• Title/Summary/Keyword: 원형단면사

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Comparison of hand, thermal and optical properties of woven fabrics made of triangular and circular shaped filaments (삼각사와 원형사로 제직된 직물의 태, 열적성질 및 광학적 성질의 비교)

  • 심현주;홍경아
    • Science of Emotion and Sensibility
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    • v.5 no.3
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    • pp.47-52
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    • 2002
  • The handle of fabrics including tactility and sense of visuality are closely related to the factors governing the preferences of end-users. This study shows the change of mechanical properties, thermal properties and optical properties by comparing two fabrics which are woven with circular shaped filaments and with triangular ones. The fabric mechanical characteristics required for primary hand values were evaluated with the KES-FB system. The mechanical properties measured by KES-FB system shows that fabrics made of circular filaments are greater than those made of triangular ones. The thermal properties measured by KES-F7(Thermo Labo II) system shows that the values of the initial maximum value(qmax) and the thermal conductivity(λ) are higher in the fabric made of triangular shaped ones. When the light rays tall on a surface, the fabric made of triangular filaments shows more lustrous than circular ones.

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A new species of Fimbristylis (Cyperaceae): F. jindoensis J. Kim & M. Kim (하늘지기속(사초과)의 신종: 진도하늘지기 (Fimbristylis jindoensis J. Kim & M. Kim))

  • Kim, Jonghwan;Kim, Muyeol
    • Korean Journal of Plant Taxonomy
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    • v.45 no.4
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    • pp.318-322
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    • 2015
  • A new species, Fimbristylis jindoensis J. Kim & M. Kim, is herein named and described. It is found on wet lowland mountain slopes in Jindo-gun, Jeollanam-do, Korea. Fimbristylis jindoensis shares several characteristics (long-creeping rhizomes, oblong spikelets, brown scales, and three-sided achenes) with the related species F. pierotii Miq. It is, however, distinct from F. pierotii, which has terete culms with five to six furrows that are 9-48 cm tall, flowers in June to July, a dry grassland habitat, fewer than ten spikelets, and simple anthela inflorescences. In contrast, the new species has shallow furrowed oval culms which are 57-93 cm tall, flowers in July to August, a wet mountain habitat, more than twenty spikelets, and compound anthela inflorescences.

An Analysis of Simplified Cable Stayed Bridge with FRP Components (FRP 부재를 이용한 단순 사장교 모델의 거동 해석)

  • Park, Jae-Gyun;An, Il-Chan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.5
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    • pp.543-550
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    • 2007
  • As an emerging materials in construction fields, FRP(fiber reinforced polymer) has been used in many area of civil engineering for its light weight and high strength. In this study we chose the 2nd Jindo-Bridge as a prototype, and evaluate effect of replacing steel components to FRP components through simplified 3D linear analysis. Static and modal analysis are done and the analysis results are compared with steel case analysis. From the static analysis results, the maximum stress of each component and maximum displacement of middle span are compared. Due to the reduction of deadload, the FRP structure causes less deflection than the original steel structure and from the reduced section (cable) analysis we confirmed the previous result. The occurrence wind velocity of flutter is compared by the frequency ratio.

Ultrastructure of the Fertilized Egg Envelope from Dark Sleeper, Eleotrididae, Teleost (경골어류 구굴무치과 얼룩동사리의 수정란 난막 미세구조)

  • Kim, Dong-Heui;Reu, Dong-Suck;Deung, Young-Kun
    • Applied Microscopy
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    • v.32 no.1
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    • pp.39-44
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    • 2002
  • The ultrastructure of the fertilized egg envelope from dark sleeper, Odontobutis obscurus interrupta belong to Eleotrididae was studied using scanning and transmission electron microscopes. The fertilized egg of dark sleeper was of transparent, ellipsoidal, adhesive and demersal type, and there were numerous oil droplets in the yolk sac and adhesive filaments in the area of the animal pole. The outer surface of egg envelope was smooth with pore canal. The fertilized egg envelope consisted of two layers, an outer nonadhesive layer and an inner layer, consisting of seven horizontal low electron-dense lamellae alternating with the middle electron dense interlamellae. These ultrastructural characters of fertilized egg envelope from dark sleeper can be utilized in taxonomy of teleost.

Structural Behavior of the Buried flexible Conduits in Coastal Roads Under the Live Load (활하중이 작용하는 해안도로 하부 연성지중구조물의 거동 분석)

  • Cho, Sung-Min;Chang, Yong-Chai
    • Journal of Navigation and Port Research
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    • v.26 no.3
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    • pp.323-328
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    • 2002
  • Soil-steel structures have been used for the underpass, or drainage systems in the road embankment. This type of structures sustain external load using the correlations with the steel wall and engineered backfill materials. Buried flexible conduits made of corrugated steel plates for the coastal road was tested under vehicle loading to investigate the effects of live load. Testing conduits was a circular structure with a diameter of 6.25m. Live-load tests were conducted on two sections, one of which an attempt was made to reinforce the soil cover with the two layers of geo-gird. Hoop fiber strains of corrugated plate, normal earth pressures exerted outside the structure, and deformations of structure were instrumented during the tests. This paper describes the measured static and dynamic load responses of structure. Wall thrust by vehicle loads increased mainly at the crown and shoulder part of the conduit. However additional bending moment by vehicle loads was neglectable. The effectiveness of geogrid-reinforced soil cover on reducing hoop thrust is also discussed based on the measurements in two sections of the structure. The maximum thrusts at the section with geogrid-reinforced soil cover was 85-92% of those with un-reinforced soil cover in the static load tests of the circular structure; this confirms the beneficial effect of soil cover reinforcement on reducing the hoop thrust. However, it was revealed that the two layers of geogrid had no effect on reducing the overburden pressure at the crown level of structure. The obtained values of DLA decrease approximately in proportion to the increase in soil cover from 0.9m to 1.5m. These values are about 1.2-1.4 times higher than those specified in CHBDC.

Deformation Characteristics of Underground Pipe with In-situ Soil CLSM (현장발생토 CLSM을 이용한 지하매설관의 변형특성)

  • 박재헌;이관호;조재윤;김석남
    • Journal of the Korean Geotechnical Society
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    • v.20 no.3
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    • pp.129-139
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    • 2004
  • During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the small-scaled model test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM.. From the model test in the lab, it was found out that the use of CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the gound surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was smaller than those in the other cases, and the absolute value was almost zero. Judging from the small-scaled model test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing failure of the underground pipes.

Evaluation of Construction Operation and Design Properties of CLSM for Corrugated Pipe in Underground (파형강관을 이용한 지하매설물용 뒤채움재 설계 및 시공성 평가)

  • Lee Kwan-Ho;Park Jae-Heon
    • International Journal of Highway Engineering
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    • v.8 no.2 s.28
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    • pp.63-74
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    • 2006
  • During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

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