• 한국건축시공학회지
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• 제11권5호
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• pp.419-425
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• 2011

콘크리트의 특성상 상대적으로 작은 인장강도로 인하여 균열에 취약한 성질을 가지고 있다. 따라서 본 연구에서는 무근 콘크리트의 균열저감을 위하여 천연섬유 중 성능이 우수한 것으로 알려진 황마섬유에 대하여 다른 종류의 셀룰로오스 섬유와 비교 검토하여 보았다. 그 결과 황마 섬유의 경우 유동성 측면에서 다른 섬유에 비하여 양호한 결과를 나타내었고, 특히 소성수축 균열 저항성의 경우 혼입량 0.9 및 1.2 kg/$m^3$에서 플레인 대비 50 % 이상의 균열저감 성능을 발휘하였으며, 충격시험의 경우 WF 및 PULP 섬유에서 최종파괴까지 5회의 낙하횟수가 걸리는 반면 황마섬유는 혼입량에 따라 차이가 있지만 10~18회로 우수한 인성적 성질을 발휘하고 있는 것으로 나타났다.

• 한국생산제조학회지
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• 제19권1호
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• pp.140-144
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• 2010

In recent years there has been a growing interest for the use of natural fibers in composite applications due to their low cost, environmental friendliness, and good mechanical properties. The purpose of this study is to determine the characteristic of bending strength on bamboo fiber reinforced polymer composites. The parameters of RTM process depend on the weight ratio of bamboo fiber and resin, the number of bamboo ply and amount of hardening agent. Besides the existence of pore in composites according to vacuum time investigated a effect on mechanical properties of reinforced polymer composites. Test result shows that compressive strength was a maximum(approximately 1,840kgf/$cm^2$) value when weight ratio of resin was 12%.

• 한국염색가공학회지
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• 제13권5호
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• pp.306-311
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• 2001

Natural colorants haute attracted much attention all over the world because of their non-hazardous nature. The world is becoming increasingly aware of environmental Issues, such as ozone layer depletion, water pollution and waste disposal problems. The use of synthetic dyestuffs for their synthesis and application in the dyeing industries has been criticized due to introduction of contaminants into the environment. This has led to the desire to turn to the traditional, and more natural way of life. In this study, the colorants of extract of Ginkgo biloba bark were analysed and their dyeing properties on silk, wool and cotton were studied. It was found that uv-visible absorption spectra of extract of Ginkgo biloba bark showed two strong absorption Peaks in the range of 240 ∼400 In. From the result of IR spectra, the major ingredient of extract of Gikgo biloba bark seems to be the flavon which is one of the flavonoid derivatives. Silk, wool, and cotton dyed with the extract of Ginkgo biloba bark showed a reddish yellow color. Their color differences were increased drastically with repetition of dyeing by three times.

• 패션비즈니스
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• 제12권4호
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• pp.131-142
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• 2008

One of the major fashion trends is the naturalism and ecology-conscious trend. The natural looks required in the trend require somewhat random distribution of yarn linear density, which results in irregular appearance along the yarn. This is a technically challenging work of producing yarns that look natural far from being artificial yet maintaining the intricately aesthetic randomness without causing process disturbances. This study focused on the characteristics of fabrics made of natural cellulosic fibers including hemp, ramie, flax, and polyester fabrics. Image analysis of the fabric samples included area measurement of yarn specimen, FFT and inverse FFT. Measurements of bending resistance, thickness, air permeability, and weight were also implemented to interpret the structural differences.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.88-91
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• 2004

In this study, a number of natural fiber henequen reinforced polymer matrix composites were successfully fabricated by means of a compression molding technique using chopped henequen fibers surface-treated with different electron beam irradiation (EBI) dosages, thermoplastic poly(butylene succinate), thermosetting unsaturated polyester and phenolic resins. Their interfacial and thermal characteristics were studied in terms of interfacial shear strength, fracture surface, dynamic mechanical properties, dimensional stability, and thermal stability using single fiber microbonding test, SEM, DMA, TMA, and TGA. The results show that their interfacial and thermal properties significantly depend on the intensity of EBl treatment on the natural fiber surface.

• 대한기계학회논문집A
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• 제30권8호
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• pp.916-922
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• 2006

In recent years there has been a growing interest for the use of natural fibers in composite applications due to their low cost, environmental friendliness, and good mechanical properties. The purpose of this study is to determine the characteristic of bending strength on bamboo fiber reinforced polymer composites. The parameters of RTM process depend on the weight ratio of bamboo fiber and resin, the number of bamboo ply and amount of hardening agent. Mechanical properties was investigated for each process factor of polymer composites. Test result shows that bending strength was a maximum(approximately 85MPa) value when composite thickness was 6mm and weight ratio of resin was 13%.

• Structural Engineering and Mechanics
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• 제55권1호
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• pp.79-92
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• 2015

In this study, free vibration analyses of symmetric laminated cantilever and simply supported damaged composite beams are investigated by using finite element method (FEM). Free vibration responses of damaged beams are examined using Euler Bernoulli beam and classical lamination theories. A computer code is developed by using MATLAB software to determine the natural frequencies of a damaged beam. The local damage zone is assumed to be on the surface lamina of the beam by broken fibers after impact. The damaged zone is modeled as a unidirectional discontinuous lamina with $0^{\circ}$ orientations in this study. Fiber volume fraction ($v_f$), fiber aspect ratio ($L_f/d_f$), damage length ($L_D$) and its location (${\lambda}/L$), fiber orientation and stacking sequence parameters effects on natural frequencies are investigated. These parameters are affected the natural frequency values significantly.

• 한국농공학회논문집
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• 제57권2호
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• pp.67-73
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• 2015

This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

• 접착 및 계면
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• 제9권4호
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• pp.24-29
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• 2008

두 종류의 천연섬유, 즉 면섬유와 목분을 이용하여 폴리프로필렌 - 천연섬유 복합재료를 제조하고 혼합가공시 유변학적 특성과 열적특성을 고찰하였다. PP/천연섬유 복합재료에서 천연섬유의 함량이 증가함에 따라 토오크 값이 상승하였고, 면섬유의 경우 낮은 체적 밀도로 인해 목분 복합재료보다 높은 토오크값을 나타내었다. PP의 MI에 따라서는 낮은 MI의 PP/천연섬유 복합재료에서 더 높은 토오크값이 관찰되었다. X-선 회절분석과 시차주사열분석을 통해 천연섬유의 함량이 증가될수록 PP/천연섬유 복합재료의 결정화온도는 상승하나 결정화도는 감소함이 확인되었다.

• Journal of Ginseng Research
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• 제44권1호
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• pp.115-122
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• 2020

Background: In aged skin, degradation of collagen fibers, which occupy the majority of the extracellular matrix in the dermis, and changes of aquaporin 3 (AQP3) and skin constituents, such as hyaluronic acid and ceramide, cause wrinkles and decrease skin moisturization to contribute to dryness and lower elasticity skin. Red ginseng (RG) is used as a cosmetic and food material and is known to protect from UVB-induced cell death, increase skin hydration, prevent wrinkles, and have an antioxidative effect. But, in general, RG used as a material is the soluble liquid portion in the solvent, and the part that is not soluble in the solvent is discarded. Thus, we made the whole RG into microgranulation and dispersed in water to produce gel form for using entire RG, and it was named red ginseng NaturalGEL (RG NGEL). Methods: RG NGEL was investigated for matrix metalloproteinases inhibitory activity, induction of Type I collagen, AQP3, hyaluronan synthetase 2, serine palmitoyl transferase, ceramide synthase 3, and filaggrin expression and compared with RG water extract. Results: RG NGEL reduced the levels of UV-induced matrix metalloproteinases and increased Type I collagen in human fibroblast cells and upregulated AQP3, hyaluronan synthetase 2, serine palmitoyl transferase, ceramide synthase 3, and filaggrin expressions in human keratinocytes compared with RG water extract. Conclusion: RG NGEL has the potential as an effective reagent for antiaging cosmetics to improve wrinkle formation and skin hydration.