105 research outputs found
Spectroscopic Properties of Polycyclic Aromatic Compounds. Examination of Nitromethane as a Selective Fluorescence Quenching Agent for Alternant Polycyclic Aromatic Nitrogen Hetero-Atom Derivatives
Article on the spectroscopic properties of polycyclic aromatic compounds and an examination of nitromethane as a selective fluorescence quenching agent for alternant polycyclic aromatic nitrogen hetero-atom derivatives
Tribological properties of cemented carbide rolls in cold sheet rolling
When high elastic modulus rolls are applied to cold rolling, roll flattening becomes smaller than withconventional steel rolls. This factor reduces the rolling load by decreasing the contact length between the rolland the sheet being rolled. Conversely, the smaller roll flattening radius increases the contact angle betweenthe roll and the sheet, which reduces the thickness of the lubricating oil film carried into the roll bite. Thisfactor increases the rolling load by increasing the friction coefficient in the contact area. The influence of theroll material on rolling load appears as the sum of these two factors. However, few studies have attemptedto separate and evaluate their effects. To clarify the effect of the roll material on rolling load, a series ofexperimental cold sheet rolling tests was conducted with cemented carbide rolls and conventional steelrolls. The experimental results showed that the difference of the rolling load between cemented carbide rollsand conventional steel rolls varied with rolling conditions. To investigate the lubricant behavior in rolling,a numerical analysis of the oil film thickness was carried out. Based on the experimental results and thecalculated oil film thickness, the effect of the roll material on rolling load was discussed
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Analysis of an Earthquake-Initiated-Transient in a PBR
One of the Design Basis Accidents (DBA) for a Pebble Bed Reactor has been identified as the âSafe shutdown earthquake with core conduction cooling to passive mode of Reactor Cavity Cooling System.â A new methodology to analyze this particular DBA has been developed at the Idaho National Laboratory (INL). During the seismic event the reactor core experiences the densification of the pebbles, which produce small reactivity insertions due to the effective fuel densification. In addition, a decrease in the active core height results in the relative withdrawal of the control rods, which are assumed to remain stationary during the transient. The methodology relies on the dynamic re-meshing of the core during the transient to capture the local packing fraction changes and their corresponding effects on temperature and reactivity. The core re-meshing methodology is based on the velocity profiles of the pebbles in the core, which were obtained with the INLâs pebble mechanics code PEBBLES. The methodology has been added to the coupled code system CYNOD-THERMIX-KONVEK. The reactor power calculation is further improved with the use of the new advanced TRISO fuel model to better approximate the temperatures in the fuel kernels. During the transient the core is brought back to a safe condition by the strong Doppler feedback from local temperature increases
Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --
Twelve high schools in Japan (of which six are in Fukushima Prefecture), four
in France, eight in Poland and two in Belarus cooperated in the measurement and
comparison of individual external doses in 2014. In total 216 high-school
students and teachers participated in the study. Each participant wore an
electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of
his/her whereabouts and activities. The distributions of annual external doses
estimated for each region overlap with each other, demonstrating that the
personal external individual doses in locations where residence is currently
allowed in Fukushima Prefecture and in Belarus are well within the range of
estimated annual doses due to the background radiation level of other
regions/countries
Literature survey on epidemiology and pathology of gangliocytic paraganglioma
<p>Abstract</p> <p>Background</p> <p>Although gangliocytic paraganglioma (GP) has generally been regarded as a neuroendocrine tumor, its origin remains unclear. We therefore aimed to investigate the details of this disease by carefully analyzing and extracting common features of the disease as presented in selected publications.</p> <p>Methods</p> <p>We searched for English and Japanese cases of GP using the PubMed and IgakuChuoZasshi databases on August 2010. We then extracted and sampled raw data from the selected publications and performed appropriate statistical analyses. Additionally, we evaluated the expression of hormone receptors based on our previously reported case.</p> <p>Results</p> <p>192 patients with GP were retrieved from the databases. Patient ages ranged from 15 y to 84 y (mean: 52.3 y). The gender ratio was 114:76 (male to female, 2 not reported). Maximum diameter of the tumors ranged from 5.5 mm to 100 mm (mean: 25.0 mm). The duodenum (90.1%, 173/192) was found to be the most common site of the disease. In 173 patients with duodenal GP, gastrointestinal bleeding (45.1%, 78/173) was found to be the most common symptom of the disease, followed by abdominal pain (42.8%, 74/173), and anemia (14.5%, 25/173). Rate of lymph node metastasis was 6.9% (12/173). Our statistical analysis indicated that significant differences were found for gender between GP within the submucosal layer and exceeding the submucosal layer. Furthermore, our immunohistochemical evaluation showed that both epithelioid and pancreatic islet cells showed positive reactivity for progesterone receptors.</p> <p>Conclusions</p> <p>Our literature survey revealed that there were many more cases of GP exceeding the submucosal layer than were expected. Meanwhile, our statistical analyses and immunohistochemical evaluation supported the following two hypotheses. First, vertical growth of GP might be affected by progesterone exposure. Second, the origin of GP might be pancreatic islet cells. However, it is strongly suspected that our data have been affected by publication bias and to confirm these hypotheses, further investigation is required.</p
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