• Title/Summary/Keyword: Flow diagnostics

Search Result 101, Processing Time 0.033 seconds

The understanding of Gwan-Gyeok in "Nangyeong" ("난경(難經)"의 관격(關格) 인식)

  • Jang, Woo-Chang
    • Journal of Korean Medical classics
    • /
    • v.24 no.6
    • /
    • pp.15-28
    • /
    • 2011
  • Gwan-Gyeok(關格) is one of the dangerous conditions that can lead to death and is considered important in clinical practice. However its true concept is unclear and arguments on the subject have been diverse over generations. This kind of confusion is largely due to an insufficient understanding of the study results on Nangyeong(難經). In Nangyeong, Gwan-Gyeok is divided into 'in bowels(在腑)' and 'in viscera(在臟) and distinction is made between 'damaged by heat(傷熱)' and 'damaged by dampness(傷濕) thus establishing a broad outline of differentiation of syndrome(辨證). Moreover, the clinical progress is systematically divided into 3 stages thus providing a very useful viewpoint on diagnostics. A sharp perspective on the pathogenesis is also shown by emphasizing the kidney and Myeongmun(命門) through the comparison between cheok pulse(尺) and chon pulse(寸). This point of view in Nangyeong is truly proposing a permanent standard on the understanding of Gwan-Gyeok. Therefore it is the author's hope that this study will work as a start to look back on the flow of the research on Gwan-Gyeok which has been rather confusing since Sanghallon(傷寒論).

Measurements of the Burning Velocities of Flamelets in a Turbulent Premixed Flame

  • Furukawa, Junichi;Noguchi, Yoshiki;Hirano, Toshisuke;Williams, Forman A.
    • Journal of the Korean Society of Combustion
    • /
    • v.7 no.2
    • /
    • pp.62-68
    • /
    • 2002
  • To investigate statistics of flamelet in a turbulent premixed flame and to obtain components of their burning velocities in a vertical plane above a pipe-flow burner, the local motion of flamelets with respect to gas are measured by specially arranged diagnostics, composed of an electrostatic probe with four identical sensors and a two-color four-beam LDV system. With this technique, the three-dimensional local flame- front-velocity vector is measured by the electrostatic probe for the first time, and simultaneously the axial and radial components of the local gas-velocity vector in a vertical plane above the vertically oriented burner are measured by the LDV system. Two components of burning velocities of planar flamelets can be obtained from these results and are found to be distributed over different directions and to range in magnitude from nearly zero to a few times the planar, un strained adiabatic laminar burning velocity measured in the unburnt gas. It may be concluded from these results that turbulence exerts measurable influences on flamelets and causes at least some of them to exhibit increased burning velocity.

  • PDF

Study on the Partially Premixed Flames Produced by a Coflow Burner as Temperature Calibration Source (동축류 버너에서 생성된 부분 예혼합 화염을 이용한 화염 온도 측정 검정원 연구)

  • Park, Chul-Woung;Hahn, Jae-Won;Shin, Hyun-Dong
    • Journal of the Korean Society of Combustion
    • /
    • v.5 no.1
    • /
    • pp.91-98
    • /
    • 2000
  • We investigated a uniform temperature zone, produced by double flame structure of a co flow CH4/air partially premixed flame, to be used as a temperature calibration source for laser diagnostics. A broadband N2 CARS(coherent anti-Stokes Raman spectroscopy) system with a modeless laser was used for temperature measurement. When the stoichiometric ratio was 1.5, we found the uniform temperature zone in radial direction of the flame of which the averaged temperature was 2110 K with standard deviation 24 K. In the stoichiometric ratio range between 2.0 and 2.5, we found very stable temperature-varying zones in vertical direction at the center of the flame. The size of the zone was approximately 15 mm and it covered a temperature range from 300 K to 1900 K. We also suggest that this zone can be used as a calibration source for 2-D PLIF(planar laser induced flurescence) temperature measurement.

  • PDF

Clinical evaluation of a rapid diagnostic test kit for detection of canine coronavirus

  • Yoon, Seung-Jae;Seo, Kyoung-Won;Song, Kun-Ho
    • Korean Journal of Veterinary Research
    • /
    • v.58 no.1
    • /
    • pp.27-31
    • /
    • 2018
  • Canine coronavirus is a single-stranded RNA virus that causes enteritis in dogs of any age. Coronaviral enteritis is seldom definitively diagnosed, since it is usually much less severe than many other types of enteritis and is self-limiting. Conventional diagnostics for the canine coronaviral enteritis such as polymerase chain reaction (PCR), virus isolation, and electron microscopic examination are inappropriate for small animal clinics due to the complicated experimental processes involved. Therefore, a commercially available lateral flow test kit based on chromatographic immunoassay techniques was tested to evaluate its performance as a first-line diagnostic test kit that could be used in clinics. The coronavirus antigen test kit detected canine coronavirus-infected dogs with 93.1% sensitivity and 97.5% specificity. The detection limit of the test kit was between $1.97{\times}10^4/mL$ and $9.85{\times}10^3/mL$ for samples with a 2-fold serial dilution from $1.25{\times}10^6\;TCID_{50}$ ($TCID_{50}$, 50% tissue culture infectious dose). Additionally, the test kit had no cross-reactivity with canine parvovirus, distemper virus, or Escherichia coli. Overall, the commercially available test kit showed good diagnostic performance in a clinical setting, with results similar to those from PCR, confirming their potential for convenient and accurate use in small animal clinics.

An Experimental Study on the Flow Characteristics and the Stratification Effects in Visualization Engine Using the DPIV and the Entropy Analysis (DPIV와 엔트로피 해석방법을 이용한 가시화 엔진내의 유동 특성 및 성층효과에 관한 실험적 연구)

  • Lee Changhee;Lee Kihyung;Lee Changsik
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.13 no.1
    • /
    • pp.9-18
    • /
    • 2005
  • The objective of this study is to analyse the spray characteristics according to the injection duration under the ambient pressure condition, and the injection timing in the visualization engine. In order to investigate the spray behavior, we obtained the spray velocity using the PIV method that has been an useful optical diagnostics technology, and calculated the vorticity from spray velocity component. These results elucidated the relationship between vorticity and entropy which play an important role in the diffusion process for the early injection case and the stratification process for the late injection case. In addition, we quantified the homogeneous diffusion rate of spray using the entropy analysis based on the Boltzmann's statistical thermodynamics. Using these method, it was found that the concentration of spray droplets caused by the increase of injection duration is more effective than the increase of momentum dissipation. We also found that the homogeneous diffusion rate increased as the injection timing moved to the early intake stroke process and BTDC $50^{\circ}$ was the most efficient injection timing for the stratified mixture formation during the compression stroke.

Study on self-pulsation characteristics of gas centered shear coaxial injector for supercavitating underwater propulsion system

  • Yoon, Jung-Soo;Chung, Jae-Mook;Yoon, Young-Bin
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.3 no.4
    • /
    • pp.286-292
    • /
    • 2011
  • In order to design a shear coaxial injector of solid particles for underwater propulsion system, basic experiments on gas-liquid shear coaxial injector are necessary. In the gas-liquid coaxial injector self-pulsation usually occurs with an intense scream. When self-pulsation occurs, mass flow rate oscillation and intense scream are detected by the interactions between the liquid and gas phase. Self-pulsation must be suppressed since this oscillation may cause combustion instabilities. Considerable research has been conducted on self-pulsation characteristics, but these researches are conducted in swirl coaxial injector. The main objective of this research is to understand the characteristics of self-pulsation in shear coaxial injector and reveal the mechanism of the phenomenon. Toward this object, self-pulsation frequency and spray patterns are measured by laser diagnostics and indirect photography. The self-pulsation characteristics of shear coaxial injector are studied with various injection conditions, such as the pressure drop of liquid and gas phase, and recess ratio. It was found that the frequency of the self-pulsation is proportional to the liquid and gas Reynolds number, and proportional to the L/d.

Investigation of Soot Formation in a D.I. Diesel Engine by Using Laser Induced Scattering and Laser Induced Incandescence

  • Lee, Ki-Hyung;Chung, Jae-Woo;Kim, Byung-Soo;Kim, Sang-Kwon
    • Journal of Mechanical Science and Technology
    • /
    • v.18 no.7
    • /
    • pp.1169-1176
    • /
    • 2004
  • Soot has a great effect on the formation of PM (Particulate Matter) in D.I. (Direct Injection) Diesel engines. Soot in diesel flame is formed by incomplete combustion when the fuel atomization and mixture formation were poor. Therefore, the understanding of soot formation in a D.I. diesel engine is mandatory to reduce PM in exhaust gas. To investigate soot formation in diesel combustion, various measurements have been performed with laser diagnostics. In this study, the relative soot diameter and the relative number density in a DJ. engine was measured by using LIS (Laser Induced Scattering) and LII (Laser Induced Incandescence) methods simultaneously which are planar imaging techniques. And a visualization D.I. diesel engine was used to introduce a laser beam into the combustion chamber and investigate the diffusion flame characteristics. To find the optimal condition that reduces soot formation in diesel combustion, various injection timing and the swirl flow in the cylinder using the SCV (Swirl Control Valve) were applied. From this experiment, the effects of injection timing and swirl on soot formation were established. Effective reduction of soot formation is possible through the control of these two factors.

A Study on the Soot Measurement in Laminar and Turbulent Diffusion Flame Using the Laser Diagnostics (광계측 기법을 이용한 층류 및 난류 확산 화염에서의 매연 측정에 관한 연구)

  • Lee, Jun-Yong;Han, Yong-Taik;Lim, Jun-Won;Min, Kyoung-Doug
    • Proceedings of the KSME Conference
    • /
    • 2008.11b
    • /
    • pp.3073-3078
    • /
    • 2008
  • In this study to find out the amount of soot, LII method, which utilizes a laser, was used in laminar diffusion flame and based upon the temperature and soot measured from the turbulent Diesel diffusion flame in the constant-volume chamber using the two-color method. Through these experiments, we could know that the LII signal is generally proportional to the soot amount in a laminar diffusion flame. And we could acquire the temperature and soot using the two-color method in a turbulent Diesel diffusion flame effectively. In addition to, this experiment revealed that the KL factor was high on parts of the chamber where the temperature dropped. On the other hand, the KL factor was low where the temperature increased rapidly. Also, it was possible to measure the highest temperature of a turbulent Diesel diffusion flame is approximately 2300K.

  • PDF

EXPERIMENTAL STUDY ON THE FLOW AND MIXTURE DISTIBUTION IN A VISUALIZATION ENGINE USING DIGITAL PARTICLE IMAGE VELOCIMETRY AND ENTROPY ANALYSIS

  • Lee, K.H.;Lee, C.H.
    • International Journal of Automotive Technology
    • /
    • v.8 no.2
    • /
    • pp.127-135
    • /
    • 2007
  • The objective of this study is to analyze the effect of velocity and vorticity on stratified mixture formation in the visualization engine. In order to investigate spray behavior, the pray velocity is obtained through the cross-correlation PIV method, a useful optical diagnostics technology and the vorticity calculated from the spray velocity component. These results elucidated the relationship between vorticity and entropy, which play an important role in the diffusion process for the early injection case and the stratification process for the late injection case. In addition, we quantified the homogeneous diffusion ate of spray using entropy analysis based on Boltzmann's statistical thermodynamics. Using these methods, we discovered that the homogeneous mixture distribution is more effective as a momentum dissipation of surrounding air than that of the spray concentration with a change in the injection timing. We found that the homogenous diffusion rate increased as the injection timing moved to the early intake stroke process, and BTDC $60^{\circ}$ was the most efficient injection timing for the stratified mixture formation during the compression stroke.

The Algorithm of Life Time Diagnostics end Evaluating of Exchanges Time about High Pressure Sodium Vapor Lamp Using the LabVIEW Software Package (LabVIEW 소프트웨어 패키지를 이용한 고압나트륨전등의 교환시점 및 수명진단 알고리듬)

  • Han, Tae-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.6
    • /
    • pp.1-7
    • /
    • 2004
  • It is necessary for starting voltage to him on high pressure discharge lamp. This starting voltage supply to high pressure sodium vapor lamp as electric discharge lamp, Electric field is producted in Electric discharge tube, So accelerative electron collide against vapour atom and second electron is generated, And rapidly the current flow to Electric discharge tube. This paper showed that the life cycle and exchanges time for all electric discharge lamp was different according to each manufactures, This paper is proposed the evaluating algorithm of exchanges time for high pressure sodium vapor lamp, used LabVIEW software package.