Investigations on the Effect of Ball Burnishing Parameters on Surface Roughness and Corrosion Resistance of Hsla Dual - Phase Steels

Surface finish has a vital influence on most functional properties of a component, such as fatigue strength, wear resistance and corrosion resistance. This has led to processes such as lapping, honing, and burnishing. Burnishing is a fine finishing operation involving the cold working and plastic deformation of surface layers to enhance the surface integrity and the functional utility of a component. This study has been carried out to establish the effect of burnishing parameters, i.e. feed rate, speed, force, ball diameter and lubricant on surface roughness and corrosion resistance of HSLA dual – phase steel specimens. The result indicates that burnishing parameters have a significant effect on surface roughness and corrosion resistance

EVALUATION OF MEAN PEAK EXPIRATORY FLOW RATE (PEFR) OF HEALTHY CHILDREN BELONGING TO URBAN AREAS OF HYDERABAD

Introduction: Peak Expiratory flow rate (PEFR) is an important measure of lung function in obstructive airwaydiseases. The values of PEFR vary with ethnicity and geographical areas as well as age, sex and height. Bronchialasthma is a common entity in childhood respiratory illness but unlike adults regional data regarding PEFR is missingwith very few studies done in Hyderabad. Thus this study was designed to determine PEFR in urban children ofHyderabad and correlate it with their age, sex and height. Materials and methods: 2200 children of age 8-18months were subjected to PEFR measurement and their anthropometry was recorded. PEFR measurement wasdone using wright’s peak flow meter for three times and best of this was recorded. This was correlated with age,weight and height in both sexes. Results: PEFR increased with age, weight and height in both sexes.it was higher inboys when compare to girls. Correlation was best with height and so nomograms for PEFR based on the height weredesigned. Conclusion: Regional PEFR standard values need to be determine area wise. Larger studies needed tocheck the accuracy of PEFR –height nomogram design