Simultaneous measurements of thermal transport properties of twin pellets of Se75Te15-xIn10Znx (0≤x≤15) multicomponent chalcogenide glasses were performed across a temperature range from ambient to 323K using the transient plane source (TPS) method. The measurements showed that effective thermal conductivity (le), effective thermal diffusivity (χe), and phonon mean free path (τ) slightly decrease as temperature rises. In contrast, the specific heat per unit volume (ρCp) remains relatively stable with temperature for each sample. An empirical model was established to provide a theoretical interpretation of these findings. Additionally, key physical parameters-such as theoretical density, mean atomic volume (Vm), molar mass (M), compactness (d), average coordination number cohesive energy (CE), and mean bond energy were calculated for the synthesised chalcogenide samples. The composition-dependent values of λe, χe, ρCp, and τ were analyzed for the entire chalcogenide network. Results indicate that λe increases with increasing Zn concentration in the quaternary network, while χe, τ, and ρCp exhibit a non-monotonic trend and attain a minimum and a maximum at 10 at. wt.% of Zn, respectively.

A single scan has been performed in Differential Scanning Calorimetry (DSC) at a heating rate of 15oC/min under non-isothermal conditions to investigate the crystallization kinetics of glassy Se90Sb10-xAgx alloys (where x = 2, 4, 6, 8). For this purpose, Handerson’s theory based on non-isothermal method for thermal analysis of single-scan DSC data has been used. The activation energy of crystallization and order parameter has been determined and composition dependence of these parameters has been discussed.

Les oxydes de metaux de transition a structure perovskite ABO3 presentent des degres de liberte structurels et electroniques fortement enchevetres. On s'attend donc a decouvrir des phases et des proprietes exotiques en agissant sur le reseau par le biais de divers stimuli externes. L'ingenierie des contraintes epitaxiales dans les couches minces d'oxydes est un moyen important d'adapter la distorsion du reseau cristallin par l'effet cooperatif de Jahn Teller. En utilisant les couches minces actives PrVO3 de Jahn Teller comme systeme modele, la correlation structurelle avec le magnetisme est etablie. Nous imposons differentes contraintes de contrainte epitaxiale dans les films minces PrVO3 via differents moyens, tels que, en utilisant divers substrats monocristallins disponibles dans le commerce, l'epaisseur du film, des substrats avec des orientations de surface cristallines differentes, etc. En consequence, des phases nouvelles et cachees, absentes du compose en vrac, commencent a apparaitre. Notamment, la contrainte de compression dans les films de PrVO3 ameliore l'interaction de super echanges menant a une augmentation de la temperature de Neel antiferromagnetique, une forte anisotropie magnetique dans les films minces de PrVO3 cultives sur des substrats SrTiO3 orientes (001), 110 et 111, sont quelques exemples.

Increase in land and air pollution during the conversion of energy sources of fossil fuel such as oil, coal and natural gas have their adverse effects on environment and ecology. Depleting quality of these sources raises the question of sustainability in the long run, there by compelled humanity to go in search of the other alternatives. In this context, the solar sources of energy have attracted the global attentions and evoked interest among policy makers as a viable option for sustainable development. Electricity production accounts for more than 50% global warming emission with the majority generated by coal fired power plants in the world. Natural gas power plants produce more than 10% total emission in the world. In contrast to this, most renewable energy and nonconventional sources produce very little global warming effects. 46% out of 130 crore population of India live in rural and far flung areas and survive on kerosene, wood for fire and cooking or nonconventional sources of energy as their primary sources. It is hurting to know that India loses nearly $18 billion annually in power sector which is sufficient to provide 490 million, free electricity for a year through micro-grid. As the world moves to cleaner energy sources and water becomes increasingly valuable commodity in many regions, it will influence the choice of energy options. Here in this article, effort has been made to project the overall scenario of solar energy sources and their utility in remote areas where conventional energy cannot reach. In this paper, description has been made of the module of solar energy manufactured using solar panel, and inverter to convert the DC energy to AC energy and to store the energy in a special type of battery. The power so stored can be utilized during night to light the bulb and a fan which is the minimum requirement of the people living in the far-flung areas. The article also refers to the research and innovative measures required to be undertaken to supply power to the masses in far-flung areas and high lights the challenges faced during supply of power. Keywords: Solar energy, far-flung, challenges, geothermal, canal banks Cite this Article Darde PN, Arvind Kumar, Jayant Kumar et al. Harnessing Solar Energy to Supply Power to Far Flung Areas and Challenges. Journal of Alternate Energy Sources and Technologies. 2017; 8(3): 50–58p.

Alloys of Se100-xSb10-xAgx (x=2, 4 &8) glassy system have been obtained by quenching technique. Kinetic parameters, which represent thermal stability, have been determined from differential scanning calorimetric technique. The rate of crystallization decreases with Ag concentration and is lowest for glassy Se90Sb2Ag8 alloy. Thermal stability (T-c-T-g), Hruby criterion H-r Saad Poulain 'S' have been found to increase with Ag concentration and are maximum for Se90Sb2Ag8. Thus, one can conclude that the rate of crystallization is related to the thermal stability. The reduced glass transition temperature for Se90Sb10-xAgx is found to be 2/3, which shows that these glassy alloys are suitable for phase change optical memories.

The optical constants like refractive index (n), real dielectric constant (epsilon'), extinction coefficient (k), imaginary dielectric constant (epsilon''), absorption coefficient (alpha) have been studied for Se90In10-x Ag-x films (where x= 2, 4, 6, 8) in the wavelength range 400-1200 nm. The transmission spectra, T (lambda) of the films are obtained by spectrophotometer. Swanepoel method is used to calculate the optical constants and they are plotted as a function of wavelength. It is found that n, epsilon', epsilon'', k, alpha decrease with increase in wavelength. Band gap was found to increase with the increase in Ag concentration.

Glassy alloys of Se90Sb10 are prepared by melt quenching technique. The amorphous nature of the so prepared alloy is confirmed by X-ray diffraction technique. Se90Sb10 pallets are prepared by compressing the fine powder of glassy alloy in a die up to a load of about 5-6 tons. The a. c. conductivity and dielectric properties of these samples are studied in the temperature range (308 K-373 K) and frequency range (500 Hz-500 kHz). It has been observed that the a. c. conductivity sigma(ac)(omega). proportional to omega(s) where s is found to be less than unity. It has been observed that the values of dielectric constant and dielectric loss are temperature dependent and decreases with the increase in temperature. Applying Guintini's criteria the maximum barrier height has been calculated and found to be 0.15 eV which is in close agreement with the theory of hopping conduction over potential barrier as suggested by Elliott. A close resemblance is found between theoretical and experimental results which are explained on the basis of correlated barrier hopping (CBH) model. The experimental data has been fitted to the theory of a. c. conductivity, and density of charged defect states has been estimated for the glass under consideration. In the present case it has been observed that bipolaron hopping dominates over single polaron hopping, which is explained in terms of lower value of potential barrier.

The micro-hardness (H-V) of chalcogenide glasses is one of the significant parameters that are used to determine their utility for device applications in optics and opto-electronics. The present paper reports the effect of Ag on some micromechanical parameters of Se90In10-xAgx (0 <= x <= 8) glassy alloys. The glass transition temperature (T-g) of these glassy alloys is determined by differential scanning calorimetry. Using the existing model based on free volume theory and knowing the experimental values of H-V and T-g, other thermo-mechanical parameters [the minimum volume of micro-voids (V-h), modulus of elasticity E, the energy of their creation (E-h)] are also calculated. The composition dependence of Vickers hardness and elasticity has been discussed.

The paper reports the role of Ag additives on light induced metastable defects in Se–In glassy alloys using a well-known thermally stimulated current (TSC) technique. Amorphous thin films of Se90In10−xAgx (x=0, 2, 4, 8) were prepared by thermal evaporation. Measurements were made in the given thin films prior to and after exposing amorphous thin films to white light for different exposure times (0–1.5hrs). The density of light induced metastable defects increases with exposure time, and the fractional increase in light induced metastable defect density decreases as Ag concentration increases.

The present paper reports the space charge limited conduction (SCLC) measurements in Se90Ge10-xInx (x = 2, 6) amorphous thin films. For this purpose, I-V measurements have been taken at different temperatures. The results show that an ohmic behavior is observed at low electric fields (E < 10(3) V/cm) while, at higher electric fields (E similar to 10(4) V/cm), a super-ohmic behavior is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the present glassy materials. Density of defect states (DOS) near Fermi level is calculated by fitting the data to SCLC theory. The peculiar role of the third element Indium, as an impurity in Se90Ge10 binary glassy alloy, is also discussed in terms of electro-negativity difference between the constituent elements.

This review paper describes optical and electrical properties of Chalcogenide glasses. By the virtue of these properties, these glasses have been incorporated in various semi-conducting electronic devices like optical memory, thin-film transistors and the scope of research and development is still extant. The electrical properties discussion includes trends and theories associated with AC/DC conductivities, defect states, dielectric losses and thermally stimulated currents (TSC). In addition, various theories explaining localized states and band gap like Poole Frenkel, Space Charge Limited Current (SCLC), hopping conduction etc. have been introduced. The optical properties summarize methods of measurement of optical band gaps, optical constants and photoconductivity variations in different glasses.

An attempt is made to investigate light induced defects (LID) in amorphous chalcogenide Se90Ag10 thin films prepared by vacuum evaporation technique. For the determination of light induced defects quantitatively, space charge limited current (SCLC) measurements have been made in a vacuum similar to 10(-3) Torr before and after exposing amorphous films to white light for different exposure times (0 to 6 hours). Results indicate that light induced defects are created due to prolonged exposure of light which is explained by a microscopic model for light induced defects creation proposed by Shimakawa and co-workers.

Present study reports the quantitative estimation of light induced defects in vacuum evaporated thin films of Se90In2Ag8 by using thermally stimulated current (TSC) technique. These Measurements have been made in a vacuum similar to 10(-3) Torr before and after exposing amorphous films to white light for different exposure times from 0 to 1.5 hours. It is found that the density of light induced defects increases with the exposure time.

The present paper reports the study of semiconducting parameters (activation energy and pre-exponential factor) in glassy samples of Se90X10 (X=Ag, In) in dark as well as in presence of light. Temperature dependence of dark and photo-conductivity is measured in amorphous thin films in the temperature range 300-378 K and in the intensity range 2000-18000 Lux. A straight line between ln sigma(0) and Delta E indicates the presence of Meyer - Neldel (MN) rule in dark as well as in presence of light. Linear dependence of ln(sigma(0)) on Delta E in case of amorphous material indicate that the conduction band tails a finite energy distance towards the valence band and a Fermi level which is controlled by fixed dominant hole levels deeper in the gap.

An attempt is made to observe light induced defects (LID) in amorphous chalcogenides Se90X10 (X=Sb, In, Ag) thin films prepared by vacuum evaporation technique. For the determination of light induced defects quantitatively, space charge limited current (SCLC) measurements have been made in a vacuum ∼10−3Torr before and after exposing amorphous films to white light for different exposure times (0 to 6h). Results indicate that light induced metastable defects are created due to prolonged exposure of light which is explained by a microscopic model for light induced metastable defects creation proposed by Shimakawa and co-workers. Fractional increase in density of defects due to light exposure is found to be least in case of Se90Ag10 indicating that this alloy may be used for optoelectronic applications as degradation upon light soaking is small in this case.

The aim of this article is to introduce a new analytical and approximate technique to obtain the solution of time-fractional Navier–Stokes equation in a tube. This proposed technique is the coupling of Adomian decomposition method (ADM) and Laplace transform method (LTM). We have consider the unsteady flow of a viscous fluid in a tube in which, besides time as one of the dependent variable, the velocity field is a function of only one space coordinate. A good agreement between the obtained solutions and some well-known results has been demonstrated. It is shown that the proposed method robust, efficient, and easy to implement for linear and nonlinear problems arising in science and engineering.

The aim of this article is to introduce a new analytical and approximate technique to obtain the solution of time-fractional Navier–Stokes equation in a tube. This proposed technique is the coupling of Adomian decomposition method (ADM) and Laplace transform method (LTM). We have consider the unsteady flow of a viscous fluid in a tube in which, besides time as one of the dependent variable, the velocity field is a function of only one space coordinate. A good agreement between the obtained solutions and some well-known results has been demonstrated. It is shown that the proposed method robust, efficient, and easy to implement for linear and nonlinear problems arising in science and engineering.