IMPACT : International Journal of Research in Engineering & Technology

1-6

Authors: A. D. Bhosale & Marathe Dagadu Mitharam

Computers are commonly used items in many areas. The computer is one of the most powerful forces in organization today. Computers impacted in organization in many ways. Organization received some benefits using computer (Greater Efficiency, Higher Quality products, Better service, Recreational and educational benefits, Better information retrieval, fast working, Accuracy etc) In this paper show some benefits as well as positive impact of computers on organization.

9-12

Authors: Nempal Singh, Jitendra Singh, Sachin Kumar, Manoj Kumar, Ansul Gaur & Kapil Sirohi

In the present paper the thin film of CdS and Polyaniline has been developed by vacuum evaporation technique. The prepared thin films then deposited onto glass as well as metallic substrates. The glass substrate was cleaned in aquaregia, washed in distilled water and isopropyl alcohol (IPA). These prepared samples were then subjected for the electrical measurements by employing Keithley electrometer. In PANI/ CdS junction the conduction of charge across the junction is typically a mixture of electron from n-CdS side a polaron and bipolaron from p-Pani side. The n-CdS and p-Pani heterojunction also holds the promises of being studied and converted in to an active device. The low value of fill factor and conversion efficiency can be attributed to the polycrystallinity of the CdS thin film and vacuum deposited Pani thin film, as they do not make an extremely sharp perfect heterojunction. Also the substrate has a strong influence on the surface morphology of the films.

21-34

Authors: Krishna Prasanth K & Muruganantham P

In launch vehicle structures design, importance is given to lightweight with high load bearing capacity design, so the factor of safety is kept low compared with ground-based structures and at the same time maintaining high reliability. This demands very accurate analysis of structural elements for launch vehicle. The main criteria are lightweight, ease of fabrication, lower cost and at the same time meeting the strength and stiffness requirements. The commonly used launch vehicle structure is the closely stiffened structure in which the structure consists of 90 or 120 no’s of stringers riveted onto a 1.2mm thick skin and a few number of bulkheads. In this type of structures, thin shell can buckle or cripple at a load much lower than the buckling strength of stringers. In order to overcome this, integrally stiffened structures such as isogrid structures is chosen. Isogrid is the name given to integrally, grid stiffened shell and structures in which the grids form an equilateral triangle pattern. The isogrid structure can withstand both compressive and bending loads and also offers lower weight and higher structural efficiency. A typical inter tank structure that was preliminary designed using closely stiffened shell structure has been identified for study. This is a cylindrical structure having a diameter of 4.0m and a height of 2.75m which should safely withstand the loads expected on it during different phases of flight. It should safely carry the accessories needed for the next stage separation. A detailed design analysis of this particular launch vehicle structure using integrally stiffened construction is done both theoretically and also the results are verified by using FEA packages. The scope of study is to make a detailed design through FE analysis.

45-52

Authors: G. Brindha

Multi Carrier Code Division Multiple Access (MC-CDMA) is an attractive choice for high speed wireless communication as it avoids the problem of Inter Symbol Interference (ISI) and also exploits frequency diversity. In order to support multiple users with high speed data communications, the MC-CDMA technique is used to address these challenges. MC-CDMA experiences severe multipath fading which badly affects its performance. When transmission over fading channel multi-cell interference occurs and this degrades the performance of the system. This paper specially analyzes the BER performance under Rayleigh fading channel conditions of MC-CDMA in presence of AWGN (Additive White Gaussian Noise) using BPSK modulation for different number of subcarrier, different number of users using MATLAB program, and finally the paper also presents a comparison between simulated results, which shows the reduction in BER performance.