Statistical discussions on skin frictional drag of turbulence over randomly distributed semi-spheres

application/pdfInternational Journal of Advances in Engineering Sciences and Applied Mathematics. 2018, 10 (4), P.263-272journal articl

Heat transfer enhancement by feedback blowing and suction based on vortical structure in turbulent channel flow at low Reynolds number

Heat transfer enhancement is essential in low Reynolds number flow because recent small heat exchangers require narrow flow passages. In the present study, we conducted direct numerical simulations of the channel flow to investigate the turbulence sustaining effect by feedback blowing and suction from the wall. The initial flow field corresponded to the fully developed turbulent channel flow, and the Reynolds number suddenly decreased at the beginning of the simulation. The results indicated that there are two approaches for the turbulence maintenance. If the amplitude of the blowing and suction is high, then the sensor detects the blowing and suction from the wall, and the velocity fluctuation corresponds to self-maintenance. Then, we obtained large heat transfer. However, the gain was small. If the amplitude is moderate, then the blowing from the wall to the low-speed streaky structures pushes up, and the suction attracts the high-speed streak toward the wall. The effect to increase the Reynolds shear stress and heat transfer results in the promotion of the turbulence and heat transfer with high gain.journal articl

骨伝導音声の品質改善方式

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Search for matter-dependent atmospheric neutrino oscillations in Super-Kamiokande

We consider ν_μ→ν_τ oscillations in the context of the mass varying neutrino (MaVaN) model, where the neutrino mass can vary depending on the electron density along the flight path of the neutrino. Our analysis assumes a mechanism with dependence only upon the electron density, hence ordinary matter density, of the medium through which the neutrino travels. Fully-contained, partially-contained and upward-going muon atmospheric neutrino data from the Super-Kamiokande detector, taken from the entire SK-I period of 1489 live days, are compared to MaVaN model predictions.We find that, for the case of 2-flavor oscillations, and for the specific models tested, oscillation independent of electron density is favored over density dependence. Assuming maximal mixing, the best-fit case and the densityindependent case do not differ significantly.journal articl

Study of Time-Dependent CP Violation in B0→J/ψπ0 Decays

journal articl

人文学部 情報科学基礎 1コマコース (平成18年度)

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Monitoring Incorporation of Strontium Citrate in Human Bone using a Novel Non-Invasive Diagnostic Tool, in vivo XRF: A case study

A previously developed in vivo X-ray fluorescence (IVXRF) I-125 based system was used to measure bone strontium levels non-invasively in an osteoporotic female volunteer. The volunteer was recruited in December 2008, as part of the Ryerson and McMaster University Strontium in Bone Research Study and measured at twice weekly, weekly and monthly intervals. Thirty minute measurements were taken at the finger and ankle bone sites, representing primarily cortical and trabecular bone, respectively and the strontium K-alpha X-ray peak at 14.16 keV was used in the analysis. Since the volunteer had no prior history of strontium based medications or supplementation, baseline natural strontium levels were obtained followed by a 24h measurement of first intake of strontium citrate supplements (680 mg Sr/day). While the baseline levels of 0.38 ± 0.05 and 0.39 ± 0.10 for the finger and ankle, respectively, were on par with those previously reported in Caucasians among twenty-two healthy non-supplementing strontium individuals by our group, an increase began to be seen after 24 hrs of 0.62 ± 0.14 and 0.45 ± 0.12 for the finger and ankle, respectively. By 120 h, the increase was statistically significant at 0.68 ± 0.07 and 0.93 ± 0.05, respectively. Further increases occurred within an interval of 90-180 days, with the most recent, after 800 days, at the finger and ankle being 7 and 15 times higher than the initial baseline reading. The intriguing results show bone strontium incorporation and retention follow a pattern, suggesting strontium levels, at least in the ankle, do not plateau within two to three years and will continue to increase over time, as an individual takes strontium supplements. The ability of this IVXRF system to monitor and measure bone strontium levels over time provides a useful diagnostic tool to help gain insight into strontium bone kinetics.</p

Quantification of bone strontium levels in humans by in vivo X-ray fluorescence

The need for in vivo bone strontium assessment arises because strontium may exert a number of effects on bone, which may be either beneficial or toxic. Measurements discussed here are noninvasive, no sample is taken, nor is there discomfort to patients. The developed source excited x-ray fluorescence system employs a 109Cd source to excite the strontium K x rays, with the source and detector in approximately 90 degree geometry relative to the sample position. The factors affecting the accuracy and minimal detectable limit for bone strontium in vivo measurements are discussed. A system calibration revealed a minimum detectible limit of approximately 0.25 mg Sr/g Ca, which is sufficient for the monitoring of strontium levels in healthy subjects and patients with elevated bone strontium concentrations. Preliminary in vivo measurements in ten healthy subjects at two bone sites (phalanx and tibia) indicated that this system can be applied for cumulative bone strontium estimation while delivering a low effective dose of 80 nSv during the measurement time. Future work will involve attempts to enhance system precision with alternative fluorescing sources and further optimization of the detection system.</p

Temperature Dependence of Magnetically Active Charge Excitations in Magnetite across the Verwey Transition

We study the electronic structure of bulk single crystals and epitaxial films of Fe3O4. Fe 2p core level spectra show clear differences between hard x-ray (HAX) and soft x-ray photoemission spectroscopy (PES). The bulk-sensitive spectra exhibit temperature (T) dependence across the Verwey transition, which is missing in the surface-sensitive spectra. By using an extended impurity Anderson full-multiplet model-and in contrast to an earlier peak assignment-we show that the two distinct Fe species (A and B site) and the charge modulation at the B site are responsible for the newly found double peaks in the main peak above TV and its T-dependent evolution. The Fe 2p HAXPES spectra show a clear magnetic circular dichroism (MCD) in the metallic phase of magnetized 100-nm-thick films. The model calculations also reproduce the MCD and identify the contributions from magnetically distinct A and B sites. Valence band HAXPES shows a finite density of states at EF for the polaronic half metal with a remnant order above TV and a clear gap formation below TV. The results indicate that the Verwey transition is driven by changes in the strongly correlated and magnetically active B-site electronic states, consistent with resistivity and optical spectra.journal articl

Trattato dell'arte della pittura, scoltura et architettura /

Contiene: Libro primo de la proportione naturale, et artificiale de le cose ... - Libro terzo del colore ... - Libro quarto de i lumi ... - Libro quinto della prospettiva ... - Libro sesto della prattica della pittura ... - Libro settimo dell'historia di pittura ...Edit16,CCBE s. XVI,Mode of access: Internet.Marca tip. en portada (Edit16, U45)Colofón en h. 2X8v.Grabado xilográfico en h. B1r, retrato del autor.Error de paginación, de p. 692 pasa a la 695.Sign.: 8, 212, A-Z8, 2A-2X8