Determination of RF source power in WPSN using modulated backscattering

A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. During RF transmission energy consumed by critically energy-constrained sensor nodes in a WSN is related to the life time system, but the life time of the system is inversely proportional to the energy consumed by sensor nodes. In that regard, modulated backscattering (MB) is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. Hence wireless passive sensor networks (WPSN) designed to operate using MB do not have the lifetime constraints. In this we are going to investigate the system analytically. To obtain interference-free communication connectivity with the WPSN nodes number of RF sources is determined and analyzed in terms of output power and the transmission frequency of RF sources, network size, RF source and WPSN node characteristics. The results of this paper reveal that communication coverage and RF Source Power can be practically maintained in WPSN through careful selection of design parametersComment: 10 pages; International Journal on Soft Computing (IJSC) Vol.3, No.1 (2012). arXiv admin note: text overlap with arXiv:1001.5339 by other author

Multi response Characteristics of Process Parameters during End Milling of GFRP using Grey-Based Taguchi Method

This paper deals with optimization of surface roughness and delamination damage on GFRP  material during end milling using grey - based taguchi method. Three parameters namely spindle speed, feed rate and depth of cut were identified and ranges of the parameters for the present investigation were determined from preliminary experiments. Taguchi method based on L9 orthogonal array was selected and experiments were conducted as per experimental layout plan. The experiments were carried out on a CNC vertical machining center to perform 10mm slots on GFRP work piece of 300mmX50mmX25mm size by K10 carbide, four flute end milling cutter. Surface roughness and delamination damage were measured on each slot with the aid of form Talysurf 50 and tool maker’s micro scope. An optimal combination of process parameters were obtained via grey based taguchi method. From the results of ANOVA, it is concluded that cutting speed and depth of cut are the most significant factors affecting the surface roughness and delamination damage factor and their contribution in an order of 26.84% and 40.44% respectively. A confirmatory experiment shows that 5.052µm for surface roughness and 1.682 delamination damage factor to validate the used approach after conducting with optimal setting of process parameters

American Research Library – A Digital Research Library of R&D World

This paper depicts the profile of American Research Library (North American Research Library Network) –NARESLIBNET as Conference of American Research Librarians – CARAL at International Institute for Research and Development-IIRND USA aims to provide research and development information to the researchers and academics worldwide. Unified access to global researchers in a variety of research institutions and libraries. ARL Service offers integrated discovery of and access to the collections, products and services of American Research Libraries. It is aimed at users world-wide who want a powerful and easy way of finding research and development resources. ARL as Digital Research Library online portal offers quick and easy access to the collections

Role of Information Technologies in Electronic Information Transfer and in Providing Value Added Information Services

Information Technology plays an important role in electronic. message transfer, electronic data interchange (EDI), electronic files transfer protocols, transfer of voice, text and images through ISDN, remote electronic information access and retrieval, and the enforcement of research, education and distance learning through 'virtual global university'. In future, these information technologies can engage in interactive TV, picture phones and TV/PCs purchase. Findings of a survey, conducted to determine the potential. use, non-use and non-availability of IT service in different libraries/documentation centres are also given

Joining of Dissimilar alloy Sheets (Al 6063&AISI 304) during Resistance Spot Welding Process: A Feasibility Study for Automotive industry

Present design trends in automotive manufacture have shifted emphasis to alternative lightweight materials in order to achieve higher fuel efficiency and to bring down vehicle emission. Although some other joining techniques are more and more being used, spot welding still remains the primary joining method in automobile manufacturing so far. Spot welds for automotive applications should have a sufficiently large diameter, so that nugget pullout mode is the dominant failure mode. Interfacial mode is unacceptable due to its low load carrying and energy absorption capability. Strength tests with different static loading were performed in, to reveal the failure mechanisms for the lap-shear geometry and the cross-tension geometry. Based on the literature survey performed, venture into this work was amply motivated by the fact that a little research work has been conducted to joining of dissimilar materials like non ferrous to ferrous. Most of the research works concentrated on joining of different materials like steel to steel or aluminium alloy to aluminium alloy by resistance spot welding. In this work, an experimental study on the resistance spot weldability of aluminium alloy (Al 6063) and austenitic stainless steel (AISI304) sheets, which are lap joined by using a pedestal type resistance spot welding machine. Welding was conducted using a 45-deg truncated cone copper electrode with 10-mm face diameter. The weld nugget diameter, force estimation under lap shear test and T – peel test were investigated using digital type tensometer attached with capacitive displacement transducer (Mikrotech, Bangalore, Model: METM2000ER1). The results shows that joining of Al 6063 and AISI 304 thin sheets by RSW method are feasible for automotive structural joints where the loads are below 1000N act on them, it is observed that by increasing the spots per unit length, then the joint with standing strength to oppose failure is also increased linearly incase of interfacial failure mode and non linear for pullout failure mode.

Optimization of Burr size, Surface Roughness and Circularity Deviation during Drilling of Al 6061 using Taguchi Design Method and Artificial Neural Network

This paper presents the influence of cutting parameters like cutting speed, feed rate, drill diameter, point angle and clearance angle on the burr size, surface roughness and circularity deviation of Al 6061 during drilling on CNC vertical machining center. A plan of experiments based on Taguchi technique has been used to acquire the data. An orthogonal array, signal to noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate machining characteristics of Al 6061 using HSS twist drill bits of variable tool geometry and maintain constant helix angle of 45 degrees. Confirmation tests have been carried out to predict the optimal setting of process parameters to validate the used approach, obtained the values of 0.2618mm, 0.1821mm, 3.7451µm, 0.0676mm for burr height, burr thickness, surface roughness and circularity deviation respectively. Finally, artificial neural network has been applied to compare the predicted values with the experimental values, good agreement was shown between the predictive model results and the experimental measurements

Tunneling phenomenon in heterostructure devices

A theoretical formulation for carrier current across hetero-interface in heterostructure semiconductor devices is presented using tunneling as the phenomenon. An analytical expression for the transmission coefficient as a function of energy using the Airy\u27s function and exponential solutions to Schroedinger\u27s equation for a linear potential variation is used in the calculations. This thesis addresses two theoretical problems: physics and modeling of gate current dependance on gate voltage in a heterostructure insulated gated field effect transistor (HIGFET) and, oscillations in the current-voltage characteristics of a double heterostructure bipolar transistor (DHBT); For HIGFETs, two components of tunneling currents, one from the decay of the quasi-bound resonant states in the accumulation well and the other from the tunneling electrons with kinetic energy above the bulk energy level, were considered. Moreover, the possibility of hot electrons is addressed. The reason for the large discrepancies between the experimental values and the theoretical values reported in earlier literature is attributed mainly due to the exclusion of the hot electron mechanism and the neglect of the contribution to current from the decay of the resonant states in the accumulation well; The origin of oscillations in the collector saturation current of a DHBT (with a set back layer) is investigated theoretically. Energy band balance was performed at the base-set back layer and set back layer-collector junctions to determine the distribution of the output voltage, {dollar}V\sb{BC}{dollar}, at these junctions and the conduction band edge profile using degenerate statistics. Theoretical results are in excellent agreement with the experimental results with {dollar}V\sb{BC}{dollar}\u27s at which the first two peaks of the {dollar}I\sb{D,sat}{dollar} occur matching closely. (Abstract shortened by UMI.)