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Ōsaka, Japan

Nakashima Y.,University of Tsukuba | Takeda H.,University of Tsukuba | Ichimura K.,University of Tsukuba | Hosoi K.,University of Tsukuba | And 32 more authors.
Journal of Nuclear Materials | Year: 2015

Abstract This paper describes the results of the experiments performed on Tandem Mirror device GAMMA 10/PDX mainly using a new "divertor simulation experimental module (D-module)" installed on one of the end mirror exits which is specially designed to investigate the physics of plasma detachment. The additional ICRF heating in the anchor-cells, connected to both ends of the central-cell, significantly increases the density in the both cells, which attained the generation of the highest particle flux up to 1023 particles/s m2 at the end-mirror exit. H2 and noble gas injection to enhance the radiation cooling in D-module was performed and a remarkable reduction of the electron temperature (from few tens eV to <3 eV) on the target plate were successfully achieved associated with the strong reduction of particle and heat flux. A significant effect of simultaneous injection with hydrogen and noble gases for detached plasma formation was recognized for the first time. © 2014 Elsevier B.V.

Assadi M.H.N.,Osaka UniversityOsaka | Hanaor D.A.H.,University of Sydney
Applied Surface Science | Year: 2016

Copper dopants are varyingly reported to enhance photocatalytic activity at titanium dioxide surfaces through uncertain mechanisms. In order to interpret how copper doping might alter the performance of titanium dioxide photocatalysts in aqueous media we applied density functional theory methods to simulate surface units of doped anatase (101) planes. By including van der Waals interactions, we consider the energetics of adsorbed water at anatase surfaces in pristine and copper doped systems. Simulation results indicate that copper dopant at anatase (101) surfaces is most stable in a 2+ oxidation state and a disperse configuration, suggesting the formation of secondary CuO phases is energetically unfavourable. In agreement with previous reports, water at the studied surface is predicted to exhibit molecular adsorption with this tendency slightly enhanced by copper. Results imply that the enhancement of photoactivity at anatase surfaces through Cu doping is more likely to arise from electronic interactions mediated by charge transfer and inter-bandgap states increasing photoexcitation and extending surface-hole lifetimes rather than through the increased density of adsorbed hydroxyl groups. © 2016 Elsevier B.V.

Sumiya E.,University of Tokyo | Sumiya E.,Tokyo Medical and Dental University | Sumiya E.,Japan Science and Technology Agency | Negishi-Koga T.,University of Tokyo | And 18 more authors.
Biochemical and Biophysical Research Communications | Year: 2015

TAK1 (encoded by Map3k7) is a mitogen-activated protein kinase kinase kinase (MAP3K), which activates the transcription factors AP-1 and NF-κB in response to receptor activator of NF-κB ligand (RANKL) stimulation, thus constituting a key regulator of osteoclast differentiation. Here we report the functional relevance of the kinase activity of TAK1 in the late stage of osteoclast differentiation in vivo using Ctsk-Cre mice and TAK1 mutant mice in which the TAK1 kinase domain was flanked by loxP. The Map3k7flox/kdCtskCre/+ mice displayed a severe osteopetrotic phenotype due to a marked decrease in osteoclast number. RANKL-induced activation of MAPK and NF-κB was impaired in the late stage of osteoclast differentiation. The absence of suppressive effect of an administered NF-κB inhibitor on the late stage of osteoclastogenesis led us to investigate unknown TAK1 targets in osteoclast differentiation. We performed a phosphoproteomic analysis of RANKL-stimulated osteoclast precursor cells from Map3k7flox/kdCtskCre/+ mice, revealing multiple targets regulated by TAK1 during osteoclastogenesis. Thus, TAK1 functions as a critical regulator of the phosophorylation status of various cellular proteins that govern osteoclastogenesis. © 2015 Elsevier Inc. All rights reserved.

Chen J.,Japan Advanced Institute of Science and Technology | Mazumder R.,Japan Advanced Institute of Science and Technology | Miyaji A.,Japan Advanced Institute of Science and Technology | Miyaji A.,Japan Science and Technology Agency | Miyaji A.,Osaka UniversityOsaka
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

A cryptographic hash is defined as a transformation of variable length-message into a fixed length value. The application of cryptographic hash is increasing day by day. In modern cryptography, it is now defined as “Swiss Army Knife of Cryptography” because of usage in the verify process of integrity for files or messages, verification of the password, file/data identifier, pseudo-random generation and key derivation. The cryptographic hash consists of a compression function, where compression function can be built by scratch or blockcipher. The blockcipher based hash is suitable for constrained device (WSN device) encryption because of direct hardware implementation of the blockcipher. The blockcipher hash can be categorized into (n, n) and (n, 2n) [(block-length, key-length)]. A class of (n, n) is more suitable than the (n, 2n) because of less power and memory utilization. There are some familiar schemes of (n, n) blockcipher hash such as MDC-2, MDC-4, MJH, Bart-12, MSR, where some schemes provide higher security bound and some are good for efficiency. The schemes of MDC-2, MDC-4, Bart, MSR need multiple key scheduling but the MJH needs single key scheduling. The proof technique of early mentioned schemes are based on the ideal cipher model (ICM), except the Bart and MJH. These two follows a model of the finite field multiplicative operation. In this paper, we proposed a scheme of (n, n) blockcipher hash that satisfies a single key scheduling (KS = 1). The collision and preimage resistance of our scheme is bounded by O (2n) and O (22n). Our scheme follows three calls of blockcipher under the Davies Meyer (DM) mode. At first, we use the ICM proof technique. Later, we provide the weak cipher model (WCM) proof technique, which is more rigorous than the ICM. © Springer International Publishing Switzerland 2016.

Koizumi K.,Osaka UniversityOsaka | Tanimoto C.,The International Institute for Advanced StudiesKyoto | Iwasaki Y.,Cyber UniversityFukuoka | Li L.H.,CAS Institute of Geology and Geophysics | And 2 more authors.
Ancient Underground Opening and Preservation - Proceedings of the International Symposium on Scientific Problems and Long-Term Preservation of Large-Scale Ancient Underground Engineering, 2015 | Year: 2016

Fundamental environmental information is necessary to preserve stone caves. An advanced environmental monitoring system, wireless sensor network, was installed in the Longyou Grottoes, China, in August 2010. This study develops a system by which a filed manager and his/her cooperating researchers are able to continuously monitor environmental conditions in and around caves. It confirms that wireless monitoring is effective, even if observed objects, such as Cave 2 and Cave 3, are far from the base station. The outside air did not affect Cave 2 and affected only the upper part of Cave 3 during the surveillance period. These findings are based on the date of first 50 days of monitoring. The next step is to observe the seasonal variations and differences of the caves. © 2016 Taylor & Francis Group, London.

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