BIOREDUCTION OF SILVER NANOPARTICLES FROM AQUEOUS STEM EXTRACT OF CATHARANTHUS ROSEUS AND BACTERICIDAL EFFECTS.

Objective: Silver nanoparticles (AgNPs) were synthesized using the stem extract of the Catharanthus roseus (L.) plant using the green method. Theextract from the stem of C. roseus plant was obtained using standard dry powder extraction method. The colorless silver nitrate solution was changedinto brown color after the addition of stem extract indicates the formation of AgNPs. The chemical compounds present in the stem extract wereacting as a reducing agent for the synthesis of AgNPs. Methods: The AgNPs were analyzed with the help of UV-visible spectrophotometer for initialconfirmation. Fourier transform infra-red spectroscopy (FT-IR) confirmed the presence of various phytochemicals such as carbohydrate, phenoliccompounds, flavonoids, saponin. and alkaloids which were responsible for both reduction and stabilizing the action of the silver nanoparticles.Results: From the transmission electron microscopy analysis, it was confirmed that Ag-nanoparticles are in nanosize range between 40-50nm andare mono dispersed of particle distribution. Conclusion: From the zone of inhibition, it was confirmed that the synthesized Ag NP from the C. roseusstem was found to have a very high antimicrobial effect. From this study, it is clear that the AgNp can be used as a potential antimicrobial agent.Keywords: Catharanthus roseus, Silver nanoparticles, Anti-microbial activities

Synthesis of Persea Americana Bio-Oil and Its Spectroscopic Characterization Studies

The present investigation aims to evaluate the feasibility of using Persea americana (Avocado) biodiesel in compression ignition engines. Persea americana bio-oil was extracted through a soxhlet extraction process using n-hexane solvent after careful pre-processing of the feedstocks. Since the Free Fatty Acid content was 1.78% estimated through titration, single stage base-catalyzed transesterification technique was adopted using methanol and sodium hydroxide as catalysts in the molar ratio of 1:6. Gas Chromatography-Mass Spectrometry analysis revealed the presence of Oleic acid in major proportions. The Fourier transform Infra-Red analysis confirmed the presence of carbonyl group ester ions between 722.19 cm-1 and 1460 cm-1. The 13C NMR and 1H NMR studies supported the successful transformation of triglycerides into Fatty Acid Methyl Esters with distinct peaks at 3.369 ppm and 48.147 ppm, respectively

Application of zero-dimensional thermodynamic model for predicting combustion parameters of CI engine fuelled with biodiesel-diesel blends

Biodiesel from non-edible vegetable oil seems to be a promising alternate for petro-diesel in the present energy scenario. This study analyses the experimental and theoretical effects on the blends of Bee Wax biodiesel with straight diesel on combustion parameters. A zero-dimensional mathematical model is developed to analyse the rise in in-cylinder pressure along with Wiebie’s heat release correlations, ignition delay, gas dynamics model, heat transfer model and frictional model. The combustion parameters include in-cylinder pressure rise, net heat release and rate of pressure rise are investigated and found to be higher for straight diesel and deteriorated with the increase in blends of BWB. The theoretical simulation also supports the experimental data with constant injection timing, speed and compression ratio

COMBUSTION ANALYSIS OF ALGAL OIL METHYL ESTER IN A DIRECT INJECTION COMPRESSION IGNITION ENGINE

Algal oil methyl ester was derived from microalgae (Spirulina sp). The microalga was cultivated in BG 11 media composition in a photobioreactor. Upon harvesting, the biomass was filtered and dried. The algal oil was obtained by a two step solvent extraction method using hexane and ether solvent. Cyclohexane was added to biomass to expel the remaining algal oil. By this method 92% of algal oil is obtained. Transesterification process was carried out to produce AOME by adding sodium hydroxide and methanol. The AOME was blended with straight diesel in 5%, 10% and 15% blend ratio. Combustion parameters were analyzed on a Kirloskar single cylinder direct injection compression ignition engine. The cylinder pressure characteristics, the rate of pressure rise, heat release analysis, performance and emissions were studied for straight diesel and the blends of AOME’s. AOME 15% blend exhibits significant variation in cylinder pressure and rate of heat release

Effect of varying the Compression ratio and Injection timing on Performance and emission parameters in CI engine using Mahua Bio-diesel

695-701<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Biodiesel derived from non-edible oils have become the need of the hour in order to solve the problem of oil crisis. In the present work, B20 blend of Mahua biodiesel was tested in a single cylinder diesel engine.The engine variables like CR and IT were adjusted together where CR was varied from 16 to 18 with injection timing 20°, 23° and 25° bTDC in order to evaluate the performance and emission parameters. BTE increased slightly and BSEC shown a very slight reduction at higher loads with B20 blend at standard setting. Higher increase in BTE and reduction in BSEC was observed with the advanced injection timing at higher loads. Emissions of UBHC, CO and Smoke reduced with B20 blend and further reduced with advanced injection timing whereas NOx emissions increased with B20 blend at standard setting and advanced injection timing.</span

Influence of

The importance of diesel engines for human application is growing day by day. The engine operating parameters also play a key role in tuning the engine conforming to the better performance and emission standards. The effect of varying the compression ratios has more impact on the performance, emission and combustion parameters. In this study, single cylinder direct injection CI engine was tested on varying the compression ratios of 18, 17 and 16 at varying loads. The combustion and performance variation on reducing the compression ratios were investigated clearly. Reduction in brake thermal efficiency and increase in exhaust gas temperatures were observed when compression ratio was reduced from 18 to 16. The brake specific fuel consumption was increased on reducing the compression ratio. Reduction of peak cylinder pressure was observed on reduction of compression ratio and the ignition delay period increased on reducing the compression ratio. The peak heat release rate was closer to TDC on increasing compression ratios from 16 to 18. The rate of pressure rise was also investigated and showed maximum of 5.38 bar/°CA and minimum of 0.78 bar/°CA on above compression ratios. Cumulative heat release was also evaluated in this study showing higher heat energy for higher loads and compression ratios. The performance and combustion parameters on the useful compression ratio of 18 were also justified