• Title/Summary/Keyword: Pulled-out

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Fracture Behaviors of SiCf/SiC Composites Prepared by Hybrid Processes of CVI and PIP (화학침착법과 고분자함침 열분해법의 복합공정으로 제조한 SiCf/SiC 복합체의 제조 공정에 따른 파괴거동)

  • Park, Ji Yeon;Han, Jangwon;Kim, Daejong;Kim, Weon-Ju;Lee, Sea Hoon
    • Journal of the Korean Ceramic Society
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    • v.51 no.5
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    • pp.430-434
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    • 2014
  • $SiC_f$/SiC composites were prepared using the hybrid process of chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP). Before the application of PIP, partially matrix-filled preform composites with different densities were fabricated by control of chemical vapor infiltration time and temperature. The changes of the final density of the $SiC_f$/SiC composites had a tendency similar to that of preform composites partially filled by CVI. Composites with lower density after the CVI process had a larger increment of density during the PIP process. Three types of microstructures were observed on the fractured surface of the composite: 1) well pulled-out fibers and lower density, 2) slightly pulled-out fibers and higher density, and 3) only bulk SiC. The different fractions and distributions of the microstructures could have an effect on the mechanical properties of the composites. In this study, $SiC_f$/SiC composites prepared using a hybrid process of CVI and PIP had density values in the range of $1.05{\sim}1.44g/cm^3$, tensile strength values in the range of 76.4 ~ 130.7 MPa, and fracture toughness values in the range of $11.2{\sim}13.5MPa{\cdot}m^{1/2}$.

Baby Giraffe Rope-Pulled Out of Mother Suffering from Dystocia without Proper Restraint Device (기린 난산에서 물리적 보정장치 부재시 밧줄을 이용한 태아 견인)

  • Yong, Hwan-Yul;Park, Suk-Hyun;Choi, Myoung-Keun;Jung, So-Young;Ku, Dae-Chang;Yoo, Jong-Tae;Yoo, Mi-Jin;Yoo, Mi-Hyun;Eo, Kyung-Yeon;Yeo, Yong-Gu;Kang, Shin-Keun;Kim, Heon-Youl
    • Journal of Veterinary Clinics
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    • v.26 no.1
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    • pp.113-116
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    • 2009
  • A 4-year-old female reticulated giraffe (Giraffa camelopardalis reticulata), at Seoul Zoo, Gwacheon, Korea had a male calf with no help of proper restraint devices. The mother giraffe was in a danger of dystocia more than 7 hours in labor after showing the calf's toe of the foreleg which protruded from her vulva. After tugging with a snare of rope on the metacarpal bone of the calf and pulling it, the other toe emerged. Finally, with two snares around each of metacarpal bones, the calf was completely pulled out by zoo staff. After parturition, the dam was in normal condition for taking care of the calf and her progesterone hormone had also dropped down to a normal pre-pregnancy.

Arthroscopic Double-pulley Suture-bridge Technique for Rotator Cuff Repair

  • Kim, Kyung-Cheon;Rhee, Kwang-Jin;Shin, Hyun-Dae;Byun, Ki-Yong;Yang, Jae-Hoon;Kim, Dong-Kyu;Yeon, Kyu-Woong
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2009.03a
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    • pp.162-162
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    • 2009
  • After preparation of the bone bed, two doubly loaded suture anchors with suture eyelets are inserted at the articular margin of the greater tuberosity. A retrograde suture-passing instrument penetrates the rotator cuff to retrieve the sutures through the modiWed Neviaser or subclavian portal. An ipsilateral pair of suture eyelets in the suture anchor is passed through the margins of the rotator cuff tear. The blue suture of the second and third pair is pulled out of the lateral cannula, and the threaded blue suture of the third pair in the needle is passed through the blue suture of the second pair. After retrieving the blue suture of the firrst pair through the anterior portal, it is pulled out to pass the blue suture of the third pair through the eyelet of the anteromedial anchor. The blue suture is linked between two anchors. The medial row of suture bridge is repaired with a sliding knot, and the sutures are not cut. Once the rotator cuff repair using the suture-bridge technique has been performed, the two blue strands in the anterior portal are tied. We describe our technique that possesses the advantages of both the double-pulley and suturebridge techniques, which improves the pressurized contact area and maximizes compression along the medial row.

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Data driven inverse stochastic models for fiber reinforced concrete

  • Kozar, Ivica;Bede, Natalija;Bogdanic, Anton;Mrakovcic, Silvija
    • Coupled systems mechanics
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    • v.10 no.6
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    • pp.509-520
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    • 2021
  • Fiber-reinforced concrete (FRC) is a composite material where small fibers made from steel or polypropylene or similar material are embedded into concrete matrix. In a material model each constituent should be adequately described, especially the interface between the matrix and fibers that is determined with the 'bond-slip' law. 'Bond-slip' law describes relation between the force in a fiber and its displacement. Bond-slip relation is usually obtained from tension laboratory experiments where a fiber is pulled out from a matrix (concrete) block. However, theoretically bond-slip relation could be determined from bending experiments since in bending the fibers in FRC get pulled-out from the concrete matrix. We have performed specially designed laboratory experiments of three-point beam bending with an intention of using experimental data for determination of material parameters. In addition, we have formulated simple layered model for description of the behavior of beams in the three-point bending test. It is not possible to use this 'forward' beam model for extraction of material parameters so an inverse model has been devised. This model is a basis for formulation of an inverse model that could be used for parameter extraction from laboratory tests. The key assumption in the developed inverse solution procedure is that some values in the formulation are known and comprised in the experimental data. The procedure includes measured data and its derivative, the formulation is nonlinear and solution is obtained from an iterative procedure. The proposed method is numerically validated in the example at the end of the paper and it is demonstrated that material parameters could be successfully recovered from measured data.

Estimation of Pull-out force by using modified Direct Shear Apparatus (개설된 직접전단시험기(CNS)를 이용한 보강재의 인발력 추정)

  • 유병선;이학무;장기태;한희수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.145-154
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    • 2003
  • When a nail pulled out in dense, granular soil, the soil in the vicinity of the nail tends to dilate, but its dilatancy results in a normal stress concentration at the soil/nail interface, thereby increasing the pull-out resistance of the inclusion. It is thought to be occurring within the resistance zone where the soil mass is at stationary state and the reinforcement are held in position by the soil, due to the friction or bond. In this paper, A series of direct shear and interface tests were conducted by using so called‘Constant Normal Stiffness Test Apparatus’which was modified and improved from the conventional direct shear box test rig. Unlikely the normal shear box test, this enables to simulate the different constraint effects of surrounding soil during shear under the conditions of constant stress and volume, constant normal stiffness. The aim of the research programme is to get better understanding of pull-out bond mechanism, thus to explore the possibility of evaluating the pull-out bond capacity of soil/reinforcement at the preliminary design stage from the laboratory test.

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The Study on the Types of Hair Cut Designs based on the Face Measurements of Male College Student (남자대학생의 얼굴계측에 따른 유형별 헤어컷 디자인 연구)

  • Kim, Mi-Jung;Lee, Sang-Rye
    • Fashion & Textile Research Journal
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    • v.6 no.6
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    • pp.740-748
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    • 2004
  • The purpose of this research is to observe the face types of types of haircut design that is the basis for the completion of a hair styling mainly with case of male college student. For the purpose of this, I carried out direct and indirect observation and measurement for faces of 293 male college student who attended universities in Busan, and measured face types which were classified by the group analysis preferred hair style in order to do actual hair cut design. The result of this research is as follow. This paper conducted the element analysis in regard to the direct and indirect items of face, and it pulled out 5 elements. As a result of group analysis with elements as independent variables, they are classified into4 types. For actual hair cut design, 4 types classified by group analysis and nearing models analyzed. This research bring accurate information classified face types.

Friction Coefficient and Microstructure of Reaction-Bonded Silicon Carbide According to Sliding Conditons (반응소결 탄화규소의 접동조건에 따른 마찰계수 및 미세구조)

  • 김호균;김인섭;이병하
    • Journal of the Korean Ceramic Society
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    • v.32 no.7
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    • pp.825-831
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    • 1995
  • Reaction-bonded SiC-Si material was fabricated by infiltration of Si melt into a mixture of $\alpha$-SiC and carbon at 175$0^{\circ}C$ under the vacuum atmosphere. Wear properties were analyzed by ball-on-plate wear tester, changing loading weight, sliding speed, sliding time and atmosphere, Results showed that the friction coefficient was decreased with increasing load and sliding velocity. The lowest friction coefficient of 0.05 was obtained under an oil atmosphere. The analysis of the wear surface indicated that the areas wehre particles were pulled out and where free silicon particles worn out preferentially serve as liquid reservoirs to decrease the wear resistance.

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Protecting the tracheal tube cuff: a novel solution

  • Abel, Adam;Behrman, David A.;Samuels, Jon D.
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.21 no.2
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    • pp.167-171
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    • 2021
  • We describe the successful insertion of a nasotracheal tube following repeated cuff rupture. The patient was a 55-year-old woman with a history of nasal trauma and multiple rhinoplasties, who underwent elective Lefort I osteotomy and bilateral sagittal split osteotomy for correction of skeletal facial deformity. During fiberoptic bronchoscope-guided nasal intubation after the induction of general anesthesia, the tracheal tube repeatedly ruptured in both nares, despite extensive preparation of the nasal airways. We covered the cuff with a one-inch tape, intubated to the level of the oropharynx, pulled the tracheal tube out through the mouth, and removed the tape. The tracheal tube was then backed out to the level of the uvula, and was successfully advanced.

The Research on Constructing Networks into Clusters;Focusing on the networks that support the growth of an enterprise (클러스터 내 성장지원 네트워크 구축에 관한 실증연구;대덕 첨단클러스터 성장지원 네트워크 중심으로)

  • Park, Chang-Hyeon;Park, Jun-Byung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.4
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    • pp.19-41
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    • 2007
  • This research has a goal which is suggesting the way of constructing 'Cluster' which mean scheming the commencement of an enterprise in an early stage. Now it is reorganized into a IT industry structure 'Time-to market growth' is burst as a big issue. in that point, this research analyze the core success factor which is drawing from the existing IT industrial complex, and then it will be used to draw up to the 'Idealistic growth-support Cluster' on the basis of it, we pulled out various issues about the Corporate in the early stage of its growth. Therefore, this research is focused on presenting the ideal network(net) by considering the Network that organizations and business in Cluster or the network including the factors linked organizations and business in Cluster. therefore, this research carried out three big analysis. from the case investigation we pulled out the core growth factor, and then we approached the analysis of net structure for making application to Network Analysis. and then we analyzed that the characteristics of the Network after measuring by on the basis of analyzing core growth factor. and especailly, this research carried out the Core analysis for recognition of Core- support-frame by base Centrality Test on the net which is composed of growth support organizations at each Business. Judging from this, we can help to make full use of resources for the network analysis in Cluster and establish the Network Strategy by Structure comparison between the structure of industry-Cluster and ideal Business-support networks on the basis of the analysis from the Core-success-factor

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Effect of Pull-out Property by Shape and Mechanical Property of Reinforcing Fiber on the Flexural Behavior of Concrete (보강섬유의 형상과 물성에 따른 인발특성이 콘크리트의 휨거동에 미치는 영향)

  • Kim, Hong-Seop;Nam, Jeong-Soo;Kim, Jung-Hyun;Han, Sang-Hyu;Kim, Gyu-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.5
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    • pp.41-50
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    • 2014
  • This study evaluated the bonding property of fiber and flexural behavior of fiber reinforced concrete. Amorphous steel fiber, hooked steel fiber and polyamide fiber was used for evaluation of bonding property and flexural behavior. As a result, the hooked steel fiber was pulled out from matrix when peak stress. However amorphous steel fiber occurred shear failure because bonding strength between fiber and matrix was higher than tensile strength of fiber. Polyamide fibers occurred significantly displacement to peak stress because of elongation of fiber. After that peak stress, fiber was cut off. Amorphous steel fiber reinforced concrete had a greater maximum flexural load compared with hooked steel fiber reinforced concrete because bonding performance between fiber and matrix was high and mixed population of fiber was many. However flexural stress was rapidly reduced in load-deflection curve because of shear failure of fiber. Flexural stress of hooked steel fiber reinforced concrete was slowly reduced because fiber was pulled out from the matrix. In the case of polyamide fiber reinforced concrete, flexural stress was rapidly lowered because of elongation of fiber. However flexural stress was increased again because of bonding property between polyamide fiber and matrix. The pull-out properties of the fiber and matrix has effect on the deformation capacity and flexural strength of fiber reinforced concrete.