Search

Y1-xVO4: Eux-y3+: Pry3+ with x = 6 mole % and y = 0, 2, 3 ,4, 5, 6, mole % phosphors have been prepared by solid state reaction. The dopant Eu3+ concentration was optimized along with the co-dopant Pr3+ concentration in the yttrium vanadate host lattice with the help of photoluminescence (PL) spectra. The phosphors have displayed red color under UV source. Pr3+ acts as quencher and quenching effect of co-dopant Pr3+ on Red Emitting Yttrium Vanadate Phosphor Doped with Eu(III) using luminescence Studies on Y1-XVO4: Eux-y3+ : Pry3+ systems are presented in detail in this paper. The emission intensities were determined and the relative fluorescence intensities have been estimated. The richness of the red color is verified by determining the chromaticity coordinates (X, Y) from the CIE standard charts. [ABSTRACT FROM AUTHOR]

The dielectric relaxation measurements in the frequency range of 10 MHz to 30 GHz and at temperature range of 0 °C to 25 °C using a picosecond time domain reflectometry technique have been carried out over entire concentrations of binary mixtures 2-Chloroaniline with 2-methoxyethanol. The complex dielectric permittivity spectra of 2- CA with 2-ME binary mixture were fitted using Havriliak–Negami equation. The static dielectric constant and relaxation time for all concentrations were obtained using least square fit method. The principal relaxation time is small if compared to that of corresponding aniline/alcohol binary mixtures this may be due to the hydrogen bonding ether oxygen in the 2-CA/2-ME system. The results are interpreted in terms of heterogeneous interactions among the unlike molecules due to hydrogen bonding. [ABSTRACT FROM AUTHOR]

The series of Cr-Zn and Cr-Co nanoferrites bearing the general chemical composition CrxZnFe2−xO4 and CrxCoFe2−xO4 (0 ≤ x ≤ 0.5) were successfully synthesized by sol–gel method. The prepared samples were annealed at 900 °C temperature for 3 hours. The aim of the present comparative analysis was to investigate the impact of Cr3+ ion substitution on the structural properties of Zn and Co- nanoferrite systems. Various characterization techniques such as XRD, FTIR, TEM, etc. were used to investigate the structural properties of both nanoferrite samples. XRD patterns of the both ferrite samples provide information about the existence of single phase spinel structure. The average crystallite size was found to be ranging from 24–34 nm and 56-75nm in case of Cr-Zn and Cr-Co ferrite systems respectively. The analysis revealed that with the increase in Cr- concentration (x), the average crystallite size decreased gradually in Cr- Zn ferrite system but decreased non-linearly in Cr-Co ferrite system. FTIR spectra show that the bands υ1 and υ2 are found to shift towards the higher frequency side with substitution of Cr3+ ions. TEM reports demonstrated that the particles with narrow size distribution were procured. The analysis revealed that the amount of Cr concentration (x) significantly influenced the crystal morphology and the structural properties of both Cr-Zn and Cr-Co nanoferrites systems. [ABSTRACT FROM AUTHOR]

Driving while either intoxicated or drunk is dangerous and drivers with high blood alcohol content or concentration (BAC) are at greatly increased risk of car accidents, highway injuries and vehicular deaths. Although the proportion of crashes that are alcohol-related has dropped dramatically in recent decades, there are still far too many such preventable accidents. Unfortunately, despite great progress, alcohol-impaired driving remains a serious national problem that tragically affects many victims annually. At present drunken drivers have increased enormously and so is the deaths due to drunken drivers. In this paper an alcohol detection system is designed and implemented. Apart from sensing the alcohol, the ignition of the fuel is regulated by a sensor circuit. The sensor circuit is used to detect whether alcohol was consumed by the driver recently. This design also consists of sensor which is used to check whether alcohol is consumed while driving. A prototype is also designed which detects the amount of alcohol taken by the person. When the amount of the alcohol is reached to a threshold limit (Dangerous/maximum) it automatically turns off the combustion engine of the vehicle with buzzer indication and simultaneously with a LED indication. [ABSTRACT FROM AUTHOR]

Y1-XVO4: Eux3+ (x = 3 mole % to 8 mole%) phosphors have been prepared by solid state reaction. The dopant Eu3+ concentration was optimized in the Yttrium Vanadate host lattice with the help of Photoluminescence (PL) spectra. These phosphors have displayed bright red color under UV source. The emission intensities were determined and the relative fluorescence intensities have been estimated. The richness of the red color has been verified by determining their chromaticity coordinates (X, Y) from the CIE standard charts also. The size effect on the emission is discussed. XRD of the samples prepared are used for the conformity of the host and dopant. The prominent ratio of intensities of 5D0 → 7F2 / 5D0 → 7F1 reported earlier in literature is 3.1 while in the present case it is 3.66 indicating a better processes of synthesis of the YVO4:Eu. [ABSTRACT FROM AUTHOR]

Thermoluminescence (TL) characteristics of X-ray irradiated pure and doped with four different rare earth ions (viz., Pr3+, Nd3+, Sm3+ and Eu3+) Li2O-Cao-B2O3 glasses have been studied in the temperature range 303-573K; the pure glass has exhibited single TL peak at 424K. When this glass is doped with different rare earth ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Eu3+ doped glasses. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen’s formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that europium doped calcium borate glass has a potential to be considered as the thermoluminescence dosimeter. [ABSTRACT FROM AUTHOR]

Glass samples with composition (35- X) B2O3 - (40 +X) PbO - 25 TiO2 (where X= 0, 2.5,5, 7.5 and 10 mol %) were prepared using conventional quenching technique. It was observed that as PbO content increases the values glass transition temperature (Tg) and crystallization temperature (Tc) decreases. The replacement of boron by a bigger Pb ion expands the network there by reducing the glass transition temperature (Tg). These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density(ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix. As the content of glass former (B2O3) is reduced, the PbTiO3 crystals precipitated in glass matrix are observed to increase. The dielectric constant values of glass ceramic samples are higher than those of corresponding glass samples. [ABSTRACT FROM AUTHOR]

Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X =0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. Transition temperature (Tg), crystallization temperature (Tc), density and Coefficient of Thermal Expansion (CTE) of glass and glass ceramic samples measured. Tg and Tc observed to decrease with increase in the content of TiO2. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass–ceramics. The dielectric constant of glass ceramic samples is higher than those of corresponding glasses. Maxwell’s dielectric mixture formula was used to correlate the theoretically predicted values of dielectric constant with experimentally observed values. [ABSTRACT FROM AUTHOR]

Smart materials are playing a major role in today's technology because of its inbuilt characteristics. This paper deals with one of such smart material called "Magnet rheological fluid (MRF) ". This fluid is chosen for the development of fixture because of its response to magnetic field. There is a remarkable development in every field of engineering & technology which is the main cause of designing new equipment, vehicles & machines which contains few complicated parts. These complicated parts require specially designed fixtures to hold it during machining operations. The design & developing of these fixtures is a time & money consuming process. The development of multi-functional fixtures will save both time & money. Considering this necessity as a factor the development of Multi functional fixtures using magnet rheological fluid is poposed. [ABSTRACT FROM AUTHOR]

Glass samples with composition (50 - X) PbO - XCaO - 25 TiO2 - 25 B2O3 (where = 0, .5, 10 and 15 mol %) were prepared using conventional quenching technique. It was observed that with the addition of alkaline earth oxides to lead borate glass containing TiO2 alters the network (conversion of BO3 to BO4) increasing the rigidity of the glass which enhances the Tg. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass-ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase and Ca3Ti2O7 as minor crystalline phase. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. [ABSTRACT FROM AUTHOR]

The polycrystalline material Sr(Bi3.9-xNdxLa0.1)(Ti3.975Zr0.025)O15 with variation of neodymium content from 2.5 to 10 wt% was prepared by solid state method. XRD analysis indicated the formation of a single- phase orthorhombic structure. SEM analysis revealed the formation of plate like structure. It was also observed that with increase in the content of Nd, the values of Curie temperature (Tc) and dielectric constant (ε) were increased and the tolerance factor (t) decreased. It was found that the remnant polarization, piezoelectric charge and electromechanical coupling coefficients were increased up to certain extent of Nd doping and further increase of Nd content decreased. [ABSTRACT FROM AUTHOR]

Polycrystalline SrBi4Ti3.95Zr0.05O15 (SBZT) ceramic was prepared by solid-state double sintering method. It was characterized by X-Ray Diffraction (XRD) and Scanning Electron Micrograph (SEM). With the increased addition of ZrO2, the electrical properties as dielectric, ferroelectric and piezoelectric were studied. From XRD, single-phase formation with orthorhombic structure was identified by the increase of ZrO2. The remnant polarization (Pr) and dielectric constant was found to be increased with the increase of ZrO2. With the increase of ZrO2, Curie temperature (Tc) was found to be decreased. The planar electromechanical coupling coefficient (Kp = 0.57) and Piezoelectric coefficient (d33 = 18 pC/N) was found to be increased with the increase of ZrO2. [ABSTRACT FROM AUTHOR]

Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X = 0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase. The SEM results show rounded crystallite of lead titanate. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. The extended heat treatment of glass ceramic samples at 593K for 10 h exhibited saturated hysteresis loops with higher values of remnant polarization. [ABSTRACT FROM AUTHOR]

Among all transition metal dichalcogenides (TMDs), MoS2 shows very unique conducting and optoelectronic properties, which makes it the most suitable material for fabricating real-time sensors and atomically thin transistors. By chemical modifications, the MoS2 can be made more useful in the field of various gas sensors, biosensors, and optoelectronic devices. In this study we present a novel facile method to grow 2-D MoS2 thin films by electrochemical deposition technique. We have successfully grown MoS2 thin films on ITO substrates through functionalization of MoS2 nano-flakes in the presence of monochloroacetic acid (MCA). The functionalization of trigonal prismatic MoS2 flakes with carboxyl group was achieved through sonication of MoS2 solution in DI water in the presence of MCA and KOH. Due to weak van der Walls force between the sulphur-sulphur layers of MoS2 flake, ultrasonic vibrations can easily intercalate the MoS2 flakes, creating sulphur vacancies at the two outer side surfaces and further saturated by Cl atoms of the MCA, forming MoS2-COOH composites. The as grown composites were then driven through linear sweep voltammetry on an ITO glass plate to form MoS2 thin film by controlling the sweeping cycles. The growth of the thin film was confirmed by the cyclic voltammetric current responses, which show the corresponding change in oxidation peak currents after the deposition of MoS2 thin film on the ITO substrates. It was further observed that the charge transfer decreases with the increase in thickness of the thin film as expected from the thick MoS2 semiconductor. These 2-D MoS2 can be of immense use in designing new type of real-time semiconducting biosensors, gas and electrochemical sensors, and atomically thin 2-D transistors. [ABSTRACT FROM AUTHOR]

In this work, nickel oxide thin films have been successfully deposited with a simple and low-cost spin coating method and annealed at 250⁰C. The structural and optical characterization of the NiO thin films was carried out using XRD, SEM, EDAX and UV-visible spectrophotometer. XRD pattern shows that all the prepared samples are in cubic structure and well-matched with JCPDS. From SEM, it is seen that all the films are uniform. From the transmittance spectra, the prepared samples are highly transparent, and the optical energy band gap was calculated from absorption spectra. These prepared samples were tested using static gas sensing set up to detect different reducing analyte gases including ammonia towards various ppm at room temperature. Ammonia is found to be good selective and highly sensitive. Response time and recovery time of the fabricated sensor were calculated and reported. [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 the present work, a novel polyaniline cerium vanadate nanocomposite was facilely prepared by in-situ polymerized sol-gel process. X-ray diffraction (XRD) pattern revealed the crystal planes and size of the synthesized nanocomposite. The morphological shape and the crystalline nature of the nanocomposite were examined by field emission scanning electron microscopy (FESEM). Fourier transform infrared spectroscopy (FT-IR) confirmed the conceivable stretching frequency on the surface of nanocomposite. Polyaniline cerium vanadate nanocomposite was used as a solid phase adsorbent for removing methylene blue (MB) from aqueous media. Besides, these nanocomposites evinced antimicrobial activity against E.coli and Staphylococcus aureus. The studies describing the synthesis of polyaniline cerium vanadate by simple in-situ polymerised sol-gel method followed by the investigation of adsorption and antibacterial activities may be useful for the research activities to open a new horizon in the field of nanotechnology. [ABSTRACT FROM AUTHOR]

Glass samples with composition (35- X) B2O3 − (40 +X) PbO - 25 TiO2 (where X = 0, 2.5, 5, 7.5 and 10 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. The density (ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix. [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]

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]

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]

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]

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]

In gentle of the current situation of populated areas, some modern towns in India and some countries women protection is the one of the main issue. In this national wide of intelligent and smart electronic devices are required for a simple and rate-ground-breaking security machine that encourages the sufferers at some phase in unexpected dangers. This assignment covers elucidating records about the configuration and usage of model for a computerized gadget which has the ability to highlight an assurance situated on inside the coming years. The equipment incorporates an exchange, LPC2148 micro controller, ESP2866 Wi-Fi module, GPS module, bell, touch sensor. The principle taking walks of women venture is that at whatever point a lady detects danger, she should simply press the push button switch of the device. When the switch is enabled, it find out the spot of the in convenience women utilizing GPS and transmit this locale the utilization of GSM technology and Wi-Fi (remote constancy), to a web database in the police station control. In this project utilizing electronic controlled surprise for simultaneously as women in risk for security. The principal concept of this equipment is that very smart and cleans to hold. The utilization of ultra-present day segments ensures precision and makes it dependable. [ABSTRACT FROM AUTHOR]

The objective of the current work is to estimate the maximum resultant displacement and energy absorption capacity of fascia and body in white structure during crash. Any change in automobile design leads to decrement of passenger's compartment area. Therefore, another option available is to change the materials in automobile which can minimize the damages in accidents. The details of the Fascia and body in white structure are taken from Honda Accord Model. The crash tests are performed on fascia considering the Dual Phase 600 Steel, TI6AL4V alloy and Acrylonitrile Butadiene Styrene (ABS) Plastic materials. The fascia crash test is performed as per United States New Car Assessment Program and Roof crush test is performed as per federal motor vehicle standards 216. Deformation and energy absorption capacity during crash have been analyzed by using finite element solver LS-DYNA. The results shows that, the energy absorption capacity of Dual Phase 600 Steel is greater than that of TI6AL4V alloy and Acrylonitrile Butadiene Styrene (ABS) Plastic during the fascia crash test. In case of roof crush test, maximum resultant displacement of Dual Phase 600 steel is less compared to TI6AL4V Alloy. This analysis helps in selection of material which can minimizes the damage during vehicle accidents. [ABSTRACT FROM AUTHOR]

Nowadays, the research is being devoted to the development of rapid and precise maximum power point tracking for various photovoltaic applications. However the constraints imposed by size, cost, efficiency, and tracking performances essentially limit the application of conventional MPPT techniques and their analysis methodologies. This study gives us a complete picture of doping materials for Maximum power extraction from the solar cell (photovoltaic cell). As it is known that pure crystalline silicon atom is a poor conductor of electricity because none of its electrons are free to move about, unlike the electrons in more optimum conductors like copper. To overcome this, the silicon in a solar cell has impurities added – which are other atoms mixed in the silicon atoms. In general definition impurities are something undesirable, but this is not the case with the solar cell, which wouldn't work without them. The process of adding impurities is called doping, and when doped with phosphorous, the resulting silicon is called N-type because of the prevalence of free electrons. N-type doped silicon is a much better conductor than pure silicon. The other part of a typical solar cell is doped with the element boron, which has only three electrons in its outer shell instead of four, to become P-type silicon. Instead of having free electrons, P-type ("p" for positive) has free openings and carries the opposite (positive) charge. To improve the efficiency of the solar cell the use of processing techniques has to be found and implemented other than the processing of silicon and boron as all the manufacturers use this technique more widely. In general a mono module rated at 180W with an area of 1.28m2 may be 14.1% efficient while a poly module rated at 200W with an area of 1.47m2 may be 13.6% efficient. So the efficiency is only a measure of module output based on module area – the higher the efficiency the more power will be produced from the same size module or on the other way, the same output with fewer modules. This could be very important where available roof space is an issue. Energy is Wh, not just W so it is needed to consider weather factors such as strength of the sunlight, the amount of cloud cover and the ambient temperature. [ABSTRACT FROM AUTHOR]

This paper aims to design SOFC and diesel generator based hybrid system that will cater domestic as well as irrigation need in a remote located village. Modeling and simulations are carried out in MATLAB Simulink platform. Load behaviour is analyzed by modeling of solid-oxide fuel cell as distributed generator power system. The output of the system with respect to step changes in load demand is obtained along with the analysis of the simulated results. Solid oxide fuel cells operate at temperatures near l000°C. Modeling of SOFC is done by using Nernst equation. In that the output power of the fuel cell can be controlled by controlling the flow rate of the fuels used in the process. The fuel cell source is integrated with diesel generator and battery hybrid energy system. [ABSTRACT FROM AUTHOR]

MEMS based actuator and scanning mirrors are device that steers and reflects incident light by angular rotation of the mirror itself. For single axis scanning, the mirror itself provides the required angular rotation, while most of the biaxial scanning micro mirrors have a gimbal configuration. Electrostatic actuation is commonly being used because of ease of fabrication and work on the principle of electrostatic forces between pairs of movable and fixed electrodes. Parallel plate type tip-tilt/scanning mirror is commonly being used for smaller mirror dimensions (up to 2mm). For larger mirror diameter (>2mm), the desired scan angle leads to large gap between the electrodes, which increases the driving voltage drastically and leads to bulky driver controller. Alignment between fingers is essential to avoid lateral instability causing an in-plane rotational pull-in during an actuation. To reduce the driving voltage, the straight torsion springs which connect the mirror to the gimbal are replaced by comb structures. It finds applications in optical MEMS (OMEMS) [1, 2], digital light projector, optical switch, adaptive optics, communications, signal sensing, and confocal microscopes. In this paper, design, simulation of electrostatic actuation based parallel plate comb type two axis tilt scanning micro mirror is described. The effect of comb structure on pull-down voltage and resonant frequency is studied. [ABSTRACT FROM AUTHOR]

Here we report numerical simulation results obtained by performing photonic band structure calculations for a 2D periodic array of dielectric cylinders, having square symmetry with a lattice constant of 600nm. We have performed electromagnetic calculations using finite element method by employing COMSOL Multiphysics software. The band structure of the infinite crystal is calculated using plane wave method using MIT Photonic Band gap Package software. The calculated reflectance spectra showed three photonic bands spanning over visible and Infra-red regions a for refractive index contrast of 2.98. In order to study the property of a resonator, a point defect is introduced by replacing the dielectric cylinder with an air-cylinder. A sharp dip within the band gap of the reflectance spectra is observed and is attributed to the localized mode associated with the defect. Q-factor associated with the localized mode is calculated. The effect of refractive index of the defect on the localized mode frequency have been investigated and results are reported here. [ABSTRACT FROM AUTHOR]

Relaxation property is always matter of interest for the frequency dependent study of the ferroelectric materials. The Nyquist plot of the impedance data provides the information about the relaxation phenomena. Often, in solids, instead of a single relaxation time a distribution of the relaxation times is found, which arises from the different mechanisms. Usually, the relaxation times is varied by substitution and its influence is studied on the basis of the compositional effects, but the impact of the size of the substituent is rarely analyzed. Fundamentally, the substituted cations modulatethe crystal structure of the parent material, which attunes the relaxation phenomenon. In the current study, the Rb substituted lead free Na0.5Bi0.5TiO3 (perovskite structure, ABO3 type) is chosen as its A-site is compositionally disorder due to the presence of the different cations with dissimilar radii. The samples are prepared through the solid state sintering method. The imaginary part of the complex impedance (Z) vs its real part (Z) are plotted for all samples to verify the response of the grain and grain boundaries. At the higher temperatures (≥500°C) single semi-circular arcs are formed by the materials for all the compositions. Interestingly, two semi-circular arcs are observed for the material for the higher cation-site disordered system at lower temperature (below 300°C). The second circle is associated with the different relaxation time of the dipolar entity, which may be generated due to the substitution of the Rb1+. This observation prove that the cation size mismatch creates the variation in the relaxation times at the lower temperatures. The cation size mismatch also modulates the contribution of the grain boundary to the impedance property. The real part of impedance of the 4 mol %, substituted Na0.5Bi0.5TiO3 is enhanced than parent Na0.5Bi0.5TiO3, which fortifies its performance as a capacitor and energy storage device. [ABSTRACT FROM AUTHOR]

A straightforward and precise HPLC method for the Quantitative determination of (E)-3-(3-(dimethylamino) propyl)-3-(3-(4-hydroxy-3methoxyphenyl) acryloyl) dihydrofuran-2(3H)-one tartarate (a potential spermicide) was developed and validated by following the rules of ICH guidelines. HPLC separation was achieved on C-18 column (merk, 250mm, 4.6mm, 5 µm) using a mobile phase of composition 85:15 (v/v) (acetonitrile and 0.1% acetic acid in water) at a flow rate of 1 mL/min. Photo diode array detector was used for monitoring eluents at 240 nm. LOD (limit of detection) and LLOQ (lower limit of quantification) were established to be 0.69 µg/mL and 1.95 µg/mL. The method was validated according to the ICH guidelines for linearity, LOD, LOQ (limit of quantification), recovery, precision and accuracy. [ABSTRACT FROM AUTHOR]

The composition of Anthracene and Lead Titanate is prepared using Solid State reaction method. Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Lead (II) titanate is an inorganic compound with the chemical formula PbTiO3. It is the lead salt of titanic acid. Lead (II) Titanate is a yellow powder that is insoluble in water. At high temperatures, lead Titanate adopts a cubic perovskite structure. The samples of Anthracene Lead Titanate composites of suitable mixture ratio are prepared using Solid state reaction method. The Crystal structure of the calcined powders and also sintered ceramics were analyzed using XRD (X-ray diffraction). The microstructure of the sintered ceramics has been investigated by using SEM (Scanning Electron Microscopy).The dielectric constants were calculated for different mixture ratios and at different temperatures are reported in this paper. It was observed that an increase in temperature there is a change in the dielectric constants has also been reported in this paper. It observed that the dielectric constant increasing with temperature increases. [ABSTRACT FROM AUTHOR]

This paper studies the effects of viscous dissipation, chemical reaction and heat generation/absorption on unsteady MHD Casson fluid flow over an exponentially accelerated vertical plate embedded in a porous medium with ramped wall temperature and ramped surface concentration. By introducing the similarity variables, the dimensional governing equations are converted to non-dimensional form and solved numerically by using the Galerkin Finite Element Method and expressions for velocity, temperature and concentration profiles are obtained. The change of velocity, temperature and concentration profiles effected by the parameters such as Prandtl number(Pr), Casson parameter (γ), permeability parameter (k), Schmidt number (Sc), Grashof number (Gr, Gm), chemical reaction parameter R′, heat generation/absorption (H), Eckert number (Ec). The obtained results are presented graphically and discussed quantitatively. [ABSTRACT FROM AUTHOR]

This paper addresses free convection in cavity filled with ethylene glycol(EG) nanofluid containing Fe3O4 in the presence of radiation. Galerkin's method of finite elements is employed to solve the governing differential equations. Numerical results are computed for certain pertinent parameters: Rayleigh number (10-2500), radiation parameter (1-10) and nanofluid volume fraction (0-0.3), and presented in the graphical form. The results reveal that flow intensity and heat transfer rate in EG-Fe3O4 nanofluid are increasing functions of Rayleigh number and radiation. It is noted that high Rayleigh number and radiation are needed to affect flow intensity. [ABSTRACT FROM AUTHOR]

In dye-sensitized solar cells, the binder used in the fabrication of the semiconductor photo-anode layer plays a significant role in the surface morphology of the anode film, which has impact on the overall performance of the DSSCs. In this work, two synthetic polymers viz., (poly (vinyl alcohol) (PVA), poly (vinylpyrrolidone) (PVP)) and their blends (1:1, 1:3, 3:1) are used as a binder and investigated their effect on the efficiency of the DSSCs. The DSSC devices are fabricated using commercial TiO2 nanopowder as photoanode anode, N719 dye, Idolyte HI-30 as electrolyte and Plastisol T as counter electrode. Among the various DSSCs fabricated, the sample prepared with pure PVP as binder shows the highest power conversion efficiency of 1.87%, short-circuit photocurrent density and open-circuit voltage of 10.14 mA/cm2 and 0.56 V, respectively. [ABSTRACT FROM AUTHOR]

The paper deals with a theoretical investigation of the peristaltic transport of a couple-stress fluid with heat and mass transfer effects. The velocity, pressure drop, time averaged flux, frictional force, mechanical efficiency, temperature profile, nanoparticle phenomena, heat transfer coefficient and mass transfer coefficient of the fluid are investigated, when the Reynold's number is small and wave length is large by using appropriate analytical methods. Effects of different physical parameters like couple-stress fluid parameters, Brownian motion parameter, thermophoresis parameter, local temperature Grashof number as well as local nanoparticle Grashof number on pressure drop characteristics, frictional force, mechanical efficiency, heat transfer coefficient, mass transfer coefficient, steam line patterns and velocity profiles of the fluid are studied. The expressions for velocity, temperature profile, nanoparticle phenomenon, heat transfer coefficient and mass transfer coefficients are sketched through graphs in two as well as in three dimensional views. The streamlines are drawn to discuss trapping phenomenon for some physical quantities. [ABSTRACT FROM AUTHOR]

In this present investigation, unsteady boundary layer flow of MHD free convection heat and mass transfer flow of a viscous, incompressible and electrically conducting fluid over an impulsively started infinite vertical plate in presence of thermal radiation and Jeffrey fluid. For this study, the magnetic Reynolds number is considered to be so small that the induced magnetic field can be neglected. The fundamental equations are solved for numerical solutions using Element Free Galerkin Method. The numerical values of with the help of some engineering parameters on fluid velocity, fluid temperature and fluid concentration are displayed graphically. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis of MWCNTs incorporated TiO2 nanotubes (TNTs) to make a hybrid nanocomposite of TNT - MWCNTs. The as-synthesized TNT - MWCNTs composite structural, optical, elemental analysis was characterized by using different techniques such as X-ray diffraction (XRD), UV-visible spectroscopy, and energy dispersive spectroscopy (EDAX), elemental mapping. The morphology and formation of TiO2 - MWCNTs composite nanotubes was confirmed from electron microscopy techniques viz., field emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HR-TEM). The effect of concentration of MWCNTs in TNT-MWCNT photoanode on the performance for dye-sensitized solar cells (DSSCs) was investigated. The performance of DSSCs were evaluated by measuring photocurrent voltage (I-V) characteristics and electrochemical impedance spectroscopic (EIS) and found that the power conversion efficiency of DSSC depends on the concentration MWCNT in the photoanode. DSSC fabricated using 6 wt % of MWCNT with respect to TiO2 containing nanocomposite as photoanode has shown high power conversion efficiency (PCE) of 1.99%. [ABSTRACT FROM AUTHOR]

Aqueous suspensions of thermo responsive poly (N-isopropyl acrylamide) (PNIPAM) microgel particles exhibit volume phase transition (VPT) around 34°C. PNIPAM microgel spheres are known to be core-shell type having a dense core and a fuzzy shell of dangling polymer chains. Recently (Joshi and Tata Colloid and Polymer Sci. 295, 1671 (2017)) it was shown that under dense conditions i.e. volume fraction, ϕ > 0.64 PNIPAM microgel suspensions exhibit glassy state and undergo two step yielding upon application of shear. Two-step yielding is observed only in colloidal systems with attractive interactions. Observation of two-step yielding is unusual in a PNIPAM microgel glasses as PNIPAM microgel particles are known to be repulsive soft-spheres. Tata and Joshi argued that two-step yielding in dense PNIPAM microgel occur due to the breaking of entanglements of dangling polymer chains between shells of microgels and breaking of the near neighbor cages, respectively. Motivated by these studies and to verify entanglements have really a role in yielding, we synthesized two types of PNIPAM microgel spheres one having only a homogeneous core (referred to as HC) and the other with usual core-shell type (referred to as CS). We report here the results obtained by performing non-linear rheological measurements on dense suspensions of HC and CS type PNIPAM microgel spheres. We observed two steps yielding in dense CS PNIPAM microgels suspension in its glassy state, but not with HC-PNIPAM spheres. Apart from the above observation, we report here the detailed non-linear rheological study in dense colloidal glasses of HC and CS type PNIPAM microgel particles. [ABSTRACT FROM AUTHOR]

The aim of this research work is to found the numerical solutions of magneto-hydro-dynamic electrically conducting, viscous fluid flow towards a vertically inclined plate in presence of heat and mass transfer, chemical reaction effects. The basic governing equations such as momentum, energy, and concentration are solved using an efficient finite element method which is more accurate than other numerical methods. For this study, there are several engineering flow parameters effects on velocity, temperature and concentration fields are discussed through graphs. [ABSTRACT FROM AUTHOR]

In this paper the effect of magnesium (Mg) substitution in lithium (Li) site of spinel lithium titanate (Li4Ti5O12, LTO) based materials for anodes of Li-ion batteries (LIBs) is extensively studied. The anode materials based on the formula Li4-xMgxTi5O12(x=0 and 0.2) are synthesized using conventional ceramic route at 850° C for 16h. Their phase formation processes, crystal structures, morphology, elemental analysis, cation distribution and electrical properties were studied using XRD, SEM, EDX, FT-IR and CIS characterization techniques. The XRD studies revealed the exact structure of the material which belonged to cubic spinel structure as part of the space group Fd-3m. The morphological characteristics related to phase and grain size allocation were found using SEM and the grain size was found to be in the range 0.9-1.1 µm. The FT-IR results revealed the oxide lattice structure built of MO6 (M= Li, Mg and Ti) as tetrahedra and octahedra. The electrical impedance studies showed the material (Li3.8Mg0.2Ti5O12) to exhibit excellent conductivity which was found to be 3.8×10−5 S/cm at ambient temperature for frequency ranging from 20 Hz to 1MHz. [ABSTRACT FROM AUTHOR]