Pure H2 Production by Decomposition of Methane Over Ni Supported on Hydroxyapatite Catalysts

The catalytic decomposition of CH₄ for the production of pure H₂ is carried out over Ni supported on hydroxyapatite [Ca₅(PO₄)₃(OH)] catalysts at 650 °C and atmospheric pressure. CH₄ decomposition activity is decreased with time on stream and finally deactivated completely. The physicochemical properties of the fresh catalysts are characterized by XRD, DTA/TG, TPR and SEM techniques along with CHNS analyses of the used samples. It is found that the 30 wt% Ni/HAp displayed higher H₂ production rates over the other Ni loadings, which is correlated with Ni metal surface area measured by O₂ pulse chemisorption. IICT communication number: 051211.     

Preparation and characterization of sodium bearing perovskite phases

Ceramic waste-forms constitute a major alternative to glass for immobilization of radionuclides in solid phase, with advantage of greater stability in the presence of water at moderate temperature. CaZrO₃ and SrZrO₃ with ABO₃ perovskite structure are suitable host matrices for fixation of sodium and neodymium. Three new phases with compositions Na_0.5Nd_0.5ZrO₃, Ca_0.44Na_0.28Nd_0.28ZrO₃ and Sr_0.6Na_0.2Nd_0.2ZrO₃ have been synthesized and characterized as orthorhombic phases. The crystal structure of Ca_0.44Na_0.28Nd_0.28ZrO₃ was derived from the crystallographic parameters of CaZrO₃ using X-ray powder diffraction data in the orthorhombic system by Rietveld profile method. Preliminary leaching studies carried out in a digestion bomb showed low leachability of sodium and neodymium in water at 70 °C from Ca_0.44Na_0.28Nd_0.28ZrO₃ matrix as compared to that from Sr_0.6Na_0.2Nd_0.2ZrO₃ matrix.     

Purified mesoporous nickel metal organic framework as electrocatalyst for hydrogen evolution reaction (HER) in basic medium

Metal organic framework or MOFs are found to be a good catalyst for hydrogen evolution in view of its excellent structural features like porous nature and well-defined morphology. This report describes the synthesis of Nickel-MOF prepared by solvothermal approach and further purified by a chemical process. Both impure and purified Nickel-MOFs are fabricated as electrodes for evaluating HER reaction. The performance towards electrocatalytic activity is affected due to the impurities present in the porous structure. In view of investigating the effect of activation/purification process towards morphology and in-turn HER activity, activation and purification is carried out to enhance the performance of MOFs. The electrochemical characterization proves high electrocatalytic activity for purified Ni-MOF with high rate kinetics towards HER than impure Ni-MOF. The Tafel slope of purified Nickel MOF is estimated to be 73.7 mV/dec with a low charge transfer resistance of 1.84 Ω, whereas the unpurified Ni-MOF shows 87.47 mV/dec and 3.85 Ω. Results show that pure Ni-MOF has abundant catalytic active edge sites and obeys Volmer-Heyrvosky mechanism with makes desorption of hydrogen as rate determining step.     

Design and Implementation of Hybrid Compression Algorithm for Personal Health Care Big Data Applications

Wireless Personal Communications - Advanced telemedicine requires the gathering of big data through wireless body area network or internet of things based applications. These networks perform...     

Metallurgical Analysis of Cracked Redundant Valves for Propellant Flow Control in the Attitude Orbital Control System of a Satellite

Attitude Orbital Control System (AOCS) thrusters, used in Indian satellites employ Latchable Series Redundant Valves (LSRV) for propellant flow control. The valve body has a major component called bobbin, which comprises four parts, three parts made of AISI 304L stainless steel and one part of AISI 446 stainless steel. About 150 bobbins were electron beam welded and one, from a group of thirty bobbins, developed a crack in the HAZ of one of the face welds. Detailed analysis revealed that the crack was due to stress-assisted cracking phenomenon. The stress induced by press fitting of a part in between other two parts of valve was primarily responsible for the cracking.     

Synthesis of MnWO4 nanorods and its electrical and electrochemical properties

The MnWO₄ nanorods were successfully synthesized by surfactant assisted ultrasonics method and characterized its structural (XRD), morphological (SEM) electrical (solid state impedance) and electrochemical (CV) properties. The X-ray diffraction patterns inferred the formation of highly crystalline monoclinic structure of MnWO₄. The formation of nanorods with the aspect ratios of 30–40?nm were reveals from SEM image. The maximum d.c. electrical conductivity was found to be 4.40?×?10^?5?S/cm at 570°C for MnWO₄ nanorods prepared by surfactant assisted ultrasonic method. The quasi-rectangular behavior of cyclic voltammogram inferred the supercapacitive behavior of the prepared MnWO₄ nanorods.     

Experimental study of hydrous ethanol gasoline blend (E10) in a four stroke port fuel‐injected spark ignition engine

Performance, emissions and combustion characteristics of a port‐injected engine fuelled with hydrous ethanol gasoline blend (E10 ‐ 10% of hydrous ethanol by volume in gasoline) were compared with gasoline operation. Hydrous ethanol blend produced higher power output with lean mixtures at part throttle condition. Higher flame velocity and wider flammability limits of the blend resulted in lower cycle‐by‐cycle variations in indicated mean effective pressure as compared to gasoline. Hydro carbon emission was also lower due to the oxygen available in the fuel (E10), which enhanced the combustion rate. Higher latent heat of evaporation of the ethanol blend and water present in it resulted in lower in‐cylinder temperature, which in turn led to lesser NOx emissions. Thermal efficiency with the blend was higher in the leaner operating conditions than gasoline. Not much difference in performance, emission and combustion characteristics between neat gasoline and E10 were observed at full throttle operation. On the whole, hydrous ethanol blends can be used as a fuel with good performance and low emissions at part load condition. Copyright © 2012 John Wiley & Sons, Ltd.     

Influence of blockage and upstream disturbances on the performance of a vortex flowmeter with a trapezoidal bluff body

Experimental investigations are conducted on vortex flowmeter with the differential wall pressure measurement method. The bluff body employed is trapezoidal in shape and water is used as the working fluid. Three different blockages (0.14, 0.24 and 0.3) are considered in this study. The performance of the vortex flowmeter is studied both under fully developed condition and in the presence of flow disturbances. The flow disturbance is created using 45° swirl generator and gate valve placed at different upstream distances. The performance of the flowmeter is also evaluated in the presence of a Laws Vanes flow conditioner placed downstream of the swirl generator. The blockage ratio of 0.3 is found to be the best among all the blockages studied under both disturbed and undisturbed conditions.     

Minimally invasive injectable short nanofibers of poly(glycerol sebacate) for cardiac tissue engineering

Myocardial tissue lacks the ability to appreciably regenerate itself following myocardial infarction (MI) which ultimately results in heart failure. Current therapies can only retard the progression of disease and hence tissue engineering strategies are required to facilitate the engineering of a suitable biomaterial to repair MI. The aim of this study was to investigate the in?vitro properties of an injectable biomaterial for the regeneration of infarcted myocardium. Fabrication of core/shell fibers was by co-axial electrospinning, with poly(glycerol sebacate) (PGS) as core material and poly-l-lactic acid (PLLA) as shell material. The PLLA was removed by treatment of the PGS/PLLA core/shell fibers with DCM:hexane (2:1) to obtain PGS short fibers. These PGS short fibers offer the advantage of providing a minimally invasive injectable technique for the regeneration of infarcted myocardium. The scaffolds were characterized by SEM, FTIR and contact angle and cell-scaffold interactions using cardiomyocytes. The results showed that the cardiac marker proteins actinin, troponin, myosin heavy chain and connexin 43 were expressed more on short PGS fibers compared to PLLA nanofibers. We hypothesized that the injection of cells along with short PGS fibers would increase cell transplant retention and survival within the infarct, compared to the standard cell injection system.