142 research outputs found

    Deterioration of stone and mineral materials from the Roman Imperial “Cilla of the Antonines” at ancient lanuvium

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    The “Villa of the Antonines”, located at the 18th mile of the ancient Via Appia, is so far the least explored of the ancient Roman imperial residences in the area of the Alban Hills. Excavations at “Villa of the Antonines” permit an investigation of subsurface deterioration of cultural stone, addressing two primary questions: (1) What are the deterioration processes in the soil and sediment environment, and how do these compare to subaerial deterioration processes? (2) How might the deterioration impact other methodologies reliant on the analysis of the material, such as use and wear analysis, dating techniques, and provenience by chemical tracers? The deterioration characteristics of materials recovered thus far can be visually described. Marbles are discolored and exhibit a loss of polish and partial to extensive granular disintegration and powdering. Brick varies in color and composition due to manufacturing and material differences, but may also exhibit within-soil alteration. Glass tesserae exhibit frosting and pitting from chemical solution. Scanning electron microscopy (SEM) reveals surface microdeterioration such as pitting, etching, and glazing. Qualitative backscatter electron microscopy (BSEM) and energy dispersive spectroscopy (EDS) indicate the distribution of elements, including byproducts of chemical deterioration, likely within the soil environment

    Prospectus, December 13, 1978

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    SEASON\u27S GREETINGS; Merry Christmas from the Prospectus Staff; Two PC paintings taken from campus Monday; State is accepting grant applications; Duet coming to PC Dec. 17; PC dinner dance is cancelled; Applications being accepted; Final exams are Dec. 15-21; PC Speech Team captures fifth; Joseph Cronin speaks at Parkland on education; St. Nick\u27s origins revealed in story; The Spirit of Christmas; That Christmas Feeling; Extra second to be added to clocks at the end of the last day of this year; Toys for tots a success; Holiday customs differ; Christmas tree owners...Avoid fire hazards with hints; Hannukah and X-mas to be celebrated on same day this year; Mother hopes to avoid Christmas gift hassles with letter to Santa; Yuletide Favorites!; Theft of painting shocks the artist; The birth of Christ-- What if it happened today?; WPCD Top 15 for the Week of Dec. 11; Ice storm turns Parkland into sparkling wonderland; Classifieds; Riding is fun...riding is costly!; Christ born in spring; 11 tie in contest; Loved Ones; Women basketball lose three in a row last week; Hartman resigns editorship; Fast Freddy Bowl Contest; PC basketball team holds 4-1 record Additional material: image Edition 2 literary magazinehttps://spark.parkland.edu/prospectus_1978/1000/thumbnail.jp

    Lumbar spine radiographic features and demographic, clinical, and radiographic knee, hip and hand osteoarthritis: The Johnston County Osteoarthritis Project

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    Objective—1) To determine the prevalence of lumbar spine individual radiographic features (IRF) of disc space narrowing (DSN), osteophytes (OST) and facet joint osteoarthritis (FOA). 2) To describe the frequencies of demographic, clinic and radiographic knee, hip and hand osteoarthritis (OA) across lumbar spine IRF. 3) To determine factors associated with lumbar spine IRF. Methods—A cross-sectional study of 840 participants enrolled in the Johnston County OA Project (2003-4). Sample-based prevalence estimates were generated for each lumbar spine IRF. Associations between lumbar spine IRF and demographic, clinical and peripheral joint OA were determined with logistic regression models. Results—Sample-based prevalence estimates were similar for DSN (57.6%) and FOA (57.9%) but higher for OST (88.1%) with significant differences across race and gender. Hand and knee OA frequencies increased across IRF whereas the effect was absent for hip OA. African Americans had lower odds of FOA (adjusted odds ratio [aOR]=0.45 (95% CI 0.32, 0.62)) while there was no racial association with DSN and OST. Low back symptoms were associated with DSN (aOR=1.37 (95% CI 1.04, 1.80)) but not OST or FOA. Knee OA was associated with OST (aOR=1.62 (95% CI 1.16, 2.27)) and FOA (aOR=1.69 (95% CI 1.15, 2.49)) but not DSN. Hand OA was associated with FOA (aOR=1.67 (95% CI 1.20, 2.28)) but not with DSN or OST. No associations were found with hip OA. Conclusion—These findings underscore the importance of analyzing lumbar spine IRF separately as the associations with demographic, clinic and radiographic knee, hip and hand OA differ widely

    Measuring the robustness of resource allocations for distributed domputer systems in a stochastic dynamic environment

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    Heterogeneous distributed computing systems often must function in an environment where system parameters are subject to variations during operation. Robustness can be defined as the degree to which a system can function correctly in the presence of parameter values different from those assumed. We present a methodology for quantifying the robustness of resource allocations in a dynamic environment where task execution times vary within predictable ranges and tasks arrive randomly. The methodology is evaluated through measuring the robustness of three different resource allocation heuristics within the context of the stochastically modeled dynamic environment. A Bayesian regression model is fit to the combined results of the three heuristics to demonstrate the correlation between the stochastic robustness metric and the presented performance metric. The correlation results demonstrated the significant potential of the stochastic robustness metric to predict the relative performance of the three heuristics given a common objective function

    Corporate Security Responsibility: Towards a Conceptual Framework for a Comparative Research Agenda

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    The political debate about the role of business in armed conflicts has increasingly raised expectations as to governance contributions by private corporations in the fields of conflict prevention, peace-keeping and postconflict peace-building. This political agenda seems far ahead of the research agenda, in which the negative image of business in conflicts, seen as fuelling, prolonging and taking commercial advantage of violent conflicts,still prevails. So far the scientific community has been reluctant to extend the scope of research on ‘corporate social responsibility’ to the area of security in general and to intra-state armed conflicts in particular. As a consequence, there is no basis from which systematic knowledge can be generated about the conditions and the extent to which private corporations can fulfil the role expected of them in the political discourse. The research on positive contributions of private corporations to security amounts to unconnected in-depth case studies of specific corporations in specific conflict settings. Given this state of research, we develop a framework for a comparative research agenda to address the question: Under which circumstances and to what extent can private corporations be expected to contribute to public security

    Gaussian Quantum Information

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    The science of quantum information has arisen over the last two decades centered on the manipulation of individual quanta of information, known as quantum bits or qubits. Quantum computers, quantum cryptography and quantum teleportation are among the most celebrated ideas that have emerged from this new field. It was realized later on that using continuous-variable quantum information carriers, instead of qubits, constitutes an extremely powerful alternative approach to quantum information processing. This review focuses on continuous-variable quantum information processes that rely on any combination of Gaussian states, Gaussian operations, and Gaussian measurements. Interestingly, such a restriction to the Gaussian realm comes with various benefits, since on the theoretical side, simple analytical tools are available and, on the experimental side, optical components effecting Gaussian processes are readily available in the laboratory. Yet, Gaussian quantum information processing opens the way to a wide variety of tasks and applications, including quantum communication, quantum cryptography, quantum computation, quantum teleportation, and quantum state and channel discrimination. This review reports on the state of the art in this field, ranging from the basic theoretical tools and landmark experimental realizations to the most recent successful developments.Comment: 51 pages, 7 figures, submitted to Reviews of Modern Physic
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