[en] In order to study the correlation between the highly resistive property against corrosion and the production method of the ancient iron artifacts, it is essentially necessary to determine the accurate ages of them. ¹⁴C dating with accelerator mass spectrometry was applied to the two ancient artifacts, a Japanese sword of wrought iron with a production age ranged from the Kamakura to the Muromachi period, estimation based on the fabrication technique, and a planning adze of cast iron with no definite origin. The former was dated as 880±150 y.B.P., corresponding to the calendar age ranged from AD 1021 to AD 1263, and the latter as 1720±160 y.B.P. with the calendar age ranged from AD 119 to AD 457 and from AD 483 to AD 508. These calibrated ¹⁴C ages for both iron artifacts are consistent with the relevant ages conjectured by historical considerations. (author)

[en] Stresses greater than the yield point of materials of structures and equipments in the inside of a reactor pressure vessel undergoing neutron irradiation are applied to positions near positions to be welded. For example, water stream jetted out of a nozzle at a high speed is collided against the surface of the structures, so that cavitations are formed by water jetting to apply plastic fabrication on the surface of the structures thereby increasing dislocation. Heat treatment of keeping at a temperature range of from 500 to 900degC for 1 to 60min., and then rapidly cooling is applied to gather He present in the inside of the materials onto the dislocation thereby forming bubbles. Subsequently, welding is performed for repair. Since the amount of He moved to a grain boundary by the heat of welding is reduced, formation of bubbles of He at the grain boundary can be suppressed to prevent occurrence of welding cracks due to lowering of strength at the grain boundary. Accordingly, repair of crack-like flaws such as stress corrosion crackings can be repaired by welding. (I.N.)

[en] To investigate the behavior of hydrogen isotopes in a large fusion test device, a new technique using infrared absorption spectroscopy is applied for the monitoring of hydrocarbons in exhaust gas. Fourier transform infrared (FT-IR) spectroscopy combined with a gas cell, which has an optical path length of 16 m, was installed at the plasma exhaust line. In this configuration, the detection limit of CH₄, C₂H₆, C₂H₄, and CO is at the level of sub-ppm. The exhaust gas observations were conducted during hydrogen glow discharge and during the regeneration operation of cryosorption pumps during the hydrogen plasma phase. As a result, hydrocarbons and carbon monoxide were detected in the exhaust gas, and the exhaust behavior and the ratio of gas components were determined. It is also demonstrated that light and the heavy hydrocarbons can be discriminated by the FT-IR system. Our infrared absorption spectroscopy study provides positive prospects for its application to exhaust gas analyses. (author)

[en] We performed Gd-DTPA-enhanced magnetic resonance imaging (MRI) examinations at several stages in 40 patients with peripheral facial nerve palsy (Bell's palsy and Ramsay-Hunt syndrome). In 38 of the 40 patients, one and more enhanced region could be seen in certain portion of the facial nerve in the temporal bone on the affected side, whereas no enhanced regions were seen on the intact side. Correlations between the timing of the MRI examination and the location of the enhanced regions were analysed. In all 6 patients examined by MRI within 5 days after the onset of facial nerve palsy, enhanced regions were present in the meatal portion. In 3 of the 8 patients (38%) examined by MRI 6 to 10 days after the onset of facial palsy, enhanced areas were seen in both the meatal and labyrinthine portions. In 8 of the 9 patients (89%) tested 11 to 20 days after the onset of palsy, the vertical portion was enhanced. In the 12 patients examined by MRI 21 to 40 days after the onset of facial nerve palsy, the meatal portion was not enhanced while the labyrinthine portion, the horizontal portion and the vertical portion were enhanced in 5 (42%), 8 (67%) and 11 (92%), respectively. Enhancement in the vertical portion was observed in all 5 patients examined more than 41 days after the onset of facial palsy. These results suggest that the central portion of the facial nerve in the temporal bone tends to be enhanced in the early stage of facial nerve palsy, while the peripheral portion is enhanced in the late stage. These changes of Gd-DTPA enhanced regions in the facial nerve may suggest dromic degeneration of the facial nerve in peripheral facial nerve palsy. (author)

[en] To detect ammonia and deuterated hydrocarbons in exhaust gas from the Large Helical Device (LHD), infrared absorption spectrometry, FTIR with a long optical path gas cell, was applied. Ammonia (NH₃) and deuterated hydrocarbons (C_xH_yD_z) could be detected during the first operations of wall baking at 368 K and the D₂ glow discharge conducted after vacuum vessel closure. The concentration of ammonia increased with increasing baking temperature, and deuterated ammonia was not detected. Thus, the ammonia, which likely originated from sweat of workers produced during vacuum vessel maintenance activities, was released from the vacuum vessel wall. Hydrocarbons were likely produced by chemical sputtering of carbon tiles and were deuterated by a hydrogen isotope exchange reaction due to D₂ glow discharge, while H₂O was released from the vacuum vessel during wall baking. It was confirmed that ammonia and various types of deuterated hydrocarbons could be measured discriminately by an FTIR spectroscopy system using a long optical path gas cell. (author)

[en] The wavefront distortion of a large aperture (200 mm) laser beam from a high power glass laser system was directly measured using an interferometric method. The measured static and nonlinear wavefront distortions were used to calculate the intensity distributions at the far field and were then compared with the experimental data. The relationship between the wavefront distortion and the far field pattern thus established is very useful for characterizing the performance of the laser system. (author)

[en] We report the case of a 65-year-old woman with a delayed radiation ulcer and bleeding caused by bevacizumab. She has been undergoing chemotherapy for advanced colon cancer for two years. She received a mastectomy and adjuvant chemoradiotherapy for right breast cancer twenty-one years ago, and colon cancer with liver metastasis was detected using positron emission tomography (PET) two years ago. Since last year she has been treated with bevacizumab chemotherapy bevacizumab due to increased liver metastases. As a result, her radiation ulcer worsened and bleeding occurred repeatedly. On suspicion of an adverse event, we stopped the bevacizumab, and that improved the radiation ulcer and the bleeding. In this case, we discussed radiation induced ulcers, wound healing, and adverse events caused by bevacizumab. (author)

[en] Corrosion of ultra-low carbon type 304 stainless steel in boiling nitric acid solution was analyzed by statistical approach. A large scale mock-up of an evaporator was introduced to perform corrosion test of heat exchanger tubes, and change in loss of wall thickness and intergranular penetration depths of the tubes during test duration was measured and analyzed statistically applying normal distribution and Gumbel distribution. As the results, it was considered that tube wall was corroded uniformly and maximum value of loss of thickness was not exceeded by maximum depth of intergranular penetration. This conclusion means that tube wall thickness measurement can be applied to prevention maintenance against corrosion with intergranular penetration of stainless steel in boiling nitric acid solution. (author)

[en] Corrosion of ultra-low carbon type 304 stainless steel in boiling nitric acid solution was analyzed by statistical approach. A large scale mock-up of an evaporator was introduced to perform corrosion test of heat exchanger tubes, and change in loss of wall thickness and intergranular penetration depths of the tubes during test duration was measured and analyzed statistically applying normal distribution and Gumbel distribution. As the results, it was considered that tube wall was corroded uniformly and maximum value of loss of thickness was not exceeded by maximum depth of intergranular penetration. This conclusion means that tube wall thickness measurement can be applied to prevention maintenance against corrosion with intergranular penetration of stainless steel in boiling nitric acid solution. (author)

No abstract available