• Title/Summary/Keyword: active pressure

Search Result 959, Processing Time 0.024 seconds

A case study of extraplanar molecular gas in a Virgo spiral using the ALMA

  • Lee, Bumhyun;Chung, Aeree
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.2
    • /
    • pp.61.3-62
    • /
    • 2016
  • NGC 4522 is a spiral galaxy located in the Virgo cluster which appears to be undergoing active ram pressure stripping due to the intracluster medium (ICM). What makes this galaxy special is the extraplanar CO gas, some of which coincides with the extraplanar $H{\alpha}$ patches. As one of the few cases where the interstellar molecular gas is thought to have been pushed out from the stellar disk by the ICM, this galaxy provides an opportunity to study the impact of ICM pressure on the dense/star forming gas and its fate in the extraplanar space after stripping. In order to probe detailed molecular gas properties inside and outside the stellar disk and the associated star formation activities, we have observed NGC 4522 in 12CO (1-0) and 13CO (1-0) using the ALMA. We have targeted two regions, one around the center of the galaxy and one centered on the peak of the extraplanar CO, detecting both lines in both regions. Particularly, this is the first case where 13CO gas has been detected outside the stellar disk in a galaxy undergoing ram pressure stripping. In this work, we present preliminary results from the ALMA observations and discuss the evolution of molecular gas properties and star formation activities inside and outside the stellar disk.

  • PDF

Paint Removal of Airplane & Water Jet Application

  • Xue, Sheng-Xiong;Chen, Zheng-Wen;Ren, Qi-Le;Su, Ji-Xin;Han, Cai-Hong;Pang, lei
    • International Journal of Fluid Machinery and Systems
    • /
    • v.7 no.3
    • /
    • pp.125-129
    • /
    • 2014
  • The paint removal and recoating are the very important process in airplane maintenance. The traditional technology is to use the chemical way corroding the paint with paint remover. For changing the defects, corrosion & pollution & manual working, of the traditional technology, the physical process which removes the paint of airplane with 250MPa/250kW ultra-high pressure rotary water jetting though the surface cleaner installed on the six axes robot is studied. The paint layer of airplane is very thin and close. The contradiction of water jetting paint removal is to remove the paint layer wholly and not damage the surface of airplane. In order to solve the contradiction, the best working condition must be reached through tests. The paint removal efficiency with ultra-high pressure and move speed of not damaged to the surface. The move speed of this test is about 2m/min, and the paint removal efficiency is about $30{\sim}40m^2/h$, and the paint removal active area is 85-90%. No-repeat and no-omit are the base requests of the robot program. The physical paint removal technology will be applied in airplane maintenance, and will face the safety detection of application permission.

The Effects of the Boundary Shapes on the Structural-acoustic Coupled System (다양한 경계 형상에 따른 구조-음향 연성계의 음향특성)

  • 김양한;서희선
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.14 no.8
    • /
    • pp.718-725
    • /
    • 2004
  • If a wall separates the bounded and unbounded spaces, then the wall’s role in transporting the acoustic characteristics of the two spaces is not well defined. In this paper, we attempted to see how the acoustic characteristics of two spaces are really affected by the spatial characteristics of the wall. In order to understand coupling mechanism, we choose a finite space and a semi-infinite space separated by the flexible or rigid wall and an opening. A volume interaction can be occurred in structure boundary and a pressure Interaction can be happened in the opening boundary. For its simplicity, without loosing generality, we use rather simplified rectangle model instead of generally shaped model. The source impedance is presented to the various types of boundaries. The distributions of pressure and active intensity are also presented at the cavity- and structure-dominated modes. The resulting modification, shifts of modal frequencies and changing of standing wave patterns to satisfy both coupled boundary conditions and governing equations, are presented.

The Effects of Education of Chronic Diseases Management for the Elderly Group in Parts of Seoul (서울지역 일부 노인집단에 대한 만성질환관리 교육의 효과)

  • Chang, Hyun-Sook;Lee, Sae-Young
    • Health Policy and Management
    • /
    • v.20 no.3
    • /
    • pp.157-172
    • /
    • 2010
  • This study was conducted to evaluate the effects of health-behavioral change for the elderly group after community based education of chronic diseases management. We measured self recognition of health status, medication administration of hypertension and diabetes, regular check for blood pressure and blood sugar level, recognition of body indicators (weight, hight, blood pressure, blood sugar etc), knowledge level for chronic diseases management and smoking and alcohol habitation before and after education of chronic diseases management for participants. The subjects of this study consist of 432 people with community-dwelling Seoul citizen being active churches. Education programs designed essential parts of fundamental chronic diseases management, physical exercises for health promotion, diet and nutrition etc. All data collection completed for 5 months from Aug. 2008 to Dec. 2008 by trained surveyors via interview survey. The data obtained were analyzed using descriptive statistics, Wilcoxon Singed Rank test, McNemar test and Paired t-test. The results showed that self recognition of health status, knowledge level for chronic diseases management, recognition of body indicators were statistically significantly increased after the education of chronic diseases management. Also, blood pressure were statistically significantly decreased in elderly with hypertension and blood sugar were statistically significantly decreased in elderly of high-risk group. Based on these results, it was suggested that preventive education policy of chronic diseases management should be considered with priority coming true for successful aging society.

CFD simulation of compressible two-phase sloshing flow in a LNG tank

  • Chen, Hamn-Ching
    • Ocean Systems Engineering
    • /
    • v.1 no.1
    • /
    • pp.31-57
    • /
    • 2011
  • Impact pressure due to sloshing is of great concern for the ship owners, designers and builders of the LNG carriers regarding the safety of LNG containment system and hull structure. Sloshing of LNG in partially filled tank has been an active area of research with numerous experimental and numerical investigations over the past decade. In order to accurately predict the sloshing impact load, a new numerical method was developed for accurate resolution of violent sloshing flow inside a three-dimensional LNG tank including wave breaking, jet formation, gas entrapping and liquid-gas interaction. The sloshing flow inside a membrane-type LNG tank is simulated numerically using the Finite-Analytic Navier-Stokes (FANS) method. The governing equations for two-phase air and water flows are formulated in curvilinear coordinate system and discretized using the finite-analytic method on a non-staggered grid. Simulations were performed for LNG tank in transverse and longitudinal motions including horizontal, vertical, and rotational motions. The predicted impact pressures were compared with the corresponding experimental data. The validation results clearly illustrate the capability of the present two-phase FANS method for accurate prediction of impact pressure in sloshing LNG tank including violent free surface motion, three-dimensional instability and air trapping effects.

Ex-vessel Steam Explosion Analysis for Pressurized Water Reactor and Boiling Water Reactor

  • Leskovar, Matjaz;Ursic, Mitja
    • Nuclear Engineering and Technology
    • /
    • v.48 no.1
    • /
    • pp.72-86
    • /
    • 2016
  • A steam explosion may occur during a severe accident, when the molten core comes into contact with water. The pressurized water reactor and boiling water reactor ex-vessel steam explosion study, which was carried out with the multicomponent three-dimensional Eulerian fuel-coolant interaction code under the conditions of the Organisation for Economic Co-operation and Development (OECD) Steam Explosion Resolution for Nuclear Applications project reactor exercise, is presented and discussed. In reactor calculations, the largest uncertainties in the prediction of the steam explosion strength are expected to be caused by the large uncertainties related to the jet breakup. To obtain some insight into these uncertainties, premixing simulations were performed with both available jet breakup models, i.e., the global and the local models. The simulations revealed that weaker explosions are predicted by the local model, compared to the global model, due to the predicted smaller melt droplet size, resulting in increased melt solidification and increased void buildup, both reducing the explosion strength. Despite the lower active melt mass predicted for the pressurized water reactor case, pressure loads at the cavity walls are typically higher than that for the boiling water reactor case. This is because of the significantly larger boiling water reactor cavity, where the explosion pressure wave originating from the premixture in the center of the cavity has already been significantly weakened on reaching the distant cavity wall.

Unsteady Wet Steam Flow Measurements in a Low-Pressure Test Steam Turbine

  • Duan, Chongfei;Ishibashi, Koji;Senoo, Shigeki;Bosdas, Ilias;Mansour, Michel;Kalfas, Anestis I.;Abhari, Reza S.
    • International Journal of Fluid Machinery and Systems
    • /
    • v.9 no.1
    • /
    • pp.85-94
    • /
    • 2016
  • An experimental study is conducted for unsteady wet steam flow in a four-stage low-pressure test steam turbine. The measurements are carried out at outlets of the last two stages by using a newly developed fast response aerodynamic probe. This FRAP-HTH probe (Fast Response Aerodynamic Probe - High Temperature Heated) has a miniature high-power cartridge heater with an active control system to heat the probe tip, allowing it to be applied to wet steam measurements. The phase-locked average results obtained with a sampling frequency of 200 kHz clarify the flow characteristics, such as the blade wakes and secondary vortexes, downstream from the individual rotational blades in the wet steam environment.

A Study on Photoresist Stripping and Damage Using Atmospheric Pressure Plasma (대기압 플라즈마를 이용한 감광제 제거 공정과 damage에 관한 연구)

  • Hwang, In-Uk;Yang, Seung-Kook;Song, Ho-Young;Park, Se-Geun;O, Beom-Hoan;Lee, Seung-Gol;Lee, El-Hang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.152-155
    • /
    • 2003
  • Ashing of photoresist was investigated in dielectric barrier discharges in atmospheric pressure by changing applied voltage, frequency, flow rate. we analyzed the plasma by Optical Emission Spectroscopy(OES) to monitor the variation of active oxygen species. Another new peaks of oxygen radical is observed by addition of argon gas. This may explain the increase in ashing rate with argon addition. With the results of Optical Emission Spectroscopy(OES), we can find the optimized ashing conditions. MIS capacitor for monitoring charging damage by the plasma was also studied. The results suggest the dielectric barrier discharges(DBD) can be an efficient, alternative Plasma source for general surface processing.

  • PDF

Development of m-Health Application based on Medical Informatics Standards (의료정보 표준에 기반 한 m-Health 어플리케이션 개발)

  • Park, Hyun Sang;Kim, Hwa Sun;Jung, Hyun Jung;Cho, Hune
    • Journal of Korea Multimedia Society
    • /
    • v.17 no.5
    • /
    • pp.640-653
    • /
    • 2014
  • Recently medical consumers pursue high leveled quality of life through active promotion, prevention, management activity of health as the importance of health during home life is emerged to meet the aging society and chronic diseases. In addition, people are directed to the m-Health for managing yourself their health by using smartphone and various personal health devices, if necessary transmits health data to the physician himself. In the previous studies, m-Health Application were developed and applied in the real clinical environment by adopting the medical information standards was rarely conducted. Therefore, in this study, the m-Health application platform was developed. Developed application was communicate with IEEE 11073 standard protocol using the Bluetooth Health Device Profile in personal health device via smart phone to process blood pressure information, and it converted to HL7 V2.6 ORU_R01 message for send to remote medical server. In addition, we tested the interoperability and safety of the developed application for 23 inpatient and 17 outpatient at D University Hospital. As a result, the blood pressure information has been transmitted without error.

Extract of high hydrostatic pressure-treated danshen (Salvia miltiorrhiza) ameliorates atherosclerosis via autophagy induction

  • Ko, Minjeong;Oh, Goo Taeg;Park, Jiyong;Kwon, Ho Jeong
    • BMB Reports
    • /
    • v.53 no.12
    • /
    • pp.652-657
    • /
    • 2020
  • Danshen (Salvia miltiorrhiza) is a traditional medicinal plant widely used in Asian countries for its pharmacological activities (e.g., amelioration of cardiovascular diseases). In this study, we investigated the anti-atherosclerotic activity of raw danshen root extract prepared using high hydrostatic pressure (HHP) at 550 MPa for 5 min and hot water extraction. This method was useful for elimination of bacteria from cultured danshen plants and for better extraction yield of active principles. The HHP-treated danshen extract (HDE) inhibited proliferation of human umbilical vein endothelial cells (HUVECs) and induced autophagy that was assessed by LC3 conversion and p62 degradation. HDE suppressed foam cell formation in oxLDL-induced RAW264.7 macrophages; lysosomal activity simultaneously increased, measured by acridine orange staining. HDE also reduced atherosclerotic plaque development in vivo in apolipoprotein E knock-out (ApoE-/-) mice fed a high cholesterol diet. Taken together, these results indicated that HDE exhibited anti-atherosclerotic activity via autophagy induction.