A database of 1700 digital seismograms from 186 earthquakes of magnitude mN 2.5–5.6 that occurred in southeastern Canada and the northeastern United States from 1990 to 2003 was compiled. Maximum-likelihood regression analysis of the database was performed to determine a model for the attenuation of Fourier spectral amplitudes for the shear window, for the vertical and horizontal component of m...

The impact damage is the most destructive effect on FUM during drum screening. To explore of screening, a free-drop test device was built to simulate FUM. Adopting an L16(45) orthogonal experiment scheme, we investigated mass, dropping height, collision material, and number collisions bruise depth specific surface area bruise, peak force, Ratio amplitude attenuation. Then, analyzed influence th...

Nowadays the technological advancement of information transmission is developing very rapidly and it becomes necessary to achieve a high speed in data as well higher rate. Developments optical communication systems address these needs. However, despite all features advantages systems, dispersion still main challenges. In this paper end, fiber Bragg grating (FBG) used order overcome issue wavele...

In this paper, we present a method to recover the complex wavenumber dispersion relations using spatial Laplace transform from experimental spatiotemporal signals measured by laser ultrasonic technique. The proposed was applied on zero-group-velocity Lamb modes in order extract attenuation polycrystalline aluminum plate of about 70 ?m thickness. difference between and theoretical Fourier transf...

The purpose of this study is to systematically evaluate the usefulness of Positron emission tomography/Magnetic resonance imaging (PET/MRI) images in a clinical setting by assessing the image quality of Positron emission tomography (PET) images using a three-segment MR attenuation correction (MRAC) versus the standard CT attenuation correction (CTAC). We prospectively studied 48 patients who ha...

a study was conducted to determine suitable soil properties as soil quality indicators, using factor analysis in order to evaluate the effects of land use change on loessial hillslope soils of the shastkola district in golestan province, northern iran. to this end, forty surface soil (0-30 cm) samples were collected from four adjacent sites with the following land uses systems: (1) natural fore...

In this work, an inverse problem for the time-independent vector transfer equation for polarized radiation in isotropic medium is examined. In the problem, it is required to find the attenuation factor from known solution of the equation at the medium boundary. A formula is derived that relates the Radon transform of the attenuation factor with the radiation-flux density at the boundary. The un...

The Q-based method of ll impedance matching network design is studied systematically. A more practical definition of the loaded quality factor Q than that used hitherto is adopted. Designable conditions and design formulas based on the loaded Q are analytically demonstrated. Accurate explicit expressions of network frequency responses and harmonic rejection in term of the loaded Q are establish...