Sharif Digital Repository

The chemical modification of isotactic polypropylene was performed by the free-radical-promoted grafting of 1,1,1-trimethylolpropane trimethacrylate (TMPTMA) in the presence of dicumyl peroxide (DCP) as the initiator. The reaction was carried out both in a batch internal mixer and in a corotating twin-screw extruder; the effects of the peroxide and monomer concentrations on the extent of modification in terms of the grafting efficiency and polymer chain structure variations were investigated. The modified samples were characterized with Fourier transform infrared to determine the structure of the grafted groups and the degree of functionalization, with gel permeation chromatography and the... 

Current design practice is usually to produce a safety system which meets a target level of performance that is deemed acceptable by the regulators. Safety systems are designed to prevent or alleviate the consequences of potentially hazardous events. In many modern industries the failure of such systems can lead to whole system breakdown. In reliability analysis of complex systems involving multiple components, it is assumed that the components have different failure rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed generating function (GF) and the recursive algorithm to obtain reliability of systems consisting of a... 

Current design practice is usually to produce a safety system which meets a target level of performance that is deemed acceptable by the regulators. Safety systems are designed to prevent or alleviate the consequences of potentially hazardous events. In many modern industries the failure of such systems can lead to whole system breakdown. In reliability analysis of complex systems involving multiple components, it is assumed that the components have different failure rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed generating function (GF) and the recursive algorithm to obtain reliability of systems consisting of a...