Sökning: "rapid and slow expansion"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden rapid and slow expansion.
1. Railway wheel steel behaviour upon thermo-mechanical loadings
Sammanfattning : Optimised railway maintenance techniques such as rail grinding and milling, or rail repair welding, are vital to more sustainable rail networks. As demands on the railway increases, the need to better understand the material behaviour during local heating events occurring during maintenance is amplified. LÄS MER
2. Degradation of rock and shotcrete due to ice pressure and frost shattering
Sammanfattning : In recent years the Swedish Rail Administration has observed an increased incidence of shotcrete and rock fall-outs in its tunnels, for which reason it has initiated several research projects, of which the present project entitled "Degradation of rock and shotcrete due to ice pressure and frost shattering" is one. The aim of this licentiate project was to bring together experience and information relating to ice formation and the effect of ice pressure on fault zones, cracks and, in particular, the shotcrete/rock interface. LÄS MER
3. Hygro- and hydroexpansion of paper : Influence of fibre-joint formation and fibre sorptivity
Sammanfattning : Paper is a versatile, cheap and environment-friendly material. Nevertheless, there are several factors limiting its usefulness, and one of the major issues is that cellulosic and ligno-cellulosic fibres spontaneously sorb water. At the same time, the water uptake changes the dimensions of the paper. LÄS MER
4. Aspects of fluid therapy in the critically ill. Experimental and clinical studies on fluid therapy in the inflammatory conditions
Sammanfattning : Patients suffering from inflammatory conditions often present with severe hypovolemia due to vasodilatation and increased vascular permeability. Early administration of fluids is, therefore, a cornerstone and lifesaving therapy.However, a vigorous and aggressive fluid therapy increases tissue edema, worsen tissue perfusion and organ function. LÄS MER
5. Modelling of cyclic and viscous behaviour of thermomechanically loaded pearlitic steels; Application to tread braked railway wheels
Sammanfattning : In service, railway wheel and rail materials are subjected to high stresses and, in some cases, elevated temperatures. The high stresses are caused by the rolling contact between wheel and rail. Furthermore, heat generated from tread braking and/or sliding between wheel and rail gives additional stress due to constrained thermal expansion. LÄS MER