In the context of a continuing investigation of factors that affect the sensitivities of energetic materials to detonation initiation, we have carried out a molecular dynamics characterization of void defects in crystalline (1,3,5-trinitro-1,3,5-triazacyclo-hexane). An empirical force field that is capable of handling flexible molecules in a pliable crystal was used. Voids ranging in size from ...

OBJECTIVE With a microcomputed tomography (microCT) imaging device, we aimed to quantitatively evaluate root canal fillings after commonly used endodontic procedures and also tested the suitability of microCT for this purpose. MATERIALS AND METHODS Eighty single roots were instrumented and obturated with gutta-percha and Tubli-Seal. They were divided into 4 groups of 20. The Hand groups were ...

An analysis is given of thermoelastic noise ~thermal noise due to thermoelastic dissipation! in finite sized test masses of laser interferometer gravitational-wave detectors. Finite-size effects increase the thermoelastic noise by a modest amount; for example, for the sapphire test masses tentatively planned for LIGO-II and plausible beam-spot radii, the increase is &10 percent. As a side issue...

The relation between shortening heat and sarcomere length was studied using fiber bundles from frog semitendinosus muscles as well as using whole muscles. The initial sarcomere length was varied between 2.0 and 3.66 micron. Shortening heat was estimated as the excess heat produced after a rapid isovelocity release in a 3 sec tetanus at 0 degrees C. The isometric control heat was measured in the...

The importance of thermoelastic damping as a fundamental dissipation mechanism for small-scale mechanical resonators is evaluated in light of recent efforts to design high-Q micrometerand nanometer-scale electromechanical systems. The equations of linear thermoelasticity are used to give a simple derivation for thermoelastic damping of small flexural vibrations in thin beams. It is shown that Z...

The thermoelastic properties of ferropericlase Mg(1-x)Fe(x)O (x = 0.1875) throughout the iron high-to-low spin cross-over have been investigated by first principles at Earth's lower mantle conditions. This cross-over has important consequences for elasticity such as an anomalous bulk modulus (K(S)) reduction. At room temperature the anomaly is somewhat sharp in pressure but broadens with increa...

Consider a substitutional solution of two metallic elements A and B. When the alloy is exposed to air at an elevated temperature, A oxidizes, but B does not. In the alloy, the two elements diffuse in opposite directions, but usually at different rates; the nonreciprocal diffusion is known as the Kirkendall effect. At the oxide-alloy interface, metallic atoms may either emit from or inject into ...

this paper deals with the determination of displacement function and thermal stresses of a finite length isotropic functionally graded hollow cylinder subjected to uniform temperature field. the solution of the governing thermoelastic equation is obtained, as suggested by spencer et al. for anisotropic laminates.  numerical calculations are also carried out for fgm (functionally graded material...