2,822 research outputs found

    (SNP098) Sattie Mundy interviewed by Amanda Moody, transcribed by Peggy C. Bradley, updated by Mark S. Purington

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    Records an interview with Sattie Mundy, (née Good), who spent several summers as a young girl at the Black Rock Springs Hotel, in Black Rock Gap, Virginia. The Black Rock Springs Hotel was a popular tourist destination in the late 19th and early 20th centuries, both for its scenic views and for the natural mineral springs for which it was named. Mrs. Mundy recounts her memories of the grounds and buildings and the popularity of the site in the years following the hotel\u27s destruction by fire in 1909. Includes references to people associated with the hotel and springs, as well as many of the families and local people who lived near the hotel in its heyday. The site where the hotel stood was incorporated into Shenandoah National Park in the 1930s. Also contributing to the interview were Mrs. Mundy\u27s daughter and son-in-law, Marie and Jay Bowman.https://commons.lib.jmu.edu/snp/1080/thumbnail.jp

    Real single ion solvation free energies with quantum mechanical simulation

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    Single ion solvation free energies are one of the most important properties of electrolyte solutions and yet there is ongoing debate about what these values are. Only the values for neutral ion pairs are known. Here, we use DFT interaction potentials with molecular dynamics simulation (DFT-MD) combined with a modified version of the quasi-chemical theory (QCT) to calculate these energies for the lithium and fluoride ions. A method to correct for the error in the DFT functional is developed and very good agreement with the experimental value for the lithium fluoride pair is obtained. Moreover, this method partitions the energies into physically intuitive terms such as surface potential, cavity and charging energies which are amenable to descriptions with reduced models. Our research suggests that lithium's solvation free energy is dominated by the free energetics of a charged hard sphere, whereas fluoride exhibits significant quantum mechanical behavior that cannot be simply described with a reduced model.Comment: 13 pages, 4 figure

    Electrostatic solvation free energies of charged hard spheres using molecular dynamics with density functional theory interactions

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    Determining the solvation free energies of single ions in water is one of the most fundamental problems in physical chemistry and yet many unresolved questions remain. In particular, the ability to decompose the solvation free energy into simple and intuitive contributions will have important implications for models of electrolyte solution. Here, we provide definitions of the various types of single ion solvation free energies based on different simulation protocols. We calculate solvation free energies of charged hard spheres using density functional theory interaction potentials with molecular dynamics simulation (DFT-MD) and isolate the effects of charge and cavitation, comparing to the Born (linear response) model. We show that using uncorrected Ewald summation leads to unphysical values for the single ion solvation free energy and that charging free energies for cations are approximately linear as a function of charge but that there is a small non-linearity for small anions. The charge hydration asymmetry (CHA) for hard spheres, determined with quantum mechanics, is much larger than for the analogous real ions. This suggests that real ions, particularly anions, are significantly more complex than simple charged hard spheres, a commonly employed representation.Comment: 28 pages, 5 figure

    Economic lot sizes in a multi-stage production-inventory system

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    A simulation model was programmed to investigate the behaviour of the system cost function for a simple 2-stage system with four raw material inventories; static, deterministic demand, and various production rates

    EDUCATIONAL PROGRAMS TO ADDRESS THE ECONOMIC ADJUSTMENTS FACING TOBACCO FARMERS AND RURAL COMMUNITIES

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    This paper discusses the context within which educational programs tailored to tobacco producers and related rural communities have developed. Discussion is expanded by examining current program approaches employed by various organizations. Many of these organizations have a manual stake in helping producers in tobacco communities develop their management capacity. A range of initiatives aimed at facilitating economic adjustment is compared, including the major issues addressed and expected outcomes. Many of the initiatives have made useful contributions; however, gaps and limitations remain. These are considered as future educational efforts and issues are discussed.educational programs, tobacco producers, Community/Rural/Urban Development,

    Molecular abundances and low-mass star formation. I: Si- and S-bearing species toward IRAS 16293-2422

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    Results from millimeter and submillimeter spectral line surveys of the protobinary source IRAS 16293-2422 are presented. Here we outline the abundances of silicon- and sulfur-containing species. A combination of rotation diagram and full statistical equilibrium/radiative transfer calculations is used to constrain the physical conditions toward IRAS 16293 and to construct its beam-averaged chemical composition over a 10-20" (1600-3200 AU) scale. The chemical complexity as judged by species such as SiO, OCS, and H_2S, is mtermedtate between that of dark molecular clouds such as Ll34N and hot molecular cloud cores such as Orion KL. From the richness of the spectra compared to other young stellar objects of similar luminosity, it is clear that molecular abundances do not scale simply with mass; rather, the chemistry is a strong function of evolutionary state, i.e., age
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