The present study is concerned with the variational principle and plane wave propagation in double porous thermoelastic infinite medium. Lord-Shulman theory [2] of thermoelasticity with one relaxation time has been used to investigate the problem. It is found that for two dimensional model, there exists four coupled longitudinal waves namely longitudinal wave (P), longitudinal thermal wave (T),...

Quantitative information on photon scattering around brachytherapy sources is needed to develop dose calculation formalisms capable of predicting dosimetric parameters with minimal empiricism. Photon absorption and scatter around brachytherapy sources can be characterized using the tissue attenuation factor, defined as the ratio of dose in water to water kerma in free space. In this study, the ...

Transversely isotropic (TI) media with the frequency-independent quality-factor elements (also called “constant- Q” transverse isotropy) are often used to describe attenuation anisotropy in sedimentary rocks. The coefficients constant- Q TI models can be conveniently defined terms of Thomsen-type attenuation-anisotropy parameters. Recent research indicates that not all those parameters for such...

objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

Low-phase-noise microwave oscillators are important to a wide range of subjects, including communications, radar and metrology. Photonic-based microwave-wave sources now provide record, close-to-carrier phase-noise performance, and compact sources using microcavities are available commercially. Photonics-based solutions address a challenging scaling problem in electronics, increasing attenuatio...

BACKGROUND Using multipollutant models to understand combined health effects of exposure to multiple pollutants is becoming more common. However, complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates from multipollutant models difficult to interpret. OBJECTIVES We aimed to quantify relationships between multiple pol...

A low-cost millimeter-wave dielectric-resonator filter using a high-order whispering-gallery mode with the coupling of curved microstrip transmission line has been successfully developed for the mode selection in a millimeter-wave optoelectronic oscillator. The achieved 3-dB bandwidth of this filter is 10.5 MHz (loaded quality factor, Q, is about 3,000) or 0.03 percent at 31.5 GHz with a 3-dB i...

We demonstrate the quality factor Q - (0.8 +/- 0.1) x 10(10) of whispering-gallery modes in fused-silica microspheres at 633 nm, close to the ultimate level determined by fundamental material attenuation as measured in optical fibers. The lifetime of ultimate Q is limited by adsorption of atmospheric water. Monitoring of adsorption kinetics with submonolayer sensitivity by Q factors and frequen...

BACKGROUND Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) vary in volume and quality. We evaluated whether fat volume or attenuation (indirect measure of quality) predicts metabolic risk factor changes. METHODS AND RESULTS Framingham Heart Study Multi-detector Computed Tomography Substudy participants (n=1730, 45% women) were followed up over a mean of 6.2 years. Baseline...