1,530 research outputs found

    Analysis of the convergence of the 1/t and Wang-Landau algorithms in the calculation of multidimensional integrals

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    In this communication, the convergence of the 1/t and Wang - Landau algorithms in the calculation of multidimensional numerical integrals is analyzed. Both simulation methods are applied to a wide variety of integrals without restrictions in one, two and higher dimensions. The errors between the exact and the calculated values of the integral are obtained and the efficiency and accuracy of the methods are determined by their dynamical behavior. The comparison between both methods and the simple sampling Monte Carlo method is also reported. It is observed that the time dependence of the errors calculated with 1/t algorithm goes as N^{-1/2} (with N the MC trials) in quantitative agreement with the simple sampling Monte Carlo method. It is also showed that the error for the Wang - Landau algorithm saturates in time evidencing the non-convergence of the methods. The sources for the error are also determined.Comment: 8 pages, 5 figure

    The hospital discharge game : A game theory-inspired workshop to encourage cooperation between health and social care organisations

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    Traditionally, health and social care organisations have operated independently, with minimal interaction and poor integration of the various services with which a patient comes into contact. In some cases, 'perverse' systemic incentives have discouraged cooperation and led to a 'silo mentality'. In this paper, we present an interactive workshop game that can be played with those working in and around health and social care. The game places teams in the roles of community and acute hospitals, and asks them to make discharge decisions about patients. However, a 'perverse' incentive is present in the system, and opposing teams are not allowed to communicate, which leads to increasingly 'selfish' decision making. We outline the details of this game, and show how it can be used as a tool to facilitate understanding of the benefits of cross-organisational communication and cooperation. We also present data from an initial pilot of this workshop.National Institute for Health Research (NIHR

    Novel fiber-reinforced composite materials based on sustainable geopolymer matrix

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    Geopolymers are representing the most promising green and eco-friendly alternative to ordinary Portland cement and cementitious materials, thanks to their proven durability, mechanical and thermal properties. However, despite these features, the poor tensile and bending strengths usually exhibited by geopolymers due to their brittle and ceramic-like nature, can easily lead to catastrophic failure and represent the main drawback limiting the use of those materials in several applications. Fiber reinforced geopolymer composites may be considered a solution to improve flexural strength and fracture toughness. Different types of dispersed short fibers are here investigated as a reinforcing fraction for a geopolymer matrix based on an alkali-activated ladle-slag. It has been demonstrated that both organic and inorganic fibers can lead to a significant flexural strength enhancement. Moreover, the investigated geopolymers exhibit an increase in toughness, thus determining a switch from a brittle failure mode to a more ductile one

    A Large Cross-Sectional Community-Based Study of Newborn Care Practices in Southern Tanzania

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    Despite recent improvements in child survival in sub-Saharan Africa, neonatal mortality rates remain largely unchanged. This study aimed to determine the frequency of delivery and newborn-care practices in southern Tanzania, where neonatal mortality is higher than the national average. All households in five districts of Southern Tanzania were approached to participate. Of 213,220 female residents aged 13-49 years, 92% participated. Cross-sectional, retrospective data on childbirth and newborn care practices were collected from 22,243 female respondents who had delivered a live baby in the preceding year. Health facility deliveries accounted for 41% of births, with nearly all non-facility deliveries occurring at home (57% of deliveries). Skilled attendants assisted 40% of births. Over half of women reported drying the baby and over a third reported wrapping the baby within 5 minutes of delivery. The majority of mothers delivering at home reported that they had made preparations for delivery, including buying soap (84%) and preparing a cloth for drying the child (85%). Although 95% of these women reported that the cord was cut with a clean razor blade, only half reported that it was tied with a clean thread. Furthermore, out of all respondents 10% reported that their baby was dipped in cold water immediately after delivery, around two-thirds reported bathing their babies within 6 hours of delivery, and 28% reported putting something on the cord to help it dry. Skin-to-skin contact between mother and baby after delivery was rarely practiced. Although 83% of women breastfed within 24 hours of delivery, only 18% did so within an hour. Fewer than half of women exclusively breastfed in the three days after delivery. The findings suggest a need to promote and facilitate health facility deliveries, hygienic delivery practices for home births, delayed bathing and immediate and exclusive breastfeeding in Southern Tanzania to improve newborn health

    Are fluid inclusions in gypsum reliable paleoenvironmental indicators? An assessment of the evidence from the Messinian evaporites

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    The paleosalinity of water from which the gypsum precipitated during the Messinian salinity crisis is a controversial issue. Recent microthermometry studies on primary fluid inclusions in gypsum provided very low salinity values not compatible with precipitation from seawater, and suggested strong mixing between seawater and nonmarine waters enriched in calcium sulfate. We applied a new microthermometric protocol on gypsum crystals from nine Mediterranean sections that were experimentally stretched to measure a larger population of fluid inclusions. The results show salinities ranging from 9 to 238 wt‰ NaCl equivalent, largely falling within the evaporation path of normal seawater. The data from previous studies were obtained mostly from those fluid inclusions capable of nucleating a stable bubble after a weak stretching, which probably correspond to those having a lower salinity acquired through post-depositional crack-and-seal processes. Our data suggest instead that the primary gypsum precipitated from a marine brine, later modified by post-trapping processes during tectonics and exhumation

    THE CHORÁ OF PATMOS (GREECE): ANALYSIS OF ARCHITECTURAL HERITAGE, IDENTIFICATION OF RISKS AND ASSESSMENT OF IMPACTS

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    Abstract. The Historic Center (Chorá) of Patmos, located in one of the Dodecanese Islands of Greece, was inscribed in the World Heritage List in 1999. The morphological feature, the housing typologies and the building techniques that characterize the Chorá provide an authentic and astonishing expression of the stylistic and typological models of the vernacular architecture of the Greek islands. This paper presents part of the research carried out on the Chorá of Patmos, within the 3D Past project, funded by the European Creative Europe program. The first part illustrates the results of the research concerning the analysis of the material components of the architectural heritage of Patmos: the urban structure, the evolution of the main architectural typologies, the feature of the main building systems. The second part of the paper presents the application of the Heritage Impact Assessment (HIA), a tool for the management of site transformations and in particular for identifying, forecasting and evaluating the impact of potential development on the Outstanding Universal Value (OUV) of the properties. In the case of Patmos the application of HIA can provide an important contribution to manage changes and future transformations in order to preserve the cultural significance of the site and ensure its sustainable development
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