background and purpose : there has been no report in which preoperative evaluation of adc for prediction of post therapeutic outcome was presented. the aim of our study was to retrospectively evaluation the use of the apparent diffusion coefficient (adc) for the prediction of malignancy and the outcome of malignant astrocytic tumors. methods: we reviewed mri of 26 male and 14 female patients wi...

In an investigation of the mechanism responsible for the transport of water through Si02 thin films, we have performed tracer diffusion measurements involving network 0 demonstrating the importance of oxygen exchange between the Si02 network and molecularly dissolved water. We have found that in the presence of water, bound network oxygen diffuses through Si02 as a constituent of molecularly di...

Nitrogen-doped (N-doped) graphene has been prepared by a simple one-step hydrothermal approach using hexamethylenetetramine (HMTA) as single carbon and nitrogen source. In this hydrothermal process, HMTA pyrolyzes at high temperature and the N-doped graphene subsequently self-assembles on the surface of MgO particles (formed by the Mg powder reacting with H2O) during which graphene synthesis an...

The role of ammonia toxicity in the production of the hepatic coma syndrome has not been clearly defined. No direct relationship has been demonstrated consistently between arterial or venous blood ammonia-nitrogen concentration or the arteriovenous ammonia-nitrogen difference and the state of cerebral dysfunction in hepatic disease. Recently a direct relationship between an increase in blood pH...

Diffusion is interesting because it is slow. As a result, many studies of diffusion seek ways to make the process fast and selective. For example, most membrane separations use thin polymer films to recover particular chemicals. Nitrogen is separated from air, and water is purified by ultrafiltration. This is an active and important area of diffusion research. However, in other cases, we may se...

In 1979, Professor Bilger was among the first faculty to have a sabbatical visit at the new Combustion Research Facility (CRF) at Sandia Laboratories, in Livermore, California. During this sabbatical, Professor Bilger received from Dr. Mike Drake, then at General Electric Corporate Research and Development, an advance copy of the pioneering paper of Raman scattering in a turbulent flame of H2 i...

In this paper, the Diffusion Limited Cluster Aggregation (DLCA) method is employed to reconstruct the three-dimensional network of silica aerogel. Then, simulation of nitrogen adsorption at 77 K in silica aerogel is conducted by the Grand Canonical Monte Carlo (GCMC) method. To reduce the computational cost and guarantee accuracy, a continuous-discrete hybrid potential model, as well as an adso...

The work presented in this thesis started with the implementation of numerically tabulated pseudopotentials into the modelling package, AIMPRO. The algorithm scaled linearly with system size and could be incorporated efficiently into a Gaussian orbital program. Methods for modelling diffusion were then developed and were tested using a set of non-physical functions and also by looking at self d...

Oxygen contamination of a polyacrylamide gel (PAG) dosimeter can have a significant detrimental effect upon the performance characteristics of the gel as a dosimeter. Oxygen contamination can occur during preparation, but can also arise from the diffusion of atmospheric oxygen through vessel walls. Even 'trace' amounts of oxygen present in any gaseous space (usually nitrogen filled) between the...

In the thermochemical process of low-carbon steel nitridation, improvements of mechanical properties are governed by the nature (hardness, thickness, etc.) of the compound layer since the compound layer will be kept under working conditions. Because of low nitrogen diffusivity in steel and low mass transfer between gaseous reaction and steel, long duration and high temperature are classically u...