• Title/Summary/Keyword: 전단율

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Performance Evaluation of Organic-Inorganic Adhesives and Organic Adhesives for Polishing Tile Adhesion (폴리싱 타일 접착용 유·무기계 접착제와 유기계 접착제의 성능 평가)

  • Seo, Jong-Oh;Jeon, Jin-Ho;Park, Chang-Hwan;Cho, Sung-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.211-212
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    • 2023
  • Polishing tiles among porcelain tiles are more durable and aesthetic than ceramic tiles, so their demand has recently increased. In particular, since polishing tiles have a very low absorption rate, organic adhesives with chemical bonds are mainly used. However, organic adhesives have low economic efficiency and some volatile organic compounds (TVOCs). Therefore purpose of this study was to evaluate the performance of polishing tile adhesion by developing organic-inorganic adhesives, which have chemical bonds and mechanical bonds. As a result, since the amorphous chain and chemical bonds of the polymer in the tile adhesives, both tensile and shear adhesion strength were satisfied with the KS L 1592, KS L 1593, and the rate of length change itself in the thermal cycling was lower than organic adhesives. So it is thought that it is possible to replace some organic adhesives.

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A Study on Flexural Strength of Prominent Section of SC Beams (요철단면 SC보의 휨 내력에 관한 연구)

  • Ryu, Soo-Hyun;Ahn, Hyung-Joon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.197-204
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    • 2006
  • This experimental study of prominent section bending behavior beam without shear connector provides bond capacity between concrete profile and initial stiffness of SC beam by comparing the test result with a theological analysis result and an ANSYS(common structural analysis program) analysis result. The compared result provides a fundamental study for practical use of efficient SC beam. Test result indicates 88%-98% rate of theological result in moment capacity and composition ratio shows 30%-70%. In other words, the results are insufficient to make a complete composite action. Therefore, it is need to make pull shear connection of connection method.

Soil Characteristics according to the Geological Condition of Soil Slopes in Landslide Area (산사태지역 토층사면의 지질조건별 토질특성)

  • Kim, Kyeong-Su
    • The Journal of Engineering Geology
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    • v.16 no.4 s.50
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    • pp.359-371
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    • 2006
  • In this study, the soil characteristics are analyzed using the result of various soil tests as an object of the soil layer of natural slopes in landslides areas composed with gneiss, granite, and the tertiary sedimentary rock. To investigate the soil characteristics according to landslide and non landslide areas, soils are sampled from Jangheung, Sangju and Pohang. The landslides at three areas are occurred due to heavy rainfall in same time. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. On the basis of the landslide data and the result of soil test, the soil characteristics at the landslide area and the differentiation between landslide area and non landslide area are analyzed. However soil characteristics have a little differentiation to geological condition, the uniformity coefficient and the coefficient of gradation of soils at the landslide area is larger than those of soils at the non landslide area. Also, the proportion of fine particle of soils at the landslide area is higher. The plastic limit of soils sampled from the granite and the sedimentary rock regions is larger than that sampled from the gneiss region. However the liquid limit is irrelevant to the geological condition. Also, the consistency of soils at the landslide area is smaller. The natural moisture content of soils in the sedimentary rock regions is larger than that of the granite and gneiss. It is mainly influenced by mineral composition, soil layer structure, weathering condition, and so on. The soils sampled from landslide area have higher porosity and lower density than those from non landslide area. It means that the soils of landslide area have poor particle size distribution and loose density. Therefore, the terrain slope with poor distribution and loose density is vulnerable to occur in landslides. Also, landslides are occurred in the terrain slope with high permeability. The permeability is mainly influenced by the soil characteristics such as particle size distribution, porosity, particle structure, and the geological origins such as weathering, sedimentary environment. Meanwhile, the shear strength of soils is little difference according to the geological condition. But, the internal friction angle of soils sampled from the landslide area is lower than that of soils from the non landslide area. Therefore, the terrain slope with low internal friction angle is more vulnerable to the landslide.

Quality Characteristics of Press Ham Containing Conjugated Linoleic Acid-Triglyceride (Conjugated linoleic acid-triglyceride가 함유된 프레스햄 품질특성)

  • Lee, Jeong-Ill;Joo, Y.K.;Kang, G.H.;Yang, H.S.;Jeong, J.Y.;Joo, S.T.;Park, G.B.
    • Journal of Animal Science and Technology
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    • v.49 no.1
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    • pp.109-120
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    • 2007
  • CLA was chemically synthesized by alkaline isomerization method using corn oil. CLA-TG was synthesized by chemical reaction using sodium methoxide. For the control, 10% of back fat among the total component was only added without the annex of CLA-TG. For the first treatment, 5% of CLA-TG among the lard component added into the press ham was replaced. For the 2nd, 3rd and 4rd treatments, 10%, 15% and 20% of CLA-TG was respectively replaced. Manufacture press ham using CLA-TG were vacuum packaged and then stored during 1, 7, 14, 21 and 28 days at 4℃. Samples were analyzed for shear force value, sensory evaluation, TBARS, fatty acid composition and CLA content. Shear force value of control was significantly higher than that of CLA-TG treatment groups(P<0.05). All treatments were increased by the passage of storage time. No remarkable differences were found in sensory properties among control and CLA-TG treatment groups. CLA-TG treatment groups showed significantly(P<0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. In the change of fatty acid composition, the contents of C14:0~C20:4 were decreased significantly by CLA-TG additive. Whereas the increase level of CLA-TG additive resulted in the significantly higher unsaturated fatty acid and CLA content. Summing up the a forementioned results, press ham manufacturing with CLA-TG additive was not affected in sensory evaluation. Also, it may be assumed that the high quality press ham can be manufactured with the extent of storage period and CLA accumulation.

Effect of Dietary Glycine Betaine on Pork Qualities During Storage (Glycine betaine의 급여가 돈육의 품질에 미치는 영향)

  • Park, G.B.;Hur, S.J.;Yang, H.S.;Lee, J.I.;Kwck, S.J.;Lee, J.D.;Huh, N.E.;Kim, J.S.;Joo, S.T.
    • Journal of Animal Science and Technology
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    • v.46 no.5
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    • pp.821-832
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    • 2004
  • A total of 80 pigs were used to investigate the effect of dietary glycine betaine(N,N,N-trimethylglycine) on pork quality during cold storage. About 70 kg pigs were randomly a1loted into one of four experimental diet groups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg live weight, and pH, color(CIE $L^* a^* b^*$), shear force, sarcomere length, lipid oxidation and composition of fatty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine in pork loin was significantly increased(P<0.05) with increasing of glycine betaine level in diet. Pork loins from dietary betaine groups showed significantly higher muscle pH and lower CIE $b^*$ values compared to control group after 13 days of storage. There were significant differences in shear force values among pork loins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarcomere length than those of dietary betaine groups. Dietary glycine betaine increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were decreased with increasing dietary betaine level. However, dietary glycine betaine did not affect lipid oxidation (TSARS) and sensory evaluation during cold storage.

Evaluation of Shear Bond Strength and Adhesive Bond Durability of Mixed Species Structural Glued Laminated Timber (이수종 구조용집성재의 전단접착력 및 접착내구성 평가)

  • Shim, Sangro;Yeo, Hwanmyeong;Shim, Kugbo
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.1 s.129
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    • pp.87-96
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    • 2005
  • This study was carried out to evaluate the shear bond strength and adhesive bond durability of structural glued laminated timber (glulam) manufactured with mixed species lumber of Korean red pine, Korean pine and Japanese larch, using resorcinol adhesive and water-based polymeric-isocyanate adhesive (WPI). Each board used as a glulam lamina was graded by visual inspection. The visual lumber grade of the all species was very low due to the large size and number of knots and the steep slope of grain. In view of the results, appropriate pruning, sawing and drying processes might be needed to produce high grade lamina lumber with small knot size and drying defect free. Shear bond strength of every tested glulam specimen ranged between 7.9 and $9.9N/mm^2$, and much higher than the Korean Standard (KS) for glulam shear bond strength, $7.1N/mm^2$. There was not much shear bond strength difference between wood/resorcinol and wood/WPI. The resorcinol adhesive bond durability exceeded KS requirements. However, delamination on the end-grain surfaces of WPI glulam submerged in both room temperature and boiling water severely occurred, and its durability did not meet KS requirements. Further investigations may be required, and special care should be taken, to ensure long service life of WPI glulam used for exterior application. Results of this study are expected to be useful for improvement of mechanical properties and structural performance of mixed species glulam.

Comparison on Performance, Carcass Yield and Meat Quality Characteristics of Korean Indigenous Commercial Chicken (토종닭 실용계의 생산성, 도체율 및 육질특성 비교)

  • Kim, Ki-Gon;Cha, Jae-Beom;Kim, Hee-Jin;Choo, Hyo-Jun;Park, Byoungho;Hong, Eui-Chul
    • Korean Journal of Poultry Science
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    • v.48 no.4
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    • pp.277-285
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    • 2021
  • This study was conducted to compare performance, carcass yield, and meat quality of 4 Korean indigenous commercial chickens (Hanhyup 3: G, Sorae 1: V, Woorimatdak 1: S, Woorimatdak 2: W). A total of 384 chickens were divided into 4 treatments with 4 Korean indigenous commercial chickens, 6 repetitions per treatment, and 16 birds per treatment (♀ 8 birds, ♂ 8 birds). For 12 weeks, body weight was significantly higher in G and V breeds than S and W breeds (P<0.01), but body weight gain lower in S breed (P<0.05). Feed conversion ratio was significantly higher in W breed at 8~10 wk of age (P<0.05). There was no significant difference on livability among four treatments. Carcass yield and fresh meat ratio were highest in V breed at 12 wk of age (P<0.05). On breast meat, shear force was lower in G breed (P<0.05), and higher in male than in female (P<0.05). Lightness (L*) of breast meat was higher in female except V breed, and redness (a*) was significantly higher in breed G (P<0.05). Yellowness (b*) of breast meat was higher in G and V breeds, and higher in male than in female except breed G. In conclusion, G and V breeds showed superior performance, and S and W breeds showed superior meat quality.

Green Energy Technology Commercialization Promotion Methods using Smart Green Certification System and Regional Cooperation Network Construction (스마트 녹색인증 시스템 및 지역별 협력네트워크 구축을 통한 그린에너지 기술사업화 활성화 방안)

  • Ryu, Se-Hee
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.140-140
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    • 2010
  • 최근 정부가 저탄소 녹색성장을 새로운 국정비전으로 제시하고 혁신적 그린에너지 기술개발을 위해 연평균 20%이상의 R&D 예산을 증액하고 있는 상황에서 연구개발결과의 상용화율 제고를 위한 연구기획, 평가, 관리시스템의 개선이 시급한 실정이다. 특히 선진국의 경우 최근 3년간 에너지분야 R&D의 상용화율이 미국 35.9%, 유럽 46.8%로서 24.2%인 한국에 비해 매우 높다고 할 수 있다. 이와같은 격차가 존재하는 것에 대해서 다양한 요인을 생각해볼 수 있겠지만, 크게 시장적인 또는 산업적인 측면에서의 중요도를 기준으로 연구과제를 선정하지 못하고 있다는 점과 연구개발결과를 효율적으로 사업화하고 있지 못하고 있다는 점을 생각해볼 수 있다. 특히 에너지 분야는 대규모 자금의 초기소요 및 개발기술 상용화기간의 장기화등으로 인해 사업화 실적이 타산업대비 매우 저조한 편이다. 이와같은 연구결과의 사업화와 관련된 문제점을 극복하기 위한 노력으로 국내에서 다양한 형태의 기술사업화 지원프로그램이 운영괴고 있으나, 에너지 분야에 특화된 프로그램은 부족한 상황이다. 반면에 미국의 경우, 재생에너지 R&D분야 전문투자자 그룹인 클린테크그룹 등을 중심으로 2002년부터 현재까지 다수의 녹색기술분야에 특화된 기술사업화 지원 프로그램을 운영하고 있다. 그 결과 현재까지 약 9년간 총 16억$의 투자유치에 성공함으로써 민간투자 활성화 역할을 담당하고 있다. 따라서 국내의 경우에도 이와같은 에너지 R&D 결과를 효과적으로 사업화로 연계시킬 수 있는 관련 프로그램 등이 시급히 도입되어야 할 것이다. 본 논문에서는 국내의 사업화 부진문제를 해결하기 위한 하나의 방안으로서 올해부터 정부주관으로 시행되고 있는 녹색인증사업을 활용하여 사업화가 유망한 기술 및 기업을 선별하고, 이에 대해 사업화 지원을 위한 후속프로그램을 적극 지원함으로써 연구개발결과의 경제적 활용도를 획기적으로 개선하는 방안을 제시하고자 한다. 또한 사업화 지원프로그램의 효율성을 높이기 위해 수도권, 영남권, 호남권 등 지역별 TP 등을 중심으로 기술사업화 협력 네트워크를 구축하고, 이를 기반으로 한 수요기술조사, 기술마케팅, 투자자유치 등의 관련프로그램을 개발하여 전단의 시스템과 융합시킴으로써 향후의 정부주도 R&D결과의 상용화율을 제고할 수 있는 시스템을 제안하고자 한다. 이에는 에너지 R&D분야별 기술적 시장적 특징분석, 지역별 산업특성과 기술공급 서플라이 체인분석을 토대로 한 기술이전 잠재수요기업 투자자를 대상으로 한 맞춤형 기술사업화 프로그램 등이 포함된다. 마지막으로 제안된 시스템에 대한 타당성 검증을 위해 올해년도에 시행한 녹색인증 기술사업화 연계프로그램 및 기술사업화 협력네트워크 활용사례 등을 분석하고, 향후 발전방향으로서 기술사업화 유관기관간간 기술사업화 정보교환 및 사업화 유망기술 기업 마케팅 등을 기본내용으로 한 시장지향적 녹색에너지 R&D 관리 시스템 구축방안을 제시하고자 한다.

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Analysis of Soil Characteristics and its Relationship According to the Geological Condition in Natural Slopes of the Landslide Area (산사태지역 자연사면의 지질별 토질특성 및 상관관계 분석)

  • Kim, Kyeong-Su
    • The Journal of Engineering Geology
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    • v.17 no.2 s.52
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    • pp.205-215
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    • 2007
  • In this study, the soil characteristics are analyzed using the result of various soil tests as an object of the soil layer of natural slopes in landslides areas. Also, the relationship with landslides and interrelation with each soil properties are analyzed. The landslides in three areas with different geological condition are occurred due to heavy rainfall in same time. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. However soil characteristics have a little differentiation to geological condition, the soils sampled from landslide area have higher proportion of fine particle and porosity, and lower density than those from non landslide area. In case of same geological condition, landslides are occurred in the terrain slope with high permeability. The permeability is mainly influenced by the soil characteristics such as particle size distribution, porosity, particle structure, and the geological origins such as weathering, sedimentary environment. The soil layer with high internal friction angle is more stable than that with low internal friction angle in all geological condition. The permeability is mainly influenced by effective particle size, coefficient of uniformity, coefficient of gradation, porosity, density and so on. Also, those have interrelation with each factor. These interrelations are similar in all study area. Meanwhile, in proportion as the void ratio and the porosity rises the permeability increases.

Adhesive Performance and Fracture Toughness Evaluation of FRP-Reinforced Laminated Plate (FRP 보강적층판의 접착성능 및 파괴인성평가)

  • Jung, Hong-Ju;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.6
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    • pp.868-875
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    • 2015
  • In order to replace existing slit type steel plate on the wooden structure joint, the FRP-reinforced laminated plates were produced. Four types of FRP-reinforced laminated plates were produced according to the type of reinforcement and adhesive, and before applying to the joint, the adhesion performance test according to KSF 3021 and KSF 2160 and the Compact Tension (CT) type fracture toughness test specified in ASTM D5045-99 were carried out. As a result of adhesion performance test, all GFRP textile, GFRP sheet, and GFRP Textile-Sheet type FRP-reinforced laminated plates satisfied the requirement of soaking delamination percentage with smaller than 5% based on KS standard. However, aramid type specimen satisfied the standard as the soaking delamination percentage of 4.8% but it did not satisfied the standard as the water proof soaking delamination percentage of 70%. As a result of fracture toughness test, the volume ratio of reinforcement to timber became 23% so that the strength of FRP-reinforced laminated plates increased by two to four times in comparison to the control specimen. It was confirmed that the GFRP Textile-Sheet type specimen was most resistant to the fracture most since the ratio of stress intensity factor compared with that of the control increased to 61% owing to the parallel arrangement of glass fiber to the load. As a result of tensile shear strength test using FRP-reinforced laminated plates and nonmetal dowels, it is about 12% lower than metal connectors.