206 research outputs found

    Numerical Study of the Thermal Efficiency of a School Building with Complex Topology for Different Orientations

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    In this work a numerical model that simulates the thermal behavior of a building with complex topology and evaluates the indoor thermal and air quality, in transient conditions, is used for a school building thermal project. The program calculates the building surfaces solar radiation field, the building's temperatures, the internal environmental variables, and the occupant's comfort levels. Initially, after the numerical model is validated, the software is used to evaluate the school building's thermal response for four different orientations, either in winter or summer conditions. The work then aims to identify uncomfortable spaces in order to propose, as an example, several solutions that could be introduced for each orientation, that would improve the thermal comfort and air quality levels to which the occupants are subjected, and decrease the building's energy consumption levels. The information obtained from this study could be used to help a designer choose which thermal systems and solutions function best for a preferred school building orientation

    Assessment of Selected Physico Chemical Properties of Soil for Site Suitability for Waste Disposal in Abakaliki, Southeast, Nigeria

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    An assessment of the physicochemical properties of soil for site waste disposal was carried out in Abakaliki urban, southeastern Nigeria. Three sites namely: Waterworks road (WR), Hill top (HT) and Azuiyiokwu (AZ) were randomly selected. Soil samples were collected from 0-15 cm and 15-30 cm depths from the sites. The soil samples were analyzed for physicochemical properties. The results showed variations in soil properties of the three sites which indicate suitability of the different sites or otherwise for waste disposal. The relationship between  percent sand  moisture content on dry mass basis and total porosity was generally highly significant (P>0.01). Similarly, the relationship between percent sand and saturated hydraulic conductivity was also highly significant. Available P highly correlated with total porosity and saturated hydraulic conductivity. The sites with high sand percentage are good for refuse disposal while the ones with high clay percentage have problems of water logging and  build up of pollution for ground water. Dumpsites Water works road (WR) and Hilltop (HT) are better for waste disposal than dumpsite Azuiyiokwu (AZ). Keywords: Dumpsites, physicochemical, refuse, soil

    High-resolution X-ray Spectra Of The Symbiotic Star SS73 17

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    SS73 17 was an innocuous Mira-type symbiotic star until Integral and Swift discovered its bright hard X-ray emission, adding it to the small class of "hard X-ray emitting symbiotics." Suzaku observations in 2006 then showed it emits three bright iron lines as well, with little to no emission in the 0.3-2 keV bandpass. We present here followup observations with the Chandra HETG and Suzaku that confirm the earlier detection of strong emission lines of Fe Kalpha fluorescence, Fe XXV and Fe XXVI but also show significantly more soft X-ray emission. The high resolution spectrum also shows emission lines of other highly ionized ions as Si XIV and possibly S XVI. In addition, a reanalysis of the 2006 Suzaku data using the latest calibration shows that the hard (15-50 keV) X-ray emission is brighter than previously thought and remains constant in both the 2006 and 2008 data. The G ratio calculated from the Fe XXV lines shows that these lines are thermal, not photoionized, in origin. With the exception of the hard X-ray emission, the spectra from both epochs can be fit using thermal radiation assuming a differential emission measure based on a cooling flow model combined with a full and partial absorber. We show that acceptable fits can be obtained for all the data in the 1-10 keV band varying only the partial absorber. Based on the temperature and accretion rate, the thermal emission appears to be arising from the boundary layer between the accreting white dwarf and the accretion disk.Comment: 7 pages, 5 figures. Accepted by the Astrophysical Journa

    Microbiological safety assessment of food handlers in Wudil Local Government Area of Kano State, Nigeria

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    This study was conducted to investigate the bacteriological safety levels of food handlers in Wudil Local Government Area (LGA) of Kano State, Nigeria. A total of 200 hand-swab samples were collected from different male [100 (50%)] and female [100 (50%)] food handlers/peddlers in the study area. From these samples, 200 non-duplicate bacterial isolates consisting of strains of Salmonella typhi [60 (30%)], Salmonella choleraesuis [52 (26%)], Proteus mirabilis [10 (5%)], Morganella morganii [10 (5%)], Pseudomonas aeruginosa [10 (5%)], Escherichia coli [18 (9%)] and Staphylococcus aureus [40 (20%)] were isolated. A significant proportion (33.3%) of the food handlers sampled was children within the age range of 8-12 years. In addition, only 33.5% of the food handlers had basic level of primary education and a majority (96.5%) of the food handlers displayed poor levels of personal hygiene, especially with regards to safe food handling. S. typhi, S. cholaeresius and S. aureus were found to be the common bacterial species that colonized the hands of food handlers/peddlers in Wudil LGA, Kano State. This highlights a lack of food safety and the resulting risk of spreading foodborne diseases in the area. In addition, low literacy levels and lack of safe food handling practices contribute to the prevalence of these pathogens among the food handlers. It is important for food handlers to obtain training on safe food practices, undergo periodic health checks and practice proper hand hygiene. DOI: http://dx.doi.org/10.5281/zenodo.381334

    A survey on exposure-response relationships for road, rail, and aircraft noise annoyance: differences between continuous and intermittent noise

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    The aim of the present study is to establish exposure-response relationships reflecting the percentage highly annoyed (%HA) as functions of road traffic, railway, and aircraft noise exposure, measured as day-evening-night level (Lden), as well as to elucidate the degree to which the acoustic indicator Intermittency Ratio (IR), which reflects the "eventfulness" of a noise situation, predicts noise annoyance. We conducted a mixed-mode representative population survey in a stratified random sample of 5592 residents exposed to transportation noise all over Switzerland. Source-specific noise exposure was calculated for each floor and each façade based on comprehensive traffic data. Noise annoyance was measured using the ICBEN 11-point scale. The survey was carried out in 4 waves at different times of the year. We hypothesized that in addition to Lden, the effects of noise on annoyance can be better explained when also considering the intensity of short-term variations of noise level over time. We therefore incorporated the acoustic indicator IR in the statistical models. For all noise sources, results revealed significant associations between Lden and %HA after controlling for confounders and independent predictors such as IR (measured over 24 h), exposure to other transportation noise sources, sex and age, language, home ownership, education level, living duration, temperature, and access to a quiet side of the dwelling. Aircraft noise annoyance scored markedly higher than annoyance to railway and road traffic noise at the same Lden level. Railway noise elicited higher percentages of highly annoyed persons than road traffic noise. Results furthermore suggest that for road traffic noise, IR has an additional effect on %HA and can explain shifts of the exposure-response curve of up to about 6 dB between low IR and high IR exposure situations, possibly due to the effect of different durations of noise-free intervals between events. For railway and aircraft noise annoyance, the predictive value of IR was limited

    Output-based assessment of herd-level freedom from infection in endemic situations:Application of a Bayesian Hidden Markov model

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    International audienceCountries have implemented control programmes (CPs) for cattle diseases such as bovine viral diarrhoea virus (BVDV) that are tailored to each country-specific situation. Practical methods are needed to assess the output of these CPs in terms of the confidence of freedom from infection that is achieved. As part of the STOC free project, a Bayesian Hidden Markov model was developed, called STOC free model, to estimate the probability of infection at herd-level. In the current study, the STOC free model was applied to BVDV field data in four study regions, from CPs based on ear notch samples. The aim of this study was to estimate the probability of herd-level freedom from BVDV in regions that are not (yet) free. We additionally evaluated the sensitivity of the parameter estimates and predicted probabilities of freedom to the prior distributions for the different model parameters. First, default priors were used in the model to enable comparison of model outputs between study regions. Thereafter, country-specific priors based on expert opinion or historical data were used in the model, to study the influence of the priors on the results and to obtain country-specific estimates.The STOC free model calculates a posterior value for the model parameters (e.g. herd-level test sensitivity and specificity, probability of introduction of infection) and a predicted probability of infection. The probability of freedom from infection was computed as one minus the probability of infection. For dairy herds that were considered free from infection within their own CP, the predicted probabilities of freedom were very high for all study regions ranging from 0.98 to 1.00, regardless of the use of default or country-specific priors. The priors did have more influence on two of the model parameters, herd-level sensitivity and the probability of remaining infected, due to the low prevalence and incidence of BVDV in the study regions. The advantage of STOC free model compared to scenario tree modelling, the reference method, is that actual data from the CP can be used and estimates are easily updated when new data becomes availabl

    Stakeholder-driven transformative adaptation is needed for climate-smart nutrition security in sub-Saharan Africa - author correction

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    oai:repository.rothamsted.ac.uk:99048Improving nutrition security in sub-Saharan Africa under increasing climate risks and population growth requires a strong and contextualized evidence base. Yet, to date, few studies have assessed climate-smart agriculture and nutrition security simultaneously. Here we use an integrated assessment framework (iFEED) to explore stakeholder-driven scenarios of food system transformation towards climate-smart nutrition security in Malawi, South Africa, Tanzania and Zambia. iFEED translates climate–food–emissions modelling into policy-relevant information using model output implication statements. Results show that diversifying agricultural production towards more micronutrient-rich foods is necessary to achieve an adequate population-level nutrient supply by mid-century. Agricultural areas must expand unless unprecedented rapid yield improvements are achieved. While these transformations are challenging to accomplish and often associated with increased greenhouse gas emissions, the alternative for a nutrition-secure future is to rely increasingly on imports, which would outsource emissions and be economically and politically challenging given the large import increases required

    Permanence, Temporality and the Rhythms of Life : Exploring Significance of the Village Arena in Igbo Culture

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    The village arena (or ‘square’ or ‘Otobo’ in Nsukka Igbo) is at the physical and socio-cultural centre of Igbo life, in southeast Nigeria. It is a space where intangible Igbo cultural heritage is played out, and also serves as a virtual museum where heritage materials are kept. The arena performs its roles in two very different ways: as a sacred space hosting initiation rites and religious rituals; and as a profane space for meetings and ceremonies. Either way, these uses see the arena transition between permanency and temporality, following routines and rhythms which themselves give the practices meaning and significance, and contribute to their inscription on the landscape. This paper explores the complexities associated with these village arenas with a particular focus on their socio-cultural, political, economic and religious functions through time, as well as the way those complexities are manifest in material cultures that serve to characterize the village arena

    Current Treatment of Endolymphatic Sac Tumor of the Temporal Bone

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    An endolymphatic sac tumor (ELST) is a rare, indolent but locally aggressive tumor arising in the posterior petrous ridge. Patients present with sensorineural hearing loss and tinnitus. As the tumor progresses, patients may experience vertigo, ataxia, facial nerve paresis, pain and otorrhea. Most patients present in their 4th or 5th decade with a wide age range. Patients with von Hippel–Lindau disease have an increased likelihood of developing ELST. Histologically, ELST is a low-grade adenocarcinoma. As it progresses, it destroys bone and extends into adjacent tissues. The likelihood of regional or distant metastases is remote. The optimal treatment is resection with negative margins. Patients with positive margins, gross residual disease, or unresectable tumor are treated with radiotherapy or radiosurgery. Late recurrences are common, so long follow-up is necessary to assess efficacy. The likelihood of cure depends on tumor extent and is probably in the range of 50–75%

    Traumatic physical health consequences of intimate partner violence against women: what is the role of community-level factors?

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    <p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV) against women is a serious public health issue with recognizable direct health consequences. This study assessed the association between IPV and traumatic physical health consequences on women in Nigeria, given that communities exert significant influence on the individuals that are embedded within them, with the nature of influence varying between communities.</p> <p>Methods</p> <p>Cross-sectional nationally-representative data of women aged 15 - 49 years in the 2008 Nigeria Demographic and Health Survey was used in this study. Multilevel logistic regression analysis was used to assess the association between IPV and several forms of physical health consequences.</p> <p>Results</p> <p>Bruises were the most common form of traumatic physical health consequences. In the adjusted models, the likelihood of sustaining bruises (OR = 1.91, 95% CI = 1.05 - 3.46), wounds (OR = 2.54, 95% CI = 1.31 - 4.95), and severe burns (OR = 3.20, 95% CI = 1.63 - 6.28) was significantly higher for women exposed to IPV compared to those not exposed to IPV. However, after adjusting for individual- and community-level factors, women with husbands/partners with controlling behavior, those with primary or no education, and those resident in communities with high tolerance for wife beating had a higher likelihood of experiencing IPV, whilst mean community-level education and women 24 years or younger were at lower likelihood of experiencing IPV.</p> <p>Conclusions</p> <p>Evidence from this study shows that exposure to IPV is associated with increased likelihood of traumatic physical consequences for women in Nigeria. Education and justification of wife beating were significant community-level factors associated with traumatic physical consequences, suggesting the importance of increasing women's levels of education and changing community norms that justify controlling behavior and IPV.</p
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