• 한국의류학회지
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• 제11권3호
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• pp.57-65
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• 1987

The purpose of this study was to investigate the optimum treatment [condition for the Durable press finish of viscose rayon fabrics. Three types of commercial N-methylol crosslinking agents were applied to the fabric utilizing the pad-dry-cure technique. Changes in physical properties were evaluated for the various resin and catalyst concentrations. For DMU, the effect of different catalysts, $MgCl_2$ and $NH_4Cl$, were also compared. DMU treated fabrics showed in crease recovery angle, tensile strength and tearing strength but drastic decrease in abrasion resistance. DMDHEU and MDMDHEU treated fabrics were similar in most physical properties. However, DMDHEU treated fabrics were better in crease recovery angle and stiffness, and MDMDHEU treated fabrics were better in tensile strength, tearing strength and abrasion resistance. For a given resin system, crease recovery angle, tensile strength and stiffness increased with a increase in resin concentration. Tearing strength showed very little change, while abrasion resistance was decreased significantly as the crease recovery angle was increased. For the treatment of DMU, $MgCl_2$ catalyst was much better than $NH_4Cl$ in all physical properties. When $NH_4Cl$ catalyst was used, strength reduction and discoloration were observed. As the catalyst concentration increased, crease recovery angle, stiffness were increased. Tensile strength and tearing strength were increcased than control but at high catalyst concentration, the strength were decreased and abrasion resistance was significantly lowered. DMDHEU and MDMDHEU were more sensitive to catalyst concentrations than DMU.

• 한국해양환경ㆍ에너지학회지
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• 제19권4호
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• pp.247-258
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• 2016

황해 태안반도 남서부 해역 8개 정점에서 해양퇴적물을 채취하여 퇴적물의 지음향 및 물리적 특성을 파악하였다. 전반적으로 사질 퇴적물이 우세하며 연구지역의 사질 퇴적물은 최대빙하기(LGM)이후 해수면 변동의 영향을 받아 연구지역에 퇴적되었다. 이후 금강 및 인근 연안에서 유입된 세립질퇴적물의 영향을 받은 지역은 니질 사 또는 사질 니가 발달했다. 이러한 퇴적 환경의 영향으로 정점별로 퇴적물 조직특성, 물리적 성질, 음파전달속도의 수평 수직적 차이가 나타난다. 음파전달속도, 평균입도 및 물리적 성질간의 상관관계를 보면 비교모델로 사용한 남해 퇴적물과 전반적으로 유사한 경향을 보이나 절대값에서 차이를 보인다. 이러한 차이는 퇴적환경, 광물조성 및 측정 시스템의 차이에 의한 것으로 사료된다.

• 한국염색가공학회지
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• 제33권3호
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• pp.120-130
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• 2021

The condition of covering process using thermoplastic polyetherester elastomeric fibers(TPEE) was established. Two types of core yarn(TPEE, Spandex) and one type of effect yarn(PET) were used as materials to confirm the change in physical properties of covering yarn under various covering conditions. In addition, the effects of the treatment temperature on the elongation at break of covering yarn after heat treatment was analyzed. Through this analysis, it was confirmed that the elastic recovery of TPEE which is used as the core yarn was increased with the draw ratio, but decreases when it exceeds 1:2.5. And the elongation at break of the covering yarn could be increased by increasing the twist per meter of it. Additionally, it was confirmed that the elastic recovery of TPEE which is used as a core yarn, could be increased by applying heat treatment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.63-64
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• 2021

In this study, Coal gasification slag(CGS) was replaced with fine aggregate to verify the physical properties of the concrete according to the change in cement types. As a result of the study, the use of CGS resulted in a decrease of superplasticizer and an decrease of AE agent. In addition, when 50% of mixed cement and CGS were replaced, the initial strength expression was delayed, and the strength enhancing effect was judged to be weak.

• 생물환경조절학회지
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• 제7권3호
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• pp.214-218
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• 1998

저밀도 에너지를 효율적으로 축열하기 위해서 현열축열재보다는 상변화 온도 3$0^{\circ}C$ 수준의 잠열축열재를 이용하는 것이 효과적이다. 이를 위하여 연구를 수행한 결과, SCD에 APS를 0.0~5.0wt% 첨가하여 과냉도를 25.$0^{\circ}C$에서 $1.5^{\circ}C$ 이하로 조절하였으며, APS의 적정 함량은 3.0wt%였다. SCD에 PSC를 0.0~3.0wt% 첨가하여 상분리량을 70.0%에서 0.0%로 조절하였으며, PSC의 적정 함량은 1.5wt%였다. 축열재 내구성 검증을 위하여 0~1,500회의 상변화 사이클을 수행한 결과 상변화 온도의 변화량이 30$\pm$l.$0^{\circ}C$ 이하, 잠열량 변화가 54$\pm$2.0 Kcal .kg-1 이하로 안정된 값을 보였다. 따라서 축열재의 수명은 10년 정도 보장될 수 있는 것으로 판단되었다

• Geomechanics and Engineering
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• 제14권1호
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• pp.99-105
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• 2018

Soils are generally classified as fine-grained or coarse-grained depending on the percentage content of the primary constituents. In reality, soils are actually made up of mixed and composite constituents. Soils primarily classified as fine-grained, still consists of a range of coarse particles as secondary constituents in between 0% to 50%. A laboratory scale model test was conducted to investigate the influence of coarse particles on the physical (e.g., density, water content, and void ratio) and mechanical (e.g., quick undrained shear strength) properties of primarily classified fine-grained cohesive soils. Pure kaolinite clay and sand-mixed kaolinite soil (e.g., sand content: 10%, 20%, and 30%) having various water contents (60%, 65%, and 70%) were preconsolidated at different stress levels (0, 13, 17.5, 22 kPa). The quick undrained shear strength properties were determined using the conventional Static Cone Penetration Test (SCPT) method and the new Fall Cone Test (FCT) method. The corresponding void ratios and densities with respect to the quick undrained shear strength were also observed. Correlations of the physical properties and quick undrained shear strengths derived from the SCPT and FCT were also established. Comparison of results showed a significant relationship between the two methods. From the results of FCT and SCPT, there is a decreasing trend of quick undrained shear strength, strength increase ratio ($S_u/P_o$), and void ratio (e) as the sand content is increased. The quick undrained shear strength generally decreases with increased water content. For the same water content, increasing the sand content resulted to a decrease in quick undrained shear strength due to reduced adhesion, and also, resulted to an increase in density. Similarly, it is observed that the change in density is distinctively noticeable at sand content greater than 20%. However, for sand content lower than 10%, there is minimal change in density with respect to water content. In general, the results showed a decrease in quick undrained shear strength for soils with higher amounts of sand content. Therefore, as the soil adhesion is reduced, the cone penetration resistances of the FCT and SCPT reflects internal friction and density of sand in the total shear strength.

• 통합자연과학논문집
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• 제7권1호
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• pp.5-10
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• 2014

A study that copolymerized Ag nanoparticle and furfuryl isocyanate with the crosslinking agent EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), MA (methacrylic acid) and the initiating agent AIBN (azobisisobutyronitrile) is presented. Measurement of the physical characteristics of the produced macromolecule showed that the water content is 32.08~32.67%, refractive index 1.446~1.448, visible light transparency 83.2~67.6%, contact angle $68.2{\sim}83.5^{\circ}$ and tensile strength 0.541~0.755 kgf. It is also demonstrated that the addition of Ag nanoparticles is associated with the reduction of UV-B transmittance and increase in tensile strength. The results show that the produced copolymer can be used as a material for ophthalmic lenses with durability and UV-blocking properties.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.777-780
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• 2004

Recently, the use of structure compound waterproof agent (hereinafter referred to as 'SCWA') that is used when manufacturing concrete for concrete structures, increases in quantity. However, while it is expected that the SCWA that is mixed in the concrete inside can significantly affect the change of physical properties that lift the internal force of a structure. This study has been conducted through an experiment for the effects of cement hardener on the formation of microscopic texture, and newly generated hydrates from that result were not confirmed in the. present experiment. It was found that at the hydrate reaction it has the property that can be hardened within the limit of pore diameterar a specific size rather than there is the internal gap filling capacity due to generating other hydrates.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.54-58
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• 1991

It is well known that metal cutting leaves a plastically deformed layer in the machined surface. This residual phenomenon affects in various forms the physical properties of machined components such as the fatigue strength, the dimensional instability, microcracks, and the stress corrosion cracking. These physical properties, so called surface integrity, are very important for designing highly stressed and critically loaded components. Typical plastic strains in the machined surface are very difficult to measure, since they are located within a very short distance from the surface and they change very rapidly. There is an alternative way to determine the residual strain in plastically deformed materials by measuring the grain size after a subsequent recrystallization process. Although, this technique has been successfully applied by several researchers to find the plastic zone around notches and cracks in various materials and welding beads, few works have been reported using the recrystallization method to determine the residual strains in machined surface. Therefore, the purpose of this investigation Is to explore the effectiveness of the recrystallization technique in machining applications, and in particular, to find the effect of cutting parameters, i.e., depth of cut and rake angle on the plastic strains.

• 한국정밀공학회지
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• 제15권4호
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• pp.141-147
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• 1998

A plastically deformed layer in the precision machined surface affects in various forms the physical properties of machined components such as the fatigue strength, the dimensional instability, microcracks and the stress corrosion cracking. These physical properties, so called surface integrity, are very important for designing highly stressed and critically loaded components. Typical plastic strains in the precision machined surface are very difficult to measure, since they are located within a very short distance from the surface and they change very rapidly. A new way is suggested to determine the residual strain in plastically deformed materials by analyzing the plastically deformed layer after a subsequent recrystallization process. This investigation is to explore a new technique for measuring plastic strain in machining applications, and in particular, to and the effect of cutting parameters(rake angle, depth of cut, specific cutting energy), on the plastic strains and strain energy.