Utilização de energia solar para aplicações de resfriamento: uma revisão

Major portion of energy in the residential sector is consumed to provide the human comfort. The use of conventional energy resources creates the problem of global warming.  Due to severe impact of released gases on the environment, there is needed to use the alternative energy resources to maintain the human comfort zone. The use of different solar energy conversion techniques is making a promising contribution to provide the clean energy. The purpose of this study is to provide an overview of recent advancement in the use of solar energy to provide the indoor climate comfort. The use of non-concentrating and concentrating conversion techniques are investigated in detail. The study also discusses about the enticements of solar energy to attract the investment in the merger of solar energy and human comfort industries.La mayor parte de la energía en el sector residencial se consume para proporcionar el confort humano. El uso de recursos energéticos convencionales crea el problema del calentamiento global. Debido al severo impacto de los gases liberados en el medio ambiente, es necesario utilizar recursos energéticos alternativos para mantener la zona de confort humano. El uso de diferentes técnicas de conversión de energía solar está haciendo una contribución prometedora para proporcionar energía limpia. El propósito de este estudio es proporcionar una visión general de los avances recientes en el uso de la energía solar para proporcionar el confort climático interior. Se investiga en detalle el uso de técnicas de conversión no concentradoras y concentradoras. El estudio también analiza los incentivos de la energía solar para atraer inversiones en la fusión de las industrias de energía solar y comodidad humana.Grande parte da energia no setor residencial é consumida para proporcionar o conforto humano. O uso de recursos energéticos convencionais cria o problema do aquecimento global. Devido ao forte impacto dos gases liberados no meio ambiente, existe a necessidade de utilizar os recursos energéticos alternativos para manter a zona de conforto humano. O uso de diferentes técnicas de conversão de energia solar está dando uma contribuição promissora para fornecer energia limpa. O objetivo deste estudo é fornecer uma visão geral do avanço recente no uso da energia solar para proporcionar conforto climático interno. O uso de técnicas de conversão de não concentração e concentração é investigado em detalhes. O estudo também discute os atrativos da energia solar para atrair investimentos na fusão das indústrias de energia solar e conforto humano

Modelagem de materiais e estudo de falha de diferentes compósitos reforçados com fibras para vasos de pressão

Pressure vessels are essential industrial tools regarding storage of high-pressure fluids. Utilization of pressure vessels in ordinary industrial environment impose serious dangers to human life in case of failure. Manufacturing material and working pressure as per material’s strength are necessary arguments for a pressure vessel designer. In this study, five composite materials are selected to investigate the behavior of pressure vessels under high pressure. FEA technique is used to check stresses and deformations in different composite layers. Pressure applied to all materials models in this study is around 20 MPa. Tsai Wu and Maximum stress theories are used to study failure in first two composite layers of different composite materials. Glass Epoxy composites perform well in terms of static loading failure. They demonstrate reasonable strength without experiencing failure in the second layer. T300/976 composites are also suitable for the intended loading conditions of the model because did not exhibit second layer failure, making them a viable option. Therefore, it is recommended to use Glass/Epoxy and T300/976 composites in extreme pressure conditions such as those found in CNG cylinders. Three of the composite materials tested did not satisfy the failure theories. Hence, it is not safe to use them in extreme loading conditions. Although these materials did not show any failure in the first layer, deformations in the second layer made them susceptible to failure.Los recipientes a presión son herramientas industriales esenciales para el almacenamiento de fluidos a alta presión. La utilización de recipientes a presión en el entorno industrial ordinario impone serios peligros para la vida humana en caso de falla. El material de fabricación y la presión de trabajo según la resistencia del material son argumentos necesarios para un diseñador de recipientes a presión. En este estudio, se seleccionan cinco materiales compuestos para investigar el comportamiento de los recipientes a presión bajo alta presión. La técnica FEA se utiliza para comprobar tensiones y deformaciones en diferentes capas compuestas. La presión aplicada a todos los modelos de materiales en este estudio es de alrededor de 20 MPa. Las teorías de Tsai Wu y la tensión máxima se utilizan para estudiar la falla en las dos primeras capas compuestas de diferentes materiales compuestos. Los compuestos de epoxi de vidrio funcionan bien en términos de falla de carga estática. Demuestran una fuerza razonable sin experimentar fallas en la segunda capa. Los compuestos T300/976 también son adecuados para las condiciones de carga previstas del modelo porque no presentaron fallas en la segunda capa, lo que los convierte en una opción viable. Por lo tanto, se recomienda utilizar compuestos de vidrio/epoxi y T300/976 en condiciones de presión extrema, como las que se encuentran en los cilindros de GNC. Tres de los materiales compuestos probados no cumplieron con las teorías de falla. Por lo tanto, no es seguro usarlos en condiciones de carga extremas. Si bien estos materiales no presentaron falla alguna en la primera capa, las deformaciones en la segunda capa los hicieron susceptibles a la falla.Vasos de pressão são ferramentas industriais essenciais para o armazenamento de fluidos sob alta pressão. A utilização de vasos de pressão em ambiente industrial comum impõe sérios perigos à vida humana em caso de falha. O material de fabricação e a pressão de trabalho de acordo com a resistência do material são argumentos necessários para um projetista de vasos de pressão. Neste estudo, cinco materiais compósitos são selecionados para investigar o comportamento de vasos de pressão sob alta pressão. A técnica FEA é usada para verificar tensões e deformações em diferentes camadas compostas. A pressão aplicada a todos os modelos de materiais neste estudo é de cerca de 20 MPa. As teorias de Tsai Wu e tensão máxima são usadas para estudar a falha nas duas primeiras camadas compostas de diferentes materiais compostos. Os compósitos de vidro epóxi têm bom desempenho em termos de falha de carga estática. Eles demonstram resistência razoável sem sofrer falha na segunda camada. Os compósitos T300/976 também são adequados para as condições de carregamento pretendidas do modelo, pois não apresentaram falha na segunda camada, tornando-os uma opção viável. Portanto, recomenda-se a utilização dos compósitos Vidro/Epóxi e T300/976 em condições extremas de pressão como as encontradas em cilindros de GNV. Três dos materiais compósitos testados não satisfizeram as teorias de falha. Portanto, não é seguro usá-los em condições extremas de carregamento. Embora esses materiais não apresentassem nenhuma falha na primeira camada, as deformações na segunda camada os tornavam suscetíveis à falha

Search Engine Optimization Algorithms for Page Ranking: Comparative Study

Every second, the number of visitors increase day by day due to the fast growing of World Wide Web. Till this day there are more than 11.3 billion web pages in the World Wide Web. In the modern era of technology and advance computation, world page ranking become a common feature of modern retrieval system. However, any query in search engine will display both relevant and irrelevant data that can cause overhead to the search engine and will affect the page ranking process. A new optimization technique is needed to improve the existing search engine optimization in increasing the page ranking. This paper presents a comparative study of different page ranking algorithms for search engine optimization. Also it explores some improvements that are needed to overcome the current problem in this field. The simulation result’s analysis clearly shows that there is a need of new optimization technique. This new technique must reduce the complexity and user overhead by displaying only related data which will reduce overheading in search engine

Model farm services centers in Khyber Pakhtunkhwa: Evaluation and the way forward

The sub-national Government of Khyber Pakhtunkhwa in Pakistan enacted Farm Services Centers Act, 2014, to establish Model Farm Services Centers (MFSCs) and Farm Services Centers as “one stop-shop” based on public-private partnership principle to strengthen extension system. The aim of these Centers is to empower small farmers at a platform to enhance their knowledge and skills and availability of quality agricultural inputs as stipulated in Section 4(g) of the Act, 2014, that each FSC shall “purchase certified seed, fertilizers, animal husbandry services, quality veterinary heath care services and medicines, farm machinery, expertise and technology for provision to the members who are registered with the Centre on affordable rates in comparison to open market rates”. The objective is to improve rural livelihoods, and development of the rural economy

Influencing factors on the accuracy of local geoid model

Different modification methods and software programs were developed to obtain accurate local geoid models in the past two decades. The quantitative effect of the main factors on the accuracy of local geoid modeling is still ambiguous and has not been clearly diagnosed yet. This study presents efforts to find the most influential factors on the accuracy of the local geoid model, as well as the amount of each factor's effect quantitatively. The methodology covers extracting the quantitative characteristics of 16 articles regarding local geoid models of different countries. The Statistical Package of Social Sciences (SPSS) software formulated a strong multiple regression model of correlation coefficient r = 0.999 with a high significance coefficient of determination R2 = 0.997 and adjusted R2 = 0.98 for the required effective factors. Then, factor analysis is utilized to extract the dominant factors which include: accuracy of gravity data (40%), the density of gravity data (25%) (total gravity factors is 65%), the Digital Elevation Model (DEM) resolution (16%), the accuracy of GPS/leveling points (10%) and the area of the terrain of the country/state under the study (9%). These results of this study will assist in developing more accurate local geoid models

Use of Central Nervous System (CNS) Medicines in Aged Care Homes: A Systematic Review and Meta-Analysis

Background: Both old age and institutionalization in aged care homes come with a significant risk of developing several long-term mental and neurological disorders, but there has been no definitive meta-analysis of data from studies to determine the pooled estimate of central nervous system (CNS) medicines use in aged care homes. We conducted this systematic review to summarize the use of CNS drugs among aged care homes residents. Methods: MEDLINE, EMBASE, CINAHL, Scopus, and International Pharmaceutical Abstracts (IPA) databases were searched (between 1 January 2000 and 31 December 2018) to identify population-based studies that reported the use of CNS medicines in aged care homes. Pooled proportions (with 95% confidence interval), according to study location were calculated. Results: A total of 89 studies reported the use of CNS medicines use in aged care. The pooled estimate of CNS drugs use varied according to country (from 20.3% in Ireland to 49.0% in Belgium) and region (from 31.7% in North America to 42.5% in Scandinavia). The overall pooled estimate of psychotropic medicines use was highest in Europe (72.2%, 95% CI, 67.1–77.1%) and lowest in ANZ region (56.9%, 95% CI, 52.2–61.4%). The pooled estimate of benzodiazepines use varied widely from 18.9% in North America to 44.8% in Europe. The pooled estimate of antidepressants use from 47 studies was 38.3% (95% CI 35.1% to 41.6%) with highest proportion in North America (44.9%, 95% CI, 35.3–54.5%). Conclusion: The overall use of CNS drugs varied among countries, with studies from Australia-New Zealand reported the lowest use of CNS drugs. The criteria for prescribing CNS drugs in clinical practice should be evidence-based. The criteria should be used not to prohibit the use of the listed medications but to support the clinical judgement as well as patient safety

The Pakistan risk of myocardial infarction study: A resource for the study of genetic, lifestyle and other determinants of myocardial infarction in south Asia

The burden of coronary heart disease (CHD) is increasing at a greater rate in South Asia than in any other region globally, but there is little direct evidence about its determinants. The Pakistan Risk of Myocardial Infarction Study (PROMIS) is an epidemiological resource to enable reliable study of genetic, lifestyle and other determinants of CHD in South Asia. By March 2009, PROMIS had recruited over 5,000 cases of first-ever confirmed acute myocardial infarction (MI) and over 5,000 matched controls aged 30-80 years. For each participant, information has been recorded on demographic factors, lifestyle, medical and family history, anthropometry, and a 12-lead electrocardiogram. A range of biological samples has been collected and stored, including DNA, plasma, serum and whole blood. During its next stage, the study aims to expand recruitment to achieve a total of about 20,000 cases and about 20,000 controls, and, in subsets of participants, to enrich the resource by collection of monocytes, establishment of lymphoblastoid cell lines, and by resurveying participants. Measurements in progress include profiling of candidate biochemical factors, assay of 45,000 variants in 2,100 candidate genes, and a genomewide association scan of over 650,000 genetic markers. We have established a large epidemiological resource for CHD in South Asia. In parallel with its further expansion and enrichment, the PROMIS resource will be systematically harvested to help identify and evaluate genetic and other determinants of MI in South Asia. Findings from this study should advance scientific understanding and inform regionally appropriate disease prevention and control strategies

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial