Investigation on effect of transmit condition on ultrasonic measurement of 2D motion velocity

A phase-sensitive 2D motion estimator is useful for measurement of minute tissue motion. However, the effect of conditions for emission of ultrasonic waves on the accuracy of such an estimator has not been investigated thoroughly. In the present study, the accuracy of the phase-sensitive 2D motion estimator was evaluated under a variety of transmission conditions. Although plane wave imaging with a single emission per frame achieved an extremely high temporal resolution of 10417 Hz, the accuracy in estimation of lateral velocities was worse than compound-based method or focused-beam method. By contrast, the accuracy in estimation of axial velocities hardly depended on the transmission conditions. Also, the phase-sensitive 2D motion estimator was combined with the block matching method to estimate displacements larger than the ultrasonic wavelength. Furthermore, the results show that the correlation coefficient in block matching has potential to be used for evaluation of the reliability of the estimated velocity.

Break even analysis & response of longer span frames with or without post-tensioned beams in multipurpose hall

In this paper analyzed the RC a nd PT Beam against variation in the clear span length of the beam. This work includes the design and estimate of Cost/Beam from 5m span up to 15m span length of the beam. Also, The response of the frame following two variation in its modelling. Initially, The primary model consists of a conventional RCC frame with all beams and columns as RCC. The secondarily model considers peripheral beams as RCC and interior beams with PT. Such as ETABS software used to designed RC beam element and ADAPT-PTRC used to designed PT beam element. However it has been note that variation of cost with respect to the span of beam where the break-even point between RCC and PT technique is approx 7m Span. Also the control on deflection of beam by restrict the depth of beam by using unbonded Post-tensioned prestress concrete beam method. There is very good understand all aspects PT beam better than as compared with to RC beam in deflection against longer span length of beams. This paper gives suggestion about to reach a decidedly conclusion regarding which technique is superior over one another.

Split beam method for determining mode shapes of cantilever beams under multiple loading conditions

We have developed a general method, dubbed the split beam method, to solve Euler–Bernoulli equations for cantilever beams under multiple loading conditions. This kind of problem is, in general, a difficult inhomogeneous eigenvalue problem. The new idea is to split the original beam into two (or more) effective beams, each of which corresponds to one specific load and bears its own Young’s modulus. The mode shape of the original beam can be obtained by linearly superposing those of the effective beams. We apply the split beam method to simulating mechanical responses of an atomic force microscope probe in the “dynamical” operation mode, under which there are a stabilizing force at the positioner and a point-contact force at the tip. Compared with traditional analytical or numerical methods, the split beam method uses only a few number of basis functions from each effective beam, so a very fast convergence rate is observed in solving both the resonance frequencies and the mode shapes at the same time. Moreover, by examining the superposition coefficients, the split beam method provides a physical insight into the relative contribution of an individual load on the beam.

Microstructural evolution and mechanical properties of nano-ATZ ceramics by solid solution precipitation

Alumina toughened zirconia (ATZ) nanoceramics with high-strength, high-toughness and high-hardness were prepared by in-situ nanoprecipitation from solid solution micro-powders. The submicron Al2O3 (~ 450 nm) and ZrO2 (~ 350 nm) grains contained low-density precipitated nano-ZrO2 (~ 40 nm) and nano-Y4Al2O9 (YAM, ~ 90 nm) particles, respectively, making high-performance nano-ATZ ceramics with ultrafine intracrystalline nanostructure yet achieved. There was a parallel or eutectic lattice orientation relationship between the submicrocrystals and its internal nanoparticles of their crystal planes, which is very conducive to the improvement of the mechanical properties of nano-ATZ ceramics. The fracture toughness and hardness of 30wt%Al2O3/70wt%ZrO2(3mol%Y2O3) can be as high as 5.68 ± 0.17 MPa·m1/2 (single-edge V-notched beam method, SEVNB) and 16.32 ± 0.45 GPa, respectively, which are improved by ~ 25 % and ~ 20 % compared with those of 3Y-TZP ceramics. Therefore, this method can be used to prepare nano-ATZ ceramics contained ultrafine nanoparticles and uniform distribution of Al2O3 phases.