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Biofuels play an essential role in the global energy landscape, providing a renewable alternative for transportation fuels. In 2010, global biofuel production reached 105 billion liters, meeting 2.7% of the world's fuel demands, primarily through ethanol and biodiesel. The paper discusses the history of biofuel, focusing on vegetable oil-based fuels and their potential growth in significance as alternatives to fossil fuels.
Biocatalysis and …, 2008
Journal of the Brazilian Chemical Society, 2005
A importância da produção de biodiesel, nos últimos cinco anos, é apresentada a partir de artigos científicos publicados e patentes depositadas. Foi realizada uma análise crítica sobre as fontes oleaginosas mais utilizadas como matéria-prima para produção de biodiesel, os catalisadores e os métodos de acompanhamento da reação de transesterificação. Também foram avaliados estudos comparativos entre emissões de diesel fossil e misturas, em várias proporções, com biodiesel. Finalmente, foram indicados desafios enfocando aspectos tecnológicos, agronômicos e de infraestrutura para produção de biodiesel. The importance of biodiesel production was analyzed based on scientific articles and patents. A critical analysis was presented on the most used oil sources, the catalysts and the methods to verify the transesterification yields. Also analyzed were the comparative studies on emissions from pure fossil diesel and mixtures with biodiesel in variable proportions. Finally some challenges and considerations focused on technological, agronomic and infrastructure aspects of biodiesel production were indicated.
The increasing industrialization and motorization of the world has led to a steep rise in the demand of fossil fuel and associated environmental issues. Fossil fuels are obtained from limited reserves and will run out eventually. Therefore renewable and environmental-friendly energy substitutes such as bio fuels as well as fuel efficiency improving methods are required.
International journal of engineering research and technology, 2019
In the recent past, intensive studies on internal combustion engines has emerged with a view to obtaining higher rate of production of fuels from alternative sources. The increase in alternative fuel investigations is caused by two main factors; a rapid decrease in world petroleum reserves and important environmental concerns originating from exhaust emissions. Fast depletion of the viable alternative fuels. Diesel fuel is largely consumed by the transportation sector. Thermodynamic tests based on the engine performance evaluations have established the feasibility of using vegetable oils. It has been found that vegetable oils hold special promise in this regard, because they can be produced from the plants grown in rural areas. Vegetable oils from crops such as soya bean, peanut, sunflower, rape, palm, coconut, karanja, neem, cotton, mustard, jatropha, linseed and caster have been evaluated in many parts of the world in comparison with other non-edible oils. To solve energy and envi...
Bioresource Technology, 2001
Methyl, ethyl, 2-propyl and butyl esters were prepared from canola and linseed oils through transesteri®cation using KOH and/ or sodium alkoxides as catalysts. In addition, methyl and ethyl esters were prepared from rapeseed and sun¯ower oils using the same catalysts. Chemical composition of the esters was determined by HPLC for the class of lipids and by GC for fatty acid compositions. The bio-diesel esters were characterized for their physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. Methyl and ethyl esters prepared from a particular vegetable oil had similar viscosities, cloud points and pour points, whereas methyl, ethyl, 2-propyl and butyl esters derived from a particular vegetable oil had similar gross heating values. However, their densities, which were 2±7% higher than those of diesel fuels, statistically decreased in the order of methyl $ 2-propyl > ethyl > butyl esters. Butyl esters showed reduced cloud points ()6°C to )10°C) and pour points ()13°C to )16°C) similar to those of summer diesel fuel having cloud and pour points of )8°C and )15°C, respectively. The viscosities of bio-diesels (3:3±7:6 Â 10 À4 Pa s at 40°C) were much less than those of pure oils (22:4±45:1 Â 10 À4 Pa s at 40°C) and were twice those of summer and winter diesel fuels (3.50 and 1:72 Â 10 À4 Pa s at 40°C), and their gross heat contents of approximately 40 MJ/kg were 11% less than those of diesel fuels ($45 MJ/kg). For dierent esters from the same vegetable oil, methyl esters were the most volatile, and the volatility decreased as the alkyl group grew bulkier. However, the bio-diesels were considerably less volatile than the conventional diesel fuels. Ó
The key purpose of the study is to find out the impact of internet banking to retain customers in the context of Mutual Trust Bank LTD, Bashundhara branch, Dhaka. There are some key factors that have an important impact on customer retention in the internet banking. The main findings of the study will indicate that the factors, which are Service Quality, Responsiveness, Security and Privacy, Assurance, and Reliability, have impacts on customer retention in terms of Internet Banking of MTBL, Bashundhara branch.
Хайрединова Э. А. Наперстки XIII–XIV вв. из города на плато Эски-Кермен // Античная древность и средние века. 2023. Т. 51. С. 250–266. https://doi. org/10.15826/adsv.2023.51.015, 2023
This article publishes the thimbles of bone, horn, and bronze alloys excavated on the plateau of Eski-Kermen in the quarters that perished in a fire from the late thirteenth century, and in the graves of the fourteenth-century cemetery located in front of the main basilica. According to the material and form, there are reasons to divide the finds into five types. Judging by the finds from the quarters, the thirteenth-century residents of the town on the Eski-Kermen plateau used bone or horn thimbles of type 1, as well as bronze plate or cast thimbles of types 2–1, 2–2 and 3. Bone thimbles were probably produced by local artisans, and bronze products were most likely imported from Cherson, which established close economic ties with the inhabitants of the town on the Eski-Kermen plateau. In the fourteenth century, there appeared brass-stamped closed thimbles of small diameter, with a hemispherical upper part, of types 4 and 5, which could be worn only on the finger-tip. Similar thimbles were found in the prince’s palace in Mangup and in the castle of Chembalo. Perhaps the residents of the “cave towns” obtained these goods from the trade with the Genoese. The presence of thimbles in dwelling houses makes a clear illustration of the written accounts that needlework was among the main occupations of Byzantine women. It is known that the landladies, along with textile manufacture, often had to sew and repair clothes. In the fourteenth century, the residents of the town on the Eski-Kermen plateau often buried dead women accompanied with thimbles used during their lifetime. Apparently, the thimble was not only necessary in a woman’s daily life, but also had a certain symbolic meaning.
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