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101.
Sung‐Jin Kim David Lai Joong Yull Park Ryuji Yokokawa Shuichi Takayama 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(19):2925-2934
This paper gives an overview of elastomeric valve‐ and droplet‐based microfluidic systems designed to minimize the need of external pressure to control fluid flow. This Concept article introduces the working principle of representative components in these devices along with relevant biochemical applications. This is followed by providing a perspective on the roles of different microfluidic valves and systems through comparison of their similarities and differences with transistors (valves) and systems in microelectronics. Despite some physical limitation of drawing analogies from electronic circuits, automated microfluidic circuit design can gain insights from electronic circuits to minimize external control units, while implementing high‐complexity and high‐throughput analysis. 相似文献
102.
Taigo Onodera Shuichi SuzukiTakaaki Mizukami Hisao Kanzaki 《Journal of power sources》2011,196(19):7994-7999
An improved synthesis scheme of non-precious metal N-doped carbon catalysts for oxygen reduction reaction is reported. The non-precious metal N-doped carbon catalysts were prepared by pyrolysis of the mixture (phenol resin, Ketjen black carbon support and cobalt phenanthroline complex). The drastic improvement of distribution state of Ketjen black supported non-precious metal N-doped carbon catalysts was observed by means of transmission electron microscopy (TEM). In addition, the non-precious metal N-doped carbon catalyst synthesized with Ketjen black carbon support showed much higher oxygen reduction reaction (ORR) activity relative to unsupported non-precious metal N-doped carbon catalyst in O2-saturated 0.5 mol l−1 H2SO4 at 35 °C. Moreover, the highest ORR activity was obtained with addition of optimum amount of Ketjen black carbon support was thirtyfold compared to unsupported non-precious metal N-doped carbon catalyst at 0.7 V. Similarly, the performance of a polymer electrolyte fuel cell (PEFC) using the non-precious metal N-doped carbon catalyst as the cathode electrode catalyst was obviously better than that of the non-precious metal N-doped carbon catalyst before optimization. Microstructure, specific surface area and surface composition of the non-precious metal N-doped carbon catalysts were analyzed by XRD, XPS and BET measurement with nitrogen physisorption, respectively. 相似文献
103.
A field survey on energy consumption by hot water supply and cooking was conducted in two cities in China, Nanjing, and Hefei. In each city, 5 housing complexes were selected, and approximately 100 or 200 residential units were selected from each of them. The following items were surveyed: (1) fundamental information, such as number of family members, data on residents, etc., (2) bathing style, and (3) frequency of cooking and cooking time. Most of the residents take showers seven times a week in the summer, but less frequently in the winter. In contrast, the frequency of taking baths increases to several times a week during the winter, compared with 0 or 1 times a week in the summer. These results differ slightly depending on the heating and cooling systems used in the houses. The frequency with which people cook in their own houses ranges from 4 to 7 times a week, which means that “eating out” is relatively frequent, although the result differs significantly among the housing complexes. Distribution of the cooking time has usually two peaks at 20 to 30 min and 50 to 60 min (or 30 to 40 min and longer than 60 min) for lunch and dinner, respectively. The high energy consumption for cooking might be due to the long cooking time. 相似文献
104.
Shin Kajita Naoaki Yoshida Reiko Yoshihara Noriyasu Ohno Takanori Yokochi Masayuki Tokitani Shuichi Takamura 《Journal of Nuclear Materials》2012,421(1-3):22-27
Helium plasma irradiation and electron heating experiments were conducted using tungsten in the divertor simulator NAGDIS-II. Helium plasma irradiation to tungsten led to the formation of nanostructures on the surface, while the nanostructures were annihilated after the potential of the specimen was changed to positive for several 10 min so that electrons irradiated the sample without ion irradiation. The specimens were analyzed in detail by transmission electron microscope with the help of focused ion beam technique. It is revealed that the helium nano-bubbles still remained even after the nanostructures were disappeared from the surface. Porosity of the nanostructured tungsten was measured from the TEM images. 相似文献
105.
The performance of a conventional parallel application is often degraded by load‐imbalance on heterogeneous clusters. Although it is simple to invoke multiple processes on fast processing elements to alleviate load‐imbalance, the optimal process allocation is not obvious. Kishimoto and Ichikawa presented performance models for high‐performance Linpack (HPL), with which the sub‐optimal configurations of heterogeneous clusters were actually estimated. Their results on HPL are encouraging, whereas their approach is not yet verified with other applications. This study presents some enhancements of Kishimoto's scheme, which are evaluated with four typical scientific applications: computational fluid dynamics (CFD), finite‐element method (FEM), HPL (linear algebraic system), and fast Fourier transform (FFT). According to our experiments, our new models (NP‐T models) are superior to Kishimoto's models, particularly when the non‐negative least squares method is used for parameter extraction. The average errors of the derived models were 0.2% for the CFD benchmark, 2% for the FEM benchmark, 1% for HPL, and 28% for the FFT benchmark. This study also emphasizes the importance of predictability in clusters, listing practical examples derived from our study. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
106.
Abstract A numerical study is performed to investigate heat transfer and fluid flow in the entrance and fully developed regions of an annulus, consisting of a rotating, insulated inner cylinder and a stationary, heated outer cylinder. Several different k-ε turbulence models are employed to determine the turbulent kinetic energy, its dissipation rate, and the heat transfer performance. The governing boundary layer equations are discretized by means of a control volume finite difference technique and numerically solved using the marching procedure. In the entrance region the axial rotation of the inner cylinder induces a thermal development and causes an increase in both the Nusselt number and the turbulent kinetic energy in the inner cylinder wall region. In the fully developed region, an increase in the Taylor number causes an amplification of the turbulent kinetic energy over the whole cross section, resulting in a substantial enhancement in the Nusselt number. These transport phenomena are also affected by the radius ratio and Reynolds number. 相似文献
107.
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109.
Preparation and characterization of Maillard reacted chitosan films with hemicellulose model compounds 总被引:1,自引:0,他引:1
The Maillard reaction between chitosan and hemicellulose model compounds such as mannose, xylose, and glucuronic acid was investigated. Chitosan and the compounds were dissolved in 1% acetic acid and were dried at 50°C. In an analysis of the film obtained, weight increase, color difference, FTIR, relative amount of free amino groups, insolubility to dilute acetic acid, and tensile properties were measured. The film weight increased gradually as the compounds were added, and the color difference changed significantly. In addition, the relative amount of free amino groups decreased rapidly, and the insoluble matter increased markedly. In particular, xylose brought about drastic changes in a small amount addition. According to the results of FTIR spectra, the cleavage of sugar unit of chitosan and the formation of heterocyclic compounds were observed in all compounds. The formation of carbonyl and carboxyl groups was observed with the addition of a large amount of the compounds. The tensile strength was improved in 10–20 wt % additions of the compounds. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献
110.
Shuichi Takamura 《IEEJ Transactions on Electrical and Electronic Engineering》2012,7(Z1):S19-S24
A unique plasma‐generation device called the “Aichi Institute of Technology‐Plasma Irradiation Device” has been developed for plasma–wall interaction (PWI) studies toward realization of a fusion reactor. It has power‐saving characteristics as well as compactness due to the employment of a multicusp magnetic field configuration instead of a strong axial magnetic field. Helium as well as argon plasmas are generated, showing an outstanding property of production of the hot‐electron component which can be controlled by changing the working gas pressure. Utilizing such outstanding properties, some typical studies on PWI are introduced. An azimuthally asymmetric confinement depending on the direction of magnetic field lines, particularly for energetic electrons, has been found. Some discussions on the physical mechanisms are given. IEEJ Trans 2011 DOI: 10.1002/tee.21801 相似文献