Archives-April 2015

Zinc oxide nanostructure were successfully synthesized by chemical method and deposited on Al2O3 substrate using PLD. XRD analysis demonstrated that the ZnO nanostructure has a wurtzite structure with orientation of (002). SEM results indicated that by increasing the calcined temperature, the dimension of the ZnO nanostructure increases. The optimum temperature for synthesizing high density ZnO nanostructure was determined to be 1250 K. Room temperature PL spectra of the ZnO nanostructure showed a strong UV emission peak located at around 380 nm and a relatively weak green emission at around 540 nm, confirming that the as-grown nanorods possess good optical properties. The sensitivity of zinc oxide NRs films to 50 ppm vapor NO2 gas as a function of working temperature with different doping.

The thermal evaporation system type (Edwards) has been used to evaporate high purity (99.9 %) silver on glass substrates at room temperature under low pressure (about 10-6 torr) for different thickness (50, 75, 100, 125 and 150) nm. Using a rapid thermal oxidation (RTO) of Ag film at oxidation temperature 350 oC and different oxidation times, Ag2O thin film was prepared. The optical properties of Ag2O film were investigated and compared with other published results. The gas response behaviors of the p-Ag2O/PSi/c-Si – based gas sensor to H2 gas were investigated. The film gas response dependence on the temperature and test gas concentration was tested.

The range of brightness levels and Histogram shows how individual brightness levels are occupied in any image, for image contrast measurement .Low-level image processing is one of the most important issues of image enhancement. To control and enhance the contrast, Histogram Equalization (HE) is the simple and effective technique, but this approach causes some unnatural look in output image. For best effect the brightness of input image must be retained. Fuzzy techniques can manage the vagueness and ambiguity efficiently. Fuzzy logic is a powerful tool to represent and process human knowledge in form of fuzzy if-then rules. In this work we are using fuzzy membership function in the proposed algorithm. The proposed concept in this paper is named as Brightness Preservation by Fuzzy based Multi-peak Generalized Histogram Equalization (BPFMGHE) and it is simulated by MATLAB; this technique first combined the global histogram equalization of image with local information and then after calculating noise free generalised multi-peak histogram by equalization, the image was again decomposed into several sub-images, and then applied the fuzzy membership function dependent HE process to each of them to preserve image brightness.The distribution of grey level is in complete control with the given method and image improvement is effective. Image is improved and brightness is preserved effectively with the discussed process.

This paper emphasizes on the measurement of mutual fund performance and timing abilities of income fund managers in Pakistan. To analyze the income fund performance Treynor measure is used which assumes that fund managers possess diversified portfolios. Timing abilities are ascertained by using Treynor and Mazuay measure and data for five years ranging from July 2009 to June 2014 is used and it consists of 30 income funds. Results showed that 23 of the total income funds had positive treynor values which indicate good performance and also an indicator of better diversification. Treynor and Mazuay measure also had a better indication of timing abilities as 2/3rd of the managers performed well in this regard.

In this paper the transmitter intelligently adapts the transmission parameters like coding scheme, modulation symbol, power etc. w.r.t the varying wireless CSI. If channel is having poor transmission conditions then a channel code with smaller code rate and a smaller modulation symbol can be used. Similarly, if channel conditions are good, a comparatively high code rate or even no coding need be used. Paper gives an overview about the WiMAX standard and studies the performance of a WiMAX transmitter and receiver.

Piezoelectric materials offer a promising approach to reduce our dependence on conventional source of electricity. Crowd Farming can be a useful technique to extract power from piezoelectric materials. In our work, calculation have been made based on piezoelectric flooring system in crowded area, as the source of pressure is the footsteps of the crowd. Further from the literature study on piezoelectricity, one footstep can provide electrical energy to light two 60-watt bulbs for one second and the effect of large number of people on piezoelectric floor can generate electricity of substantial quantity.

An analysis is presented to investigate the Dufour, soret and thermophoresis parameter effects on MHD Mixed convection, heat and mass transfer about an isothermal vertical flat plate embedded in a fluid-saturated porous medium in the presence of viscous dissipation. The similarity solution is used to transform the problem under consideration into a boundary value problem of coupled ordinary differential equations, which are solved numerically by using the finite difference method. Numerical computations are carried out for the non-dimensional physical parameter. The results are analyzed for the effect of different physical parameters such as Dufour number, Soret number, thermophoretic, MHD, mixed convection, Eckert number, inertia parameter, buoyancy ratio, and Schmid number on the flow, heat, and mass transfer characteristics.

In this paper a power and area efficient design of 32:1 tree type multiplexer has been designed by hybridizing GDI and PTL techniques. Multiplexer circuit using this technique consumes less power in comparison to the CMOS, TG and other logic design techniques. The proposed design consists of 63 NMOS and 31 PMOS. At 1.2 V power supply the proposed MUX design consumes 47.093 ?W power on BSIM-4 and 47.09 ?W power on LEVEL-3 with simulation length of 5n. The proposed multiplexer is designed and simulated using DSCH 3.1 and MICROWIND 3.1 on 180nm.

The aim of the present study is to investigate the optimum operating temperature of a compression ignition (CI) engine that will operate with the minimum level of exhaust emissions. The blends of jatropha with diesel in varying proportions (B10, B20 and B40) are prepared and are investigated in CI engine test rig. The result of engine emissions like CO2, CO, HC and NOx of pure diesel and biodiesel and their blends are shown by various graphical representations with respect to the engine coolant temperature at different engine loads. From the present study, it can be inferred that it is preferable to operate the engine at temperature 65?C-80?C.

Traditionally the name Rhizobia portrays root and stem nodulating bacteria that live in N2 fixing symbiosis mainly with leguminous plants. Understanding rhizobial diversity at classical and molecular level could have a profound implication in agriculture. Hence, the present study is aimed at isolation, identification, biochemical and molecular characterization of rhizobia from the fourteen different soil series of Thanjavur district. All the test isolates showed uniform morphological and biochemical characteristics except colony size and isolates growth on YEMA containing bromothymol blue medium, revealed that Vlm6 and Mud8 isolates were fast growers while others were slow growers. Based on morphological, cultural and biochemical characterization, all the isolates were preliminarily identified as species of Rhizobium. The soil samples from the 14 different sites showed variation not only in the number of colonies per gram of soil, but also in their physico-chemical properties. Positive correlation was noted between physicochemical parameters such as bulk density, EC, organic carbon, nutrients such as N, K, Cu and number of rhizobial colonies. Negative correlation was observed with soil pH, nutrients such as P, Fe, Zn, Mn and number of colonies. However, the relationship is not statistically significant in the present study. The isolates showed variation in their carbon utilization, fatty acid and amino acid profiles confirming the existence of diversity.