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81.
Tsuyoshi Hyakutake Alexander V Navrotskiy Katsuaki Morita Junji Kato Hirotaka Sakaue Ivan A Novakov Hiroyuki Nishide 《Polymer International》2010,59(10):1436-1440
Active control of flow over object surfaces achieved by means of mechanical and/or electrical methods has recently been studied. However, there has been no report on actively switching the surface drag of an object by chemical modification of the object's surface. Poly(N‐isopropylacrylamide) (PNIPA) was grafted onto the surface of an aluminium (Al) substrate via (A) surface‐initiated atom transfer radical polymerization and (B) radical polymerization with an azo‐group surface initiator. The grafting density was 0.19 and 0.15 chains nm?2, respectively. The water contact angle of the PNIPA‐grafted Al surface reversibly changed between 55° and 82° for (A) and between 42° and 65° for (B) at temperatures of 25 and 40 °C, which was ascribed to the temperature‐responsive, hydrophilic–hydrophobic switching of the grafted PNIPA surface. The PNIPA grafting was applied on the surface of an ogive‐shaped Al model. The normalized dropping speed of the model in water increased 1.1 times at 42 °C in comparison to that at 22 °C. Switching of the surface drag of PNIPA‐grafted Al in water was demonstrated on the basis of the hydrophilicity and hydrophobicity of the grafted Al surface, the switching occurring with a change in temperature. Copyright © 2010 Society of Chemical Industry 相似文献
82.
The gelatin fraction adsorbed on silver iodobromide particles was recovered by dissolution of the particles with sodium thiosulphate. The sodium dodecylsulphate, SDS, electrophoretic pattern of the recovered fraction was clearly different from that of the original gelatin. This is a direct indication of selective adsorption. Extraction of the adsorbed gelatin from the particles was examined with several reagents. Among them, the SDS extract gave a similar electrophoretic pattern to that of the fixation-recovered fraction. Electrophoretic patterns of SDS-extracted fractions from AgCl, AgBr and Agl particles indicate that the absorptions by these silver halides are selective and selectivity by each silver halide is different. 相似文献
83.
Predominance of ammonia-oxidizing archaea on granular activated carbon used in a full-scale advanced drinking water treatment plant 总被引:1,自引:0,他引:1
Ozonation followed by granular activated carbon (GAC) is one of the advanced drinking water treatments. During GAC treatment, ammonia can be oxidized by ammonia-oxidizing microorganisms associated with GAC. However, there is little information on the abundance and diversity of ammonia-oxidizing microorganisms on GAC. In this study, the nitrification activity of GAC and the settlement of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in GAC were monitored at a new full-scale advanced drinking water treatment plant in Japan for 1 year after plant start-up. Prechlorination was implemented at the receiving well for the first 10 months of operation to treat ammonia in raw water. During this prechlorination period, levels of both AOA and AOB associated with GAC were below the quantification limit. After prechlorination was stopped, 105 copies g-dry−1 of AOA amoA genes were detected within 3 weeks and the quantities ultimately reached 106-107 copies g-dry−1, while levels of AOB amoA genes still remained below the quantification limit. This observation indicates that AOA can settle in GAC rapidly without prechlorination. The nitrification activity of GAC increased concurrently with the settlement of AOA after prechlorination was stopped. Estimation of in situ cell-specific ammonia-oxidation activity for AOA on the assumption that only AOA and AOB determined can contribute to nitrification suggests that AOA may account for most of the ammonia-oxidation. However, further validation on AOB contribution is required. 相似文献
84.
85.
Yasuhiro Hayashi Junya Matsuki Shinji Ishikawa Hirotaka Takano Eiji Muto Naoki Kobayashi 《Electrical Engineering in Japan》2009,167(1):56-65
In a distribution system, in order to enhance the reliability of power supply, the distribution feeder is divided into several sections by installing sectionalizing switches, and then each of the sectionalized sections is connected to a different feeder. For example, one feeder is divided into three sections by two sectionalizing switches, and then each of the divided sections is connected to the other feeder through sectionalizing switch. Since a distribution system with many feeders has many sectionalizing switches, the system configuration is determined by states (opened or closed) of sectionalizing switches. Usually, a power utility tries to obtain distribution loss‐minimum configuration among large numbers of configuration candidates. However, it is very difficult to determine the loss‐minimum configuration such that the mathematical optimality is guaranteed, because it is well known that determination of a distribution system's configuration is to decide whether each sectionalizing switch is opened or closed by solving a combinatorial optimization problem. In this paper, the authors propose a determination method of loss‐minimum configuration by which the mathematical optimality is guaranteed for a three‐sectionalized three‐connected distribution feeder network. A problem to determine the loss‐minimum configuration is formulated as a combinatorial optimization problems with four operational constraints ( feeder capacity, voltage limit, radial structure, and three‐sectionalization). In the proposed method, after picking up all partial configurations satisfied with radial structure constraint by using enumeration method, optimal combination of partial configurations is determined under the other operational constraints by using conventional optimization method. Numerical simulations are carried out for a distribution network model with 140 sectionalizing switches in order to examine the validity of the proposed algorithm in comparison with one of conventional meta‐heuristics (tabu search). © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 56– 65, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20530 相似文献
86.
This study was conducted to assess the effect of the composition of mixed fuels on the spray inner structure in an evaporating transient spray under various ambient conditions. The spray structure and spatial distribution of the liquid phase of the multi-component fuels (three-component mixed fuels) were investigated using thin laser sheet illumination with a pulsed Nd-YAG laser as the light source. The experiments were conducted in a constant-volume vessel with optical access. Fuel was injected into the vessel with an electronically controlled common rail injector. In low-volatility multi-component fuel, droplet clusters occur at almost regular intervals resulting from fuel properties such as high liquid density and viscosity of a fuel with a high boiling point. 相似文献
87.
It was reported recently by us that the energy conversion efficiency ηATG of thermoelectric (TE) generators working under the alternating temperature gradient (ATG) produced by switching at an optimum period of τ = 120 or 240 s is several times higher than ηSTG of them operating under the steady temperature gradient (STG), where the generators are sandwiched between two Peltier modules. However, the reason for ηATG > ηSTG has not yet been explained explicitly. In order to clarify the relation between the optimum τ and ηATG or ηATG/ηSTG in the wide range of τ, long p- and n-type Cu/Bi–Te/Cu composites with tBi–Te = 4.0 mm and tCu = 5.0 mm were fabricated so that they have an optimum τ longer than the previous periods. The maxima ηATG of the p- and n-type composites were 0.073% at τ = 960 s and 0.057% at τ = 480 s, respectively, and their ηATG/ηSTG were approximately 1.4. Owing to this experimental result, ηATG/ηSTG is related closely to the thermal diffusion time τD of a composite or a generator, so that ηATG and ηATG/ηSTG were found to be in inverse proportion to τD. The reason for this low ηATG results from the high external resistance and the long τ caused by a thick tBi–Te, in addition to too fat Bi–Te sample giving the high thermal conductance. The maximum ηATG was also found to be expressed successfully by a theoretical expression. 相似文献
88.
Hirotaka Fujimori Naoya Sato Koji Ioku Seishi Goto Tetsuo Yamada 《Journal of the American Ceramic Society》2000,83(9):2251-2254
The spin-lattice relaxation times, T 1 , in α-, β-, and amorphous Si3 N4 have been obtained for the first time, using a multiple-pulse saturation recovery method. The saturation recovery of the 29 Si magnetization follows exponential behavior under magic-angle spinning conditions, within the limits of experimental error. A rather wide dispersion of T 1 values is observed for the phases of Si3 N4 : 284 ± 29 min (–46.686 ppm) and 260 ± 23 min (–48.812 ppm) for the α-phase, 36 ± 4 min for the β-phase, and 11 ± 1 min for the amorphous phase, assuming an exponential recovery. The values obtained for the exponent in the power-law fitting are 0.599(9) (–46.686 ppm) and 0.61(1) (–48.812 ppm) for the α-phase, 0.52(2) for the β-phase, and 0.53(3) for the amorphous phase. 相似文献
89.
90.