• 한국정밀공학회지
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• 제28권2호
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• pp.193-201
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• 2011

Clamp type transferring mechanism for package substrate's wet processes was newly developed instead of conventional roller type transferring mechanism. Clamp type transferring mechanism has the advantages of reducing the panel deflection and of minimizing the contact problem between the panel and the transferring mechanism. Individual clamp of the mechanism has two distinct mechanical functions which are perfectly fixing a panel during the transferring and generating adequate tension for the panel. To determine the mechanical parameters of the clamp, panel deflection simulation was conducted and the result was verified by the panel deflection measurement. Also, fixing angle of a clamp could be determined by the free body force analysis of individual clamp. Finally clamp type transferring mechanism was actually manufactured and the transferring performance was verified during the water spraying condition of the package substrate's wet processes.

• 대한화장품학회지
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• 제14권1호
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• pp.16-37
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• 1988

A new quaternary ammonium compound, hydrolyzed ginseng-sapoin quaternary (HGSQ), from hydrolyzed Korean ginseng-saponin and 2, 3-epoxypropyltrimethyl ammonium chloride has been developed as a conditioning agent for hair care products. This structure has the hydrophilic group from the introduced cationic and the hydrophobic group from the aglycone of ginseng saponin. Its properties: surface tension, conductivity, critical micelle concentration, eye irritation, sorption onto hair, force reduction (%) for 20% extension and moisture retention effect comparing with the commercial standards. Also half-head tests of HGSQ-containing shampoo were carried out to compare the conditioning effects in shampoos.

• 한국세라믹학회지
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• 제54권6호
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• pp.478-483
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• 2017

The advantage of ceramic ink-jet printing technology is the accurate and fast printing process of digital images for various products. For digital ink-jet printing applications, ceramic ink requires proper viscosity and surface tension, along with dispersion stability of the inorganic pigments. The purpose of this study is the formulation of an environment-friendly ceramic ink with a water-based system; using nano-sized $CoAl_2O_4$ pigment as a raw material, ink should have dispersion stability to prevent nozzle clogging during ink-jet printing process. In addition, the surface tension of the ceramic ink was optimized with the polysiloxane surfactant according to the surface tension requirement (20 - 45 mN/m) for ceramic ink-jet printing; by adjusting the viscosity with poly ethylene oxide, jetting behavior of the ceramic ink was investigated according to changes in the physical features through drop watcher measurement.

• 한국초전도ㆍ저온공학회논문지
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• 제19권4호
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• pp.26-30
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• 2017

The promising characteristics of 2G high-temperature superconductor (HTS) coated conductor (CC) tapes have made it possible to apply to various electrical device applications. In this study, the mechanical and electromechanical properties of Sn-Cu double layer stabilized GdBCO CC tapes have been characterized. The stress and strain tolerances of $I_c$ in GdBCO CC tapes adopting stainless steel substrate were evaluated using $I_c$-strain measurement at 77 K under both uniaxial tension and monotonic bending conditions. The results were compared to the conventional single Cu layer stabilized CC tape. As a result, the Sn-Cu double layer stabilized GdBCO CC tapes showed somehow lower or comparable electromechanical properties as compared to the Cu stabilized CC tape ones.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2648-2653
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• 2007

Recently, increasing demand on not only lighter but also extremely mobile battery make micro fuel cell device very attractive alternative. By reducing the size of fuel cell, surface tension becomes dominant factor with minor gravitational effect. Therefore, it is very difficult to detach the $CO_2$ bubble generating on a cathode side in ${\mu}DMFC$ (micro direct methanol fuel cell). The degassing of a $CO_2$ bubble has drawn quite attention especially for ${\mu}DMFC$ due to its considerable effect on overall machine performance. Our attention has been paid to the dynamic behavior of immiscible bubble attached to the one side of the wall on 2D rectangular channel subject to external shear flow. We use Level Contour Reconstruction Method (LCRM) which is simplified version of front tracking method to track the bubble interface motion. Effects of Reynolds number, Weber number, advancing/receding contact angle and property ratio on bubble detachment characteristic has been numerically identified.

• 접착 및 계면
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• 제3권3호
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• pp.7-14
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• 2002

Poly(ethylene-co-methylacrylate)(PEMA)를 KOH, 암모니아 수용액으로 가수분해, ammonolysis 시켜서 측기에 -COOK, $-CONH_2$, -COOH를 갖는 수분산 형태의 변성 폴리에틸렌(m-PE)을 제조하였다. Infrared spectroscopy, 원소 분석 및 atomic absorption 분석 등을 통하여 m-PE 측기의 종류 및 조성비를 조사하였으며 수분산액의 고형분 함량에 따른 점도 및 표면장력을 측정하였다. 제조된 수분산액은 측기의 조성에 따라 안정도, 투명도 등이 변화하였다. 측기 중에서 -COOK가 수분산에 가장 큰 영향을 주었으며 -COOK 조성비가 20 mol% 이상이 되어야 안정한 분산을 얻을 수 있었고 또한 -COOK 조성비가 높을수록 수분산액은 투명하였다. 동일 -COOK 조성비에서는 아마이드의 농도가 높을수록 탁도가 증가하여 친수성이 떨어짐을 알 수 있었다. 분산액의 고형분 함량에 따른 점도를 측정하면 -COOK 조성비가 클 경우 낮은 고형분 함량에서 급격한 점도 증가가 일어나 고분자 사슬사이의 얽힘이 쉽게 일어남을 알 수 있으며 표면장력은 -COOK 조성비가 클 경우 작은 값을 나타내었다.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 KSOT/KEMS Fall Annual Meeting
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• pp.100-100
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• 2004

• 한국전산유체공학회지
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• 제12권3호
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• pp.41-46
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• 2007

Dynamic behavior of immiscible gas bubble attached to the wall in channel flow plays very important role in many engineering applications. Special attention has been paid to micro direct methanol fuel cell(${\mu}$DMFC) where surface tension becomes dominant factor with minor gravitational effect due to its reduced size. Therefore, displacement of $CO_2$ bubble generating on a cathode side in ${\mu}$DMFC can be very difficult and efficient removal of $CO_2$ bubbles will affect the overall machine performance considerably. We have focused our efforts on studying the dynamic behavior of immiscible bubble attached to the one side of the wall on 2D rectangular channel subject to external shear flow. We used Level Contour Reconstruction Method(LCRM) which is the simplified version of front tracking method to track the bubble interface motion. Effects of Reynolds number, Weber number, advancing/receding contact angle and property ratio on bubble detachment characteristic has been numerically identified.

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.338-346
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• 2019

During last years, hydrogen refueling infrastructure test and devices research for hydrogen station presented a significant growth consisting of the commercialization of fuel cell electric vehicles (FCEVs). However, we still have many challenges for making commercial hydrogen stations such as increased safety and cost reduction. This study demonstrates the low cost hydrogen storage tank (type 2) and effective winding method for high pressure hydrogen storage. We use numerical analysis to verify stress changes inside the wire according to the winding condition. Also liner size, winding wire size and wire tension were studied for the safety and cost down. Results show that the stress of winding wire decreased with increased winding angle and increased the liner diameter. On the other hand, the stress of winding wire increased according to the increased wire thickness and tension.

• Design & Manufacturing
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• 제8권2호
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• pp.50-55
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• 2014

Recently, semi-stack mold have been developed for satisfying the various elements required in the mold industry. The mold is possible using with general-purpose injection molding machine by weight reduction through the improvement of the mold structure. In order to do that, tension core, spiral cooling system and half runner system were applied. It is effective for increased productivity and decreased of loss to the materials. However, the mold is required the filling balance in order to improve the quality and efficiency. Thus this study performed that optimum design and analysis of semi-stack mold for filling balance.