Describing functions have traditionally been used to obtain the
solutions of systems of ordinary differential equations. In this
work the describing function concept has been extended to include
nonlinear, distributed parameter partial differential equations. A
three-stage solution algorithm is presented which can be applied to
any nonlinear partial differential equation....
A mathematical model of a differential thermal analysis (DTA)
system was formulated so that influence of the various physical parameters
on the DTA peak could be determined. The specific DTA apparatus
simulated had cylindrical sample holes drilled into a nickel
block considered to have a negligible thermal resistance, and the...
We measure the thermal conductivities of nano-grained strontium titanate (ng-SrTiO₃) films deposited on sapphire substrates via time-domain thermoreflectance. The 170 nm thick oxide films of varying grain-size were prepared from a chemical solution deposition process. We find that the thermal conductivity of ng-SrTiO₃ decreases with decreasing average grain size and attribute...
The study outlined in this dissertation elucidate the thermal and structural properties of ZrB2 based ceramics as choice materials for high temperature applications. Thermal properties were investigated to improve understanding on aspects that are affected by point defects and impurities at nanoscale and electron level using a combination of lattice...
Pure aluminum deformed in torsion (shear) at elevated temperatures reaches
a broad "peak" stress and then undergoes about a 17% decrease in flow stress with
deformation to roughly 1-2 equivalent uniaxial strain. Beyond this strain the flow
stress is approximately constant. The sources for this softening are unclear. The
suggested...
In this thesis we consider boundary and initial value problems
associated with the melting of homogeneous cylinders and
spheres. The study includes the temperature distribution in cylinders
and spheres which are perfectly insulated at the surface and
subjected to a heat input respectively along the axis and at the
center....
A phase sensitive measurement technique that permits the simultaneous determination
of two independent thermal properties of thin dielectric films is presented. Applying the technique results in a film's thermal diffusivity and effusivity, from which the thermal conductivity and specific heat can be calculated. The technique involves measuring a specimen's front...
The quality of a digital image pipeline relies greatly on its color reproduction which should at a minimum handle the color constancy, and the final judgment of the excellence of the pipeline is made through subjective observations by humans.
This dissertation addresses a few topics surrounding the color processing of...