• Title/Summary/Keyword: Fluid-fluid level

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Cerebrospinal fluid flow in normal beagle dogs analyzed using magnetic resonance imaging

  • Cho, Hyunju;Kim, Yejin;Hong, Saebyel;Choi, Hojung
    • Journal of Veterinary Science
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    • v.22 no.1
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    • pp.2.1-2.10
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    • 2021
  • Background: Diseases related to cerebrospinal fluid flow, such as hydrocephalus, syringomyelia, and Chiari malformation, are often found in small dogs. Although studies in human medicine have revealed a correlation with cerebrospinal fluid flow in these diseases by magnetic resonance imaging, there is little information and no standard data for normal dogs. Objectives: The purpose of this study was to obtain cerebrospinal fluid flow velocity data from the cerebral aqueduct and subarachnoid space at the foramen magnum in healthy beagle dogs. Methods: Six healthy beagle dogs were used in this experimental study. The dogs underwent phase-contrast and time-spatial labeling inversion pulse magnetic resonance imaging. Flow rate variations in the cerebrospinal fluid were observed using sagittal time-spatial labeling inversion pulse images. The pattern and velocity of cerebrospinal fluid flow were assessed using phase-contrast magnetic resonance imaging within the subarachnoid space at the foramen magnum level and the cerebral aqueduct. Results: In the ventral aspect of the subarachnoid space and cerebral aqueduct, the cerebrospinal fluid was characterized by a bidirectional flow throughout the cardiac cycle. The mean ± SD peak velocities through the ventral and dorsal aspects of the subarachnoid space and the cerebral aqueduct were 1.39 ± 0.13, 0.32 ± 0.12, and 0.76 ± 0.43 cm/s, respectively. Conclusions: Noninvasive visualization of cerebrospinal fluid flow movement with magnetic resonance imaging was feasible, and a reference dataset of cerebrospinal fluid flow peak velocities was obtained through the cervical subarachnoid space and cerebral aqueduct in healthy dogs.

A Study on the Radiated Noise the Prediction in the Pipe by Fluid Induced Vibration using the Radiation Efficiency and Pipe Surface Vibration (배관 표면진동과 방사효율을 이용한 배관 소음예측기법 연구)

  • Yi, Jongju;Park, Kyunghoon;Jung, Woojin;Seo, Youngsoo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.10
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    • pp.763-769
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    • 2014
  • This study is on the experiment and prediction of the pipe noise due to the internal fluid. The vibration of pipe external surface and noise in air were measured according to the internal fluid velocity and pipe type. In the experiment, the vibration and noise level of the straight pipe and rounded pipes show that the vibration and noise level are almost same. The 900 mitred pipe shows the high vibration and noise level. In the prediction of noise due to the internal flow, the method using the pipe surface vibration and radiation efficiency shows good agreement with experimental result.

Fluid Flow Analysis of the Threshold based Leaky Bucket Scheme

  • Park, Chul-Geun
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.274-279
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    • 1998
  • We investigate a Leaky Bucket(LB) scheme with a threshold in the data buffer, where leaky rate changes depending on the contents of data buffer. We use the fluid flow model for the analysis of the LB scheme with a threshold. We model the bursty input source as markov modulated fluid flow(MMFF) As performance measures we obtain loss probability and mean delay. We present some numerical results to show the effects of the level of a threshold, the rate of token generation, the size of token pool, and the size the data buffer on the performances of the LB scheme with a threshold.

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Tracking of Evolving Solid-Fluid Interface Using Level set and MLS-based finite elements with variable nodes (MLS기반 변절점 유한요소 및 레벨셋 방법을 이용한 고체-유체 경계의 전산모사)

  • Lim, Jae-Hyuk;Cho, Young-Sam;Im, Se-Young
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.416-418
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    • 2004
  • Tracking of evolving solid-fluid interfaces is treated using level set method and MLS-based finite element with variable nodes. Several applications will be illustrated to demonstrate the effectiveness of the present scheme

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Studies on Effective Fluid Monitoring Terminal design with the Use of location-based service (위치기반서비스를 활용한 효율적인 수액 모니터링 단말기 디자인에 관한 연구)

  • Lee, Hyo-Seung;Oh, Jae-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.4
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    • pp.421-426
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    • 2016
  • Fluid is normally used so that certain drug can be administered to patients for certain period of time. There are many incidents in which patients or guardians need to call upon medical staff after estimating the time of fluid injection termination. In case fluid injection is terminated during certain period such as sleeping time or others, it may cause more fatigue for either patients or guardians. Also, it may lead to ineffective work as medical staff needs to monitor the quantity of fluid several times in order to check the time of fluid injection termination. Therefore, the purpose of this study is to propose LBS system combined of minimum equipment and active RFID to monitor the level of fluid in order to solve abovementioned problems. Also, it is expected to enhance the quality of medical service with service in which real-time monitoring of fluid quantity and patient location is conducted to provide accurate information to either patients, guardians, or medical staff(nurse) so that medical staff can locate and see patients at the time of fluid injection termination.

Dynamic Characteristics of Magneto-rheological Fluid Actuator for Micro-motion Control (미세동작제어를 위한 자기유변유체 구동기의 동적 특성)

  • Kim, Pyunghwa;Han, Chulhee;Suresh, Kaluvan;Park, Choon-Yong;Shin, Cheol-Soo;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.5
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    • pp.511-517
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    • 2016
  • This paper presents dynamic characteristics of a new actuator using magneto-rheological(MR) fluid between two electrode type coils. The concept of the actuator is to strengthen the force due to the magnetic field produced by the electrode-coil for MR fluid. The amount and direction of current input to the electrode-coils decide the characteristics of contraction-mode and extension-mode. For achieving the required actuating displacement and actuating force, the yield stress of the MR fluid between two electrode-coils is precisely changed by the input current. In this work, the MR fluid is operated in squeeze mode. The experimental results shown in this paper depict that it can be applied in the micro-level displacement and vibration control system.

Analysis of Heat Transfer of a Magnetic Fluid Seal (자성유체씰의 열전달 해석)

  • Kim, Ock-Hyun;Lee, Hee-Bok;Lee, Min-Ki;Hong, Jeong-Hui;Kwak, Yong-Woon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.3
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    • pp.365-369
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    • 2010
  • Magnetic fluid seal is characterized by its simple design, low friction and being dustless. Those advantages are deduced from the fact that the sealing element is not a solid such as rubber or plastic but it is a fluid. Those are critical for application to a rotating shaft which is inserted into a vacuum chamber where high level of vacuum and cleanness are required. For the reason the magnetic fluid seal has become a standard for vacuum chambers for semiconductor and LCD processing. It should be noted that its sealing performance is sensitive to temperature. If necessary, water cooling should be considered. Thus anticipation of the temperature distribution of the magnetic fluid seal is important before applying it. In this paper an FEM analysis of the heat transfer has been executed and compared with experimental results. An overall convective heat transfer coefficient has been adopted for the analysis, which results in satisfactory consistency of the theoretical and experimental results.

A Study on the Imfluence of the Pipe Line of Boiler for Flame Distribution of Combustion Furnace (연소로의 화염분포가 보일러 관로에 미치는 영향에 관한 연구)

  • Cho, Dong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.6
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    • pp.1435-1441
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    • 2014
  • The fire took place in the synthetic heat transfer fluid boiler used in production process of medium density fiberboard. This study investigated pressure distribution of the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner. Pressure distribution at steady state in combustion furnace is 2~5mAq and pressure distribution at inverter under fault condition in combustion furnace is 10~-53mAq. The decrement of coil thickness measurement for synthetic heat transfer fluid boiler is 0~5mm.

Measurement of Nitric Oxide in the Differential Diagnosis of Lymphocytic Pleural Effusion (림프구성 흉막염의 감별 진단에서 NO(nitric oxide)의 측정)

  • Kim, Tae-Hyung;Sohn, Jang Won;Yoon, Ho Joo;Shin, Dong Ho;Park, Sung Soo
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.4
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    • pp.361-367
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    • 2005
  • Background : Differential diagnosis of lymphocytic pleural effusion is difficult even with many laboratory findings. Nitric oxide(NO) level is higher in the sputum or exhaled breath of patients with active pulmonary tuberculosis than in those without tuberculosis. In addition, there are some reports about the increased level of NO metabolites in body fluids of cancer patients. However, there is no data on the NO levels in the pleural fluid of patients with tuberculous pleurisy. Method : The serum and pleural fluid NO in the patients with acute lymphocytic pleural effusion were analyzed. Results : Of total 27 patients, there were 14 males and average age of patients was 48 years. The final diagnosis was tuberculous pleurisy in 17 cases and malignant pleural effusion in 10. The pleural fluid NO level was $540.1{\pm}116.4{\mu}mol$ in the tuberculous pleurisy patients and $383.7{\pm}71.0{\mu}mol$ in the malignant pleural effusion patients. The serum NO level was $624.7{\pm}142.0{\mu}mol$ in tuberculous pleurisy patients and $394.4{\pm}90.4{\mu}mol$ in malignant pleural effusion patients. There was no significant difference in the serum and pleural fluid NO level between the two groups. The NO level in the pleural fluid showed a significant correlations with the pleural fluid neutrophil count, the pleural fluid/serum protein ratio, and pleural fluid/serum albumin ratio (p<0.05 in each). The protein concentration, leukocyte and lymphocyte count in the pleural fluid were significantly higher in the tuberculous pleurisy patients than the malignant pleural effusion patients (p<0.05 in each). Conclusion : NO is not a suitable marker for a differential diagnosis of lymphocytic pleural effusion. However, the NO level in the pleural fluid might be associated with the neutrophil recruitment and protein leakage in the pleural space.

Tumour Markers in Peritoneal Washing Fluid - Contribution to Cytology

  • Yildirim, Mustafa;Suren, Dinc;Yildiz, Mustafa;Alikanoglu, Arsenal Sezgin;Kaya, Vildan;Doluoglu, Suleyman Gunhan;Aydin, Ozgur;Yilmaz, Necat;Sezer, Cem;Karaca, Mehmet
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.1027-1030
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    • 2013
  • Background: Peritoneal washing cytology (PWC) that shows the microscopic intra-peritoneal spread of gynaecologic cancers is not used in staging but is known as prognostic factor and effective in planning the intensity of the therapy. False negative or false positive results clearly affect the ability to make the best decision for therapy. In this study we assessed levels of tumour markers, carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125) and carbohydrate antigen (CA19-9), in peritoneal washing fluid to establish any possible contribution to the peritoneal washing cytology in patients operated for gynaecologic cancer. Materials and Methods: Preoperative tumour markers were studied in serum of blood samples obtained from the patients for preoperative evaluation of a gynaecologic operation. In the same group peritoneal tumour markers were studied in the washing fluid obtained for intraoperative cytological evaluation. Results: This study included a total of 94 patients, 62 with malignant and 32 with benign histopathology. The sensitivity of the cytological examination was found to be 21% with a specificity of 100%. When evaluated with CEA the sensitivity of the cytological examination has increased to 37%. Conclusions: In addition to examination of PWC, the level of CEA, a tumour marker, in peritoneal washing fluid can make a diagnostic contribution. Determining the level of CEA in peritoneal washing fluid will be useful in the management of gynaecologic cancers.