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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]

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]

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]

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]

Molecular adsorption of hydrogen in lithium decorated smallest fullerene (C20Li2) has been carried out within the framework of density functional theory (DFT) at B3LYP/6311+G(d,p) level. Hydrogen molecules were added sequentially till maximum number of hydrogen molecules could be accommodate by the C20Li2. The kinetic stabilities of the hydrogenated clusters were confirmed through global reactivity descriptors and electronic band gaps. It was observed that the C20Li2 clusters could hold maximum up to eight hydrogen molecule with average adsorption energy in the range 0.11 - 0.06 eV/H2 resulting in gravimetric density of 5.98 wt% which was in accordance with the target set by US Department of Energy (US-DOE) for optimal hydrogen adsorption. The average adsorption energy value and the distance between Li atom and hydrogen molecules indicated the process to be physisorption type. Topological analysis using Bader's quantum theory of atoms in molecules (QTAIM) concluded that the interaction between H2 and Li atom to be closed shell type with ρ < 0.20 a.u with positive ∇2ρ corresponding to ionic or van der Walls bonds. [ABSTRACT FROM AUTHOR]

Ternary transition metal sulfides are propitious electrode materials caused by low electronegativity, high conductivity and higher electrochemical activity in comparison to transition metal oxides and single metal sulfides. In this work, Zinc Cobalt Sulfide (ZCS)nanosheets have been successfully prepared through a simple, cost-effective hydrothermal method and characterized by X- Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X- Ray Analysis (EDX), Transmission Electron Microscope (TEM), and X-Ray Photoelectron Spectroscopy (XPS). The supercapacitor performance of ZCS nanomaterial electrodes was done by electrochemical measurements and ZCS nanosheets revealed a clear enhancement in specific capacity and cycling stability. Electrochemical impedance spectroscopy showed a much lower charge transfer resistance of the samples. These results proved that the ZCS nanosheets may be utilized as capable electrode materials for next generation energy storage devices. [ABSTRACT FROM AUTHOR]

In this article, we report advancement in structural, morphological and dielectric studies of PVA encapsulated titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles. PVA/(x)TiO2(15-x)ZnO nanocomposites are prepared using solvent casting ex-situ technique for x= 0wt%, 1wt%, 5wt%, 7.5wt%, 10wt%, 14wt% and 15wt% filling concentrations. FTIR spectroscopy reveals the formulation of complexes between the PVA main chain and nano fillers is due to inter/intra molecular hydrogen bonding. The AFM picture shows the uniform grain structure for pure PVA and changes in surface morphology for prepared PVA nanocomposites. The morphological and homogeneous distribution of nano fillers in PVA nanocomposites was observed using SEM and EDAX. AC conductivity studies spectacles that the conductivity increases for different filling concentrations with increase in frequency. The frequency dependent dielectric constants with different filling concentrations are recorded. [ABSTRACT FROM AUTHOR]

As brass materials are having high strength and high resistance towards corrosion, along with high thermal and electrical conductivity, these were the reasons for their wide usage in the industry as engineering materials. Although they have good appearance, they can also be shaped easily. Anyhow, fusion welding of brass is a difficult task, as during the process of fusion welding zinc evaporation has been a major concern which these alloys which affects its chemical and physical properties. Many researchers have been working for the new methods as problems due to fusion welding are not getting solved in case of brass. In this scenario Friction stir welding is one of the novel methods to solve these problems. Then, experimental investigations were needed in this domain. Although decent research works have been reported on FSW of Aluminum, copper and their alloys, but constrained work has been done in case of brass. This research aims to determine the optimum parameters for FSW of brass and corrosion test, tensile test, environmental tests, surface morphology and surface metallurgy results has been examined on the obtained weld joints. [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]

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]

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 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]

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]

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]

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]

Li2O-B2O3 glasses were synthesized doping with TiO2 and co-doping with TiO2 as well as ZnO nanoparticles through the melt-quenching process. LB1, LBT2 and LBTZ3 were the labeling of the samples. The X-ray analysis of these glass samples have shown two amorphous halos at small values of 2θ (≈ 22o and 45o), which were due to the short-range periodicity of the glass network as a result of non-bridging oxygens (NBOs). The prominent bands exhibited in FTIR spectra were due to trigonal (BO3) and tetrahedral (BO4) structural units and as well due to bending vibrations of B–O–B linkages. The absorption bands observed in the spectra were attributed to stretching vibration modes of O-H bonds present in the moisture in the glass samples. The rigidity of the samples follows order: LBT2 > LBTZ3 > LB1. The ESR spectra of the sample LBTZ3 has shown a spectral line centered at about g≈1.94. The addition of ZnO nanoparticles into the glass matrix leads to convert the non-magnetic glass sample into a magnetic glass material; because some of Ti4+ ions may be converted as Ti3+ ions in the melt-quenching process. Thus, we expect that these materials can find potential applications such as solid state electrolytes, humidity sensors and magnetic sensors etc. [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]

Samples of the type Cu1-X Cox Fe2O4 with x = 0.2, 0.4, 0.6 were prepared by DSCM (Double Sintering Ceramic Method). A.C conductivity measurements were carried out at different frequencies up to 50 Hz -05 MHz at various temperatures from room temperature to about 673K. The A.C conductivity was measured by four probe method using Wanyekerr electronics high precession imp-dense analyzer (6500) model. The results showed that the conductivity increases with both temperature and frequency. At high temperatures the conductivity becomes frequency independent. So we conclude that the conductivity in these ferrites consists of two kinds of conduction mechanisms. [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]

Herein, we investigated the nonlinear optical (NLO) response and optical absorption spectra of the carbon doped boron cluster (CB10) along with its isomer within the principles of density functional theory (DFT) and time-dependent density functional theory (TDDFT) respectively. Optical absorption spectra of carbon doped boron cluster were computed using exchange-correlation functional such as; CAM-B3LYP and wb97xD employing 6-311++(2d,2p) basis set. The calculated absorption spectra of the studied compounds mostly fall in the ultraviolet (UV) and visible region in the range 246 nm-409 nm (B10), 231 nm-652 nm (B10C-I), and 236nm - 491 nm (B10C-II) for both the methods respectively. The most prominent peaks of the studied clusters were observed at around 312 nm, 233 nm and 266 nm respectively. In addition, we noticed a very minimal peak in the near visible region in the range between 609 nm–640 nm for all the studied clusters. However, we observed a red shift of around 82 nm for B10C-II cluster. Static polarizability and hyperpolarizabilities were also computed. It has been observed that the carbon doping enhance the NLO responses by narrowing its HOMO-LUMO gaps whereas reverse observation was found in case of its isomer computed. The results might open new perspectives for further development of designing novel promising electro-optical boron-based nanomaterial. [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]

The polymer blend composites of PANI with PVDF/KDP have been synthesized by polymerization method. The different polymer blend of PANI with PVDF/KDP composites are obtained by adding 10, 20, 30, 40 and 50 wt% of KDP were added with PVDF of 1N concentration during PANI synthesis to get the polymer blend of PANI with PVDF/KDP composites. The synthesized samples of PANI and polymer blend of PANI with PVDF/KDP composites polymer were characterized by using X-Ray diffraction (XRD). The dielectric properties such as dielectric constant, dielectric loss and AC conductivity for the composites of polymer blend of PANI with PVDF/KDP composites at different weight percentages are studied as a function of frequency in the range 5 Hz–35 MHz at room temperature. It is found that the dielectric permittivity decreased exponentially at lower frequency region up to 180 Hz and then the dielectric permittivity remains constant at higher frequency region as the frequency increased. It is also observed that the dielectric permittivity decreased as the weight percentages of KDP increases in PVDF with PANI. AC conductivity increased for PANI, polymer blend of PANI with PVDF/KDP composites at 10, 20, 30 and but for 40 and 50 wt% it is decreased. [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, we report fabrication of high quality visible light photo-detector based on nano-crystalline cadmium sulfide (CdS) thin film deposited on glass substrate using spray pyrolysis technique. Structural, morphological and chemical analysis of the film confirms uniform coating of sulfur deficient nano-crystalline CdS thin film with∼30 nm crystallites. Finger electrodes were made on the film using Ag paste. Photo-detection property of nano-crystalline CdS thin films was tested under visible light illumination and the response of incident light in terms of photo-current was monitored when exposed at various light intensities ranging from 5 to 320 mW/cm2. The fabricated device showed highly sensitive and repeatable photo-detection at 10 V for low power 5 mW/cm2 light. Time response measurements at different wavelength show ultra-fast response (0.67 ms) and decay (0.86 ms) time and high photo sensitivity at low bias voltage. [ABSTRACT FROM AUTHOR]

In this paper, we report an extremely low cost and highly efficient method for fabrication of visible light photo-detector using nano-crystalline lead sulfide (PbS) thin film. The film was fabricated on 300 GSM paper via spray pyrolysis technique at 100 °C. Structural and morphological analysis of the film confirms the nano-crystalline nature of PbS with size ∼ 50 nm and uniform coating of PbS on paper. Photo-detector devices are prepared by drawing contacts using 4B pencil on the film by keeping a gap of 1 mm between electrodes. Photo-detection property of a nano-crystalline PbS thin film under visible light illumination show linear I-V suggesting low resistive contact between graphite electrode and PbS film. The photo-sensitivity measurements reveal excellent sensitivity of ∼103 at 20 V. For this graphite/nano- PbS/paper photo-detector, the best rise and decay time is observed to be 7 and 16 ms, respectively. This simple and low cost fabrication method results in highly stable and sensitive photo-detectors device, which have fast response and decay time. [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]

The electrical properties and transport mechanisms ofNi/PVA/n-Si MIS type SBDs was investigated using I-V measurements which were performed at room temperature. The fabricated MIS SBD exhibited good rectification ratio with low leakage current when compared to Ni/n-Si MS SBD. The evaluated SBH of MIS type SBDs using PVA as an interfacial layer was found to be 0.80 eV (I-V), 0.88 eV (Cheung), 0.81 eV (Norde) improved when compared to MS structure with 0.70 eV (I-V), 0.74eV (Cheung) and 0.72eV (Norde). The ideality factor (n) values were calculated using thermionic emission (TE) theory and were found to be 1.09 for the MS and 1.35 for the MIS SBDs. The RS, 'n' values were extracted for the MIS and MS SBDs using Cheung functions and were calculated as 171 Ω, 1.24 and 3345 Ω, 1.43 respectively. The series resistance (RS) values were also extracted from H(I) versus I plot and were found to be 459 Ω for MIS SBD and 15,669 Ω for the MS SBD. Furthermore, the surface potential versus forward voltage plot of the MIS SBDs yielded a SBH of 0.77 eV which is higher than 0.68 eV achieved for MS SBD. It can be concluded that the deliberately deposited PVA as an insulating layer at the Ni/n-Si interface remarkably varied the electrical properties of the fabricated Ni/PVA/n-Si MIS SBDs. [ABSTRACT FROM AUTHOR]

A series of composites of TiO2/activated carbon has been synthesized by a modified sol-gel method. This series included five composites. The four composites were obtained by low- temperature hydrolysis, three of which were doped with fluorine in various ratios. The fifth composite was synthesized by direct precipitation. The adsorption activity of the composites has been studied toward glucose, phenol, cationic and anionic dyes. A significant increase of the adsorption capacity of all synthesized composites in comparing to the initial activated carbon has been found, despite its inner surface and porosity decreases due to modification. The observed increase of the adsorption activity is due to the fact; that adsorption on TiO2/activated carbon composites is accompanied by the simultaneous catalytic decomposition of adsorbed substances at the surface active centers, which are TiO2 particles. [ABSTRACT FROM AUTHOR]

New bismuth tellurite boro-germanate glasses according to composition xBi2O3-(80-x)TeO2-10B2O3-10GeO2 where (x=40, 45, 50, 55, 60 and 65 mol%) have been prepared by melt quench technique at 1150 ◦C. The room temperature optical absorption spectra have been recorded. The indirect band gap energy Eg was determined and found to decrease with Bi2O3 content. The increase in Urbach energy with glass composition indicates the decrease in structural stability. The ionic and covalent bonding parameters were determined. The present glasses are found to be 99 % ionic in nature. The two-photon absorption coefficient was found to increase from 11.89 to 14 cm/GW. The non-linear optical properties such as non-linear refractive index, linear optical susceptibility and third order non-linear optical susceptibility were evaluated using optical data. The authors determined theoretically the optical band gap (Eg) and refractive index (n) of the present glasses using optical electronegativity data. The relationship between Eg and n followed the relation Eg n4 = 99. The present glasses were found suitable for drawing optical fibers. [ABSTRACT FROM AUTHOR]

The Crystallization kinetics of Xanthan Gum Bio Polymer is studied by Differential Scanning Calorimetry (DSC) at different heating rates under non-isothermal conditions. The activation energy of crystallization (Ec) is evaluated, using different theoretical models (Starink, Ozawa, Matusita-Sakka, Piloyan and Coats and Redfern). The average value of Ec is found to be 231.38 kJ/mol. [ABSTRACT FROM AUTHOR]

This paper provides details regarding the preparation, optical absorption, emission and FTIR spectral studies on Dy3+ doped Li2O-CaF2−Al2O3− B2O3− SiO2 glasses. Absorption spectrum reveals different bands and it analyzed by the use of JO-theory. Emission spectra of the samples display two transitions 4F9/2→6H15/2, 4F9/2→6H13/2, a clear enhancement is observed with increase the concentration of Dy2O3 ions. The CIE coordinates is measured for these glasses it demonstrates that the glasses produce bright white light, which are appropriate for the improvement of the laser materials and white light LED's. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI)/Cobalt oxide (Co3O4) hybrid nanocomposites (NCs) were synthesized by means of in-situ polymerization using Cobalt nitrate as metal precursor, Polyaniline as polymerizing agent and Aloe-Vera (A.V.) gel as a fuel. The prepared nano composites were characterized by different characterization techniques such as Powder XRD, SEM and TEM. The electrical properties of PANI/Co3O4 hybrid NCs are very unique in comparison to the pure phases, PANI and Co3O4 nanoparticles (NPs), which were ascribed to the interaction between the PANI and Co3O4 nano particles. DC conductivity is observed to be enhanced as the Co3O4 NPs concentration increased from 10 to 50 wt% in the hybrid NCs at the different temperature. From the obtained measurements and data, the synthesized hybrid nano composites may be used in electronic device applications such as LED devices, solar cells and optical devices. [ABSTRACT FROM AUTHOR]

The blending of inorganic nanomaterials possessing high surface area with polymer systems to form hybrid materials is a promising category with abundant budding applications due to its exceptional mechanical, thermal and chemical stability. Herein, TiO2−Poly vinylpyrrolidone and TiO2−ZrO2−Poly vinylpyrrolidone composites are synthesized using sol-gel method and are allowed for electrospraying technique on aluminum foil and glass plates to get uniform film. FTIR spectroscopy and Elemental Mapping together confirm the constituents of the composite. FESEM and AFM revealed smoothness nature of the film. Contact angle measurements were carried out to assess self cleaning nature of the film. Antibacterial activity and oleophobic nature of the surface were also studied. The addition of ZrO2 prevents electron-hole recombination and enhances photocatalytic nature of the film. These works conclude that synthesized TiO2− ZrO2−PVP composite film shows excellent photoinduced self cleaning nature with better antibacterial activity. [ABSTRACT FROM AUTHOR]

In this paper, a polymer matrix composite (PMC) which is widely used in Aerospace, automobile and other engineering applications, which is reinforced with fly ash is taken in different weight ratios for manufacturing of Fly wheel cup. The principle target of this paper is to determine the behavior of fly wheel cup which is manufactured by deep drawing process using polymer matrix composite (PMC). In order to find the behavior of finite element analysis technique is used to find the deformation and equivalent elastic strain. Deformation of Fly Wheel Cup was found in the range of 0.0017 m – 0.008 m, and the level of equivalent elastic strain was found in the range 0.0087 – 0.04. And compared the results with Mild Steel, which is presently in use. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)/Polyvinylpyrrolidone (PVP) (50/50) blends filled with various concentrations of Copper Oxide (CuO) nanofiller (0, 2 and 4 wt %) were prepared using solvent casting technique. The structural properties were carried out using XRD. The UV Visible studies reveal that the direct energy gap values declines with an increase in CuO nanofiller concentration in the blend. The surface morphology studies were carried out using atomic force microscope (AFM). The photoluminescence spectra measured at an excitation wavelength of 220 nm reveals that the intensity of the spectra increases with filler concentration.The mechanical properties measured using Universal testing machine (UTM) indicates enhancement in the properties upon addition of CuO nanofiller. These significant enhancements in the optical and mechanical properties of the blend upon addition of CuO nanofillers make it a potential material for device applications. [ABSTRACT FROM AUTHOR]

We present a study of variation in the dielectric properties of polymeric blend films of polyacrylamide (PAM)/Polyvinylalcohol (PVA). Initially, the PAM and PVA were used to obtain apolymeric blend solution in distilled water. Preparation of blended films was conducted by a drying process. Films of pure PAM, pure PVA and blend films (w/w%) were characterizedby X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterizations revealed proper trends for the films depending upon weight percent (PAM: PVA: 20:80, 40:60, 60:40, 80:20). Variations in their dielectric property were investigated by use of a LCR (inductor capacitor resistor) meter. [ABSTRACT FROM AUTHOR]

A series of complex blended polymer films of poly (vinyl alcohol) (PVA) and poly (ethylene glycol) (PEG) with doping of various concentrations of active Sm3+ ions (1-5 mol %) were synthesized by the mechanism of solution casting technique. From the analysis of X-ray diffraction (XRD) and FTIR spectra, the structural analysis and molecular level interactions were observed, which results in reduction of the poly crystalline nature of the blended films. Scanning electron microscopy (SEM) studies reveals the uniform dispersion and coordinated complexes formation over the surface. Thermo gravimetric analysis (TGA) and Differential scanning calorimetric (DSC) analysis are used for examination of thermal behavior of the polymer blends, which shows enhancement in their thermal degradation and strength. The complex miscible polymer blends (PVA+PEG) doped with 5.0 mol % of Sm3+ ions are acting as a prominent host material for designing and development of opto electronic and luminescent devices. [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]

Electron paramagnetic resonance and optical absorption studies of xLi2O-(30-x)TeO2−10As2O3−60B2O3 glasses were made by introducing Cu2+ as spin probe. The EPR spectra of Cu2+ in all the glass samples recorded in the X- band frequency have similar spectral features. The variation in glass composition influences the spin Hamiltonian parameters calculated from the spectra. The spin Hamiltonian parameters indicate that the Cu2+ ions are coordinated with six ligand atoms in a distorted octahedron elongated along one of the axes and the ground state of the Cu2+ is dx2−y2 orbital. The optical absorption spectra exhibited a broadband corresponding to d-d transition bands of Cu2+ ion. The values of bonding parameters indicate a covalent nature of the in-plane σ bonding and pure ionic nature of the in-plane and out-of-plane π bonding. The theoretical optical basicity parameter values were evaluated, and it was observed that the value of Γσ increases, whereas Γπ decreases with the increase in optical basicity. [ABSTRACT FROM AUTHOR]

Electron paramagnetic resonance studies of the xBi2O3−(30-x)Li2O-10AS2O3−58B2O3 (where x=5, 10, 15, 20 and 25 mol%) containing 2 mol% V2O5 as the paramagnetic probe were carried out at room temperature. These glasses were prepared using conventional melt quenching. The amorphous nature of the prepared glass samples was confirmed by x-ray diffraction studies. From the EPR spectra, the spin-Hamiltonian parameters (SHP) of VO2+ ions, dipolar hyperfine parameter (P) and Fermi contact interaction parameter (K), molecular orbital coefficients (α2 and γ2), the number of spins participating in the resonance (N), and susceptibility (χ) have been evaluated. From the spin-Hamiltonian parameters, it was concluded that the vanadyl ions exist as VO2+ ions in octahedral coordination with tetragonal compression with C4V symmetry and the ground state is dxy. Tetragonality (Δg||/Δg1) of V4+ ion sites exhibited nonlinear variation in the glass composition in all the glasses studied. Further, the theoretical optical basicity of the glasses has also been evaluated and it is observed that the changes in optical basicity values are in accordance with the changes in SHPs. [ABSTRACT FROM AUTHOR]

Graphene and its composites are now reinforced with asphalt a pavement material to increase durability of roads. The present review paper focuses on improved performance of asphalt material when mixed with graphene, reduced graphene oxide and graphene nanoplatelets. Graphene is the world's versatile wonder two-dimensional material with countless multifunctional applications in electrical, physical, biomedical, chemical and in mechanical fields. High economical expenditure in roads maintenance in all climatic conditions, high traffic loads, resistance to wear and tear are the challenges for construction engineers. The objective of the paper is to bring awareness and understanding of increased performance of asphalt when reinforced with graphene. Various parameters like aging resistance, marshall stabilityand high temperature stability were reviewed in the present study. [ABSTRACT FROM AUTHOR]

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]