• The Korean Journal of Pharmacology
• /
• v.15 no.1_2 s.25
• /
• pp.1-5
• /
• 1979

Previous studies concerning the usefulness of pleural fluid glucose levels in differentiating causes of pleural effusions have been conflicting. Gelenger and Wiggers (1949), Calnan et al(1951) and Barber et al(1957) concluded that the lower the level of pleural fluid glucose, the more likely was tuberculosis, and that tuberculosis was unlikely if the pleural fluid glucose level was more than 80 mg/100 ml. Light and Ball(1973), however, reported that in the great majority of tuberculous pleural fluids the glucose concentration was high rather than low, concluded that the pleural fluid glucose levels were not useful in the differential diagnosis of pleural effusion. In this study, pleural fluid glucose was determined in 46 pleural effusions from various causes to evaluate the usefulness in the differential diagnosis of pleural effusion. In addition, the protein concentration and the electrophoretic patterns of protein and amylases in pleural fluid was compared with that of serum. And the results were as follows. 1. The mean glucose concentration of pleural fluid was 80.8 mg/100 ml in 22 tuberculous origin, 92.5 mg/100 ml in 12 cancer patient and 70.4 mg/100 ml in 10 undiagnosed cases. In 2 cases of paragonimiasis the pleural fliud glucose levels were low (mean, 32.0 mg/100 ml). The percentage of pleural fluid protein to serum is about 75% in all disease groups and the protein level of tuberculous pleural fluid was significantly correlated with that of serum. 2. The disc eletrophoretic patterns of pleural fluid were almost similar with that of serum in all disease groups but the prealbumin fraction was not observed in pleural fluid. 3. With the isoelectric focusing, 4 to 7 isoamylase was observed in serum and the isoelectric point was ranged from pH 5.8 to 7.8 and isoelectic point of main fracticn is pH 7.2. The isoelectic focusing patterns of amylase of pleural fluid were identical to that of serum in all disease group. With the above results it is concluded that the pleural fluid is exudate of serum and that the glucose levels of pleural fluid are not useful in the differential diagnosis of pieural effusions.

• Korean Journal of Adult Nursing
• /
• v.25 no.5
• /
• pp.567-573
• /
• 2013

Purpose: The purpose of this study was to compared two methods for measuring fluid intake and to assess the most effective method. Methods: Data from 44 hospitalized patients with chronic kidney disease was analyzed. Two methods were used. The liquid method is to measure the daily intake of water in the form of pure water or some other beverage and IV fluid, the liquid-solid method is to measure the daily intake of water which enters by the oral route and IV fluid. Results: The daily intake of fluid was 1483.10mL and 2245.99mL respectively. The fluid output was 1883.72 mL. The Intra-Class Correlation (ICC) between the liquid method and the liquid-solid method and fluid output was 0.64 and 0.69, respectively. The correlation between differences of fluid in two methods and body weight change was r=.47 (p<.001) and r=.56 (p<.001), respectively. Conclusion: The results of this study suggest that there are no difference between the two measuring methods as to reflecting the most close value to fluid output. And the difference between intake and output by two methods is correlated with body weight change. Therefore, it can be suggested that the either method could be useful as patients' fluid intake measurement.

• Korean Journal of Veterinary Research
• /
• v.43 no.2
• /
• pp.263-270
• /
• 2003

The objective of the present study was to investigate the use of fluid released from muscle samples as an alternative to serum for ELISA to detect classical swine fever(CSF) virus antibodies in slaughter pigs. The optimal correspondence between serum 1:20 OD values and muscle fluid OD values was achieved at a muscle fluid dilution of 1:2. Significant correlation was found between serum and neck muscle ELISA ($r_s=0.880$, p<0.0001, ${\kappa}=0.82$; specificity of 97.0% and sensitivity 90.6%). The semimembranous muscle showed similar correlation in CSF ELISA($r_s=0.877$, p<0.0001, ${\kappa}=0.75$; specificity of 94.1% and sensitivity 89.1%). High correlation was obtained between serum and mesenteric lymph node in the CSF ELISA ($r_s=0.937$, p<0.0001, ${\kappa}=0.87$; specificity of 97.1% and sensitivity 93.0%). Measmement agreement between serum ELISA and muscle fluid ELISA was calculated and expressed as limits of agreement. The correspondence of ELISA of serum and muscle fluid indicated limits of agreement. Above 95% of all muscle fluid values were distributed within this limits of agreement. Among the samples used for ELISA for detecting CSFV antibodies, mesenteric lymph node had the most correlation and agreement with serum ELISA. F-test for comparison of variances showed no significant difference between the serum and muscle fluid. In conclusion, muscle fluid is a useful postmortem alternative to serum to detect CSFV antibodies.

• 한국전산유체공학회:학술대회논문집
• /
• 2009.11a
• /
• pp.1-1
• /
• 2009

In this presentation, I talk about various fluid simulation methods that have been developed for computer graphics special effects since 1996. They are all based on CFD but sacrifice physical reality for visual plausability and time. But as the speed of computer increases rapidly and the capability of GPU (graphics processing unit) improves, methods for more physical realism have been tried. In this talk, I will focus on four aspects of fluid simulation methods for computer graphics: (1) particle level-set methods, (2) particle-based simulation, (3) methods for exact satisfaction of incompressibility constraint, and (4) GPU-based simulation. (1) Particle level-set methods evolve the surface of fluid by means of the zero-level set and a band of massless marker particles on both sides of it. The evolution of the zero-level set captures the surface in an approximate manner and the evolution of marker particles captures the fine details of the surface, and the zero-level set is modified based on the particle positions in each step of evolution. (2) Recently the particle-based Lagrangian approach to fluid simulation gains some popularity, because it automatically respects mass conservation and the difficulty of tracking the surface geometry has been somewhat addressed. (3) Until recently fluid simulation algorithm was dominated by approximate fractional step methods. They split the Navier-Stoke equation into two, so that the first one solves the equation without considering the incompressibility constraint and the second finds the pressure which satisfies the constraint. In this approach, the first step introduces error inevitably, producing numerical diffusion in solution. But recently exact fractional step methods without error have been developed by fluid mechanics scholars), and another method was introduced which satisfies the incompressibility constraint by formulating fluid in terms of vorticity field rather than velocity field (by computer graphics scholars). (4) Finally, I want to mention GPU implementation of fluid simulation, which takes advantage of the fact that discrete fluid equations can be solved in parallel.

• Journal of Power System Engineering
• /
• v.15 no.1
• /
• pp.24-31
• /
• 2011

Rectangular box type structures are used in many fields of civil, mechanical and marine engineering. Especially, Most ship structures are often in contact with inner or outer fluid, like ballast, fuel and stem tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine and propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tanks. Many authors have studied vibration of rectangular tanks containing fluid. Few research on dynamic interaction among tank walls filled with fluid are reported in the vibration of rectangular tanks recently. In case of rectangular tanks, structural coupling between adjacent panels and effect of vibration modes of multiple panels on added mass of water have to be considered. In the previous report, a numerical analysis is performed for the coupling effect between panels of a tank on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region, and mode characteristics in accordance with changing breadth of the plates by using finite element method for plates and boundary element method for fluid region. In this paper, the coupling effect between panels of a tank on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region, and mode characteristics in accordance with changing length, thickness, and boundary condition of the plates are investigated numerically and discussed.

• Journal of Korean Society of Transportation
• /
• v.27 no.1
• /
• pp.27-34
• /
• 2009

The operational effect of traffic signal control improvement was evaluated using the Two-Fluid Model. The parameters engaged in the Two-Fluid Model becomes food indicators to measure the quality of traffic flow due to the improvement of traffic signal operation. A series of experiment were conduced for the 31 signalized intersections in Uijeongbu City. To estimate the parameters in the Two-Fluid Model the trajectory informations of individual vehicles were collected using the CORSIM and Run Time Extension. The test results showed 35 percent decrease of average minimum trip time per unit distance. One of the parameters in the Two-Fluid Model is a measure of the resistance of the network to the degraded operation with the increased demand. The test result showed 28 percent decrease of this parameter. In spite of the simulation results of the arterial flow, it was concluded that the Two-Fluid Model is useful tool to evaluate the improvement of the traffic signal control system from the macroscopic aspect.

• International Journal of Fluid Machinery and Systems
• /
• v.3 no.4
• /
• pp.342-351
• /
• 2010

During the operation of a hydro turbine the fluid mechanical pressure loading on the turbine blades provides the driving torque on the turbine shaft. This fluid loading results in a structural load on the component which in turn causes the turbine blade to deflect. Classically, these mechanical stresses and deflections are calculated by means of finite element analysis (FEA) which applies the pressure distribution on the blade surface calculated by computational fluid dynamics (CFD) as a major boundary condition. Such an approach can be seen as a one-way coupled simulation of the fluid structure interaction (FSI) problem. In this analysis the reverse influence of the deformation on the fluid is generally neglected. Especially in axial machines the blade deformation can result in a significant impact on the turbine performance. The present paper analyzes this influence by means of fully two-way coupled FSI simulations of a propeller turbine utilizing two different approaches. The configuration has been simulated by coupling the two commercial solvers ANSYS CFX for the fluid mechanical simulation with ANSYS Classic for the structure mechanical simulation. A detailed comparison of the results for various blade stiffness by means of changing Young's Modulus are presented. The influence of the blade deformation on the runner discharge and performance will be discussed and shows for the configuration investigated no significant influence under normal structural conditions. This study also highlights that a two-way coupled fluid structure interaction simulation of a real engineering configuration is still a challenging task for today's commercially available simulation tools.

• Journal of the Korea Institute of Building Construction
• /
• v.3 no.4
• /
• pp.79-86
• /
• 2003

The purpose of study is to offer base data for high fluid concrete mix property, as grasp effect of aggregate to reach much more effect for producing high fluid concrete. For this study, there are three types of combined aggregates, river sand + river aggregate(type A), river sand + crusted aggregate(type B), washed sea sand + crushed aggregate(type C) and take a factor, water-contents, water-binder ratio and S/a. And so, we had following conclusion, resulting application-ability of high fluid mortar by K-slump tester to use a handy consistency measuring instrument. And so, we had following conclusion, resulting application-ability of high fluid concrete by K-slump tester to use a handy consistency measuring instrument. 1) In cafe of regular water binder ratio, high fluid concrete suffered much effect of combined aggregates and water binder ratio. Range of water binder ratio by combined aggregates is w/b 0.4 downward(type A and B), w/b 0.35 downward(type C). 2) Water contents to need for producing high fluid concrete is minimum 170kg/$\textrm{m}^3$ without regard to combined aggregates. 3) The effect of S/a on high fluid concrete by combined aggregates is approximately S/a 50% (type A and B), s/a 50-55% (type C). 4) Consistency measuring of high fluid concrete by K-slump tester is possible and first indication value, high fluid concrete can be produced, is 6~10.5cm.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.2
• /
• pp.318-327
• /
• 2002

In this paper, heat transfer and pressure oscillation characteristics on oscillating capillary tube heat pipe(OCHP) according to input heat flux, mixture ratio of working fluid and inclination angle were investigated and were compared single working fluid(R-142b) with binary mixture working fluid(R-142b-Ethano1). OCHP was made to serpentine structure of loop type with 10 turns by drilling the channels of length 220mm, width 1.5mm, and depth 1.5mm on the surface of brass plate. In this study, R-l42b and R-l42b-Ethanol were used as working fluids, the charging ratio of working fluids was 40(vol.%), the input heat flux to evaporating section was changed from 0.3W/㎠ to 1.8W/㎠, and mixture ratio of working fluid was R(100%), R(95%)-E(5%), R(90%)-E(10%), and R(85%)-E(15%). From the experimental results, it was found that the effective thermal conductivity of single working fluid was better than that of binary mixture working fluid. But, in case of binary mixture working fluid, critical heat flux was higher than that of single working fluid. And, the higher the mixture ratios of working fluid, the lower heat transfer performance. In case of pressure oscillation, as the inclination angle was lower, pressure wave was more irregular. These phenomena were more serious when the working fluid was binary mixture. Besides, when mixture ratio was higher, saturated pressure was increased, more irregular wave was observed and the mean amplitude was increased. For the same input heat flux, inclination angle and charging ratio, when pressure oscillation has sinusoidal wave, mean amplitude was small, and saturated pressure was low value, the heat transfer was excellent.

• Coupled systems mechanics
• /
• v.7 no.6
• /
• pp.649-668
• /
• 2018

In this paper, we present a numerical model for fluid-structure interaction between structure built of porous media and acoustic fluid, which provides both pore pressure inside porous media and hydrodynamic pressures and hydrodynamic forces exerted on the upstream face of the structure in an unified manner and simplifies fluid-structure interaction problems. The first original feature of the proposed model concerns the structure built of saturated porous medium whose response is obtained with coupled discrete beam lattice model, which is based on Voronoi cell representation with cohesive links as linear elastic Timoshenko beam finite elements. The motion of the pore fluid is governed by Darcy's law, and the coupling between the solid phase and the pore fluid is introduced in the model through Biot's porous media theory. The pore pressure field is discretized with CST (Constant Strain Triangle) finite elements, which coincide with Delaunay triangles. By exploiting Hammer quadrature rule for numerical integration on CST elements, and duality property between Voronoi diagram and Delaunay triangulation, the numerical implementation of the coupling results with an additional pore pressure degree of freedom placed at each node of a Timoshenko beam finite element. The second original point of the model concerns the motion of the outside fluid which is modeled with mixed displacement/pressure based formulation. The chosen finite element representations of the structure response and the outside fluid motion ensures for the structure and fluid finite elements to be connected directly at the common nodes at the fluid-structure interface, because they share both the displacement and the pressure degrees of freedom. Numerical simulations presented in this paper show an excellent agreement between the numerically obtained results and the analytical solutions.