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Composites made of aluminium and other materials are now essential materials for a variety of engineering tasks, including those in the automotive industry. The present work reports on the machinability studies of Al 6061 hybrid metal matrix composites (HMMC). For the investigation, Al6061 alloy is reinforced with Boron carbide and Graphene nanoparticles (GNp) and the hybrid composite was prepared by stir casting under suitable conditions. The Electrical discharge machining (EDM), advanced machining process, was chosen to machine HMMC as it is difficult to machine by conventional machining. EDM machinablity studies were done on stir casted Al-B4C-GNP composites. The optimization of EDM process parameters were carried out using L27 orthogonal approach with input parameters such as pulse on time, pulse off time and peak current for the response of material removal rate (MRR) and surface roughness.

Cu2ZnSnS4 (CZTS) is a promising quaternary semiconducting absorber layer in thin film heterojunction solar cells. All the elements of this compound semiconductor were abundant, inexpensive, and non-toxic, hence CZTS is an alternative emerging optoelectronic material for Cu(In,Ga)Se2 and CdTe solar cells. Using the traditional spray approach, these films were effectively grown at an ideal substrate temperature of 643 K. The deposited films are found to be a kesterite structure using X-ray diffraction studies. The lattice parameters are calculated from the XRD spectrum and are found to be a = b = 5.44 Å and c = 10.86 Å. The energy band gap and optical absorption coefficient are found to be 1.50 eV and above 104 cm-1 respectively. The material exhibits p-type conductivity. After the chemical spray pyrolysis is completed, the deposited films remain on the hot plate, thus improving the films' crystallinity. A Cu2ZnSnS4 solar cell is fabricated using entirely chemical synthesis methods.

The current study focus on the effect of thermal barrier coated (TBC) piston on diesel engine and also the emission characteristics. The test engine piston was coated with a Ni-Cr-Al-Y bond coat of 50 μm thick and a top coat of 250 μm thick with a mixture of 93% of ZrO2, 3 % of Y2O3, 2 % of Gd2O3 and 2% Nd2O3 which is coated onto the target surface by following the plasma spray technique. The experimentation will be conducted in a 4-stroke 1-cylinder diesel engine using diesel, Mahua (MB 100) and Jatropha (JB 100) fuels with and without coating. As a result of this investigation, it was found that a coated engine’s brake thermal efficiency (BTE) had increased by 2.8% when compared to the baseline engine and the brake specific fuel consumption (BSFC) has been reduced by 3.2 % with a coated piston when compared to the baseline piston when JB 100 was used as a fuel.

CuSbS2 is a promising compound semiconductor for the thin film heterojunction solar cell absorber layer. The chemical spray pyrolysis technique is adopted to fabricate CuSbS2 thin film solar cells. The aqueous solution is sprayed over the soda-lime glass substrates at a constant spray rate of 10 ml/min. The films are obtained at the optimum substrate temperature of 260 °C. The thin films' of XRD spectra reveal the polycrystalline nature of the chalcostibite structure of CuSbS2, with lattice parameters of a = 0.600 nm, b = 0.380 nm, and c = 1.445 nm respectively. Micro-Raman spectra also confirm the CuSbS2 crystal phase. The optical band gap of these films is found to be 1.44 eV, which is close to the optimum band gap for maximal conversion efficiency. The optical absorption coefficient of these films is ≥ 104 cm-1. These films are found to be p-type. Finally, work on fabricating a conventional thin film heterojunction solar cell is undertaken.

The current research was aimed at determining the most effective way to use alternative renewable feedstock to power a diesel engine. Mimusops elengi, a new and novel biofuel was recognized for this current study, which is widely available in the south of India. The investigation was conducted on B20 volume basis (20% Mimusops elengi methyl ester blended with 80% diesel). Furthermore, it was recognized that when the performance characteristics were traded off, the emission magnitude has slightly higher. To address the diesel engine pollution, an oxygenated nano additive like titanium oxide was dissipated only with the fuel blend at distinct mass fractions of 25 parts per million (ppm) with differing injection pressures of 180 bar, 200 bar, 220 bar, and 240 bar. The tests were created using a statistical programme known as design of experiments, which is purely based on Taguchi and response surface methodology.

In the present work, Four-stroke DI diesel engine using Rape seed biodiesel was tested for performance and emissions characteristics. Compared to diesel, RSBD lowered the brake thermal efficiency by 5.7%, HC emissions by 28%, CO emissions by 23%, smoke emissions by 4%, and NOX emissions by 24%. To increase the thermal efficiency and to reduce the NOx emission using RSBD as fuel, the concept of thermal barrier coating on the piston was introduced along with 15% EGR. Due to the combined effort of oxygenated biodiesel and ceramic coating at the piston crown, the NOx emission increased significantly during the operation of the engine. Results show a 3.5% decrease in brake thermal efficiency, a 2.8% increase in HC emissions, a 4% increase in CO emissions, an additional 2% increase in smoke emissions, and a 6.2% increase in NOX emissions with a 15% EGR and TBC Piston over a standard diesel engine running on RSBD.

The engine parameters of a diesel engine (using coated and uncoated pistons) operating with alumina additive chlorella vulgaris biodiesel blends were evaluated experimentally. The properties of test fuel samples were investigated using ASTM standards, and the composition of C. Vulgaris biodiesel was also examined using an FTIR report. A diesel engine’s performance and pollution characteristics were studied using different fuel samples such as diesel, CBD20, CBD20ANP with coated and uncoated pistons. The experimental results showed that the coated engine had a higher BTE (1.8-3.2 percent) and a lower BSFC (1.2-3.8 percent) than the uncoated engine. It is also identified that, exhaust emissions like as CO, HC, and smoke opacity have also been moderately reduced with the coated engine, while NOx emissions were slightly increased.

Biodiesel is a non-toxic, biodegradable and renewable alternative fuel that can be used as a replacement for diesel in diesel engine. Liquefied Petroleum Gas (LPG) is considered to be one of the most promising alternative fuels. LPG can replace petrol and also it reduces NOx, soot and particulate matter. Therefore, it is more inexpensive and of ecological advantage to use gaseous fuel in diesel engines approved for the dual fuel concept. The fuel injection pressure is one of the important operating parameters which affect atomization of fuel and mixture formation and hence it determines the performance and emissions of a diesel engine. There will be a decrease in the particle diameter due to increase in the fuel injection pressure and it leads the diesel fuel spray to vaporize quickly. However, with decreasing fuel particles their inertia will also decrease and for this reason fuel can not penetrate deeply into the combustion chamber.