• Tribology and Lubricants
• /
• v.27 no.5
• /
• pp.240-248
• /
• 2011

Mechanical face seal installed in primary heat transport pump used for heavy water reactor prevents leakage of working fluid using thin working fluid film between primary seal ring and mating ring. If the leakage of working fluid exceeds the allowable volume, serious accident can be happened by the trouble of primary heat transport pump. The thinner fluid film exists between primary seal ring and mating ring, the less working fluid leaks out. On the other hand, if the thickness of fluid film is not enough, the life of mechanical face seal will be reduced by friction and wear. Therefore appropriate design is necessary to maximize the performance and life of mechanical face seal. In this study, numerical analysis using finite volume method was conducted to investigate the performance of mechanical face seals which have same deep straight groove and 11 different net coning values. As results, equilibrium clearance between primary seal ring and mating ring, leakage volume of working fluid, friction torque on sealing surface and stiffness of working fluid film were obtained. With increasing net coning value, equilibrium clearance and leakage volume increase, and friction torque and stiffness of fluid film decrease.

• International Journal of Fluid Machinery and Systems
• /
• v.6 no.1
• /
• pp.1-10
• /
• 2013

Jet pump is one type of artificial lifts and is used when depth and deviation of producing wells increases and pressure depletion occurs. In the present study, numerical analysis has been carried out to analyze the flow behavior and find the performance of the jet pump. Reynolds-averaged Navier Stokes equations were solved and k-${\varepsilon}$ turbulence model was used for simulations. Water and light oil as primary fluids were used to pump water, light oil and heavy oil. The ratios of area and length to diameter of the mixing tube were considered as design parameters. The pump efficiency was considered to maximize for the downhole conditions. It was found that the increase in viscosity and density of the secondary fluid reduced efficiency of the system. Water as primary fluid produced better efficiency than the light oil. It was also found that the longer throat length increased efficiency upto 40% if light oil was used as primary fluid and secondary fluid viscosity was 350 cSt.

• The Korean Journal of Cytopathology
• /
• v.6 no.2
• /
• pp.125-132
• /
• 1995

Cytodiagnosis of pleural and ascitic fluid is a commonly performed laboratory examination. Especially, positivity for malignant cells in effusion cytology is very effective and also presents the first sign of malignancy in unknown primary site of the tumor. We examined each 34 cases of pleural and ascitic fluid cytologic specimen diagnosed as metastatic tumor, which was selected among 964 pleural fluid cytology cases and 662 ascitic fluid cytology cases from September 1989 to June 1995. Among the pleural fluid cytology specimens examined, 34 specimens were positive in 27 patients. The lung was the most frequent primary site(44%), followed by the stomach (12%), lymphoreticular neoplasm(12%), pancreas(3%) and colon(3%). And the cases of unknown primary site with positive pleural biopsy alone were 24%. Among trio ascitic fluid cytology specimens examined, 34 specimens were positive in 29 patients. The most common primary neoplasms. were carcinomas of ovary(32%), stomach(22%), colon(6%), breast(3%), pancreas(3%), and lung(3%) and lymphoreticular neoplasms(3%) The metastatic tumor was predominantly adenocarcinoma type in both pleural(82%) and ascitic(91%) fluid. The study of metastatic adeno- carcinoma in effusion from lung, ovary, and stomach was undertaken to find distinctive features for the identification of the primary site. The smears of metastatic pulmonary adenocarcinoma had a tendency to show high grade pleomorphism and many large tight cell clusters, whereas that of the ovarian adenocarcinoma showed low grade pleomorphism with abundant intracytoplasmic vacuoles in relatively clear background. That of the stomach revealed the intermediate features.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.11a
• /
• pp.384-389
• /
• 1999

Most document consists of primary content and supporting material, such as footnotes, detailed explanations, and illustrations, and the related supporting materials are linked as hypertext on web document. However the content of hypertext links Is appeared in the new windows on present web browser. Then the user will leave the primary material, may lose the entire context, and must have some difficulties to return to the primary context when the interest disappears. Using the technique for fluid links, we can solve these problems easily. If the mouse is putted on the link, the related material is presented in between lines or at margin maintaining the context of primary material. In this paper, we introduce the various browsing techniques using fluid links, analyze the forms and the features, and then we propose the best way to implement inJava.

• Journal of information and communication convergence engineering
• /
• v.1 no.2
• /
• pp.88-92
• /
• 2003

Most document consists of primary content and supporting material, such as footnotes, detailed explanations, and illustrations, and the related supporting materials are linked as hypertext on web document. However, the content of hypertext links is appeared in the new windows on present web browser. Then the user will leave the primary material, may lose the entire context, and must have some difficulties to return to the primary context when the interest disappears. Using the technique for fluid links, we can solve these problems easily. If the mouse is putted on the link, the related material is presented in between lines or at margin maintaining the context of primary material. In this paper, we introduce the various browsing techniques using fluid links, analyze the forms and the features, and then we propose the way to implement in Java.

• Journal of computational fluids engineering
• /
• v.14 no.2
• /
• pp.9-18
• /
• 2009

The cargo containment system (CCS) for ships carrying cryogenic fluid consists of at least two levels of barriers and insulation layers. It is because, even though there is a small amount of leak through the primary barrier, the liquid tight secondary barrier blocks further leakage of the cryogenic fluid. However, once the secondary barrier is damaged, it is highly possible that the leaked cryogenic fluid flows through the flat joint made of glass wool and reaches the inner hull of the ship. The primary objective of the present study is to investigate the influence of the damage extent in the secondary barrier on the amount of leaked cryogenic fluid reaching the inner hull and the temperature distribution there. Simulation results using a computational fluid dynamics tool were compared with the experimental data for the leaked cryogenic fluid flow and evaporation in the secondary insulation layer. The experimental and computational results suggest that, unless there is a massive leak, the cryogenic fluid mostly evaporates in the insulation layer and does not reach the inner hull in the state of liquid.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.6
• /
• pp.714-724
• /
• 1985

Two-phase(air-solid, air-liquid droplet) turbulent round jet has been analyzed numerically using two equation turbulence model. The mean motion of suspending particles in air has been treated as the secondary fluid with virtual density and eddy viscosity. In this paper, the local mean velocity of secondary fluid is not assumed to be the same as that of the primary one. Dissipation rate of turbulent kinetic energy which arises because the particles can not catch up with the turbulent fluctuations of the primary fluid has been modelled by using the concept of Kolmogorov's spectral energy transfer. Numerical computations were performed for flows with different volume fraction of the dispersed phase and the diameter of particle. Results show that the total rate of turbulent energy dissipation, turbulent intensities and spreading rate of jets are reduced by the increase of volume fraction of dispersed phase. However it does not show consistent tendency with increasing the particle diameter. This investigation also shows that presence of particles in the fluid modifies the structure of the primary fluid flow significantly. Predicted velocity profiles and turbulence properties qualitatively agree with available data.

• The Korean Journal of Cytopathology
• /
• v.8 no.1
• /
• pp.35-46
• /
• 1997

The authors reviewed 167 malignant effusions from 110 patients, of which the primary site was established on the basis of either biopsy or surgical resection of the primary neoplasm. Main factors analysed were the distribution of primary organs and the cytohistoiogic correlation of body cavity effusions. The 167 fluid specimens from 110 patients consisted of 90 cases(53.9%) of pleural, 68(40.7%) of peritoneal, and 9(5.4%) of pericardial origins. Histologically they consisted of 82 cases(74.5%) of adenocarcinoma, 8(7.3%) of malignant lymphoma, 6(5.5%) of squamous ceil carcinoma, and 3(2.7%) of small cell carcinoma. The most common site among the primary lesions was the stomach in 25 cases(22.7%) followed by the lung in 21(19.1%), ovary on 17(15.5%), and breast in 7(6.4%). As for the distribution of primary tumors in adenocarcinoma, the most common site was lung un 16 cases (48.5%) in pleural fluid and stomach in 22(48.9%) in peritoneal fluid. In pericardial effusions, all 5 cases were from the lung. As a whole, the cytologic findings of malignant effusion were fairly representative of histologic characteristics of primary lesions. Thus, when the primary lesion Is unknown, careful evaluation of effusion cytology is presumed to be a helpful tooi for tracing the primary tumor.

• The Korean Journal of Cytopathology
• /
• v.11 no.2
• /
• pp.65-73
• /
• 2000

Cytologlc evaluation of cerebrospinal fluid(CSF) is an effective mean for diagnosing many disorders involving the central nervous systems(CNS). One of the most important reasons for cytologic examination of CSF is to detect metastatic or primary neoplasms of the CNS. We did a retrospective study of 1,438 CSF specimens obtained between 1992 and 1996. A total of 1,205 adult and 233 pediatric CSF specimens from 947 patients were accessed at the Department of Pathology of Seoul National University Hospital and Children's Hospital, respectively. Among 1,438 CSF cytology specimens, 169 cases(11.8%, 77 patients) including 135 adult cases(59 patients) and 34 pediatric cases(18 patients) were positive for malignant cells. Diagnoses included 50 metastatic carcinomas(adult, 60; pediatric, 0); 46 malignant lymphomas(adult, 44; pediatric, 2); 21 leukemias(adult, 20; pediatric, 1); 4 retinoblastomas(adult, 0; pediatric 4); 2 rhabdomyosarcomas(adult, 0; pediatric, 2); 1 multiple myeloma(adult, 1; pediatric, 0), and 35 primary CNS neoplasms(adult, 10; pediatric, 25). The most commonly identified metastatic carcinomas in adults were adenocarcinoma. Their primary sites were the lung, gastrointestinal tract, and breast in order of frequency. The most common primary CNS neoplasm in children was medulloblastoma.

• The Korean Journal of Cytopathology
• /
• v.16 no.2
• /
• pp.110-114
• /
• 2005

Primary leptomeningeal glioblastomatosis is a rare and fatal tumor of the central nervous system, the condition is characterized by diffuse infiltration of the tumor in the meninges without evidence of primary tumor within the brain or spinal cord. We reported an unusual case of leptomengial glioblastomatosis, which was detected by the consecutive cerebrospinal fluid (CSF) cytology with application of immunohistochemistry, in addition to its cytologic findings. A healthy 21 year old man, who was enlisted in the army, presented with a stuporous mental state and diffuse enhancement of meninges without evidence of primary mass lesion in the brain and spinal cord on magnetic resonance imaging(MRI). CSF cytology showed small loose clusters of tumor cells with single cells and lymphocytes. The tumor showed variable pleomorphism with coarse chromatin, irregular nuclear membranes and multi lobated nuclei. On immunohistochemical staining, the tumor cells were founded to be positive for GFAP. In conjunction with radiologic findings, brain biopsy confirmed the diagnosis of leptomenigeal glioblastomatosis. The use of immunohistochemistry is helpful in confirming CSF cytologic diagnosis in patients with primary leptomeningeal glioblastomatosis.