• 제목/요약/키워드: Ejection

검색결과 736건 처리시간 0.02초

방사성핵종 심혈관조영술의 기능적영상화에 대한 고찰 (Comparison of functional Images obtained by radionuclide angiocardiography and gated blood pool scan)

  • 범희승;김지열
    • 대한핵의학회지
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    • 제25권2호
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    • pp.186-191
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    • 1991
  • Radionuclide cardiac studies lend themselves exceptionally well to functional imaging. This is especially true for gated blood pool scan (GBP). Making functional images is also possible in radionuclide angiocardiography (RNAC). In this study we tried to validate the functional images obtained from RNAC by comparing it with GBP. Twenty three patients (16 patients with coronary artery diseases, 5 with hypertensive heart diseases, and 2 with nonspecific chest pains) underwent simultaneous RNAC and GBP at the same position (LAO $45^{\circ}$). From both studies, global ejection fraction, regional ejection fraction, phase image, amplitude image, stroke image, paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox images of RNAC are very similar to those of GBP. However, amplitude and stroke images are different. Regional ejection fractions of the left ventricular base, maximum ejection and maximum filling rates obtained from RNAC are significantly different from those of GBP. In conclusion, albeit all of functional images of RNAC is not same as GBP, regional walt motions and global left ventricular function are expected to be successfully analyzed by phase and paradox image and ejection fraction.

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미세 수관 노즐의 전기유체역학적 수적 분사특성 (Electrohydrodynamic Water Droplet Ejection Characteristics from a Micro-Water-Nozzle)

  • 문재덕
    • 전기학회논문지
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    • 제59권9호
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    • pp.1632-1637
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    • 2010
  • A micro-water-nozzle, as one of a cooling means of micro-electronic devices, has been proposed and investigated. The I-V characteristics of the micro-water-nozzle and effect of applied voltage on the meniscus formation and deformation and ejection processes of de-ionized water on the micro-water-nozzle tip have been investigated. The water ejection processes, such as a drop formation, a drop deformation, a dripping, a cone jet, and an atomization, were taken place on the micro-water-nozzle tip by the electrohydrodynamic forces acted by the DC and AC high voltages applied on the meniscus of the micro-water-nozzle tip. The I-V characteristics of the micro-water-nozzle-to-plate electrode system were different from that of the same metal-point electrode system, due to the meniscus formation and water droplet ejection at the nozzle tip. The positive and negative DC and AC high voltages showed the water droplets ejection, the ejection rates of 1.8, 1.5 and 1.2 g/h respectively, which, however, showed that the proposed micro-water-nozzle-to-plate electrode system could be used as one of an effective pumping means.

방사성동위원소 심조영술상 심전도게이트 일회통과법을 이용한 우심실 박출계수 (Right Ventricular Ejection Fraction using ECG-Gated First Pass Cardioangiography)

  • 문영희;이해규;이성용;박석민;정수교;임정익;박용휘;신경섭;김영균;권순석
    • 대한핵의학회지
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    • 제27권1호
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    • pp.135-139
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    • 1993
  • Radionuclide cardioangiography has been widely applied and has played major roles in non-invasive assessment of cardiac function. Three techniques, first-pass, gated first and gated equilibrium methods, have commonly been used to evaluate right ventricular ejection fraction which usually abnormal in the patients with cardiopulmonary disease. It has been known that the gated first pass method is the most accurate method among the three techniques in assessment of right ventricular ejection fraction. The radionuclide right ventricular ejection fraction values were determined in 13 normal subjects and in 15 patients with chronic obstructive pulmonary disease by the gated first pass method and compared with those of the first pass method because there ha,j been no published data of right ventricular ejection fraction by the gated first pass method in Korea. The values of right ventricular ejection fraction by the gated first pass method were compared with the detas from the pulmonary function test performed in the patients with chronic obstructive pulmomary disease. The results were as follows: 1) The values of right ventricular ejection fraction by the gated first pass method were $50.1{\pm}6.1%$ in normal subjects and $38.5{\pm}8.5$ in the patients with chronic obstructive pulmonary disease. There was statistically significant difference between the right ventricular ejection fraction of each of the two groups (p < 0.05). 2) The right ventricular ejection fraction by the gated first pass method was not linearly correlated with $FEV_1$, VC, DLCO, and FVC as well as $P_aO_2$ and $P_aCO_2$ of the patients with chronic obstructive pulmonary disease. We concluded that right ventricular ejection fraction by the gated first pass method using radionuclide cardioangiography may be useful in clinical assessment of the right ventricular function.

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Precise Distribution Simulation of Scattered Submunitions Based on Flight Test Data

  • Yun, Sangyong;Hwang, Junsik;Suk, Jinyoung
    • International Journal of Aeronautical and Space Sciences
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    • 제18권1호
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    • pp.108-117
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    • 2017
  • This paper presents a distribution simulation model for dual purpose improved conventional munitions based on flight test data. A systematic procedure for designing a dispersion simulation model is proposed. A new accumulated broken line graph was suggested for designing the distribution shape. In the process of verification and simulation for the distribution simulation model, verification was performed by first comparing data with firing test results, and an application simulation was then conducted. The Monte Carlo method was used in the simulations, which reflected the relationship between ejection conditions and real distribution data. Before establishing the simulation algorithm, the dominant ejection parameter of the submunitions was examined. The relationships between ejection conditions and distribution results were investigated. Five key distribution parameters were analyzed with respect to the ejection conditions. They reflect the characteristics of clustered particle dynamics and aerodynamics.

유도탄 사출시 비산물로 인한 인체 안전과 영향성에 관한 연구 (A Study of the Human Body Safety and Effectiveness for Scattering Objects on Missile Ejection Round)

  • 정성학;윤효석
    • 한국안전학회지
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    • 제29권4호
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    • pp.180-183
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    • 2014
  • The purpose of this study is to assess for scattering object for the missile ejection round due to analysis of the human body effectiveness safely. To achieve this goal the measurement method of scattering objects by comparative 2 measurement methods studied, the risk of scattering of the object is evaluated. Result of this study, applied in Europe and Japan, based on the safety criteria for the human body effectiveness when missile ejection round. data showed is not effectiveness to the operator's body safely. Data showed that satisfies the safety criteria for missile ejection round in Europe and Japan through the similarity for the case studies. In case of these safety criteria does not exist regulation in South Korea, this study will be referred as guidelines are considered.

2,000lb급 장착물의 분리분석을 위한 지상투하시험 (Static Ejection Test for Separation Analysis of 2,000lb-Class Store)

  • 신병준;조영희;김민수
    • 한국군사과학기술학회지
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    • 제26권4호
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    • pp.344-351
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    • 2023
  • Static ejection tests were conducted using the 2,000lb-Class Store to provide ejector model for the store separation simulation. In this study, static ejection test device for 2,000lb-class store was constructed and reaction force applied to store was measured over time. In addition, the trajectories of the ejected store were obtained using photogrammetry and compared with the simulations using developed ejector model. The results of the static ejection test were analyzed to determine the cartridge-orifice combination to be used for store separation. Flight tests were performed by applying the analysis results and verified that the store was safely separated from the aircraft.

활공탄의 안전분리 해석을 위한 지상투하시험 (Ground Ejection Tests for the Safe Separation Analysis of a Gliding Bomb)

  • 이기두;이인원;박영근;백승욱;정나현;정상준
    • 한국항공우주학회지
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    • 제41권6호
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    • pp.502-508
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    • 2013
  • 새로이 개발된 유도키트를 장착한 모의 활공탄에 대하여 지상투하시험을 수행하였다. 사출형 분리장치의 카트리지와 오리피스 조합에 따른 사출력을 측정한 결과, 오리피스 직경이 클수록 사출력이 크게 작용하였으며, 투하된 후 날개 전개장치를 비롯하여 탄의 내부에 탑재된 시험 장치들의 정상 작동을 확인하였다. 또한 영상자료로부터 활공탄의 피치각은 전방과 후방의 사출력 분포 즉 카트리지와 오리피스 조합에 따라 증가 또는 감소하는 것으로 분석되었다.

정익 후연의 냉각유체분사를 포함한 축류터빈단의 성능해석 (Performance Analysis of an Axial Flow Turbine Stage with Coolant Ejection from Stator Trailing Edge)

  • 김동섭;김재환;노승탁
    • 대한기계학회논문집B
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    • 제23권7호
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    • pp.831-840
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    • 1999
  • In this work, an aerothermodynamic calculation model for cooled axial flow turbine blades with trailing edge ejection is suggested and a mean line performance analysis of a turbine stage with nozzle cooling is carried out. A unique model regarding the interaction between coolant and main gas is proposed, while existing correlations are adopted to predict viscous loss and blade outflow angle. The interactions considered are the heat transfer from main gas to coolant and the temperature and pressure losses by the mixing of two streams due to the trailing edge coolant ejection. For a stator blade without ejection, trailing edge loss calculated by the trailing edge analysis is compared with that calculated by loss correlation. The effect of heat transfer effectiveness of coolant passage on the mixing loss is analyzed. For a model turbine stage with nozzle cooling, parametric analyses are carried out to investigate the effect of main design variables(coolant mass flow ratio, temperature and ejection area) on the stage performance.

향요법마사지가 제왕절개술 산모의 기분, 유즙사출반사, 유즙 면역글로불린A에 미치는 효과 (Effect of Aromatherapy Massage on the Mood, the Milk ejection Reflex, and the Immunoglobulin A of the Breast Milk of Mothers with a Cesarean Section Delivery)

  • 이성희
    • 대한간호학회지
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    • 제30권5호
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    • pp.1357-1367
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    • 2000
  • The purpose of this quasi-experimental study was to explore the effect of aromatherapy massage on the mood, the milk ejection reflex, and the immunoglobulin A of the breast milk of mothers who gave birth through a Cesarean section delivery. Twenty mothers who had Cesarean section were selected as an experimental group, and twenty-two were in the control group. Lavander and Rosemary oil mixed with Jojova carrier oil was used to massage the back, both axillar and breasts. Aromatherapy massage was done once a day for 20 minutes by the researcher. Each session consisted of 4 minutes for warm-up, 14 minutes for massage and 2 minutes for closure. The levels of IgA within the breast milk was analyzed by an immunoturbidimeter assay (Cobas INTEGRA, Roche, Swiss) before and after aromatherapy massage. Mood and milk ejection reflex were measured by self-reports at the same time. The data were analyzed using SPSS 7.5 and the hypotheses were tested by ANCOVA and the Pearson coefficient correlation. The results were as follows : 1) Score of mood increased significantly after the use of aromatherapy massage. 2) Score of milk ejection reflex increased significantly after the use of aromatherapy massage. 3) Level of IgA of breast milk did not change significantly after the use of aromatherapy massage.4) After the use of aromatherapy massage, there wasn't any correlation among mood, milk ejection reflex, and level of IgA of breast milk. In conclusion, the results suggest that aromatherapy massage is an effective nursing intervention to enhance the mood and the milk ejection reflex and to increase the rate of breastfeeding in the breastfeeding mothers under stresses like a Cesarean section.

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항공기 장착 무장의 투하 안정성 검증을 위한 지상무장분리시험 (Ground Ejection Tests to verify the Safe Separation of an Aircraft Mounted Store)

  • 이종홍;최석민;이민형;이철;정재원
    • 한국항행학회논문지
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    • 제22권2호
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    • pp.70-75
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    • 2018
  • 항공기에 장착하는 무장은 실제 항공기에 장착하기 전에 안전 분리가 이루어졌음을 검증하기 위해 지상에서 무장분리시험을 실시해야 한다. 본 연구에서는 더미유도탄으로 지상에서투하 안정성을 검증하기 위한 지상무장분리시험을 실시하였다. 지상무장분리시험의 필수장비인 무장분리장치는 공압으로 동작하며 압력이 크고, 오리피스 직경이 클수록 유도탄을 밀어내는 사출력이 크게 발생한다. 무장분리장치의 봄베 압력과 오리피스 직경을 변경하여 더미유도탄의 투하 움직임을 고속카메라로 계측하였고 투하변위, 투하속도를 분석하였다. 실제 비행하는 항공기에서 무장 투하 해석시 기초 데이터를 제공할 수 있고, 추후 개발되는 항공기 무장의 지상무장분리시험 수행시 유용할 것으로 생각한다.