2,669 research outputs found

    Life cycle environmental performance of material specification: a BIM-enhanced comparative assessment

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    This study aims to evaluate the extent to which building material specification affects life cycle environmental performance, using a building information modelling (BIM)-enhanced life cycle assessment (LCA) methodology. A combination of the BIM-based design and analysis tool Revit Architecture, the energy simulation tool Green Building Studio (GBS) and the LCA tool ATHENA Impact Estimator were used for the assessment. The LCA was carried out on a life case study of a 2100 m2 two-floor primary-school building, as well as a variability analysis, by varying the material specification in terms of whole building materials. The life cycle performance of the buildings was primarily evaluated in terms of its global warming potential (GWP) and health impact. The findings of the study show that irrespective of the materials used, buildings that are based on renewable energy perform better than those based on fossil fuels over their life cycle. In terms of building materials, both environmental and health preferences of buildings congruently range from timber, brick/block and steel to insulated concrete formwork (ICF), in descending order. The study suggests that as buildings become more energy efficient during operational stages, serious attention needs to be given to their embodied impact. The study lays out a methodological framework that could be adopted by industry practitioners in evaluating life cycle environmental impact of different BIM-modelled material options at the building conception stage. This has the tendency to ensure that the highest proportion of life cycle environmentally beneficial material combinations are selected during specification and construction

    Design and Implementation of Storage System Using Byte-index Chunking Scheme

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    In this paper, we present an enhanced storage system that supports Byte-index chunking algorithm. The storage system aims to provide efficient data deduplication with high performance and to be performed in rapid time. We describe the overall procedure of Byteindex chunking based storage system including read/write procedure and how the system works. The key idea of Byte-index chunking is to adapt fixed-size block chunk scheme which are distributed to “Index-table ” by chunk’s both side boundary values. We have found that Byte-index chunking in storage system provides high performance compared with other chunking schemes. Experiments result shows that the storage system with Byte-index chunking compresses overall data with high deduplication capability and reduce the speed of file processing

    Prevalence of allergic rhinitis and its associated morbidity in adults with asthma: A multicentre study

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    Objectives To assess the prevalence of allergic rhinitis in adult patients with asthma in Hong Kong, and to compare the morbidity endured by asthma patients with and without allergic rhinitis. Design Cross-sectional study. Setting Respiratory clinics of four major public hospitals in Hong Kong. Patients A total of 600 adults with asthma were recruited from March to May 2007. Main outcome measures Doctors and patients completed separate questionnaires evaluating symptoms, treatment, and health care utilisation. Spirometry data were obtained for a subgroup of patients at the time of survey completion. Results The patients consisted of 267 males and 333 females, with 251 having spirometry data. The mean pre-bronchodilator 1-second forced expiratory volume predicted among those who had spirometry performed was 88% (standard deviation, 28%). In all, 50% of the patients had intermittent and 50% had persistent asthma. Over three quarters (463/600; 77%) of patients had experienced allergic rhinitis symptoms in the past 12 months, of whom 96% had a previous diagnosis of allergic rhinitis. Asthmatics without allergic rhinitis symptoms had higher rates of visits to doctors, pharmacy visits, emergency department attendances, and hospitalisations for asthma than those with both conditions. Among subjects with asthma and allergic rhinitis, those taking nasal steroid (226/463; 49%) had lower rates of emergency department visits (13 vs 25%, P=0.002) and hospitalisations (7 vs 13%, P=0.045) for asthma than those who were not. Conclusion Allergic rhinitis is a common co-morbid condition of asthma in this hospital clinic cohort. Treatment of allergic rhinitis with intra-nasal steroid was associated with less health care utilisation for asthma.published_or_final_versio

    Acknowledgments

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    I present the last book of Volume 53, the last in a series of four print issues the University of Richmond Law Review publishes throughout the academic year. Our publications would not have been possible without those who generously dedicated their time to this organization. As those before me, I take these first few pages of this final book to offer my gratitude to those who have contributed to the successes of the Law Review

    Realization of giant magnetoelectricity in helimagnets

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    We show that low field magnetoelectric (ME) properties of helimagnets Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 can be efficiently tailored by Al-substitution level. As x increases, the critical magnetic field for switching electric polarization is systematically reduced from ~1 T down to ~1 mT, and the ME susceptibility is greatly enhanced to reach a giant value of 2.0 x 10^4 ps/m at an optimum x = 0.08. We find that control of nontrivial orbital moment in the octahedral Fe sites through the Al-substitution is crucial for fine tuning of magnetic anisotropy and obtaining the conspicuously improved ME characteristics

    Legal Issues in Educational Management in Nigeria

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    The interaction of issues of law and schooling are becoming morepronounced by the day as our society continues to witness significant and rapid socio-political and economic changes. In an age that is globally infused with the concern for individual rights, there is of recent an emergence of local court cases as a confrontation of school house authority. In Nigeria, this is a post-1970 phenomenon and discussion on the same in the academic literature is scanty. It is against this background that this paper discusses pertinent legal issues in educational management in the country.Keywords: Legal basis of education; Litigation; Management

    Crystallization and preliminary X-ray crystallographic analysis of a yedU gene product from Escherichia coli

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    A yedU gene product with a molecular mass of 31 kDa is a hypothetical protein with no known function. The protein was purified and crystallized at 296 K. X-ray diffraction data have been collected to 2.3 Angstrom using synchrotron radiation. The crystals belong to the primitive orthorhombic system, with unit-cell parameters a = 50.56, b = 63.45, c = 168.02 Angstrom. The asymmetric unit contains two monomers of the protein, with a corresponding V-M of 2.25 Angstrom(3) Da(-1) and a solvent content of 44.84%.open2

    Social disorganization and history of child sexual abuse against girls in sub-Saharan Africa : a multilevel analysis

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    Background: Child sexual abuse (CSA) is a considerable public health problem. Less focus has been paid to the role of community level factors associated with CSA. The aim of this study was to examine the association between neighbourhood-level measures of social disorganization and CSA. Methods: We applied multiple multilevel logistic regression analysis on Demographic and Health Survey data for 6,351 adolescents from six countries in sub-Saharan Africa between 2006 and 2008. Results: The percentage of adolescents that had experienced CSA ranged from 1.04% to 5.84%. There was a significant variation in the odds of reporting CSA across the communities, suggesting 18% of the variation in CSA could be attributed to community level factors. Respondents currently employed were more likely to have reported CSA than those who were unemployed (odds ratio [OR] = 2.05, 95% confidence interval [CI] 1.48 to 2.83). Respondents from communities with a high family disruption rate were 57% more likely to have reported CSA (OR=1.57, 95% CI 1.14 to 2.16). Conclusion: We found that exposure to CSA was associated with high community level of family disruption, thus suggesting that neighbourhoods may indeed have significant important effects on exposure to CSA. Further studies are needed to explore pathways that connect the individual and neighbourhood levels, that is, means through which deleterious neighbourhood effects are transmitted to individuals
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