• Title/Summary/Keyword: RC test

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Quality Control of Ginseng Products(Part I) - The saponins isolated from ginseng roots and leaves - (인삼제품(人蔘製品)의 품질개량(品質改良)에 관(關)한 연구(硏究) (제일보(第一報)) - 인삼근(人蔘根) 및 엽(葉) Saponin의 비교연구(比較硏究) -)

  • Cho, Han-Ok;Cho, Sung-Hwan;Kim, Soo-Ja
    • Applied Biological Chemistry
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    • v.22 no.1
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    • pp.10-17
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    • 1979
  • The saponins isolated form the herb of Panax ginseng C.A. Meyer were investigated as compared with ginseng root saponins. By adopting DEAE cellulose ion exchange chromatography the pure saponins were isolated from Korean ginseng roots and leaves. The ginseng root and leaf saponins showed some differences in the pattern of the two-dimensional thin layer chromatogram. The ratio of panaxadiol to panaxatriol in the saponins was 1.7 in the roots and 3.5 in the leaves. Infra-red spectrum of ginseng leaf saponins isolated by liquid chromatography was identical with that of root saponins.

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A Review of Clinical Shoulder Assessment Scales (견관절의 임상적 평가도구에 관한 고찰)

  • Yang, Dong-Hoon;Kim, Kun-Hyung;Kim, Haeng-Beom;Choi, Yang-Sik;Park, Young-Bae
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.123-135
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    • 2007
  • Objectives : A number of instruments have been developed to measure the quality of life in patients with various shoulder disorders. Much progress has been made in this area, and currently an appropriate instrument exists for each shoulder state. The purpose of this study is to review the instruments that are currently in use for assessing the shoulder joint. Methods : A literature research was performed to choose appropriate scales for assessment of function and the disability of the shoulder. Theoretically based scales were selected for review. Therefore, 11 scales were reviewed. The status of scales involved in shoulder treatment of acupuncture throughout several countries was evaluated. Results : 11 scales: The American shoulder and elbow surgeons evaluation form(ASES), Constant Shoulder Score, The disabilities of the arm, shoulder and hand(DASH), Shoulder Disability Questionnaire (SDQ), The Shoulder Pain And Disability index(SPADI), The simple shoulder test(SST), Oxford Shoulder Questionnaire(OSQ), The Rotator Cuff quality-of-life Measure(RC-QoL), Western Ontario Shoulder Instability Index(WOSI), Western Ontario Osteoarthritis of the Shoulder Index(WOOS), Western Ontario Rotator Cuff Index(WORC), wereevaluated. Each measurement has its own composition and characteristics. Their validity, reliability, responsiveness and practical characteristics were already evaluated. We found 3 domestic and 10 overseas papers about shoulder treatments using acupuncture assessed with shoulder scales. Conclusions : In clinical research, the selection of the measurement scale should take account of the condition of disease, the patient's traits and the characteristics of the research. Moreover, appropriate scales, which havevalidity, reliability, responsiveness and practical characteristics, are needed to enhance the quality of research.

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Tactility and Mechanical Properties of Marketing Towel (타월용 시판소재의 촉감과 역학적 특성)

  • Jung, Ha-Kyung;Kim, Sun-Kyung;Cho, Hyo-Sook;Kim, Joo-Yong
    • Journal of the Korean Home Economics Association
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    • v.44 no.10
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    • pp.57-66
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    • 2006
  • The purpose of this study was to evaluate the relationship between the tactile sensation and mechanical properties of towel. Six kinds of towels with different surface structure and fiber composition were used for this study. To evaluate the tactility of towel, 36 adjectives were collected and then 11 adjectives were selected. The subjective evaluation was examined by one to one comparative method and by blind test for estimating the only the sense of touch of the towels. Kawabata's Evaluation system for fabrics was used to measure the mechanical properties which are tensile, bending, shear, compression, surface, weight, and thickness of six towels. The results are as follows; First, surface structure of the towels had an effect on estimation the sense of touch. Pile surface was evaluated thicker, compacter, more cushiony, and more elastic. Waffle surface was evaluated knottier and rougher, and microfiber suede surface was evaluated softer and denser. Second, the highest value of the mechanical properties measured were G, 2HG, B, and SMD of 100% cotton 100% pile, WC, T, and W of elban loop pile, WT, 2HB, and LC of 100% cotton cut pile, RT and MIU of microfiber suede, and RC of microfiber waffle. Third, the 11 adjectives were correlated with more than one mechanical property. 'Knotty' and 'rough' were correlated with MMD and SMD, 'soft' were correlated with B, 2HB, MMD, and SMD. 'Thick', 'heavy', 'compact', and 'elastic' were correlated with WC, T, and W, 'cushiony' was correlated with WC. 'Stiff' was correlated with B and 2HB, 'dry out' was correlated with RT, WC, MIU, and T. 'Dense' was correlated with RT and SMD.

Nonlinear analysis of damaged RC beams strengthened with glass fiber reinforced polymer plate under symmetric loads

  • Abderezak, Rabahi;Daouadji, Tahar Hassaine;Rabia, Benferhat;Belkacem, Adim
    • Earthquakes and Structures
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    • v.15 no.2
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    • pp.113-122
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    • 2018
  • This study presents a new beam-column model comprising material nonlinearity and joint flexibility to predict the nonlinear response of reinforced concrete structures. The nonlinear behavior of connections has an outstanding role on the nonlinear response of reinforced concrete structures. In presented research, the joint flexibility is considered applying a rotational spring at each end of the member. To derive the moment-rotation behavior of beam-column connections, the relative rotations produced by the relative slip of flexural reinforcement in the joint and the flexural cracking of the beam end are taken into consideration. Furthermore, the considered spread plasticity model, unlike the previous models that have been developed based on the linear moment distribution subjected to lateral loads includes both lateral and gravity load effects, simultaneously. To confirm the accuracy of the proposed methodology, a simply-supported test beam and three reinforced concrete frames are considered. Pushover and nonlinear dynamic analysis of three numerical examples are performed. In these examples the nonlinear behavior of connections and the material nonlinearity using the proposed methodology and also linear flexibility model with different number of elements for each member and fiber based distributed plasticity model with different number of integration points are simulated. Comparing the results of the proposed methodology with those of the aforementioned models describes that suggested model that only uses one element for each member can appropriately estimate the nonlinear behavior of reinforced concrete structures.

Model Updating of a RC Frame Building using Response Surface Method and Multiobjective Optimization (반응표면법 및 다목적 최적화를 이용한 철근콘크리트 건물모델의 모델 개선)

  • Lee, Sang-Hyun;Yu, Eunjong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.1
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    • pp.39-46
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    • 2017
  • In this paper, a model updating procedure based on the response surface method combined with the multi-objective optimization was proposed and applied for updating of the FE models representing a low-rise reinforced concrete building before and after the seismic retrofit. The dynamic properties to be matched were obtained from vibration tests using a small shaker system. By varying the structural parameters according to the central composite design, analysis results from the initial FE model using a commercial software were collected and used to produce two regression functions each of which representing the errors in the natural frequencies and mode shapes. The two functions were used as the objective functions for multi-objective optimization. Final solution was determined by examining the Pareto solutions with one iteration. The parameters representing the stiffnesses of existing concrete, masonry, connection stiffness in expansion joint, new concrete, retrofitted members with steel section jacketing were selected and identified.

1.5 kV GaN Schottky Barrier Diode for Next-Generation Power Switches (차세대 전력 스위치용 1.5 kV급 GaN 쇼트키 장벽 다이오드)

  • Ha, Min-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.11
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    • pp.1646-1649
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    • 2012
  • The $O_2$ annealing technique has considerably suppressed the leakage current of GaN power devices, but this forms NiO at Ni-based Schottky contact with increasing on-resistance. The purpose of the present study was to fabricate 1.5 kV GaN Schottky barrier diodes by improving $O_2$-annealing process and GaN buffer. The proposed $O_2$ annealing performed after alloying ohmic contacts in order to avoid NiO construction. The ohmic contact resistance ($R_C$) was degraded from 0.43 to $3.42{\Omega}-mm$ after $O_2$ annealing at $800^{\circ}C$. We can decrease RC by lowering temperature of $O_2$ annealing. The isolation resistance of test structure which indicated the surface and buffer leakage current was significantly increased from $2.43{\times}10^7$ to $1.32{\times}10^{13}{\Omega}$ due to $O_2$ annealing. The improvement of isolation resistance can be caused by formation of group-III oxides on the surface. The leakage current of GaN Schottky barrier diode was also suppressed from $2.38{\times}10^{-5}$ to $1.68{\times}10^{-7}$ A/mm at -100 V by $O_2$ annealing. The GaN Schottky barrier diodes achieved the high breakdown voltage of 700, 1400, and 1530 V at the anode-cathode distance of 5, 10, and $20{\mu}m$, respectively. The optimized $O_2$ annealing and $4{\mu}m$-thick C-doped GaN buffer obtained the high breakdown voltage at short drift length. The proposed $O_2$ annealing is suitable for next-generation GaN power switches due to the simple process and the low the leakage current.

Structural performance of ribbed ferrocement plates reinforced with composite materials

  • Shaheen, Yousry B.I.;Mahmoud, Ashraf M.;Refat, Hala M.
    • Structural Engineering and Mechanics
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    • v.60 no.4
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    • pp.567-594
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    • 2016
  • The main objective of the current research is estimating the flexural behavior of ferrocement Ribbed Plates reinforced with composite material. Experimental investigation was carried out on fifteen plates; their dimensions were kept constant at 1200 mm in length, 600 mm width and 100 mm thick but with different volume fraction of steel reinforcement and number of ribs. Test specimens were tested until failure under three line loadings with simply supported conditions over a span of 1100 mm. Cracking patterns, tensile and compressive strains, deformation characteristics, ductility ratio, and energy absorption properties were observed and measured at all stages of loadings. Experimental results were compared to analytical models using ANSYS 10 program. Parametric study is presented to look at the variables that can mainly affect the mechanical behaviors of the model such as the change of plate length. The results showed that the ultimate strength, ductility ratio and energy absorption properties of the proposed ribbed plates are affected by the volume fraction and the type of reinforcement, and also proved the effectiveness of expanded metal mesh and woven steel mesh in reinforcing the ribbed ferrocement plates. In addition, the developed ribbed ferrocement plates have high strength, ductility ratio and energy absorption properties and are lighter in weight compared to the conventional RC ribbed plates, which could be useful for developed and developing countries alike. The Finite Element (FE) simulations gave good results comparing with the experimental results.

Repair of seismically damaged RC bridge bent with ductile steel bracing

  • Bazaez, Ramiro;Dusicka, Peter
    • Steel and Composite Structures
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    • v.26 no.6
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    • pp.745-757
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    • 2018
  • The inclusion of a ductile steel bracing as means of repairing an earthquake-damaged bridge bent is evaluated and experimentally assessed for the purposes of restoring the damaged bent's strength and stiffness and further improving the energy dissipation capacity. The study is focused on substandard reinforced concrete multi-column bridge bents constructed in the 1950 to mid-1970 in the United States. These types of bents have numerous deficiencies making them susceptible to seismic damage. Large-scale experiments were used on a two-column reinforced concrete bent to impose considerable damage of the bent through increasing amplitude cyclic deformations. The damaged bent was then repaired by installing a ductile fuse steel brace in the form of a buckling-restrained brace in a diagonal configuration between the columns and using post-tensioned rods to strengthen the cap beam. The brace was secured to the bent using steel gusset plate brackets and post-installed adhesive anchors. The repaired bent was then subjected to increasing amplitude cyclic deformations to reassess the bent performance. A subassemblage test of a nominally identical steel brace was also conducted in an effort to quantify and isolate the ductile fuse behavior. The experimental data from these large-scale experiments were analyzed in terms of the hysteretic response, observed damage, internal member loads, as well as the overall stiffness and energy dissipation characteristics. The results of this study demonstrated the effectiveness of utilizing ductile steel bracing for restoring the bent and preventing further damage to the columns and cap beams while also improving the stiffness and energy dissipation characteristics.

Antioxidant and Genotoxic Inhibition Activity of Ethanol Extract from the Inonotus obliquus (차가버섯 분획물의 항산화활성 및 유전독성 억제효과)

  • 함승시;오상화;김영균;신광순;장현유;정국훈
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.7
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    • pp.1071-1075
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    • 2003
  • This study was performed to observe the antioxidative and genotoxic effect of the fractions from Inonotus obliquus using DPPH test and micronucleus assay. Stepwise fractionation of the ethanol extract from Inonotus obliquus was done by using hexane, chloroform, ethyl acetate, butanol and water to obtain effective fraction. Each fraction was tested in 1.5 ${\times}$ 10$^{-4}$ DPPH. Among six fractions, the ethyl acetate fraction showed the highest electron donating activities (46.5 $\mu\textrm{g}$/mL). The results on genotoxic effects on insoluble fractions and most of fractions showed cytotoxic effects more than 90% activity. These results suggest that some components contained in the Inonotus obliquus showed such activities and much more studies have to perform.

Experimental and Analytical studies on Failure Behavior of Stud Shear Connectors in CFT Structures (CFT 구조에 적용된 스터드 전단연결재의 파괴 거동에 대한 실험 및 해석적 연구)

  • Lee, Sangyoon
    • Journal of the Society of Disaster Information
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    • v.9 no.4
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    • pp.400-412
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    • 2013
  • For the composite behavior of steel tube and inner concrete, the shear connectors should be applied to the CFT structures. However, the present design codes don't provide the design criteria that can be applied on shear connectors in the CFT structures typically filled with plain concrete. This study has been carried out to propose design criteria (shear strength and resistance factor) for the stud shear connectors in CFT structures. Experimental tests using the push-out specimens with the plain concrete blocks and finite element analysis were conducted for the purpose of verifying the main failure mode to propose the shear strength of studs in CFT structures. From the results of this study, the main failure mode of studs in CFT structures is splitting crack of concrete and this failure mode reduces shear strength of studs in CFT structures relatively to those embedded in RC blocks.