By combining ab initio quantum mechanics calculation and Drude model, electron temperature and lattice temperature dependent electron thermal conductivity is calculated and implemented into a multiscale model of laser material interaction, which couples the classical molecular dynamics and two-temperature model. The results indicated that the electron thermal conductivity obtained from ab initi...

The improvement of electrical conductivity of carbon-fiber reinforced plastics (CFRP) has been investigated by conductive silver nano-particles coating for the purpose of aircraft lightning protection. Silver nano-particles in colloid were sprayed on the surface of carbon fibers, which were then impregnated by epoxy resin to form a CFRP specimen. Electrical resistance was measured by contact re...

A combined experimental and theoretical investigation was conducted to examine the thermal conductivity of layers of wire mesh screen. Employing a carefully controlled sintering process, layers of sintered wire screen were examined experimentally. The experimental results indicate that the effective thermal conductivity in the z-direction (i.e., normal to the plane of the wire screen layers) fo...

Because of the large surface-to-volume ratio, the conductivity of semiconductor nanostructures is very sensitive to surface chemical and structural conditions. Two surface modifications, vacuum hydrogenation (VH) and hydrofluoric acid (HF) cleaning, of silicon nanomembranes (SiNMs) that nominally have the same effect, the hydrogen termination of the surface, are compared. The sheet resistance o...

Changes in electrical as well as surface composition such as chemical and electronic properties of Mg-doped p-type GaN by phosphorus implanting are systematically investigated using Hall effect and X-ray photoelectron spectroscopy (XPS) measurements. It is shown that p-type conductivity of Mg-doped GaN can be improved by implanting P atoms after a proper post-implantation annealing treatment, p...

We show that certain three-dimensional (3D) superlattice nanostructure based on Bi2Te3 topological insulator thin films has better thermoelectric performance than two-dimensional (2D) thin films. The 3D superlattice shows a predicted peak value of ZT of approximately 6 for gapped surface states at room temperature and retains a high figure of merit ZT of approximately 2.5 for gapless surface st...

Dissipation of charges built up near the surface of insulators due to space environment interaction is central to understanding spacecraft charging. Conductivity of insulating materials is key to determine how accumulated charge will distribute across the spacecraft and how rapidly charge imbalance will dissipate. To understand these processes requires knowledge of how charge is deposited withi...

approved: ______________________________________________________ Jonathan Istok Estimating the hydraulic conductivity of earth materials is important for many water resource modeling efforts, including predicting the transport of pollutants in ground water, computing surface runoff for flood control, and computing water budgets. This research implicitly used topography, soil, and climate data t...

Low solar absorptivity, space environmentally stable polymeric materials possessing sufficient electrical conductivity for electrostatic charge dissipation (ESD) are of interest for potential applications on spacecraft as thin film membranes on antennas, solar sails, large lightweight space optics, and second surface mirrors. One method of imparting electrical conductivity while maintaining low...

We present a method for quantitative measurement of electrical conductivity of semiconductor wafers in a contactless fashion by using millimeter waves. A focusing sensor was developed to focus a 110 GHz millimeter wave beam on the surface of a silicon wafer. The amplitude and the phase of the reflection coefficient of the millimeter wave signal were measured by which electrical conductivity of ...