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Renewable and sustainable fuel usage in diesel engines ensures energy security and overseas exchange savings besides conveying both socioeconomic and environmental concerns. This research presents experimental work that has been done on single-cylinder, 4-stroke, diesel engine of direct injection run in DF mode using PG derived from sugar cane bagasse renewable and sustainable fuels. A 45° gas venture is designed and developed to provide a stoichiometric mixture of gas and air entry into the intake manifold of the DF engine during suction stroke. A compressed mixture of air and gas is ignited by injecting diesel into the engine cylinder at 205 bar pressure and at different timings of injection. The effect of timing of injection on the DF engine performance is studied by varying it from 23 to 31obtdc in steps of 4obtdc. Experimental investigation showed that 27oBTC resulted in improved BTE with reduced emissions of hydrocarbon, smoke, and CO while NOx, peak pressure increased. It is noticed that the operation of producer gas lowers the power derating by 20% and the DF engine could run up to 80% load with increased nitric oxide (NOx) emissions. The developed DF engine worked satisfactorily with acceptable performance and emission norms and assisted in partially substituting the fossil diesel fuel with a substitution of 60-70% by the PG operation. [ABSTRACT FROM AUTHOR]

Improving the cooling performance of electronic devices and engines, unlike is an important area that is being investigated by several investigators. Poor performance of conventional cooling methods has necessitated enhancing heat transfer by using different fins with different configurations. Further various thin film coatings on fins using different nano-particles of silver, copper and carbon-based materials like Graphene, Multi Walled Carbon Nanotubes (MWCNTs) and their benefits in enhancing heat transfer have been reported in the literature. This work involves highlights on heat transfer characteristics of heat sinks having different shapes such as copper concave, aluminium congruent and copper flat plate. These differently shaped heat sinks were subsequently coated with graphene nanoparticles and their effect on heat transfer characteristics is studied. The outcomes obtained from the experimental forced convection are used to compare the heat transfer characteristics for different heat sinks with and without nano-coating. The experiment is conducted for varied voltage inputs and the heat dissipation is compared. Different parameters like surface temperature, Nusselt number, Reynolds number, and effectiveness are compared for different heat sinks with and without nano-coating. Experimental analysis showed that for a constant voltage input of 100V, copper concave, aluminium congruent and copper flat plate-shaped heat sinks with graphene coating showed higher heat transfer coefficients which more by 45.35%, 40.64%, and 21.43% when compared to those without the coating. Also, the Nusselt number increased by 9.9%, 13.9% and 40% accompanying a decrease in thermal resistance by 40%, 30.9% and 30.36% with respect to those without the coating. The copper concave-shaped heat sink, with graphene nano-coating exhibited a higher heat transfer coefficient, higher Nusselt number and decreased thermal resistance compared to that without coating and hence can be used in electronic elements for greater heat dissipation. [ABSTRACT FROM AUTHOR]

Various nanofluids (NFs) have been prepared using nanoparticles (NPs) for dual fuel engine application in this present work. In the initial segment of the work, the NF's are prepared using aluminum oxide nanoparticles (Al2O3). Further, nanoparticles were blended with diary scum oil methyl ester (DiSOME) in the mass fraction of 10–30 ppm in steps of 10, with the assistance of a mechanically operated conventional homogenizer and an ultrasonicator. In the next segment of the work, Al2O3 NP's effect on the characteristics of ignition and engine outgas levels of a single cylinder four strokes direct injection diesel engine functioning on dual fuel mode using DiSOME and producer gas (PG) has been investigated. Engine testing showed that experiments with Al2O3 based NF and PG operation resulted in 11.5% amplified brake thermal efficiency, 23.2% reduction in smoke, 18.2–21.4% reduction in hydrocarbon (HC) and carbon monoxide (CO) emissions, while more significant nitric oxide (NOx) levels by 32.6% were achieved than the same fuel combination excluded NP's at 80% load. [ABSTRACT FROM AUTHOR]

The exhaust gas recirculation (EGR) consists of reverting a certain portion of the exhaust gases into the engine cylinder. EGR dilutes the air-fuel mixture in the cylinder reducing the combustion chamber temperature and NOx with a penalty in the value of brake thermal efficiency. EGR as a NOx reduction technique for modified POME fuelled diesel engines has been investigated in the present work. The EGR rate is varied from 0% to 20% for the present study. An EGR rate of 10% has been optimized which results in the decrease in brake thermal efficiency by 3.4%, peak pressure (PP) by 5.6%, heat release rate (HRR) by 10.8% and oxides of nitrogen (NOx) by 1.2% as compared to that without EGR. An increase in emissions such as carbon monoxide by 5%, unburnt hydrocarbons by 10.5% and smoke by 12.8% are observed. [ABSTRACT FROM AUTHOR]

The work presented is an effort to realize the changes occurring for convective coefficients of heat transfer in STHX fitted with inclined baffles. Effort has been undertaken using Fluent, a commercially available CFD code on a CAD model of small STHX with inclined baffles with cold liquid flowing into the tubes and hot liquid flowing in the shell. Four sets of CFD analysis have been carried out. The hot liquid flow rate through shell compartments varied from 0.2 kg/sec to 0.8 kg/sec in steps of 0.2 kg/sec, while keeping the cold liquid flow condition in tube at 0.4 kg/sec constant. Heat transfer rates, compartment temperatures, and overall heat transfer coefficients, for cold liquid and hot liquid, were studied. The results given by the software using CFD approach were appreciable and comparatively in agreement with the results available by the experimental work, which was undertaken for the same set of inlet pressure conditions, liquid flow rates, and inlet temperatures of liquid for both hot and cold liquids. The experimental output results were also used to validate the results given by the CFD software. The results from the CFD analysis were further used to conclude the effect of baffle inclination on heat duty. The process thus followed also helped realize the effects of baffle inclination on convective heat transfer coefficient of the liquid flow through the shell in an inclined baffle shell and tube heat exchanger. The temperature plots for both cold and hot liquid were also generated for understanding the compartmental temperature distributions inclusive of the inlet and outlet compartments. The heat duty for a heat exchanger has been found to increase with the increase in baffle inclinations from zero degree to 20 degrees. Likewise, the convective heat transfer coefficients have also been found to increase with the increase in baffle inclinations. [ABSTRACT FROM AUTHOR]

Today, oral disorders are the most prominent and common issues in the world. Investigations reveal oral disorders comprising of gum disease, tooth decay, mouth sores, tooth erosion, tooth sensitivity, toothaches, and dental emergencies. Further, in-depth study identifies improper bonding between denture base and denture teeth ending up with costly repair along with mouth sores. This effect is observed from middle age (35 years) to old age (< 80 years) people in the world. Approximately one-third of the population is suffering because of untreated caries of natural teeth (31.2 %). The optimal composition of PMMA as denture base and denture teeth in clinical trials with observation and experimental methodology is yet to be unleashed. An alternative material for denture base or denture teeth is still an unanswered question. Selection of appropriate reinforcement material encompassing the guidelines for liquid/powder ratio, avoids processes terrible for bond strength, the wax free model. The current work focuses on investigation of mechanical properties with/without the reinforcement of a new biomaterial known as limpet teeth (LT). LT is abundantly available in the seashore or intertidal regions. Application of LT in dentistry or as a denture base material is unperceived. A comparative analysis of coupons with/without the reinforcement (in the form of a short/continuous fiber) of LT in PMMA is carried out. The simulation work correlates with experimental work exploring the possibilities of a new material in the field of dentistry. The observed results for mechanical properties such as flexural strength (106 %), microhardness (116 %) and impact strength (125 %) are better in comparison to base PMMA material. [ABSTRACT FROM AUTHOR]