Photoacoustic (or more precisely, photothermoacoustic) signals are generated by the absorption of photons, expressed as acoustic waves, and can be related to the incident laser fluence rate. Here a calibration procedure for frequency domain (FD) photoacoustics is presented which utilizes the relatio...

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...

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...

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...

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...

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...

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...

Frequency-domain correlation and spectral analysis photothermoacoustic (FD-PTA) imaging is a promising new technique, which is being developed to detect tumor masses in turbid biological tissue. Unlike conventional biomedical photoacoustics which uses time-of-flight acoustic information induced by a...

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...

In this study, we employ the discontinuous molecular dynamics simulation method to investigate the collapse properties of a single heteropolymer chain in an explicit solvent. Solvent density ρ, fraction of hydrophobic monomers n H (defined as the ratio of the number of hydrophobic monomers to the t...

This thesis is concerned with the orientational and conformational behaviour of molecules partially oriented in a nematic liquid crystal. We have studied these systems experimentally using Multiple-Quantum NMR spectroscopy, and computationally using the Monte Carlo simulation method. An important go...

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 ...

Interstitial fiber-optic-based approaches used in both diagnostic and therapeutic applications rely on localized light-tissue interactions. We present an optical technique to identify spectrally and spatially specific exogenous chromophores in highly scattering turbid media. Point radiance spectrosc...

We have used Brownian dynamics simulations to study the dynamics of a bead-and-spring polymer subject to a flashing ratchet potential. To elucidate the role of hydrodynamic (HD) interactions, simulations were carried out for the cases where HD interactions are present and when they are absent. The a...