It is well known fact that thermal efficiency of the two stroke engines on road usually ranges from nearly 35 % to 45 % and remaining energy is dissipated to the surrounding media. Therefore, it becomes the primary need to improve the engine performance. From the past decade and so and exhaustive research is carried by various researchers towards attaining higher level of the engine performance by doing certain modifications of the engine component family. Majority of researches focused on adding of coatings on pistons and by using the blends the performance characteristics are studied. The main aim of the present work is to develop a novel piston that reduces the percentage level of pollutants release to atmosphere and aid in improving the performance of the system. The work mainly focused on influence of novel piston and different blends in enhancing the engine performance and suppressing the level of emissions, thereby reducing the global working effects. The experiments are performed on single cylinder two stroke SI engine by using conventional piston, novel piston-1 (Bi metallic piston with copper piston crown), novel piston-2 (Bi metallic piston with Br piston) and different blends. It is noticed that the emission levels of pollutants got reduced by using novel piston-1and E20 blend and performance wise also novel piston-1 and M20 blend gave the best results in overcoming the burning issues in two stroke SI engines.

No abstract

Alginate microspheres for a highly water soluble antidiabetic drug Metformin hydrochloride was prepared by ionic gelation method and investigated for its various physicochemical and release properties. To prevent a rapid drug release from alginate microspheres in simulated gastro-intestinal media, alginate microspheres were blended with polymers, hydroxy propyl methylcellulose, methylcellulose, chitin and chitosan and evaluated as additive polymers for controlling the drug release. Results indicated that quantity of polymer; gelating agent and time of cross-linking affected the shape, size and release characteristics from the prepared dosage forms. Use of polymers to retard the release of drug was effective. Drug release from the microspheres followed swelling and erosion. The selected batches sustained the release of the drug for more than 8 h. and showed drug entrapment efficiency up to 85%. As the polymer concentration in the formulation increased, the drug release generally decreased. HPMC-blended microspheres swelled but withstood the disintegration, showing an ideal linear release profiles. The zero order release was shown by all the formulations except when chitosan was incorporated. In comparison with chitosan-blended microspheres, HPMC-blended and MC blended alginate microspheres can be easily made and used for controlled drug delivery systems due to convenient process and better controlled drug release.

No abstract

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.