PC-Crash is the most popular program for traffic accident simulation in the world. Its first version was developed by Professor Hermann Steffan at Graz University of Technology, Austria, in the early 1990s. It is being used by more than 6000 users such as experts on traffic accident reconstruction and researchers of insurance companies. The program enables simulation of occupant motion and calculation of occupant stress in collisions, as well as simulation of vehicles' three-dimensional motion and collisions. Using PC-Crash-Madymo we reconstructed a rollover accident of tall minivan in which a child was killed by skull fracture. We also carried out a crash test using a tall minivan to simulate the real accident. Through this simulation, we could observe that the occupant dummy fell down in the leaning cabin according to the vehicle's rollover, and its head was squeezed between the pillar and the road surface. Computer simulation is a very useful tool to analyze the impact biomechanics in traffic accidents, but it also needs our certain knowledge about dynamics of vehicles and collisions.

　　　In this study, the load on a shoehorn brace-type plastic ankle-foot orthosis during walking was measured in 9 hemiplegic subjects and 6 non-hemiplegic subjects. A 6-axis force sensor was used to measure the load on the orthosis and a flexible goniometer was used to examine its deformation. Then, range and magnitude of moments and forces acting on the orthosis were calculated along each axis. We found a significant difference in the waveform for load in the longitudinal direction, which plays an important role in walking, between the hemiplegic and non-hemiplegic subjects, as well as significant inter-individual variation in the waveforms obtained from the hemiplegic subjects. These findings suggest that the thickness and shape of the brace should be taken into account when designing an orthosis to meet the functional needs of a hemiplegic patient. The waveform associated with deformation of the orthosis was confirmed to be similar to that of the waveform of the longitudinal load. We believe that the results of our study provide the basic data necessary for construction of a semiautomatic design and fabrication system for orthoses suitable for hemiplegic patients.

It is known that many micro-cracks would be introduced by surface grinding in process of machining of ceramics. The initial cracks appear as series of semicircular surface cracks beneath the grinding groove. Under applied loading some of the cracks coalesce and extend stably to an elongated semi-elliptical surface crack configuration at failure. So, it is needed to predict the existence of the elongated crack before failure. Acoustoelasticity is a non-destructive method not only to detect flaw but also to estimate quantitatively the change of microstructure. In this paper, by examining the dependency of the crack length on the third order elastic constants in two kind ceramics of glass ceramics and partially stabilized zirconia the possibility to nondestructive inspection in ceramics was evaluated. As a result, there was a significant correlation between the crack size and the third order elastic constants, and the application of acoustoelasticity to the estimation of crack damage could be quite possible.

Resistance training (RT) machines are very useful devices for muscle hypertrophy and muscle strengthening. However, RT machines have friction resistance. It causes decrease in lowering movement load and increase in lifting load. The present study was performed to examine how to decrease load in lowering movement compared to lifting movement in RT machines. Low rowing and arm curl were performed as representative RT events in heavy (10 repetition maximum [10RM] load), middle (heavy×0.7) and low (heavy×0.7×0.7) load condition and in normal (1s lifting / 1s lowering), moderate slow (2s lifting /2s lowering) and slow (3s lifting / 3s lowering) movement speed. RT events in several conditions were performed with free weight (FW), gymnastic RT machine (GM) and home use RT machine (HM). The rates of lowering movement phase load compared to lifting movement phase load (ECC/CON: eccentric/concentric) were approximately 100% in FW,88-96% in GM and 51-65% in HM. The decreasing rates in lowering movement in GM and HM were affected a little by movement speed or training load. These results suggest that the decreasing rate in lowering movement in GM is not large, but that in HM is considerably large.

　　　In this study, we investigate a crystal structure change in the exothermic reaction process of Al/Ni films and the bilayer thickness effect by using the BL46XU in the SPring-8. Sputtered Al/Ni multilayer films with the bilayer thickness ranging from 8nm to 100nm are subjected to time-resolved X-ray diffraction analysis. All the films are ignited by electrical shock. No bilayer thickness effect on crystal structure after the reaction is shown, whereas crystal structure before the reaction is dependent on bilayer thickness. As the result, it is thought that the mixing layer influences the propagating exothermic reaction properties of the Al/Ni multilayer films.

　　　Mechanical properties of carbon nanotubes (CNTs) attract much attention because CNTs are expected to have a potential as a structural material for space elevator. However, mechanical properties on individual SWNTs with defined chirality have never been determined experimentally yet, mainly owing to the difficulties in non-destructive determination of their chiral structures and delicate handling of individual SWNTs for mechanical testing. In this study, we develop a damage-free nano manipulation technique to directly examine the mechanical tensile properties of CNTs using a microelectromechanical systems (MEMS) tensile testing device.

　　　Chemical mechanical polishing (CMP) is one of the effective surface-finishing methods for machining Si wafers. However, the conventional CMP process using free abrasive slurry has apparent disadvantages, such as low efficiency, high environmental burden and cost. As a promising technology for the machining of large-sized Si wafer, chemo-mechanical grinding (CMG) integrates the advantages of fixed abrasive machining and CMP process, and hence can generate superior surface quality comparable to that by CMP while maintaining the high geometric accuracy. In this laboratory, we proposed the ultrasonic assisted chemo-mechanical grinding (UA-CMG) process using fixed abrasive to enhance the material removal rate, attain the work-surface with little damage or defects. Although UA-CMG is effective for the improvement of surface roughness and surface morphologies, machined surface characteristics need to be further investigated. In this paper, the evaluation of machined surface texture (Particularly, tool mark and machining defects) using material testing technique is reported. Four-point bending tests of the single-crystal Si wafer processed using UA-CMG are conducted and the influence of surface texture on mechanical properties has been evaluated.

Flow structure in human bronchus is experimentally investigated. Resin bronchus model that is made by 3D printer is provided for the experiment. Velocity distributions are measured by PIV. Microbubble is used as tracer particle of the PIV measurement. Refractive index matching technique are applied to measure velocity in the bronchus model. To simulate non-uniform inlet flow from larynx including Dean vortices, a bent pipe is connected upstream of the bronchus model. Dean number was changed by the radius of curvature of the bent pipe. Due to this inlet condition, velocity distribution in the bronchus model shows distorted top-hat profile. In branch region and curved region of the bronchus model, velocity distributions that indicate adverse pressure gradient condition are confirmed. Separated flows are also confirmed in those region. Dean vortices induced from upstream bent pipe uniformize velocity distribution in the bronchus model. Strong Dean vortices may restrict flow separation in the adverse pressure gradient region. This trend is remarkably observed in higher Dean number condition.