نتایج جستجو برای: velocity of longitudinal wave

تعداد نتایج: 21216035  

Journal: :civil engineering infrastructures journal 0
mehdi raoofian naeeni k. n. toosi university of technology, faculty of geodesy and geomatics. morteza eskandari-ghadi university of tehran, faculty of civil engineering.

the problem of propagation of plane wave including body and surface waves propagating in a transversely isotropic half-space with a depth-wise axis of material symmetry is investigated in details. using the advantage of representation of displacement fields in terms of two complete scalar potential functions, the coupled equations of motion are uncoupled and reduced to two independent equations...

2011
K. Sauer

A new type of oscilliton (soliton with superimposed spatial oscillations) is described which arises in plasmas if the electron cyclotron frequency e is larger than the electron plasma frequency ωe, which is a typical situation for auroral regions in planetary magnetospheres. Both highfrequency modes of concern, the Langmuir and the whistler wave, are completely decoupled if they propagate para...

1999
Haifeng Wang Wenhua Jiang Wenwu Cao

Doped piezoceramic lead zircanate titanate has been characterized in the frequency range of 20–60 MHz using ultrasonic spectroscopy. Theoretical analyses were performed for the reflection and refraction of acoustic waves at the interface of water-piezoelectric ceramic. The incident directions of the wave were chosen to be appropriate for ultrasonic spectroscopy measurements. Shear wave spectrum...

2016
Jabid Quiroga John Quiroga Luis Mujica Rodolfo Villamizar Magda Ruiz

In this paper, a guided wave temperature robust PCA-based stress monitoring methodology is proposed. It is based on the analysis of the longitudinal guided wave propagating along the path under stress. Slight changes in the wave are detected by means of PCA via statistical T 2 and Q indices. Experimental and numerical simulations of the guided wave propagating in material under different temper...

2012
Chia-Ying Liu Doris Chen Gisela Teixido-Tura Atul R Chugh Alban Redheuil Antoinette S Gomes Martin R Prince William Hundley David A Bluemke Joao A Lima

Arterial stiffening is related to an intricate interplay between aging and other cardiovascular risk factors. The aortic arch accounts for most of the vascular buffering function and is primarily involved in arterial stiffening. MRI has been used to noninvasively measure strain, distensibility, and pulse wave velocity of the ascending aorta. We report aortic size and stiffness changes over mid ...

2011
Valentina O Puntmann Alun D Hughes Rolf Gebker Cosima Jahnke Jesus G Mirelis Bernhard Schnackenburg Eckart Fleck Frank Rademakers Ingo Paetsch

Objective To investigate the phenotypic relationships between aortic stiffness and left ventricular (LV) stroke volume (SV) and modes of deformation (longitudinal LD and radial -RD) at rest and stress, with preserved and compromised contractile capacity. Background Increased aortic stiffness, measured by pulse wave velocity (PWV), is linked to a range of cardiovascular (CV) risk factors and act...

2012
Marietta Charakida Naveed Sattar Aroon Hingorani Debbie A. Lawlor John E. Deanfield

Methods A total of 6,576 children age 10 to 11 years from the ALSPAC (Avon Longitudinal Study of Parents and Children) were studied. Childhood overweight and obesity were based on body mass index contemporary to vascular measures and supported by other adiposity measures, including fat mass and waist circumference on dual-energy x-ray absorptiometry. Heart rate, blood pressure, flow-mediated di...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1388

abstract sensitive and precise voltammetric methods for the determination of trace amounts of furaldehydes, mainly as furfural (f) and 5-hydroxymethyl-2-furaldehyde (hmf), in waste waters and other matrices is described. determination of total furaldehyde at < ?g g-1 levels in alkaline buffered aqueous media was individually investigated. by the use of ordinary swv and adsorptive square wave ...

2017
J. Hunter Gordon S. Kino D. Barnett G. Herrmann

The theory of acoustoelasticity predicts that a plane longitudinal acoustic wave passing through a solid which is already in a deformed state will propagate with a velocity (v) which is different from the (v0) of the same wave propagating through the undeformed medium. It may be shown that b.v/vo = (v-vo)/vo = B(o1+o2l where o1 and o2 are the principal stress in the plane normal to the wave pro...

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