The property of “return to equilibrium” is established for a class of quantum-mechanical models describing interactions of a (toy) atom with black-body radiation, or of a spin with a heat bath of scalar bosons, under the assumption that the interaction strength is sufficiently weak. For models describing the first class of systems, our upper bound on the interaction strength is independent of t...

experiments were carried out to observe the influence of loading type on concrete beam specimens. beam specimens made of similar concrete mixture with the same geometry were tested under three point static loading and low velocity drop weight impact loading. load – displacement behavior, absorbed energy dissipation capacity, stiffnesses, failure modes of beam specimens were obtained and discuss...

[1] The solar wind is filled with strong current sheets and sudden velocity shears; often the two are co-located. Sudden velocity shears at 1 AU are statistically analyzed using ACE measurements from 1998 to 2008. The occurrence rates of passage and the orientations of the shear planes are examined. For shear layers with vector velocity changes |Dv| > 50 km/s, an average of 12 pass the Earth pe...

abstract stepped spillways are of most important hydraulic constructions to dissipation energy of water flow. these constructions are used in opening channel to transfer water from upper level to lower level. because of considerable effect of steps on flow dissipation energy and also the resulted developments in construction of roller competed concrete rcc, the mentioned constructions have draw...

In this study, we develop a multiscale method to study intrinsic damping in nano-structure. Vibrational frequencies in the range of few GHz are considered. Deformation of the structure, at such high rates of vibration, results in a nonequilibrium phonon distribution. The condition of local equilibrium, as is often used in the existing mutli-scale approaches, no longer remains valid. The nonequi...

Damping characterizes the energy dissipation capacity of materials and structures, and it is affected by several external factors such as vibrating frequency, stress history, temperature, and stress amplitude. This study investigates the relationship between the damping and the stress amplitude of environment-friendly recycled aggregate concrete (RAC). First, a function model of a member's loss...

We study the problem of body-force driven shear flows in a plane channel of width ℓ with free-slip boundaries. A mini-max variational problem for upper bounds on the bulk time averaged energy dissipation rate ǫ is derived from the incompressible Navier-Stokes equations with no secondary assumptions. This produces rigorous limits on the power consumption that are valid for laminar or turbulent s...

Ultrananocrystalline diamond (UNCD) films are promising for radio frequency micro electro mechanical systems (RF-MEMS) resonators due to the extraordinary physical properties of diamond, such as high Young’s modulus, quality factor, and stable surface chemistry. UNCD films used for this study are grown on 150 mm silicon wafers using hot filament chemical vapor deposition (HFCVD) at 680°C. UNCD ...

This work examines the quality factors (Q factors) of resonance associated with the axial and transverse vibrations of single-wall carbon nanotube (SWCNT) resonators through the use of molecular dynamics (MD) simulation. Specifically, the work investigates the effect of device length, diameter, and chirality, as well as temperature, on the resonant frequency and quality factor of these devices,...

BACKGROUND Hyperosmotic stress causes cell death through activation of apoptotic pathways if the protective osmolyte response is impaired. In this study we attempt to elucidate the molecular mechanisms of hypertonicity-induced apoptosis and the effect of major organic osmolytes upon those. METHODS Hypertonicity-induced changes in Bcl2-family protein abundance and the presence of cytochrome c ...