• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.8 s.239
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• pp.911-920
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• 2005

The present study investigates heat/mass transfer and flow characteristics in a ribbed rotating passage with turning region. The duct has an aspect ratio (W/H) of 0.5 and a hydraulic diameter ($D_h$) of 26.67 mm. Rib turbulators are attached in the parallel arrangement on the leading and trailing surfaces of the passage. The ribs have a rectangular cross section of 2 m (e) $\times$ 3 m (w) and an attack angle of $70^{\circ}$. The pitch-to-rib height ratio (p/e) is 7.5, and the rib height-to-hydraulic diameter ratio (e/$D_h$) is 0.075. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is constant at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for the same conditions using a commercial code FLUENT 6.1. The results show that a pair of vortex cells are generated due to the symmetric geometry of the rib arrangement, and heat/mass transfer is augmented up to $Sh/Sh_0=2.9$ averagely, which is higher than that of the cross-ribbed case presented in the previous study for the stationary case. With the passage rotation, the main flow in the first-pass deflects toward the trailing surface and the heat transfer is enhanced on the trailing surface. In the second-pass, the flow enlarges the vortex cell close to the leading surface, and the small vortex cell on the trailing surface side contracts to disappear as the passage rotates faster. At the highest rotation number ($R_O=0.20$), the turn-induced single vortex cell becomes identical regardless of the rib configuration so that similar local heat/mass transfer distributions are observed in the fuming region for the cross- and parallel-ribbed case.

• Archives of Pharmacal Research
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• v.29 no.3
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• pp.241-248
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• 2006

Angiotensin converting enzyme (ACE) inhibitors have cardioprotective effects in different species including human. This cardioprotective effect is mainly due to the inhibition of bradykinin (BK) degradation rather than inhibition of the conversion of angiotensin I to angiotensir. II. Bradykinin, a nonapeptide, has been considered to be the potential target for various enzymes including ACE, neutral endopeptidase 24.11, carboxypeptidase M, carboxypeptidase N, proline aminopeptidase, endopeptidase 24.15, and meprin. In the present study, the coronary vascular beds of Sprague Dawley rat isolated hearts were perfused (single passage) with Krebs solution alone or with different concentrations of BK i.e. $2.75{\times}10^{-10},\;10^{-7},\;10^{-6}\;and\;10^{-5}M$ solution. Percent degradation of BK was determined by radioimmunoassay. The degradation products of BK after passing through the isolated rat-hearts were determined using RP-HPLC and mass spectroscopy. All the four doses of BK significantly decreased the perfusion pressure during their passage through the hearts. The percentage degradation of all four doses was decreased as the concentration of drug was increased, implying saturation of a fixed number of active sites involved in BK degradation. Bradykinin during a single passage through the hearts degraded to give [1-7]-BK as the major metabolite, and [1-8]-BK as a minor metabolite, detected on HPLC. Mass spectroscopy not only confirmed the presence of these two metabolites but also detected traces of [1-5]-BK and arginine. These findings showed that primarily ACE is the major cardiac enzyme involved in the degradation of bradykinin during a single passage through the coronary vascular of bed the healthy rat heart, while carboxypeptidase M may have a minor role.

• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.719-724
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• 2010

The purpose of this study was to survey public preferences for dining space image styles depending on the types of passage rites in Korea and to determine potential differences in public preferences for dining space image styles depending on the types of passage rites in terms of various general characteristics such as gender, age, family type, and preference for the image and color styles of the dining space. As a result, this study determined the following: According to a public preference survey of dining space image styles depending on the type of passage rites, our respondents showed the highest preference for casual images (27.1%) at a party for a 100-day-old baby. Additionally, our respondents showed the highest preference for casual images (27.4%) when celebrating a baby's first birthday but showed the highest preference for romantic images (35.8%) when celebrating a baby girl's first birthday. Our respondents showed the highest preference for casual images (21.4%) for graduation ceremonies. Our respondents showed the highest preference for classic images (21.7%) at coming-of-age ceremonies for new adult men, but also showed highest preference for elegant images (26.2%) at coming-of-age ceremonies for new adult women. Moreover, the respondents showed highest preference for classic images (41.0%) at traditional wedding ceremonies but elegant images (24.1%) at modern wedding ceremonies. In contrast, the respondents showed highest preference for classic images (31.3%) for a 60th birthday party. The highest preference for classic images (28.9%) was found for a diamond wedding ceremony. Respondents showed highest preference for classic images (30.4%) for a funeral ceremony Finally, our respondents showed highest preference for classic images (32.5%) at memorial services (religious ceremonies).

• Proceedings of the KOR-BRONCHOESO Conference
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• 1978.06a
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• pp.4.1-4
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• 1978

The foreign bodies in the food and air passages are frequently observed in the field of otolaryngology, and the foreign bodies in the air passages have much significance in clinical practice because they may cause sudden death. A statistical study was done on 95 cases of foreign bodies in the food and air passages who had visited department of otolaryngology, Chung-Ang university from June, 1968 to April, 1978. The results were as follows; 1. The total cases of foreign bodies in the food and air passages was 95; 89 cases (93.7%) were in the food passage and the remaining (6.3%) were in the air passage. The ratio between the food passage and air passage was about 14. 8 to 1.0. 2. In distribution by sex, 64 cases (67.4%) were in male patients and the remaining 31 cases (32.6%) were in female patients. The ratio between male and female was 2.1 to 1.0. 3. The kinds of foreign bodies in the food in the order of their frequency, were coin, gogame stone and pebble. In the air passages, the peanut and bean were most frequently found. 4. In distribution by age, 64 cases (67.4%) of all foreign bodies were found in children under 5 year old, and coin was the most common kind of foreign body. Except for meat, almost all of foreign bodies were found in children under 10 year old. 5. There was chronologically no significant tendency in incidence; the incidence, however, had decreased during recent 2 years. 6. In the location of foreign bodies in the food passage, 70 cases (78.7%) were found at the first esophageal narrowing. Meat was more frequently found at second esophageal narrowing associated with cicatrical stenosis. Almost all of foreign bodies in the air passage was found in bronchi; 3 cases were in the right side of bronchi, and 2 cases were in the left side of bronchi and 1 case was in glottic region. 7. In duration of lodgement, 50 cases (52.6%) visited our hospital within 24 hours, and 3 cases after 30 days. 8. Under topical anesthesia, 83 cases (93.3%) of the foreign bodies in the food passage were removed by esophagoscopy, by 6 cases (6.7%) failed to be removed. All of the foreign bodies of the air passages (6 cases) were removed by bronchoscopy. Among them, 5 cases under 5 years old were removed by inferior bronchoscopy through tracheostomy site.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.2
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• pp.157-165
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• 2007

Purpose: Ingested foreign bodies are removed by endoscopy, surgery or spontaneous passage, however, the decision of therapeutic modality chosen depends on the type, size, shape and location of the ingested foreign bodies. Therefore, this study was conducted to investigate the rate and characteristics of foreign bodies that were passed spontaneously out of the intestine. Methods: One hundred and sixty patients who visited Samsung Medical Center for treatment of gastrointestinal foreign bodies between January 2001 to July 2007 were enrolled in this study. Related data was colleted by reviewing the medical records of patients with proven foreign bodies retrospectively, as well as by conducting phone interviews with the parents of the patients. All cases were classified based on the nature and location of the ingested foreign body, as well as whether it was treated by spontaneous passage. Results: Of the 160 cases involving the passage of foreign bodies in children were included in this study (95 boys and 65 girls), endoscopic removals, operative removals or spontaneous passages were conducted in 80, 3 and 77 patients, respectively. The spontaneous passage rates for each type of object were as follows; coins (36.5%), bead and baduk stones (83.3%), long and sharp materials (52.6%), magnets (69.2%) and disc batteries (50.0%). In cases involving round-shaped foreign bodies, such as coins, the diverse spontaneous passage rates were more diverse. When foreign bodies were stuck below esophagus, similar sized coins and baduk stones had spontaneous passage rates greater than 80% regardless of age. Conclusion: It is better for clinicians to wait for spontaneous passage to occur in cases involving coins or round-shaped foreign bodies that are located at or below the stomach.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.110-116
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• 2000

Duck viral hepatitis is an acutic, highly infectious viral disease of young ducklings. The most practical means for controlling duck viral hepatitis is the vaccination of ducklings or of a breeding stock. We attempted to develop a vaccine strain of duck hepatitis virus (DHV) using a Korean isolate by serial chicken embryo passages. The propagation of DHV in chicken embryos was carried 140 passages. After the $50^{th}$ passage, of which the virus was non-pathogenic for ducklings, approximately every $20^{th}$ passage of the virus was tested for vaccinal efficacy. Both the $70^{th}$ and $90^{th}$ passage of the virus gave good protection against challenge infection to a DHV-DRL reference strain(type 1) and a virulent Korean isolate. The $110^{th}$, $125^{th}$ and $140^{th}$ passage of the virus were less protective than the $70^{th}$ and $90^{th}$ passage, which means that more than $110^{th}$ passage may lead to over-attenuation of the virus. Ducklings vaccinated with the chicken-embryo-adapted virus by oral, intramuscular or eye drop administration showed earlier resistance to challenge infection from 3 to 7 days postvaccination. Of the above methods, ducklings vaccinated intramuscularly presented the most rapid resistance against challenge. The minimum immune dose of the chicken-embryo-adapted virus in ducklings was also studied. Ducklings inoculated with a dose of $10^{2.0}\;ELD_{50}$ and below were not fully protected against challenge with a virulent DHV, showing a protection rate of 67% to 73%, but ducklings inoculated with a dose of $10^{3.0}\;ELD_{50}$ and over were completely protected. The virus yield of the chicken-embryo-adapted DHV was examined at 24hrs and 48hrs of the incubation time in the allantoic fluid, embryo head and embryo minus head of the embryonating egg. In all three components, the titer of the virus was higher at 48 hours than that at 24 hours after incubation. And the titer of the virus was higher in the embryo minus head, embryo head and the allantoic fluid, in order. Field trials for evaluating the efficacy of the attenuated DHV as a live vaccine were done in duck farms with about 25% mortality of flocks resulting from duck viral hepatitis. After the use of the experimental vaccine, the mortality due to duck viral hepatitis was dramatically reduced in the farms. These results indicated that the attenuated DHV using a Korean isolate could be a good candidate as a live vaccine strain of DHV in Korea.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.173-184
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• 2012

In order to investigate the fluctuation rates [FR] of phytoplankton after passage through a cooling system, the standing crops, chlorophyll a concentrations and carbon assimilation number of phytoplankton were surveyed at intake and outlet at Wolsong nuclear power plant [NPP] from July 2006 to June 2008. As a result, the total mean standing crops of phytoplankton were $1.0{\times}10^6\;cells\;L^{-1}$ and $7.3{\times}10^5\;cells\;L^{-1}$ at intake and outlet, respectively. The FR of phytoplankton by passage through the cooling system [PTCS] was 27.0%. Among them, the FR of microplankton and nanoplankton were 34.1% and 12.4%, respectively. In addition, the FR of diatoms and dinoflagellateswere 33.9% and 29.7%, respectively. These results showed the entrainment effects on microplankton and diatoms by PTCS were higher than those of nanoplankton and dinoflagellates. The FR of total chlorophyll a concentrations were 54.4%, and the FR of microplankton, nanoplankton and picoplankton were 58.9%, 38.5%, and 52.4%, respectively. So the entrainment effects on microplankton by PTCS were higher than those of nanoplankton and picoplankton. The mean FR of carbon assimilation number of phytoplankton was 57.6%, and the seasonal variations of FR of carbon assimilation number ranged from 47.5% to 76.8%. Our results indicated that the phytoplankton species responded differently to power plant operating conditions such as elevated temperature, chlorination, and mechanical impacts.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.83-89
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• 1981

Japanese encephalitis has been prevalent for long time in the Far East and many patients have been reported in both South East and Mid-West Asia recently. Recently, vaccine was used in prevention of this viral disease of man which was derived from formalin inactivated virus inoculated into mouse brain, but live attenuated active vaccine for human is not developed yet. Author inoculated Japanese encephalitis virus into several cell culture strains for development of live attenuated encephalitis virus strain and the results were as follows: 1. Japanese encephalitis virus was inactivated rapidly in cell free medium at $36^{\circ}C$ and totally inactivated by 72 hours. 2. In growth curve of Japanese encephalitis virus in HeLa cell cultures, maximal multiplication of the virus was occured at 4th day and virus multiplication was continued for at least 12 days. 3. After succeeding passage of the virus in HeLa cell cultures and human esophagus epithelial cell cultures, infectivity of virus for mice was disappeared from 2nd passage in HeLa cell cultures and 3rd passage in esophagus epithelial cell cultures. 4. In inoculation to monkey kidney epithelial cells and chick embryo cell cultures, infectivity of the virus for mice was continued after 10th passages.

• Tribology and Lubricants
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• v.25 no.3
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• pp.150-156
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• 2009

Precise leakage prediction for annular type seals of turbomachinery is necessary for enhancing their efficiency and various prediction methods have been developed. As the seal passage is designed intricately, the analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage is limited. In order to improve the seal leakage prediction, full Navier-Stokes Equations with turbulent model derived in the seal flow passage have to be solved. In this study, 3D CFD (Computational Fluid Dynamics) analysis has been performed for predicting leakage of various non-contact type anular seals using FLUENT. Compared to the results by Bulk-flow model analysis, experiment, and 2D CFD analysis, the result of 3D CFD analysis shows improvement in predicting seal leakage, especially for the parallel grooved pump seal.