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91.
The rates which particles from JIS Test Powders 1, Class 2 (silica sand), Class 3 (silica sand), Class 16 (calcium carbonate, heavy), and JIS Test Powder 2, Class GBM-20 (barium titanate glass) settled out of homogenous suspensions were determined using the principles of the buoyancy weighing-bar method as well as a sedimentation balance. Samples were standardized by Japanese Industrial Standard, and the dispersing agent was NaPP or NaHMP, while the viscosity improver was a starch syrup solution. Although constructing a handmade sedimentation balance is difficult, developing a handmade weighing tool capable of measuring particle size distribution is easy. Herein three weighing-bars, which were composed of aluminum, stainless steel, and copper, were used to measure the particle size distribution. However, an aluminum slit-cylinder occasionally replaced the weighing-bars. The weighing data obtained via an analytical balance were controlled by connecting the balance to a personal computer with an RS-232C interface, and the determined particle size agreed well with the data obtained by Andreasen analyses and the sedimentation balance. 相似文献
92.
A centrifugal force plays an important role on the control of combustion synthesis. In the present work, the data of reaction propagation rates obtained by changing the direction of reaction propagation and centrifugal force are evaluated in order to make clear the effect of centrifugal force on reaction propagations and product formation. As a result, the reaction propagation rate in the case of the direction of centrifugal force inverse to reaction propagation is larger than that in the case of the same direction, and product grains become smaller in size. It is confirmed that the centrifugal effect is much larger for the present combustion synthesis process in the case that the reaction propagates inversely to the direction of centrifugal force. Since molten titanium near combustion front tends to coalesce into larger drops in that case, reactants of boron and carbon would diffuse more sufficiently into titanium. 相似文献
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96.
Determination of optimal sending voltage profile in distribution systems with distributed generators
Yasuhiro Hayashi Junya Matsuki Ryoji Suzuki Eiji Muto 《Electrical Engineering in Japan》2007,161(2):16-24
Sending voltage profile of distribution feeder is controlled by changing a tap of distribution transformer. In a distribution network with distributed generators, for reasons of effect of reversed flows from them and existence of a great number of sending voltage profile candidates, it is not easy to control sending voltage profile within the acceptable voltage limit. In this paper, in order to determine the optical sending voltage profile of distribution transformer in a distribution network with distributed generators, the authors propose a new method to determine the optimal sending voltage profile so as to minimize the total number of tap position's change per day under constraints of acceptable voltage limit. In the proposed method, after calculating acceptable range of three‐phase voltage of distribution feeder, the optimal profile of tap position within the calculated acceptable voltage range is determined among these candidates by using reduced ordered binary decision diagram (ROBDD) which is an efficient enumeration algorithm. In order to check the validity of the proposed method, numerical simulations are carried out for a distribution network model with a distributed generator. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(2): 16–24, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20393 相似文献
97.
The spatial distribution of Zn2+ during galvanic corrosion of a model Zn/steel couple in 0.01 M NaCl was investigated using a scanning zinc disk electrode. The couple had a coplanar arrangement of a steel substrate with an electroplated zinc layer at the center. During galvanic corrosion, the marked changes in the Zn2+ concentration were confined to a thin solution layer ca. 1.0 mm thick above the couple surface. In this thin solution layer above the zinc layer, a higher concentration region of Zn2+ in the range of 5-18 mM extended around the zinc layer in the solution during galvanic corrosion. Conversely, above the steel surface distant from the zinc layer, the surface concentration of Zn2+ was almost zero during galvanic corrosion. On this surface, the precipitation of zinc corrosion products due to the hydrolysis reaction of Zn2+ was observed. The distribution of the Zn2+ concentration supported that Zn2+ acted as a buffer that suppressed the increased pH due to the cathodic reaction on the steel surface near the zinc layer and almost no corrosion products formed there. The spatial distribution of Zn2+ is discussed in relation to the distributions of potential and pH and the surface morphology of the galvanic couple. 相似文献
98.
Samia Tabassum Eiji Yamasue Hideyuki Okumura Keiichi N. Ishihara 《Journal of Materials Science: Materials in Electronics》2014,25(11):4883-4888
Al-doped ZnO (AZO) thin film, which possess the advantages of low cost, low sheet resistance and high transmittance, are one of the most promising candidates to replace indium tin oxide films as the transparent electrode. However, oxidation causes a substantial increase in the sheet resistance of AZO film after exposing in ambient and especially, damp heat environment. In this work, we compare structural, optical, electrical properties and environmental stability between films prepared by two different methods: sol–gel and rf sputtering. Experimental results indicate that the properties of film can be affected by different deposition method. From the X-ray diffraction analysis, all films have hexagonal wurtzite crystal structure with different preferable orientation in two different methods. Optical transmittance spectra of the AZO films exhibited transparency higher than about 80 % within the visible wavelength region and the optical band gap (Eg) of these films was increased in sputtered film, probably due to the increase of carrier concentration. The better environmental stability was found in AZO film prepared by sputtering method. Improved surface morphology and enhancement of crystal orientation (110) was considered for this improvement. 相似文献
99.
Liquid Crystals: Liquid‐Crystalline Electrolytes for Lithium‐Ion Batteries: Ordered Assemblies of a Mesogen‐Containing Carbonate and a Lithium Salt (Adv. Funct. Mater. 8/2015) 下载免费PDF全文
100.
Hiromi Nakano Motohiro Yamada Masahiro Fukumoto Eiji Yamaguchi 《Journal of Thermal Spray Technology》2011,20(3):407-411
Cold spraying has been developed as a high-quality coating technique. In this article, copper is deposited on an AlN substrate
coated by the sputtering of titanium and copper at a low pressure of less than 1.0 MPa, making this approach suitable for
a wide range of engineering applications. In order to understand the adhesion mechanism at the atomic scale, the interfacial
regions are carefully observed in thin foil samples from the cross sections of the specimens with a HREM. We find a unique
wavy boundary between the sputtered titanium and the sputtered copper. It is assumed that the shear-instability phenomenon
occurs due to the cold-spraying process and influences the adhesive strength. Furthermore, the cold-sprayed copper particles
are connected directly without any oxidation layer due to the appearance of new metallic surfaces during the impact process.
The TEM data clearly reveal the phenomena and mechanisms related to the impact of powder sprayed on the substrate. 相似文献