A comprehensive review on dual approach to the vibration analysis: Some dual techniques and application

This paper reviews key ideas of the researches on the dual approach to the vibration analysis. Three types of dual techniques, namely, forward - return dual technique, global-local dual technique, weighted averaging dual technique for the problem of equivalent replacement are summarized. Different implements and realizations of dual techniques to nonlinear vibration analysis and design of dynamic absorbers are reviewed. Finally, the challenging issues based on the dual techniques are discussed. A number of possibilities for developing analytical techniques related to dual techniques are proposed. The review shows that the dual approach is an appropriate one and the dual techniques are effective tools for studying random and deterministic nonlinear vibrational systems

A model of an optical biosensor detecting environment

Heller et. Al. (Science 311, 508 (2006)) demonstrated the first DNA-CN optical sensor by wrapping a piece of double-stranded DNA around the surface of single-walled carbon nanotubes (CN). This new type of optical device can be placed inside living cells and detect trace amounts of harmful contaminants by means of near infrared light. Using a simple exciton theory in nanostructures and the phenomena of B-Z structural phase transition of DNA, we investigate the working principle of this new class of optical biosensor from DNA by using the nanostructure surface as a sensor to detect the property change of DNA as it responds to the presence of target ions. We also propose some new design models by replacing carbon nanotubes with graphene ribbon semiconductors.Comment: 4 pages, 4 figures, Accepte

Temperature dependent graphene suspension due to thermal Casimir interaction

Thermal effects contributing to the Casimir interaction between objects are usually small at room temperature and they are difficult to separate from quantum mechanical contributions at higher temperatures. We propose that the thermal Casimir force effect can be observed for a graphene flake suspended in a fluid between substrates at the room temperature regime. The properly chosen materials for the substrates and fluid induce a Casimir repulsion. The balance with the other forces, such as gravity and buoyancy, results in a stable temperature dependent equilibrium separation. The suspended graphene is a promising system due to its potential for observing thermal Casimir effects at room temperature.Comment: 5 pages, 4 figures, in APL production 201

Irreducible representations of Upq[gl(2/2)]

The two-parametric quantum superalgebra $U_{pq}[gl(2/2)]$ and its representations are considered. All finite-dimensional irreducible representations of this quantum superalgebra can be constructed and classified into typical and nontypical ones according to a proposition proved in the present paper. This proposition is a nontrivial deformation from the one for the classical superalgebra gl(2/2), unlike the case of one-parametric deformations.Comment: Latex, 8 pages. A reference added in v.

A new type of optical biosensor from DNA wrapped semiconductor graphene ribbons

Based on a model of the optical biosensors (Science 311, 508 (2006)) by wrapping a piece of double-stranded DNA around the surface of single-walled carbon nanotubes (SWCNT), we propose a new design model of this sensor, in which the SWCNT is replaced by a semiconductor graphene ribbon (SGR). Using a simple theory of exciton in SGRs, we investigated transition of DNA secondary structure from the native, right-handed B form to the alternate, left-handed Z form. This structural phase transition of DNA is the working principle of this optical biosensor at the sub cellular level from DNA and semiconductor graphene ribbons.Comment: 5 pages, 4 figures; Published on JAP (2012

Repulsive and attractive Casimir interactions in liquids

The Casimir interactions in the solid-liquid-solid systems as a function of separation distance have been studied by the Lifshitz theory. The dielectric permittivity functions for a wide range of materials are described by Drude, Drude-Lorentz and oscillator models. We find that the Casimir forces between gold and silica or MgO materials are both the repulsive and attractive. We also find the stable forms for the systems. Our studies would provide a good guidance for the future experimental studies on the dispersion interactions.Comment: 6 pages, 5 figures, submitted to Phys. Rev. A (2011). arXiv admin note: minor text overlap with arXiv:1002.260