• Title/Summary/Keyword: Structural property

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Studies on the Myofibrillar Proteins Part I. Phase Microscopy of Myofibrils from Rabbit Muscle (근원섬유 단백질에 관한 연구 (제1보) 근원섬유에 관한 형태학적 연구)

  • Yang, Ryung;Kim, Chul-Jai;Moon, Yoon-Hee;Yu, Ju-Hyun
    • Korean Journal of Food Science and Technology
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    • v.6 no.2
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    • pp.79-85
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    • 1974
  • To obtain further information concerning the nature myofibrillar proteins in a food system, an investigation has been conducted to compare the change in the biochemical property of the myofibril with the changes in the morphological structure of the myofibril. When myofibrils were prepared with 0.16 M KCl-0.04 M Tris-HCl, the band pattern was clear and distinct. There was a uniform thickening of A-band, a sharp appearence of Z-lines and a wide I-band. The band pattern of myofibrils was changed as the composition of extraction solution was changed. Also the ATPase activity of myofibril changed as the length of sarcomere changed. When myofibrils were treated with a low concentration of trypsin, myofibrils turned in the contracted state. With the progress of prolonged trypsin treatment, most of myofibrils exhibited a pattern of alternating light and dark bands, supercontracted pattern. Although myofibrils exhibited a supercontracted band pattern, the ATPase activity of myofibril continued to increase with the progress of trypsin treatment. An assumption was made that tropomyosin may be located in Z-line and that troponin-tropomyosin complex can inhibit the ATPase activity of myofibrils through the structural alternation of myofibril.

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Comparison of Some Physicochemical Properties and Adsorption of Organic Cations between Ca- and Na-bentonites (Ca-형 및 Na-형 벤토나이트의 제반 물성 및 유기양이온 흡착비교)

  • 고상모;김자영
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.4
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    • pp.243-257
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    • 2002
  • Ca-type and Na-type bentonites show the great difference of some physicochemical properties. Na exchanged bentonite is mainly used for the foundry and construction materials in domestic utilization. This study tries to identify in detail the differences of some physicochemical properties and thermal properties between Ca-type and Na-type bentonites. Also the adsorption behavior and interlayer expansion for the HDTMA (Hexadecyltrimethylammonium) exchanged and CP (Cetylprydinium) exchanged Ca-type and Na-type bentonites were compared. Na-type bentonite shows the strong alkaline property, high viscosity and swelling compared to Ca-type bentonite. However, two types are very similar for the cation exchange capacity and MB (Methylene Blue) adsorption. The decomposition of adsorbed and interlayer water of Na-type bentonite is caused in the lower temperature than Ca-type bentonite. And Ca-type bentonite shows the decomposition of structural water in the lower temperature than Na-type bentonite. The interlayer expansion of montmorillonite resulted to the intercalation of HDTMA and CP into bentonite is so strongly caused from 12~15 $\AA$ to $40\AA$ (basal spacing). HDTMA-bentonite is almost expanded to $37~38\AA$ when 200% CEC equivalent amount of HDTMA is added, and CP-bentonite is fullly expanded to 40 $\AA$ in the 140% CEC equivalent amount of CP It means that CP causes the stronger interlayer expansion of montmorillonite and easier adsorption than HDTMA. Adsorption behaviors of CP into bentonite is so stable and continuously sorbed in the proportion to the treatment of amount until 200% of the CEC equivalents. CP-bentonite shows the same adsorption behavior regardless of Ca-type or Na-type montmorillonite.

Feasibility of Ultrasonic Inspection for Nuclear Grade Graphite (원자력급 흑연의 산화 정도에 따른 초음파특성 변화 및 초음파탐상의 타당성 연구)

  • Park, Jae-Seok;Yoon, Byung-Sik;Jang, Chang-Heui;Lee, Jong-Po
    • Journal of the Korean Society for Nondestructive Testing
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    • v.28 no.5
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    • pp.436-442
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    • 2008
  • Graphite material has been recognized as a very competitive candidate for reflector, moderator, and structural material for very high temperature reactor (VHTR). Since VHTR is operated up to $900-950^{\circ}C$, small amount of impurity may accelerate the oxidation and degradation of carbon graphite, which results in increased porosity and lowered fracture toughness. In this study, ultrasonic wave propagation properties were investigated for both as-received and degradated material, and the feasibility of ultrasonic testing (UT) was estimated based on the result of ultrasonic property measurements. The ultrasonic properties of carbon graphite were half, more than 5 times, and 1/3 for velocity, attenuation, and signal-to-noise (S/N) ratio respectively. Degradation reduces the ultrasonic velocity slightly by 100 m/s, however the attenuation is about 2 times of as-receive state. The results of probability of detection (POD) estimation based on S/N ratio for side-drilled-hole (SDHs) of which depths were less than 100 mm were merely affected by oxidation and degradation. This result suggests that UT would be reliable method for nondestructive testing of carbon graphite material of which thickness is not over 100 mm. In accordance with the result produced by commercial automated ultrasonic testing (AUT) system, human error of ultrasonic testing is barely expected for the material of which thickness is not over 80 mm.

A Study on the Characteristics of Organic Concept and Interpretation at F. L. Wright and T. Ito's Architecture - Focus on Wright's Robie House and Ito's Sendai Mediatheque - (라이트와 이토 건축의 유기적 개념과 해석 특성에 관한 연구 - 라이트의 로비 하우스와 이토의 센다이 미디어 테크를 중심으로 -)

  • Park, Hyung-Jin
    • Korean Institute of Interior Design Journal
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    • v.22 no.4
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    • pp.23-32
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    • 2013
  • This study represents something in common and differences of organic characteristics between early modern architecture and contemporary architecture analysing F. L. Wright's Robie House and Toyo Ito's Sendai Mediatheque. A natural organic body cannot be separated from the natural environment, and each part of an architecture has each own property and forms a whole at the same time. That is a basic concept of organic architecture, and a framework for analysis is set up based on it. The followings are similarities and differences of organic concept and interpretation between Wright's Robie House and Ito's Sendai Mediatheque First, Wright' Robie house unites with the natural surrounding, using a physically close connection to the ground. In contract, Ito's Mediatheque shows characteristics of noncentural and fluidic space that are metaphorically reflecting tangible and intangible of factors in modern city, where there is an ambiguous physical boundary between architecture and urban environment. Next, floors, walls and ceilings of Wright's housing as for basic building blocks are physically separated and at the same time form formative unity from the point of view of a physical and structural organic body. And continuous flow of faces of separated walls form an organism united with the nature from a physical aspect. On the contrary to this, there is an no-boudary and floating organic architecture of integrated structure from ambiguous setting of relation between architecture and urban space in Ito's architecture. Especially, Mediatheque shows semantic integration of floating urban environmental factors through horizontal and vertical integration of horizontal slabs, vertical pipes, and skins. Last, horizontal and vertical factors of Wright' Housing is appreciated as an basic experienced structure in terms of spacial perception and fluidic inner spaces in Wright's housing is completed with a series of spatial experiences in a visual sense. On the other hand, no-boundary and floating space of Ito's architecture accept user's physical and virtual body. Especially, there is an integration transcending beyond time and space, accepting an imaginary body and events with the course of time at Ito's Mediatheque.

Seismic Fragility Evaluation of Cabinet Panel by Nonlinear Time History Analysis (비선형시간이력해석을 이용한 수배전반의 지진취약도 도출)

  • Moon, Jong-Yoon;Kwon, Min-ho;Kim, Jin-Sup;Lim, Jeong-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.50-55
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    • 2018
  • Earthquakes are almost impossible to predict and take place in a short time. In addition, there is little time to take aggressive action when an earthquake occurs. Therefore, there are more casualties and property damage than with other natural disasters. Recently, earthquakes have been occurring all over the world. As the number of earthquakes increase, studies on the safety of structures are being carried out. On the other hand, there are few studies on the electric facilities, which are relatively non - structural factors. Currently, electrical equipment in Korea is often not designed for earthquake safety and is quite vulnerable to damage when an earthquake occurs. Therefore, in this study, modeling was conducted through ABAQUS similar to an actual cabinet panel and 3D dynamic nonlinear analysis was performed using a natural seismic. According to seismic zone I and normal ground rock conditions of the power transmission and transmission facility seismic design practical guide, the maximum response acceleration of the performance level was 0.157g. In this study, however, it was not safe to reach the limit state of 30% of the analytical result at 0.1g for the general cabinet panel. From the results, the seismic fragility curve was derived and analyzed. The derived seismic fragility curve is presented as a quantitative basis for determining the limit state of the cabinet panel and can be utilized as basic data in related research.

Fabrication and Physical Properties of ZrO2(m)-Al2O3ZrO2(t)-Al2O3 Structural Ceramics (ZrO2(m)-Al2O3ZrO2(t)-Al2O3 세라믹스의 제조와 물리적 특성)

  • Park, Jae-Sung;Park, Ju-Tae;Park, Jung-Rang
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.4
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    • pp.140-148
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    • 2010
  • The effects of the addition of either monoclinic $ZrO_2(ZrO_2(m))$ or tetragonal $ZrO_2(ZrO_2(t))$ containing 5.35[wt%] $Y_2O_3$ on the physical properties and electrical conductivity of $Al_2O_3$ were investigated. The addition of $ZrO_2$(m) and $ZrO_2$(t) increased sintered density of $Al_2O_3$. The Vickers hardness also increased as addition of $ZrO_2$(t) increased going through a maximum at 20[wt%] and the hardness of the specimens was found to be dependent on the sintered density. The addition of $ZrO_2$(t) improved the hardness of $Al_2O_3-ZrO_2$ systems and the $ZrO_2$(m) addition showed the better effect on the thermal shock property of $Al_2O_3-ZrO_2$ systems than that of the $ZrO_2$(t) addition. Above 15[wt%] addition of $ZrO_2$(t), the electrical conductivity is gradually increased with increasing applied voltage but not effects by addition of $ZrO_2$(m).

Numerical Analysis of Crash Impact Test for External Auxiliary Fuel Tank of Rotorcraft (회전익항공기용 외부 보조연료탱크 충돌충격시험 수치해석)

  • Kim, Hyun-Gi;Kim, Sungchan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.724-729
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    • 2017
  • The crashworthiness of the fuel tank of a rotorcraft is verified through the crash impact test. The crash impact test has a high risk of failure due to the application of an excessive load, which can seriously affect the overall development schedule of the aircraft. Therefore, a lot of effort has been made to minimize the possibility of failure in the actual test by carrying out a numerical analysis of the crash impact test of the fuel tank in the initial design stage. Recently, an external auxiliary fuel tank was added to increase the cruising distance. In this study, the numerical analysis results of the crash impact test based on several different shapes of the external auxiliary fuel tank are presented, in order to evaluate its crashworthiness. For the numerical analysis, smoothed particle hydrodynamics (SPH), which is one of the fluid-structure coupled analysis methods, is applied and the test conditions prescribed by US military standards are reflected in the analysis conditions. In addition, the material property data previously obtained by the specimen test of the actual fuel tank is applied to the numerical analysis. As a result, the equivalent stress of the fuel tank material itself and the metal fitting is provided and the possibility of acquiring data for designing the crash-worthiness of the external auxiliary fuel tank is evaluated by examining the behavior and working load of the internal mounted components.

Development of the Novel Cosmetics Impregnation Material and Study on Makeup W/O Emulsions using It (새로운 화장료 함침재의 개발과 이를 활용한 메이크업 유중수형 에멀전에 관한 연구)

  • Kang, Sungsoo;Kim, Hyeon Jeong;Oh, Se Woong;Park, Sang Wook;Kim, Kyung Seob
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.1
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    • pp.27-33
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    • 2017
  • Up to now, better convenience and portability were important factors in the development of the cosmetics and achieved by immersing low viscosity makeup water-in-oil (W/O) emulsion into the impregnation material. Conventionally, polyurethane sponges having porous network structures and hard textures have been dominantly used. It has an advantage of easy to manufacture because of its good impregnation property due to its structural characteristics. However, it releases emulsion too much at first use, and shows unexpected dramatic decline during the period of usage. In this study, we studied on makeup W/O emulsion with various features and developed the new foaming sponge, which showed excellent formability and proper absorption and discharge ability of cosmetic composition through the combination of natural rubber (NR) and styrene butadiene rubber (SBR). This impregnation material is characterized by the softness of elasticity like a rubber, high elongation and uniform output. We confirmed that this material can be used to develop makeup products using various oils depending on polarity and controlling the viscosity of the makeup W/O emulsion. Thus, it is concluded that these results provide valuable information in developing new cosmetics impregnation materials.

Study on the Site Classification and Site Coefficients for the Seismic Design Regulations of KBC (KBC 내진설계기준을 위한 지반분류와 지반계수에 대한 연구)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.1 s.53
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    • pp.59-65
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    • 2007
  • Site classification of IBC and KBC is based on the ft-kips unit system and is not friendly for the linear interpolation of the site coefficients due to the implicit relationship between a site class and site coefficients, defining a site class by the range of the soil properties, not by a single soil property. Also, the site class definition of KBC has too wide range of soil properties for each soil class. making the structural engineers difficult to estimate the site coefficients for the diverse soil layers. In this study, a new site classification in SI unit system was proposed for the seismic design codes of KBC etc., and the comparison of the site coefficients of $F_{a}\;and\;F_{v}$ was also performed to investigate the possibility of the linear interpolation of the site coefficients with the proposed new site classification. According to the study results, it was more reasonable for the linear interpolation of the site coefficients to utilize the proposed new site classification considered the Sl unit system and the soil characteristics of the 30m soil layer beneath the shallow embedded foundation, and the linear interpolation of the acceleration coefficients for the design spectrum can be performed more reasonably defining the site coefficients for the representative shear wave velocities of each site class. With the study results, a new site classification, and the linear interpolation permitted acceleration coefficients fer the design spectrum were proposed for the modification of the seismic design regulations of KBC.

The Thermal Conduction Property of Structural Concrete using Insulation Performance Improvement Materials (단열성능향상 재료를 사용한 구조용 콘크리트의 열전도 특성)

  • Park, Young-Shin;Kang, Min-Gi;Kim, Jung-Ho;Ji, Suk-Won;Jeon, Hyun-Kyu
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.1
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    • pp.9-15
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    • 2016
  • The part of a building with the biggest energy loss is the exterior and many studies are actively conducted to reduce the energy loss on that part. However, most studies consider the window frames and insulation materials, but many studies do not discuss the concrete that takes more than 70% of the exterior. In order to minimize the energy loss of buildings, it is necessary to enhance the concrete's insulation performance and studies need to be conducted on this. Therefore, this study used a micro foam cell admixture, calcined diatomite powder, and lightweight aggregates as a part of a study to develop a type of concrete with improved insulation performance that has twice higher thermal conductivity compared to concrete. It particularly secured the porosity inside concrete to lower thermal conductivity. As a result of the experiment, the slump and air capacity showed fair results, but all mixtures containing micro foaming agent showed 14.3~35.1% lower mass per unit of volume compared to regular concrete. Compressive strength decreased slightly due to the materials used to improve the insulating performance, but it all satisfied this study's target strength(24MPa). Thermal conductivity was up to twice higher than that of regular concrete.