1,187 research outputs found
Distributed storage manager system for synchronized and scalable AV services across networks
This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Hindawi Publishing CorporationThis paper provides an innovative solution, namely, the distributed storage manager that opens a new path for highly interactive and personalized services. The distributed storage manager provides an enhancement to the MHP storage management functionality acting as a value added middleware distributed across the network. The distributed storage manager system provides multiple protocol support for initializing and downloading both streamed and file-based content and provides optimum control mechanisms to organize the storing and retrieval of content that are remained accessible to other multiple heterogeneous devices
TECHNO-ECONOMIC INVESTIGATION OF DIFFERENT ALTERNATIVES OF IMPROVING SIMPLE GAS TURBINE INTEGRATION OPTIONS
This study investigated the effect of integrating various models proposed to improve a simple gas turbine power plant. A computer program was developed in Matlab software was used to simulate the performance parameters. The energy and exergy analysis of the plant was carried out. The energy and exergy analysis result revealed that both energy and exergy efficiency of plant is low as a result three improvement options were considered. They include Model 1: reducing inlet air cooling (IAC) of the compressor by using the wasted energy in the natural gas pressure drop station. Model 2: recovering wasted energy in the exhaust through heat recovery steam generator (HRSG) and injecting steam into the combustion chamber and lastly Model 3: by combining the two methods. The result showed that among the three methods of improving the plant investigated Model 3 was found to boost power output of the plant from 28.3 MW to 78.4 MW while the thermal and exergetic efficiency improved by 25.5 and 23.6% respectively. Furthermore, from economic and environmental point of view, the lowest levelized cost of electricity as well as the specific emissions was observed in Model 3. Consequently, Model 3 is selected as the best option in improving the simple gas turbine. Â http://dx.doi.org/10.4314/njt.v36i3.2
Exergetic Modelling of Oil-Fired Steam Boilers
The performance variables and potential for energy savings in oil-fired industrial steam boilers were studied. Operational parameters of steam boilers using low pour fuel oil (LPFO) and diesel were used to determine thermodynamic properties of material streams and exergetic parameters. Analysis of thermodynamic properties on exergetic performance of boilers was conducted. Exergetic models developed are also presented. The ratio of the energy to exergy efficiencies of the heat exchanging unit and of the entire steam boiler was determined as 1.4 and 1.8614 respectively. The average overall boiler exergy destruction decreased by 14.62%, as the evaporation ratio increased from 10 to 14 though heat loss in boiler was found to increase with increases in evaporation ratio. Developed models in this study could be employed to analyse and estimate exergetic performance indices of oil-fired steam boilers in order to enhance their efficiencies and reduce energy wastage.http://dx.doi.org/10.4314/njt.v33i4.1
SHOPPING MALL AIR DISTRIBUTION SYSTEM
The objective to design Heating, Ventilation & Air conditioning (HVAC) system for a commercial Building, with simultaneously controls its temperature, humidity, cleanliness, proper distribution, noise level, heat load calculation, fresh air, exhaust, duct design, pipe design, equipment selection and layout of accessories such as indoor and outdoor unit of the project. Cooling load will be calculated on E20 form. Indeed, today the emphasis is no more on understanding air conditioning ‘products’ but on creating ‘solutions’ and not just solutions, but ‘customized solutions’ that suit specific cooling needs of specific business and establishment
The state of ambient air quality in Pakistan—a review
Background and purpose: Pakistan, during the last decade, has seen an extensive escalation in population growth, urbanization, and industrialization, together with a great increase in motorization and energy use. As a result, a substantial rise has taken place in the types and number of emission sources of various air pollutants. However, due to the lack of air quality management capabilities, the country is suffering from deterioration of air quality. Evidence from various governmental organizations and international bodies has indicated that air pollution is a significant risk to the environment, quality of life, and health of the population. The Government has taken positive steps toward air quality management in the form of the Pakistan Clean Air Program and has recently established a small number of continuous monitoring stations. However, ambient air quality standards have not yet been established. This paper reviews the data being available on the criteria air pollutants: particulate matter (PM), sulfur dioxide, ozone, carbon monoxide, nitrogen dioxide, and lead. Methods: Air pollution studies in Pakistan published in both scientific journals and by the Government have been reviewed and the reported concentrations of PM, SO2, O3, CO, NO2, and Pb collated. A comparison of the levels of these air pollutants with the World Health Organization air quality guidelines was carried out. Results: Particulate matter was the most serious air pollutant in the country. NO2 has emerged as the second high-risk pollutant. The reported levels of PM, SO2, CO, NO2, and Pb were many times higher than the World Health Organization air quality guidelines. Only O3 concentrations were below the guidelines. Conclusions: The current state of air quality calls for immediate action to tackle the poor air quality. The establishment of ambient air quality standards, an extension of the continuous monitoring sites, and the development of emission control strategies are essential. © Springer-Verlag 2009
Prevalence and demographics of anxiety disorders: a snapshot from a community health centre in Pakistan
<p>Abstract</p> <p>Background</p> <p>The developing world is faced with a high burden of anxiety disorders. The exact prevalence of anxiety disorders in Pakistan is not known. There is a need to develop an evidence base to aid policy development on tackling anxiety and depressive disorders in the country. This is the first pilot study to address the prevalence of anxiety disorders and their association with sociodemographic factors in Pakistan.</p> <p>Methods</p> <p>A cross-sectional study was conducted among people visiting Aga Khan University Hospital (AKUH), a tertiary care facility in Karachi, Pakistan. The point prevalence of anxiety amongst the sample population, which comprised of patients and their attendants, excluding all health care personnel, was assessed using the validated Urdu version of the Hospital Anxiety and Depression Scale (HADS). The questionnaire was administered to 423 people. Descriptive statistics were performed for mean scores and proportions.</p> <p>Results</p> <p>The mean anxiety score of the population was 5.7 ± 3.86. About 28.3% had borderline or pathological anxiety. The factors found to be independently predicted with anxiety were, female sex (odds ratio (OR) = 2.14, 95% CI 1.36–3.36, p = 0.01); physical illness (OR = 1.67, 95% CI 1.06–2.64, p = 0.026); and psychiatric illness (OR = 1.176, 95% CI 1.0–3.1, p = 0.048). In the final multivariate model, female sex (adjusted odds ratio (AOR) = 2, 95% CI 1.28–3.22) and physical illness (AOR = 1.56, 95% CI 0.97–2.48) were found to be significant.</p> <p>Conclusion</p> <p>Further studies via nationally representative surveys need to be undertaken to fully grasp the scope of this emerging public health issue in Pakistan.</p
Does left atrial volume affect exercise capacity of heart transplant recipients?
<p>Abstract</p> <p>Background</p> <p>Heart transplant (HT) recipients demonstrate limited exercise capacity compared to normal patients, very likely for multiple reasons. In this study we hypothesized that left atrial volume (LAV), which is known to predict exercise capacity in patients with various cardiac pathologies including heart failure and hypertrophic cardiomyopathy is associated with limited exercise capacity of HT recipients.</p> <p>Methods</p> <p>We analyzed 50 patients [age 57 ±2 (SEM), 12 females] who had a post-HT echocardiography and cardiopulmonary exercise test (CPX) within 9 weeks time at clinic follow up. The change in LAV (ΔLAV) was also computed as the difference in LAV from the preceding one-year to the study echocardiogram. Correlations among the measured parameters were assessed with a Pearson's correlation analysis.</p> <p>Results</p> <p>LAV (n = 50) and ΔLAV (n = 40) indexed to body surface area were 40.6 ± 11.5 ml·m<sup>-2 </sup>and 1.9 ± 8.5 ml·m<sup>-2·</sup>year<sup>-1</sup>, data are mean ± SD, respectively. Indexed LAV and ΔLAV were both significantly correlated with the ventilatory efficiency, assessed by the VE/VCO<sub>2 </sub>slope (r = 0.300, p = 0.038; r = 0.484, p = 0.002, respectively). LAV showed a significant correlation with peak oxygen consumption (r = -0.328, p = 0.020).</p> <p>Conclusions</p> <p>Although our study is limited by a retrospective study design and relatively small number of patients, our findings suggest that enlarged LAV and increasing change in LAV is associated with the diminished exercise capacity in HT recipients and warrants further investigation to better elucidate this relationship.</p
Pyrolysis/reforming of rice husks with a Ni–dolomite catalyst: Influence of process conditions on syngas and hydrogen yield
Recent advances and perspectives on starch nanocomposites for packaging applications
Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites
Cell‐ and Gene‐Based Therapeutic Strategies for Periodontal Regenerative Medicine
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142086/1/jper1223.pd
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