• Title/Summary/Keyword: Fluid Surface

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Prints as Avant-garde Language of Mass Culture (대중문화의 전위 언어로서 프린트)

  • Yim, Young-Kil;Kim, Sook-Young
    • The Journal of the Korea Contents Association
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    • v.9 no.2
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    • pp.181-192
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    • 2009
  • Prints in the contemporary art has the radical aspects at not only to maintain the characteristic of printmaking in a field of visual image but also to fulfill and communicate a desire of the public. We can see this from the change of the printmaking forms among the alternation of diverse expression methods and media such as from the line-cut at the Renaissance to colored print process, photography, the beginning of 20th century cartoons, advertisement, art, and graphic poster. From that, we can understand the printmaking as a fluid media, not fixed, has finely accomplished its functions as an act of visual language to smoothly communicate with the individual desire and character than word or language at the complex and various cultural surface. This study is focused on that prints as an avant-garde language in popular culture. Therefore, I have examined the following two aspects. First, with focussing at the specific characters of the graphic posters, I try to define the differences between language and visual language and the effect from it to our emotional perception and behavior with the politic and economic point of view. Second, how has the printmaking art as an fine arts finely accomplished an linguistic action. These are the purpose of this study.

Altered Cerebral Vasomotion with Decreased CGRP Level in Pial Arteries of Spontaneously Hypertensive Rats

  • Lee, Kwang-Ho;Choi, Jae-Moon;Hong, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.5
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    • pp.573-580
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    • 1998
  • The study aims to identify the mechanism (s) underlying the altered vasodilatory responses of the pial artery of spontaneously hypertensive rats (SHR) under a hypothesis that calcitonin gene-related peptide (CGRP) exerts a modulator role in the autoregulation of cerebral blood flow (CBF). The animals were divided into four groups: 1) Sprague-Dawley rats (SDR), 2) Wistar rats (WR), 3) SHR with high blood pressure $(BP{\ge}150\;mmHg),$ and 4) SHR with normotensive BP $({\le}150\;mmHg).$ The lower limit of CBF autoregulation in SHR shifted to a higher BP $(82.8{\pm}9.3\'mmHg,\;P<0.05)$ than that in SDR $(58.9{\pm}5.7\;mmHg)$. In SHR, whether the BP levels were high or normotensive, the vasodilator responses to a stepwise hypotension were significantly attenuated unlike with SDR and WR. When artificial cerebrospinal fluid (CSF) containing capsaicin $(3{\times}10^{-7}\;M)$ was suffused over the cortical surface, a transient increase in pial arterial diameter was observed in the SHR with high or normotensive BP. In contrast, SDR and WR showed a large increase in diameter, and the increase was sustained for over 10 minutes. In line with these results, the basal releases of CGRP-like immunoreactivity (CGRP-LI) in the isolated pial arteries from SHR with high and normotensive BP were $12.5{\pm}1.4\;and\;9.8{\pm}2.8\;fmole/mm^2/60\;min\;(P<0.05)$, while those from SDR and WR were $25.5{\pm}3.1\;and\;24.6{\pm}3.1\;fmole/mm^2/60\;min,$ respectively. The isolated basilar arteries showed similar results to those of the pial arteries in SHR. Thus, it is summarized that, in the SHR, the reduced autoregulatory vasodilator responses to stepwise hypotension and capsaicin may be, in part, ascribed to the decreased release of CGRP from the perivascular sensory nerve fibers of the pial arteries, and that altered vasomotor activity in SHR may not be related with the hypertensive tone.

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A Suggested Method for Predicting Permeability of Porous Sandstone Using Porosity and Drying Rate (공극률과 건조율을 이용한 다공질 사암의 투과도 추정방법 제안)

  • Ko, Eunji;Kim, Jinhoo
    • Geophysics and Geophysical Exploration
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    • v.17 no.3
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    • pp.121-128
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    • 2014
  • As the permeability is an important parameter to characterize the ease with which a porous medium transmits fluids, it is usually obtained by fluid flow experiment using core samples. In order to measure the permeability, however, an experimental apparatus is required and it might take long measurement time, especially for tight samples. In this study, the relationship between permeability and porosity as well as drying rate has been investigated to predict the permeability without a series of measuring experiments. Porosity is measured by drying monitoring method, which measures weight variation continuously while drying surface-dried saturated sample, and drying rate is obtained from weight variation ratio with respect to the water saturation. The total of 6 Berea sandstone samples, which have a permeability range of 70 to 670 mD, were used in this work, and a new and empirical equation which could predict permeability of porous sandstone by using porosity and drying rate were obtained through regression analysis.

TPH Removal of Oil-Contaminated Soil by Hot Air Sparging Process (고온 공기분사공정에 의한 유류오염대수층의 TPH 제거)

  • Lee, Jun-Ho;Park, Kap-Song
    • Journal of Korean Society on Water Environment
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    • v.23 no.5
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    • pp.665-675
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    • 2007
  • In-situ Air Sparging (IAS, AS) is a remediation technique in which organic contaminants are volatilized from saturated zone to unsaturated layer. This study focuses on the removal and interaction of Volatile Organic Compounds (VOCs) and $CO_2$, and Total Petroleum Hydrocarbon (TPH) in saturated and unsaturated, and air space zone on the unsaturated soil surface. Soil sparging temperature of hot air has risen to $34.9{\pm}2.7^{\circ}C$ from $23.0{\pm}1.9^{\circ}C$ for 36 days. At the diffusing point, fluid TPH concentrations were reduced to 78.7% of the initial concentration in saturated zone when hot air was sparged. The TPH concentrations were decreased to 66.1% for room temperature air sparging. The amount of VOCs for hot air sparging system, in air space, was approximately 26% larger than constant air sparging system. The amount of $CO_2$ was 4,555 mg (in unsaturated zone) and 4,419 mg (in air space) when hot air was sparged was 3,015 mg (in unsaturated zone) and 3,634 mg (in air space) for room air temperature in the $CO_2$ amount. The removals of VOCs and biodegradable $CO_2$ through the hot air sparging system (modified SVE) were more effective than the room temperature air sparging. The regression equation were $Y=976.4e^{-0.015{\cdot}X}$, $R^2=0.98$ (hot air sparging) and $Y=1055e^{-0.028{\cdot}X}$, $R^2=0.90$ (room temperaure air sparging). Estimated remediation time was approximately 500 days, if final saturated soil TPH concentration was set to 1.2 mg/L application of tail effect.

Computation of Flowfield and Infrared Signature in Aircraft Exhaust System for IR Reduction Design (항공기 후방동체 열유동장 및 IR 신호 예측 시스템)

  • Moon, Hyuk;Yang, Young-Rok;Chun, Soo-Hwan;Choi, Seong-Man;Myong, Rho-Shin;Cho, Tae-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.7
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    • pp.652-659
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    • 2011
  • A computational system to predict flowfield and infrared signature in aircraft exhaust system is developed. As the first step, a virtual mission profile is considered and an engine is selected through a performance analysis. Then a nozzle that meets the requirement of each mission is designed. The internal flow in the exhaustion nozzle at the maximum thrust is analyzed using a state-of-the-art CFD code. In addition, a system to combine information of the skin temperature distribution of the nozzle and after-body surface with an infrared prediction code is developed. Finally, qualitative results for the infrared signature reduction design are obtained by investigating the infrared signature level under various conditions.

The Effect of Hyaluronan Treatment in Endotoxemic Rats

  • Rho, Byung-Hak;Kwon, Kun-Young;Choi, Won-Il
    • Tuberculosis and Respiratory Diseases
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    • v.70 no.5
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    • pp.390-396
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    • 2011
  • Background: Hyaluronan (HA) is an unbranched glycosaminoglycan. It has been proposed that HA acts as a vehicle for cytokines due to the strong negative charge on its surface. We hypothesized that HA would function like a cytokine scavenger and reduce the inflammatory signaling cascade and this would lead to improved survival in rats suffering with endotoxemia. Methods: Endotoxin (Salmonella, 10 mg/kg) or an equal amount of 0.9% NaCl (NS) was injected into the jugular vein of rats. HA (1,600 kDa, 0.35%) or NS was given at 0.1 mL/kg/h for 3 hours. HA or NS infusion was started at 4 hour after endotoxin injection. The rats were divided into the control and HA groups (n=16 for each group). The mean arterial pressure (MAP) was monitored during HA or normal saline infusion. Survival was assessed every 12 hours for 3 days throughout the experiment. Results: The survival rate (%) of the rats treated with HA was higher (60%) than that of the controls (20%) when HA was infused 4 hours after lipopolysaccharide (LPS) injection. The bronchoalveolar lavage (BAL) fluid of the animals surviving HA or NS infusion 4 hours after LPS showed that the total cell counts and number of neutrophils were significantly (p < 0.01) reduced in the HA treated groups compared with that of the controls (total cell count, $9.2{\times}10^4$/mL vs. $61{\times}10^4$/mL; neutrophils, $21{\times}10^4$/mL vs. $0.2{\times}10^4$/mL, respectively). There was no significant MAP difference between the HA or control groups either with or without endotoxin. Conclusion: Infusion of hyaluronan (1,600 kDa) reduced the BAL total cell count and the number of neutrophils and it improved the survival rate of the endotoxemic rats.

A Conservative USCIP Simulation Method for Shallow Water (물 표면 시뮬레이션을 위한 보존적 USCIP법)

  • Jeon, Sejong;Song, Oh-young
    • Journal of the Korea Computer Graphics Society
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    • v.25 no.5
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    • pp.21-30
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    • 2019
  • We propose a physical simulation method based on the shallow water equation(SWE) to represent water surface effectively. In this paper, the water which can be represented has a much larger width compared to the depth does not have a large vertical direction flow. In order to calculate the water flow efficiently, we start with the shallow water equation as the governing equation, which is a simplified version of the Navier-Stokes equation. In order to numerically calculate the advection term of the SWE, we introduce a new conservtive USCIP(CUSCIP) method which improves the Constrained Interpolation Profile (CIP) method to preserve the physical quantity while increasing the numerical accuracy. The proposed method is based on Kim et. al.'s Unsplit Semi-lagrangian CIP[9], and calculates advection term with additional constraints on term that consider integral values. The experimental results show that the CUSCIP method is robust to the loss of physical quantity due to numerical dissipation, which improves wave detail and persistence.

Experimental and Numerical Study on Slamming Impact

  • Kwon, Sun Hong;Yang, Young Jun;Lee, Hee Sung
    • Journal of Ocean Engineering and Technology
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    • v.27 no.1
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    • pp.1-8
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    • 2013
  • This paper presents the results of experimental and numerical research on the slamming phenomenon. Two experimental techniques were proposed in this study. The traditional free drop tests were carried out. However, the free drop tests done in this study using an LM guide showed excellent repeatability, unlike those of other researchers. The coefficients of variation for the drop test done in this experiment were less than 0.1. The other experimental technique proposed in this study was a novel concept that used a pneumatic cylinder. The pneumatic cylinder could accelerate the specimen over a very short distance from the free surface. As a result, high rates of repeatability were achieved. In the numerical study, the development of in-house code and utilization of commercial code were carried out. The in-house code developed was based on the boundary element method. It is a potential code. This was mostly applied to the computation of the wedge entry problem. The commercial code utilized was FLUENT. Most of the previous slamming research was done under the assumption of a constant body velocity all through the impact process, which is not realistic at all. However, the interaction of a fluid and body were taken into account by employing a user-defined function in this study. The experimental and numerical results were compared. The in-house code based on BEM showed better agreement than that of the FLUENT computation when it cames to the wedge computation. However, the FLUENT proved that it could deal with a very complex geometry while BEM could not. The proposed experimental and numerical procedures were shown to be very promising tools for dealing with slamming problems.

Analysis of Terminal Velocity, Drag Coefficient and Shape of Bubble Rising in High Viscous Fluid (고점도 유체 내에서 부양하는 거품의 종말속도, 항력계수, 형태 분석)

  • Kim, Jin Hyun;Kim, Jung Hyeun
    • Korean Chemical Engineering Research
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    • v.48 no.4
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    • pp.462-469
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    • 2010
  • Gas-liquid 2 phase processes are usually used in chemical, biochemical, environmental engineering and food process. For optimizing these processes, understanding bubble's precise movement and shape are needed. Bubble's movement and shape are effected by liquid's properties-viscosity, surface tension and bubble's properties-size, velocity. This paper deals with experimental data of bubble's movement and shape in high viscous silicone oil. Also, drag coefficient and deformation factor given by other researcher's papers and books are used to predicting and comparing bubble's terminal velocity, drag coefficient, deformation factor and shape with experimental value. Experimental data show that bubble moves faster when it moves in lower viscous silicone oil and it's drag coefficient is bigger when it moves in high viscous silicone oil. Bubble's shape is close to sphere when moving in high viscous silicone. Formulas proposed by Batchelor expect most accurate prediction for bubble's velocity and drag coefficient. Bubble's 2D shape predicted by Batchelor's energy balance, drag coefficient and deformation factor show excellent agreement with experimental bubble's 2D shape.

Over Time Stability of Ear Acupuncture Needle in the Body Fluid (이침(耳鍼)의 시술 기간에 따른 체액 내 부식 안전성 연구)

  • Lee, Sang-Hun;Lee, Sae-Bhom;Choi, Gwang-Ho;Choi, Sun-Mi;Ryu, Yeon-Hee
    • Journal of Acupuncture Research
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    • v.28 no.5
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    • pp.97-102
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    • 2011
  • Meridian Research Center, Division of Standard Research, Keora Institute of Oriental Medicine Objectives : Ear acupuncture needle is used to treat smoking, drug abusing, alcoholism frequently over time stability of ear acupuncture needle is important factor for safe acupuncture treatment. In spite of the importance, there has been few study about the quality of disposable acupuncture needle tip - using scanning electron microscope (SEM) in 2002, 2003. Moreover, there was no study about ear acupuncture needle. Methods : The three ear acupuncture needle, made in China, Japan, Korea was chosen. We used Hank's solution at the 38$^{\circ}C$ as a phantom tissue liquid. Except for the control group, five groups of needles are soused one to five days. Surface corrosion was observed using the SEM compared with control group. Results : There was no particular corrosion in all groups of ear acupuncture needles compared with the control group. Conclusions : All of the ear acupunctures used in this study are stable in body fluids at least 5 days.