著者

Shinichiro UESAWA Susumu YAMASHITA Mitsuhiko SHIBATA Hiroyuki YOSHIDA

出版者

The Japan Society of Mechanical Engineers

雑誌

Mechanical Engineering Journal (ISSN:21879745)

巻号頁・発行日

vol.5, no.4, pp.18-00115, 2018 (Released:2018-08-15)

参考文献数

17

被引用文献数

2

---

A dry method is one of fuel debris retrieval methods for decommissioning of TEPCO’s Fukushima Daiichi nuclear power station. However, the cooling of fuel debris must be fully maintained without water. Japan Atomic Energy Agency (JAEA) has evaluated the air-cooling performance of the fuel debris in the dry method by using JUPITER. Because JUPITER can represent the relocation of the corium, the unknown parameters, such as the composition and the position of the fuel debris at the RPV pedestal, can be reduced. By calculating the heat transfer of the fuel debris based on the corium relocation obtained with JUPITER, more accurate analysis of the air-cooling performance of the fuel debris in the dry method is expected. In order to evaluate the air-cooling performance of fuel debris in the dry method by using JUPITER, the validation of the free-convective heat transfer analysis of JUPITER were performed in this paper. In order to qualitatively evaluate results of JUPITER for configurations closer to experimental conditions and to decide physical values and positions to be measured in the validation, JUPITER was compared with OpenFOAM for the simple cuboid configuration which has the heating and cooling surfaces at the floor and the ceiling, respectively. The comparison proved that JUPITER can calculate the vertical temperature distribution as well as OpenFOAM on the condition of the lower heating amount. In the validation, JUPITER was compared with the heat transfer experiments of free convection in air adjacent to an upward-facing horizontal heating surface. The comparison proved that JUPITER was in good agreement with the experiment on the condition of the lower heating-surface temperature. The result indicated that JUPITER is a helpful numerical method to evaluate the free-convective heat transfer of the fuel debris in the dry method.

著者

Kentaro Iwata Wataru Igarashi Midori Honjo Takashi Nishimoto Kyoko Shinya Akiko Makino Kazuo Mitani Yoshiko Tatsumi Hiroyuki Ninomiya Kumi Higasa Seiichiro Usuki Hiroki Kagawa Daisuke Uchida Kohei Takimoto Rei Suganaga Hiroo Matsuo Yuichiro Oba Mami Horigome Hideaki Oka Goh Ohji Yasuhisa Abe Hiroyuki Yoshida Shohiro Kinoshita Midori Hirai

出版者

日本プライマリ・ケア連合学会

雑誌

General Medicine (ISSN:13460072)

巻号頁・発行日

vol.14, no.1, pp.13-22, 2013 (Released:2013-07-05)

参考文献数

34

被引用文献数

3

---

Background: Gingyo-gedoku-san (GGGS) is an herbal medicine approved for upper respiratory infections in Japan. We conducted an open-label, multi-center, prospective trial, comparing GGGS with oseltamivir in patients with influenza and influenza-like illness (ILI) as a pilot study.Methods: Subjects were healthy persons aged between 16 and 40, and were enrolled from January 12, 2010 to March 24, 2011. Fifteen patients were enrolled in this trial (8 and 7 for GGGS and oseltamivir, respectively). RT-PCR was positive for pandemic influenza A (H1N1) in 10 patients. The patients were provided with either GGGS or oseltamivir for 5 days. The primary outcome was mortality and/or hospitalization 7 days after the initial diagnosis. Body temperature and other clinical characteristics were also evaluated.Results: All patients recovered from illness without complication or hospitalization. The mean time to resolve symptoms for the GGGS and oseltamivir groups was 3.9 days and 3.3 days, respectively (p=0.43). The GGGS group appeared to have a smaller symptom score AUC than the oseltamivir group, (p=0.26). Time to recover activity level appeared to be shorter in the GGGS group (p=0.10), with shorter time to recover health status (p=0.02). Sub-group analysis on patients with positive PCR showed similar results between the two groups.Conclusion: GGGS was associated with symptom improvements resembling oseltamivir for both influenza and ILI. Randomized controlled trials involving larger sample sizes are needed to confirm these results.

著者

Yasuhiro Abe Eiichi Yamamoto Hiroyuki Yoshida Akiko Usui Naomi Tomita Hitomi Kanno Sayaka Masada Hidetomo Yokoo Genichiro Tsuji Nahoko Uchiyama Takashi Hakamatsuka Yosuke Demizu Ken-ichi Izutsu Yukihiro Goda Haruhiro Okuda

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

pp.c20-00431, (Released:2020-08-08)

参考文献数

28

被引用文献数

20

---

The purpose of this study was to elucidate the effect of high-temperature storage on the stability of ranitidine, specifically with respect to the potential formation of N-nitrosodimethylamine (NDMA), which is classified as a probable human carcinogen. Commercially available ranitidine reagent powders and formulations were stored under various conditions, and subjected to LC-MS/MS analysis. When ranitidine tablets from two different brands (designated as tablet A and tablet B) were stored under accelerated condition (40°C with 75% relative humidity), following the drug stability guidelines issued by the International Conference on Harmonisation (ICH-Q1A), for up to 8 weeks, the amount of NDMA in them substantially increased from 0.19 to 116 ppm and from 2.89 to 18 ppm, respectively. The formation of NDMA that exceeded the acceptable daily intake limit (0.32 ppm) at the temperature used under accelerated storage conditions clearly highlights the risk of NDMA formation in ranitidine formulations when extrapolated to storage under ambient conditions. A forced-degradation study under the stress condition (60°C for 1 week) strongly suggested that environmental factors such as moisture and oxygen are involved in the formation of NDMA in ranitidine formulations. Storage of ranitidine tablets and reagent powders at the high temperatures also increased the amount of nitrite, which is considered one of the factors influencing NDMA formation. These data indicate the necessity of controlling/monitoring stability-related factors, in addition to controlling impurities during the manufacturing process, in order to mitigate nitrosamine-related health risks of certain pharmaceuticals.

著者

Hiroyuki YOSHIDA Taku NAGATAKE Kazuyuki TAKASE Akiko KANEKO Hideaki MONJI Yutaka ABE

出版者

一般社団法人日本機械学会

雑誌

Mechanical Engineering Journal (ISSN:21879745)

巻号頁・発行日

vol.1, no.4, pp.TEP0025-TEP0025, 2014 (Released:2014-08-15)

参考文献数

10

被引用文献数

1 1

---

In this study, to develop the predictive technology of two-phase flow dynamics under earthquake acceleration, a detailed two-phase flow simulation code with an advanced interface tracking method TPFIT was expanded to perform two-phase flow simulations under seismic conditions. In the expansion of the TPFIT, the oscillating acceleration attributed to the earthquake motion was introduced into the momentum equation of the two-phase flow as body force. Moreover, to simulate fluctuation of the flow rate and a shear force on a pipe wall, time dependent boundary conditions can be added in the numerical simulations. The bubbly flow in a horizontal pipe excited by oscillation acceleration and under the fluctuation of the liquid flow was simulated by using the modified TPFIT. Furthermore, predicted velocity distribution around the bubbles and shapes of bubbles were compared with measured results under flow rate fluctuation and structure vibration. In the results of numerical simulation, periodical change of shapes of bubbles was observed. In addition, velocity distribution around bubbles also changed in accordance with flow rate fluctuation or structure vibration. Predicted results almost agreed with measured results. In the results, it was confirmed that the modified TPFIT can predict time dependent velocity distribution around the bubbles and shapes of bubbles qualitatively. The main cause of bubble deformation observed from the measured and predicted results is large shear stress at the lower part of the bubble, and this large shear stress is induced by the velocity difference between the liquid phase and bubble. Moreover, by using the predicted results, we discussed about the difference between both effects of flow rate fluctuation and structure vibration on two-phase flow. In the results, bubble acceleration of the structure vibration case was larger than that of the flow rate fluctuation case. Finally, it was concluded that unsteady shear stress induced by vibration of the pipe wall was one of the main driving forces of bubble motion in structure vibration case.