Considered is the interaction of macro-and micro-cracks in an anisotropic piezoelectric solid. The GreenÕs function and principle of superposition are used to formulate a system of singular integral equations for solving the unknown temperature discontinuity and elastic displacement-electric potential. The residual heat ̄ux, stress and electric displacement on the microcrack are evaluated direc...

o bjectives: the objective of this study was to assess the effect of new bonding techniques on enamel surface. materials and methods: sixty upper central incisors were randomly divided into two equal groups. in the first group, metal brackets were bonded using trans- bondxt and, in the second group, the same brackets were bonded with maxcemelite. the shear bond strength (sbs) of both agents to ...

the micro milling operation is one of the manufacturing processes, which can produce 3d parts in the range of less than a millimetre. miniaturization of components results in increasing the ratio of surface area to volume of components, which in turn increases the role of surface on the component performance. therefore, anticipating the relationship between micro milling parameters and surface ...

Scratch-induced cracking is a serious problem for the use of glass products. At the scratch process, both median (vertical to the glass surface) and lateral (horizontal to the glass surface) cracks are formed. In this study, morphology of the scratch-induced cracks in a commercial soda-lime-silica glass was investigated by the scanning electron microscopy for the specimen broken across the scra...

Micro-cracks are known to greatly affect the mechanical properties of granite and subcritical crack growth (SCG) is considered be main mechanism brittle creep in rocks, including granite. Here, we provide new uniaxial compressive strength experiments for Lanhélin granite, a multi-crack numerical model explain experimental observations. We first thermally-stressed our samples create thermal micr...

X-Ray Refraction Topography techniques are based on Ultra Small Angle Scattering by micro structural elements causing phase related effects like refraction and total reflection at a few minutes of arc as the refractive index of X-rays is nearly unity (1 – 10). The extraordinary contrast of inner surfaces is far beyond absorption effects. Scanning of specimens results in 2D-imaging of closed and...

Vibrothermography often employs a high-power actuator to generate heat on a specimen to reveal damage, however, the high-power actuator brings inconvenience to the application and possibly introduces additional damage to the inspected objects. This study uses a low-power piezoceramic transducer as the actuator of vibrothermography and explores its ability to detect multiple surface cracks in a ...

In an increasingly miniaturised technological world, non-destructive testing (NDT) methodologies able to detect defects at the micro scale are necessary to prevent failures. Although several existing methods allow the detection of defects at that scale, their application may be hindered by the small size of the samples to examine. In this study, the application of bacterial cells to help the de...