Table of Contents - Volume 5 Number 1

Nickel cobalt manganese iron oxide (NCMF) is a good piezo magnetic material and lead zirconium titanate (PZT) is a good ferro electric material. The composites prepared from NCMF and PZT materials show good magneto –electric effect. In the present work, nano particles of NCMF (crysallites size ~. 13.5 nm ) were synthesized by hydrolysis process and PZT (17nm ) were obtained by soild state reaction methods . Magnetic behavior of NCMF and electrical behavior of PZT materials were also studied .Resistivity of the materials was measured and magneto electrical study of the composites was made .Magneto –electric composite of piezo magnetic ( 60% NCMF) and ferro electric (40% PZT) were prepared. On the application of magnetic field , piezo magnetic phase undergoes strain , which applies stress on ferro electric phase and as a result of this voltage is developed across the sample. It was observed that magneto electric effect produced by the composites prepared from nano particles was lower than that of produced from composites prepared from commercially available(coarse size) samples.

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Study of kinetics is very important in chemical process industries. Esterification process is very common in chemical industries in the literature. There are number of industrial application of Esterification which is discussed and the advantage of studying the kinetics of any Esterification reaction is that 1) All these reactions are empirically found to be of second order. 2) All these reactions have similar mechanism. In this research, the study of kinetics of Esterification reaction involving acetic acid and n-Butanol as reactant using sulfuric acid as a catalyst. Various experimental runs using laboratorial batch reactor have been conducted applying different combinations of temperatures, mole ratio and catalyst concentrations and finally a kinetic expression, as a function of these parameters, has been investigated.

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The vibrational frequencies and molecular geometry of the title compound are examined theoretically using the density functional theory (DFT) B1LYP, B3LYP, B3P86 and B3PW91 methods. For vibrational frequencies, the correlation coefficients obtained for B1LYP, B3LYP, B3P86, and B3PW91 methods are 0.998, 0.999, 0.998 and 0.998, respectively. B3LYP method provides most satisfactory correlation (CC=0.999) between experimental and calculated fundamental vibrational frequencies. For bond length correlation coefficients for B1LYP, B3LYP, B3P86 and B3PW91 methods are 0.997, 0.996, 0.994 and 0.995, respectively. For bond angle correlation coefficients for B1LYP, B3LYP, B3P86 and B3PW91 methods are 0.954, 0.952, 0.978 and 0.976, respectively. B1LYP and B3P86 yields highest correlation (CC=0.997 and 0.978) for bond length and bond angle, respectively.

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Sol-gel derived silica and titania doped silica films were fabricated by spin coating on silicon substrates. The work primarily deals with the influence of various sol-gel processing parameters such as addition of base catalyst, water to precursor ratio and sol pH on the gel times and consequently on the film thickness. The viscosity of the sol increases gradually with time and then attains a large value very rapidly for a given amount of base catalyst. Increase in the amount of base catalyst increase the gel time. As the molar ratio of water to precursor is increased the gel time initially decreases, however at large values of the ratio the gel time increase and the resulting films are thinner. Titania doped silica films were also fabricated. The thickness of silica films doped with 5.25 mol% titania decreases with spin speed.

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In order to extent the rheological behaviour of protein-surfactant systems, the viscometric studies on gliadin with sodium dodecyl sulphate (SDS) and cetyl pyridinium bromide (CPB) were made and the effect of pH and temperature on viscosity behaviours were studied. Studies show a minimum point, which corresponds to the isoelectric pH (5.20) of these solutions, has been explained to be due to the contacted state of the molecule caused by the attractive forces between the balanced positive and negative charges on the protein molecule. On either side of isoelectric point, the viscosity depends on factors such as hydrodynamic volume, net charge on the molecule, existence of free ions in the solutions. It has been shown that the interaction of protein molecule with cationic and anionic surfactants depends on the pH-values of protein-surfactant system.

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Investment casting is a specialized foundry process, in which a shell is built over a wax pattern where the shell is used as a mold and the molten metal as a cast. The major equipment required for this process are: Furnaces for melting, shell firing and preheating, core debinding and sintering;injection molding machine, autoclave, finishing and fettling equipment, inspection and quality control equipment, shell room equipment, cluster room equipment, die design and fabrication equipment, air cooling and material movement equipment.The process is an NNS (Near-Net Shape) casting process producing high quality products. It uses raw materials like highly reactive metals and alloys, wax, colloidal silica, ceramic sand and preformed cores. The criteria for selecting equipment in various shops depends on the process and the raw materials used. The capacity of the equipment should be enough to feed intermediate products in sufficient numbers for the next stage. The time schedule in each shop is different. A foundry can decide on the degree of automation in each shop, balancing higher quality against increased cost. Similarly, the decision to use centralized AC or air-cooling will depend on the cost factor. The paper discusses the selection criteria for each shop of the investment-casting foundry.

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Microwave measurements have been carried out on the industrially important rubber and polymer materials to study their dielectric behavior in X and K bands using microwave test benches equipped with Klystron and Gunn oscillators respectively and guided with rectangular wave guides. A decrease in dielectric constant with increase in microwave frequency has been observed for all samples. Some rubber materials were reinforced with carbon black as the reinforcing filler and vulcanized with sulphur as the principle vulcanizing agent in the industrial lab and their change in dielectric behavior was studied at microwave frequencies. The rubber materials after being reinforced and vulcanized have a high dielectric constant, low dielectric strength and hence have better electrical conductivity. One of the polymers Nylon 66 also showed an increase in dielectric constant after being reinforced with 30% glass fibre. To improve the applications of rubber derivatives, a blend is made between any two already available rubber materials which are thermodynamically compatible to one another. The dielectric behavior of two such polymer blends viz, NR+BIIR and NR+Reclaim was studied in the microwave frequency region. From the results obtained, it is observed that the electrical conductivity of the rubber derivatives increase after blending. Hence blending is a very important technique to improve the electrical properties of rubber materials.

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The Cu (II), Ni (II) complexes of Schiff bases derived from 2-Phenyl-3-{[(1E)-1-(3-oxo-3H-benzo[h]chromen-3-yl)ethylidene]amino}quinazolin-4(3H)-one have been synthesized and characterized by analytical data. The complexes are monomeric, possess in 1:2 (metal: ligand) stoichiometry and are non-electrolytic in nature. The Cu (II) complexes have been characterized by thermal analysis and X-ray diffractometry. The ligand and its Ni(II) complex have been characterized by powder X-ray diffraction. The thermal analysis of Ni (II) complex has also been carried out.

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The paper deals with synthesis of nanocrystalline La0.7 Sr0.3 Mn O3 (LSMO) and BaTiO3 (BT) powder via hydroxide co-precipitation route. The particle size of the powder is determined using Williamson Hall method and is observed to be nearly 35 nm for LSMO and 120 nm for BT. To avoid occurrence of impurity phases the composites of LSMO and BT are formed at 1273 K using Bi2O3 as a sintering aid. The paper focuses mainly on synthesis and dielectric properties of LSMO and BT composites.

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Analysis of the electron and hole transport in the quantum dot laser diode has been carried out in this paper. The electron and hole quantum dot potential has been deduced using the transfer matrix method and an iterative method have been utilize for computation of Eigen energy. The Hamiltonian is very useful to approximate the extent of the wave function within the quantum dot. The over all Hamiltonian for the quantum dot has been obtained and the normalized Eigen frequency has been deduced in the paper which is very essential for the analysis of the radiated spectra within the quantum dot region.

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Nanopowders of Ba0.8Sr0.2TiO3 (BST) and BaZr0.3Ti0.7O3 (BZT) are synthesized using hydroxide co-precipitation method. The nanoparticles are used to form composites z BST + (1-z) BZT for z = 0.4, 0.5 and 0.6 with 2 wt% Bi2O3 as a sintering aid. The powders of BST, BZT and composites are subjected to the investigations of XRD, complex impedance and dielectric properties. The results on variation of dielectric constant are promising and suggest usefulness of composites as a RF dielectric material, in the paraelectric region.

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The electron transport phenomena are a very complex in a quantum structures. The quantization effect in the quantum well is analyzed by solving the Schrodinger equation using quasi-transmitting boundary condition method and transfer matrix method. The current density dependence of Eigen energy and quantum well width has been reported in this paper. The current density observed to be increasing nonlinearly with respect to Eigen energy and quantum well width has been. The transmission coefficient has been analyzed as a function of Aluminum mole fraction and quantum well width. The immense effect of Aluminum mole fraction has been observed over transmission coefficient, while the effect of the quantum well width is trifling.

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Multiple quantum well laser diode has shown the advantage over other semi-conducting heterostructure laser. The electron transport phenomenon makes the multiple quantum well laser diode most powerful from existing laser diode. The Schr?dinger equation has been solved to realize the electron confinement in multiple quantum well regions by using quasi-transmitting boundary method. The 30% of Aluminum mole fraction is taken for the analysis and the Eigen energy found to be 0.2356eV and 0.2070eV for three and four quantum well respectively.

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In the present investigation we have developed ammonia sensor using polyaniline film doped with poly (vinyl sulphonic acid). We have synthesized polyaniline by oxidative polymerization of aniline using ammonium peroxydisulfate on poly(methyl methacrylate) substrate in the presence of poly (vinyl sulphonic acid) for the development of ammonia sensor. The synthesized Polyaniline films were characterized by using UV-visible, FTIR, SEM and the electrical conductivity. The ammonia sensing behaviour of the synthesized film was studied by indigenously developed computer controlled gas chamber. The synthesized PANI film shows excellent sensing behavior for 50, 100 and 250 ppm of ammonia.

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Dc reactive magnetron sputtering technique was employed for deposition of copper nitride films on glass substrates under different sputtering pressures in the range 1x10-2 – 1x10-1 mbar. The influence of sputtering pressure on the structural and optical properties was systematically investigated.

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Analysis of carrier transport while moving through GaN multiple quantum well has been carried out through phonon scattering using Fermi Golden rule. Hole capture in a Gallium Nitride quantum wells has been carried out with hole-optical phonon scattering mechanism using semi-classical approach. Our analysis show that the hole capture time vary as a function of the excess energy, quantum well width, barrier width and aluminum (Al) mole fraction in the barrier layer. Strong dependence of hole capture time on mole fraction x in the barrier layer of AlxGa1-xN has been attributed to the variation of energy and barrier height. The form factor varies in an oscillatory manner with the change in energy.

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Crystals are pillars of modern technology. Without crystals there would be no electronics industry, no photonic industry, no optic fiber communications, very little modern optical equipment and some very important gaps in conventional engineering.Yttrium Samarium Dysprosium Gadolinium Oxalate (YSmDyGdOx) crystals were grown by gel method. Silica gel method is capable of yielding crystals of high optical perfection and wide morphology. The growing crystals are held in the gel medium in a strain free manner and at the same time nucleation and super saturation are well controlled.

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2,5 – disubstituted 1,3,4 –oxadiazoles are synthesized from hydrazine and the corresponding aromatic acids both in the presence and in the absence of clay catalyst.

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Electrochemical kinetics to the surface of the nucleation of pitting are examined. The role of its energy heterogeneity and kinetics of the auto-acceleration of the process of the local depassivation of the surface of metal, are discussed.

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Some nonlinear Rhodium- tetracyanoquinodimethan were synthesized from the reaction of different counters of Rhodium with tetracyanoquinodimethan. Chemical structure of the obtained products will be investigated and confirmed by using elemental analysis and spectroscopic techniques such as IR-, UV/Vis- and 1H-NMR spectroscopy. In addition, the molecular structure of the obtained products determined. Described synthetic condition results in a significant improvement in both yield and reaction time of Z- b -(1-substituted-4-pyridinium)-a-cyano-4-styryldicyanomethanide chromophores. A decomposition study of the zwitterionic chromophores in solution is also described. The non-isothermal decomposition of rhodium adducts was studied on heating to the formation of rhodium metal at 400?C in N2 atmosphere using thermogravimetry (TGA), derivatives thermogravimetry (DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), X-ray powder diffraction and IR spectroscopy were used for identification of solid decomposition products. The variation of the rate of heating was used to calculate the activation energy(Ea) and the frequency factor (ln A) for the dehydration and the decomposition processes. In addition, the enthalpy(DH), heat capacity (Cp) and the entropy (DS) changes were also calculated from DSC measurements. The final mass loss after complete decomposition was found to increase appreciably with increasing the heating rate.

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An approach to understanding compatibility between ramie fiber as reinforcement in polymer resin was pursued by investigation of the surface porosity and contact angle measurement. Treatment the fibers is a must to obtain optimal wettability and also intimate contact as a lock and key mechanism between the fiber surface and polymer resin. Fiber surface porosity was examined by BET (Brunaeur-Emmet-Teller) method. It was surprising that the fiber treated by silane (trimethoxymethylsilane) and methylethylketone (MEK) had a higher porous diameter and specific surface area compared to ethanol and acetone. Comparison of wetting process between polypropylene (PP) and epoxy resins were also provided. Improvement was also showed by optimum contact angle between the fiber and PP droplets. which had cos q H?0.939 Both polypropylene and epoxy resin have a good wettability which had contact angle q < 550. From the pull-out test, the fiber embedded in epoxy and polypropylene with embedded length 1 and 2 mm (approximate) showed that epoxy matrix had a lower interfacial shear strength (ISS) than PP. Fiber-matrix pull-out fracture mechanism indicated from SEM proved that fiber embedded in PP matrix had better bonding-ability except for untreated fiber-PP. In semi-empirical stress distribution data, it was also found that ineffective lengths of ramie-PPs were remain lower than ramie-epoxy. Finally, the effect of solvent based treatment and silane coupling agent to the fiber surface proving that hydrophilic ramie fiber and hydrophobic polymeric materials can be combined and interact together to build an intimate contact due to fiber surface topography and chemical/physical interaction to the polymeric matrix.

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This paper describes the adsorption of Zn(II) from aqueous solutions by commercial natural bentonite (NB). The contact time, pH of the solution, metal ion concentration, Temperature, adsorbent doses, bentonite treatment (calcinations of NB at 700?C and washing by deionized water to remove the excess salt from bentonite surface) on the adsorption process were examined. The washed and calcined bentonite samples were labeled by WB and CB respectively. The adsorption process follows pseudo-second-order reaction kinetics. The Langmuir and Freundlich models were used to describe the adsorption equilibrium of zinc on NB and the adsorption followed the Langmuir isotherm. The Langmuir and Freundlich constants for adsorption of zinc on NB were determined. This work discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions. The results show that adsorption behavior of NB was strongly depending on the pH. The optimum pH for adsorption was found to be 6.0. Also the adsorption capacity of NB for Zn (II) increases with increased bentonite dose. The adsorbed amount of Zn (II) on WB was increased by 100% compared NB and CB. The results generally showed that bentonite could be considered as a potential adsorbent for Zn(II) removal from aqueous solutions especially WB.

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In this article, basic ideas of the diffusion in the gases and liquids are presented. In the last part of it, the problem of diffusion in the concentrated mixtures- when the concentration of components is not considered minor admixtures- is examined. In this case, Onsager?s equations are utilized in molecular physics.

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Thermal conductivity is an important characteristic of materials in particular semi-conductors and ceramics. Since it varies within a wide range and is measured in a variety of methods, no commercial device has, so far, been established to measure thermal conductivity. Hence, it sounds necessary to develop a device to meet all needs of scholars in laboratory with a general application. Development of such a device, beside relevant calculations, is evaluated in this paper where thermal conductivity of a thermoelectric semi-conductor ingot (approximately 8 mm in diameter and 24 mm in length) at the range of room temperature is considered. At lower temperatures, thermal conductivity is almost invariant and measured in both comparative and absolute methods. Absolute value method is still widely used at temperatures below room temperature. A great deal of practical error is due to heat leakage via radiation, convection and heat transfer. Within the range of room temperature, heat leakage shares a smaller contribution in error, but not an ignorable one. At higher temperatures heat leakage plays more important role and increasing temperature makes it more and more difficult parameter to define. Hence, for fabricating a device for thermal conductivity measurement taking into the account the errors and the involved parameters it is necessary to review the scientist comments in this subject which. we have a coverage of their idea.

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The critical micelle concentration (CMC) as well as the diffusion coefficients of the synthesized NaAAS surfactant were determined and discussed. The voltammetry of probed ferrocene solubilized in NaAAS surfactant was investigated using three different electrochemical techniques such as cyclic voltammetry, rotating disk voltammetry and chronocoulometry from aqueous buffer carbonate solutions of pH 10. The CMC of NaAAS was found to be 4.0?10-4 M using both CV and RDV techniques. Chronocoulometry showed negligible adsorption contribution to the electrode surface (1.0?10-15 M). The apparent diffusion coefficients were estimated from RDV measurements and the real micelles diffusion coefficients were obtained. Reequilibrium considerations of ferrocene probe kinetics at the electrode surface was treated according to two different modes of slow- and fast-kinetics. The corrected diffusion coefficient values showed constancy at (4.69± 0.4)?10-7 cm2/sec in the concentration range from 20 to 200 mM NaAAS. The morphological features of NaAAS micelles showed globular self-assembled structure with no conversion to rod-like at higher NaAAS concentrations. The inhibition efficiency of carbon steel L52 was determined from 1 M HCl containing different NaAAS concentrations using weight loss measurements. The maximum inhibition efficiency was obtained at 4?10-4 M NaAAS corresponding to the predetermined CMC of the surfactant.

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Nanocrystalline tin sulphide (SnS) thin films has been synthesized using successive ionic layer adsorption and reaction (SILAR) technique. The films are phase pure and polycrystalline with crystallite size approximately ranging between 8-11 nm. The crystallite size was measured using X-ray line broadening method. The variation of structural property with increasing thickness has been studied. Complete oxidation to tin oxide was found due to heat treatment at 400oC for one hour. The electrical characterization was carried out using conventional DC two-probe technique. An activation energy barrier value of 0.28 eV was observed, which can be associated with deep acceptor levels due to excess tin atoms.

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An experimental study was conducted to evaluate fracture toughness of metal matrix composite (MMC). The material was a 12,10,7.5 mm thick extrusion of 2124 aluminum alloy with 10 % Sic particulates. Specimen configuration and test procedure conformed to ASTM E399 Standard for compact specimens. It was found that special procedures were necessary to obtain fatigue cracks of controlled lengths in the preparation of precracked specimens for the MMC material. Fatigue loading with both minimum and maximum loads in compression was used to start the precrack. The initial precracking would stop by self-arrest. Afterwards, the precrack could be safely extended to the desired length by additional cyclic tensile loading .Test results meet practically all the E399 criteria for the calculation of plane strain fracture toughness of the material. A valid K1c, value of the Sicp/Al composite was established as K1c = 25.19 MPa. The threshold stress intensity under which crack would cause to grow in the material was estimated as A K1c = 2 MPa R = 0.09 using the fatigue precracking data. Fractographic examinations show that failure occurred by the micromechanicsm involved with plastic deformation although the specimens broke by brittle fracture. The effect of precracking by cyclic loading in compression on fracture toughness is included in the discussion.

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A complete vibrational spectrum analysis of 4-hydroxyacetanilide is performed. The wavenumbers are calculated on the basis of density functional theory using B3LYP/6-31G* basis set.Vibrational analysis indicates that the lowering of stretching wavenumbers of methyl group due to electronic effects simultaneously caused by inducation and hyperconjugation is due to the presence of the oxygen atom. Comparison of the observed fundamental vibrational wavenumbers of 4-hydroxyacetanilide with calculated results is found in agreement with the experimental data. The predicted infrared intensities and force constants are reported.

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Interaction of electromagnetic waves with the materials of planet earth provides the information for microwave remote sensing. From the reflected wave it is possible to reveal the information, which is useful for the measurement of dielectric properties. The dielectric properties of material are function of its chemical constituents and physical properties. Measurements of real (e') and imaginary (e") parts of the complex dielectric constant (e*) of soil with varied moisture content were made at 9.85 GHz. T

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In this study multi-pass zone refining technique was employed to purify indium metal from 3N+ to 5N6 purity level and the refined samples were characterized for their purity and crystalline quality. Major impurities that were targeted for reduction by multi-pass zone-refining include Al, As, Bi, Ca, Mg, Sb, Si, Sn, Ge, Pb, Ga, Cu, Fe, Zn and Ag. The samples were initially homogenized by following a three-cycle melting (heating) and solidification (cooling) scheme. A five pass pre-stage zone-refining experiment(s) of five hours duration on pre-homogenized samples were conducted employing Instrolec 200 zone-refiner. Parameters such as heater temperature, traverse speed, coolant flow and time were optimized. Indium samples obtained from the pre-stage zone-refining process were chemically washed, cleaned and then loaded in the Instrolac PTFE sample tube for final an eight-pass zone refining process. Starting and final stage zone-refined indium samples were characterized by ICP-OES, ICP-MS and XRD. It was found that, the total concentration of impurities reduced from 91.43 ppm to 14.465 ppm after 5 passes and to 4.02 ppm (5N6-99.9996% pure) after 8 passes and the results are discussed.

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One of the most common remedies for excessive digestive fluid (stomach acidity) is antacid tablets, and dilute acetic acid (such as vinegar) with a pH of around 3.0 is a reasonably effective and inexpensive representative of the weak organic acids present in human body. This acid may then be employed for simple laboratory simulation of the biochemical processes associated with neutralization by commercial over-the-counter antacids to relieve gastric distress. The laboratory experiment of the dissolution of an antacid tablet in dilute acetic acid solution may be taken as an example of mass transfer with chemical reaction, and the mass transfer and reaction steps can be studied. In the present work, experiments were carried out to determine the mass transfer coefficients and the reaction velocity constant for different commercially available antacid tablets in dilute acetic acid solution. The model developed by Stuart?s [1], which is a lumped parameter model, has been tested and modified to suit the present-work conditions. Also, an independent model has been developed to take care of mass transfer and reaction steps of the process. The model parameters, have been evaluated.

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The elastic shear stiffness constants of solids, correlated with other cohesive properties, provide a valuable insight into the nature of atomic binding forces. The deviations between calculated and measured values of isothermal bulk modulus of alkali halides have motivated us to frame a model for calculating the same for rock salt and cesium chloride structure alkali halides. The present approach shall include the effect of many body Coulombian, Born-Mayer type overlap repulsive and van der Waals (vdW) interactions in the framework of rigid shell model (R.S.M.). We hope that our results will show excellent agreement with measured isothermal bulk modulus for all the alkali halides.

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The effect of extremely low frequency (ELF) electromagnetic field (EMF) (50 Hz 0.5 mT) on the activity of alpha amylase (EC 3.2.1.1) was studied. In addition factors effecting the enzyme activity, temperature, pH, substrate concentration were also investigated. Our results show there is an increase in the enzyme activity when it is exposed to ELF EMF and also the velocity of the reaction increases. But there is no significant effect on optimal temperature and pH under the presence of the electromagnetic field.

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The inhibition effect of Cetyl trimethyl ammonium chloride (CTMAC) on the corrosion of mild steel in 0.5M hydrochloric acid solution was investigated at different temperatures using weight loss measurement, electrochemical polarization and scanning electron microscopy. Weight loss measurement and electrochemical polarization curves revealed that this surfactant inhibits the mild steel corrosion and inhibition efficiencies up to 98% can be obtained. The inhibition efficiency calculated from these techniques is in reasonably good agreement. The observed corrosion data indicate that the inhibition of mild steel corrosion is due to the adsorption of the inhibitor molecules on the mild steel surface. The surface morphology of mild steel samples in absence and presence of the inhibitor was examined using scanning electron microscopy.

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The paper reports details on synthesis of nanopowders of La0.7Sr0.3MnO3 (LSMO) and PbZr0.5Ti0.5O3 (PZT) via hydroxide co-precipitation route. The method is found advantageous in respect of possibilities of chemically stabilizing the average valences of the divalent Mn ions in the LSMO product. Further the hydroxide precipitates are subjected to the thermo gravimetric studies to understand the temperature of the desired phase formation. It is observed that the single phase LSMO and PZT nanopowders could be synthesized at lower temperatures with average particle size of ~ 35nm and 50 nm respectively using this method. The particle size is calculated using Williamson-Hall plots and confirmed using SEM pictures.

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