Observing the azimuthally varying seismic attenuation in data that show azimuthal velocity anisotropy could contribute not only to the interpretation of the subsurface symmetry systems, but also to the characterization of its physical parameters. In this paper, we estimate azimuthal variations of the P-wave effective quality factor (Q) from field surface seismic data. We also provide an interpr...

In this paper, the link quality in SHF and EHF ranges are studied. In order to achieve high data rate higher frequencies must be used – centimeter waves (SHF), millimeter waves (EHF) or optical range. However, there are significant problem when a radio link work in that diapason – rain attenuation and attenuation in earth’s atmosphere. Based on statistical rain rates data for Bulgaria, the link...

Outdoor images Outdoor images that are captured in inclement weather are degraded due to factors like haze and fog. This factor diminishes the visibility of the image. Haze is formed due to two fundamental phenomena namely, attenuation and the air light. Attenuation reduces the scene contrast and air light increases the whiteness in the scene. Images may also contain impulse noises which are pr...

Abstract Previously, hydrogeologists and petroleum engineers use seepage experiments to measure permeability. This paper develops a novel method calculate matrix permeability from velocity attenuation of an ultrasonic S-wave. At first, is derived as function frequency when S-wave scans fluid-saturated rock. Substituting the into previous model gives theoretical attenuation, in which nexus param...

We use seismic attenuation tomography to identify a region at the top of the lower mantle that displays very high attenuation consistent with an elevated water content. Tomography inversions with >80,000 differential travel-time and attenuation measurements yield 3D whole-mantle models of shear velocity (VS) and shear quality factor (Q ). The global attenuation pattern is dominated by the locat...

This paper describes the design, manufacturing and experiments of a lumped element band pass filter in a new topology. The design starts from a second order capacitive coupled resonator topology. An additional series inductor is inserted in the filter classical topology, for shifting two transmission zeros on the real frequency axes in the filter’s band stop, to improve the high frequency respo...

BACKGROUND Effects of high iodine-concentration contrast material on the image quality of coronary CT angiography (CCTA) have not been well evaluated. PURPOSE To compare the image quality and attenuation values of CCTA between patients administered iopromide 370 and iomeprol 400 with the use of 64-slice multidetector CT. MATERIAL AND METHODS Patients were prospectively enrolled and were ran...

The quality factor Q-value is one of the important parameters for calculating microseismic source parameters, and it also an reference reflecting geological information. However, there are few studies on rock engineering at present, its understanding needs to be further improved. For above reasons, we adopted widely used Atkinson method calculate Q in two engineering. results show that monitori...

To solve noises affecting the performance of laser communication system problems, this paper studies mathematical model in atmospheric attenuation condition, sets up atmospheric attenuation coefficient of the primary factor aerosol (haze) according to the absorbing and scattering characteristics of the atmosphere, gives output SNR(Signal to Noise Ratio) models under atmosphere attenuation based...

Automotive exhaust systems give a major contribution to the sound quality of a vehicle and must be properly designed in order to produce acceptable acoustic performances. Obviously, noise attenuation is strictly related to the internal gas-dynamic field that, on the other hand, needs to be optimised also in terms of pressure losses. In this work, the noise attenuation characteristics of a perfo...