Effect of intake air oxygen enrichment for improving engine performance and emissions control in diesel engine

Stringent emission regulations and health awareness about air pollution have led researchers to find alternative means of minimising emissions in diesel engines. In this article, the influence of oxygen enrichment is discussed to determine the effect on diesel engine performance, emission characteristics and combustion characteristics. Normal diesel and oxygen-enriched diesel are used in this experiment. The increase in oxygen concentration led to complete combustion, producing higher thermal efficiency and low harmful emissions. From the results, it is noted that oxygen-enriched diesel fuel showed reduction of CO, HC and smoke emissions, while NOx emission increased.

Abbreviations/Nomenclature DI: direct injection; NOx: oxides of nitrogen; O₂: oxygen; HC: hydrocarbon; PM: particulate matters; CO: carbon monoxide; CO₂: carbon dioxide     

Design and analysis of reflectivity for Mylar-coated solar dish

Energy is the key driver of the economy but energy crisis is a problem for the present-day source of energy. The concentrated solar power systems make use of different reflector configurations to convert the solar energy into high-temperature heat energy. Parabolic dish system is considered as the best suitable system for achieving high temperature and so it is opted for the study. Here, a solar dish is designed with an open diameter of 1.8?m (which is 2.5?m² in area), and reflective film is being used to reflect the solar irradiance and concentrated it in the focal point. A receiver of 1?mm thickness and 10?cm diameter is used at the receiver end to measure the temperature of the focal point. The setup has made to attain a maximum temperature of 940°C and average temperature of 850°C in the focal point at clear sky in a sunny day.     

Optimisation of process parameters for electroless nickel plating on SS316L for refrigeration systems

Nowadays, refrigeration systems are important for industrial and domestic applications. The coefficient of performance of a vapour compression refrigeration system can be improved if a reduction in the work of compression can be achieved by a suitable technique for a specified heat removal rate. The present study investigates the effect of material coating of electroless nickel (EN) plating. The friction and wear experiments were performed using a four-ball machine tribo tester. Controlling the EN plating parameters plays an important role in the quality of coating. It depends on the wear scar rate of the coated material. So it is necessary to optimise the process parameters of EN plating. The experimental studies have been conducted under varying pressure, load and time on quality characteristics. In this paper, optimisation of process parameters using response surface methodology technique for EN plating was discussed.     

Structure‐Guided Design of Thiazolidine Derivatives as Mycobacterium tuberculosis Pantothenate Synthetase Inhibitors

The pantothenate biosynthetic pathway is essential for the persistent growth and virulence of Mycobacterium tuberculosis (Mtb) and one of the enzymes in the pathway, pantothenate synthetase (PS, EC: 6.3.2.1), encoded by the panC gene, has become an appropriate target for new therapeutics to treat tuberculosis. Herein, we report nanomolar thiazolidine inhibitors of Mtb PS developed by a rational inhibitor design approach. The thiazolidine compounds were discovered by using energy‐based pharmacophore modelling and subsequent in vitro screening, which resulted in compounds with a half maximal inhibitory concentration (IC₅₀) value of (1.12±0.12) μM . These compounds were subsequently optimised by a combination of modelling and synthetic chemistry. Hit expansion of the lead by chemical synthesis led to an improved inhibitor with an IC₅₀ value of 350 nM and an Mtb minimum inhibitory concentration (MIC) of 1.55 μM . Some of these compounds also showed good activity against dormant Mtb cells.     

Defect Characterization Using Pulsed Thermography

Infrared Thermography is one of the advanced NDE methods that is becoming attractive due to its ability to inspect non invasively large areas in short times and provide full field images in a non contact nature. While initially the method started as a qualitative technique for defect detection alone, with the advent of lock in and pulsed techniques, quantitative defect detection was made possible. While these techniques have been applied in case of ceramics and composites for defect quantification, defect sizing and quantification using these methods have not been systematically attempted in case of stainless steels. A systematic study has been undertaken to evaluate the accuracy of these empirical Pulsed Thermography (PT) techniques for defect size and depth estimation in type 316 L austenitic stainless steels. Theoretical modelling based on finite difference analysis using Thermo Calc 6L software has also been done and the results compared.     

Effects of special nanoparticles on fuel cell properties of sulfonated polyethersulfone membrane

Polyethersulfone was sulfonated by changing the reaction time with sulfuric acid. The degree of sulfonation and ion exchange capacity were determined. Sulfonation of polyethersulfone was confirmed by FT-IR analysis and a new peak at 1025 cm^?1. Inorganic materials such as carbon nanotubes, graphene, and kaolinite nanoparticles were synthesized. The effects of three nanoparticles on thermal stability and water uptake of sulfonated polyethersulfone were investigated. The morphology of membranes were also altered due to the addition of inorganic materials. The proton conductivity of the modified membranes increased with respect to increase in relative humidity.     

Self‐assembled centimetre‐sized rods obtained in the oxidation of o‐phenylenediamine and aniline

Morphologically well‐defined rods of approximately 1 cm in length are effectively and economically obtained by mixing ortho‐phenylenediamine (30 mmol L^?1) with ammonium persulfate (12.5 mmol L^?1) in an acidic solution (0.37 mol L^?1 HCl) at room temperature with and without the presence of 50 mmol L^?1 aniline. These self‐assembled, morphologically uniform products can be potentially scaled up and used as morphological templates to fabricate well‐defined structures of other materials such as conducting polymers. The products were characterized using Raman, UV‐visible, high‐resolution NMR (¹H and ¹³C) and mass spectroscopies, X‐ray diffraction, scanning electron microscopy and elemental analysis. Apart from certain differences in visual appearance and in X‐ray diffractograms, other analytical data suggest that there are no structural changes upon addition of aniline into the reaction mixture. NMR and mass spectra imply that all syntheses carried out either with or without aniline result in a mixture of two products, attributed to 2,3‐phenazinediamine and 3‐aminophenazin‐2‐ol. A formation mechanism based on hydrogen bonding and π–π stacking has been proposed. © 2015 Society of Chemical Industry     

First-Principles Investigation on Electronic Transport Properties of Tungsten Nitride Nanoribbon Based Molecular Device

The electronic transport property of tungsten nitride nanoribbon-based molecular device is investigated using density functional theory. The study on electronic transport properties are discussed in terms of device density of states and transmission spectrum of the nanoribbon. The scattering region of the nanoribbon is placed between the electrodes. For different bias voltages, the transport properties are studied. The contribution due to various orbitals leads to the peak maximum in device density of states. The transmission spectrum and transmission pathway provides insight to the transmission of charge under various bias conditions. The maximum peak in the transmission spectrum corresponds to the variation in transmission of charge with different bias voltage. The reported results will pave the way to improve the performance in the field of nanoelectronics.