Title of Document: DEVELOPMENT OF AN ADVANCED HEAT EXCHANGER MODEL FOR STEADY STATE AND FROSTING CONDITIONS Varun Singh Doctor of Philosophy, 2009 Directed By: Reinhard Radermacher, Professor Department of Mechanical Engineering Air-to-refrigerant fin-and-tube heat exchangers are a key component in the heating, air conditioning and refrigeration industry. Considering their dominance, the indust...

A major objective of the theory of defects is to relate the mechanical behaviour of macroscopic materials to the spatio-temporal evolution of the microstructure. The present paper deals with the dislocation-dynamical foundations of plastic instabilities and the propagation of slip in coherent plastic deformation modes (solitary plastic waves). Solitary waves arise from a proper balance between ...

Vibrothermography is a promising technique that uses elastic ultrasonic wave excitation in solids for quality maintenance, e.g. in aerospace and automotive industry to monitor the integrity of surface or subsurface features. Vibrothermography allows for defect selective imaging using thermal waves that are generated by elastic sound or ultrasound waves. The mechanism involved is local friction ...

Micro/nanostructures have been extensively studied to amplify the intrinsic wettability of materials to create superhydrophilic or superhydrophobic surfaces. Such extreme wetting properties can influence the heat transfer performance during phase-change which is of great importance in a wide range of applications including thermal management, building environment, water harvesting and power pro...

6AP and GA are potent inhibitors of yeast and mammalian prions and also specific inhibitors of PFAR, the protein-folding activity borne by domain V of the large rRNA of the large subunit of the ribosome. We therefore explored the link between PFAR and yeast prion [PSI(+)] using both PFAR-enriched mutants and site-directed methylation. We demonstrate that PFAR is involved in propagation and de n...

Nonlinear acoustic wave propagation equation with void fraction (volume fraction of gas phase) is derived and numerically solved for the simulation of HIFU (High Intensity Focused Ultrasound) with micorbubbles in the present paper. HIFU is one of promising treatments for cancer. The focused pressure waves generate heat and necrose cancer cells. It has been lately reported that the existence of ...

We consider nonlinear heat conduction satisfying a variational principle of Fermat type in the case of stationary heat ̄ow. We review origins of a physical theory and transform it into a formalism consistent with irreversible thermodynamics, where the theory emerges as a consequence of the theorem of minimum entropy production. Applications of functional equations and the Hamilton±Bellman±Jacob...

We present neutron diffraction, magnetic susceptibility and specific heat data for a single-crystal sample of the cubic Cu3Au structure compound Pr3In. Antiferromagnetic order occurs below TN=12 K with propagation vector 0,0 ,0.5± where 1/12. The neutron diffraction results can be approximated with a model where the moments in each of the three Pr sublattices form ferromagnetic sheets perpendic...

Autoigntion and front propagation behavior in Low Temperature Combustion (LTC) engine environments is investigated in this paper. First, non-reacting 3D engine simulations are conducted to investigate different mixture formation scenarios that might exist in LTC engines prior to autoignition. It is found that depending on the timing of fuel spray injection and the level of wall heat loss, two d...

Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with log...