Traffic accidents caused by drowsiness have become a large social problem. In this study, we aimed to develop a drowsiness detection system by heart rate variability. Eight subjects particiated in this study. Silent experimental room made them drowsy. The electrocardiogram, the electroencephalogram, the electro-oculogram, the respiration and the pulse wave were measured as physiological indices. The sampling frequency was 2,000 Hz. Video pictures of subjects were taken to monitor their body motion and aspect. Simultaneously, Visual Analog Scale (VAS) was used as a subjective assessment. Heart rate fluctuation was detected using the variance of threshold level that was set by the R-R intervals. The detected zone of drowsy state was assessed by the electroencephalogram and the electro-oculogram. It was only six subjects. Tow subjects could not detect the heart rate fluctuation. The variance of threshold level needs to be improved. We proposed drowsiness detection system using the simple threshold level. This system suggested the possibility to detect the drowsy state.
Time resolved spectral reflectivity of the crystalline silicon surface irradiated with femtosecond laser pulses was observed with ultra short super continuum pulses with varying delay. The heated area of the solid silicon shows entirely different reflectivity spectrum from the crystalline, liquid, or amorphous state, suggesting un-identified novel state before reaching the thermal equilibrium.
We established three cell lines from medaka embryos. In the present study, we investigated the optimal conditions for growth of these cells with regard to the basal culture medium and concentration of fetal bovine serum (FBS). The best cell growth for all three cell lines was achieved with a 1:1 mixture of L15 medium and 199 medium with a relatively high concentration (20%) of FBS. The growth curves for the cell lines revealed that their doubling times ranged from 48 to 93 h. We also analyzed the numbers of chromosomes in the cell lines and found that their numbers varied from near-diploid to hyper-tetraploid. The results of the present study should be helpful for research in fish cell culture.
High-temperature oxidation behavior of Ni-20Cr alloys with small amounts of rare earth elements (Y, Lu) was studied in oxygen for 18ks at 1473K, by mass gain measurements, observation of surface appearance, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mass gains of the Ni-20Cr alloys with rare earth elements decreased with increasing Y and Lu up to 0.5%. The outermost continuous scale on Ni-20Cr alloy consists of NiO which is a planar morphology. On the other hand, the scale on Ni-20Cr-0.5Y (Lu) alloys consists of Cr2O3 which is a fine granular morphology.
We measured a ground-state vibrational temperature of hydrogen molecule in the high density hydrogen plasma generated on diverter simulator TPD-Sheet IV. The hydrogen plasma generated by gas puffing of hydrogen gases measured electron temperature and density with the langmuir probe. The ground-state vibrational temperature of hydrogen molecules was deduced by applying the corona equilibrium with VUV emission spectroscopy(Lyman Band and Werner Band) in the range from 80 to 140 nm.
Microbubble was generated using a fine pore system by flowing oxygen and water solution simultaneously. The experimental condition was varied in concentration and kind of solution for finding more effective generation. Solutions of NaCl, cane sugar and ethyl alcohol of 0.1 to 0.9 mol/l were used. In case of higher concentration of ethyl alcohol solution exhibited the most effective microbubble generation. Generation mechanism was discussed based on the physical and chemical characteristics of solution.
Titanium nitride TiN has considerable hydrogen impermeability and is expected as a prevention coating of hydrogen gas parmiation for a cladding tube of metal hydride fission fuel. The TiN coating produced with plasma process is very complicated because the cladding tube is not wide enough to create stable plasma. A simple reactive evaporation process was selected for coationg process of TiN films to inner wall of narrow tube or stainless steal tube. The films were thermally deposited on stainless steel sheets coiled around inner wall of silica glass tubes. Nitrogen as a reactive gas was introduced into the vacuum chamber with pressure range of 5.0×10-2 Pa ∼ 3.0×10-1 Pa. Thin films with gold color were obtained. From XRD measurement of films, distinct diffraction patterns of TiN phase were observed. A reactivity of N2 gas molecules with Ti atoms in Ti-N film formation has measured quantitatively. The reaction probability of N2 molecules rN2 is defined as the ratio of the absorbing rate of N2 on Ti surface AN2 to the rate of N2 impingement ZN2. Reactive evaporation process exhibits the highest N2 reaction probability rN2 ≅ 0.05. It was the similar value of rN2 with Ti film prepared by ARE plasma processes.
Magnetostrictive properties of Sm-Fe-N and Sm-Fe-C giant magnetostrictive material (GMM) thin film have been systematically investigated in this study. Film samples were prepared by d.c. magnetron sputtering process in Ar-N2 or Ar-CH4 gases atmosphere. Saturated magnetostriction of formed thin films was decreased with increasing of N2 and CH4 partial pressure because of formation of non-magnetic SmN or SmC2 phases. Maximum value of magnetostrictive susceptibility is 34 ppm/kAm-1 was observed in Sm-Fe-C thin film sample with 1.0 vol% CH4 gas partial pressure. Compressive stress of thin film samples was increased due to the increasing of N2 and CH4 gases pressure. The increasing of compressive stress with small N2 and CH4 addition amount into thin film samples may influence the increasing of magnetostrictive susceptibility.
Mechanical properties of DNA have long been thought to play an important role in the packaging of genomic DNA in the nucleus. Using two parameter sets for the flexibility of short base-pair steps, the average flexibility profile of 199 yeast nucleosomal DNAs was calculated. Dramatically decreased flexibilities, or rigid peaks, were observed at intervals of about 10 bp in the profile. Furthermore, it was found that the phase of the rigid peaks overlapped with the phase of the high AA/TT occurrence. These results seem to indicate that periodically spaced rigid regions help DNA to contact with histone core with high affinity.