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71.
Yoshiaki Kikuchi Takeshi Nagatome Taka-aki Mizutani Hiroyuki Yoshino 《Soils and Foundations》2011,51(1):151-165
Cement-treated clay with air foam, which is called Super Geo-Material (SGM), was developed to utilize dredged clay in an effective way. As SGM is mainly used at levels below the ground water table, water permeability and absorption properties of SGM will affect the durability of the material. In this research, the changes in SGM permeability and absorption as functions of the air foam fraction were investigated. First, permeability tests with triaxial apparatus and constant rate of consolidation tests were conducted on samples containing less than 10% of air foam by volume. From the results, air foam was found to be an impermeable medium in SGM. Secondly, a series of permeability tests and absorption tests were conducted for the SGM with different fractions of air foam while observing the specimen with a micro focus X-ray Computed Tomography (CT) scanner. The results showed that the permeability of SGM increased dramatically due to the appearance of interior water channels when the air foam fraction exceeded 30% by volume. The density distribution change and water absorbed zones of the specimens during absorption tests were estimated using the X-ray CT data. From these results, the air in the SGM was found to be progressively substituted with water from the surface to the inside of the specimen and the substituted zone expanded as it made its way to the specimen interior. The expansion velocity of the substituted zone was not affected by the coefficient of permeability but by the fraction of the air in the specimen. 相似文献
72.
Masayuki Ohta Keitaro Kondo Masayuki Matsunaka Hiroyuki Miyamaru Isao Murata Toshiyuki Iida Kentaro Ochiai Chikara Konno 《Fusion Engineering and Design》2009,84(7-11):1446-1449
Integral benchmark experiments with DT neutrons are not always sufficient for nuclear data benchmarking in the MeV region, below 10 MeV. A neutron spectrum shifter, which will be placed between a sample and a DT neutron source, is effective to moderate DT neutrons incident to the sample. In order to estimate effects of the spectrum shifter, the ratio of the contribution of 14 MeV neutrons in the leakage neutron and gamma-ray spectra was calculated with MCNP-4C for an experimental configuration at FNS of JAEA, Japan. The calculations were carried out for a Li2TiO3 sample with a Be, D2O, or 7LiD spectrum shifter. It was found out that the Be shifter was superior to others and the Be shifter was effective to decrease the contribution of 14 MeV neutrons especially for secondary gamma-ray spectrum measurements. 相似文献
73.
Matsui T Matsumura K Hagisawa K Ishihara M Ishizuka T Suzuki M Kurita A Kikuchi M 《IEEE transactions on bio-medical engineering》2002,49(6):621-623
The purpose of this study is to investigate the vascular wall with a thermally self-regulating, cylindrical stent made of a low Curie temperature ferromagnetic alloy. Physiologic saline was circulated in the silicone model vessel implanted with the stent. The stent-temperature remained nearly constant for variable saline flows, saline temperatures, and magnetic flux densities. Stent implants of this type in human blood vessels could potentially enable thermotherapy and temperature determination without catheterization. 相似文献
74.
Steroid cyclophanes, each having a macrocyclic ring attached to four bile acid moieties via chiral lysine connectors, were synthesized, and the binding of the 2-naphthylphenylketone (guest) to the steroid cyclophanes in water was investigated. The circular dichroism spectra of the steroid cyclophane with cholic acid and L-lysine were significantly affected by the binding of the guest, and the induced circular dichroism based on the absorption of the achiral guest was also observed. The binding of the guest to the steroid cyclophane with cholic acids and D-lysines induced changes in the circular dichroism spectra with the opposite sign of the molecular ellipticities. An induced circular dichroism spectral change was not observed upon binding of the guest to the analogous host without OH sites. These results strongly suggest that the guest is conformationally fixed through hydrogen bonding between the carbonyl group of the guest and the steroidal hydroxyl group of the host. The assembly of only four steroid residues on the macrocyclic ring probably provided a hydrophobic nanocavity for hydrogen bonding. 相似文献
75.
The effect of the dispersing procedure on the aggregate size, membrane fluidity and the pharmacokinetics were evaluated for the lipid A analog E5531. The size of the aggregates prepared by the pH-jump method (pH 11.0 → 7.3) was decreased, reaching 20 nm with increasing dispersing time in 0.003 N NaOH (pH 11.0). The membrane fluidity of the aggregates increased with increasing dispersing time. When prepared by the normal dilution method (pH 7.3 → 7.3), the size of the aggregates remained constant at 150 nm and the membrane fluidity was smaller compared to samples prepared by the pH-jump method. Using samples with different degrees of hydration and different membrane fluidities prepared by the pH-jump method, the pharmacokinetics after intravenous administration into rats were evaluated, and the data obtained confirmed that the membrane fluidity was correlated with the pharmacokinetics in rat. In addition, E5531 vials were stable for 24 months at room temperature when used within 24 hr after reconstitution. 相似文献
76.
To investigate the relationship between serum Se contents and the risk of cancer, 4857 serum samples were obtained from cancerous (2730) and non-cancerous patients (2127). In this cohort, the incidence of cancer in the non-cancerous patients was followed for the subsequent 3 years. The serum Se level of non-cancerous patients who later developed cancer during the 3 years was determined and compared with that of the non-cancerous patients. A high incidence of cancer was observed in the lower serum Se patients of the non-cancerous group. The serum Se levels of cancerous patients were significantly lower than in non-cancerous patients. These results suggest that the low serum Se level in cancerous patients may not be induced by the tumor but it was more likely already present before the tumor. To calculate the odds ratio, cancerous and non-cancerous patients were divided into group of less than 110 ppb and more than 111 ppb group in serum Se. The odds ratio was estimated to be 1.95, suggesting the high risk of cancer in the low serum Se group. 相似文献
77.
Okada M. Kikuchi H. Takizawa K. Fujikake H. 《Quantum Electronics, IEEE Journal of》1993,29(1):109-120
The effects of an external optical input on a bistable laser diode (BLD) with inhomogeneous current injection are discussed. The bistable behavior of optical output versus injection current is shown to be variously modified, depending on the wavelength and power of the optical input. Optical set and reset operations and optical logic achieved by optical input pulses can be explained by these characteristics of a BLD modified by an external optical signal. Analysis using rate equations is also offered to help interpretation of experimental results, as well as the optical output and the bias current injected into the BLD 相似文献
78.
79.
Takeshi Naito Hideo Ueda Masao Kikuchi 《Metallurgical and Materials Transactions A》1984,15(7):1431-1436
The characteristic fatigue behavior of carburized and quenched steel with internal oxides and non-martensitic microstructure near the surface was presented through rotating bending fatigue test. The S-N diagram revealed two knees and the specimens continued to fail over 107 stress cycles. The fatigue limit could not be obtained even at 108 stress cycles. The test results were compared to those for the specimens without surface structure anomalies to show the effect of structure anomalies on the fatigue behavior of carburized steel. 相似文献
80.
Satoshi Hayakawa Chikara Ohtsuki Syuji Matsumoto Akiyoshi Osaka Yoshinari Miura 《Computational Materials Science》1998,9(3-4):337-342
Chemical states of fluorine in fluorosilicate glasses in the system MF2-MO-SiO2 (M = Ca, Sr and Ba; SiO2 content < 60 mol%) have been investigated by molecular dynamic (MD) simulations with a perfect ionic two-body potential. Comparison of the results with those derived by X-ray photoelectron spectra of the actual glasses demonstrates that MD simulations reproduce well the bonding states of fluorine in the systems as well as the formation of M-F clusters. The MD generated structure of imaginary glasses, or glasses not obtained by the conventional melt-quench technique, with 70 mol% SiO2 indicates that an acidic environment induces a greater amount of F---Si bonds. Their M-F pair correlation functions plotted against normalized M-F distances suggest that relative ion positions in the clusters are very similar. 相似文献