Search

Glass ionomer cement is used as a restorative material. This study evaluated some physical properties such as specific heat, thermal conductivity, vickers hardness and breaking strength of Glass ionomer cement (GC Fuji II - Tokyo). The specific heat and thermal conductivity were determined using the principal of method of mixtures and Lee's apparatus respectively. Micro hardness measurements were performed using a Vickers cum Brinell hardness tester and measurement of breaking strength was carried out using a universal testing machine, operated at a head speed of 10 mm per minute. Glass ionomer cement has several desirable properties such as high specific heat, low thermal conductivity and thermal diffusivity apart from greater Vickers hardness and breaking strength. In presence of these advantages it may be a cement of choice for filling of cavities. [ABSTRACT FROM AUTHOR]

Cryogenic treatment has been recognized by a few methods for expanding apparatus life of numerous cutting instrument materials, hence enhancing efficiency essentially. However genuine components which ensure better instrument execution are as yet questionable. Concentrates on cryogenically treated HSS instruments demonstrate microstructural changes in material that can impact device lives. However little research has been done on other cutting apparatus materials. Cryogenic treatment of carbides presently can't seem to be widely contemplated. This work expects to contemplate the impact of cryogenic treatment on M2 and D2 steels. It is an extension for subzero process and It is the latest technology. The objective of this lecture is to explain the basic transformation of structures and the conversion of retained austenite into martensite and martensite into tempered martensite which in turn include the properties like longer part life, minimize failure because of cracking, enhanced warm properties, better electrical properties including less electrical protection, lessened coefficient of friction, minimal creep and walk, enhanced evenness, and less demanding machining. This retained austenite into martensite is the most important type of transformation i.e. transformation requires diffusion for the changes in crystal structure to occur. The effect of cryogenic process, subzero process, other heat treatment process and the types of heat treatment furnaces structural changes in heat treatment process are studied. [ABSTRACT FROM AUTHOR]

Microwave-assisted solvothermal (MAS) process is still in its infancy, wherein the effect of various process parameters are not thoroughly studied and yet to be established. This lack of understanding renders less than satisfactory reproducibility of the physical and electromagnetic characteristics of the deposited film. This work explores the effect of precursor solution preparation protocol on the microwave-heating mechanism, which in turn, impacts the rate of film deposition of Manganese Zinc Ferrite. A key pre-deposition step, sonication time – required to dissolve the solute precursors into the polar solvent or solvent mixture – was found to have significant impact on the quality and the reproducibility of the deposited film. Thus, keeping the deposition parameters constant (deposition time and microwave power) for all experiments, the sonication time was systematically varied to investigate its effect on the deposited film. It was evidenced that the pre-deposition sonication time of the solution affects the quantity of the volatile solvent in the solution which subsequently changes solution's effective loss tangent value, thereby affecting the film quality due to changes in heating rate while microwave irradiation assisted deposition. Furthermore, to affirm the impact of solution loss-tangent, solvents with different loss-tangent were mixed at different proportion before MAS deposition process. The deposition rate found to be varied from 10 nm/min to 120 nm/min by increasing the sonication time from 30 min to 75 min. Moreover, it was evinced that the high rate of deposition yielded a relatively rough and porous film that has a tendency of delamination. [ABSTRACT FROM AUTHOR]

Nanofluids have a great attention because it has an enormous potential to improve the efficiency of heat transfer systems owing to its high thermal conductivity. In this work, iron oxide nanoparticles were synthesized using cost-effective chemical method. The nanostructured iron oxide powder were characterized by various techniques viz., X- ray diffraction (XRD), Scanning Electron Microscope (SEM) etc. The iron oxide based nanofluids of different concentrations in the range 0.02%, to 1.8% were prepared. The size of nanoparticles used was in the range 20-50 nm. A comprehensive correlation of ultrasonic velocity and thermal conductivity is proposed based on experimental observations. The effect of concentration on ultrasonic velocity, compressibility and on thermal conductivity was studied. Such approach can be useful in studying the relationship between various properties of nanofluids such as ultrasonic velocity, thermal conductivity, electrical conductivity, compressibility etc. [ABSTRACT FROM AUTHOR]

Currently, K0.5Na0.5NbO3 (KNN) based ceramics are the most promising family of lead-free piezoelectric. The composition [(K0.5−x/2 Na0.5−x/2Lix) NbO3 (x=0.01, 0.05, 0.07): LKNN] have been fabricated by standard solid-state reaction method. X-ray diffraction analysis of samples show composition dependent structural changes. The structure is found to be orthorhombic for x=0.01 and x=0.05. A morphotropic phase boundary between orthorhombic and tetragonal phases is found for x=0.07. LKNN ceramics with x=0.01 exhibits enhanced electro strains properties with dynamic d33* value of 418 pm/V, and a remnant polarization (Pr) of 12.6 µC/cm2. [ABSTRACT FROM AUTHOR]

In this work, we present the synthesis and characterization of nanoparticles suitable for semiconductor applications using a simple and economical sol-gel process. ZnO-CuO is the potential material because of its high thermal stability and low cost. Properties of the ZnO-CuO nanocomposites are size dependent and when the particle size is reduced to the nanometer scales it shows some novel properties. Sol-Gel method is a good method to synthesis ultrafine metallic oxide nanocomposites and has been widely used for preparing nanoparticles at very low temperatures. Nano- structured ZnO-CuO has been characterized by using various techniques like XRD, SEM, and DSC-TGA. The phase transformation was investigated by an X-ray diffractometer (XRD). The microstructure was characterized by a scanning electron microscope (SEM). DSC-TGA analysis was used to investigate the thermal properties of the material. [ABSTRACT FROM AUTHOR]

Nanostructured Ni1-xZnxFe2O4(x = 0.4, 0.5 and 0.6) samples are prepared by the auto-combustion method. The compounds are formed in the cubic spinel phase without any impurity as confirmed by the XRD data. Increase in lattice parameters and volume of the unit cell with the Zn content is observed which is due to the larger ionic sizes of Zn2+ (0.74 Å) and Ni2+ (0.69 Å) when compared with that of Fe3+ (0.60 Å). The crystallite size increased with the Zn content. FESEM analysis reveals a non-uniform size distribution in grain sizes with the Zn content. All the prepared compounds maintained (Ni, Zn) and Fe stoichiometry in the ratio close to 1:2 as observed from the EDAX measurements. Magnetic properties are investigated using a VSM magnetometer. The magnetic parameters, such as saturation magnetization (Ms), coercive field (Hc), remnant magnetization (Mr) and Bohr magneton (μB), are determined. The saturation magnetization decreases gradually with increase in the Zn concentration. [ABSTRACT FROM AUTHOR]

In the present work, Nickel (Ni) doped molybdenum disulfide (MoS2) has been synthesized via a facile one step hydrothermal method using ammonium molybdate tetrahydrate [(NH4)6Mo7O24.4H2O], thioacetamide [CH3CSNH2] and nickel metal powder as precursors. The structural properties of the synthesized material were characterized by Powder X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR). Indexing of the peaks in the XRD plot of the material indicates the formation of 2H- MoS2 crystal structure. There is not much difference between 2H- MoS2 XRD plot and Ni:MoS2 XRD which confirms the successful Ni doping in the molybdenum sites of MoS2. Presence and percentage of doped nickel in the sample has been determined by Energy Dispersive X-Ray Analysis (EDX) characterization for the elemental analysis. Scanning Electron Microscopy (SEM) has been used for morphological studies. Crystallite size and lattice strain of the prepared sample has been obtained by the Scherrer method and W-H plot method respectively. Capacitance performance of the material has been studied using electrochemical workstation.For the analysis of thermal properties, Differential Scanning Calorimetery (DSC) and Thermo-Gravimetric Analysis (TGA) techniques have been used, which shows that the material has good thermal stability. [ABSTRACT FROM AUTHOR]

The synthesis of silver nanoparticles (AgNPs) has drawn attention over the past few years owing to their physico-chemical and optical properties. In the present investigation, synthesis of AgNPs using Punicagranatum(PG) peel extract was mediated using microwave irradiation. The duration of microwave irradiation and the concentration of AgNO3 and PG peel extract wereoptimized for the better yeild of AgNPs. The synthesized AgNPs were characterized by routine analytical techniques like UV- Visible, FTIR, DLS XRD and TEM. Under optimal synthetic conditions, the Zeta potential, average diameter and polydispersity index of AgNPs synthesized were-30.5 mV, 10±2nm and 0.224 respectively. Phytochemicals present in the extract help to reduce silver salt to metallic silver and act as a stabilizer in the synthesis of AgNPs. The synthesized AgNPs are not only showed good catalytic activity in the reductions of p- nitrophenol, methylene blue and congo red, but also showed antibacterial activity against gram positive and gram negative bacteria. [ABSTRACT FROM AUTHOR]

Cubic Li7La3Zr2O12 garnet electrolyte is the most studied solid electrolyte material due to its high ionic conductivity (10-4 S/cm) and large electrochemical stability window. It is difficult to stabilize the cubic phase of Li7La3Zr2O12 at room temperature without any doping element. Doping of different supervalent cations at the lithium and zirconium sites to stabilize the cubic phase of Li7La3Zr2O12 electrolyte has been studied by different research groups. In the present study Ce3+ substituted Li7La3Zr2O12 has been prepared by solid state reaction method in different compositions. The structural and transport properties of as prepared electrolyte have been studied by powder XRD and AC impedance spectroscopy. The conductivity values obtained for Ce3+ doped Li7La3Zr2O12 are considerably low as compared to pure cubic Li7La3Zr2O12 electrolyte which may be due to the lower ionic radii of cerium as compared to lanthanum. [ABSTRACT FROM AUTHOR]

Enhancing the thermal conductivity of a heat transfer fluid with the incorporation of nanomaterial is a widely known technique to achieve an efficient cooling system where such fluid, incorporated with nanomaterial is popularly known as nanofluid. However, the complexities in synthesizing the desired nanomaterial sand difficulties in incorporating them to the heat transfer fluid due to their poor dispersion ability opens up huge scope for carrying out further research in this field. Therefore, in the current work, we report, a simply synthesized amorphous carbon nanotubes (ACNT) and alumina (Al2O3) nanoparticle based nanocomposite that can easily disperse in engine oil (a class of heat transfer fluid) and can significantly improve its thermal conductivity. In our work, ACNTs with the length of ⁓ 4 µm and diameter of ⁓ 200 nm was synthesized by simple solid state reaction method whereas alumina nanoparticles with the dimension of ⁓50 nm were separately synthesized by sol-gel method. Then the nanocomposite was prepared by simply mixing them in liquid medium, followed by drying. Structural characterizations were carried out through x-ray diffraction, field emission scanning electron microscopic and high resolution transmission electron microscopic studies. The nanofluid was formulated by dispersing the nanocomposite in the base fluid (engine oil) with variation in loading and subsequently thermal conductivity was measured by Transient Hot Wire (THW) method. The maximum improvement in the thermal conductivity of ⁓ 20% was obtained with 0.04 vol. % of nanocomposite loading. So, all in all, it can be stated that ACNT and alumina naoparticle based nanocomposite was successfully prepared and its application in enhancing thermal conductivity of engine oil has successfully been shown. [ABSTRACT FROM AUTHOR]

From an extensive study, we proposed a perovskite solar cell device structure (ITO/ZnO/CH3NH3PbI3/C60/Au) to demonstrate the carrier transport and optical characterization using a commercially available software package. We used a distinct thickness of CH3NH3PbI3 active layer for the bandgap of 1.65 eV which delivers a power conversion efficiency (PCE) of 14.37% and external quantum efficiency about 82% respectively. Amongst the different thicknesses of perovskite layer, the 250 nm thick perovskite layer offers the highest open-circuit voltage of 0.807V, short-circuit current density (9.28mA/cm2), and fill factor about 0.7677. It accounts for quite remarkable significant improvement depicted in absorbance profile, mainly 86% for 250 nm thickness of the perovskite MAPI layer. Simultaneously, an average of 94% observed in the absorbance profile in sweeping angle cases from 0 to 85 degrees. [ABSTRACT FROM AUTHOR]

This paper presents studies on the thermal properties of the rare earth ion Pr3+ doped lead boro-tellurite (75PbO – (24-x) B2O3 –xTeO2– 1Pr2O3) glass systems which are highly suitable for fiber materials for non-linear applications like, laser, sensor, amplifiers etc. X-Ray Diffraction (XRD) analysis of the samples depicts the amorphous nature of glass. Glass transition (Tg) temperature and the crystallization temperatures (Tc) are determined using differential scanning calorimeter (DSC) technique. Results on XRD and DSC show that the investigated glasses are stable in nature. The stability of the glass is found to increase with the addition of TeO2 mole%. [ABSTRACT FROM AUTHOR]

Rechargeable Li-ion batteries although efficiently power small portable devices, implementation in electric vehicle mobility to assuage environmental concerns demand batteries possessing higher power densities and capacities while being compact and safer. Recent research is hence focused towards developing battery components that can sustain high charge-discharge rates while comprehensively addressing the safety issues. In our present research effort, attempts are made to investigate the role of different binders on the performance of nanostructured lithium titanate (LTO, Li4Ti5O12) anodes in half-cell configuration against Li-metal. Commercial nano-LTO, Super-P and polyvinylidene fluoride (PVdF) are used as reference materials for comparative appraisal. An endeavor is made to showcase the feasibility of water soluble binders: sodium alginate (Na-alginate) and sodium carboxymethyl cellulose (Na-CMC) for greener processing of the electrodes and evaluate the effect on specific capacity, reversibility, charge retention and adaptability towards faster charging rate in the half-cells assembled. Binders provide sufficient adhesion interconnecting the active particles as well as maintain proper contact with the current collector, thus imparting electrode integrity over multiple charge-discharge cycles. This apart, binders are understood to influence the conductivity of electrodes, electrolyte wetting behavior, formation of solid-electrolyte interface (SEI) and the charge-transfer across interfaces. A lower interfacial resistance can promote higher specific capacity, increase energy density, improve reversibility, etc. while restricting capacity fade even at high C-rates; and the role of binders is found to contribute significantly. Comprehensive analysis of electrochemical impedance data collected at the end of each galvanostatic charge/discharge cycle provided crucial clues in understanding the charge transfer behavior for the electrodes fabricated with the binders. [ABSTRACT FROM AUTHOR]

Modulation in resistance switching characteristics of TiO2 thin film fabricated on aluminum substrate is investigated under optical illumination. The average thickness of TiO2 thin film is about 200 nm. The current–voltage characteristics of the Pt/TiO2/Al structure show a good rectifying property with unipolar resistive switching behavior. This resistive switching behavior is observed to be modulated by optical illumination. Photo-carriers generated during optical illumination shifts the set and reset voltage to lower values. This study is helpful for exploring optical effect in metal oxides as multifunctional materials and its applications in non-volatile memory devices. [ABSTRACT FROM AUTHOR]

The SEM photographs on HITACHI S-4700 FE-SEM for Composite Solid Electrolytes 0.25Ba(NO3)2-0.75KNO3, 0.19Ba(NO3)2-0.81KNO3, 0.05Ba(NO3)2-0.95KNO3 and DSC (DSC-60-SHIMADZU)plots of Ba(NO3)2, KNO3 and their composites systems of 0.62Ba(NO3)2-0.38KNO3, 0.37Ba(NO3)2-0.63KNO3, 0.25Ba(NO3)2-0.75KNO3, 0.19Ba(NO3)2-0.81KNO3, 0.05Ba(NO3)2-0.95KNO3 mole percentages have been studied to understand the reason behind the enhancement of conductivity in these materials. Uniform distribution of particle size can be noticed in 0.25Ba (NO3)2-0.75KNO3, 0.19Ba (NO3)2-0.81 KNO3 comparing to other mole percentages. In 0.19Ba (NO3)2-0.81KNO3 particle size is found to be uniform and larger compared to other mole percentages, which would effectively reduce the grain boundary resistance and thus increases the conductivity [1]. The enhancement of conductivity in this system was explained as due to the increased concentration of defects in space charge region formed between the host and nano particles of dispersoid. [ABSTRACT FROM AUTHOR]

We have performed molecular dynamics simulations on binary FeXZr100-X (X = 88, 90) system to understand the glass forming ability by evaluating the short range order and viscosity. Our analysis has shown that in FeZr system the addition of Zr has enhanced the percentage of Fe centred <0,1,10,2> and <0,0,12,0> clusters. The evolution of Fe center clusters has played an important role in local structural transition along with other equally significant Zr-centered <0,3,6,4> and <0,2,8,4> clusters. Moreover, the viscosity was calculated from Green-Kubo approach and fragility parameter (m) was obtained by Vogel-Fulcher-Tammann (VFT) relation by measuring the slope of a logarithm of the viscosity versus temperature. The obtained value of m for both the system was found in agreement with the reported values m of the good glass former. From this, it may be suggested that Fe centered clusters influence the packing density of the glass and lower the m value which then leads an alloy to show better GFA. [ABSTRACT FROM AUTHOR]

Novel bio-inspired nanoarchitectured materials with surface functionalized properties have potential applications in various fields. Polymeric porous nanomaterials/particles/capsules are taking as a challenging task for surface porosity as payload for anticancer drugs and nanomedicines for drug delivery and cancer theranostics. The block copolymer of [(PLGA)-b-(PNIPAM)] is bio-inspired along with biodegradable, biocompatible and bio-safe (3B) polymers and these can help to design and develop potential carrier nanomaterial for biomedical and biotechnological applications. The polymers like [(PLGA)-b-(PNIPAM)] follow 3B formula and can easily functionalized. The surface functionalization of nanomaterial or particle or capsule surface profile can be modified based in the desired applications. The active functional groups present in the polymers lead to the self-assembly followed by the net-work formation capabilities. The interactions between polymer and inorganic, organic and metal nanoparticles has been examined through the following characterization tools FTIR, SEM, and TEM for functional groups, size, shape, morphology, surface profile. The PXRD, DSC, TGA has been performed for physical properties. The spreical capsules with size of ∼720 nm (in diameter) has been engineered and used drug delivery and release studies. The confocal microscopic imagning corroborates the ruptured and inhibited HepG2 cellular morphology with 62% inhibtion after 24 treatment with anticacner drug Toxol. These surface functionalized nanoparticles are recommended for drug delivery and for various cancer therapeutics. [ABSTRACT FROM AUTHOR]

Density Functional Theory (DFT) approaches is a very useful technique to evaluate the structural and electronic properties of the materials. Solid nano-composite polymer electrolytes based on poly (ethylene oxide) (PEO) and Ammonium Thiocyanate (NH4SCN) salt have been taken for study. The interaction between PEO and NH4SCN (electrolyte) in the subsequent step has been studied using DFT from the theoretical and computational calculations. The computational calculation of polymer electrolyte provides the electronic properties, stability, structural, vibrational properties of PEO, NH4SCN salt and composition of PEO with NH4SCN. Moreover, the frontier orbitals (HOMO- LOMO) configurations and energies were calculated for PEO, NH4SCN and the values are -4219.3446eV, -14918.3798 eV respectively. The interaction of PEO with NH4SCN shows the interaction energy is 0.1775 eV. Mulliken charge distribution and IR are also calculated. [ABSTRACT FROM AUTHOR]

KMgAlF6 belongs to group of such hexafluoro-aluminates like LiCaAlF6 and LiBaAlF6, where they replace AlO3-3 by AlF6−3. KMgAlF6 crystallizes in cubic system with space group Fd[inline-math]m. Very less studies regarding its luminescence properties and crystal structure are available in the literature. Fluorides are generally prepared by solid state reaction. Fluorides are sensitive to hydrolysis. Purification of fluorides is necessary to eliminate traces of water and to hinder the formation of oxyfluorides. These treatments makes the solid state techniques cumbersome and difficult. In recent years, some wet chemical syntheses for preparation of OH− free fluorides have been discussed. Hence, We have decided to try the wet chemical route for the synthesis of KMgAlF6 compound. X-ray diffraction pattern of our sample was compared to that of standard ICDD data in order to confirm the formation of the desired compound. XRD results confirmed the formation of KMgAlF6 in our sample. After XRD measurements, our sample was doped with rare earths such as Ce3+/Eu2+ activators. Procedure is same for preparing doped samples except that freshly prepared europium/cerous solutions(in the desired proportions) were added prior to the precipitation. Later, photoluminescence studies were carried out for KMgAlF6:Ce3+ and KMgAlF6:Eu2+. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) is technically and economically reliable alternative to the p-n junction photovoltaic devices. Recently, the energy conversion efficiency of DSSC has been reported to improve a lot using nanoporous electrode. Numerical modeling is effective strategies for depth understanding of the working mechanism of a solar cell. This paper illustrates the optimization of current density versus voltage (J-V) outcomes using MATLAB by varying the different physical parameter of DSSC like temperature (T), intensity(I), absorption coefficient (α) and thickness of electrode (d) in modeled simulation equation. Second order differential simulation equation has been used in present study for measurement of performance curve of Dye-sensitized solar cell. The current density versus voltage (J-V) curve for DSSC has also been calculated numerically using the internal variable such as diffusion coefficient (D), diffusion length (L), initial concentration of electrons (n0) and thickness of electrode (t). The current density versus voltage (J-V) curve. [ABSTRACT FROM AUTHOR]

Spacers are a key component of the gas-insulated structures. Most dielectric instances intensity collapses and ground flashover are attributed to distinguish the failures of spacer. Such Failures are due to non-uniformity distribution of electric field around the top of the spacer and high field tension at triple junctions. For a better electric field distribution, precise structure simulation of the spacers is important as it improves the component's existence. Rare pressure management results in problems such as moulding and manufacturing by shape modeling. In this paper, a graded high FGM insulating spacer is designed for a Single phase GIS for reduction of electric field stress. Stress in the electrical field for different values of high grading the FGM material is measured and the insertion of metal inserts is used to reduce the electrical field pressure. [ABSTRACT FROM AUTHOR]

The Ecofriendly, cost-effective bio-synthesis of gold nanostructures (Au NSs) were synthesized by using Daucus carota subsp. Sativusand Cucumis sativus extracts efficiently. The plasmonic peaks of Daucuscarota subsp. Sativus and Cucumis sativus extract synthesized Au NSs exhibited at λmax = 554 nm and λmax = 560 nm, owing to excite of surface plasmon vibrations of Au NSs. The formation of NSs is due to the ionization of phenolic groups of vegetable extract. These extracts act as to reduce and capping agents in the formation of nanostructures. Transmission electron microscope (TEM) images of Au NSs revealed that they are in spherical and triangle shapes. The spherical shape of Au NSs of average diameters is 51 nm and 53 nm respectively. The effect of NSs on the luminescence of Eu(TTFA)3 complexes was investigated with 350 nm excitation. Luminescence quenching is observed for Eu3+ with different concentrations of Au NSs in an exponential fashion. In both cases, the electric-dipole and magnetic dipole transitions are quenched with an increase of Au NSs. The quenching is occurring owing to the re-absorption of NSs. Nonlinear optical studies of metal NSs are estimated with a Z-scan technique using 800 nm, 110 fs pulses at 1 kHz repetition rate. Au NSs exhibited reverse saturable absorption (RSA) due to excited state absorption (ESA) and third-order nonlinear absorption coefficients for both Au NSs are of the order of 10−10cm2/W. Au NSs can be used as luminescent probes and optical limiters. [ABSTRACT FROM AUTHOR]

The present work reports structural and luminescence studies on Dy3+ doped borofluorophosphate (BFPDY) glasses prepared with the chemical composition of (40-x)B2O3 + 30P2O5 + 10ZnF + 10K2O + 10BaO + xDy2O3, where x = 0.1, 0.2, 0.5 and 1 mol% by melt quenching technique. The structural and optical properties of the prepared glasses were analysed by means of XRD, FTIR, UV-V is absorption spectroscopy and photoluminescence emission and excitation spectra. XRD results confirm the amorphous nature of glass and FTIR studies reveals the presence of various stretching and bending vibrations of different structural units within the sample. The optical absorption spectrum has been recorded at room temperature and different absorption transitions were obtained and it is found that the transition via 6H15/2→6P7/2 is more prominent. From the absorption spectrum, optical band gap energy, nephelauxetic ratio (β) and the bonding parameter (δ) were determined. Excitation spectrum was recorded in the region 300-500 nm by monitoring emission at 572 nm and characteristic excitation bands were observed. The band at 348 nm arising through the transition 6H15/2→6P7/2 shows maximum intensity. The photoluminescence spectra of the fitted glasses have been recorded at an excitation wavelength of 348 nm and the spectra contain two intense emission bands in the blue (483 nm) and yellow (572 nm) regions and a weak band in the red region (663 nm). Concentration dependent variations in emission intensities were analysed. It is observed from the emission spectra that the luminescence intensity increases with the increase in Dy3+ ion content up to 0.5 mol% beyond that it decreases due to luminescence quenching. The Y/B intensity ratio by varying the concentration of Dy2O3 is also studied. The emission intensity were characterized through Commission International d'Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for white light emission applications. [ABSTRACT FROM AUTHOR]

The present work reports the preparation and study of multiferroic Nd doped BiFeO3 (BFO) polycrystalline samples. The samples are prepared with sol-gel method. The x-ray diffraction measurements confirm the orthorhombic structure with Pnma space-group. Small amount of secondary phase is also observed. SEM and EDX have been used to study the surface morphology and weight percentage of the elements. The room temperature leakage current density (J-E) measurements indicate grain boundary limited conduction and Ohmic conduction mechanisms under lower and higher field regions, respectively. Ferroelectric (P-E& PUND) and Mössbauer spectroscopy measurements are also carried out and are discussed in the present paper. [ABSTRACT FROM AUTHOR]

The present research work, First principles calculations have proven to be outstanding tools to laboratory experiments in research because they can calculate some characteristics of a modeled system that are very hard to obtain experimentally. First principles calculations (CASTUP) also offer far greater ability to control and manipulate a system, providing the modeled system reflects the real system accurately. calculations and their applications in the research of positive electrode materials were studied. An economical and novel method for synthesis of Nano porous LiFePO4/C composite by glycine and urea assisted combustion method with fuel to oxidizer ratio Ψ =1. The average crystallite size of obtained LiFePo4/C composite from x- ray diffraction is 40-45nm. Morphological studies were done using scanning electron microscope the structure of the surface coated carbon and the material were investigated by Raman spectroscopy. The structure of the material at the molecular size scale has been investigated by FTIR transmittance and Thermal Analysis and stoichiometry analysis for Fuel to nitrate ratio for urea and glycine and for various molarities and there balancing equations and calculation for Enthalpy of combustion and adiabatic flame temperature results were presen [ABSTRACT FROM AUTHOR]

In the present work, ZnS/Graphene nanocomposite is prepared by solution mixing and sonication method. The thin films are prepared with homemade chemical spray pyrolysis system (CSP) by the colloidal spray coating method. ZnS/graphene nanocomposite thin film fabricated at the substrate temperature of 350°C. Uniform, adherent, highly crystalline, and transparent thin film obtained. The films characterised by UV-Visible spectroscopy, Photoluminescence, X-Ray diffraction (XRD), Energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The absorption spectrum of composite shows the blue shift in the absorption peak as compared to intrinsic ZnS thin film. The bandgap increased from 4.1eV (intrinsic ZnS at substrate temperature 350°C) to 4.9eV (ZnS/graphene composite at substrate temperature 350°C). The XRD and EDS analysis confirm the composite formation and purity of the samples. The SEM images show the uniformity of thin films with granules agglomerated structures. [ABSTRACT FROM AUTHOR]

Eu3+ and Tb3+ - activated Ba2SiO4 phosphors have been synthesized by using high temperature conventional solid state reaction method. All synthesized phosphors are characterized by X-ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Scanning Electron Microscope (SEM), Fourier-Transform Infrared Spectroscopy (FTIR) and Photoluminescence Techniques (PL). The X-ray diffraction patterns of the sample are indexed as orthorhombic structure. Elements are present in the composition are Ba, Si, O, Eu and Tb as confirmed from EDS. In the photoluminescence studies, Ba2SiO4: Eu3+ phosphor exhibits strong emission peak at 611 nm and Ba2SiO4: Tb3+ phosphor exhibits high intense emission peak at 546 nm under UV excitations. These peaks may be attributed to the transition 5D0 → 7F2 of Eu3+ ions and transition 5D4 → 7F5 of Tb3+ ions. The intensity of intense peaks are increasing with Eu3+ concentration increases as well as the high intense emission peak is moderated from blue region to green region with Tb3+ concentration increases. The CIE (Commission International de I'Eclairage) color chromaticity diagram confirms that the synthesized phosphors are emitting red and green color. Based on these results, these phosphors may be useful as red and green phosphors in the lamp as well as in the display devices. [ABSTRACT FROM AUTHOR]

Recently, glasses containing rare earth ions have evoked interest due to their potential applications in solid-state laser, display devices, sensors, reflecting windows, waveguides, 3D data storage devices etc. In particular the Sm3+ ions in host glass material exhibit broad emission bands due to 4G5/2 →5HJ (J = 5/2, 7/2, 9/2, 11/2) transitions in any host matrix. In order to obtain optimum emission characteristics for device applications, the characteristic features of host as well as concentration dependent studies of Sm3+ are essential. In this regard, a new series of Samarium doped Zinc Lithium Borate glass were synthesized and their optical properties were investigated. [ABSTRACT FROM AUTHOR]

The voltage induced in the coil (solenoid or inductor) depends on number of turns of coil, rate of change of flux and permeability of core material. It was observed that the induced voltage in a coil can be further increased, if the temperature of ferromagnetic core material is increased [1]. The variation of inductance and effective resistance of the coil in the presence of heated ferromagnetic cores and Coefficient of induced voltage, Coefficient of permeability for different ferromagnetic core materials also measured [5]. All these parameters were measured for ferromagnetic Mild Steel, Cobalt and Nickel as core materials in horizontal setup [2, 3, 4, 6] and in vertical set up. In this paper variation of induced voltage, inductance, effective resistance of the coil and Coefficient of induced voltage, Coefficient of permeability in the presence of heated ferromagnetic Mild Steel, Cobalt and Nickel as core materials are measured and reported in the vertical setup as comparative study [ABSTRACT FROM AUTHOR]

Influence of annealing temperature on resonance field, ESR line width, magnetic anisotropy, resonance frequency and magnetic properties were studied for Ni0.65Zn0.35Fe2O4. Sample with selected composition was synthesized using sol-gel synthesis using PVA as a chelating agent and annealed at different temperatures from 400°C-1100°C. Saturation magnetization gradually increases with annealing temperature up to 74 emu/gm at 1030°C and then decreases with further rise in annealing temperature. The highest coercivity was obtained at 750°C and decreases for higher annealing temperatures. The lowest ratio of Mr/Ms ratio maintained at 0.06 at 1030°C indicates the dependence of magnetostatic nature in domains with annealing temperature. A steady rise in anisotropy and resonant frequency was observed with increasing annealing temperature with a marginal drop at higher annealing temperature. [ABSTRACT FROM AUTHOR]

In the last few years, multiferroic materials are emerging as a material of choice to realize memory based devices, sensor based devices and optoelectronic based devices. Among the several multiferroic materials, bismuth ferrite (BFO) appears to be a potential candidate for photovoltaic devices due to its relatively lower optical bandgap (2.08 - 2.7eV) and large remnant polarization (90 µC/cm2). It is also suitable for memory devices due to the co-existence of different ferroic orders and a large remnant polarization. However, the practical application of this material is still hindered due to the inherent limitations which include large leakage current and pure phase formation of BFO compound. Keeping this view in mind, we have successfully synthesized the pure phase of BFO nanoceramics by adopting low temperature sol - gel synthesis route. Furthermore efforts were devoted to study the effect of annealing temperature and its duration on the structural, morphological and optical properties of these ceramics. The as-prepared samples were calcined at 400°C and subsequently annealed at various temperatures (500°C, 550°C and 600°C) for different durations (2h, 4h and 6h). Interestingly, the sample annealed at 550°C for 2h yielded pure phase of BFO ceramics and the average crystallite size of these ceramics was found to be increasing with both increase in annealing temperature and duration. The Fourier transform infrared spectra (FTIR) recorded for all these samples exhibited strong absorption bands in the range of 400 - 600 cm−1, which corroborated the perovskite structure of BFO nanoceramics. The microstructural analyses have revealed the existence of granular shaped grains with negligible porosity in all the samples studied. Furthermore, the samples annealed at higher temperatures for longer duration showed the agglomeration of the grains in the scanning electron micrographs. The optical bandgap was determined for all the samples prepared under various annealing conditions by Tauc's method. Interestingly, it was found that the value of bandgap of these ceramics could be tuned as a function of annealing temperature and duration. For instance, the value of the optical bandgap obtained for the pure sample annealed at 550°C for 2h was found to be 2.08 eV. Therefore, in this present investigation, the tailoring of physical properties of BFO nanoceramics by aforementioned thermal treatment could be beneficial for designing memory as well as photovoltaic devices. [ABSTRACT FROM AUTHOR]

Our past decade witness to the quick growth of Li-Ion battery industry in response to the growing needs of electronic and information industries. Lithium Cobalt Oxide used as Initial cathode material for Lithium batteries application it consist of high toxic nature, costly and with low energy density. Thus there need to develop new Li-Ion batteries to improve above characteristics along with efficiency and make it portable. So that can be used in electronics, transportation, and energy storage and especially in hybrid electric vehicles.LiMn1.5Ni0.5O4 is hence the best development seen so far. It is improved version of LiCoO2. It usually overcomes all the problem of older lithium batteries. The high initial capacity and good cycling behavior of LiMn1.5Ni0.5O4 powders calculated at higher temperatures are closely related with the higher crystalinity and retention of the spinel structure with cycling and hence proved that LiMn1.5Ni0.5O4 is far better than other batteries. For synthesizing LiMn2-xNixO4, we use sol-gel procedure. The electro chemical performances of prepared samples are tested. The crystalinity and lattice constants by X-Ray diffraction, thermal analysis by TGDTA, morphology by SEM and bonding between the atoms by FTIR were studied in this paper. [ABSTRACT FROM AUTHOR]

High voltage power equipment is becoming more compact and under high stress, resulting in loss of insulation. The construction of insulators plays a vital role in enhancing the system's reliability. For GIS, the solid supporting structures called spacers are vulnerable to increased stress and are concerned about their functionality. The point of contact of the conductor, gas and spacer called the triple point junction in the air-insulated bus duct is a highly stressed area and is responsible for significant insulation failures. GIS switchgear design requires comprehensive field distribution in the supporting structures called spacers, which is critical for the system's healthy operation. In this paper, high grade material is used for post form spacers with specific permittivity for controlling field stress distribution on the spacer surface. Electric field calculations for different grades are calculated and compared and the stress reduction is carried out with the insertion of metal inserts. [ABSTRACT FROM AUTHOR]

We present systematic investigations of tuning magnetic anisotropy, domain structure, magnetic, structural and electrical transport properties of Fe1-xNix thin films. All the films were prepared by DC magnetron sputtering directly on Si (100) substrate maintained at different substrate temperatures (TS). Fe1-xNix films deposited at ambient temperature exhibit disordered structure. With increasing TS, the degree of L10 ordering enhanced up to 250°C and then decreased due to the formation of A1 phase. As a result, the average surface roughness increased and consequently the electrical resistivity decreased with increasing TS. Saturation magnetization (MS) and anisotropy energy (Ku) increased progressively with increasing Fe content and exhibited a maximum of 0.91 T and 0.52 MJ/m3, respectively, for Fe51Ni49 thin films prepared at TS = 250 °C. Magnetic domain studies confirmed the existence of in-plane niaxial magnetic anisotropy in L10 ordered FeNi films. [ABSTRACT FROM AUTHOR]

A comprehensive simulation model is presented for the quantitative analysis of the carrier transport and optical properties of a trilayer OLED device (ITO/NPB/Alq3/TPBi/Al) structure. It is evident from the J-V curve and depicted when a turn-on (knee) voltage is 6 V, the mean current density and electrical input power is 10 µA/cm2 and 59 µW/cm2, respectively. The device performance factor-like external quantum efficiency (EQE) is 55-66% in the wavelength region 300 to 450 nm, 4.35 for Vbias=8 V, and 6% at 50 nm thick EML. Among the different thicknesses, a quite remarkable improvement for the 50 nm thick EML has luminance concerning charge density 10,000 cd/m2 and the bias voltage by about 700 cd/m2. The spectral irradiance for the OLED device is 0.06 Wm−2nm−1sr−1 maximum in the spectral region 400-760 nm. Thus, the CIE curve studied at a distinct angle and peak get shifted at different EML thickness that show the case of thickness dependence. This study also provides an effective way to further optimize the efficiency of the OLED device with a better suitable thickness. [ABSTRACT FROM AUTHOR]

Crystals of SnSe and SnSe doped with Cu have been synthesized by a direct vapour transport technique. The grown crystals have shiny faces and they do not suffer from the contamination of the transporting agent. The characterization of the crystals has been done by using the techniques of X-ray diffraction, Energy dispersive analysis of X-rays (EDAX), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and electron diffraction. An estimation of crystallite size, dislocation density and lattice strain has been made. In order to understand the mechanism of growth of the crystals, scanning electron microscope and transmission electron microscope have been employed. The crystallinity of the grown crystals has been confirmed by electron diffraction pattern. The implications of the results have been discussed. [ABSTRACT FROM AUTHOR]

The film-impregnated dielectric under operating conditions is subject to prolonged exposure to electric and thermal fields, as well as mechanical loading. In addition to critical partial discharges, the most serious drawback that impairs the film and condenser reliability in general is the deterioration of the electro-physical characteristics of the polypropylene film and liquid dielectric due to the gradual dissolution of the polymer in the liquid dielectric, which is determined by their chemical composition. This interaction of components, which was investigated in detail, has a thermo activation nature, which relates to the processes of rearrangement of atoms or molecules with the overcoming of potential barriers, and is manifested in the swelling of the polypropylene film with subsequent dissolution of the amorphous component in the polymeric component. As a consequence, irreversible structural changes of the film occur, which lead to a decrease in its electrical and mechanical strength, as well as to an increase in the dielectric loss of the liquid dielectric. Capacitor (Fig. 1 (a)) is designed to provide high-frequency communication at frequencies from 24 to 1500 kHz in power lines with a nominal voltage of 35, 110, 150, 220, 330, 500 kV AC 50 and 60 Hz. Coupling capacitor impregnated with environmentally friendly liquid - condenser oil. The short-circuits consist of capacitor sections (Fig. 1 (b)): a thin layer of dielectric is laid between two thin wide metal strips, and the dielectric film is placed on top and below the metal strips - capacitor covers. This paper gives the detail analysis of dielectric properties of capacitor paper. [ABSTRACT FROM AUTHOR]

In this paper the study of new approach to the construction of a transition matrix associated with first order matrix system of differential equations is applied in the control systems. This method is unique and is applicable to all problems that arise in control systems and the tedious calculations so far existing in literature will be condensed to less than half. [ABSTRACT FROM AUTHOR]

High voltage electrical systems are plagued by certain problems, such as high stress delivery and damage to insulation, which are necessary to ensure efficient network service High pressure on the spacer surface in a gas-insulated bus duct is a major factor influencing the insulation strength , particularly at the conductor, insulator and gas contact point (called triple junction).Research studies of spacer shaping have been found to be effective in managing pressure distribution but difficult in real-time applications. In this paper, for the regulated field stress division on the spacer layer, dynamically graded post-type spacer materials with dissimilar low graded permittivity are planned. Electric field calculations for low graded materials are performed and a uniform distribution of stress along the spacer is achieved by correctly designed metal inserts integrated in GIS. [ABSTRACT FROM AUTHOR]

Heat and mass transfer on the unsteady two dimensional MHD flow through porous medium under the influence of uniform transverse magnetic field in a rotating parallel plate channel has been investigated. A mathematical model is developed for unsteady state situations using slipconditions. Analytical expressions for the velocity, temperature and concentration profiles, wall shear stress and rates of heat and mass transfer have been obtained and computationally discussed with respect to the non-dimensional parameters. [ABSTRACT FROM AUTHOR]

There is a large increase in power demand and by using Flexible AC transmission systems (FACTS) controllers various steady state control problems in power system can be resolved. In FACTS devices converters form the main component. Apart from the existing multilevel inverters here a new design of inverter is proposed which aims at reducing the number of switches and thus reducing the switching losses. The scheme proposed here is used on an Interline Power Flow Controller (IPFC). The inverter can produce the pulses with different width and magnitude and the output almost resembles a sine wave. The proposed multilevel inverter is applied to an IPFC for protecting voltage sags, swells and momentary interruptions. The dynamic performance is analyzed and verified through MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

This work reports the numerical study of unsteady laminar boundary layer flow of viscous, electrically conducting. incompressible, fluid in a channel filled with a porous medium along with a semi-infinite vertical plate in the presence of uniform mass diffusion and transverse magnetic field. The finite element method, Galerkin is used to solve the governing equations. The flow phenomenon has been calculated with the help of flow parameters such as velocity, temperature and concentration profiles for different parameters such as. Schmidt number, Prandtl number, Magnetic field, Chemical reaction Parameter, Permeability parameter, Chemical reaction, Soret number and Grashof number. The velocity, temperature, and concentration are observed graphically. The coefficient of skin-friction, Nusselt number, and Sherwood number are calculated. [ABSTRACT FROM AUTHOR]

Smart interactions among the smart grid, aggregators and EVs can bring various benefits to all parties involved, e.g., improved reliability and safety for the smart gird, increased profits for the aggregators, as well as enhanced self benefit for EV customers. The impact of plug-in electric vehicles (PEVs) integrated into a power distribution system based on voltage-dependent control. The gasoline gate situation has many people turning to electric vehicles as a more environmentally friendly option, especially in smart community areas. The proposed PEVs model was developed as a static load model in power distribution systems under balanced load conditions. The topology of the proposed charger consists of the bidirectional ac/dc and buck–boost dc/dc converters, where it can operate in four quadrants in the active-reactive power plane with the capability of harmonic compensation. Based on the PQ theory, the active and reactive power that includes average and oscillatory components obtained, based on the demand of nonlinear/linear loads and EV battery. In this paper presents the design of a single-phase electric vehicle (EV) on-board bidirectional charger with the capability of power conditioning based on its control in charging/discharging active power based on the demand of EV battery/network or load. The proposed approach was validated and implemented in software packages like MATLAB/OPALRT or etc to integrate the fidelity of the physical simulation and the flexibility of the numerical simulations. [ABSTRACT FROM AUTHOR]

Identification of approximate model of the physical systems can be achieved by fitting the data. In this paper particle swarm optimization algorithm (PSO) is used for linear and polynomial curve fittings. Data generated from the known models and curve fitting is done by PSO using reverse engineering mechanism at the initial stage. In this process of curve fitting, two types of inertia mechanisms are used in PSO for getting better results. Later, real time financial series forecasting is considered for validating the PSO estimated regression models. Results shows the dynamic inertia weight strategy based PSO yields better fitting and avoids additional decisions on control parameters. [ABSTRACT FROM AUTHOR]

The design of induction motor for Electric Vehicle application is different from that of conventional induction motor, which is used in various drive applications. The performance parameters of an induction motor depend on various design parameters including electrical and mechanical. In this paper study of various parameters such as core axial length, stator inner diameter and rotor outer diameter is done. The effect of these parameters on induction motor characteristics is studied using analytical method. The analysis is done one two different induction motors and their performance is compared. [ABSTRACT FROM AUTHOR]

A new evolutionary algorithm called colliding bodies optimization (CBO) considered in this paper to solve optimal power flow (OPF) problem in a power system network. CBO is based on natural phenomenon of one dimensional collision between two objectives. It does not have any control parameters and simple in structure. IEEE 30-bus system with various objective functions like, minimization of total fuel cost with valve point loading effect, minimization of emission profile are considered to test the feasibility and effectiveness of the CBO algorithm. In comparison with the other existed methods presented in the literature, the proposed CBO algorithm gives better optimal solutions for single objective OPF problems. [ABSTRACT FROM AUTHOR]

The different types of human exercises particularly those recognized with development, signifies outflow of ozone depleting substances, greenhouse emissions that outcome into an Earth-wide temperature boost and environmental change. This affects nature and leads to imbalance in the environment and ecosystem. Henceforth it has turned out to be important to reduce dangerous atmospheric changes by some sustainable mitigation processes. In all the greenhouse gases, CO2 is the main compound that adds to a worldwide temperature alteration. Thus it is fundamental responsibility for every person to control the carbon outflow by understanding the concept of sustainable development. Carbon footprint estimation for an institutional and residential building was done separately for each component of structure or as a whole organization. The reason for this investigation includes distinguishing proof and examination of different emission inventories and the measure of carbon transmitted by them regarding an institutional structure and the residential building materials also assessed. Furthermore this study examines the current methodologies and approaches to estimate carbon footprint in an institutional building and residential building in Karnataka. To ascertain the status of carbon emission in the residential building materials a study was carried out in a proposed residential structure. It was concluded that the existing institutional building is carbon positive and also the amount of carbon emission by building materials used in the residential building also contribute to carbon footprint results to carbon positive. So as to lessen the emission and to convert the institutional structure and the residential building materials from carbon positive to carbon negative, general mitigation measures are recommended and by implementing the same how much carbon emissions also reduced was discussed.This research study also helps in creating awareness about the impact of amount carbon emissions happening in an institutional building due to different activities among the students, faculties and other public/Stake holders. [ABSTRACT FROM AUTHOR]

Electricity is essential for daily life of the people and also for strengthening the economy. Over the past few years, the electric power industry, in many countries, has undergone significant changes in the total installed generation capacity using conventional and non-conventional energy sources. Despite of this remarkable progress, economy is still facing an enormous need to meet the growing demand of electricity thereby increasing the competition, offering opportunities to number of generating companies, to deliver the electric power with same local service, same local quality, and same local load delivery. This rapid increase in the power generation from various emerging integrated energy sources are becoming a challenge to the existing transmission network. Considering calculation accuracy and time this paper focuses on the study of different computational approaches to continuously compute Available Transfer capability (ATC) of a load change and line outages to give accurate results so as to upgrade it in a deregulated transmission network. Different optimization techniques are briefly discussed in the review paper necessary for a large scale power bus transmission system to withstand the contingencies more efficiently. This conceptual approach unites various publications on congestion management in deregulated power system in past few decades considering it in a hybrid power market. [ABSTRACT FROM AUTHOR]

The Activity deals with an automated article allocation and implementing actual administration (pick and place) for called items application apprentice system. It synchronizes the movement of automatic arm to aces the altar affective on a agent belt. It aims in classifying the color (black, red, green, blue) and shaped altar (circular, aboveboard shaped preferable) which are advancing on the agent by acrimonious and agreement the altar in its corresponding pre- programmed location. Thereby eliminating the terrestrial plan done by human, accomplishing accurateness and acceleration in the work. The proposed arrangement makes use of avant-garde Raspberry Pi processor and as well USB camera to faculty the called altar affective on the conveyer belt. The altar are sensed application an USB camera. When the article appears abreast to its around again the arrangement captures an angel and fed as ascribe arresting the Raspberry Pi processor for added implementation. The Raspberry Pi processor checks the captured angel from the predefined abstracts abject like appearance and blush of the object. When the article detected matches with the called appearance like blush and ad measurement again it activates the automatic arm motors application interfacing circuits. The basal firmware for the Raspberry Pi is accounting in PHP/Python language. The arrangement uses DC motor for the movement of conveyer belt and servomotor for automatic arm gripper to aces the altar of corresponding blush and appearance from the anchored area at accurate direction.The Raspberry Pi is a low cost, credit-card sized computer that can be acclimated in electronics projects. It is a able little accessory that enables humans of all ages to analyze computing, and to apprentice how to affairs in languages like Scratch and Python. It's able of accomplishing aggregate you'd apprehend a desktop computer to do, from browsing the internet and arena high-definition video, to authoritative spreadsheets, word-processing, and arena games. [ABSTRACT FROM AUTHOR]