Transparent conducting oxides (TCOs) have become an essential part of today’s life through their application in touch screen technology. The growing interest for superior and cheap transparent conducting films, primarily driven by the smart televisions and phones market, has led to renewed efforts to develop novel TCOs. Currently, the most widely used material for transparent conducting applications is Sn-doped indium oxide (ITO), but this material is expensive. Al-Doped zinc oxide (AZO) is among the few metal oxides which can replace costly tin doped indium oxide (ITO) due to many properties similar to it. Thin films of AZO of different thickness 100 nm, 200 nm, 300 nm were deposited on glass substrates using Al doped ZnO target by RF magnetron sputtering system and 15 nm Zn layer on top of it by DC magnetron sputtering system and annealed in inert environment. These films show a carrier concentration of 2.28× 1021 cm-3 , mobility of 27 cm2 /V-s and resistivity of 10-4 Ω-cm. Such a low value of resistivity is attributed to a dense compact columnar morphology of the sputtered films as evident from FESEM micrograph. The nanocolumns of such close proximity with higher surface related defects increase the carrier concentration enormously. As a result, compact columnar structure improves conduction process and increases electrical conductivity which is comparable to the standard TCO characteristics used in the optoelectronic devices.
Keywords: Al-doped, ZnO Thin films, AZO, Sputtered.

Electronic structure calculation has been carried out for quantum spin system Sr2Fe3S2O3 with an aim to figure out the underlying spin model. We present first-principles density functional calculation to study the electronic and magnetic properties of Sr2Fe3S2O3. We discuss explicitly the nature of the exchange paths and provide quantitative estimates of magnetic exchange couplings. A microscopic modelling based on analysis of the electronic structure of this system puts it in the interesting class of 2-D antiferromagnetic spin S=2 ladder system.
Keywords: Spin ladder system, Electronic structure, Magnetic exchange interactions, Spin model.

In this paper, Gorter-Casimir (GC) two fluid model for low temperature normal superconductors is modified introducing phononic term along with electronic term in the normal phase free energy. The exponent corresponding to the normal phase fraction is changed from 1/2 to a general value n which can be different for different materials. n is a parameter which tunes how much portion of normal phase free energy will be reduced to form superconducting phase by condensation of normal electrons into super-electrons at some finite temperatures below superconducting transition temperature (TC) and the electron-phonon interaction is the controlling factor which calibrate the values of n. This present model describes the idea of different jump ratios of specific heat of different materials at T = TC, which GC model cannot predict. We have adopted a new concept of “Phase diagram” from which an idea of a new temperature T∗ has been obtained. Modified GC model explains well the resistivity behavior near TC. Moreover, for some high temperature superconductors along with the electronic and phononic contribution, a low temperature Schottky contribution is added to the free energy density. However, the contribution is negligible near TC.
Keywords: Superconductors; Electron-phonon interaction; Two-fluid model.

We solve the Euler equations in one and two dimensions using a central compact scheme coupled with an AUSM+ algorithm. The compact scheme is used in the form of a cell-face interpolation scheme to create the left- and rightstates of the primitive variables required by the AUSM+ based solver. We invoke a TVD limiter to locally apply smaller stencil low-order dissipative formulae near shocks. No extra high-order artificial dissipation is added to stabilize the computation. A number of one and two dimensional test cases has been solved to show the effectiveness of this approach.
Keywords: Euler equations; central compact scheme; AUSM+ ; TVD limiter; shock capturing

Plasma arc welding (PAW) uses non consumable tungsten electrode and arc is formed between electrode and workpiece.Shielding gas can be separated from plasma arc by placing the electrode within the body of the torch. Among different welding processes, plasma welding has various advantages like non-contact, high welding quality, narrow heat-affected zone, deep penetration etc which makes it superior to the commonly used processes. Plasma welding has broad range of applications in different engineering field. This present research work provides an overview of the effects of plasma arc welding and its various parameters on different materials. The heat transfer during plasma arc welding to the work piece has significant effect upon the weld material quality. This research work also reviews the heat transfer modeling of plasma arc welding that had been developed by researchers for prediction of better weld geometry and weld quality.
Keywords: : Plasma Arc Welding, Process Parameters, Modeling, Materials

Metal Inert Gas (MIG) welding is a widely employed arc welding process that uses a consumable metal electrode to produce the weld. MIG welding produces very good quality weld when compared to other welding technologies with precise welding and comparatively little heat affected zone. MIG welding has become a popular choice of welding processes when high quality, precision welding is required at a comparatively lower cost. MIG welding is dependent on various input parameters but in the present work input parameters selected were welding current and weld time because these are the two major parameters which affect the weld quality. MIG welding finds its greatest application in welding both ferrous and non-ferrous metals and thus the most widely used arc welding process. A Taguchi Method (2 factors 3 levels) Design of Experiment (DOE) has been applied in this context to examine different welding defects through various tests like Hardness, Ultrasonography, Dye Penetration Test and tensile testing to examine its effect in each case. Finally using the Taguchi results have been optimized and through experiments and testing the best alternative with minimum welding defects and maximum yield strength and hardness number is reported successfully in the present work.
Keywords: Metal Inert Gas welding, welding current, welding voltage, Taguchi Method, yield strength, hardness number

CNT based material are of vital importance in modern technology for their superior physical and chemical properties. In recent times, material developments for energy applications are focused for improvement of battery, capacitors, and electrodes for enhanced efficiency. High performance Supercapacitors with high energy densities are at the leading edge for renewable energy engineering device sector. CNT based Ni-Co-O material is of keen interest due to its possible applications as supercapacitors, electrocatalyst for metal/air battery and others. The hybrid material synthesis, morphology features and electrochemical features are vital to evaluate the material performances for energy applications. Electrical studies are also vital to evaluate the properties for device applications. In the present article, some stresses have been laid forward for the development of CNT-Ni-Co-O based hybrid material for supercapacitor high energy density applications.
Keywords: Ni-Co-O, CNT, Supercapacitor, Cyclic voltammetry.

In this age of highly memory intense applications and increasing size of Random Access Memory (RAM), mobile Central Processing Unit (CPU) temperatures are bound to reach high values; the range can even extend up to 48 degree Celsius. In that case, it would only be logical to try and harvest that heat energy, which could help in the phone's performance by actually cooling the device down and simultaneously it can be charged through converting this heat energy into electrical energy. When mobile phones are being charged by motion as well, heat should not be left behind because it is one of the most thermodynamically underappreciated sources of energy. In this paper, a Peltier Module has been used to capture heat from the CPU or the surroundings to generate a voltage that will supply power to the battery. The advantages of this method includes that a phone can be charged at anyplacewhere no power source is available. The only disadvantage in this method would be a low efficiency, because heat itself is of very low quality energy source.
Keywords: Boost Circuit, CPU, Efficiency, Heat Energy, Peltier Module, Seebeck Effect

In the last few decades the wastage of food items is due to insufficient cold storage facilities in India. This is largely due to the high electricity costs of vapor compression refrigeration cycles. This has prompted to use the alternate refrigeration cycles. This paper is devoted to using magneto-caloric effect of ferromagnetic materials for maintaining the temperature about 280K so as to keep the perishable items preserved for some period of time.The main objective of this type of refrigeration is use of solid refrigerant called magneto caloric material. This type of material can increase or decrease the temperature when they are magnetized or demagnetized. Magnetic refrigeration systems are like traditional cooling units, but they don’t use as much electricity which make it highly efficient to be use for cold storage system. The effect of solid state refrigerants, water based heat transfer fluids increases the efficiency with minimum contribution to global warming & ozone depletion making it highly sustainable which is the need of the hour.
Keywords: Green refrigerating system, Magneto-caloric refrigeration, cold storage system, global warming,Erricson cycle

Bulk acoustic wave device are considered now as a high resolution analytical tools for the real time monitoring of small amount of surface attached mass of bio molecules. Among various mass sensor, acoustic sensors are playing a pivotal role due to their high sensitivity to mass change, easier in packing and potentially low manufacturing cost. Piezoelectric biosensor is a kind of BAW device that utilize longitudinal wave, known as thickness shear mode that propagates in the bulk of materials. The gravimetrical measurement performed with the piezoelectric biosensor provides the high precise experimental data. This experimental data is used for quantification of surface mass of the piezoelectric crystal substrate and additional mass applied to the oscillating surface. The theoretical modelling is important for the quantative analysis and interpretation of the experimental data. For BAW device, a linear relationship is sustained between the shift in resonance frequency and surface mass which cause this shift. But for liquid medium, viscoelastic effect is introduced with the linear relation. Through the formulation of the theoretical modelling it is possible to show the necessary correction factors of surface mass deduced from BAW device measurement in liquid. Theoretically obtained result must be compared with the experimental value for the liquid phase measurement.
Keywords: acoustic sensors, resonator, biomolecules