The study of water absorption soft rock is great significance to the prevention engineering disasters. However, research on prediction method considering influence composition, porosity, and solute insufficient. Aiming solve above problem, tests are carried out by synthesizing rocks solutions. Then, model established through quantitative analysis data compared with characteristics natural verif...

We show that the recovery after each power drop on the chaotic Low Frequency Fluctuations in a semiconductor laser with optical feedback follows an exponential envelope. The time constant for such exponential behavior was experimentally measured. This recovery time constant and the average time interval between consecutive drops are shown to have different dependences when measured as function ...

An exact solution is obtained for an axisymmetric steady-state‎ ‎thermo-mechanical stresses in a thick functionally graded‎ ‎cylinder‎. ‎The material properties are graded along the radial‎ ‎direction according to an exponential function of radial‎ ‎direction with three constants‎. ‎The advantage of the proposed‎ ‎model‎, ‎compared to the models with two constants such as the‎ ‎linear‎, ‎power ...

Large bandwidths are needed to meet the high-throughput requirements of future wireless communication systems. These larger available at mmWave and sub-THz frequencies, such as V-band ranging from 50 75 GHz D-band 110 170 GHz. In this paper, we present channel measurements in an office environment, covering full D-band. Line-of-Sight (LOS) path loss (PL) is modeled a function frequency distance...

This paper mainly studies the order statistics of geometric distribution. The deduces joint frequency function and conditional statistics, and, obtain prove some important propositions Certain are different from also similar to corresponding exponential distribution.

Rain attenuation is a major shortcoming of microwave transmission. J.S Ojo1, 2, M.O Ajewole1, S.K Sarkar2. An improved approach of predicting rain attenuation cumulative. rain attenuation formula Approach for determining the values of rain attenuation at different.Attenuation due to rain is an important constraint in the designing of the microwave. The paper presents a new prediction model of r...

Previously we described a video signal analysis (VSA) method for measuring backscatter and attenuation from B-Mode image data. VSA computes depth-dependent ratios of the mean echo intensity from a sample to the mean echo intensity from a reference phantom imaged using identical scanner settings. The slope of a line-fit of this ratio (expressed in dB) versus depth is related to the attenuation o...

One of the significant engineering applications of the elastic metamaterial (EMM) is for low-frequency vibration attenuation because of its unusual low-frequency bandgap behavior. However, the forbidden gap from many existing EMMs is usually of narrow bandwidth which limits their practical engineering applications. In this paper, a chirallattice-based EMM beamwith multiple embedded local resona...

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...

We report picosecond ultrasonic measurements of phonon attenuation in a 56 μm thick Si wafer coated with a 25 nm Al film. The measurements are of interest for picosecond ultrasonic imaging schemes, and for investigations of nanoscale heat transport. An ultrafast laser was used to perform the pump-probe experiment. A probe delay stage with a range of several nanoseconds allowed detection of cohe...