• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.229-232
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• 2006

The HPFRCCs show that the multiple crack propagation, high tensile strength and ductility due to the interfacial bonding of the fibers to the cement matrix. Moreover, performance of cement composites varies according to type and weight contents of reinforcing fiber. and HPFRCCs with hybrid fiber have better performance than HPFRCCs with single fiber in damage tolerance. Total four cylindrical specimens were tested, and the main variables were the type and weight contents of fiber, which was polyvinylalchol (PVA), polyethylene (PE). In order to clarify effect of hybrid types on the characteristics of fracture and damage process in cement composites, AE method was performed to detect micro-cracking in HPFRCCs under cyclic compression. Loading conditions of the uniaxial compression test were monotonic and cyclic loading. And from AE parameter value, it is found that the second and third compressive load cycles resulted in successive decrease of the amplitude as compared with the first compressive load cvcle.

• 한국구조물진단유지관리공학회 논문집
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• 제1권1호
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• pp.65-73
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• 1997

In this paper, It is the effect of using fiber sheet (Carbon Fiber Sheet & Aramid Fiber Sheet) and Steel Plate for reinforced concrete beam. 25 specimens are tested, 16 specimens are for bending capacity and the other are for shear capacity. In the case of bending testing, the kind and quantity of the reinforcement materials, the bondage and the existence of crack were selected as experimental variables. In the case of shear testing, It is testified the effect of reinforcement with the variables of the method of reinforcement (side type and U type). As a result, Using the reinforcing materials can increase the capacity of bending and shear stress.

• 한국염색가공학회지
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• 제31권2호
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• pp.107-117
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• 2019

In case of pure rubber materials, the initial quality of the rubber materials would be excellent, however, the durability against external impact might be poor. In order to overcome the relatively low durability, textile cord could be employed with silicone rubber. We have studied the improvement of heat-resistant adhesion properties of silicone adhesives between silicone rubber and PET fibers by applying various conditions including dip solution recipe. The silicone rubber used was a platinum catalyst curing type and platinum catalyst type silicone adhesive was used as an adhesive to obtain an optimum adhesive force. Furthermore, the bonding mechanism between silicone and PET fiber was established.

• Journal of the Korean Wood Science and Technology
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• 제45권3호
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• pp.297-307
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• 2017

폐MDF 재생섬유를 인테리어 소품 제조용 원료로 이용하기 위해 MDF 제조용 리기다소나무 버진섬유와 MDF를 제조한 후 재해섬한 재생섬유에 대해 빨강, 노랑 및 파랑색 계열의 Bis-monochlorotriazine (MCT)계와 Vinyl sulfone(VS)계의 반응성염료, Anthraquinone계의 배트염료, Diazo계열의 직접염료 및 치자와 소목의 천연염료에 의한 염색 특성 및 일광견뢰도를 검토하였다. 염색 전의 버진섬유와 재생섬유의 색상은 각각 4.2YR과 4.4YR로 약간의 적색기가 있는 황색을 나타내고 있었으며, 재생섬유가 버진섬유에 비해 $L^*$의 값이 작아 약간 더 어두웠다. 적, 청, 황색계의 MCT계와 VS계의 반응성염료, 배트 염료, 직접염료 모두 버진섬유와 재생섬유에 관계없이 염색은 매우 양호하게 잘 이루어졌다. 재생섬유가 버진섬유보다 염착량은 약간 높았고, $L^*$와 V의 값은 약간 감소하였으나, 큰 차이는 없었다. 일광견뢰도는 염료에 따라 약간의 차이는 있으나 버진염색섬유가 재생염색섬유보다 더 큰 색차를 보이고 있어 불량하였다. 소목으로 염색한 재생섬유와 버진섬유의 색상은 각각 4.4YR과 4.0YR로 염색 전의 미염색 섬유와 거의 차이가 없었으나, 치자로 염색한 섬유의 색상은 각각 7.4YR과 6.9YR로 황색계의 반응성염료, 배트염료 및 직접염료보다 큰 색차를 보여 염색성은 우수하였으나 일광견뢰도는 불량하였다.

• Computers and Concrete
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• 제26권2호
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• pp.115-125
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• 2020

To reduce the damage of concrete in fire, a new type of lightweight cinder aggregate concrete was developed due to the excellent fire resistance of cinder. To further enhance its fire resistance, Polypropylene (PP) Fibers which can enhance the fire resistance of concrete were also used in this type of concrete. However, the bond behavior of this new type of concrete after fire exposure is still unknown. To investigate its bond behavior, 185 specimens were heated up to 22, 200, 400, 600 or 800℃ for 2 h duration respectively, which is followed by subsequent compressive and tensile tests at room temperature. The concrete-rebar bond strength of C30 PP fiber-reinforced cinder concrete was subsequently investigated through pull-out tests after fire exposure. The microstructures of the PP fiber-reinforced cinder concrete and the status of the PP fibre at different temperature were inspected using an advanced scanning electron microscopy, aiming to understand the mechanism of the bonding deterioration under high temperature. The effects of rebar diameter and bond length on the bond strength of PP fiber-reinforced cinder concrete were investigated based on the test results. The bond-slip relation of PP fiber-reinforced cinder concrete after exposure at different temperature was derived based on the test results.

• 조명전기설비학회논문지
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• 제27권12호
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• pp.10-15
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• 2013

In this paper, we propose a Lyot-type optical fiber comb filter based on a polarization-diversity loop structure (PDLS), which has flat-top pass bands and multiwavelength switching capability. Generally, the PDLS can remove the dependency of the filter on input polarization. The proposed filter is composed of a polarization beam splitter, two half-wave plates (HWPs), and two polarization-maintaining fiber loops concatenated with a $60^{\circ}$ offset between their principal axes. By controlling two HWPs, it can operate in a flat-top band mode or a lossy flat-top band mode with an inherent insertion loss of ~3.49dB. In particular, flat-top bands can be interleaved in both modes, which cannot be realized in a Lyot-Sagnac comb filter based on a fiber coupler. Compared with Solc-type high-order comb filters with the same order, the proposed filter shows sharper transition between pass and stop bands.

• 한국의류산업학회지
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• 제22권1호
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• pp.119-129
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• 2020

Unlike synthetic dyes, natural dyes do not affect the human body or create atmosphere pollution that are also mothproof, antibiotic and sterilized. This study examined the changes in dye adsorption properties according to mordant types and mordanting method to qualify trends using sage and rosemary extracts. Dyeability of sage extract is often similar to rosemary extract regardless of dyeing conditions. Dyeing properties of herb colorants on cotton, silk and wool fiber and effect of dyeing conditions on dye uptake were also compared. Dyed fabric showed a yellowish color and the dyeing affinity was somewhat good with rosemary extract. The surface color of the dyed fabrics was darkened by mordant treatment. The K/S value of herb colorants of protein fiber was higher than cellulose fiber. The concentration of mordant having the highest dyeing affinity was different from the mordant type. Regardless of the type of fiber, the K/S value of premordanting was the highest in mordanting method, and the K/S value of simultaneous mordanting indicated no noticeable mordant effect. The fastness of washing of silk fabric was reduced the most by mordant treatment. The lightfastness was reduced in Al mordant treatment regardless of the type of fiber. The lightfastness of wool increased somewhat by mordant treatment.

• 대한간호학회지
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• 제34권1호
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• pp.150-159
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• 2004

Purpose: The purpose of this study was to determine the effect of DHEA on hindlimb muscles(soleus, plantaris and gastrocnemius) in a focal brain ischemia model rat. Method: Twenty-seven male Sprague-Dawley rats were randomly divided into three groups: CINS(cerebral ischemia + normal saline), CIDH(cerebral ischemia + DHEA), or SHNS(sham + normal saline). Both the CINS and CIDH groups underwent a transient right middle cerebral artery occlusion operation. In the SHNS group, a sham operation was done. 0.34mmol/kg DHEA was administered daily by an intraperitoneal injection for 7days. Results: The muscle weight, muscle fiber cross-sectional area of the Type I muscle fiber of soleus and Type II muscle fiber of plantaris and gastrocnemius, myofibrillar protein content of gastrocnemius, and muscle strength in the CINS group decreased compared with the SHNS group. The muscle weight, muscle fiber cross-sectional area of the Type II muscle fiber of plantaris and gastrocnemius, myofibrillar protein content of soleus, and muscle strength in the CIDH group increased compared with the CINS group. Conclusion: It was identified that muscle atrophy could be induced during 7 days after a cerebral infarction, and DHEA administration during the early stages of a cerebral infarction might attenuate muscle atrophy.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.553-556
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• 2004

This paper is to investigate the spalling and fire endurance of high performance RC column member with PP fiber and lateral confinement of metal lath and non fire resistance removal type form. According to test results, combination of PP fiber and metal lath as well as use fire resistance non removal type form had favorable fire resistance by discharging internal vapour pressure and lateral confining. After fire endurance test, compressive strength decreased markedly caused by internal expansion pressure and crack. Residual strength of plain concrete was decreased to $22\%$. The use of PP fiber and lateral confinement of metal lath and non removal type form enhanced the residual strength above $40\%$. Especially, the combination of $0.1\%$ of PP fiber and lateral confinement with the level of 2.3T exhibited more than $51\%$ of residual strength. Therefore, to improve fire endurance and spalling resistance, the combination of $0.1\%$ of PP fiber and metal lath with 2.3T can be the proper measure.

• 대한토목학회논문집
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• 제28권3A호
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• pp.401-406
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• 2008

본 연구에서는 폐 PET병을 사용하여 구조적으로 효과가 있는 재생 PET섬유를 생산하였고 세 가지 형상의 재생 PET섬유와 시멘트 매트릭스와의 부착성능을 평가하였다. 또한 세 가지 형상의 재생 PET섬유로 보강된 콘크리트의 휨성능 시험을 실시하였다. 시험결과 재생 PET섬유는 우수한 부착성능의 증가를 보여주었다. 휨시험 결과 재생 PET섬유는 콘크리트의 휨인성을 증가시킨다는 것을 증명하였다. 부착 및 휨시험 결과를 기본으로 요철형 재생 PET섬유의 부착 및 휨성능이 다른 형상의 섬유와 비교하여 가장 우수하였다.