based on two-dimensional plane stress and bifurcation functional from hill's general theory in polar coordinate the critical condition for elastic wrinkling of the flange of a circular blank ( the wave number in the flange and wrinkled area) during the deep-drawing process are obtained analyticaly to improve the previous given results. in this analytical study, the elastic limitation of the mat...

A diffraction theory of continuous-wave photothermal deflection (PD) spectroscopy with fundamental and harmonic responses is presented. The displacement of the probe beam centroid is found to be a rigorous measurement of PD effect, which leads to a set of analytical solutions to the fundamental and the second-order harmonics. Harmonics are caused by the diffraction of the probe beam in the mira...

objectives: the aim of this study was to assess and compare the characteristics of commonly used initial archwires by their load deflection graphs. materials and methods : this study tested three wire designs namely copper nickel titanium (cnt), nickel titanium (niti), and multi-strand niti (msnt) archwires engaged in passive self-ligating (psl) brackets, active self-ligating (asl) brackets or ...

The effect of the temperature variation on a unimorph piezoelectric cantilever is studied. Its influences on the thermal expansion, the piezoelectric constant, the transient part and the creep are experimentally analyzed. Afterwards, a H∞ controller is synthesized in order to reject the thermal disturbance and to reach performances required in micromanipulation. Finally, the closed-loop experim...

this article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. the electrostatic actuation was induced by applying ac-dc voltage between the microbeam and electrode plate. in contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. in additio...

The two current criteria for diagnosis of left anterior fascicular block (LAFB) were evaluated; they are marked left axis deviation (LAD) and a delay in the time of inscription of the intrinsicoid deflection (ID) in lead aVL asynchronous to V6. From 400 electrocardiograms with a LAD of --30 degrees or greater, 62 percent showed asynchronous activation of the left ventricle. There was only a gen...

In an effort to reduce the incidence of decubitus ulcers among wheelchair users, current work in cushion design concentrates on minimizing the pressure at the buttock-cushion interface. Finite element analysis can show the stress levels throughout the soft tissue between the cushion and the ischial tuberosity and give designers a better indication of the effects of a particular cushion. Finite ...

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statement of problem: t-loop is one of the most popular closing loops in orthodontic profession. however its activation is in the contrary to bouschinger effect theory, since the formed bends would be opened during activation. the purpose of this study was to add a helix in a way to be more respondent to the bouschinger effect theory. objectives: to compare the load deflection, maximal elastic ...