• Title/Summary/Keyword: Tearing

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A Clinical Study of Patent Ductus Arteriosus (동맥관개존증의 임상적 고찰)

  • 이선희
    • Journal of Chest Surgery
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    • v.21 no.4
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    • pp.672-680
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    • 1988
  • Munro is generally considered the first person to have demonstrated, in 1888, in an infant cadaver, the feasibility of dissection and ligation of a persistently patent ductus arteriosus. In august, 1938, Robert Gross reported first successful division and suture of the patent ductus of 7 year old girl. Interruption of a ductus is one of the most satisfactory and curative operations in the field of surgery for congenital heart disease. Seventy-eight consecutive cases of closure of patent ductus arteriosus were operated from June 1980 to June 1988 in the department of thoracic and cardiovascular surgery in Maryknoll Hospital. Retrospective clinical analysis of the patients were 1. There were 24 males, 54 females. 2. The age range of the patients were from 7 months to 32 years with the mean age 9.8 years. 3. Chief complaints of the patients were frequent URI[70.5%], dyspnea on exertion[36.9%], palpitation[10.3%], but 15 patients[19.2%] had no subjective symptoms. 4. Continuous machinery murmur could be heard at the 2nd or 3rd intercostal space on the left sternal border in 66 patients[84.6%]. The other 12 patients made systolic murmur. 5. Radiographic findings of the Chest P-A were cardiac enlargement in 55 patients[70%], enlargement of pulmonary conus and/or increasing density of pulmonary vascularity in 68 patients[87%]. 6. Electrocardiographic findings of the patients were within normal limit in 23 patients[36%], LVH in 38 patients[48.7%], RVH in 7 patients[9%], biventricular hypertrophy in 5 patients[6%]. 7. Cardiac catheterization performed in 62 patients. Mean Qp/Qs=2.5, mean pulmonary arterial pressure=45 mmHg. 8. 73 patients were operated through left posterolateral thoracotomy: Closure of the ductus by ligation in 64 cases, division with suture in 6 cases, and division with aortopatch in 3 cases. Ligation through median sternotomy under cardiopulmonary bypass were 5 cases. 9. There was no death associated with operation, but one case was experienced with intraoperative tearing of ductus resulting in massive bleeding. The other complications were transient hoarseness in 2 patients, chylothorax in 2 patients.

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Mode III Fracture Toughness of Single Layer Graphene Sheet Using Molecular Mechanics (분자역학을 사용한 단층 그래핀 시트의 모드 III 파괴인성)

  • Nguyen, Minh-Ky;Yum, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.2
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    • pp.121-127
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    • 2014
  • An atomistic-based finite bond element model for predicting the tearing mode (mode III) fracture of a single-layer graphene sheet (SLGS) is developed. The model uses the modified Morse potential for predicting the maximum strain relationship of graphene sheets. The mode III fracture of graphene under out-of-plane shear loading is investigated with extensive molecular mechanics simulations. Molecular mechanics is used for describing the displacements of atoms in the area near a crack tip, and linear elastic fracture mechanics is used outside this area. This work shows that the molecular mechanics method can provide a reliable and yet simple method for determining not only the shear properties of SLGS but also its mode III fracture toughness in the armchair and the zigzag directions; the determined mode III fracture toughness values of SLGS are $0.86MPa{\sqrt{m}}$ and $0.93MPa{\sqrt{m}}$, respectively.

Pulp vitality and coronal discoloration following traumatic injuries (치아외상 후 치아 변색과 치수 생활력의 변화)

  • Yoon, Tae-Sun;Kong, Hyung-Gyu;Kim, Eui-Seong
    • Restorative Dentistry and Endodontics
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    • v.35 no.6
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    • pp.492-496
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    • 2010
  • Coronal discoloration is a common sequela to traumatic injuries. In subluxation cases, although the injury is not strong enough to rupture the apical vessels, discoloration may appear by tearing thin walls or occluding small capillaries. In absence of infection pulpal regeneration can occur, and as a result discoloration may completely or partially subside. But judging pulpal status by coronal discoloration can be dangerous and it may lead to unnecessary treatment. This case presents coronal discoloration and recovery following traumatic injury of maxillary anterior teeth. In diagnosing traumatized teeth routine cold tests or electric pulp tests are known to be unreliable, but with the aid of ultrasound doppler imaging, assessing pulp vitality of traumatized teeth can be more accurate.

Estimation of fracture toughness of cast steel container from Charpy impact test data

  • Bellahcenea, Tassadit;Aberkane, Meziane
    • Steel and Composite Structures
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    • v.25 no.6
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    • pp.639-648
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    • 2017
  • Fracture energy values KV have been measured on cast steel, used in the container manufacture, by instrumented Charpy impact testing. This material has a large ductility on the upper transition region at $+20^{\circ}C$ and a ductile tearing with an expended plasticity before a brittle fracture on the lower transition region at $-20^{\circ}C$. To assess the fracture toughness of this material we use, the $K_{IC}$-KV correlations to measure the critical stress intensity factor $K_{IC}$ on the lower transition region and the dynamic force - displacement curves to measure the critical fracture toughness $J{\rho}_C$, the essential work of fracture ${\Gamma}_e$ on the upper transition region. It is found, using the $K_{IC}$-KV correlations, that the critical stress intensity factor $K_{IC}$ remains significant, on the lower transition region, which indicating that our testing material preserves his ductility at low temperature and it is apt to be used as a container's material. It is, also, found that the $J_{\rho}-{\rho}$ energetic criterion, used on the upper transition region, gives a good evaluation of the fracture toughness closest to those found in the literature. Finally, we show, by using the ${\Gamma}_e-K_{IC}$ relation, on the lower transition region, that the essential work of fracture is not suitable for the toughness measurement because the strong scatter of the experimental data. To complete this study by a numerical approach we used the ANSYS code to determine the critical fracture toughness $J_{ANSYS}$ on the upper transition region.

Numerical Simulation of Cone Penetration Tests in Sand Ground Using Critical State Mohr Coulomb Plasticity Model (한계상태 Mohr Coulomb 소성 모델을 활용한 콘관입시험의 수치적 모사)

  • Woo, Sang Inn;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.35 no.2
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    • pp.37-51
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    • 2019
  • This study focuses on the numerical simulations of the cone penetration tests in a sand ground. The mechanical responses of sand were described using the modified Mohr Coulomb plasticity model based on the critical state soil mechanics. In the plasticity model, the dilatancy angle was not a constant, but a function of the distance to the critical state line from the current state of void ratio and mean effective stress. To simulate cone penetration tests numerically, this study relied on Lagrangian finite element method under the axisymmetric condition. To enable penetration of the cone penetrometer without tearing elements along the symmetric axis, the penetration guide concept was adopted in this study. The results of numerical simulations on the calibration chamber cone penetration tests had good agreement with the experimental results.

Predicting Arachnoid Membrane Descent in the Chiasmatic Cistern in the Treatment of Pituitary Macroadenoma

  • Ko, Hak Cheol;Lee, Seung Hwan;Shin, Hee Sup;Koh, Jun Seok
    • Journal of Korean Neurosurgical Society
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    • v.64 no.1
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    • pp.110-119
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    • 2021
  • Objective : Preoperative prediction of the arachnoid membrane descent in pituitary surgery is useful for achieving gross total removal and avoiding cerebrospinal fluid leakage resulting from tearing of the arachnoid membrane in the chiasmatic cistern. In this study, we analyzed the patterns of arachnoid membrane descent during or after pituitary tumor surgery and identified the factors related to this descent. Methods : Analysis was restricted to pituitary macroadenomas not extending into the third ventricle or over the internal carotid artery. To minimize confounding factors, patients who underwent revision surgery, those who had a torn arachnoid during operation or small medial diaphragma sellae (DS) opening, and subtotal resections were excluded. We enrolled 41 consecutive patients in this retrospective analysis. The degree of arachnoid descent was categorized using intraoperative videos. Preoperative magnetic resonance findings, including tumor height, suprasellar extension, and variables including DS area and medial opening size, tumor composition, and displacement of the pituitary stalk and gland were evaluated to determine their correlations with arachnoid membrane descent. Results : Arachnoid membrane descent was significantly correlated with DS area and medial opening size. Based on T2-weighted images (T2WI) magnetic resonance (MR) images, tumor composition was significantly associated with arachnoid membrane descent. Other factors were not significantly correlated with arachnoid membrane descent. Conclusion : T2WI of tumor composition and preoperative MR imaging of DS area and medial opening provided valuable information regarding arachnoid membrane descent. These parameters may serve as fundamental measures to facilitate complete resection of pituitary macroadenomas.

A Japanese American Female Writer's Tearing Down the Barriers: Lydia Minatoya's Talking to High Monks in the Snow and The Strangeness of Beauty. (재미 일본인 여류작가의 경계 허물기 : 리디아 미나토야의 『설중 고승여담』과 『미의 기묘함』)

  • Kim, Ilgu
    • English & American cultural studies
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    • v.10 no.2
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    • pp.1-27
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    • 2010
  • By taking the form of a fictional autobiography, a Japanese American woman writer Lydia Minatoya tries to solve the inexpressible confliction which Japanese Americans experience in their living in America. In her first published fiction, Talking to High Monks in the Snow, the writer faithfully tries to follow the Japanese I-story tradition where meandering of personal petit histories and frequent self-pities are constructed without solid action, characters and plot. Here appear many accidental others whom function as significant yet fleeting subalterns. In contrast, in the second fiction, The Strangeness of Beauty published seven years later, the I-narratives undergoes some drastic transformations by authorial intrusion, dramatic and haiku styles, and appearances of actorial agents. Just working as an invisible yet important stagehand (kuroko in Japanese) behind the stage of life, the author now handles her own self-inquiry through more controllable distance and maturity as directors or photographers often do. However, despite achieving dramatic actions and artistic elegance mainly thanks to her adoption of western masterpieces's grand narratives, Minatoya seems to stop in the midway in her tallying work of fiction with fact by delaying the larger imaginable conflict through which the temporarily gained autonomy can be turned into a disaster anytime. Nonetheless, the reader feels relieved and encouraged after recognizing the fragile Asian female self's transformation as a new, flexible and autonomous self by her unwavering contact with two contrasting cultures and providing silent minority female characters with gradually stronger and uncannier voices.

Separation Phenomenon Occurring during Charpy Impact test of API X80 Linepipe Steels (API X80 라인파이프강의 샤르피 충격 시험 시 발생하는 파열 현상 연구)

  • Shin, Sang Yong;Hong, Suckmin;Bae, Jin-ho;Kim, Kisoo;Lee, Sunghak
    • Korean Journal of Metals and Materials
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    • v.47 no.3
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    • pp.155-168
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    • 2009
  • In this study, microstructural investigation was conducted on the separation phenomenon occurring during Charpy impact tests of API X80 linepipe steels. Particular emphasis was placed on the role of microstructural phases present in the API X80 steels such as acicular ferrite, bainite, and hard secondary phases. Detailed microstructural analysis of fractured impact specimens showed that highly elongated bainite worked as prior initiation sites for separations, and that the number and length of separations increased with increasing volume fraction of bainite. In the steels having high work hardenability, tearing-shaped separations were found because the hammer-impacted region was seriously hardened during the impact test, which led to the reduction in the impact toughness. As the test temperature decreased, the tendency of separations increased, but separations were not observed when the cleavage fracture prevailed at very low temperatures. Thus, the minimization of the formation of bainite and secondary phases in the steels would be beneficial for preventing or minimizing separations because separations deteriorated low-temperature impact toughness.

Development of virtual upcycling fashion design based on 3-dimensional digital clothing technology (디지털 클로딩 기술 기반 가상착의 업사이클링 패션디자인)

  • Chen, Tianyi;Yang, Eun Kyoung;Lee, Younhee
    • The Research Journal of the Costume Culture
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    • v.29 no.3
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    • pp.374-387
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    • 2021
  • The purpose of this study is to develop up-cycling fashion design methods centered on discarded denim material for the study of original up-cycling design methods. Up-cycling fashion design work was developed using digital clothing technology. This is a recent hot topic among sustainable fashion design methods. Up-cycling fashion design expression methods (categorized as dismantlement, collages, dépaysement, grafting, weaving, and tearing) were centered on design methods. These methods create various three-dimensional modeling effects in planar forms, whereby five pieces can be applied to the fabric and digitally produced. The results are as follows: First, the use of discarded denim fabric for the development of up-cycling fashion design pieces enabled the recycling of existing resources, provided solutions to environmental pollution problems, and provided expansion opportunities for design processes for sustainable fashion products that expand the design value of denim products and their utility. Second, new eco-friendly fashion designs that attempt to achieve diversity in modern fashion trends could be presented through formative contemporary fashion produced by up-cycling work products. Third, up-cycling fashion design work is expected to provide opportunities for eco-friendly fashion design methods. This will expand the value of sustainable fashion design by recycling simple waste materials through the use of three-dimensional digital clothing technology and further through the presentation of expanded life cycles that extend product planning, production, and life cycles.

Comparative study of external-intenal morphological shape in origins and hybrids for Glycyrrhizae Radix et Rhizoma (감초의 기원 및 교잡종 외내부형태 성상 비교연구)

  • Kim, Young-Sik;Park, Chun-Geon;Choi, Goya;Chang, Jae-Ki;Lee, Jeong-Hoon;Ju, Young-Sung
    • The Korea Journal of Herbology
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    • v.34 no.5
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    • pp.1-12
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    • 2019
  • Objectives : The consumption of licorice is large in Korea, but domestic production is insufficient due to the lack of adaptability. This study aimed to provide a morphological basis for adding interspecific hybrid licorice with improved adaptability to pharmacopoeia. Methods : This study was to establish identification criteria for the original plants, external and internal morphology of the authentic herbal medicines (Glycyrrhiza uralensis, G. glabra and G. inflata), market products and artificially interspecific hybrid forms of licorice. For this purpose, previous studies were investigated and visual and histological observations were carried out. We focused on the internal morphology by microscopic observation for securing objectivity. Finally, we proposed the identification keys for precise classification of each part. Results : 1) Original plant : Licorice species in the compendium were distinguished by the number of leaflets, presence of hair on the fruit, curvature and swelling of the fruit. 2) External morphology : Licorice species were distinguished by degree of powderiness, tearing gap, radial structure in the cross section and existence of protrusion of outer epidermis. 3) Internal morphology : Licorice species were distinguished by the degree of development of phloem fiber bundle, development of obliterated sieve, whether the secondary medullary ray are branched. In the case of interspecific hybrids, the characteristics of both species used for hybridization were mixed in all observation methods. Conclusions : These results suggest that the interspecific crossbred licorice is suitable for the pharmacopoeial standard. Therefore, it can be applied as a herbal medicine through additional supplementary study.