THE EFFECT OF TURNING DIRECTION ON LOWER EXTREMITY JOINT MOMENTS DURING FAST CUTTING MOVEMENT

The purpose of this study was to investigate the effect of turning movement on the three-dimensional moments at the ankle, knee, and hip joints. Data were collected using video cameras and force plate. Eight male recreational basketball players were tested during fast running (4.5m/s) and when cutting to the right or left off (+60, +30, 0, -30, and -60). The inverse dynamics approach was used to integrate the body segment parameter, kinetic and force plate data, and to solve the resultant joint moments. Greater abduction moments of the ankle, adduction moments of the knee and external rotation and adduction moments of the hip were found compared to values for straight running. Greater inversion and adduction moments of the ankle, abduction moments of the knee and hip were found compared to values for straight running

Improvement of Wood CT Images by Consideration of the Skewing of Ultrasound Caused by Growth Ring Angle

For the purpose of removing distortions in ultrasonic computerized tomographic (CT) images of wood, this study proposes a technique for taking into account the skewing effect in reconstructing the image. First, it was experimentally confirmed that an ultrasonic wave is refracted because of the anisotropic characteristics of wood. Transmission paths of an ultrasonic wave through a cross-section of wood were predicted by considering the change in wave velocity based on the annual ring angle and the presence of juvenile wood. Then, the methodology of the application of the predicted paths to CT image reconstruction was proposed and verified. The accuracy of defect detection in wood was significantly improved by the proposed technique

Effect of Apneic Oxygenation via Nasal Prong on Gas Exchange and Vital Signs during Fiberoptic Intubation under General Anesthesia

A clinical study for the evaluation of the effect of apneic oxygenation by nasal prong during fiberoptic orotracheal intubation on gas exchange and vital signs has been done on the patients who received tympanomastoidectomy (ASA c1assfication 1 and 2, aged from 20 to 40). Among them, 22 patients were selected whose fiberoptic intubation lasted more than 3 but less than 4 minutes, to observe the changes of Pa02, PaC02, HR, and MAP. 11 patients who underwent fiberoptic orotracheal intubation in apneic state without oxygen administration (Group I) showed similar increases in vital signs to the other 11 patients who received apneic oxygenation (Group II). PaC02 increased more in Group I than in Group II, which was not statistically significant. The differences of Pa02 at 1 and 2 minutes between two groups after removal of oxygen mask and beginning of fiberoptic intubation, were not statistically significant but Group II showed a significantly lesser degree of decrease in Pa02 at 3 minutes. We might say that apneic oxygenation during fiberoptic intubation under general anesthesia is useful because it could delay the onset of hypoxia, thereby provide extra time for intubation. Therefore we could attempt intubation up to 3 minutes on the fully relaxed patient, if we give oxygen via nasal prong

Optimization of Printed Circuit Heat Exchanger Using Exergy Analysis

A printed circuit heat exchanger (PCHE) with zigzag flow channels in a double-faced configuration was optimized to enhance its thermal-hydraulic performance. Using exergy analysis, the objective function was defined as the net exergy gain of the system considering the exergy gain by heat transfer and exergy loss due to friction in the channels. A Reynolds-averaged Navier-Stokes (RANS) analysis and surrogate modeling techniques were used for the optimization. Three geometric variables were selected as the design variables. The objective function was calculated at each design point through RANS analysis in order to construct a response surface surrogate model. Through the optimization, both the thermal and hydraulic performances of the PCHE were improved with respect to the reference geometry by suppressing flow separation in the channels