327 research outputs found
Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies
We theoretically and experimentally demonstrate energy transfer mediated by
optical near-field interactions in a multi-layer InAs quantum dot (QD)
structure composed of a single layer of larger dots and N layers of smaller
ones. We construct a stochastic model in which optical near-field interactions
that follow a Yukawa potential, QD size fluctuations, and temperature-dependent
energy level broadening are unified, enabling us to examine
device-architecture-dependent energy transfer efficiencies. The model results
are consistent with the experiments. This study provides an insight into
optical energy transfer involving inherent disorders in materials and paves the
way to systematic design principles of nanophotonic devices that will allow
optimized performance and the realization of designated functions
Estimated pretreatment hemodynamic prognostic factors of aneurysm recurrence after endovascular embolization.
BACKGROUND:Hemodynamic factors play important roles in aneurysm recurrence after endovascular treatment. OBJECTIVE:Predicting the risk of recurrence by hemodynamic analysis using an untreated aneurysm model is important because such prediction is required before treatment. METHODS:We retrospectively analyzed hemodynamic factors associated with aneurysm recurrence from pretreatment models of five recurrent and five stable posterior communicating artery (Pcom) aneurysms with no significant differences in aneurysm volume, coil packing density, or sizes of the dome, neck, or Pcom. Hemodynamic factors of velocity ratio, flow rate, pressure ratio, and wall shear stress were investigated. RESULTS:Among the hemodynamic factors investigated, velocity ratio and flow rate of the Pcom showed significant differences between the recurrence group and stable group (0.630 ± 0.062 and 0.926 ± 0.051, P= 0.016; 56.4 ± 8.9 and 121.6 ± 6.7, P= 0.008, respectively). CONCLUSIONS:Our results suggest that hemodynamic factors may be associated with aneurysm recurrence among Pcom aneurysms. Velocity and flow rate in the Pcom may be a pretreatment prognostic factor for aneurysm recurrence after endovascular treatment
ミニープレートの破折
Mini-plate fracture was found in a case of the bone grafting after the segmental mandibular excision, and a case of osteomyelitis in the radiographic follow-up examinations. It was emphasized that usefulness of mini-plate would be evaluated by modification in shape and number of mini-plate used for fixation or reconstruction
High-temperature creep strength and room-temperature fracture toughness of MoSiBTiC alloy
Quite recently, the author and his coworkers have developed a new high-temperature material based on Mo-Si-B alloys with TiC addition for ultrahigh temperature applications. The alloys are produced not by powder sintering but by casting, and the constituent phases are of Mo solid solution, Mo5SiB2 (T2), (Ti, Mo)C and (Mo, Ti)2C. The density is reduced to less than 9.0 g/cm3, which is comparable to that of Ni-base superalloys. The high-temperature compressive strength is much stronger than that of commercial heat-resistant molybdenum alloys such as TZM and MHC in a wide high-temperature range. In this paper, the recent progress of our research and development of the MoSiBTiC alloys is reviewed focusing on high-temperature creep strength and room temperature fracture toughness.
The alloy having a primary phase during solidification of (Ti, Mo)C and thus a higher (Ti, Mo)C volume fraction was examined for tensile creep properties, and it was found that the alloy showed typical tensile creep curves accompanying transient, steady-state and acceleration creep stages in all the test conditions. The creep strength was relatively good, for example, the rupture time at 1350 °C under 170 MPa was about 750 h. The stress exponents, n, in the temperature range of 1400 – 1600 °C and the stress range of 100 – 300 MPa were ≈ 3 while it was 5 – 6 at 1350 °C, suggesting that the rate-controlling process of creep deformation is different between at and below 1350 °C and at and above 1400 °C in the stress range.
Room-temperature fracture toughness of the MoSiBTiC alloys was measured by three-point or four-point bending tests using Chevron-notched specimens. The alloy having the primary phase of (Ti, Mo)C showed the fracture toughness value of better than 15 MPa(m)1/2 at room temperature. The value was better than that of the alloy having a primary phase of Moss and thus a higher Moss volume fraction. The obtained results indicated that (Ti, Mo)C phase works for improving not only high-temperature strength but also room-temperature fracture toughness
Note Taking Activity and its assessment in a Blended Learning Environment
"Note-taking" is a popular skill for all types of learning activities. In recent years, the online educational environment has began spreading rapidly at institutes of higher educational, obviating the need for printed materials or written notes. This means that students’ ability to take notes may decline and this may influence the success of their learning. In order to examine this phenomenon, students' notes were surveyed during a blended learning course in a bachelor level program at a Japanese university. The course consisted of an online test system and face-to-face lectures using ICT equipment. Participant's learning performance was measured using online tests, written essays and a final exam, in addition to the assessment of their notes. The contributions of note-taking activities were measured using statistical tests. As individual note-taking performance may be based on student's characteristics, these contributions were also examined. In the analysis, metrics of participant's characteristics such as personality, information literacy and learning experience were surveyed. Additionally, lexical features of notes taken were extracted using a text analysis technique, and these features were compared with the grades given. Conceptual mapping of the contents of notes was conducted, and the behaviour of good note-takers is discussed using the extracted results.  
Effect of Neutron Irradiation on Strength of Electron Beam Welded Joint of JFMS Steel for Fusion Reactor(Materials, Metallurgy & Weldability)
Impact Property at Cryogenic Temperature of Candidate Materials for Fusion Reactor and Their Electron Beam Welded Joints(Materials, Metallurgy & Weldability)
Strength of Candidate Materials for Nuclear Fusion Reactor and Their Electron Beam Welded Joint at Cryogenic Temperature(Mechanics, Strength & Structural Design)
Silenced Expression of NFKBIA in Lung Adenocarcinoma Patients with a Never-smoking History
Nuclear factor of κ-light polypeptide gene enhancer in B cells inhibitor α (NFKBIA), which is a tumor suppressor gene, was found to be silenced in lung adenocarcinomas. We examined NFKBIA expression, mutations in the EGFR and K-ras genes, and EML4-ALK fusion in 101 resected lung adenocarcinoma samples from never-smokers. NFKBIA expression was evaluated using immunohistochemistry. NFKBIA expression was negative in 16 of the 101 samples (15.8%). EGFR and K-ras mutations and EML4-ALK fusion were detected in 61 (60.5%), 1 (1.0%), and 2 (2.0%) of the 101 samples, respectively, in a completely mutually exclusive manner. Negative NFKBIA expression was observed significantly more frequently among the tumors with none of the three genetic alterations compared to those with such alterations (p=0.009). In addition, negative NFKBIA expression was significantly more frequent among the EGFR-wild type samples compared to the EGFR-mutant samples (p=0.013). In conclusion, NFKBIA expression was silenced in adenocarcinomas without EGFR/K-ras mutations or EML4-ALK fusion, suggesting that the silencing of NFKBIA may play an important role in the carcinogenesis of adenocarcinomas independent of EGFR/K-ras mutations or EML4-ALK fusion
Effect of Neutron Irradiation on Cryogenic Temperature Strength of Aluminum Alloys and Their Electron Beam Welded Joints(Mechanics, Strength & Structural Design)
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