• 대한화장품학회지
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• 제39권1호
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• pp.25-30
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• 2013

단백질을 연결시키는 효소인 transglutaminase는 모발에서 다양한 효과를 나타낼 수 있는 가능성이 있는데 이중에는 모발의 단단함을 증가시키는 작용도 포함된다. 여러 transglutaminase 효소 중 Streptomyces mobaraensis로부터 분리된 미생물 유래 효소를 손상된 모발에 사용한 후 인장강도를 평가한 결과 초기에 비해 15.64%까지 증가되는 것이 확인되었다. 이러한 효과는 transglutaminas가 샴푸를 사용하여 세정하는 과정에서의 모발 손상을 복구시킬 수 있다는 것을 의미한다. 또한 transglutaminase를 이용해 모발 표면의 특성을 개선 시킴으로써 모발의 윤기를 증가시키고 표면의 마찰력을 감소시키는데 유용하게 이용될 수 있었다.

• Computers and Concrete
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• 제21권6호
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• pp.681-695
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• 2018

This pioneer study investigates the size effect on the compressive and tensile strengths of fiber-reinforced self-compacting concrete (FR-SCC) with different specimens, before and after exposure to elevated temperatures. 432 self-compacting concrete (SCC) specimens with two concrete grades (50 and 80MPa) and three steel fiber ratios (0%, 0.5% and 1%) were prepared and tested. Moreover, based on the experimental results, new formulations were proposed to predict the residual strengths for different specimens. A parametric study was also carried out to investigate the accuracy of proposed formulations. Residual strength results showed that the cylinder specimen with dimensions of $100{\times}200mm$ was the most affected, while the cube with a size of 100 mm maintained a constant difference with the standard cylinder ($150{\times}300mm$). Temperature effect on the cube specimen (150 mm) was the least in comparison to other specimen sizes and types. In general, provision of steel fibers in SCC mixtures resulted in a reduction in temperature effect on the variance of a conversion factor. Parametric study results confirm that the proposed numerical models are safe to be used for all types of SCC specimens.

• 한국염색가공학회지
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• 제33권1호
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• pp.24-30
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• 2021

In this study, PET containing 3% silver ion-exchange zeolite was mixed with cotton in a ratio of 6:4 to prepare a spun yarn to evaluate the tensile strength, absorption speed, absorption rate, antibacterial property, and the efficiency of deodorization. As a result, the following conclusions were obtained. First, it can be confirmed that silver ion exchange zeolite is evenly distributed inside and on the surface of the antimicrobial PET-SF through SEM. It was found that the tensile strength between the CVC sample mixed with silver ion zeolite PET and cotton and the normal cotton 100% sample was slightly lower in the CVC sample. Although the absorption speed and water absorption rate were measured to find out the moisture characteristics, it was confirmed that there was no significant difference. The contact angle was slightly larger in the antimicrobial CVC sample, but the time it took for the moisture to completely penetrate into the knit fabric was 0.85 seconds. In addition, it was found that out of the total mixing ratio, 40% of antibacterial PET was spun with regular cotton to produce yarn, which had an excellent bacteria reduction rate of 99.9% and a deodorization efficiency of 85%.

• 한국건설순환자원학회논문집
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• 제5권2호
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• pp.91-96
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• 2010

본 논문에서는 일반 보행자 도로의 형태 및 문제점을 찾아보고 공원 산책로 및 관광지의 보도 등과 같은 일반적인 보도용 포장체에 Wood Chip과 바인더로써 우레탄 수지를 사용하여 새로운 형태의 자원순환형 보도 포장체의 물성에 관한 연구를 실시하였다. 포장재의 물성실험은 인장강도 시험, 투수성 시험, 탄력성 시험, 침수후의 인장강도 변화 등을 실시하였고, 또한 2.5~5mm 크기의 잔골재를 사용한 효과에 대해서도 검토하였다. 인장강도 시험은 침수전과 침수후로 나누어 시험하였으며 침수전 1.06MPa, 침수후 0.67MPa의 인장강도를 나타내 36.8%의 인장강도 감소율을 나타내었다. 투수성 시험은 투수성 포장체의 현장 투수시험 방법에 의거해 실험하였으며 시험 결과 투수계수는 0.67~0.78mm/s의 값으로 모두 0.1mm/s 의 목표투수계수를 초과하였다. 탄력성 시험은 일본 도로협회의 탄력성시험방법에 따라 실시하였으며 GB계수 21%, SB계수 10%의 값을 나타냈고 잔골재의 양이 증가할수록 GB계수, SB계수 모두 점차 증가하는 경향을 나타냈었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.301-301
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• 2003

In current study, Nanocomposites are reinforced with carbon nanofiber, carbon nanotube and SiC, etc. Since the nano reinforcements have the excellent mechanical, thermal and electrical properties compared with that of existing composites, it has lately attracted considerable attention in the various areas. Cu have been widely used as signal transmission materials for electrical electronic components owing to its high electrical conductivity. However, it's size have been limited to small ones due to its poor mechanical properties. Until now, strengthening of the copper alloy was obtained either by the solid solution and precipitation hardening by adding alloy elements or the work hardening by deformation process. Adding the alloy elements lead to reduction of electrical conductivity. In this aspect, if carbon nanofiber is used as reinforcement which have outstanding mechanical strength and electric conductivity, it is possible to develope Cu matrix nanocomposite having almost no loss of electric conductivity. It is expected to be innovative in electric conducting material market. The unidirectional alignment of carbon nanofiber is the most challenging task developing the cooer matrix composites of high strength and electric conductivity. In this study, the unidirectional alignment of carbon nanofibers which is used reinforced material are controlled by drawing process and align mechanism as well as optimized drawing process parameter are verified via numerical analysis. The materials used in this study were pure copper and the nanofibers of 150nm in diameter and of 10∼20$\mu\textrm{m}$ in length. The materials have been tested and the tensile strength was 75MPa with the elongation of 44% for the copper. it is assumed that carbon nanofiber behave like porous elasto-plastic materials. Compaction test was conducted to obtain constitutive properties of carbon nanofiber Optimal parameter for drawing process was obtained by analytical and numerical analysis considering the various drawing angles, reduction areas, friction coefficient, etc. The lower drawing angles and lower reduction areas provides the less rupture of co tube is noticed during the drawing process and the better alignment of carbon nanofiber is obtained.

• 펄프종이기술
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• 제45권6호
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• pp.24-29
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• 2013

In this study, we investigated the applicability of PCC(precipitated calcium carbonate) as a raw material for the manufacture of duplex-board. Papers were made with white-ledger stock collected from the actual duplex-board mill and PCC in a laboratory, and paper properties including bulk, ash content, tensile strength, burst strength, brightness and opacity were measured. The effect of PCC on the drying energy of duplex-board was also determined by measuring the moisture content of wet web and calculating drying energy reduction. PCC increased bulk and ISO brightness significantly, which means PCC can decrease the use of virgin pulp and recycled fibers. PCC decreased the moisture content of wet web, which means PCC can decrease drying energy consumption. However, paper strength decreased as addition levels of PCC addition increased. Therefore, the addition level of PCC must be determined considering the reduction of paper strengths.

• Steel and Composite Structures
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• 제14권1호
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• pp.41-55
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• 2013

Fiber reinforced polymers (FRP) materials are increasingly being used for strengthening and repair of steel structures. An issue that concerns engineers in steel members which are retrofitted with FRP is stress experienced due to temperature changes. The changing temperature affects the interface bond between the FRP and Steel. This research focused on the effects of cyclical thermal loadings on the interface properties of FRP bounded to steel members. Over fifty tests were conducted to investigate the thermal effects on bonding between FRP and steel, which were cycled from temperature of $-11^{\circ}C$ ($12^{\circ}F$) to $60^{\circ}C$ ($140^{\circ}F$) for 21-36 days. This investigation consisted of two test protocols, 1) the tensile test of epoxy resin, tack coat, FRP and FRP-steel plate, 2) tensile test of each FRP compound and FRP with steel after going through thermal cyclic loading. This investigation reveals an extensive reduction in the composite's strength.

• Journal of Welding and Joining
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• 제32권4호
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• pp.75-79
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• 2014

This paper has an aim to study the effect of PWHT(for 140min. at $600^{\circ}C$) on FCAW weld metal properties (tensile, charpy impact and CTOD value) of YS 460 MPa steels for ship and offshore structures. On the basis of these study, it was found that strength was decreased and elongation was increased by PWHT. These phenomenon resulted from the reduction of acicula ferrite volume fraction by grain growth. Also, Charpy impact and CTOD value were decreased by PWHT. These phenomenon resulted from grain growth. Because the grain boundary grown by PWHT can play a role as crack initiation site and make the crack propagate more easily. Although weld metal properties were decreased by PWHT, tensile and impact properties could meet the class societies requirements for welds of YS 460 MPa steel, but decrease of fracture toughness need to be consider seriously.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.151-158
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• 2005

For the safety analysis of large structures such as nuclear containment buildings, we conventionally prefer to use analytical approach using finite element method rather than empirical test. Therefor, this paper is mainly focused to develop low-order solid finite element model with the elasto-plastic material model for the safety analysis of nuclear containment building. Drucker-Prager failure criteria in uncracked concrete and maximum tensile stress criteria in cracked concrete are used to model the constitutive behavior of concrete. The concrete material model takes into account the aspects of tensile strain, compression strength reduction of concrete and shear transfer to improve the accuracy of the finite element analysis. Finally, numerical simulation to compare the performance of the developed model with experimental results is employed. The numerical results in this study agree very well with the experimental data.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.233-237
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• 2003

For Taejon LNG Pilot Cavern being constructed to verify the technical aspects for storing LNG in lined rock cavern, various numerical studies were carried out to estimate the temperature profile and to understand thermo-mechanical behaviour in the rock around the cavern. With the help of Claesson's analytical solution and numerical models, the extent of zero degree isotherm and possible boil-off rate of gas to be stored were estimated. Even though the tensile stress by cooling down is very large compared to the tensile strength of the rock, it has been shown that possible rock yielding might bring about the dramatic reduction of the stress.