The applicability of this parameter in comparison to the resonant frequency for assessment of fatigue damage accumulation in a wrought aluminum alloy has been demonstrated, without the need for coupling fluids or independent generation of incident ultrasonic waves. Selleckchem DMXAA The ultrasonic nonlinearity increased and the resonant frequency of the system decreased with initiation and propagation of the major crack. The nonlinear ultrasonic parameter shows greater sensitivity to damage accumulation than the resonant

frequency. The number of cycles for crack propagation, estimated based on the changes in the nonlinear ultrasonic parameter, is in very good agreement with calculated crack growth rates based on the fractography studies. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3169520]“
“A new technique is presented for determination of the diffusion behavior of dyes in fibrous materials. Polyamide

6.6 in filament form has been dyed with an acid dye in different temperatures and times. The microscopic images of the cross sections of dyed samples are captured and the RGB color images G418 of the surfaces are converted to gray scale intensity data. Then, the variations of intensities within the fiber diameter, from the surface to the center of fiber, are analyzed. A linear relation is assumed between the concentration and the intensity for each pixel. The concentration-distance curves are plotted and the pseudo-diffusion coefficient of dye is predicted by using the error function relation between the normalized intensity and diffusion coefficient. According to the results, the index is constant for the samples dyed in different times and

changes significantly by temperature. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1030-1036, 2009″
“Background: Revision of an unsuccessful posterior cruciate ligament (PCL) reconstruction is a complicated clinical procedure with an outcome that may be less satisfactory than that after a typical primary PCL reconstruction. The purpose of this study was to evaluate the reasons for failure of primary PCL reconstructions and to determine the clinical outcomes of revision PCL Compound Library cost reconstruction after a minimum of two years of follow-up.

Methods: Twenty-eight revision PCL reconstructions were performed by a single surgeon. Four cases that involved diverse operative procedures and two cases with a duration of follow-up of less than twenty-four months were excluded; the outcomes of the remaining twenty-two reconstructions were analyzed at the time of the latest follow-up (at least twenty-four months postoperatively). A technique involving a double femoral tunnel, a modified tibial inlay, and Achilles tendon allograft was used in all twenty-two of these revision reconstructions. Seventeen patients (77%) underwent concomitant reconstruction of posterolateral corner structures.