• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.3
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• pp.239-245
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• 2003

In the nuclear power plant, emergency core coolant system (ECCS) is furnished at reactor coolant system (RCS) in order to cool down high temperature water in case of emergency. However, in this coolant system, thermal stratification phenomenon can occur due to coolant leaking in the check valve. The thermal stratification produces excessive thermal stresses at the pipe wall so as to yield thermal fatigue crack (TFC) accident. In the present study, effects of turbulence penetration on the thermal stratification into T-branches with square cross-section in the modeled ECCS are analysed numerically. $textsc{k}$-$\varepsilon$ model is employed to calculate the Reynolds stresses in momentum equations. Results show that the length and strength of thermal stratification are primarily affected by the leak flow rate of coolant and the Reynolds number of the main flow in the duct. Turbulence penetration into the T-branch of ECCS shows two counteracting effects on the thermal stratification. Heat transport by turbulence penetration from the main duct to leaking flow region may enhance thermal stratification while the turbulent diffusion may weaken it.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.12
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• pp.628-637
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• 2017

This study was conducted to present an effective control method for the common duct system to uniformly discharge volume flow rate exhausted from the kitchen and bathroom of each household in an apartment regardless of the position of household. Since the common duct system is installed vertically and the ventilator is installed in the terminal, the static pressure of each household decreases when vertical height increases. Therefore, the volume flow rate exhausted from each household is different. In order to improve such a phenomenon, a constant air volume damper shall be installed in a branch duct coupled with a common vertical duct system. The selected ventilator should also be able to handle the maximum volume flow rate considering diversity factor. Therefore, a uniform volume flow rate must be exhausted from all households where the hood is operated. This paper mainly focuses on suggestion of an optimum exhaust control method by comparing exhaust performance of each household according to the presence or absence of a constant air volume damper.

• Journal of Veterinary Clinics
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• v.35 no.6
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• pp.299-301
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• 2018

A 7-year-old intact female Shih-Tzu with chylothorax was presented. Percutaneous popliteal computed tomographic lymphangiography was performed to evaluate the thoracic duct and seek any potential cause of chylothorax. Despite two attempts, visualization of the thoracic duct failed and perianal subcutaneous computed tomographic lymphangiography with injection of iodinated, nonionic water-soluble contrast medium (0.6 ml/kg) was performed. A single branch of intact thoracic duct and dilated and tortuous lymphatics were detected. It was diagnosed as idiopathic chylothorax. Perianal subcutaneous lymphangiography is considered a less-invasive, easy and reliable method to visualize lymphatics in patients with chylothorax.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.29-36
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• 1999

The objective of this study is to analyse the flow field in the branching duct by visualizing the flow phenomena using the PIV system. A bifurcation model is fabricated with transparent acrylic resin to visualize the whole flow field with the PIV system. Water was used as the working fluid and the conifer powder as the tracer particles. The single-frame and two-frame methods of the PIV system and 2-frame of the grey level correlation method are applied to obtain the velocity vectors from the images captured in the flow filed. The velocity distributions in a lid-driven cavity flow are compared with the so-called standard experimental data, which was obtained from by 4-frame method in order to validate experimental results of the PIV measurements. The flow patterns of a Newtonian fluid in a branching duct were successfully visualized by using the PIV system and the sub-pixel and the area interpolation method were used to obtain the final velocity vectors. The velocity vectors obtained from the PIV system are in good agreement with the numerical results of the 3-dimensional branch flow. The results of numerical analyses and the PIV experiments for the three-dimensional flows in the branch ing duct show the recirculation zone distal to the branching point and the sizes of the recirculation length and height of the tow different methods are in good agreement.

• BMB Reports
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• v.50 no.12
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• pp.621-627
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• 2017

We previously reported the involvement of zinc-finger protein 143 (ZNF143) on cancer cell motility in colon cancer cells. Here, ZNF143 was further characterized in breast cancer. Immunohistochemistry was used to determine the expression of ZNF143 in normal tissues and in tissues from metastatic breast cancer at various stages. Notably, ZNF143 was selectively expressed in duct and gland epithelium of normal breast tissues, which decreased when the tissue became malignant. To determine the molecular mechanism how ZNF143 affects breast cancer progression, it was knocked down by infecting benign breast cancer cells with short-hairpin (sh) RNA-lentiviral particles against ZNF143 (MCF7 sh-ZNF143). MCF7 sh-ZNF143 cells showed different cell-cell contacts and actin filament (F-actin) structures when compared with MCF7 sh-Control cells. In migration and invasion assays, ZNF143 knockdown induced increased cellular motility in breast carcinoma cells. This was reduced by the recovery of ZNF143 expression. Taken together, these results suggest that ZNF143 expression contributes to breast cancer progression.

• Korean Journal of Head & Neck Oncology
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• v.28 no.2
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• pp.125-128
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• 2012

Salivary duct carcinoma(SDC) is a highly malignant tumor of the salivary gland. The tumor is clinically characterized by a rapid onset and progression, the neoplasm is often associated with pain and facial paralysis. The nodal recurrence rate is high, and distant metastasis is common. SDC resembles high-grade breast ductal carcinoma. Curative surgical resection and postoperative radiation were the mainstay of the treatment. If facial paralysis is present, a radical parotidectomy is mandatory. Regardless of the primary location of SDC, ipsilateral functional neck dissection is indicated, because regional lymphatic spread has to be expected in the majority of patients already at time of diagnosis. If there is minor gland involvement, a bilateral neck dissection should be performed, because lymphatic drainage may occur to the contralateral side. The survival of SDC patient is poor, with most dying within three years. We experienced a unique case of SDC in parotid deep lobe. We report the clinicopathologic features of this tumor with a review of literature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.1
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• pp.123-130
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• 1999

The objective of the current study is to understand steady 3-dimensional flow phenomena in a bifurcated duct experimentally. A bifurcation model is fabricated with transparent acrylic resin to visualize the whole flow field with the PIV system. The gray level cross-correlation method is applied to the image processing algorithm. The subpixel and the area interpolation methods are used to obtain the final velocity vectors. The finite volume predictions are used to analyze the flow patterns in the bifurcation model. The results of the computer simulation and the PIV experiment for three-dimensional flow show the recirculation zone and the formation of the paired secondary flow distal to the apex of the bifurcation model. The results obtained with the two methods also show that the branch flow strongly strikes the inner wall due to the inertial effect and accompanied helical motion as it flows toward the outer wall.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.7
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• pp.918-927
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• 1999

In the fully developed internal flow fields, there are complex transition flows caused by interaction of the cross flow and jet when jet is Injected Into the flow. These interactions are studied by means of the flow visualization methods. An instantaneous laser tomographic method is used to reveal the physical mechanism and the structure of vortices formation in the branch pipe flow. The velocity range of cross flow of the pipe is 0.7m/s and the corresponding Reynolds number $R_{cf}$, based on the duct height is $5.6{\times}10^3$, diameter/height ratios(d/H) 0.14 and velocity ratios 3.0. Oil mist with the size of $10{\mu}m$ diameter is used for the scattering particle. The instantaneous topological features of the vortex ring roll-up of the jet shear layer and characteristics of this flow are studied in detail by performing flow visualization in rectangular duct flow. It is found that the formation and roll-up of ring vortices is a periodic phenomenon. The detailed topology of the vortices in the near field of a cross -flow jet and the mechanism associated with them give enforced hints of vortex breakdown within the vortex system due to the interaction of the jet and the cross-flow.

• Journal of the Korean Society of Visualization
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• v.16 no.2
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• pp.7-15
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• 2018

The fluid-flow characteristics of flue-gas-recirculation (FGR) system can have a significant effect on system efficiency of a sintering plant. The flow characteristics in the system were investigated. A sintering plant with FGR system was modeled. Numerical visualization was performed and flow characteristics were analyzed. Characteristics of the flow distribution of the branch ducts, the inflow of air into the recirculating hood, and the flow in the hood were discussed. Based on the results three suggestions were proposed: (1) distribution of branch duct flowrate upstream, (2) installation of external air ducts in the hood, and (3) installation of baffles at the hood corners. The suggestions were tested numerical and experimental visualization methods. The suggestions were effective and confirmed to be applicable to the actual sinter plant.

• Journal of Digestive Cancer Research
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• v.9 no.1
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• pp.1-7
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• 2021

The length, the frequency, and the methods of surveillance for intraductal papillary mucinous neoplasm (IPMN) of the pancreas are still debating. According to the recent guidelines, IPMN is stratified into "high-risk stigmata" or absolute indication and "worrisome features" or relative indication as a guide in managing these patients, either those with resection of the lesion or those under surveillance. The risk of malignant transformation was quite low for branch duct-IPMNs without worrisome features or high risk stigmata. However, because the incidence rate of pancreatic cancer in these patients increase linearly with time, continued long-term surveillance is therefore important for patients with low-risk, as well as higher-risk, IPMN. Considering the high prevalence of malignancy, main duct-IPMN should be treated by surgical resection. Among patients with these type IPMNs, segmental dilatation of the main pancreatic duct without any mural nodules and larger than 10 mm of main pancreatic duct might not be immediately resected and need very careful examination and observation. The risk related to a major pancreatic resection must balance the risk of surveillance in patients with IPMN of the pancreas who have co-morbidity and are elderly.