• 제목/요약/키워드: thin-walled

검색결과 698건 처리시간 0.028초

홀스타인 초산우에서 우측 자궁각의 부분무형성 일례 (Segmental Aplasia of the Right Uterine Horn in a Primiparous Holstein Cow)

  • 김일화;강현구;허태영;이혜림;모인필
    • 한국임상수의학회지
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    • 제29권5호
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    • pp.427-430
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    • 2012
  • 번식장애의 병력을 가진 3세 홀스타인 초산우가 분만 후 180일에 직장검사에 의해 자궁축농증으로 예비 진단되었다. 초음파검사 결과, 우측 자궁각의 전반 부분이 액체로 팽만, 자궁각 기저부 결손과 자궁각의 전반 부분은 치밀한 조직 띠에 의해 자궁체에 연결되어 있음을 보여 주었다. 좌측 자궁각은 정상적인 형태를 나타내었다. 사후 육안 검사는 초음파 검사 소견을 확증시켜 주었다. 벽이 얇아진 우측 자궁강 내에 진한 적갈색 점액이 차여 있었으며, 조직 병리 검사에 의해 이 부위에서 자궁소구 및 자궁샘이 관찰되지 않았다. 본 증례는 최종 우측 자궁각의 부분무형성으로 판명되었다.

절곡된 단면을 갖는 얇은 판요소 콘크리트 충전 각형강관 기둥의 부착거동 (Bond Behavior of Thin-Walled Rectangular Profiled Steel Sheet Concrete Short Columns)

  • 윤현도;박완신;한병찬
    • 한국구조물진단유지관리공학회 논문집
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    • 제9권1호
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    • pp.233-241
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    • 2005
  • 본 연구는 콘크리트로 충전한 절곡된 단면을 갖는 각형강관 기둥의 부착특성을 매입인발(Pull-out) 시험을 통해 평가하였다. 시험체는 단면 $250{\times}250mm$의 강관 단면에 콘크리트를 충진한 PSSC기둥으로 표준형(P), 사다리꼴(I), 직사각형(II), 역사다리꼴(III)의 4가지 형태(Fig. 3)와, 부착길이에 대한 폭비 (L/D=2.0, 2.5, 3.0) 단면의 폭두깨비(d/t)으로 설정하여 총 13로 하였다. 실험결과 얇은 판요소 절곡된 강관과 콘크리트의 부착거동은 일반적인 부착거동과 유사하게 화학적 부착과 기계적 부착의 형태로 거동하였으며, 부착응력은 강판의 절곡형태가 (equation omitted)순으로 높게 나타났다. 또한 (equation omitted)타입 시험체의 경우에는 얇은 판요소를 갖는 단면임에도 불구하고 AIJ에서 제시하고 있는 $0.147N/mm^2$의 값을 상회하는 것으로 나타나 부착응력을 고려할 수 있을 것으로 판단되었다.

$CO_2$ Laser를 이용한 점액종의 치료 (TREATMENT OF MUCOCELE USING THE $CO_2$ LASER : CASE REPORT)

  • 이인천;김종수;권순원
    • 대한소아치과학회지
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    • 제27권4호
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    • pp.485-489
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    • 2000
  • 점액종은 점액소를 함유한 낭종으로서, 인접 조직으로 선분비물이 유출되거나 소타액선관이 폐쇄되어서 형성된다. 다른 질환과의 감별진단 후 완전히 낭종을 제거해야만 완전 치유가 이루어지며, 절개 배농이나 흡입은 단지 일시적인 방법일 뿐 반드시 재발한다. $CO_2$ Laser를 이용한 구강영역에서의 치료 시 장점으로는 우수한 지혈효과, 우수한 시야확보, 인접조직 손상의 최소화 뿐만 아니라, 작은 혈관과 림프관을 봉쇄하는 능력이 있어 창상치유시 나타나는 염증과정의 초기 증상들을 차단하기 때문에 술후 감염 감소, 술 후 종창 및 동통 감소 등이 나타나며, 반흔조직 및 창상수축의 감소 등이 있다.

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Pulmonary Pneumatocele in a Pneumonia Patient Infected with Extended-Spectrum β-Lactamase Producing Proteus mirabilis

  • Ryou, Sung Hyeok;Bae, Jong Wook;Baek, Hyun Jin;Lee, Doo Hyuk;Lee, Sang Won;Choi, Gyu Ho;Han, Kyu Hyung;Kim, Se Weon;Kim, Hyunbeom;Hong, Goohyeon
    • Tuberculosis and Respiratory Diseases
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    • 제78권4호
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    • pp.371-374
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    • 2015
  • Pulmonary pneumatoceles are air-filled thin-walled spaces within the lung and are rare in adult cases of pneumonia. We report the case of a 74-year-old male who was admitted with a cough and sputum production. He had been treated with oral dexamethasone since a brain tumorectomy 6 months prior. Contrast-enhanced computed tomography (CT) of the chest revealed a large pneumatocele in the right middle lobe and peripheral pneumonic consolidation. Bronchoalveolar lavage was performed; cultures identified extended-spectrum ${\beta}$-lactamase (ESBL) producing Proteus mirabilis. A 4-week course of intravenous ertapenem was administered, and the pneumatocele with pneumonia resolved on follow-up chest CT. To the best of our knowledge, this is the first reported case of pulmonary pneumatocele caused by ESBL-producing P. mirabilis associated with pneumonia.

소성역체결 볼트의 체결력과 마찰계수에 관한 연구 (Study on the Clamping Force and the Friction Coefficient in a Bolt tightened up to the Plastic Range)

  • 손승요;신근하
    • 전산구조공학
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    • 제7권3호
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    • pp.133-141
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    • 1994
  • 강도활용을 극대화한 볼트의 소성역체결시 볼트의 항복은 볼트에 발생한 인장응력과 너트 나사산과의 접촉면에서 오는 마찰토오크에 의한 전단응력과의 조합에 의한 영향을 받는다. 볼트는 최소단면적인 나사부중 너트와 물리지 않은 여우나사부에서 먼저 항복을 일으킨다. 볼트재료는 대체로 항복과 더불어 소성경화를 보이며 그 정도는 고강도재료에서 인장강도의 10%정도이다. 본 연구에서는 소성역체결시의 거동해석을 변형도증분이론에 의거 해석하였다. 항복은 최소단명이 원통의 표면에서 시작되며 이를 두께가 얇은 원통으로 취급하였다. 항복의 전파는 이들 얇은 원통이 체결이 진행됨에 따라 순차적으로 항복에 이르는 것으로 보고 이 얇은 원통들을 항복시키는데 필요한 축력과 토오크를 합하여 체결종료시의 볼트축력과 (나사면마찰) 토오크로 하였다. M10미터 가는 나사를 계산과 실험에 사용하였다. 축력과 마찰토오크의 마찰계수에 대한 변화관계를 보여주는 그래프와 더불어 실험에서 사용한 볼트의 설계보조 선도를 제시하였다. 이 설계보조용 선도는 실험실에서 얻어진 토오크계수와 마찰계수와의 관계를 그린 것으로 윤활, 포면처리등 현장조건에 따라 달라진 마찰계수를 적절히 취급하는데 효과적으로 활용이 가능하다.

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Large deflection behavior and stability of slender bars under self weight

  • Goncalves, Paulo B.;Jurjo, Daniel Leonardo B.R.;Magluta, Carlos;Roitman, Ney;Pamplona, Djenane
    • Structural Engineering and Mechanics
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    • 제24권6호
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    • pp.709-725
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    • 2006
  • In this paper the buckling and post-buckling behavior of slender bars under self-weight are studied. In order to study the post-buckling behavior of the bar, a geometrically exact formulation for the non-linear analysis of uni-directional structural elements is presented, considering arbitrary load distribution and boundary conditions. From this formulation one obtains a set of first-order coupled nonlinear equations which, together with the boundary conditions at the bar ends, form a two-point boundary value problem. This problem is solved by the simultaneous use of the Runge-Kutta integration scheme and the Newton-Raphson method. By virtue of a continuation algorithm, accurate solutions can be obtained for a variety of stability problems exhibiting either limit point or bifurcational-type buckling. Using this formulation, a detailed parametric analysis is conducted in order to study the buckling and post-buckling behavior of slender bars under self-weight, including the influence of boundary conditions on the stability and large deflection behavior of the bar. In order to evaluate the quality and accuracy of the results, an experimental analysis was conducted considering a clamped-free thin-walled metal bar. As this kind of structure presents a high index of slenderness, its answers could be affected by the introduction of conventional sensors. In this paper, an experimental methodology was developed, allowing the measurement of static or dynamic displacements without making contact with the structure, using digital image processing techniques. The proposed experimental procedure can be used to a wide class of problems involving large deflections and deformations. The experimental buckling and post-buckling behavior compared favorably with the theoretical and numerical results.

이축성과 위상차의 영향을 고려한 이축 하중하에서 구멍 주위에서의 피로 균열 발생 방향 예측 (Prediction of Fatigue Crack Initiation Direction around a Hole under Biaxial Loads Considering Phase Difference and Biaxiality)

  • 허용학;박휘립;김동진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.156-161
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    • 2004
  • To predict the direction of the fatigue crack initiated from a hole under various types of biaxial fatigue loads with different phase difference and biaxiality, fatigue parameters were investigated. Axial and torsional biaxial fatigue loads were selected with the respective combination of five different phase differences of 0, 45, 90, 145 and 180 degrees and five biaxialities of 0, $1/{\sqrt{3}}$, 1, ${\sqrt{3}}$, ${\infty}$. Directions of the fatigue crack initiation around the hole were found to approach to the circumferential direction of the specimen with increment of the phase difference for fatigue tests with phase differences less than $90^{\circ}$. Whereas directions for tests with phase differences greater than $90^{\circ}$ went away from the circumferential direction and those were symmetric to the directions for tests with phase difference less than $90^{\circ}$. With increase of biaxilities, the fatigue crack initiated more apart from the circumferential direction of the specimen. These crack initiation direction were predicted using maximum tangential stress range and maximum shear stress range obtained at far-field and around the hole. Comparing these two stress parameters, The crack initiation direction can be successfully explained by using the direction of the maximum tangential stress range obtained around the hole and at far-field.

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Clomifen 호르몬제 복용후 호흡곤란이 악화된 환자에서의 미만성 망상형 간질성 폐침윤 (Diffuse Reticular Interstitial Infiltrations in the Patient with Worsening Exertional Dyspnea after Clomifen Hormonal Therapy)

  • 박형천;김영삼;김세규;정경영;신동환;이홍렬;장준;김성규;이원영
    • Tuberculosis and Respiratory Diseases
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    • 제42권4호
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    • pp.624-628
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    • 1995
  • Lymphangioleiomyomatosis is a rare disease which afflicts young women of childbearing age. We experienced a 32-year-old female who was admitted because of worsening exertional dyspnea after hormonal therapy with Clomifen for five months and intermittent hemoptysis. Chest PA showed diffuse ground glass appearance with some reticular infiltrations. High resolution CT scan showed multiple small thin walled cysts distributed homogeneously throughout the entire lung. Pulmonary function test showed characteristic obstructive pattern despite the restrictive interstitial pattern of chest radiography. Thoracoscopic lung biopsy specimen showed abnormal proliferation of smooth muscle cells in the walls of lymphatic vessels, bronchioles, and pulmonary vessels typical of pulmonary lymphangioleiomyomatosis. Hormonal therapy with medroxyprogesterone was initiated.

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다발성 낭성 유두상 폐선암 1예 (A Case of Papillary Adenocarcinoma Presenting with Multiple Cysts)

  • 전수연;김유진;경선영;안창혁;이상표;박정웅;정성환;조은경;성연미;김나래
    • Tuberculosis and Respiratory Diseases
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    • 제68권2호
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    • pp.93-96
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    • 2010
  • A 23-year old woman was admitted to our hospital with hemoptysis. The chest X-ray showed reticulonodular opacity and multiple cysts throughout the entire lung field. The chest CT scan revealed numerous bilateral cysts with various sizes, some of them with thickened walls. An open lung wedge resection was performed. The resected specimen showed scattered small nodules, 0.3 to 0.6 cm in size. Microscopically, each nodule was composed of atypical glands with an occasional papillary architecture spreading to the alveolar septa, which were morphologically consistent with a papillary adenocarcinoma with a bronchioloalveolar carcinoma growth pattern. Immunochemically, the tumor cells were negative for the S-100 protein. The patient was diagnosed with an adenocarcinoma of the lung. A variety of diseases can produce or mimic multiple, thin-walled cysts in the lung. Lung cancer with multiple cysts is quite rare. Nevertheless, adenocarcinoma should be a diagnostic consideration. We report a case of a multiple cystic adenocarcinoma of the lung.

Full-scale tests and finite element analysis of arched corrugated steel roof under static loads

  • Wang, X.P.;Jiang, C.R.;Li, G.Q.;Wang, S.Y.
    • Steel and Composite Structures
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    • 제7권4호
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    • pp.339-354
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    • 2007
  • Arched Corrugated Steel Roof (ACSR) is a kind of thin-walled steel shell, composing of arched panels with transverse small corrugations. Four full-scale W666 ACSR samples with 18m and 30m span were tested under full and half span static vertical uniform loads. Displacement, bearing capacities and failure modes of the four samples were measured. The web and bottom flange in ACSR with transverse small corrugations are simplified to anisotropic curved plates, and the equivalent tensile modulus, shear modulus and Poisson's ratio of 18m span ACSR were measured. Two 18 m-span W666 ACSR samples were analyzed with the Finite Element Analysis program ABAQUS. Base on the tests, the limit bearing capacity of ACSR is low, and for half span loading, it is 74-75% compared with the full span loading. When the testing load approached to the limit value, the bottom flange at the sample's bulge place locally buckled first, and then the whole arched roof collapsed suddenly. If the vertical loads apply along the full span, the deformation shape is symmetric, but the overall failure mode is asymmetric. For half span vertical loading, the deformation shape and the overall failure mode of the structure are asymmetric. The ACSR displacement under the vertical loads is large and the structural stiffness is low. There is a little difference between the FEM analysis results and testing data, showing the simplify method of small corrugations in ACSR and the building techniques of FEM models are rational and useful.