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71.
Kensuke Konishi Jun-Ichi Toyooka Kenji Kamiyama Ikken Sato Shigenobu Kubo Shoji Kotake Kazuya Koyama Alexander D. Vurim Valery A. Gaidaichuk Alexander V. Pakhnits Yuri S. Vassiliev 《Nuclear Engineering and Design》2007,237(22):2165-2174
The WF (wall failure) test of the EAGLE program, in which 2 kg of uranium dioxide fuel-pins were melted by nuclear heating, was successfully conducted in the IGR (Impulse Graphite Reactor) of NNC/Kazakhstan. In this test, a 3 mm-thick stainless steel (SS) wall structure was placed between fuel pins and a 10 mm-thick sodium-filled channel (sodium gap). During the transient, fuel pins were heated, which led to the formation of a fuel-steel mixture pool. Under the transient nuclear heating condition, the SS wall was strongly heated by the molten pool, leading to wall failure. The time needed for fuel penetration into the sodium-filled gap was very short (less than 1 s after the pool formation). The result suggests that molten core materials formed in hypothetical LMFBR core disruptive accidents have a certain potential to destroy SS-wall boundaries early in the accident phase, thereby providing fuel escape paths from the core region. The early establishment of such fuel escape paths is regarded as a favorable characteristic in eliminating the possibility of severe re-criticality events. A preliminary interpretation on the WF test results is presented in this paper. 相似文献
72.
Xuan Lian Hiroaki Miyoshi Yuki Mitsuya Kenji Shimazoe 《Journal of Nuclear Science and Technology》2018,55(7):805-811
The liquid crystal display (LCD) technology allows several simple circuits to be built using thin film transistors, thus making fabrication of compact, integrated, large-area, and low-cost micro-pattern gaseous detectors possible. In this work, a single-grid-type micro-strip gas chamber (S-MSGC) using transparent electrodes based on the LCD technology was fabricated and successfully operated in several gas mixtures. The detector was coupled with a multi-pixel photon counter to detect an optical signal through the transparent substrate in Ar/CF4 gas. Both electrical and optical signals were measured and the light yield of the detector was acquired. Successful operation of the S-MSGC can be considered the very important first step for development of the next target of integrated devices. 相似文献
73.
Kazuhiro Nagao Akira Koshino Akane Sugimura-Nagata Aya Nagano Masayuki Komura Akane Ueki Masahide Ebi Naotaka Ogasawara Toyonori Tsuzuki Kenji Kasai Satoru Takahashi Kunio Kasugai Shingo Inaguma 《International journal of molecular sciences》2022,23(6)
p53 immunohistochemistry is considered an accurate surrogate marker reflecting the underlying TP53 mutation status and has utility in tumor diagnostics. In the present study, 269 primary CRCs were immunohistochemically evaluated for p53 expression to assess its utility in diagnostic pathology and prognostication. p53 expression was wild-type in 59 cases (23%), overexpressed in 143 cases (55%), completely lost in 50 cases (19%), and cytoplasmic in 10 cases (4%). p53 immunoreactivity was associated with tumor size (p = 0.0056), mucus production (p = 0.0015), and mismatch repair (MMR) system status (p < 0.0001). Furthermore, among CRCs with wild-type p53 expression, a significantly higher number of cases had decreased CDX2 than those with p53 overexpression (p = 0.012) or complete p53 loss (p = 0.043). In contrast, among CRCs with p53 overexpression, there were significantly fewer ALCAM-positive cases than p53 wild-type cases (p = 0.0045). However, no significant association was detected between p53 immunoreactivity and the “stem-like” immunophenotype defined by CDX2 downregulation and ALCAM-positivity. Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio [HR] = 0.17, p < 0.0001), younger age (HR = 0.52, p = 0.021), and female sex (HR = 0.55, p = 0.046) as potential favorable factors. The analysis also revealed complete p53 loss (HR = 2.16, p = 0.0087), incomplete resection (HR = 2.65, p = 0.0068), and peritoneal metastasis (HR = 5.32, p < 0.0001) as potential independent risk factors for patients with CRC. The sub-cohort survival analyses classified according to chemotherapy after surgery revealed that CRC patients with wild-type p53 expression tended to have better survival than those with overexpression or complete loss after chemotherapy. Thus, immunohistochemistry for p53 could be used for the prognostication and chemotherapy target selection of patients with CRC. 相似文献
74.
Junie P. Warrington Qingmei Shao Ahsia M. Clayton Kenji J. Maeda Ashtin G. Beckett Michael R. Garrett Jennifer M. Sasser 《International journal of molecular sciences》2022,23(6)
As the resident immune cells of the central nervous system, microglia have a wide range of functions such as surveillance, phagocytosis, and signaling through production of chemokines and cytokines. Recent studies have identified and characterized macrophages residing at the meninges, a series of layers surrounding the brain and spinal cord. While perivascular microglia within the brain parenchyma increase following chronic hypertension, there are no reports of changes at the meninges, and specifically, associated with the pial vasculature. Thus, we used female Sprague Dawley and Dahl salt-sensitive (SS/Jr) rat brains, stained for ionized calcium-binding adapter molecule (Iba1), and characterized microglia/macrophages associated with pial vessels in the posterior brain. Results indicate that Iba1+ pial vessel-associated microglia (PVAM) completely surrounded the vessels in brains from the Dahl-SS/Jr rats. PVAM density was significantly higher and distance between PVAMs lower in Dahl-SS/Jr compared to the Sprague Dawley rat brains. Pregnancy history did not affect these findings. While the functional role of these cells are not known, we contextualize our novel findings with that of other studies assessing or characterizing myeloid cells at the borders of the CNS (meninges and choroid plexus) and perivascular macrophages and propose their possible origin in the Dahl-SS/Jr model of chronic hypertension. 相似文献
75.
A compact sodium-cooled reactor is an important candidate as a fast breeder reactor (FBR) and has been investigated in the feasibility study of FBR cycle. Due to the compact sizing of the reactor vessel, gas entrainment at the free surface of sodium coolant becomes one of the significant issues for reactor design, and it is required to clarify the criterion of gas entrainment at free surface and the tolerance. In the present study, some visualization experiments were performed in a water-air system focusing on the gas entrainment due to surface vortex and its transient phenomena. Influences of horizontal velocity were clarified by the visualization. The gas entrainment due to the surface vortex occurs intermittently. Time trends of circulation and length of gas core for the intermittent surface vortices were measured by the particle image velocimetry and visualization. It was found that the gas core length extends with time delay to the increase of circulation around the vortex. 相似文献
76.
Takeshi Kobayashi Yuki Imade Daisuke Shishihara Kenji Homma Miki Nagao Ryota Watanabe Toshiyuki Yokoi Atsuo Yamada Ryoji Kanno Takashi Tatsumi 《Journal of power sources》2008
A high-capacity type of all solid-state battery was developed using sulfur electrode and the thio-LISICON electrolyte. New nano-composite of sulfur and acetylene black (AB) with an average particle size of 1–10 nm was fabricated by gas-phase mixing and showed a reversible capacity of 900 mAh g−1 at a current density of 0.013 mA cm−2. 相似文献
77.
Riza Muhida Minwon Park Mohammed Dakkak Kenji Matsuura Akira Tsuyoshi Masakazu Michira 《Solar Energy Materials & Solar Cells》2003,75(3-4):697-706
Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented.Based on the characteristics of voltage–current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC–DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously.This method uses a proportional integrator controller to control the duty factor of DC–DC converter with pulse-width modulator (PWM).The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. 相似文献
78.
As a model-based reinforcement learning technique, linearly solvable Markov decision process (LMDP) gives an efficient way to find an optimal policy by making the Bellman equation linear under some assumptions. Since LMDP is regarded as model-based reinforcement learning, the performance of LMDP is sensitive to the accuracy of the environmental model. To overcome the problem of the sensitivity, linearly solvable Markov game (LMG) has been proposed, which is an extension of LMDP based on the game theory. This paper investigates the robustness of LMDP- and LMG-based controllers against modeling errors in both discrete and continuous state-action problems. When there is a discrepancy between the model used for building the control policy and dynamics of the tested environment, the LMG-based control policy maintained good performance while that of the LMDP-based control policy deteriorated drastically. Experimental results support the usefulness of LMG framework when acquiring an accurate model of the environment is difficult. 相似文献
79.
80.
Pharyngeal bolus flow was simulated numerically using a finite element method. The bolus liquids were X-ray medium, glucose, and thickener solutions. For a low-viscosity bolus, the simulation showed a reasonable agreement of bolus velocity with X-ray measurements. The influence of bolus density on swallowing velocity was investigated numerically. Although a higher density resulted in a higher bolus velocity, the increase in velocity was modest. When the bolus viscosity was high, it was necessary to apply the slip boundary condition to obtain an agreement for bolus velocity between the simulation and X-ray measurements. The simulations also showed that the method of characteristic shear rate proposed by Zhu et al., Journal of Texture Studies, 2014, 45, 430–439 is effective for predicting the bolus velocity for shear-thinning fluids. In order to discuss the effect of saliva lubrication and the physical meaning of the characteristic shear rate, an immiscible two-layer flow of the core and wall layer was analyzed theoretically by analogy with mesopharyngeal bolus flow. The characteristic shear rate enabled us to correlate the macroscopic flow behavior and the viscosity of the core layer fluid. Lubrication due to the wall layer caused the apparent slip and enhanced the transfer of viscous core fluid. For viscous fluid that presented a large apparent slip in the two-layer model, the slip boundary condition was needed in the swallowing simulation. The numerical simulation and model flow analysis revealed the usefulness of characteristic shear rate and the importance of saliva-layer lubrication in swallowing. 相似文献