• Title/Summary/Keyword: 용적곡선

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A study on performance analysis of screw rotor profiles (스크류 로터 치형의 성능해석에 관한 연구)

  • 박세정;최상훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.627-631
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    • 1993
  • 스크류 압축기는 진동이 적고, 소형이면서 고효율을 유지하기가 용이하다는 특징을 가지고 있으며, 원통형 밀패용기 내에 암,수로터가 서로 반대 방향으로 맞물려 회전하면서, 로터홈과 케이싱 사이에 생기는 공간의 용적이 로터회전에 의해서 가스를 흡입, 압축, 배출하는 합축기 이다. 본 연구는 로터의 치형 함수의 기하학적성질 및 제한사항을 고려하여, 대칭 치형을 치수의 조합과, 원, 점, 직선, 타원을 사용하여 비대칭 치형을 설계하였다. 본 연구의 목적은 설계된 치형과 기존의 치형을 치형 형상의 변화에 따른 특성값 (실라인길이, 누설삼각형, 용적곡선, 흡입 및 토출 홈면적)의 변화에 대하여 연구함으로서 성능검토를 시도하였다.

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Effects of Pilocarpine on Pressure-Volume Curve of the Excised Rabbit Lung and Pulmonary Surfactant (Pilocarpine투여(投與) 가토폐장(家免肺臟)의 압력(壓力)-용적곡선(容積曲線) 및 폐포표면활성물질(肺胞表面活性物質)에 관(關)하여)

  • Lee, Seung-Jung;Chae, Soo-Hi;Lee, Suck-Kang
    • The Korean Journal of Physiology
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    • v.8 no.2
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    • pp.49-53
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    • 1974
  • A single dose of pilocarpine was subcutaneously injected into the rabbit in order to clarify the effects of cholinergic activities on the secretion of the pulmonary surfactant. The animal was sacrificed four hours after the injection, and the pressure-volume curve of the excised lung was obtained. The surfactant activities of the lung washings were also measured, and a comparison was made with the normal. The pressure-volume curve of the excised lung by the injection and ejection of air formed a loop (hysteresis) and the mean intra-alveolar pressure at 35 ml of air was 220 $mmH_20$ in the normal. The mean deflation curve of the pilocarpine treated rabbit lungs was shifted to the left compared with the normal. The surfactant activities were slightly increased than the normal. The above results suggest that pilocarpine stimulates the secretion of the pulmonary surfactant from the Type II alveolar epithelial cell.

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Intensity Modulation in Radiation Therapy (선량강도 조절법을 이용한 방사선치료)

  • 김성규;김명세
    • Progress in Medical Physics
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    • v.8 no.2
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    • pp.27-34
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    • 1997
  • In radiation therapy, the goal of three dimensional conformal radiation therapy(3DCRT) is to conform the apatial distribution of the prescribed radiation dose to the precise 3D configuration of the tomor, and at the same time, to minimize the dose to the surrounding normal tissues. To optimize treatment volume of tomor, treatment volume will be same tomor volume. Biological considerations need to be incorporated in the intensity modulation optimization process. Planning of intensity modulated treatment can irradiate more 20% in tomor compare to conventional 3DCRT. In lung cancer and rectal cancer, planning of intensity modulated treatment showed optimizing dose distribution.

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Effect of Betamethasone on the Pulmonary Pressure-Volume Curve in Unilateral Pneumonectomized Rabbits (Betamethasone이 일측폐장절제 가토폐장의 압력-용적곡선에 미치는 영향)

  • Lee, Young-Man;Lee, Suck-Kang
    • The Korean Journal of Physiology
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    • v.17 no.1
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    • pp.23-28
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    • 1983
  • In order to clarify the effect of steroid on the pulmonary pressure-volume curve in the pneumonectomized rabbit, the right side pneumonectomy was performed under general anesthesia with pentobarbital sodium and the remaining lung was excised on the fifth day after surgery. The intrapulmonic pressure in the excised left lung was measured at 20, 25, and 30 ml lung volume during inflation and deflation period. In the steroid treated group, the intrapulmonic pressure at 20, 25, and 30 ml lung volume during inflation was significantly decreased compared with intrapulmonic pressure of the control group. But in the pneumonectomy group the decreasing tendency of the pressure was observed. During deflation, the intrapulmonic pressure at 25 ml and 20 ml was not significantly different from the control group in pneumonectomy and steroid treated pneumonectomy group. And the lung weight was measured in each experimental group and also the lung weightbody weight ratio(L/B) was calculated. The lung weight was significantly increased in both pneumonectomy and steroid treated pneumonectomy group. Calculated L/B was increased significantly in both group. Above results suggest that steroid increases the secretion of pulmonary surfactant or affects the catabolic effect on protein metabolism of connective tissue in lung parenchyma.

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Design of a Gerotor Pump and Experimental Investigation of Its Volumetric Displacement Characteristics (제로터 펌프의 설계 및 배제용적 특성 실험)

  • Kim, Dae-Myoung;Kim, Sung-Dong;Gu, Ji-Suk;Oh, Sung-Jin;Ham, Young-Bog
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.11
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    • pp.1383-1389
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    • 2011
  • Gerotor-type volumetric displacement pumps are suitable for oil or water hydraulics. For this reason, many researchers have studied this topic. Gerotor pumps have been widely used in various fields. In this study, we designed a rotor profile based on an envelope of a family of curves. An analytic method for determining the volumetric displacement of the gerotor pump is verified by comparing a result obtained using CAD technology and an experimental result. Throughout the experiment, the flow rate performance was verified. In addition, we describe the design and volumetric displacement characteristics of the gerotor pump.

Localizd Failure and Fracture energies in Concrete under Compression (압축 응력 하에서의 콘크리트의 파괴거동)

  • 최석환
    • Magazine of the Korea Concrete Institute
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    • v.9 no.6
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    • pp.165-174
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    • 1997
  • 고강도 및 보통강도 콘크리트의 압축파괴 거동에 영향을 미치는 요소들 (재료의 강도, 시편의 세장비, 전단구속, 실험장치의 강성, 피드백 신호)에 관한 연구가 수행되었다. 피드백 신호로 자동 조절되는 유압 실험기계항에서 원주변형 피드백 신호를 사용하여 연화곡선을 구했다. 재하장치로부터의 단부 전단 구속을 줄이면 제한된 영역 안에서 재하방향 균형이 형성되고, 또한 연화곡선의 경사가 급해지고 파괴에너지도 작아진다. 이때 길이가 큰 시편에서 파괴에너지가 커지는 것은 안장과는 달리 단순균열이 형성되는 것이 아니고 , 파괴가 용적을 가진다는 것을 의미한다. 압축응력하의 국부 파괴는 재료특성이 아니므로, 단부 전단구속이 없더라도 재료적 특성으로서의 응력-변형도 곡선은 정하기 어렵다.

Rainfall Runoff Simulation Using Grid-Based Distributed Model for a Small Agricultural Reservoir Watershed (격자기반 분포형모형을 활용한 농업용 저수지유역의 홍수유출모의)

  • Jung, In-Kyun;Park, Jong-Yoon;Kim, Seong-Joon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.953-956
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    • 2009
  • 본 연구는 농업용저수지유역을 대상으로 분포형 강우-유출모형을 적용해 봄으로서 차후 본 연구대상유역의 분포형 강우유출모형을 이용한 설계홍수량 산정에 활용해 보기 위한 사전연구이다. 농업용저수지유역을 대상으로 모의하기 위하여 자동수위계를 통하여 저수지 수위자료가 주기적으로 기록되고 있는 계룡저수지 유역($15.4km^2$)을 선정하였으며, 주요 공간매개변수는 30m 격자해상도로 구축하였다. 관측유량자료는 수위-내용적-방류량 관계곡선에 의하여 수위변화에 따른 내용적 변화량을 유입량으로 가정하여 환산토록 하였으며, 곡선의 진동이 다소 작고 상태가 양호한 3개 강우사상을 대상으로 분석하였다. 대상유역의 2개 강우관측소(복룡, 반포)의 강우량을 IDW 방법에 의해 공간분포시켜 적용하였으며, 모형의 분석결과, 결정계수($R^2$)는 평균0.88, 용적보존지수(VCI)는 평균 0.14, 첨두유량의 상대오차 ($EQ_p$)는 평균 $0.11m^3/s$로 분석되었다.

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