• Journal of ILASS-Korea
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• v.1 no.3
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• pp.37-50
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• 1996

Computational fluid dynamics was used to optimize an A/C duct. Three dimensional flow analysis in an automotive A/C duct was performed computationally using various turbulence models and compared numerical predictions such as outlet flow split, surface pressure distribution along the duct to experimental data. Additionally, we studied the effect of location variation of 2nd branch on exit flow ratio and could find optimal location of 2nd branch. The design of an A/C duct was modeled and calculated to enhance the airflow distribution in each outlet using the STAR-CD computational fluid dynamics software. In results, modified $k-\varepsilon$ turbulence model allows a successful prediction of static pressure distribution particulary at around strong curvature but little improvement flow split. In the future, adoption of CFD to design an A/C duct with modified $k-\varepsilon$ model will bring benefits of producing more accurate prediction, and also give designers more detail information much more than now.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.2
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• pp.135-142
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• 2015

The Anti-Rolling Tank(ART) has an advantage over the other roll stabilizing devices, when ship is staying and working at one site of sea. An important design point of ART is the tank tuning, that is, matching the tank natural period to the ship's roll natural period. Since the load condition and consequently the roll natural period of ship is to be changed widely, the natural period of ART also has to be changed widely. In case of the existing U-tube type ART with a single layer duct, the tank natural period can be changed in a relatively narrow range. This paper suggests a new U-tube type ART system using a double layer duct to enable wide change of ART natural period. Through the roll experiments performed in regular beam waves for a box-type model ship, it is shown that the double layer duct ART has about two times wider period range and a better reducing effect of roll magnitude than the single layer duct ART.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.197-202
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• 1990

Mechanical obstruction of the common hepatic duct includes the following causes ; choledocholithiasis, sclerosis, cholangitis, pancreatic carcinoma, cholangiocarcinoma, postoperative stricture, primary hepatic duct carcinoma, enlarged cystic duct lymph nodes, and metastatic nodal involvement of the porta hepatis. Partial mechanical obstruction of the common hepatic duct caused by impaction of stones and inflammation surrounding the vicinity of the neck of the gallbladder had been reported on the "syndrome del conducto hepatico" in 1948 by Mirizzi. Nowadays, this disease was named by Mirizzi syndrome. Mirizzi syndrome is a rare entity of common hepatic duct obstruction that results from an inflammatory response secondary to a gallstone impacted in the cystic duct or neck of the gallbladder. It results from an almost parallel course and low insertion of the cystic duct into the common hepatic duct. In a varient of Mirizzi's syndrome, the cause of the common hepatic duct obstruction was a primary cystic duct carcinoma rather than gallstone disease. A 71-year-old man was admitted with a four-day history of right upper quadrant abdominal pain. Past medical history was unremarkable. On physical examination, the patient had a temperature of $38^{\circ}C$, icteric sclera and right upper quadrant tenderness. Pertinent laboratory findings included WBC 18,000/$cm^2$;albumin 2.6g/dl(normal 3.9-5.1) ; SGOT 183u/L(normal 0-50) ; SGPT167u/L(normal 0-65) ; bilirubin, 8.2mg/dl(normal 0-1) with the direct bilirubin, 4.4mg/dl(normal 0-0.4). Ultrasonography revealed a dilated extrahepatic biliary tree. ERCP showed that the superior margin was angular and more consistent with a calculus causing partial CHD obstruction(Mirizzi syndrome). At surgery a diseased gallbladder containing calculi was found. In addition, there was two calculi partially eroding through the proximal portion of the cystic duct and compressing the common hepatic duct. A cholecystectomy and excision of common bile duct was performed, with Roux-en-Y hepaticojejunostomy. The postoperative course was uneventful.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.23-29
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• 1996

This study was carried out to identify the gross anatomical and radiographic characteristics of the nasolacrimal system of the Korean native goat. The results were as follows : The nasolacrimal system are composed of two lacrimal ducts, two lacrimal, canaliculus, one lacrimal sac and one nasolacrimal duct. The nasolacrimal duct was divided into proximal, middle and distal portion. The nasolacrimal duct took a straight course to be paralleled with nasal bones and opened close to the nostril on the medial surface of the alar fold. The diameter of lacrimal punctum, the length of eyelid margin to lacrimal punctum, the length of canaliculus and the diameter of lacrimal sac were 0.82~0.90mm, 1.06~1.54mm, 5.65~6.30mm and 1.77~2.06mm, respectively. The length of proximal, middle and distal nasolacrimal duct were 36.84~40.00mm, 23.53~24.31mm and 14.55~14.73mm, respectively. The diameter of the orifice of nasolacrimal duct, the length of lateral margin of nostril to orifice of nasolacrimal duct and the length of dorsum to orifice of nasolacrimal duct were 1.29~1.33mm, 12.97~12.53mm and 15.24~16.11mm. The skull index of Korean native goat was not significantly different from the length of nasolacrimal duct.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.424-428
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• 2001

Keratoconjunctivitis sicca (KCS) is a relatively common eye disease in the dog, Reduction or arrest of aqueous tear production by lacrimal glands results in quantitative alteration of the precorneal tear film (PTF) and KCS may result. A dog with a presumptive diagnosis of KCS referred was used for the study of KCS. Cytological and histopathologic examination is performed, and the various types of medical and surgical treatment are studied, including the operation of parotid duct transposition (PDT). This report described unilateral KCS in a dog of unknown etiology who responded to PDT.

• Applied Microscopy
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• v.20 no.1
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• pp.36-50
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• 1990

This experiment was performed to study the morphological responses of the enterochromaffin cells in the duodenal mucosa of rabbit following bile duct ligation. Adult male rabbits were divided into normal, sham operation and experimental groups. Bile duct ligation was performed under ether anesthesia and animals were sacrificed on the 1st, 3rd, 5th, 7th and 14th day after operation. Mucosal specimens from the duodenum were prefixed with 2.5% glutaraldehyde-1.5% paraformaldehyde(0.1M Millonig's phosphate buffer, pH 7.3), followed by postfixation with 1% osmium tetroxide(0.1M Millonig's phosphate buffer, pH 7.3), and embedded within araldite mixture. The sections were cut on a LKB-V ultratome, and observed under a JEM 100CX II electron miroscope. The results were as follow; 1. Irregularities of the nuclei of the enterochromaffin cells were noticed from the 1st day after bile duct ligation, and concentration of the chromatin in the nucleus was more frequently observed on the 7th and the 14th day. 2. The granular endoplasmic reticulum and Golgi complex of the enterochromaffin cell were more developed than those of the normal on the 1st day after bile duct ligation, but they showed poor organization from the 3rd day. 3. Amount of the microfilaments in the enterochromaffin cell was significantly increased from the 5th day after bile duct ligation and they were more frequently observed in the vicinity of the nucleus. 4. Vacuoles with various electron densities in the enterochromaffin cell were increased in number from the 3rd day after bile duct ligation. 5. Glycogen-like particles in the enterochromaffin cell were frequently observed on the 3rd and the 5th day after bile duct ligation. 6. In the early stage of the ligation of bile duct, in the enterochromaffin cells, well developed intracellular organelles, such as granular endoplasmic reticulum and Golgi apparatus were pronounced. But, in the later stage, the cells contained poor organelles, with the some structural sign of necrotic change.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.501-506
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• 2000

We examined the antifibrotic effect of a methanol extract from Stephania tetrandra (ST) on experimental liver fibrosis. liver fibrosis was induced by bile duct ligation and scission (BDL/S) in rats. In BDL/S rats, activity levels of aspartate transaminase (AST), alanine transaminse (ALT), alkaline phosphatase (ALP), concentration of total bilirubin in serum, and hydroxyproline content of the liver were significantly increased. The ST treatment (either 100 ${m}g/kg/day$ or 200 ${m}g/kg/day$, p.o. for 4 weeks) in BDL/S rats reduced the serum AST, ALT and ALP activity levels significantly (p<0.01). Similarly, when compared to the control group, the concentration of hydroxyproline in the livers of the BDL/S rats treated with 100${m}g$ or 200${m}g$ ST treated rats decreased by 40% and 33% respectively, when compared to the BDL/S control group (p<0.01). The morphological characteristics of fibrotic liver that were observed in the BDL/S control group, improved in the ST treated BDL/S group. In the fibrotic liver of BDL/S rats treated with ST, a marked reduction in the numbers of alpha smooth muscle cell actin positive stellate cells was observed. These results indicate that doses of either 100 or 200 ${m}g/kg/day$ of methanol extract from S. tetrandra, had an antifibrotic effect in rats with liver fibrosis induced by bile duct ligation and scission.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.541-546
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• 1987

An experimental study has been conducted to investigate the suction performance of a designed inlet. Total pressure distortion in the inlet S-duct was measured and the effect of lip thickness and throat area was analyzed. The volume flow rate of air into the turbojet engine was controlled to observe the effect of engine RPM to the total pressure distortion. The pressure data from 36 air tubes were obtained using scanivalve, pressure transducer, and visicoder system.

• Korean Journal of Radiology
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• v.25 no.5
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• pp.501-503
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• 2024

• Journal of computational fluids engineering
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• v.2 no.2
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• pp.44-50
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• 1997

Accurate simulation of jet plume exhausting into the open space as well as onto the opposing wall is of interest both numerically and physically; the latter, from a system designer's point of view. In the current work, Navier-Stokes computation is undertaken to capture the flow pattern of a supersonic jet impinging onto a rectangular duct which deflects the vertical jet horizontally. Of particular interest are the flow structure in the jet exhaust area, pressure pattern and the magnitude of pressure force at the bottom wall. Usefulness of present characteristic boundary condition applied at the exiting plane of the duct is demonstrated by capturing such complex flow structures for different lengths of the deflection duct.