• 한국염색가공학회지
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• 제4권3호
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• pp.82-90
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• 1992

To optimize the foam dyeing procedures for polyester and polyester/nylon blended non-woven fabrics, the effects of organic solvents and surfactants were investigated by measuring the foam heights and surface tensions of the foam dyeing solution. The results of the experiments can be summarized as follows: 1) Organic solvents and surfactants (sodium lauryl sulphate: SLS) solution lower the surface tension (ST) of the water, but ST lowering rate of SLS solution is greater than that of solvents. For a 0.25% SLS solution, the minimum surface tension was 30.3 dyne/cm, which is nearly the same value for organic solvents. 2) For 0.25% SLS solutions, additional adding of a 4.0% organic solvent makes the foam height (FH) be its maximum. 3) At 0.6 g/ι dye concentration, incorporation of 0.4% SLS makes the surface tension of the foam solution be its minimum. The foam height did not show any trend due to the dye type. 4) The effect of foam stabilizers (sodium alginate (Alg-Na) and hydroxy ethyl cellulose (HEC)) were also investigated. The foam height of the foaming solution with HEC was greater than that with Alg-Na. The foam stability of the foaming solution with Alg-Na was better than that with HEC.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.860-865
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• 2000

This Paper Proposes the test pieces of X, Y and Z axes to compensate the shape distortion of Selective Laser Sintering(SLS) parts resulting from the phase change during the sintering process. In no case of the proposed compensation test pieces of X, Y axes the accurate rates of shrinkage can be measured with the reduction of curling which is obtained from adjustment of build orientation and the formula used to get scale factors are proposed with the shrinkage rates of them. The scale factors of X, Y and Z axes are generated by building up proposed compensation test pieces. The generated scale iactors are required to satisfy the dimensional accuracy even if there are changes of the build position and the size of SLS parts in the build chamber. For this reason, it is proposed that the build positions and the size be considered to be noise factors against the compensation test pieces and a method is also proposed that scale factors be selected to robustly maintain the dimensional accuracy of SLS parts under the actual operating conditions with the application of the Taguchi Method.

• 약학회지
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• 제46권2호
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• pp.102-107
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• 2002

The particle size of medicinal materials is an important physical property which affects the pharmaceutical behaviors such as dissolution, chemical stability, compressibility and bioavailability of solid dosage forms. The size reduction of raw pharmaceutical powder is needed to formulize insoluble drugs or slightly soluble drugs and to improve the pharmaceutical properties such as the solubility, the pharmaceutical mixing and the dispersion. The objective of the present study is to evaluate the grinding characteristics of ursodeoxycholic acid(UDCA) as a model of insoluble drugs. The effects of the grinding time and the amount of additive on particle size distribution of ground UDCA were investigated. Grinding of insoluble drug, UDCA and a series of dry co-grinding experiments of UDCA with sodium lauryl sulfate(SLS) as an additive were carried out using a planetary ball mill. It was measured that the median diameter and the particle size distribution of ground products with grinding UDCA and additive SLS by Mastersizer. As a result of co-grinding of UDCA and SLS, the particle size of co-grinding products was decreased more than single grinding one. However, it was observed that co-grinding products were reaggregated to larger particles after 120 min.

• 국제강구조저널
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• 제18권4호
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• pp.1397-1409
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• 2018

Stiffened plates with high slenderness parameters show large out-of-plane deflections, due to elastic buckling, which may occur before the plates reach their ultimate strength. From a serviceability point of view, restriction of out-of-plane deflections exceeding the fabrication tolerance is of primary importance. Compressive strength at the serviceability limit state (SLS) for slender stiffened plates under uniaxial stress was investigated through nonlinear elasto-plastic finite element analysis, considering both geometric and material nonlinearity. Both normal and high-performance steel were considered in the study. The SLS was defined based on a deflection limit and an elastic buckling strength. Probabilistic distributions of the SLS strengths were obtained through Monte Carlo simulations, in association with the response surface method. On the basis of the obtained statistical distributions, partial safety factors were proposed for SLS. Comparisons with the ultimate strength of different design codes e.g. Japanese Code, AASHTO, and Canadian Code indicate that AASHTO and Canadian Code provide significantly conservative design, while Japanese Code matches well with a 5% non-exceedance probability for compressive strength at SLS.

• 한국분말재료학회지
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• 제30권1호
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• pp.7-12
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• 2023

Metal-additive manufacturing techniques, such as selective laser sintering (SLS), are increasingly utilized for new biomaterials, such as cobalt-chrome (Co-Cr). In this study, Co-Cr gas-atomized powders are used as charge materials for the SLS process. The aim is to understand the consolidation of Co-Cr alloy powder and characterization of samples sintered using SLS under various conditions. The results clearly suggest that besides the matrix phase, the second phase, which is attributed to pores and oxidation particles, is observed in the sintered specimens. The as-built samples exhibit completely different microstructural features compared with the casting or wrought products reported in the literature. The microstructure reveals melt pools, which represent the characteristics of the scanning direction, in particular, or of the SLS conditions, in general. It also exposes extremely fine grain sizes inside the melt pools, resulting in an enhancement in the hardness of the as-built products. Thus, the hardness values of the samples prepared by SLS under all parameter conditions used in this study are evidently higher than those of the casting products.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.509-512
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• 2006

In this paper, we proposed the novel device and process design to enhance the uniformity of low-temperature poly-Si TFTs fabricated by sequential lateral solidification (SLS). The proposed design schemes can avert the conventional two-shot SLS process-induced issues. Moreover, different design considerations between conventional excimer laser crystallization and the SLS process were also proposed and discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.221-222
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• 2007

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1404-1409
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• 2007

Polymers for laser sintering were needed in order to fabricate the articles with the three-dimensional duplication equipment of SLS (selective laser sintering) process. The thermal properties, particle size, distribution, and shape of polymer powder had a close relation with the processibility of laser sintering. In this study, we prepared new polymer powders with uniform size and higher bulk density by wet process. Wet process consists of several finely-controlled steps such as dissolution, nucleation, propagation and crystallization. Several additives were added to improve the thermal, rheological, and flow properties.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1756-1760
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• 2006

LTPS technology based on SLS Crystallization was intensively reviewed. LTPS structure produced by SLS crystallization is composed of much larger grains compared with conventional ELA crystallization structure, which can give higher TFT performances. However, TFT performance uniformity and anisotropy problem should be solved for it to be used in mass production. TFT performance uniformity was from main grain boundary position and could be solved by equal defect area structure $(EDAS^{TM})$. TFT performance anisotropy could be also solved by multi-channel (MC) structure that can make parallel component in perpendicular channel direction. The higher TFT performances from SLS technology can make superior optical and/or electrical properties and has been adopted in mass production successfully.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.673-674
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• 2003

The reliability of TFT, crystallized by sequential lateral solidification (SLS) technology, has been studied High current damage is characterized by high gate bias (-20V) and drain bias (-10V). It is found that performance of SLS TFTs is enhanced by high current stress up to 300 sec of stress time for 20/8 (W/L) N-TFT. After that, TFT performance is degraded with the increase of the stress time. It is speculated from the experimental data that SLS TFTs initially contain a number of unstable defect states. Then, the defect states seem to be cured by high current stress.