• 펄프종이기술
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• 제42권1호
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• pp.13-19
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• 2010

Four waste paper mills in Korea, where multifractors, devices for fiber fractionation, were installed, were selected to investigate how effectively and how differently the multifractors were used. They all used slot-type screens. Effective fiber fractionations by fiber length were expected by the multifractors, but in reality, they were used for selecting fiber furnishes that were flexible and hydrated. Flakes, which meant large fiber bundles, were rejected effectively by the multifractors. There existed a high regression coefficient between the fiber length differences and the freeness differences of the accepted and the rejected fiber furnishes.

• Computers and Concrete
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• 제17권5호
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• pp.597-612
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• 2016

The present work focuses on the use of coconut fiber in self compacting concrete. Self-Compacting Concrete (SCC) is a highly flowable, stable concrete which flows readily into place, filling formwork without any consolidation and without undergoing any significant segregation. Use of fibers in SCC bridge the cracks and enhance the performance of concrete by not allowing cracks to propagate. They contribute to an increased energy absorption compared to plain concrete. Coconut fiber has the highest toughness among all natural fibers. It is known that structures in the seismic prone areas are always under the influence of cyclic loading. To justify the importance of strengthening SCC beams with coir fiber, the present work has been undertaken. A comparison is made between cyclic and static loading of coconut fiber reinforced self compacting concrete (FRSCC) members. Using the test data obtained from the experiment, hysteresis loops were drawn and comparison of envelope curve, energy dissipation, stiffness degradation were made and important conclusions were draw to justify the use of coconut fiber in SCC.

• 한국농공학회논문집
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• 제47권2호
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• pp.63-72
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• 2005

In this study, the physical and mechanical properties of steel fiber reinforced lightweight polymer concrete were investigated experimentally with various steel fiber contents. All tests were performed at room temperature, and stress-strain curve and load-deflection curve were plotted up to failure. The unit weight of steel fiber reinforced lightweight polymer concrete was in the range of $1,020{\sim}1,160\;kg/m^3$, which was approximately $50\%$ of that of the ordinary polymer concrete, The compressive strength, splitting tensile strength, flexural toughness and flexural load-deflection curves after maximum load were shown with increase of steel fiber content. The stress-strain curves of steel fiber reinforced lightweight polymer concrete were bilinear in nature with a small transition zone, Based on these results, steel fiber reinforced lightweight polymer concrete can be widely applied to the polymer composite products.

• 정보저장시스템학회논문집
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• 제7권2호
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• pp.53-59
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• 2011

We have developed a compact and high-power mode-locked fiber laser for multilayered optical memory. Fiber lasers have the potential to be compact and stable light sources that can replace bulk solid-state lasers. To generate high-power pulses, we used stretched-pulse mode locking. The average power and pulse width of the output pulse from the fiber laser that we developed were 109 mW and 2.1 ps, respectively. The dispersion of the output pulse was compensated with an external single-mode fiber of 2.5 m length. The pulse was compressed from 2.1 ps to 93 fs by dispersion compensation. The fiber laser we have developed is possible to use as a light source of multilayered optical memory. We also present a fiber confocal microscope as an alignment-free readout system of multilayered optical memories. The fiber confocal microscope does not require fine pinhole position alignment because the fiber core is used as the point light source and the pinhole, and both of which are always located at the conjugated point. The configuration reduces the required accuracy of pinhole position alignment. With these techniques we can present an all-fiber recording and readout system for multilayered memories.

• International Journal of Concrete Structures and Materials
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• 제2권1호
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• pp.41-48
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• 2008

This study investigates the spalling properties of high strength concrete designed with various types of mineral admixture and diverse content ratios of polypropylene (PP) fiber. Experimental factors considered in series I are four pozzolan types of mineral admixture and series II consists of three shrinkage reducing types of mineral admixture. PP fiber was added 0.05, 0.10 and 0.15vol. % in each mixture of series I and series II, so that totally 27 specimens including control concretes in each series were prepared. Test results showed that the increase of fiber content decreased the slump flow of fresh concrete and increased or decreased the air content depending on the declining ratio of slump flow. For the properties of compressive strength, all specimens were indicated at around 50 MPa, which is high strength range; especially all specimens in series II were 60 MPa. Fire test was conducted in standard heating curve of ISO 834 with ${\phi}100{\times}200\;mm$ size of cylinder moulds for 1 hour. The specimens incorporating silica fume exhibited severe spalling and most specimens without the silica fume could be protected from the spalling occurrence in only 0.05vol % of PP fiber content. This fire test results demonstrated that the spalling occurrence in high strength concrete was not only affected by concrete strength related to the porosity of microstructure but also, even more influenced by micro pore structure induced by the mineral admixtures.

• 패션비즈니스
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• 제22권2호
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• pp.107-117
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• 2018

Nettle fiber, a sustainable fiber, was applied to the fabrication of denim to identify changes in textile appearance and formation. For the weaving of nettle denim, nine specimens, distinguished by three kinds of composite use of nettle fiber and three stages of fabrication processes, were used. The kinetic characteristics of the nine specimens were measured by the KES-FB system, and the images of the specimens of finished denim textiles, captured with a CCD Camera, were analyzed. In terms of the extensibility (EM) of nettle denim, all specimens showed post-processing increase, thereby suggesting an easy transformation of the textile as a source material for denim fabric. The effects of washing on the woven formation of denim were also identified. The geometric roughness (SMD), the problematic property of bast-fiber-like nettle fiber, was found to be decreased by washing. In terms of the bending rigidity (B) of the textile, the post-processing shrinking percentage of elastic nettle denim was found to decrease; all specimens that underwent bio-washing only also manifested that post-processing elasticity increased. To improve the draping of nettle denim, a mixed spinning together with washing were found to be advantageous. In terms of the shear stiffness (G), which is closely associated with the appearance of clothes, the formation of textile was improved regardless of the types of processing, including bio-washing and bleach washing.

• 대한전자공학회논문지SD
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• 제37권10호
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• pp.51-56
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• 2000

본 논문에서는 용융-인장형 광섬유커플러 내부에 격자를 새겨 넣음으로써 광섬유커플러형 add/drop 필터를 구현해 보았다. 결합비가 99.8%인 광섬유커플러와 길이가 10mm인 광섬유격자로 구성된 add/drop 필터의 투과스펙트럼상의 최대 반사효율과 drop 효율은 각각 99%와 83%를 보여주었다.

• 복식문화연구
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• 제19권4호
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• pp.863-875
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• 2011

The purpose of this study was to survey the clothing behavior, care and the fiber preferences of multi-cultural families living in Korea. The data was collected using questionnaire surveys based on pre-tests, and a main survey conducted in Seoul, Gyeonggi Province and Chungcheong Province. The 258 participants came from 151 multi-cultural families and 107 Korean families. The results of this study were as follows: First, Filipinos owned more clothes than the Chinese and bought clothes more frequently. The Filipinos spent 10,000~30,000 Korean won on all types of clothing. Each time, the Chinese spent more money when purchasing jackets. Second, when health was the greatest concern for underclothes, they chose cotton fiber as their preferred fiber. When beauty was of greatest concern for blouses they chose cotton. When beauty was of greatest concern for skirts and jackets they chose natural fibers such as silk, wool or linen. Filipinos preferred synthetic fibers because they are easy to care for, and the Chinese preferred natural fibers due to their beauty, especially for pants. Third, multi-cultural families laundered at home using only a washing machine. All fibers were laundered together into the washer without any sorting. This study can contribute to providing basic data for an understanding of the clothing behavior and laundry styles of multi-cultural families which may be useful data in the apparel market in Korea given the relative and direct changes relevant to various clothing cultures.

• 한국광학회지
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• 제13권5호
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• pp.377-383
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• 2002

개회로 구성의 FOG용 All-Digital Closed Loop(ADCL) 신호처리기는 종래의 아날로그 방식의 위상추적 신호처리를 디지털로 구현한 것으로 안정화기를 채용하지 않고 이를 FOG에 적용하였을 때 0.26$\mu$rad/$^{\circ}C$의 온도의존성을 가지기 때문에 중급 이상의 FOG(fiber optics gyroscope)용 신호처리기로서는 문제가 있다. 온도드리프트는 위상변조를 위해 사용되는 위상변조기의 변조진폭과 위상지연의 온도드리프트에 의해 발생하는 것으로 FOG의 출력에서 위상변조신호의 고조파 성분의 비를 일정하게 함으로 써 광섬유 위상변조기의 동작을 안정화하여 FOG의 드리프트를 측정 불가한 수준으로 줄일 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제31권5호
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• pp.35-42
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• 2003

본 연구는 전보(정 등, 2002)에서 제조된 직물유리섬유 강화집성재의 박리 및 수분 흡착특성을 조사해 보기 위해서 실시되었다. 침지 박리시험에서, 3가지 형태의 소재 모두 박리를 나타내지 않았지만, control재를 제외한 모든 형태의 소재는 삶음 박리에서 박리가 발생하였다. 수분흡착시험은 40℃, 상대습도 90% 조건에서 48시간동안 실시하였다. 횡단면 흡습성은 모든 소재에서 다르지 않았다. 유리섬유로 된 소재에서 방사단면과 접선단면은 control재와 비교하여 수분 흡착이 지연되었다. 수분흡착 이방성에서, 유리섬유 함입된 소재는 적은 수분흡착을 나타내었다.