Herein we study the following problem: Suppose we are given a supply of grains, which are of the same material and have equal volume. Given a finite set of material tensors (i), can we find an arrangement of grains in an aggregate so that all the tensors (i) pertaining to this aggregate are isotropic? In this paper we examine the preceding problem within the special context of physical theories...

We report the first detailed study of the kinetics of dispersion of nanoparticles in thin polymer films using temperature dependent in situ X-ray scattering measurements. We show a comparably enhanced dispersion at higher temperatures for systems which are otherwise phase segregated at room temperature. Detailed analysis of the time dependent X-ray reflectivity and diffuse scattering data allow...

AD Axial diffusivity ADC Apparent diffusion coefficient ADHD Attention deficit hyperactivity disorder BET Brain extraction tool CSF Cerebrospinal fluid DKI Diffusion kurtosis imaging DTI Diffusion tensor imaging DWI Diffusion-weighted imaging FA Fractional anisotropy MD Trace, mean diffusivity MRI Magnetic resonance imaging RD Radial diffusivity ROI Region of interest TBSS Tract-based spatial s...

A three-parameter model based on the Whittle-Matérn correlation family is used to describe continuous random refractive-index fluctuations. The differential scattering cross section is derived from the index correlation function using nonscalar scattering formulas within the Born approximation. Parameters such as scattering coefficient, anisotropy factor, and spectral dependence are derived fro...

We use fractal continuous random media to model visible and near-infrared light scattering by biological tissue and cell suspensions. The power law of the reduced scattering coefficient, the anisotropy factor of scattering, and the phase function are derived with good agreement with experimental results. Implications for spectroscopic tissue diagnosis are discussed.

BACKGROUND AND PURPOSE Cerebral ischemia leads to a rapid decrease of the apparent diffusion coefficient. For fractional anisotropy both increase and decrease have been reported in acute ischemic stroke. Aim of this study was to characterize early water diffusion changes in a homogenous group of acute stroke patients and to clarify the issue of early fractional anisotropy changes and their rela...

Due to their aesthetic value and high compressive strength, dentists have recently employed ceramics for restoration materials. Among the ceramic materials, zirconia provides high toughness and crack resistant characteristics. Residual stresses develop in processing due to factors including grain anisotropy and thermal coefficient mismatch. In the present study, polychromatic X-ray (Laue) micro...

Manuscript received November 5, 1998. Manuscript revised January 8, 1999. † The authors are with Niigata University, Niigata-shi, 9502181 Japan. †† The author is with University of Illinois at Chicago, IL, 60607-7018, USA. * Presently, with Fujitsu System Integration Laboratories Ltd. ** Presently, with NEC Saitama Corp. SUMMARY This paper discusses the classification of targets buried in the u...

a 36-year-old woman, diagnosed with systemic lupus erythematosus (sle), showed bulbar symptoms including impaired memory, slurred speech and swallowing difficulty 7 days before admission. magnetic resonance imaging (mri) showed symmetric confluent hyperintensities in the bilateral cerebral white matter on t2 weighted imaging (t2-wi), extended into the genu of the internal capsule and the crus c...

Ultrasonic backscattering measurements by means of spatial averaging technique were carried out in steel to determine the ultrasonic attenuation coefficient. The attenuation coefficients were evaluated from the exponential decay of the backscattering signal. The results were compared with those obtained by evaluating the amplitude decay of the main pulse. Good agreement is observed provided the...