19 impacted child and family health and healthcare: a mixed-methods study incorporating family voices

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    To describe how social disruptions caused by the COVID-19 pandemic impacted child access to healthcare and child health behaviors in 2020. We used mixed-methods to conduct surveys and in-depth interviews with English- and Spanish-speaking parents of young children from five geographic regions in the USA. Participants completed the COVID-19 Exposure and Family Impact Survey (CEFIS). Semistructured telephone interviews were conducted between August and October 2020. Of the 72 parents interviewed, 45.8% of participants were Hispanic, 20.8% Black (non-Hispanic), and 19.4% White (non-Hispanic). On the CEFIS, the average (SD) number of social/family disruptions reported was 10.5 (3.8) out of 25. Qualitative analysis revealed multiple levels of themes that influenced accessing healthcare during the pandemic, including two broad contextual themes: (a) lack of trustworthiness of medical system/governmental organizations, and (b) uncertainty due to lack of consistency across multiple sources of information. This context influenced two themes that shaped the social and emotional environments in which participants accessed healthcare: (a) fear and anxiety and (b) social isolation. However, the pandemic also had some positive impacts on families: over 80% indicated that the pandemic made it "a lot"or "a little"better to care for their new infants. Social and family disruptions due to COVID-19 were common. These disruptions contributed to social isolation and fear, and adversely impacted multiple aspects of child and family health and access to healthcare. Some parents of infants reported improvements in specific health domains such as parenting, possibly due to spending more time together

    Science and Ideology in Economic, Political, and Social Thought

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    This paper has two sources: One is my own research in three broad areas: business cycles, economic measurement and social choice. In all of these fields I attempted to apply the basic precepts of the scientific method as it is understood in the natural sciences. I found that my effort at using natural science methods in economics was met with little understanding and often considerable hostility. I found economics to be driven less by common sense and empirical evidence, then by various ideologies that exhibited either a political or a methodological bias, or both. This brings me to the second source: Several books have appeared recently that describe in historical terms the ideological forces that have shaped either the direct areas in which I worked, or a broader background. These books taught me that the ideological forces in the social sciences are even stronger than I imagined on the basis of my own experiences. The scientific method is the antipode to ideology. I feel that the scientific work that I have done on specific, long standing and fundamental problems in economics and political science have given me additional insights into the destructive role of ideology beyond the history of thought orientation of the works I will be discussing

    The Social-Psychological Bases of Far-Right Support in Europe and the United States

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    The roles of authoritarianism, social dominance orientation (SDO), and prejudice in the prediction of far-right support were examined in Europe and the United States (U.S.). A meta-analysis shows remarkably similar, positive and strong associations of far-right support with these three variables in previous studies conducted in Europe, the United Kingdom (U.K.), and the United States. Results from two cross-sectional studies in the U.S. further indicated that higher levels of authoritarianism and SDO related to higher voting intentions and support for Trump, via increased prejudice. In a three-wave longitudinal study in the U.K., authoritarianism and SDO predicted pro-Brexit attitudes and support for the United Kingdom Independence Party, again via prejudice. These results shed a new light on the widely-held beliefs in “American and British exceptionalism”, as Trump and Brexit adherents share the same social-psychological underpinnings as far-right supporters observed in several European countries

    Anti-Equivalence: Pragmatics of post-liberal dispute

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    In the early 21st century, liberal democracies have witnessed their foundational norms of critique and deliberation being disrupted by a combination of populist and technological forces. A distinctive style of dispute has appeared, in which a speaker denounces the unfairness of all liberal and institutional systems of equivalence, including the measures of law, economics and the various other ‘tests’ which convention scholars have deemed core to organisations. The article reviews how sociologists of critique have tended to treat critical capacities as oriented towards consensus, but then considers how technologies of real-time ‘control’ circumvent liberal critique altogether. In response, a different type of dispute emerges in the digital public sphere, which abandons equivalences in general, instead adopting a non-representational template of warfare. This style of post-liberal dispute is manifest in the rhetoric of populists, but does not originate there
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