three types of vehicles, pride, peugeot 405 glx and paykan were tested from the point of view of exhaust emissions (co, hc, nox) and fuel consumption, on chassis dynamometer running european standard driving cycle with three kinds of fuels, mtbe free unleaded regular gasoline (urg) as base fuel and 10 and 15 volume percent mtbe –gasoline blends as comparable fuels. utilizing mtbe blended fuels ...

springs are the  mechanical parts which have many application in industries. static and dynamic forces cause relaxation in these parts so that they lose some of their free length and reaction force. springs constant are very important in airplane and vailway industry since constant and variable forces are applied to them in period time, therefore it is necessary to avoid decreasing in spring co...

the oil-paper insulation is a type of an inexpensive combination insulation system in oil-filled power transformers. in this study the dielectric and strength properties of canola oil and mineral oil impregnated hand-sheet papers were investigated. all hand sheets were made of unbleached bagasse soda pulp with two different freeness levels of 200 ± 25 ml, csf and 400± 25 ml,csf. after drying th...

Estimation of the height of caved and fractured zones above a longwall panel along with the stability conditions of the goaf area are very crucial to determine the abutment stresses, ground subsidence, and face support as well as designing the surrounding gates and intervening pillars. In this work, the height of caving-fracturing zone above the mined panel is considered as the height of destre...

geometrical profile (roughness) of joint surfaces influences the behaviour of rock joints under shear loading. with regard to the dilation, there are two models of direct shear test that may simulate the original loading condition existing in the location from where the specimens have been sampled. the first model in which the normal load is constant (cnl) and the discontinuity is free to dilat...