87 research outputs found
How to pave the way for greater energy cooperation in the GCC
Energy cooperation among member states of the GCC states could pave the way for further integration to increase economic efficiency, harmonise policies, improve governance and ensure security of supply. The region is facing a rapid increase in domestic energy demand as economic growth, coupled with large infrastructure and industrial projects, as well as population growth and immigration (total population jumped from 23 million in 1990 to 53 million in 2015), drive up electricity and fuel consumption. Additionally, such cooperation would create an even stronger regional bloc in the global oil market (that currently exists, to some extent, through OPEC)
Anti Chlamydial Antibodies in Women with Ectopic Pregnancy
Background: To compare the frequency of chlamydia trachomatis infection in women with ectopic and with normal pregnancies.Methods: In this case-control study diagnosed patients of ectopic pregnancy(EP)were included . The control group comprised of early normal intra uterine pregnancies (1st trimester). A total number of 88, comprising 44 cases and 44 controls were included in this study. Sera from patients was drawn at the time of operation or within the subsequent 24 hours. Anti-chlamydial IgG was performed by ELISA.Results: Sampled cases population (n=44) had mean age distribution 26.48 years while among controls, mean age was 25.32 years. Presenting symptoms of cases showed pelvic pain (54.5%), bleeding (27.3%), vomiting (11.4%) and burning micturition (6.8%). During contraceptive practices , out of 88 patients, 5 cases and 20 controls gave history of safe sex practices. Out of 63 patients, who did not give history of any contraceptive practice, Anti-Chlamydia IgG was detected in 11 cases and 5 controls. Regarding Anti-Chlamydia IgG distribution among cases and controls, IgG was detected in 11(25%) cases and in 5(11.3%) controls.Conclusion: Frequency of anti-chlamydial IgG antibodies was much higher in women with ectopic pregnancy (25%) as compared to healthy controls(11.3%)
Effect of dynamic injection pressure on performance, emission and combustion characteristics of a compression ignition engine
Diesel engine emissions produced during burning of fossil fuel are extremely accountable for numerous serious problems. In order to lessen these emissions, performance of diesel engine needs to be improved. Fuel injection pressure is one of the operating parameters that affects the performance and emissions of a diesel engine which has been reported in this review paper. Decrease in injection pressure results in inferior combustion which leads to increase in BSFC and decrease in BTE. Injection pressure increase results in better mixing of air and fuel. As a result, combustion improves which leads to reduced BSFC and increased BTE. Due to superior air–fuel mixture resulting from increase in injection pressure, CO and HC emission decreases. Also, exhaust gas temperature decreases too. Increase in injection pressure results in increased heat release rate which leads increase in NOx emission. Literatures reports that, increasing the injection pressure results in up to 18% and 9% reduction of BSFC and EGT. Furthermore, it is possible to achieve more than 50% CO and HC and 28% NOx emission reduction by increasing the fuel injection pressure
Effect of dynamic injection pressure on performance, emission and combustion characteristics of a compression ignition engine
Diesel engine emissions produced during burning of fossil fuel are extremely accountable for numerous serious problems. In order to lessen these emissions, performance of diesel engine needs to be improved. Fuel injection pressure is one of the operating parameters that affects the performance and emissions of a diesel engine which has been reported in this review paper. Decrease in injection pressure results in inferior combustion which leads to increase in BSFC and decrease in BTE. Injection pressure increase results in better mixing of air and fuel. As a result, combustion improves which leads to reduced BSFC and increased BTE. Due to superior air-fuel mixture resulting from increase in injection pressure, CO and HC emission decreases. Also, exhaust gas temperature decreases too. Increase in injection pressure results in increased heat release rate which leads increase in NO emission. Literatures reports that, increasing the injection pressure results in up to 18% and 9% reduction of BSFC and EGT. Furthermore, it is possible to achieve more than 50% CO and HC and 28% NOx emission reduction by increasing the fuel injection pressure. (C) 2015 Elsevier Ltd. All rights reserved
Engine combustion, performance and emission characteristics of gas to liquid (GTL) fuels and its blends with diesel and bio-diesel
Crude oil price hikes, energy security concerns and environmental drivers have turned the focus to alternative fuels. Gas to liquid (GTL) diesel is regarded as a promising alternative diesel fuel, considering the adeptness to use directly as a diesel fuel or in blends with petroleum-derived diesel or bio-diesel. GTL fuel derived from Fischer-Tropsch synthesis is of distinctly different characteristics than fossil diesel fuel due to its paraffinic nature, virtually zero sulfur, low aromatic contents and very high cetane number. GTL fuel is referred to as a “clean fuel” for its inherent ability to reduce engine exhaust emission even with blends of diesel and bio-diesel. This paper illustrates feasibility of GTL fuel in context of comparative fuel properties with conventional diesel and bio-diesels. This review also describes the technical attributes of GTL and its blends with diesel and bio-diesel focusing their impact on engine performance and emission characteristics on the basis of the previous research works. It can introduce an efficacious guideline to devise several blends of alternative fuels, further the development of engine performance and constrain exhaust emission to cope with the relentless efforts to manufacture efficient and environment friendly powertrains
Effect of idling on fuel consumption and emissions of a diesel engine fueled by Jatropha biodiesel blends
An engine running at low load and low rated speed is said to be subject to high idling conditions, a mode which represents one of the major problems currently the transport industry is facing. During this time, the engine can not work at peak operating temperature. This leads to incomplete combustion and emissions level increase due to having fuel residues in the exhaust. Also, idling results in increase in fuel consumption. The purpose of this study is to evaluate fuel consumption and emissions parameters under high idling conditions when diesel blended with Jatropha curcas biodiesel is used to operate a diesel engine. Although biodiesel diesel blends decrease carbon monoxide and hydrocarbon emissions, they increase nitrogen oxides emissions in high idling modes. Compared to pure diesel fuel, fuel consumption also increases under all high idling conditions for biodiesel -diesel blends, with a further increase occurring as blend percentage rises
Influence of engine operating variable on combustion to reduce exhaust emissions using various biodiesels blend
This study focused mainly on the behavior of biodiesel operated under various operating conditions. The experiment was conducted with B20 of three potential biodiesel sources, namely, rice bran, Moringa and sesame oil. A significant outcome was observed from the test results, which showed that the brake thermal efficiency of the biodiesel blend was about 3.4% lower under constant speed running conditions than constant torque operating conditions. Similarly, about 6.5% lower exhaust gas temperatures under constant speed running conditions with lower peak pressure were found than under constant torque testing conditions. On the subject of emission, it is seen that the testing conditions also have an influence on exhaust emission. For instance, under constant speed running conditions, the engine produces about 19.5% lower NO and 19% higher HC than under constant torque running conditions. A similar influence was also found in the pressure and heat release rate. However, there is a clear variation found in the results under different operating conditions. Therefore, it is necessary to test the fuel under various operating conditions, such as constant torque, constant speed, variable injection timing, for the optimal use of biodiesel
A comparative study of C4 and C5 alcohol treated diesel–biodiesel blends in terms of diesel engine performance and exhaust emission
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