Bøger af Dr Deepak Kumar

The central problem addressed is how when an emulsion is used as a lubricant, an oil droplet may be brought to steel substrate to provide microhydrodynamic lubrication. This happens by disjoining a thin water film adhered to steel substrate separating oil from substrate. Quantum mechanical and thermodynamic insights are considered to build a model. The model may be manipulated by selection surfactants and substrates of different chemical potentials to create situations, which enable the disjoining of water film. Different types of forces using atomic force microscopy and physic-chemical methods to validate the model and come to the conclusion, that for a given chemical potential only when the droplet size is controlled by surfactant chemistry and concentration to remain below a critical size it is possible to create a strongly attractive regime between the oil and the steel to bring about the disjoining process. The author demonstrates experimentally for a range of substrates, surfactants and their concentrations in the media, that there is a combination, as suggested by his theoretical model, for which the coefficient friction, in steel on steel sliding experiment, is optimum.

Software Reliability Engineering quantifies the software failures. Software failures may be due to errors, ambiguities, oversights or misinterpretation in the Software Development. Thus the reliability of software is compromised by system failures. The Software Reliability Growth Model (SRGM) is a tool, which can be used to evaluate the software quantitatively, develop test status, schedule status and monitor the changes in reliability performance. Software Reliability models have been developed to estimate the fault content, failure rate and fault removal rate per fault in software and to predict the reliability of the software at the release time.