Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hirao, Norie; Shimoyama, Iwao; Baba, Yuji; Izumi, Toshinori; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
Bunseki Kagaku, 65(5), p.259 - 266, 2016/05
Times Cited Count：4 Percentile：14.35(Chemistry, Analytical)After the Fukushima nuclear plant accident, radiocesium was strongly fixed to clay minerals in the soil. Some dry methods with heating are being developed to remove radiocesium from the soil. In this work, we propose a new dry method that combines heat treatment in vacuum and molten salts to reduce the processing temperature in dry methods. Vermiculite saturated with non-radioactive Cs was heated in vacuum, and Cs contents in the vermiculite were compared before and after heating using X-ray photoelectron spectroscopy. Approximately 40% of cesium were removed by heating at 800
C for three minutes when only vermiculite was heated. Approximately 70% of cesium were removed by heating at 450C for three minutes when vermiculite was heated with NaCl/CaCl
mixed salts. Based on these results, this method is expected to reduce temperature and increase efficiency on dry methods for cesium removal from clay minerals.
Sekiguchi, Tetsuhiro; Baba, Yuji; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Molecular Crystals and Liquid Crystals, 622(1), p.44 - 49, 2015/12
Times Cited Count：0 Percentile：0.01(Chemistry, Multidisciplinary)The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscopy (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images (FOV = ca.50 micro m) for poly(3-hexylthiophene), P3HT thin films were observed under the UV irradiation with various polarization angles, including in-plain and out-of-plain polarization. Morphologies at some bright parts are different each other. The resultant observation suggests that it enables us to distinguish oriented micro-domains with specific directions of polymer chain axis from other amorphous parts.
Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Izumi, Toshinori
e-Journal of Surface Science and Nanotechnology (Internet), 13, p.417 - 421, 2015/09
Times Cited Count：1The interaction between alkali metals and oxides has attracted much attention as heterogeneous catalysis, chemical reaction promoters, and high intensity electron emitter. Also the interaction of cesium and oxides has become important subject, because radioactive cesium trapped in minerals such as clay and soil may cause health risks. In the present study, we analyzed chemical states of ultra-trace amount of cesium on oxide surfaces by total reflection X-ray photoelectron spectroscopy (TR-XPS) exited by synchrotron radiation. For the adsorbed cesium thicker than 0.01 layer, cesium is weakly bound with oxide through Van-der-Waals force. On the other hand, for ultra-thin layer about 0.002 layer, the chemical bond changes to covalent bond. It is suggested that this change in the chemical bonding state is one of the reasons why radioactive cesium is hard to be released from minerals.
Shimoyama, Iwao; Hirao, Norie; Baba, Yuji; Izumi, Toshinori; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
Clay Science, 18(3), p.71 - 77, 2014/09
no abstracts in English
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Photon Factory Activity Report 2013, Part B, P. 546, 2014/00
The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscope (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images for poly(3-hexylthiophene), P3HT thin films were observed under synchrotron X-ray irradiation with linearly polarization. In conclusion, it was found that PEEM with polarized synchrotron can be a powerful tool that gives information of molecular orientation in nano-meter scale.
Ishii, Hirotake*; Shimoda, Hiroshi*; Bian, Z.*; Nakai, Toshinori*; Izumi, Masanori; Morishita, Yoshitsugu; Kanehira, Yoshiki*
no journal, ,
A support method of decommissioning work of nuclear power plants using Augmented Reality was proposed and a prototype system was developed. Then, using the prototype system, the proposed method was evaluated. Three workers used the prototype system along with a scenario which dismantles an ion tower, and then questionnaire and interview investigation was conducted. As the results, it was found that the proposed method that records the cutting parts on the CAD data using a stylus pen was easy and effective compared to the legacy recording method using paper documents, but a new tablet PC that has a larger screen with lighter weight is necessary in order to apply the proposed method to the real decommissioning work.
Ishii, Hirotake*; Bian, Z.*; Sekiyama, Tomoki*; Nakai, Toshinori*; Shimoda, Hiroshi*; Izumi, Masanori; Morishita, Yoshitsugu
no journal, ,
Augmented Reality is one of the promising technologies that will be able to improve efficiency and safety of the nuclear power plant maintenance work. In order to apply the Augmented Reality to the maintenance work, various studies must be done, such as improvement of the tracking technology, improvement of the user interface and human centered evaluation of the Augmented Reality system. The authors have conducted several studies of these issues for almost 5 years. In this paper, a part of these studies are reported.
Shimoda, Hiroshi*; Nakai, Toshinori*; Ishii, Hirotake*; Bian, Z.*; Izumi, Masanori; Morishita, Yoshitsugu
no journal, ,
A support method of decommissioning work of nuclear power plants using Augmented Reality was proposed and a prototype system was developed. Then, using the prototype system, the proposed method was evaluated. Three professionals used the prototype system along with a scenario which dismantles an ion tower,and then questionnaire and interview investigation was conducted. As the results, it was found that the proposed method that records the cutting parts on the CAD data using a stylus pen was easy and effective compared with the legacy recording method using paper instruction sheet, however a new tablet PC that has a larger screen with lighter weight is necessary in order to apply the proposed method to the real decommissioning work.
Izumi, Masanori; Morishita, Yoshitsugu; Shimoda, Hiroshi*; Ishii, Hirotake*; Nakai, Toshinori*; Bian, Z.*
no journal, ,
A support method of decommissioning work of nuclear power plants using Augmented Reality was proposed and a prototype system was developed. Then, using the prototype system, the proposed method was evaluated. Three workers used the prototype system along with a scenario which dismantles an ion tower, and then questionnaire and interview investigation was conducted. As the results, it was found that the proposed method that records the cutting parts on the CAD data using a stylus pen was easy and effective compared to the legacy recording method using paper documents, but a new tablet PC that has a larger screen with lighter weight is necessary in order to apply the proposed method to the real decommissioning work.
Shimoyama, Iwao; Hirao, Norie; Baba, Yuji; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi; Izumi, Toshinori
no journal, ,
no abstracts in English
Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Izumi, Toshinori
no journal, ,
no abstracts in English
Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Izumi, Toshinori
no journal, ,
no abstracts in English
Shimoyama, Iwao; Hirao, Norie; Baba, Yuji; Izumi, Toshinori; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
no journal, ,
We propose a low-pressure sublimation method as a new dry method for reduction of radioactive soil pollutant in Fukushima. We applied heat treatment for weathered biotite saturated and sorbed with 
Cs. Thermogravimetric analysis in low-pressure environment showed a mass decrease due to Cs desorption around 750-800 C, which was not observed in air. Thermal desorption spectroscopy (TDS) showed Cs desorption peak at 680 C in high vacuum environment. This peak shifted to low-temperature side by about 200 C by heating with NaCl-CaCl mixed salt. X-ray fluorescence (XRF) analysis clarified that only negligible amount of Cs was retained in the weathered biotite after heating with the mixed salt at 700 C for two hours. On the other hand, about one-third of Cs can be removed without the salt. These results demonstrated that low-pressure sublimation method can decontamination of Cs from clay minerals using lower temperatures than those for conventional dry methods.
Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Izumi, Toshinori
no journal, ,
In order to clarify the chemical states of radioactive cesium in clay minerals, the X-ray photoelectron spectra (XPS) have been measured for cesium and the other alkali metals on oxides and micaceous oxides. Since the number of atoms in radioactive Cs-137 is extremely small, we focused on the adsorption of trace amount of cesium. For this purpose, we applied total reflection XPS (TR-XPS) using synchrotron radiation. For micaceous oxide, the TR-XPS spectra show that the cesium is more positively charged compared with that for thicker layer. It was shown that trace-level cesium in micaceous oxides is ionically bonded at the interlayer due to the negative charge of the micaceous oxide. We consider that the observed unique adsorption-desorption behavior is specific to only trace-level cesium.
