• Proceedings of the KOR-BRONCHOESO Conference
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• 1996.04a
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• pp.82-82
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• 1996

후두전적출술은 상부 소화관의 연속성을 변형시킴으로써, 식도운동의 장애를 가져올 수 있으며, 술 후에 연하곤란을 호소하는 경우는 10% 가량 된다. 본 연구의 목적은 식도내압검사를 통하여, 후두전적출술이 상부식도괄약근의 휴지기와 최대 압력에 어떠한 변화를 주는가 및 술 후 인두와 상부식도괄약근의 조화성 여부와, 만일 상부식도괄약근의 기능에 변화가 생긴다면, 그 영향이 식도체부 및 하부식도괄약근의 운동성에 어떠한 영향을 주는지를 알아보기 위함이다. 식도내압검사는 8개의 내관을 가진 폴리에틸렌 도관으로, 후두전적출술을 받은 환자군 14명과 정상인 12명을 대상으로, stational pull-through 방법으로 시행하였다. 환자군에서 상부 식도괄약근은, 휴지기 압력, 최대 수축압력, 이완정도, 괄략운동의 조화성 및 괄약근의 길이 등이, 정상 대조군 보다 의미있게 감소되었다. 환자군에 있어서 식도체부의 운동성은 주로 근위부 식도체부에서, 수축력, 수축기간 및 연동파의 전파시간이 대조군에 비하여 의미있게 감소되었고, 연동운동시 동시 수축도 3례에서 관찰되었다. 하부 식도괄약근의 기능은 환자군과 대조군이 의미있는 차이를 보이지 않았다.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.79-85
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• 2003

Experimental investigations are performed for the rarefied gas flows in a multi-stage disk-type drag pump. The pump considered in the present study consists of grooved rotors and stators. The flow-meter method is adopted to calculate the pumping speed. Compression ratios and pumping speeds for the nitrogen gas are measured under the outlet pressure range of 0.13∼533 Pa. The present experimental data show the leak-limited value of the compression ratio in the molecular transition region. The rotational speed of the pump is 24,000rpm, and nitrogen is used as a test gas. The pumping characteristics of various drag pumps are performed. The inlet pressures are measured for various outlet pressures of the test pump. The ultimate pressures for zero throughput are measured for three-stage, two-stage and single-stage disk-type, respectively.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.125-135
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• 1994

저자는 두 개하악장애환자의 보존적 치료에 따른 압력통각역치오 휴식시 근전도의 변화를 평가하기 위하여 여성 환자 21명을 대상으로 치료전후에 각각 동통의 정도를 유추척도로 나타내었고 편이개구량을 측정하였으며 교근과 전측두근의 압력통각역치와 휴식시 근전도를 조사하였다. 두 개하악장애의 병력이나 증상이 없는 21명의 정상 여학생을 대조군으로 교근과 전측두근의 압력통각역치와 휴식시 근전도를 측정하여 환자군과 비교한 결과 다음과 같은 결론을 얻었다. 1. 보존적 치교이후 동통과 최대편이개구량은 개선되었다. 2. 보존적 치료이후 압력통각역치는 증가하였고 휴식시 근전도는 감소하였다. 3. 압력통각역치나 휴식시 근전도의 좌우차이는 없었다. 4. 압력통각역치와 휴식시 근전도사이에는 약한 음의 상관관계가 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.115-122
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• 2020

This study aimed to improve the reliability of the assurance pressure of a gun barrel due to the difference between the US Standard and Korean Standard. In addition, the reliability was found to differ according to the maximum pressure of the Ammunition, so restrictions are expected. During the development of the new bullet, the maximum pressure of the bullet was approximately 3,000 psi higher than the assurance pressure of the gun barrel. To solve this problem, the reliability of the cannon was analyzed when the assurance pressure of the gun barrel increased. First of all, the technical data from overseas were reviewed to check for cases of increased assurance pressure, and tests were performed to determine if it could withstand high pressure through a verification firing test. Finally, the simulation analyzed the stability of the recoil buffer. The study found no abnormal results in all items, suggesting that an increase in the assurance pressure for a gun barrel was possible. This study is expected to be used as basic data for future reliability studies of similar equipment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.379-383
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• 2011

Electro-osmotic pumps were fabricated by using two types of porous glass frits. The performance of these pumps was characterized in terms of maximum flow rate, current, and pressure using deionized water and 1 mM sodium tertraborate decahydrate buffer. Maximum flow rate and current when ROBU porous glass frits were used were higher than those when DURAN porous glass frits were used because of the high porosity of the ROBU glass frits. However, the maximum pressure when ROBU glass frits were used was similar to that when DURAN glass frits were used. The therrmodynamic efficiency of a pump with ROBU porous glass frits is approximately twice that of a pump with DURAN porous glass frits. Further, the maximum flow rate at maximum current in the case of ROBU porous glass frits is high. However, it is lower than the maximum pressure at maximum current in the case of DURAN porous glass frits. Further, in this study, we also verified the effectiveness of ROBU glass frits when high flow rate is required and of DURAN glass frits when a high pressure is required.

• Water for future
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• v.27 no.2
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• pp.111-120
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• 1994

In this experimental research, the maximum scour depth at pier was studied. The model of the pier of San Gye bridge in the Bocheong stream was set for experimental pier scour studies. Several model verification processes were conducted through the roughness comparisons between model and prototype, pursuring scour depth variations with time depending upon channel bed variation, the comparison of the ratio between falling velocities and shear velocities in the model and prototype, and the comparison of pier scour between experimental data and field measuring data. The experiments were conducted in the free flow conditions and pressure flow conditions. The maximum scour depth at piers in the pressure flow conditions is twice as much as compared to the free flow conditions. Also, the maximum scour depth variations are indicated in the figures based on the Froude numbers, opening ratios, water depths and approaching angles in the free surface flow conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.351-354
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• 2006

In the present work, performance analysis of fuel feed and transfer system for Smart UAV was conducted. For the fuel feed system, it was verified that minimum and maximum pressure requirements at the fuel inlet of engine were satisfied. For the fuel transfer system, design variables of jet pump were derived and performance was verified for the maximum acceleration flight condition by using ESDU design guide and flowmaster code.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.627-632
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• 1997

FLECHT-SEASET 실험을 이용하여 냉각재상실사고시 Reflood에 대한 TRAC-PF1 전산코드의 예측 능력을 평가하였다. FLECHT-SEASET 실험 장치는 3.657m(12 ft) 높이 161개 전열 봉으로 이루어 져 있으며, 다양한 재관수율, 계통압력, 초기 피복재온도, 재관수온도 노심내 반경방향 출력분포 둥의 조건에 따라 수행된 실험이다. TRAC-PF1은 비균질 비평형 이상유동 열수력(Nonhomogeneous Non-equilibrium Two-Fluid Hydrodynamic)모델을 사용하고 원자로 압력용기는 3차원으로 모델할 수 있는 최적전산코드로서, 이 평가 계산에는 HP Version이 사용되었다. 본 연구에서는 재관수율 변화에 따라 달라지는 연료봉 최대 피복재온도와 Quench 시간에 대한 TRAC-PF1 전산코드의 예측 능력을 중점적으로 평가하였다. 계산 결과 TRAC-PF1은 최대 피복재온도는 약 20-100$^{\circ}$K 낮게, Quench 시간은 실험치와 비교하여 약 40-150초 정도 늦게 예측하는 것으로 나타났는데, 재관수율이 낮을수록 최대피복재 온도는 낮게, Quench 시간은 늦게 예측하는 경향을 보이고 있다. 또한 재관수율이 3 in/sec 이상에서 노심 상부가 일찍 Quenching 되는 것으로 계산되는데, 이는 노심상부 열전달 Regime의 부적절한 계산이 원인으로 보인다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.236-241
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• 2002

진공노즐방식의 파종기로 파종작업할 경우 박과채소의 대목으로 사용되고 있는 대립종자들의 최대파종율을 얻기위하여 참박, 특토좌, 흑종호박 종자에 대한 파종시험을 실시하였다. 1) 적정한 노즐구경과 홉착부압은 참박종자가 1.5mm, 7.97kPa, 특토좌종자가 1.5mm, 10.63kPa, 흑종호박종자가 2.0mm, 5.31kPa과 1.5mm, 13.28kPa로 나타났다. 2) 최적작동조건에서 참박종자, 특토좌종자 및 흑종호박 종자의 최대 파종율은 97.6%, 98.8% 및 97.6%로 나타났다. 3) 종자가 커지고 무거워짐에 따라 노즐의 구경이 큰 것이 유리한 것으로 나타났는데, 대목으로 사용되는 종자에서는 1.5mm노즐을 범용으로 사용가능하다는 결론을 얻었다. 4) 노즐개수가 많아지면 부착압력이 낮을 경우에는 파종율에 차이가 있었지만 부착압력이 높아지게 되면 파종율의 차이는 약간 낮아졌다. 5) 참박, 특토좌, 흑종호박 종자의 최대파종율을 나타내는 흡착부압 P = η.4W/$\pi$d$^2$로 나타낼 수 있고 여유계수 η ≒ 10으로 나타났다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.70-75
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• 2006

The cabin pressurization system response should be consistent with the design limits such as the cabin pressure schedule, the pressure regulation tolerance, the maximum rate of pressure change during normal and abnormal operation and the maximum cabin air inflow rate change. In this paper, the results of pressure loss analysis and flight test for cabin pressurization system of T-50 advanced trainer are introduced. The pressure tolerance at unpressurized condition using calculated exit area of pressurization components through pressure loss analysis is predicted. Pressurization components of D company are selected and the predicted pressure tolerance is in good agreement with flight test results. Finally, T-50 pressurization system is verified by some flight tests of T-50 advanced trainer to comply with various pressurization design criteria of MIL-E-18927.