• Title/Summary/Keyword: Suction Pressure

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Three Dimensional Vortex Behavior of LEX Delta Wing by Dynamic Stereo PIV (Dynamic Stereo PIV에 의한 델타형 날개에서의 3차원 와류 유동에 관한 연구)

  • Lee Hyun;Kim Mi-Young;Choi Jang-Woon;Choi Min-Seon;Lee Young-Ho
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.39-42
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    • 2003
  • Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modern air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras$(1280pixel\times1024pixel)$ were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.

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A Study on Design of Offshore Meteorological Tower (해상기상탑 설계에 관한 연구)

  • Moon, Chae-Joo;Chang, Young-Hak;Park, Tae-Sik;Jeong, Moon-Seon;Joo, Hyo-Joon;Kwon, O-Soon;Kwag, Dae-Jin;Jeong, Gwon-Seong
    • Journal of the Korean Solar Energy Society
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    • v.34 no.2
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    • pp.60-65
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    • 2014
  • A meteorological(met) tower is the first structure installed during the planning stages of offshore wind farm. The purpose of this paper is to design the met tower with tripod bucket type support structure and to install the sensors. The support structure consist of a central steel shaft connected to three cylindrical steel suction buckets which is more cheaper than monopile or jacket type. And the remote wind condition sensors and marine monitoring equipment, including adcp, pressure type tide gauge, wave height sensors, and scour sensors, remote power supply are installed. The manufactured met tower constructed on sea area which is in front of Gasa island. All of functions of met tower showed normal operation conditions and the wind data got by remote data collection system successfully.

A Simple, Reliable, and Inexpensive Intraoperative External Expansion System for Enhanced Autologous Structural Fat Grafting

  • Oranges, Carlo M.;Tremp, Mathias;Ling, Barbara;Wettstein, Reto;Largo, Rene D.;Schaefer, Dirk J.
    • Archives of Plastic Surgery
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    • v.43 no.5
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    • pp.466-469
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    • 2016
  • External volume expansion of the recipient site by suction has been proposed as a way of improving fat graft survival. The objective of this study was to present an innovative and simple intraoperative external expansion system to enhance small-volume autologous fat grafting (40-80 mL) and to discuss its background and its mechanism of action. In this system, expansion is performed using a complete vacuum delivery system known as the Kiwi VAC-6000M with a PalmPump (Clinical Innovations). The recipient site is rapidly expanded intraoperatively 10 times for 30 seconds each with a negative pressure of up to 550 mm Hg before autologous fat injection. During this repetitive stimulation, the tissues become grossly expanded, developing macroscopic swelling that regresses slowly over the course of hours following the cessation of the stimulus. The system sets various mechanisms in motion, including scar release, mechanical stimulation, edema, ischemia, and inflammation, which provide an environment conducive for cell proliferation and angiogenesis. In order to maintain the graft construct in its expansive state, all patients are encouraged postoperatively to use the Kiwi three times daily for one minute per session over the course of three days. The handling of this system is simple for both the patients and the surgeon. Satisfactory clinical outcomes have been achieved without significant complications.

Effects of a Ventilator-associated Pneumonia Prevention Program on Incidence Rate and Endotracheal Colonization (인공호흡기 관련 폐렴 예방 프로그램이 폐렴 발생률과 기관내 균집락화에 미치는 효과)

  • Song, Ui Rim;Kim, Sook Young
    • Korean Journal of Adult Nursing
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    • v.28 no.6
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    • pp.628-636
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    • 2016
  • Purpose: This study examined the effects of a program designed to prevent ventilator-associated pneumonia (VAP) on VAP rate and endotracheal colonization. The program focused on aspiration prevention and oral care. Methods: A nonequivalent control group post-test only design was utilized. One hundred patients admitted to a medical intensive care unit (MICU) or coronary care unit (CCU) were assigned to either a experimental group (n=50) or a control group (n=50). The participants were selected 48 hours following an endotracheal intubation. VAP prevention program given to the experimental group includes keeping the head of the bed to $30^{\circ}{\sim}45^{\circ}$ high, maintaining continuous endotracheal cuff pressure at 25 cm $H_2O$, performing endotracheal suction before change position, and providing oral care with 0.1% chlorhexidine every four hours. The control group received usual care. Data were analyzed using t-test, $x^2$ test, Mantel-Haenszel $x^2$ and Cox proportional harzard regression model. Results: The experimental group showed a lower VAP rate than the control group although the difference was not statistically significant ($x^2=0.79$, p=.375). The experimental group showed lower colonization in tracheal secretion than the control group ($x^2=14.59$, p<.001). Conclusion: Results showed that a VAP prevention program is effective in reducing colonization of tracheal secretion. Therefore, VAP prevention programs are recommended as an ICU nursing intervention.

침지형 분리막을 사용한 오수처리

  • 최광호
    • Proceedings of the Membrane Society of Korea Conference
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    • 1998.06a
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    • pp.113-133
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    • 1998
  • In activated sludge process, sludge settling condition is affected by organic loading rate or operation condition, and if settling condition is getting worse, it is common that overall process fails due to wash-out of biomass causing low concentration in the aeration tank. Also activated sludge process has such several problems as requiring large area, consuming a lot of power and producing large volume of sludge. Increased public concern over health and the environment combined with a strong desire to reduce capital, operating and maintenance costs, have created a need for innovative technologies for building new high quality effluents which vail meet 21st century crkeria. MBR(Membrane Bioreactor) process consists of a biological reactor and ultrafiltration(UF) membrane system that replaces the conventional clarifier of an activated sludge process. The main operating advantages of this system are that the quality of the effluent is independent of the settleability of the mixed liquor and that the effluent is free of suspended solids in any operating condition. It is possible to eliminate clarifier and to reduce the volume of aeration tank because it can afford to accumulate high biomass concentration in the bioreactor(20, 000~30, 000mg/L), which would not be possible in a conventional activated sludge process. Therefore, this process reduces overall treatment plant area. In addition to those advantages, Longer SRT condition enables higher sludge digestion in MBR process so the sludge volume produced is 50 to 70% lower than that of conventional activated sludge process There are two kinds of MBR process according to the allocations of membrane. One is cross flow type MBR of which module is located outside of the bioreactor and mixed liquor is driven into the membrane module. The other is submerged type MBR process of which module is submerged in the bioreactor and mixed liquor is generally sucked from the lumen side. addition to that the cake layer is often removed by the uplifting flow of bubbling air. A submerged MBR process is superior to a crossflow MBR in regard to the power consumption because suction pressure of a submerged MBR is generally lower than that of a crossflow MBR which has recirculation pump. A submerged MBR, therefore, has the potential to be applied to small wastewater treatment plants that need low cost treatment systems.

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Effect of Relative Position of Vane and Blade on Heat/Mass Transfer Characteristics on Stationary Turbine Blade Surface (베인과 블레이드 사이의 상대위치 변화에 따른 터빈 블레이드 표면에서의 열/물질전달 특성)

  • Rhee, Dong-Ho;Cho, Hyung Hee
    • The KSFM Journal of Fluid Machinery
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    • v.8 no.4 s.31
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    • pp.27-38
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    • 2005
  • The present study investigated the effect of relative position of the blade on blade surface heat transfer. The experiments were conducted in a low speed wind tunnel with a stationary annular turbine cascade. The test section has a single turbine stage composed of sixteen guide vanes and blades. The chord length of the blade is 150 mm and the mean tip clearance of the blade is $2.5\%$ of the blade chord. The Reynolds number based on blade inlet velocity and chord length is $1.5{\times}105$ and mean turbulence intensity is about $3\%$. To investigate the effect of relative position of blade, the blade at six different positions in a pitch was examined. For the detailed mass transfer measurements, a naphthalene sublimation technique was used. In general, complex heat transfer characteristics are observed on the blade surface due to various flow characteristics, such as a laminar flow separation, relaminarization, flow acceleration, transition to turbulence and tip leakage vortices. The results show that the blade relative position affects those heat transfer characteristics because the distributions of incoming flow velocity and turbulence intensity are changed. Especially, the heat transfer pattern on the near-tip region is significantly affected by the relative position of the blade because the effect of tip leakage vortex is strongly dependent on the blade position. On the pressure side, the effect of blade position is not so significant as on the suction side surface although the position and the size of the separation bubble are changed.

The Study on the Development of Ozone Water Diffusion Device by Ozonated Olive Oil Mix Ratio that will Increase (올리브 오일의 오존화 혼합비율을 높여주는 오존수 확산장치개발에 관한 연구)

  • Kim, Duck-Sool
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.4
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    • pp.688-693
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    • 2014
  • This study is to increase the utilization of the ozonated water generator to make it easier to take advantage of the ozone water in the world today, there will be to develop a system that operates in one motion. Furthermore, olive oil and ozone is reacted with the wish to apply to the manufacturing technology. In the case of many existing products ozone generator driven mostly non-ozone system. In the case of ozone, but handwriting is implied general way pressure ozone gas leakage risks of suction force to the pump, it is the case of the challenge by using the injector, and limit the generation of ozone and ozone inhalation according to whether the water inlet leakage of existing products risk due to minimized. Despite the disadvantages of the injector system was found the effectiveness of the ozonated water production unit injector system used in this study to maintain the microbiological disinfection performance.

Flow Structure of Conical Vortices Generated on the Roof of a Rectangular Prism (직사각형 프리즘 상면에서 발생되는 원추형 와의 유동구조)

  • Kim, Gyeong-Cheon;Ji, Ho-Seong;Seong, Seung-Hak
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.5
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    • pp.713-721
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    • 2001
  • Characteristics of the conical vortices on the roof corner of a rectangular prism have been investigated by using a PIV(Particle Image Velocimetry) technique. The Reynolds number based on the free stream velocity and the height of the model was 5.3$\times$10$^3$. The mean, instantaneous velocity vector fields, vorticity fields, and turbulent kinetic energy distribution were measured for two different angles of attack, 30$^{\circ}$and 45$^{\circ}$. The PIV measurements clearly observed not only the conical main vortex and the secondary vortex but also the tertiary vortex which is firstly reported in this paper. Asymmetric formation of the corner vortex for the case of 30$^{\circ}$angle of attack produces relatively the high magnitude of vorticity and turbulent kinetic energy around the bigger vortex which generates the peak suction pressure on the roof. Fairly symmetric features of the roof vortex are observed in the case of 45$^{\circ}$angle of attack, however, the dynamic characteristics are proved to be asymmetric due to the rectangular shape of the roof.

A Research of Prehospital 119 Emergency Medical Service for Stroke Patients (병원 전 뇌졸중 환자의 구급의료 실태 분석)

  • Song, Hyun-Mok;Roh, Sang-Gyun
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.14-20
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    • 2012
  • This study analyzes the influencing factors of prehospital 119 Emergency Medical Service for Stroke Patients in prehospital. From July, 2010 to June, 2011, 123 patients were diagnosed with Stroke in Emergency Medical Center. Among 123 patients, the prehospital assessment rates were as follows : blood pressure checked 73.2 %, pulse checked 73.2 %, respiratory checked 64.2 %, $SpO_2$ checked 79.7 %, pupil reflex test 88.6 %, Electrocardiogram checked 14.6 %, blood sugar checked 19.5 %. Prehospital emergency medical care, Oropharyngeal airway insertion 2.4 %, Manual airway maneuvers 17.1 %, endotracheal intubation 2.7 %, oxygen supply 35.4 %, and suction and intravenous fluid therapy 0 %. The property of mental status evaluation by 119 Emergency Medical Service was nearly perfect, but the patients assessment and emergency medical care were not.

Application of Modified Vacuum Assisted Closure with Silver Materials in Chronic Infected Wound (만성 감염성 창상에 대한 변형 음압요법과 은이온 제재의 이용)

  • Park, Gun Wook;Jeong, Jae Ho
    • Archives of Plastic Surgery
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    • v.35 no.4
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    • pp.393-399
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    • 2008
  • Purpose: Chronic infected wounds sustained over 4 weeks with exposed tendon or bone are difficult challenges to plastic surgeons. Vacuum assisted closure (VAC) device has been well used for the management of chronic wounds diminishing wound edema, reducing bacterial colonization, promoting formation of granulation tissue and local blood flow by negative pressure to wounds. But Commercial ready-made VAC device might have some difficulties to use because of its high expenses and heavy weight. So we modified traditional VAC device with silver dressing materials as topical therapeutic agents for control of superimposed bacterial wound infection such as MRSA, MRSE and peudomonas. Methods: We designed the modified VAC device using wall suction, 400 cc Hemovac and combined slow release silver dressing materials. We compared 5 consecutive patients' data treated by commercial ready-made VAC device(Group A) with 11 consecutive patients' data treated by modified VAC device combined with silver dressing materials(group B) from September 2004 to June 2007. Granulation tissue growth, wound discharge, wound culture and wound dressing expenses were compared between the two groups. Results: In comparison of results, no statistical differences were identified in reducing rate of wound size between group A and B. Wound discharge was significantly decreased in both groups. Modified VAC device with silver dressing materials showed advantages of convenience, cost effectiveness and bacterial reversion. Conclusion: In combination of modified VAC device and silver dressing materials, our results demonstrated the usefulness of managing chronic open wounds superimposed bacterial infection, cost effectiveness compared with traditional VAC device and improvement of patient mobility.