A recent paper (Phys. Rev. Lett. 109, 173201, 2012) has introduced the concept of vibrational conical intersections as a potential source of ultrafast vibrational relaxation, using the coupling between high-frequency OH modes and low-frequency intramolecular hydrogen bonding modes of malonaldehyde as an example. Here, the question is addressed whether such conical intersections may also appear ...

The dynamic response characteristics of a coupled, functionally graded porous conical–conical–cylindrical shell (FGP-CCCS) with arbitrary boundary conditions are investigated using semi-analytical method in this research. individual shells firmly connected at the interface. It is assumed that FGP-CCCS made three types FGP materials uniform or non-uniform distribution porosity along thickness di...

The characterization of the presence bubbles in industrial fluid circuits may be extremely important for many safety issuses. It is well known that acoustic properties liquids can drastically modified by a small amount gaz content liquid. At sufficiently low frequencies, speed sound depends primarily on gas volume fraction. variation fraction then induce some variations vibroacoustic behavior p...

OBJECTIVE Long-term success of dental implants depends on healthy peri-implant soft tissues and adequate bone levels. This prospective study aims to assess bone level changes around implants with internal conical connection and platform-switching abutments in the posterior mandible. MATERIAL AND METHODS Adult patients missing at least two teeth in the posterior mandible and with a natural too...

The potential of buckling in compressive members has been considered as a disadvantage when using steel members in the construction industry. In spite of the progress made in this regard, buckling is still considered as a challenge in the analysis and design of compressive steel structural members. Such a challenging phenomenon can be controlled by strengthening of compressive members. Stiffene...

We present a new method of tailoring the density of a sphere for use as a probe in high pressure-temperature physical property experiments on liquids. The method consists of a composite sphere made of an inner, high density, metallic, spherical core and an exterior, low density, refractory, spherical shell or mantle. Micromechanical techniques are used to fabricate the composite sphere. We desc...

This paper shows that the economy of any country can be presented as three different shells such as: economic shell of a big, a medium and a small business. The new concepts were introduced such as: volume of an economic shell, coefficient of shell’s expansion (compression) etc. These shells can expansion or compress under action by internal or external powers and when shell expansions − it mea...