International Journal of Research in Science & Technology

Number 11, 2014

5
Integration of Litho-Units Derived From Satellite Data

Authors: Dr. A. Subhash Babu , Dr.G. Udaya Laxmi and Dr. G. Ramadass

Abstract

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Remote sensing techniques were applied to demarcate lithological and structural features of the area around Mahabubnagar district of Telangana and parts of Gulburga district of Karnataka of eastern Dharwr craton Through Spectral Geological techniques like False Color Composition (FCC)/ Band Combination, Band Indices/ Band Ratios, Principle Component Analysis (PCA), Minimum Noise Factor (MNF), Spectral Curve Matching – mainly to identify MgOH rich soils, which are weathered from kimberlites, Spectral Angle Mapper (SAM), End-Member identification etc. are used to discriminate the lithology of the study area using LANDSAT 8 and ASTER VNIR, SWIR and TIR wavelengths. Surface structures, which could be probable subsurface indicators of faults, intersections of these are main source of kimberlite emplacement are also identified with various techniques, these are penetrated into deep-seated.

5
Implementation of Windowing Technique for Minimizing the Side Lobes in Antenna Array Design

Authors: Sk. Khadar Basha and Sk. Abdul Rehman

Abstract

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Number of views: 306

The objective of this project is to generate the radiation pattern of linear arrays like broad side array and end fire array by reducing the side lobes. This project is implemented by using MATLAB. For some applications, single element antennas are unable to meet the gain or radiation pattern requirements so combining several single antenna elements in an array can be a possible solution. Array is a system of similar antennas oriented similarly to get greater directivity in a desire direction. Various techniques can be used to reduce the side lobes in the radiation pattern. Here, we employ windowing techniques for the reduction of side lobes. The 4-term Blackman-Harris window function is a good general purpose window, having side lobe rejection in the high 90s dB and having a moderately wide main lobe. The Kaiser-Bessel window function has a variable parameter, beta, which trades off side lobes for main lobe. It compares roughly to the Blackman-Harris window functions, but for the same main lobe width, the near side lobes tend to be higher, but the further-outside side lobes are low. Antennas exhibit a specific radiation pattern. Tapering of side lobes in the radiation pattern has several advantages and applications. These have wide importance in specific military applications. Military antennas are designed to have a narrow main beam as reasonable to give higher resolution and the lowest side lobes possible to reject echoes and jamming at other elevation angles. Radar was first developed for military purposes. The early surveillance radars often used a line feed and a cylindrical reflector. The radiation pattern from the line feed was shaped to provide lower side lobes and a slightly broader main beam with slightly less gain.

6
Experimental Investigation on Hybrid Steel Fiber Reinforced Concrete Beam – Column Joints Under Cyclic Loading

Authors: J.Devi Keerthana and Ch.Surendra Reddy

Abstract

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Number of views: 291

An investigation on the performance of reinforced concrete beam column joints under cyclic loading is reported. Joints have been cast with adequate and deficient shear capacity and bond of reinforcements at the beam column joint. Steel Fiber Reinforced like crimped hook end have been applied on the joints in different volume fraction and aspect ratios. The column subjected to an axial force while the beams are subjected to cyclic load with controlled displacement. The displacement is increased monotonically using a hydraulic push and pull jack. The hysteretic curves of the specimen have been plotted. The energy dissipation capacity of retrofitted beam column joints with various hybrid steel fibres configurations has been compared. The results show that the strengthened beam column joint exhibit increased strength, stiffness, energy dissipation and composite action until failure.

6
Performance Evaluation and Cost Analysis of Selected Shielded Manual Metal Arc Welding (SMMAW) Steel Electrodes

Authors: B.O. Afolabi, T.A. Adegbulugbe and A.O.D. Adejumo

Abstract

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The work investigated the effect of electrodes on consumption rate and mechanical behavior of welded mild-steel and galvanized-steel joints, to ascertain their performance level under service conditions, which has increased joint failure and increased equipment cost of maintenance. 20 welded mild-steel and galvanized-steel flat bars (¾” x ¼ “) produced from shielded manual metal arc welding (SMMAW) were prepared using mild steel electrodes, gauge 12 of four selected different brands from local hardware market. Standard methods were applied for tensile properties using Ultimate tensile test machine. Also, the consumption rate of each brand of electrode in joining specified metal types were ascertained through 5 replications within specified time frame (6 seconds) for each metal type. Results obtained from tensile tests in respect to allowable maximum load, breaking point and yield point. The result showed allowable maximum load at tensile strength of 5524.767 N and 5131.088N attained for mild steel welded with Zika electrode and galvanized steel welded with Oerlikon electrode respectively. Changes were noticed in the modulus of elasticity at yield point for galvanized steel welded with Fed electrode, and mild steel welded with China electrode. The consumption rate with equivalent price value was projected to 8 working hours, this gave maximum consumption rate of 528.4 sticks of electrodes (2.11 packs), corresponded to price value of 4,227naira in respect to galvanized steel welded with Zika. It was therefore recommended that Zika electrode brand are in no-way fit to be used on galvanized steel based on tensile properties test and consumption rate. Zika electrode brand is most suitable for mild steel joints for tensile properties, while Oerlikon electrode brand is best suited for galvanized steel joints when the same property is desired. All specified electrode brands are found to be more cost effective when used on mild steel compared to galvanized steel.

8
Experimental Studies on Retrofitting of RCC Beams Using GFRP

Authors: Md.Vazeer Ahmed and Ch.Surendra Reddy

Abstract

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Number of views: 281

The studies conducted on the retrofitting of RCC beams using GFRP are limited. So it is essential to study the shear carrying capacity, flexural carrying capacity and ductility of flexural deficient beams by retrofitting with GFRP. u wrapping technique was adopted for both shear deficient beams and flexural deficient beams. The number of layers of GFRP was considered as variable. The effect of increasing the number of layers of GFRP has been studied. In this work retrofitting of RCC beam of shear deficient beam and flexural deficient beam and flexural deficient beam using GFRP lamination will be studies. Fourteen beams of size 100mm*150mm*1200mm were cast. Out of this two control beam one was used as shear deficient beam and another was used as flexural deficient beam . remaining twelve beams six beams were shear deficient used for retrofitting and six beams were flexural deficient used for retrofitting. Shear deficient control beam (SDCB) and flexural deficient control beams (FDCB) were loaded upto ultimate load in the compression testing machine of 300 tones capacity. Shear deficient and and flexural deficient beams were retrofitting using GFRP which was bonded with epoxy resin.. load deflection behavior of beam, retrofitting with different layers of stitched mat and woven roving was compared. Study of ductility of flexural deficient beams was made.