A wave is a disturbance that propagates through space and time, usually with the transference of energy from one point to another without permanent displacement of particles of the medium. The particles under this situation only oscillate about their equilibrium positions. If the particles oscillate in the direction of wave propagation, then the wave is called longitudinal wave. However, if the...

AIM Arterial wall elasticity including the circumferential and longitudinal modulus is a measure of sub-clinical cardiovascular disease; the circumferential modulus is increased in acute ischemic stroke (AIS). There are still no reports of non-invasive measurement of longitudinal elastic modulus of arterial wall and its prospect of clinical application. In this study, the longitudinal elastic m...

detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. this distribution could be detected by different geophysical methods, especially gravity method. however, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. performance of the gravity technique co...

the velocity data of seismic waves in a region has an important role in locating occurred events. information such as velocity ratio of vp/vs and velocity curves for pg, pn, sg, and sn phases directly affect the locating results. it is well known that the vp/vs ratio can be used to predict lithology, and that s-waves are sensitive to microcracks aligned by the present day stress field. also, th...

Using ultrasonic spectroscopy, the frequency dispersions of ultrasonic velocity and attenuation were measured for single crystal 0.72 Pb(Mg1/3Nb2/3)20.28 PbTiO3 (PMN228%PT! with engineered domain structures in the frequency range of 50–110 MHz. We found that the velocity dispersion and attenuation are very small for the longitudinal wave propagating along @001# of the pseudotetragonal state. Ou...

A model describing the behaviour of the gravityand shear-driven liquid films on heated microstructured walls is developed. The hydrodynamic stability of the film flow is investigated using the long-wave theory. It is shown that the longitudinal grooves stabilize the film flow both when the wall is completely or only partially covered by the film. The influence of the thermocapillarity on the fi...

This work presents a cell to measure the dynamic viscosity of liquids using a wave mode conversion from longitudinal to shear waves and vice-versa. The method is based on the measurement of the complex reflection coefficient of shear waves at a solid-liquid interface. The reflected waves at the solid-liquid interface are measured in the longitudinal mode by a large aperture PVDF membrane to avo...

Timeand frequency-domain theory of multiwire magnetic transmission lines is presented for the first time. The familiar theory of electric multiconductor transmission lines (MTL) is based on the manipulation of two matrices, the longitudinal impedance and the transverse admittance. However, for magnetic MTLs, the key matrices are the transverse impedance and the longitudinal admittance. It is sh...

A coupled-mode analysis of 2-D generalized transverse Bragg waveguides (GTBW) with tilted distributed Bragg reflectors is presented. As a result of the absence of inversion symmetry about a plane perpendicular to the guiding stripe, the modes supported by these guides are not separable into the familiar form of transverse standing wave and longitudinal traveling-wave components. This fundamenta...