• 제목/요약/키워드: Branch flow

검색결과 450건 처리시간 0.033초

비골 동맥 천공지 피판 (Peroneal Perforator Flap)

  • 정덕환;황준성
    • Archives of Reconstructive Microsurgery
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    • 제13권1호
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    • pp.29-35
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    • 2004
  • Materials and Methods: Total number of peroneal perforator flap is 14 cases, which 10 cases were man, 4 cases were woman. The range of age was 12 years old minimally and until 63 years old. The trauma was most common etiology, which was like traffic accidents, 9 cases. We confirmed tibialis anterior artery patency by doppler flow meter, angiography as preoperative evaluation. Results: 1. The success rate was 91%, that in 14 cases, 13 cases were succeded. 2. To obtain successful result of peroneal flap, one must have the anatomic concept for vascular pattern, 8 cases were between peroneus muscle and soleus muscle branch type but, 3 cases were through soleus muscle branch type, so we treated these cases by using soleus muscle including peroneal perforating branch not to injury perforating artery directly. 3. The pedicle size was between minimally $2{\times}2.5cm$ and maximally $6.5{\times}8.5cm$ so we could treat large recipient site. 4. The pedicle length was between minimally 3.2 cm and maximally 11.5cm, average 7.5 cm. 5. The diameter of perforating artery was estimated by inspection, that was about 0.2-0.5 cm Conclusion: The peroneal perforating artery flap has merits that we can approach in avascular zone and has wide movable range from foot to distal femur and little donor site mobidity and can harvest osteocutaneous flap. The weak point was the irregular anatomy of nutrient artery and not to contain sensory nerve.

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Modeling of Liquid Entrainment and Vapor Pull-Through in Header-Feeder Pipes of CANDU

  • Cho Yong Jin;Jeun Gyoo Dong
    • Nuclear Engineering and Technology
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    • 제36권2호
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    • pp.142-152
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    • 2004
  • The liquid entrainment and vapor pull-through offtake model of RELAP5/MOD3 had been developed for SBLOCA (Small Break Loss of Coolant Accident). The RELAP5/MOD3 model for horizontal volumes accounts for the phase separation phenomena and computes the flux of mass and energy through a branch when stratified conditions occur in the horizontal pipe. In the case of CANDU reactor, this model should be used in the coolant flow of 95 feeders connected to the reactor header component under the horizontal stratification in header. The current RELAP5 model can treat the only 3 directions junctions; vertical upward, downward, and side oriented junctions, and thus improvements for the liquid entrainment and vapor pull-through model were needed for considering the exact angles. The RELAP5 off-take model was modified and generalized by considering the geometric effect of branching angles. Based on the previous experimental results, the critical height correlation was reconstructed by use of the branch line connection angle and validation analyses were also performed using SET. The new model can be applied to vertical upward, downward and angled branch, and the accuracy of the new correlations is more improved than that of RELAP5.

Seismic response of smart nanocomposite cylindrical shell conveying fluid flow using HDQ-Newmark methods

  • Zamani, Abbas;Kolahchi, Reza;Bidgoli, Mahmood Rabani
    • Computers and Concrete
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    • 제20권6호
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    • pp.671-682
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    • 2017
  • In this research, seismic response of pipes is examined by applying nanotechnology and piezoelectric materials. For this purpose, a pipe is considered which is reinforced by carbon nanotubes (CNTs) and covered with a piezoelectric layer. The structure is subjected to the dynamic loads caused by earthquake and the governing equations of the system are derived using mathematical model via cylindrical shell element and Mindlin theory. Navier-Stokes equation is employed to calculate the force due to the fluid in the pipe. Mori-Tanaka approach is used to estimate the equivalent material properties of the nanocomposite and to consider the effect of the CNTs agglomeration on the scismic response of the structure. Moreover, the dynamic displacement of the structure is extracted using harmonic differential quadrature method (HDQM) and Newmark method. The main goal of this research is the analysis of the seismic response using piezoelectric layer and nanotechnology. The results indicate that reinforcing the pipeline by CNTs leads to a reduction in the displacement of the structure during an earthquake. Also the negative voltage applied to the piezoelectric layer reduces the dynamic displacement.

외측 심부 비골신경 포착 증후군의 증례 보고 (Rare Disease Entity of Dorsolateral Foot Pain: Lateral Branch of Deep Peroneal Nerve Entrapment Syndrome)

  • 나윤주;여승미;박진호;황지혜
    • Clinical Pain
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    • 제20권2호
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    • pp.122-126
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    • 2021
  • When a patient represents pain in foot, physician can easily overlook compression neuropathy of peripheral nerve as it is uncommon. Among nerve entrapment syndrome encountered in the foot, selective compression in lateral branch of deep peroneal nerve (DPN) is rare. We report a case of a patient with pain and dysesthesia in dorsolateral foot which turned out as lateral branch of deep peroneal nerve entrapment syndrome caused by talonavicular joint effusion. We would like to share diagnostic work up flow and conservative treatment courses. This case manifests the importance of the deep peroneal nerve and its branches in clinical setting of pain and ankle instability.

사출금형의 러너시스템 형상에 따른 균형 충전도 (Degree of Filling Balance according to Runner Shapes in Injection Mold)

  • 한동엽;정영득
    • 한국정밀공학회지
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    • 제25권10호
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    • pp.144-149
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    • 2008
  • Configuration of filling imbalance which is originated from imbalanced share rate of melt on runner is changed by runner layout, runner shape, material property, injection pressure, injection speed, melt temperature and mold temperature. In this paper, we conducted a study of runner layout and shape that are main factors of filling imbalance. Other factors such as the sharp corner effect and the groove corner effect are recently released were also considered. The results of study are showed that filling rate of between inside and outside cavity was influenced on shape of runner. Especially, this study suggests a new runner system for filling balance by adapting the two effects of unary branch type runner at multi cavity mold and theoretical investigated flow in the sharp corner type runner.

Capillary Hysteresis Model in Unsaturated Flow : State of the Art

  • Park, Chan-Kun;Sonu, Jun-Ho
    • Korean Journal of Hydrosciences
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    • 제4권
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    • pp.33-49
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    • 1993
  • The Purpose of this study is to classify existing hysteresis models and to discuss a possibility of a new type of the hysteresis model. The existing hysteresis models are classified into three types: the interpolation model, the scaling model and the domain model, of which only domain model is to simulate hysteresis curves based on the theoretical approach, It is useful to develop a hysteresis model that requires only one branch of hysteresis curves for the model calibration because obtaining hysteresis curves by experiments is expensive and time-concept by many investigators, however their models are not successful to accurately simulate real data of Rubicon Sandy Loam and Dune Sand. There is a possibility that a new model is based on the dependent domain concept considering the weighting factor, $P_a$($\theta$), which accounts for the pore blockage effect against air entry. Conclusively, a new model where the weighting factor $P_a$($\theta$) in Model III-1 (Mualem, 1984) reduces to a known variable through an appropriate method is an alternative model which required only one branch of main curves for the model calibration.

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다단계-병렬 흐름 생산시스템하에서의 제품별 로트 투입순서 결정

  • 김중순;강석호
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 1993년도 추계학술대회발표논문집; 서강대학교, 서울; 25 Sep. 1993
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    • pp.10-10
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    • 1993
  • 본 연구에서는 다품종(multiple products) 다단계(multi-stage) 흐름 생산시스템에서의 제품별 로트 투입순서결정무제를 다루었다. 다단계 흐름 생산시스템의 투입순서 결정문제에 대한 기존연구는 각 단계의 기계대수가 1대인 경우에 관한 것이 대부분이지만, 본 연구에서는 각 단계의 기계대수가 복수이고 각 제품의 생산량이 로트로 주어지며, 또한 각 단계마다의 이송이 로트로 이루어지는 것이 아니라 1단위로 이루어지는 생산시스템을 대상으로 하였다. 그리고 각 제품의 생산준비기간은 투입순서와 관계 없이 일정하며 앞 단계에서 제품이 도착하지 않더라도 생산준비는 먼저 수행될 수 있다고 가정하였다. 제품별 로트 투입순서 결정문제에서 사용된 성능평가기준(performance measure)은 총작업소요시간(makespan)이며 순열투입순서(permutation schedule)만을 대상으로 하였다. 결정기법으로는 투입순서 결정문제에서 효율적인 것으로 알려져 있는 분지한계법(Branch & Bound)이 사용되었으며 분지한계법에서 이용되는 부분투입순서(partial sequence)에 대한 하한값(lower bound)을 제시하였다. 제시된 기법을 사용하면 현실적인 크기의 제품별 로트 투입순서 결정문제를 적당한 시간내에 충분히 해결할 수 있을 것으로 보인다. 제시된 해법으로 해결된 수치예제가 주어져 있다.

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한강의 음해수치모형 (An Implicit Numerical Model of the Han River)

  • 최병호;고진석;안익장
    • 한국해안해양공학회지
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    • 제7권4호
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    • pp.346-354
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    • 1995
  • 전회의 양해법을 채택한 한강의 동수역학모형(최와 안, 1992)의 계산효율을 개선시키기 위해 지류변환방정식(Branch-transformation algorithm)을 적용한 음해모형을 적용하였다. 수립된 모형에 의해 정상유량 및 1925년, 1972년 및 1990년 홍수산정을 수행한 바, 만족할 만한 초기결과를 가졌다. 추후 모형의 개선을 위한 문제점 및 토의를 수록하였다.

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HPLC에 의한 가시오가피 및 오가피 중 Hyperin의 정량 (Determination of Hyperin in Acanthopanax senticosus and A. sessiliflorus by HPLC)

  • 이상현;정하숙;신국현;김박광
    • 약학회지
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    • 제48권4호
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    • pp.231-235
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    • 2004
  • A new high performance liquid chromatographic method was applied for the determination of hyperin in Acanthopanax senticosus and A sessiliflorus. The stationary phase used was $\beta$-Bondapak $C_{18}$ reverse-phase column and a mobile phase program was a gradient of acetonitrile and distilled water at a flow rate of 1.0 ml/min. Hyperin was detected at 210 nm, and the analysis was successfully carried out within 20 min. Hyperin was detected in the one year-grown and two years-grown stem of A senticosus (0.47 and 0.13 mg/g, respectively) and A sessiliflorus (0.14 and 0.03 mg/g, respectively). Hyperin was detected in the main and branch root of A sessiliflorus (0.30 and 0.09 mg/g, respectively). But there is no detection of hyperin in the main and branch root of A senticosus.

다기 전력 시스템 동적 안정도 향상을 위한 UPFC 제어기에 관한 연구 (a study on UPFC Controller for enhancing the Multi-machine Power System Dynamic Stability)

  • 김종현;정창호;김진오
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.93-95
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    • 2002
  • This paper presents the design of a Unified Power Flow Controller(UPFC) for enhancing the small signal voltage stability in the multi-machine power systems. Recently a lot of attention has been paid to the subject of dynamic stability. The paper deals with analysis of eigenvalue sensitivities with respect to parameters of UPFC Controller. The series branch of the UPFC is designed to damp the power oscillation during transients, while the shunt branch aims at maintaining the bus voltage. Comprehensive time-domain simulation studies using Pss/E show that the proposed robost UPFC controller can enhance the small signal stability efficiently in spite of the variations of power system operating conditions.

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