Tests of cylindrical specimens of O. 75 in. diameter up to 300.000 psi axial compression stress have been conducted for hardened portland cement paste as well as concrete with !Is in. aggregate. The specimens tightly fit into a cylindrical cavity in a pressure vessel and are loaded axially by a hard piston. The pressure vessel is very stiff, forcing the lateral expansion of specimens to be so s...

The flow induced by a single laser-induced cavitation bubble is used to manipulate individual Co nanowires. The short-lived (<20 μs) bubble with a maximum size of 45 μm is created in an aqueous solution with a laser pulse. Translation, rotation, and radial motion of the nanowire can be selectively achieved by varying the initial distance and orientation of the bubble with respect to the nanowir...

The preliminary phase of any orthodontic treatment with fixed appliances is the alignment and leveling of teeth. Leveling is the process in which the incisal edges of the anterior teeth and the buccal cusps of the posterior teeth are placed on an ideal horizontal level; and alignment is the lining up of teeth of an arch in order to achieve normal contact point relationship. In the alignment pha...

Abstract. We analyze the residuals of GMRES [9], when the method is applied to tridiagonal Toeplitz matrices. We first derive formulas for the residuals as well as their norms when GMRES is applied to scaled Jordan blocks. This problem has been studied previously by Ipsen [5], Eiermann and Ernst [2], but we formulate and prove our results in a different way. We then extend the (lower) bidiagona...

Atomistic simulations are performed to study the nonlinear mechanical behavior of graphene nanoribbons under quasistatic uniaxial tension, emphasizing the effects of edge structures (armchair and zigzag, without and with hydrogen passivation) on elastic modulus and fracture strength. The numerical results are analyzed within a theoretical model of thermodynamics, which enables determination of ...

Changes in the plantar soft tissue shear properties may contribute to ulceration in diabetic patients, however, little is known about these shear parameters. This study examines the elastic and viscoelastic shear behavior of both diabetic and non-diabetic plantar tissue. Previously compression tested plantar tissue specimens (n=54) at six relevant plantar locations (hallux, first, third, and fi...

In this paper, effects of critical parameters, namely initial gap, squeezing speed and applied current were statistically investigated on the mechanical behaviour of MR fluid in squeeze mode. A set of 17 experiments was designed using Design Expert 7 software to gather data from response surface methodology (RSM). The responses in terms of compression modulus were then calculated. An MRF132-DG ...

A lignin-epoxy resin composite was prepared by blending lignin/wood flour with an epoxy resin and polyamine. The effects of the wood flour on the mechanical, thermal creep, and creep recovery properties, as well as the microstructure of the composite, were studied. Among the mechanical properties, the initial modulus increased with increasing content of wood flour. The glass transition temperat...

the most important quality indicator of fruits is the flesh firmness which is well correlated to their young’s modulus. in this research variation of vibration characteristics (shape modes, natural frequency) of apple due to change of material characteristics (density, young's models, poisson ratio) and apple volume was investigated using finite element simulation. an image processing technique...

The controllable fabrication of self-scrolling SiGe/Si/Cr helical nanoribbons on Si(111) substrates is investigated. The initial lateral etching profile of the Si(111) substrates shows a 2-fold rotational symmetry using 4% ammonia solution, which provides guidance for initial scrolling of one-end-fixed nanoribbons to form helical structures. The chirality of the SiGe/Si/Cr helices with isotropi...