background: attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. so, its exact measurement or calculation is very important. the aim of this study was to evaluate the μ in different points in the water phantom analytically ...

The measurement of the solar radiation attenuation is one main challenges in concentrating power technologies. This work presents a new strategy for this measurement, based on analysis VIS and IR spectra, its related system. optical design system implementation central receiver plant described, experimental results are detailed. We present, to best our knowledge, first measurements atmospheric ...

Active acoustic techniques are commonly used to measure oceanic bubble size distributions, by inverting the bulk acoustical properties of the water (usually the attenuation) to infer the bubble population. Acoustical resonators have previously been used to determine attenuation over a wide range of frequencies (10-200 kHz) in a single measurement, corresponding to the simultaneous measurement o...

Lakes are important water resources and integral parts of the natural ecosystem, and it is of great significance to study the evolution of lakes. The area of each lake increased and decreased at the same time in natural condition, only but the net change of lakes’ area is the result of the bidirectional evolution of lakes. In this paper, considering the effects of net fragmentation, net attenua...

Thirty-three in-patients attended for non-contrast enhanced computed tomography (CT) of chest and/or abdomen within a six-week period (11 M, 21 F) . All had measurement of their full blood profile within the previous 72 hours. Patients with a blood dyscrasia or known history of active bleeding were excluded. All patients were imaged using a Siemens Somatom Plus S scanner. The scanning parameter...

where E [V/m] is the amplitude of effective value of the electric field, σ [S/m] and ρ [kg/m] are the electric conductivity and the density of human tissue, respectively. In general, an approximation of a plane wave for the electromagnetic field has been applied to E in eq. (1) in order to represent the SAR characteristics in the internal parts of the head [1], [4]. For example, attenuation cha...

In this paper satellite wave propagation at Ku and Ka band is considered. The design and simulation of a typical satellite beacon receiver at Ka band is designed and simulated for the future works. Also rain attenuation prediction at Ku band using satellite signal beacon measurement and simulations for Iran Telecommunication Research Center (ITRC) are presented. The measurement setup consists o...

Ultrasonic shear-wave propagation studies have been carried out for the measurements of velocity and attenuation in some rocks, concrete and synthetic materials at room conditions. It has been found that ‘pulse broadening’, which occurs due to attenuation, can be measured quite accurately while carrying out shearwave velocity measurements in them. The pulse broadening data could be used to dete...