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41.
Kentaro Yanagihara Jumpei Taketsugu Kiyoshi Fukui Shigeru Fukunaga Shinsuke Hara Ken-ichi Kitayama 《Wireless Personal Communications》2007,40(3):401-415
In this paper, we propose a new energy efficient clustering scheme with transmission power control named “EACLE” (Energy-Aware
CLustering scheme with transmission power control for sEnsor networks) for wireless sensor networks, which are composed of
the following three components; “EACLE clustering” is a distributed clustering method by means of transmission power control,
“EACLE routing” builds a tree rooted at a sink node and sets the paths from sensor nodes taking energy saving into consideration,
and “EACLE transmission timing control” changes the transmission timing with different levels of transmission power to avoid
packet collisions and facilitates packet binding.
With an indoor wireless channel model which we obtained from channel measurement campaigns in rooms and corridors and an energy
consumption model which we obtained from a measurement of a chipset, we performed computer simulations to investigate the
performance of EACLE in a realistic environment. Our simulation results indicate that EACLE outperforms a conventional scheme
such as EAD (Energy-Aware Data-centric routing) in terms of communication success rate and energy consumption. Furthermore,
we fully discuss the impact of transmission power and timing control on the performance of EACLE. 相似文献
42.
T Shirakawa M Onda A Tokunaga I Fujita T Teramoto M Takita T Oguri T Okuda T Kiyama T Yoshiyuki S Kato M Miyashita Z Naito N Matsukura K Yamashita G Asano 《Canadian Metallurgical Quarterly》1996,23(11):1472-1475
Examinations of peritoneal lavage smears (LC) and gastric wall brushing smear cytology (BC) appear to be important for determining accurately the stage of gastric cancer. We have been carrying out such examinations during gastric cancer surgery for 7 years. In the present study, we evaluated the results obtained from 287 patients with gastric cancer. Tumor invasion and peritoneal dissemination were correlated with a positive incidence of cancer cells in LC and/or BC. Gastric cancer showing serosal invasion was classified into positive for LC and/or BC and negative for LC and/or BC. Patients positive for LC and/or BC had a poorer prognosis. For future gastric cancer treatment, patients positive for peritoneal cytology are expected to be targeted for intensive treatment during or before surgery. 相似文献
43.
Yuki Nakashima You Zhou Keisuke Tanabe Souhei Arima Kiyoshi Hirao Tatsuki Ohji Norimitsu Murayama Manabu Fukushima 《Journal of the American Ceramic Society》2023,106(2):1139-1148
Silicon nitride (Si3N4) was prepared from silicon by a sintered reaction-bonded silicon nitride method using yttria and magnesia as sintering additives. Post-sintering (PS) of nitrided compacts was carried out at 1850°C under a nitrogen pressure of 1 MPa. Effect of PS time on microstructure and dielectric breakdown strength (DBS) of the prepared Si3N4 ceramics was evaluated. The DBS was measured using specimens with four different thicknesses (0.30, 0.20, 0.10, and 0.05 mm) in order to examine the thickness dependence. The porosity of the sintered Si3N4 decreased by prolonging the PS time, and the full density could be achieved at the PS time of over 6 h. After full densification, rod-like β-Si3N4 grains grew up, and their maximum grain size increased from 45.1 to 154.7 μm by prolonging the PS time from 6 to 48 h. The DBS of the thick Si3N4 substrates (0.30 mm) showed little variation from 35.4 to 47.0 kV/mm, regardless of the PS time. On the other hand, that of the thin ones (0.05 mm) dramatically decreased from 99.5 to 9.8 kV/mm with increased the PS time from 6 to 48 h. Because the DBS sharply decreased at the thin substrate sintered for longer time in which some large-elongated grains might span the substrate thickness-wise throughout, it was inferred that the interface between β-Si3N4 grains and grain boundary phase/intergranular glassy films might be a path of the dielectric breakdown. 相似文献
44.
Kiyoshi Hirao Koji Watari Manuel E. Brito Motohiro Toriyama Shuzo Kanzaki 《Journal of the American Ceramic Society》1996,79(9):2485-2488
Silicon nitride was fabricated by tape casting of α-Si3 N4 powder with 5 wt% Y2 O3 and 5 vol% rodlike β-Si3 N4 seed particles, followed by tape stacking, hot pressing under 40 MPa, and annealing at 1850°C for 2-66 h under a nitrogen pressure of 0.9 MPa. Silicon nitrides fabricated by this procedure exhibited a highly anisotropic microstructure with large elongated grains (developed from seed particles) uniaxially oriented parallel to the casting direction. Thermal conductivities parallel to the grain alignment were much higher than those measured in other directions and exhibited high values of up to 120 W/(m.K). The anisotropic thermal conductivity of the specimen could be explained by the rule of mixture, considering that large elongated grains developed from seeds have higher thermal conductivity than a small-grained matrix. 相似文献
45.
Kiyoshi Hirao Masayoshi Ohashi Manuel E. Brito Shuzo Kanzaki 《Journal of the American Ceramic Society》1995,78(6):1687-1690
Silicon nitride with a preferred orientation of large elongated grains was obtained by tape casting of raw powder slurry seeded with rodlike β-Si3 N4 particles, followed by a gas pressure sintering under 1 MPa nitrogen pressure. The large elongated grains developed from seeds lay in planes parallel to the casting direction in a two-dimensional distribution. Increased fracture toughness (11.1 MPa·m1/2 ) and bending strength (1100 MPa) were achieved in the direction perpendicular to the grains alignment compared to specimens with a random distribution of elongated grains. Morover, the specimens exhibited a high Weibull modulus of 46 due to the uniform distribution of large grains. 相似文献
46.
Masaki Yasuoka Kiyoshi Hirao Manuel E. Brito Shuzo Kanzaki 《Journal of the American Ceramic Society》1995,78(7):1853-1856
Control of microstructure in the Al2 O3 /LaAl11 O18 system was performed. Elongated alumina grains were formed by doping with small addition of silica, and 20 vol% lanthana- luminate was formed in situ by the reaction of LaAlO3 - A12 O3 in an alumina matrix. Strengths of over 600 MPa and a high fracture toughness (6 MPa.m1/2 ) were achieved in the material with both elongated A12 O3 grains and LaAl11 O18 platelets. Generally antagonistic properties such as strength and fracture toughness have been made compatible in the same ceramic system. 相似文献
47.
Akira Minami Yuuki Kurebayashi Tadanobu Takahashi Tadamune Otsubo Kiyoshi Ikeda Takashi Suzuki 《International journal of molecular sciences》2021,22(6)
Sialidase cleaves sialic acid residues from glycans such as glycoproteins and glycolipids. In the brain, desorption of the sialic acid by sialidase is essential for synaptic plasticity, learning and memory and synaptic transmission. BTP3-Neu5Ac has been developed for sensitive imaging of sialidase enzyme activity in mammalian tissues. Sialidase activity in the rat hippocampus detected with BTP3-Neu5Ac increases rapidly by neuronal depolarization. It is presumed that an increased sialidase activity in conjunction with neural excitation is involved in the formation of the neural circuit for memory. Since sialidase inhibits the exocytosis of the excitatory neurotransmitter glutamate, the increased sialidase activity by neural excitation might play a role in the negative feedback mechanism against the glutamate release. Mammalian tissues other than the brain have also been stained with BTP3-Neu5Ac. On the basis of information on the sialidase activity imaging in the pancreas, it was found that sialidase inhibitor can be used as an anti-diabetic drug that can avoid hypoglycemia, a serious side effect of insulin secretagogues. In this review, we discuss the role of sialidase in the brain as well as in the pancreas and skin, as revealed by using a sialidase activity imaging probe. We also present the detection of influenza virus with BTP3-Neu5Ac and modification of BTP3-Neu5Ac. 相似文献
48.
Morino Y Takahashi K Fushimi A Tanabe K Ohara T Hasegawa S Uchida M Takami A Yokouchi Y Kobayashi S 《Environmental science & technology》2010,44(22):8581-8586
Diurnal variations of fossil secondary organic carbon (SOC) and nonfossil SOC were determined for the first time using a combination of several carbonaceous aerosol measurement techniques, including radiocarbon (1?C) determinations by accelerator mass spectrometry, and a receptor model (chemical mass balance, CMB) at a site downwind of Tokyo during the summer of 2007. Fossil SOC showed distinct diurnal variation with a maximum during daytime, whereas diurnal variation of nonfossil SOC was relatively small. This behavior was reproduced by a chemical transport model (CTM). However, the CTM underestimated the concentration of anthropogenic secondary organic aerosol (ASOA) by a factor of 4-7, suggesting that ASOA enhancement during daytime is not explained by production from volatile organic compounds that are traditionally considered major ASOA precursors. This result suggests that unidentified semivolatile organic compounds or multiphase chemistry may contribute largely to ASOA production. As our knowledge of production pathways of secondary organic aerosol (SOA) is still limited, diurnal variations of fossil and nonfossil SOC in our estimate give an important experimental constraint for future development of SOA models. 相似文献
49.
Effects of the type and amount of fatty acid (0-2.0 mmol/g-starch of lauric, myristic, palmitic, stearic, oleic, and linoleic acids) on the complex formation, thermal properties, and in-vitro digestibility of gelatinized potato starch-fatty acid mixtures were investigated. Complex index (CI) evaluated by the reduction in the iodine binding capacity of starch increased with an increase in the amount of fatty acids, and reached a plateau depending on the type of fatty acid. The maximum CI value was higher in the order of lauric (49.9%), linoleic (47.6%), myristic (42.4%), oleic (36.7%), stearic (35.3%), and palmitic acid (30.9%). From the calorimetric study, it was demonstrated that melting temperature of the complexes was higher in the order of stearic (96.7 °C) > lauric, myristic, palmitic, and oleic (89.6-92.1 °C) > linoleic acid (78.3 °C). Melting enthalpy for complexes was roughly related to the CI value (R2 = 0.667). From the in-vitro digestibility measurement, it was found that a certain amount of fatty acid reduced the starch content hydrolyzed at a given condition. Among them, 0.50 mmol/g-starch lauric and oleic acid samples showed the largest reduction in the hydrolyzed starch content. This result was related to the extent of complex formation characterized by CI value and its helical order characterized by melting temperature. In addition, there was a possibility of the complex formation between amylose and unsaturated fatty acid during the hydrolysis of gelatinized starch. 相似文献
50.
Ichiro Yamanaka Toshikazu Hashimoto Ryo Ichihashi Kiyoshi Otsuka 《Electrochimica acta》2008,53(14):4824-4832
Direct synthesis of H2O2 acid solutions was studied using a gas-diffusion cathode prepared from activated carbon (AC), vapor-growing-carbon-fiber (VGCF) and poly-tetra-fluoro-ethylene (PTFE) powders, with a new H2/O2 fuel cell reactor. O2 reduction to H2O2 was remarkably enhanced at the three-phase boundary (O2(g)-electrode(s)-acid(l)) at the [AC + VGCF] cathode. Fast diffusion processes of O2 to the active surface and of H2O2 to the bulk acid solutions were essential for H2O2 accumulation. Synergy of AC and VGCF was observed for the H2O2 formation. RRDE and cyclic voltammetry studies indicated that the surface of AC functioned as the active phase for O2 reduction to HO2, and VGCF functioned as an electron conductor and a promoter to convert HO2 to H2O2. A maximum H2O2 concentration of 353 mM (1.2 wt%) was accomplished under short-circuit conditions (current density 12.7 mA cm−2, current efficiency 40.1%, geometric area of cathode 1.3 cm2, reaction time 6 h). 相似文献