Informatics Publishing Limited

N. Mohan Rao ¹, P. K. Kulkarni ¹, S. K. Kashyap ¹

Affiliations
1 National Institute of Occupational Health (ICMR), Meghaninagar, Ahmedabad-380016, IN

Abstract

Nutrition plays an important role in the growth and development of the lungs and may also reflect on pulmonary function values. The growth charts and curves derived from high school children of high social class was found to be different from those taken from the children of lower class in an economically backward country. The growing appreciation of the important role played by the respiratory muscles in the pathophysiology of pulmonary diseases suggests that nutrttional status is an important determinant of respiratory muscle structure and function.

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Koruprolu Raghubabu ¹, N. Mohan Rao ¹, Buridi Kalyana Ramu ², C. Ramdas ³

Affiliations
1 Department of Engineering Chemistry, AU College of Engineering (A), Andhra University, Visakhapatnam-530003, AP, IN
2 Department of Chemistry, Maharaja's College (Aided & Autonomous), Vizianagaram-535002, AP, IN
3 M/S Tychy Industries, R&D Division, Hyderabad (AP), IN

Abstract

Three direct, simple and sensitive visible spectrophotometric methods (M1,M2 and M3) are described for the assay of Racecadotril in pure and solid dosage forms. The method M1 is based on the formation of colored molecular complex with sodium nitroprusside in presence of acetaldehyde under alkaline conditions and exhibits λ max at 560nm. The method M2 involves oxidative coupling of drug with brucine in presence of sodium meta periodate and purple red colored species is formed and exhibits absorption maxima at 520nm. The method M3 is based on the formation of yellowish brown colored species by the drug with Folin reagent and exhibits absorption maxima at 450nm.Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges (8.0-40) μg/ml for methods M1, M2 and (20-60) μg/ml for method M3 respectively. The proposed methods are applied to commercial available formulations and the results are statistically compared with those obtained by the reported UV reference method (in methanol, λ max at 231nm) and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the Racecadotril in the presence of other ingredients that are usually present in dosage forms.

Keywords

Inner Molecular complex, Aromatic Nucleophillic substitution, Oxidative coupling, Statistical analysis, Regression equation.

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M. Bala Chennaiah ¹, P. Nanda Kumar ², G. Ranga Janardhana ³, N. Mohan Rao ³, D. Hema ⁴

Affiliations
1 Mech. Engg., Dept., V R Siddhartha Engineering College, Vijayawada, IN
2 Narayanadri Institute of Science and Technology, Rajampet, Kadapa, IN
3 JNTU, College of Engg., Kakinada, IN
4 Sree Potti Sriramulu Chalavadi Mallikarjun Rao College of Engg. & Technology, Vijayawada, IN

Abstract

Finite Element Analysis (FEA) has become a practical method of predicting stresses and deflection for loaded structures. EEA accurately identifies the load path, which can he difficult using Classical Analysis with complex structures. EEA shell element models are effective for predicting loads in weldments fabricated from plate, sheets, structural shapes and tube. The formulation used for a finite element shell model is that of full penetration welds at every joint. Here a method to derive the loads at weld joint from stress results of FEA shell element model is presented. Apart from these loads, twisting moments is also introduced and twisting load is calculated. Hence the total effect of all these loads is considered. The weld loads, weld throat size requirements are calculated using classical methods. The FEA arid Classical method results are compared and the importance of FEA is justified.

Keywords

Weld Load, Weld Throat, Finite Element Analysis, Shell Element Model, Classical Analysis.

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D. V. A. Rama Sastry ¹, K. V. Ramana ², N. Mohan Rao ³, M. Phani Kumar ², V. S. S. Rama Chandra Reddy ²

Affiliations
1 Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, Andhra Pradesh, IN
2 Dept. of Mech. Engg., Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, Andhra Pradesh, IN
3 Dept. of Mech. Engg., University College of Engg., JNTUK University, Kakinada, Andhra Pradesh, IN

Abstract

Exposure of human body to vehicular vibrations in transit may lead to the human discomfort. Ride comfort is one of the major issues in design of automobiles. Magneto rheological (MR) dampers are emerging as most feasible solution for various applications in controlling vibrations. An MR damper is a semi-active device, which will offer the advantages of both active and passive suspension. In this study, the MR damper based semi-active suspension system for a car is analysed for ride comfort of 7 degrees of freedom model human body lumped mass, considering head, upper torso, lower torso and pelvis, seated over a seat of a quarter car model and is compared with that of similar system using passive damper. A MR damper is fabricated and is filled with MR fluid made of Carbonyl iron powder and Silicone oil added with additive. Modified Bouc-Wen Model developed by Spencer is used to model the behaviour of MR damper. All the parameters of this model are identified using data acquired from experiments conducted to characterise MR damper. Further, using the Spencer model of MR damper, the human body seated over quarter car is simulated by implementing a semi-active suspension system for analysing the resulting displacement and acceleration of the human body. The ride comfort performance of vehicle model with passive suspension system is compared with corresponding semi-active suspension system. The simulation and analysis are carried out using MATLAB/SIMULINK.

Keywords

Magneto Rheological Dampers, Quarter Car Model, Suspension Systems, Spencer Model, Human Body Vibrations.

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D. V. A. Rama Sastry ¹, K. V. Ramana ¹, N. Mohan Rao ²

Affiliations
1 Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, Andhra Pradesh, IN
2 University College of Engg., JNTUK University, Kakinada, Andhra Pradesh, IN

Abstract

Ride comfort and vehicle handling are the two major issues to be dealt in the design of suspension systems of automobiles. With passive systems offering contrariety on these two parameters, the alternative systems are being in study. Magnetorheological (MR) damper, a most feasible semi-active device, is one such alternative, which will offer the advantage of dealing with both these issues overcoming contrariety. In this study, the suspension system of a car using MR damper is analysed at 5 different currents viz., 0A, 0.25A, 0.5A, 0.75A, 1A, using 2DOF quarter car model and 4DOF half car models for ride comfort and handling and the comparisons of these are done with same suspension system equipped with regular passive damper. A MR damper is built-up using MR fluid consisting of carbonyl iron powder and silicone oil added with additive. Further, the characteristic of this damper is established by conducting experiments, which in turn is used to identify the parameters of Spencer model for MR damper. Using Spencer model of MR damper, at 5 different currents, the quarter car and half car models of vehicle suspension system are simulated by implementing a semi-active suspension system for analysing the resulting displacement and acceleration in the car body. The ride comfort and vehicle handling performance of each specific vehicle model with passive suspension system are compared with corresponding skyhook, ground hook and hybrid based semi-active suspension systems. The simulation and analysis are carried out using Matlab/Simulink.

Keywords

Magnetorheological Dampers, Semi Active Suspension Systems, Spencer Model, Skyhook, Ground Hook Hybrid Control.

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