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Out of various strategies to extenuate the diesel engine emissions, use of water-blended diesel fuel in emulsified form is found to be a prominent option. The studies carried out by various researchers give quite inconsistent results for optimum water concentration, surfactant concentration, and HLB value. An effort has been made in this paper to analyze this inconsistency of water concentration and surfactant for engine emissions and performance along with the effect of compression ratio. The work has been carried out on a non-road, constant rpm, VCR (variable compression ratio) diesel engine. Different emulsions of 5%, 10%, 15%, and 20% water-in-diesel with 3% emulsifier concentration were tested on the diesel-optimized engine at CR 21. The results showed that emulsion of 15% water-in-diesel is optimal on the basis of emissions and performance. Further, the selected 15% emulsion is tested with 4% emulsifier concentration. It improved the stability of emulsion and performance of the engine with slight adverse effects on the NOx emissions. Then, emulsion with 4% surfactant and 15% water is tested to determine optimum compression ratio for emulsified fuels. CR 20 is found in optimum. Remarkably 9.28% improvement in BTE is observed reaching up to 23.89% as compared to 21.86% with bare diesel. 25.1% reduction in NOx and more than 50% reduction in smoke is observed. Overall, it is concluded that the water-blended diesel emulsion could serve as a fuel-efficient cleaner combustion technology and needs to be standardized. Abbreviations HLB: Hydrophile–Lipophile Balance; Cv: Calorific Value; W/D: Water in Diesel; PM: Particulate matter; RPM: Rotation per minute; HC: Hydrocarbon; CR: Compression Ratio; EGT: Exhaust Gas Temperature; BTE: Brake Thermal Efficiency; NOx: Oxides of Nitrogen; BSFC: Brake specific fuel consumption [ABSTRACT FROM AUTHOR]

Abstract:Photoacoustic spectrophotometer (PAS) has emerged as the most promising technology with its promise to resolve unmet issues in various domains. The advantages of PAS are nonvulnerability of the sample, trace quantity sample analysis, and short response time. Though it showed distinguished features close to its emergence, it is bereft of its importance in the present scenario. Certainly, there exists a transparent gap in understanding the current situation in forensic crime scene management and the application of PAS within the same discipline. This article aims to consolidate all this information to fill an existing knowledge gap and tries to establish trajectory of research done up to now. This article will also pinpoint the reasons behind why this advanced technique could not accomplish its respectable feat inside the market and restraint of optical business toward inventing and commercializing this merchandise. [ABSTRACT FROM PUBLISHER]

Various agricultural wastes such as peels of pea (Pisum sativum) pod, tea (Camellia sinensis), and ginger (Zingiber officinale) and banana (Musa lacatan) waste were used to adsorb Cr(VI) from the aqueous solutions. A comparative adsorption efficiency study for all these adsorbents was done in laboratory for various pH, adsorbent doses, initial chromium concentrations, contact time, adsorbent sizes, temperature, and mixing speeds up to the optimization. The equilibrium sorption data were fitted into Langmuir, Freundlich, and Temkin isotherms and also the various thermodynamic parameters were determined. The value of R2 was determined for Freundlich, Langmuir, and Temkin as 0.964, 0.963, and 0.858 (pea pod peels waste (PPP)), 0.969, 0.986, and 0.841(tea & ginger waste (T&G)), 0.985, 0.982, and 0.886 (banana peel waste (BW)). The maximum monolayer coverage (Q0) from Langmuir isotherm model for pea pod, tea & ginger and banana peels waste were found to be 4.33 mg/g, 7.29 mg/g, and 10 mg/g, respectively, with separation factors (RL) 0.0331, 0.0343, and 0.0756 which are well within favorable sorption. From Freundlich isotherm model, the sorption intensity (n) for the same adsorbents was also less than unity showing normal sorption. The heat of sorption (B) was also determined from Temkin isotherm model as 0.215, 0.271, and 0.271, respectively, vividly proving a favorable physical sorption. The Gibbs free energy was found maximum for BW as 6.0679 joule/ mole. Out of the above said combination, BW was found the best low-cost adsorbent with high potential for the removal of hexavalent chromium from aqueous solutions. [ABSTRACT FROM AUTHOR]

Along with industrialization and transportation, the higher living standard is also the main reason for the increase in energy demand. This increasing energy demand motivates researchers to find new alternative fuels that are eco-friendly and sustainable. In this concern, to analyze the performance, emissions, and combustion characteristics of an SI engine fueled by petrol-acetylene under DF mode is the main purpose of this study. For this purpose, a VCR spark ignition engine was used and operated at the engine maximum speed (1800 rpm). The experimental study was carried out at different acetylene gas flow rates and spark timing.In this study, the acetylene gas flow rate was first optimized on a performance basis. Furthermore, the engine was run at an optimized acetylene gas flow rate (100 LPH) to find out the optimum value of spark timing. In further experimentation, it is also found that the BThE to be maximum and emissions were significantly low or comparable at spark timing 20º CA bTDC (at 100 LPH) as compared to other spark timing and baseline case at all loads. The effects of NOx and smoke are not considerable. Hence, it is not covered in this study. The heat release rate and peak cylinder pressure are found to increase with the advancement of spark timing. But knocking was observed at higher spark advance. [ABSTRACT FROM AUTHOR]