Search

Natural antioxidants are available in various biomass substances which can be used for improving human health and fuel oxidation stability. This research is aimed at using a natural antioxidant powder obtained from Albizia lebbeck leaves powder to improve the oxidation stability of an optimal Jatropha methyl ester (JME)-diesel blend. Initially, Albizia lebbeck leaves are characterized by x-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy for their oxidant behavior. The optimal JME diesel blend (JME20) has a mixture of 20% JME and 80% diesel. The antioxidant at different concentrations, viz., 500, 1000, 1500, and 2000 ppm, is doped in JME20, and the blends are designated as AL1, AL2, AL3, and AL4, respectively. The test engine is converted to run on the low heat rejection (LHR) mode by coating the piston with a mixture of two different ceramic materials, i.e., yttria-stabilized zirconia and cerium oxide (CeO2), with a thickness of 0.3 mm of the topcoat and 0.15 mm of the bond coat of material NiAl. The emissions, performance, and combustion of the test engine run on antioxidant-doped JME20 fuels in conventional engine operation and LHR mode are evaluated, analyzed, and presented in this paper. Results indicate that, among the four antioxidant-doped JME20 fuels, JME20AL4 gives better performance and lower exhaust emissions. The engine's cylinder pressure and heat release rate are decreased by about 4.7% and 6.4%, respectively, at full load, for JME20 AL4. The delay period and combustion duration of the fuel are improved by about 26.8% and 10.8%, respectively, at maximum load. The NO, HC, and CO emissions are reduced by about 17.3%, 19.3%, and 44.2%, respectively, for JME20 AL4, at maximum load. [ABSTRACT FROM AUTHOR]

In this paper, a series of BiOBr photocatalysts have been synthesized by solventhermal method using different solvents (water, ethanol, isobutanol, ethylene glycol, and glycerol), and were characterized by X-ray diffraction, scanning electron microscope, UV-visible diffuse reflectance spectra, and X-ray photoelectron spectroscopy. It is found that the solvent plays a key role to tune the morphology, crystal growth, and surface nature of BiOBr. The photodegradation rate of reactive brilliant blue (KN-R) over BiOBr photocatalysts prepared by water, ethanol, isobutanol, ethylene glycol, and glycerol as solvents are 52.5%, 65.0%, 54.6%, 66.1%, and 90.9%, respectively, under sunlight irradiation for 120 min. The flower-like hierarchical BiOBr prepared by glycerol as solvent exhibited better photocatalytic activity for the degradation of reactive brilliant blue (KN-R) under sunlight irradiation. The excellent photocatalytic activity of BiOBr prepared by glycerol as solvent can be attributed to its high exposed active face, little crystal size, and abundant oxygen vacancies. Furthermore, recycled photodegradation experiments indicated the catalyst did not exhibit any significant loss of photocatalytic activity after five recycles, which confirmed the photocatalyst is essentially stable. [ABSTRACT FROM AUTHOR]

Dye sensitized solar cells were fabricated by sensitizing with Begonia dye extracted from a new variant of Begonia plant which is found in the Eastern Himalayas. The quality of TiO2 coated substrate was analyzed using Scanning Electron Microscope, X-ray diffraction, and Transmission Electron Microscopy. The extracted dye and the dye-sensitized TiO2 coated substrates were subjected to UV-Vis spectrophotometer, fluorescence and Fourier transform infrared spectroscopic studies. The presence of anthocyanin in Begonia dye has been confirmed from above studies. Thermal studies of the dye extract reveal that it is stable till 150 °C. The fabricated cells have efficiency in the range 1.73-1.86%, which is the highest known efficiency in anthocyanin based natural dye sensitized solar cell. [ABSTRACT FROM AUTHOR]

Wind turbine gearbox is one of the most expensive and critical components of the wind turbine generator system. Due to the extreme operating conditions encountered in the gearbox, there is little room for compromises, especially with the performance of the lubrication system. Gearbox lubricating fluid is one of the most important elements of the system-it is analogous to the blood in human body, performing key functions, which in the case of gearbox are maintaining proper lubricity and film thickness between the moving surfaces, heat absorption and its dissipation, suspension and transportation of the particulate debris, prevention of abrasion and corrosion, etc., in the lubrication system. Therefore, the optimum cleanliness level and health of the lubricating fluid is essential for satisfactory performance and service life of the wind turbine gearbox. The paper discusses the cleanliness control and management of the gearbox lubrication system. Examples of filtration related issues experienced in the field are also discussed. [ABSTRACT FROM AUTHOR]