119 research outputs found
Application of blend fuels in a diesel engine
AbstractExperimental study has been carried out to analyze engine performance and emissions characteristics for diesel ngine using different blend fuels without any engine modifications. A total of four fuel samples, such as DF (100% iesel fuel), JB5 (5% jatropha biodiesel and 95% DF), JB10 (10% JB and 90% DF) and J5W5 (5% JB, 5% waste ooking oil and 90% DF) respectively were used in this study. Engine performance test was carried out at 100% load eeping throttle 100% wide open with variable speeds of 1500 to 2400rpm at an interval of 100rpm. Whereas, mission tests were carried out at 2300rpm at 100% and 80% throttle position. As results of investigations, the erage torque reduction compared to DF for JB5, JB10 and J5W5 was found as 0.63%, 1.63% and 1.44% and verage power reduction was found as 0.67%, 1.66% and 1.54% respectively. Average increase in bsfc compared to F was observed as 0.54%, 1.0% JB10 and 1.14% for JB5, JB10 and J5W5 respectively. In case of engine exhaust as emissions, compared to DF average reduction in HC for JB5, JB10 and J5W5 at 2300rpm and 100% throttle osition found as 8.96%, 11.25% and 12.50%, whereas, at 2300 and 80% throttle position, reduction was as 16.28%, 0.23% and 31.98% respectively. Average reduction in CO at 2300rpm and 100% throttle position for JB5, JB10 and 5W5 was found as 17.26%, 25.92% and 26.87%, whereas, at 80% throttle position, reduction was observed as 0.70%, 33.24% and 35.57%. Similarly, the reduction in CO2 compared to DF for JB5, JB10 and J5W5 at 2300rpm nd 100% throttle position was as 12.10%, 20.51% and 24.91%, whereas, at 80% throttle position, reductions was bserved as 5.98%, 10.38% and 18.49% respectively. However, some NOx emissions were increased for all blend els compared to DF. In case of noise emission, sound level for all blend fuels was reduced compared to DF. It can e concluded that JB5, JB10 and J5W5 can be used in diesel engines without any engine modifications However, 5B5 produced some better results when compared to JB10
Effect of stabilizer on optical band gap of ZnO and their performance in dye-sensitized solar cells
ABSTRACT. In dye-sensitized solar cells, transparent metal oxide working electrodes play a vital role in defining the power conversion efficiency. It was found that the size of nanoparticles influences the electrical, optical properties of these electrodes. Herein, we describe the synthesis of ZnO with zinc acetate dihydrate and different stabilizers (diethylamine and triethylamine) by using a modified solvothermal process. The obtained materials were characterized by XRD, SEM, EDX, TEM, HRTEM, UV-visible, FTIR, and Raman methods. The crystallite sizes for ZnO-1 and ZnO-2 samples were indexed as 39.0 and 40.5 nm for the highest peak intensity with diethylamine and triethylamine stabilizer, respectively. We examine the effect of stabilizers on the morphology, optical band gap, and photovoltaic performance of the prepared ZnO. We found that ZnO prepared using diethylamine stabilizer exhibiting significant efficiency of 1.45%, open-circuit voltage 0.454 V, short-circuit current density 2.128 mA/cm2, and 0.66 fill factor were achieved under 44 mW/cm2 illumination powers with dye-3.
KEY WORDS: Dye-sensitized solar cells, ZnO, Band gap, Photovoltaic performance
Bull. Chem. Soc. Ethiop. 2022, 36(1), 209-222.
DOI: https://dx.doi.org/10.4314/bcse.v36i1.17  
Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in Bangladesh During 2011
postprintA case control study was conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20/43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were done. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective.
Key words:
Avian influenza; case-control study; logistic regression; risk factors, observational studies
Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in Bangladesh During 2011
A case control study was conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20/43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were done. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective. Key words: Avian influenza; case-control study; logistic regression; risk factors, observational studies
Sustainable production of furan-based oxygenated fuel additives from pentose-rich biomass residues
The emission of carbon monoxide, greenhouse gases (e.g., carbon dioxides), hydrocarbon, and particulate matter can be reduced by applying oxygenated additives as a blend to combustible hydrocarbon fuels. However, conventional oxygenates, such as dimethyl ether and methyl t-butyl ether, are sourced from non-renewable feedstocks. This study presents a critical review on the catalytic synthesis of furanic compounds, as an alternative to the conventional oxygenated fuels, from highly abundant lignocellulosic biomass (LCB). This study aims to evaluate the potential of production of furan-based oxygenated fuel additives (e.g., 2-methyl furan, 2-methyl tetrahydrofuran, alkyl levulinates, ethylfurfuryl ether, ethyl tetrahydrofurfuryl ether, tetrahydrofurans) from LCB via the C5-sugars pathway (through furfural); the fuel properties and the performance of furanic fuels in SI or CI engine. The review showed that selecting solvents and catalysts is critical in improving the yield of furanic compounds and reducing the generation of intermediates. The biphasic system for the one-pot conversion of LCB (dehydration and hydrogenation) into furans could facilitate the final product separation and improve final product yield. The combination of Brønsted/Lewis acid catalysts or heterogenous catalysts is promising for effectively converting LCB (alcoholysis) into alkyl levulinates. The use of biomass-based furan fuel additives could potentially have a substantial positive impact on the life cycle analysis of furan/fuel blends due to the availability of lignocellulosic biomass-based feedstocks and improving the sustainability of fuel additives synthesis sourced from LCB wast
Engine performance and emissions analysis using “Envo Diesel” and coconut biodiesel blended fuel as alternative fuels
The Environmental concerns and regulations to reduce green house gas emission and fluctuation of fossil fuel price have stimulated research on alternative fuels. Moreover, use of unproductive land to produce vegetable oil which is a potential biodiesel source has opened up a way to reduce oil
bill. Biodiesel does not need major modification in engine, even though it causes some engine problems in long term use. This paper presents experimental results that evaluates the
performance and exhaust emissions of a diesel engine
operated on “Envo Diesel” which consists of 5% palm diesel
and 95% ordinary diesel fuel (also termed as P5) and C5 (5%
coconut biodiesel and 95% ordinary diesel fuel. Experimental
results showed that P5 and C5 reduced brake power compared
to diesel fuel by 1.2% and 0.7% respectively. Emissions such as HC, smoke, CO and NOx concentration were lesser for P5 and C5. The results of this investigation will be used to partial replacement of diesel fuel using low percentage of methyl ester (maximum 5%) obtained from waste vegetable oils
Effect of synthetic antioxidants on storage stability of calophyllum inophyllum biodiesel
Biofuels especially biodiesel derived from renewable sources are becoming important increasingly due to environmental and energy concerns. Biodiesels are composed of long chain unsaturated fatty acid esters that are prone to oxidation. Non-edible high acid value calophyllum inophyllum oil based biodiesel (ClME) was produced by two stage esterification and one stage transesterification process. The oxidation stability of biodiesel treated with three prominent antioxidants namely Pyrogallol (PY), Propyl gallate (PG), and Tertbutylhydroxyquinone (TBHQ) was evaluated. The induction period ofbiodiesel with or without antioxidant was measured according to EN141l2 standard using a Rancimat instrument. Antioxidants were added at 500 ppm, which in general improved the induction period. Samples were kept for 70 days and different properties that change during storage namely induction period, density and kinematic viscosity were monitored. For all samples oxidation stability decreased and kinematic viscosity increased due to formation of oxidation products. PY showed the best effect in retaining oxidation stability of calophyllum inophyllum biodiesel
Significance of journal paper publication and guideline in postgraduate study
In a recent change of policy reviewed by University of Malaya (UM) postgraduate students are required to
publish journal paper before they are awarded their degrees. In a new curriculum effective from 18 December
2008, postgraduate students by research mode are required to publish minimum of one Institutes of Scientific
Information (ISI) journal paper for Master degree and two ISI journal papers for Doctor of Philosophy (Ph.D.)
degree. Public universities are fervent for paper publication as it has an impact on university world ranking so
the requirement is designed to boost the number of journal paper publication of the university and a good
opportunity of the student’s future career. The paper publication increases critical thinking, data analysis skill
of the student and many other obvious advantages. University of Malaya has global recognition with state of the
art research facility and provides student with fellowship and research assistantship for financial aid so that
student can accomplish the desired goal. Students can apply for short term Research and Development (R&D)
grant named as postgraduate research fund for the expenditure of their research purposes. This paper discusses
the significance of publishing journal paper by postgraduate student to fulfill University requirement and their
future career development. The mutual benefit between student and university for publishing journal was also
highlighted
Performance of a diesel engine fueled with a preheated blend of soybean oil and petrodiesel
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