• The Korean Journal of Ecology
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• 제24권2호
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• pp.121-123
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• 2001

Gums, resins and gum-resins represent a variety of plant exudates that are highly prized and are extensively used in various industries. The usage of water soluble gums is growing at faster rate as they are excellent suspending agents, dispersants stabilizing agents, emulsifiers and gel forming agents. The gums are made up of carbohydrate polymers, composed of sugar units glycosidically condensed to form large molecules. Resins are non-volatile products, and oxidative products of terpenes or fatty acids, and are of greater commercial importance. They are soluble in water and contrasted with gums, soluble in organic solvents only.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.166.4-166
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• 2001

The oscillation of a crane system is divided into the oscillation of container in respect of its trolley and the oscillation of trolley in relation to the whole crane system. We introduce a new type of crane system that avoids to the irreducible sway of crane system caused by hanging cables. The cables suspending the spreader are replaced by using an "anti-sway system". The proposed system is composed of mechanical arms with function of anti-sway based on conventional line system. The effectiveness of the proposed new type crane system and the controller is shown through the simulation results.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.862-868
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• 2008

Many studies have been conducted to increase heat transfer in fluid. One of the various heat transfer enhancement techniques is suspending fine metallic or nonmetallic solid powder in traditional fluid. Nanofluid is defined as a new kind of heat transfer fluid containing a very small quantity of nanometer particles that are uniformly and stably suspended in a liquid. This study investigates the effect of nanofluid containing diamond, CuNi and CuAg nanometer particles, and proposes the heat transport mechanism of nanofluid. The test result shows that the thermal conductivity of nanofluid is much higher than that of traditional fluid, and the increasing rate of the conductivity is dependent on the conductivity of the solid metal.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.188-193
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• 2012

Recently, the nanofluid which is stably dispersing or suspending of nanoparticles in the conventional heat transfer fluids (HTF) such as water and ethylene glycol has attracted significant interests as a solar thermal energy absorbing medium because they have excellent absorption and thermophysical properties compared to the typical HTF. In the present study, the efficiency of nanofluid-based flat-plate solar collector is analytically evaluated using the theoretical model of energy balance equation. The theoretical model considers the incoming solar radiation as a volumetric heat generation and the water-based single wall carbon nanohorn(SWCNH) nanofluid is used as a solar energy absorbing medium. Finally, the efficiency of nanofluid-based collector is calculated according to the volume fraction of SWCNH using the analytical solution.

• 소성∙가공
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• 제11권7호
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• pp.575-580
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• 2002

To evaluate elastic and micro-failure properties of MEMS materials, the electro-statically operated test devices were designed and fabricated by micro machining technology. The test structures consist or comb drives for loading and suspending beams in testing. From the analysis of beam displacement based on elastic beam theory, elastic modulus and yield strength of Al film were measured. And, by introducing the micro notch and cyclic loading, the micro-failure was Induced and the micro-fracture toughness of Si film was evaluated. Moreover, the cycles to failure were estimated from the degradation of resonant frequency. Finally, the effects of notch on micro failure were discussed.

• 한국생산제조학회지
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• 제21권1호
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• pp.156-160
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• 2012

Recently WCDMA signal transmission technology by large output microwave antenna have showed reduction of human resources and operating expense. But the existing antenna brackets cost is very expensive also its structure and functions are complicated. Unit brackets, suspending some sensors, subjected to acceleration loads, often fail due to self-vibration. To prevent such failures, it is necessary to understand the fatigue failure mode and to evaluate the fatigue life using tests or analysis techniques. The objective of this study is to develop the component test specifications, which are applicable to predict fatigue life at initial product design step, for unit brackets using vibration fatigue technique. So its application is limited to installation and management. In this project, we studied about more convenient bracket for microwave antennas through improvement on the existing antenna bracket's shortcoming and could develop an improved universal antenna bracket system for simple installation and application.

• 전기학회논문지
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• 제61권5호
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• pp.690-697
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• 2012

Novel 8/10 bearingless switched reluctance motor, which can control rotor radial positions with magnetic force, is proposed. The motor has combined characteristics of switched reluctance motor and magnetic bearing. This paper proposes a air-gap control system method of suspending force control in a bearingless switched reluctance motor (BLSRM). The proposed radial force control scheme is independent to the torque winding current. A PI direct current control (DCC) controller and look-up table are used to maintain a constant rotor air-gap. From the analysis and the experimental results, it is shown that the proposed strategy is effective in realizing a naturally decoupled radial force control of BLSRM.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.503-506
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• 2000

YBCO superconducting thick films were prepared on Ag wire by electrophoresis in acetone and ethanol with chemically modified suspension. The addition of organic compounds, such as PEG, EG into suspension solution for improving critical current density was investigated. Surface state, deposition condition, pore distribution and cracks were investigated by using SEM photographs. Controlling preparation conditions were studied for reducing these defects. As a results, in acetone solution, the surface crack of samples was decreased with increasing PEG. On the contrary, the surface crack of sample was increasing with increasing the amount of EG. In ethanol solution without I$_2$, which was generally used for an electrolyte, the deposition time was longer than this of acetone. For that reason the sample deposition in ethanol time was needed with enough stirring time for suspending YBCO powder and deposition time.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.366-367
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• 2006

Carbon nanotubes (CNTs) have attracted remarkable attention as reinforcement for composites owing to their outstanding mechanical properties. The CNT/Cu nanocomposite is fabricated by a novel fabrication process named molecular level process. The novel process for fabricating CNT/Cu composite powders involves suspending CNTs in a solvent by surface functionalization, mixing Cu ions with CNT suspension, drying, calcination and reduction. The molecular level process produces CNT/Cu composite powders whereby the CNTs are homogeneously implanted within Cu powders. The mechanical properties of CNT/Cu nanocomposite, consolidated by spark plasma sintering of CNT/Cu composite powders, shows about 3 times higher strength and 2 times higher Young's modulus than those of Cu matrix.

• Journal of Pharmaceutical Investigation
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• 제4권4호
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• pp.38-45
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• 1974

Sulfur had been used for the medical fields as fungacidal bacteriocides and gelatolytic agent from ancient B. C 700, their prepartiones contained the sulfur are restrict to freely medication, the restrutive reasones are the it's preparation stabilized sparing solubility, and limit to pharmaceutical development of colloidal sulfur-self. Anthors prepared white lotion, registered on U.S.P XIII from the colloidal sulfur, by the method midified buku zawa make the stabilized lotion by the various fatty alkyl sulfates, and the result obtained are as follows the suspending agents for stabilize to the colloidal sulfur are the fatty alcohol sulfates than natural clay on the imbibition appeareuce and usefulnss. The adequate quantities of stearic acid in lotion base are $1.5{\sim}2.0$ percent for refluidity and pourability. The carbon numbers in alkyl radical used fatty alcohol sulfates as anionic surfactants are maxture of $12{\sim}18$ about efficiency, as possible as, the electrolyte is removed from the white lotion.