We study the time evolution of wave packets of noninteracting electrons in a twodimensional periodic system in the presence of magnetic and electric fields. The model includes consistently the coupling between Landau levels as well as the periodic and external field contributions. It is shown that the electric field produces localization along its longitudinal direction, this effect is a physic...

Steel embedded in cement mortar in the uniaxial compressive stress direction was found to decrease by 80% the compressive longitudinal strain at a given stress and increase by 300% the tensile transverse strain at a given longitudinal strain. The former effect is due to longitudinal confinement of mortar by steel. The latter is due to debonding at the steel-mortar interface. © 1999 Elsevier Sci...

There has been little interest in the longitudinal movement of the arterial wall. It has been assumed that this movement is negligible compared with the diameter change. Using a new high-resolution noninvasive ultrasonic method, we measured longitudinal movements and diameter change of the common carotid artery of 10 healthy humans. During the cardiac cycle, a distinct bidirectional longitudina...

watermelon is handled and stored in bulk package as some other fruits and vegetables are. package height must be so appropriately selected that bottom fruit layers will receive no damage or failure. this research was performed to determine and compare the mechanical properties of two varieties in three sizes of watermelon under static load conditions to obtain parameters used in transportation ...

Folding of the airway mucosal membrane provides a mechanical load that impedes airway smooth muscle contraction. Mechanical testing of rabbit tracheal mucosal membrane showed that the membrane is stiffer in the longitudinal than in the circumferential direction of the airway. To explain this difference in the mechanical properties, we studied the morphological structure of the rabbit tracheal m...

A planar force-constant model is developed for longitudinal phonons of wurtzite GaN and AlN propagating along the [0001] direction. The proposed model is then applied to the study of the phonon modes in hexagonal (0001)GaN/AlN supperlattices in longitudinal polarization. The confinement of the superlattice phonon modes is discussed. PACS numbers: 68.20.Dj, 68.35.Ja Typeset using REVTEX

1 Abstract— Field trials of a 4 meter long, 180 kilogram, unmanned surface vehicle (USV) have been conducted to evaluate the performance of station-keeping heading and position controllers in an outdoor marine environment disturbed by wind and current. The USV has a twin hull configuration and a custom-designed propulsion system, which consists of two azimuthing thrusters, one for each hull. No...

Shear wave measurements for the determination of tissue elastic properties have been used in clinical diagnosis and soft tissue assessment. A shear wave propagates as a transverse wave where vibration is perpendicular to the wave propagation direction. Previous transverse shear wave measurements could detect the shear modulus in the lateral region of the force; however, they could not provide t...

-poly(vinylidene fluoride)— -PVDF—exhibits ferroelectric properties due to the special arrangement of the chain units in the crystalline phase. The ferroelectric phase can be optimised by poling the original stretched film, that tends to align the randomly organised crystallites against the applied field. In this work, polarised and non-polarised -PVDF from the same batch are characterised by m...