Abstract This work investigates the phase transformations in silica (SiO 2 ) during heating to a target temperature between 1700 °C and 1900 effect of SiO polymorphs on reduction reaction 2SiO + SiC = 3SiO CO silicon production. Different rates up have been used achieve different compositions quartz, amorphous cristobalite. The had minor final composition, longer time at temperatures > 1400 ...

We investigate the role of non-isothermality in gravitational collapse and protostellar accretion by explicitly including the effects of molecular radiative cooling, gas-dust energy transfer, and cosmic ray heating in models of spherical hydrodynamic collapse. Isothermal models have previously shown an initial decline in the mass accretion rate Ṁ during the accretion phase of protostellar evolu...

This thesis presents experimental work performed to develop a sensitive screening test procedure for biomass pellets, using isothermal calorimetry for direct measurement of the heat production rate. This method can be used to directly compare the reactivity, that is how prone the fuel is to self-heating, of different batches of biomass pellets. The results could be used for safety assessment by...

The conversion and utilization of biomass as an alternative source of energy have been subjects of interest in various countries, but technical barriers to the technology and design of conversion plants have considerably impeded the development and use of alternative power sources. Theoretical studies on the conversion process enhance our understanding of the thermochemical conversion of solid ...

Mode conversion in the region where the sound and Alfvén speeds are equal is a complex process, which has been studied both analytically and numerically, and has been seen in observations. In order to further the understanding of this process we set up a simple, onedimensional model, and examine wave propagation through this system using a combination of analytical and numerical techniques. Sim...

The crystallization kinetics of an Al89La6Ni5 amorphous alloy were studied by thermal analysis. Both continuous heating and isothermal DSC traces showed that the Al89La6Ni5 amorphous alloy undergoes a two-stage crystallization process upon heating. The ®rst transformation, in which fcc-Al precipitates from the amorphous matrix, is a nucleation and three-dimensional di€usion-controlled growth pr...

For non-isothermal operation in plate type gas absorber, the temperature changes and number of ideal trays can be determined with recourse to graphical method. In this paper there is an analysis illustrating that a Modified Kremser Equation can be used for plate type gas absorber in non-isothermal operation.

Isothermal model used in current computational fluid dynamic (CFD) model neglect the internal heat transfer during biomass devolatilization. This assumption is not reasonable for thermally-thick particles. To solve this issue, a heat transfer corrected isothermal model is introduced. In this model, two heat transfer corrected coefficients: HT-correction of heat transfer and HR-correction of rea...

A numerical model of a steady state, thin and isothermal accretion disk is presented. We demonstrate that 'zero torque' inner boundary condition is a reasonable approximation provided that the disk thickness, including the thickness of the torquing magnetic fields, is small. It is likely that this conclusion is correct also for non-isothermal and non-steady disks, as long as the total thickness...