Results

1 - 25 of 140
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Previous work on thermally induced arsenic deactivation in highly doped silicon has proven the generation bf vacancies and suggests the formation of arsenic-vacancy clusters as the deactivation mechanism. Using positron annihilation spectroscopy in the two-detector coincidence geometry, we are able ...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Motivated by a recent report by Dickey et al. [Phys. Med. Biol. 46, 2359 (2001)], who demonstrated optical property retrieval by using relative radiance measurements at a single position, we investigate the uniqueness of relative radiance measurements for quantifying the optical properties of turbid...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Background and Objectives: Fluoroptic sensors are used to measure interstitial temperatures but their utility for monitoring laser interstitial thermal therapy (LITT) is unclear because these sensors exhibit a measurement artefact when exposed to the near-infrared (NIR) treatment light. This study i...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The interferometric measurement of laser induced thermoelastic expansion of tissue samples can be used to estimate their optical, thermal and mechanical properties. This method was used to assess the Gruneisen coefficient and optical attenuation depth for native and coagulated ex-vivo bovine liver a...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
A density-functional theory of the isotropic-nematic phase transition in both rigid and semiflexible hard-sphere chain fluids is described. The theory is based on an exact analytical evaluation of the excluded volume and second virial coefficient B-2 for rigid chain molecules, which demonstrates tha...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
We employ Molecular Dynamics simulations to study the phase behavior and equilibrium dynamics of a fully flexible Lennard-Jones chain immersed in a Lennard-Jones solvent at high solvent densities. The hydrophobicity of the model polymer is adjusted by varying the attractive component of either the m...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
A polycrystalline sample of Al63Cu25Fe12 has been studied as a function of thermal treatment by positron annihilation and X-ray diffraction techniques. Results suggest the presence of an icosahedral-to-rhombohedral microcrystalline phase transition near 300-degrees-C. Below this transition, a large ...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
We analyze the finite-size corrections to the free energy of crystals with a fixed center of mass. When we explicitly correct for the leading (ln N/N) corrections, the remaining free energy is found to depend linearly on 1/N. Extrapolating to the thermodynamic limit (N -->infinity), we estimate t...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Interstitial quantification of the optical properties of tissue is important in biomedicine for both treatment planning of minimally invasive laser therapies and optical spectroscopic characterization of tissues, for example, prostate cancer. In a previous study, we analyzed a method first demonstra...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Samples of the stable Al75Pd15Fe10 decagonal quasicrystal have been studied both in the as-cast state and after annealing. Structural properties were investigated using X-ray diffraction and Fe-57 Mossbauer effect studies. X-ray patterns show that annealing improves the degree of order in the decago...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The coil-globule transition of a polymer in a solvent has been studied using Monte Carlo simulations of a single chain subject to intramolecular interactions as well as a solvent-mediated effective potential. This solvation potential was calculated using several different theoretical approaches for ...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Amorphous Al-Y-Ni alloys, prepared by rapid solidification from the melt, have shown a unique combination of low density and high tensile strength. In the present work amorphous alloys of the composition Al87Y8Ni5-xFex (2 less-than-or-equal-to x less-than-or-equal-to 5) have been studied using room ...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Al-Cu-Fe alloys of several different stoichiometries have been prepared using a variety of sample preparation methods and have been studied using Fe-57 Mossbauer effect spectroscopy. Well ordered icosahedral, phason disordered icosahedral and rhombohedral crystalline phases were investigated. The re...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Multipoint optical fluence measurements can potentially be used to detect coagulation-induced changes in optical propagation during interstitial laser thermal therapy. Estimating the dimensions of coagulation using on-line optical monitoring, which is applicable to treatments where the tip of the so...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Background and Objective: Interstitial Laser Photocoagulation (ILP) is a minimally invasive cancer treatment technique, whereby optical energy from implanted optical fibers is used to therapeutically heat small, solid tumors. In this work, the potential of ILP without tissue charring is investigated...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
A Doppler broadening positron annihilation technique which allows for the study of near surface defects in bulk samples is described. The method is capable of observing changes in the homogeneous bulk defect concentration in a sample acid is also able to characterize spatially localized near-surface...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Molecular dynamics simulations are used to study the equilibrium properties and collapse dynamics of a heteropolymer in the presence of an explicit solvent in two dimensions. The system consists of a single copolymer chain composed of hydrophobic (H) and hydrophilic (P) monomers, immersed in a Lenna...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Laser thermal therapy involves heating tissue using light to temperatures between 55 °C and 95 °C for several minutes resulting in coagulation and cell death. This treatment method has been under investigation for use as a minimally invasive method for treating solid tumors and cancer cells. Heati...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Doppler-broadening positron-annihilation-spectroscopy experiment that utilizes an in situ Cu-64 source for the study of Cu and Cu-containing materials is described. This technique is particularly useful for the investigation of defect structure at elevated temperatures, and the present instrumentati...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
We present a new method for extracting the effective attenuation coefficient and the diffusion coefficient from relative spectrally resolved cw radiance measurements using the diffusion approximation. The method is validated on both simulated and experimental radiance data sets using Intralipid-1% a...