• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.761-766
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• 2018

Droplet-based microfluidic device has led to transformational new approaches in various applications including materials synthesis and high-throughput screening. However, efforts are required to enhance the production rate to industrial scale because of low production rate in a single droplet generator. In here, we present a method for enhancing production rate of monodisperse droplets via parallelization of flow-focusing generators. For this, we fabricated a three-dimensional monolithic elastomer device (3D MED) that has the 3D channel structures in a single layer, using a double-sided imprinting method. We demonstrated that the production rate of monodisperse droplet is increased by controlling the flow rate of continuous and dispersed phases in 3D MED with 8 droplet generators. Thus, we anticipate that this microfluidic system will be used in wide area including microparticle synthesis and screening system via encapsulation of various materials and cells in monodisperse droplets.

• Journal of Society of Preventive Korean Medicine
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• v.19 no.3
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• pp.155-170
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• 2015

Objective : Jaeumgeonbitang have been used in Korean medicine for many centuries as a therapuetic agent of vertigo. JAE was extract of Jaeumgeonbitang adding Evodiae Fructus. The effects of JAE on the cerebral blood flow and blood pressure is not known. This study was designed to investigate the effects of JAE on the ischemic crebral injuries. Method : We performed to investigate effects of JAE on the changes of regional cerebral blood flow(rCBF) and mean arterial blood pressure (MABP) in normal and ischemic rats, and further to determine the mechanism and cytokines production ($IL-1{\beta}$, $TNF-{\alpha}$, IL-10, $TGF-{\beta}$) of JAE. Results : In normal rats, JAE significantly increased rCBF and significantly decreased MABP in a dose-dependent manner. This result suggested that JAE significantly increased rCBF by dilating pial arterial diameter. Increase of JAE-induced rCBF was significantly inhibited by the pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase, and was significantly inhibited by methylene blue ($10{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Decrease of JAE-induced MABP was significantly increased by the pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase. So, these results suggested that the mechanism of JAE was mediated by cyclooxygenase. In ischemic rat, the rCBF was significantly and stably increased by JAE (10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in Control group. In cytokine production of serum by drawing from femoral arterial blood at 1 hr after reperfusion, Sample group (JAE 10 mg/kg treated group) was significantly decreased $IL-1{\beta}$ and $TNF-{\alpha}$ production compared with Control group. In cytokine production of serum by drawing from femoral arterial blood at 1 hr after reperfusion, Sample group was significantly increased IL-10 production compared with Control group. Conclusion : These results suggested that JAE was significantly and stably increased regional cerebral blood flow by inhibited $IL-1{\beta}$ and $TNF-{\alpha}$ production, and increased IL-10 production.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.757-763
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• 2000

In vehicle exhaust systems the sound attenuation and the reduction of flow losses are often two competing demands. The present study considers a fully vehicle exhaust system and investigates experimentally both the sound attenuation and the flow performance of production configurations including the catalyst, the resonator, and the muffler. Dynamometer experiments have been This study is on the development of a new muffler composed of a valve system using an elasticity of spring. The valve system conducted with the daewoo 1500cc Lanos engine with speeds ranging from 1000 to 5000 rpm. Measurements include the flow rates, the temperatures and the absolute dynamic pressures of the hot exhaust gases at point locations. The present study describes the experimental aspects of an ongoing effort to validate and use the nonlinear fluid dynamic models in the time-domain for the prediction of the acoustic and power performance of firing internal combustion engines with full production exhaust systems.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.241-246
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• 2000

Gas hydrates are solid solutions when water molecules are linked through hydrogen bondin create host lattice cavities that can enclose a large variety of guest gas molecules. The natural hydrate crystal may exist at low temperature above the normal freezing point of water and pressure greater than about 30 bars. A lot of quantities of natural gas hydrates exists in the ear many production schemes are being studied. In the present investigation, depressurization method considered to predict the production of gas and the simulation of the two phase flow - gas and - in porous media is being carried out. The simulation show about the fluid flow in porous have a variety of applications in industry. Results provide the appearance of gas and water prod the pressure profile, the saturation of gas/ water/ hydrates profiles and the location of the pl front.

• Journal of Korean Society of Rural Planning
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• v.7 no.2 s.14
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• pp.13-25
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• 2001

Runoff and water quality was monitored from a watershed with small-scale livestock production farms. To evaluate pollution potential, land use, population, the size of livestock production of each farm, and livestock management method were surveyed. Climate and stream flow data were measured. Water samples were taken periodically for base flow conditions and some storm events. Pollutant loading was estimated by flow volume and concentrations of constituents. Delivery ratio of pollutant load was determined using estimated pollutant load.

• IE interfaces
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• v.5 no.1
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• pp.35-46
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• 1992

This paper deals with analysis of material handling system efficiency of a heat-exchanger manufacturing line. This line is a typical flow shop type assembly line which consists of 10 steps of assembly stations. Each station have one or two workers who assemble and move components for the job, and no special transporters for component's movement. Therfore, all the workers are involoved in unnecessary moving activities which decrease overall production efficiencies of the line. To improve productivities, production outputs and worker's job performances for this assembly line, the several alternatives are considered such as installing new conveyor lines and automatic guided vehicle(AGV) system. Analyzing economic feasibilities and responses of the system alternatives, an experimental simulation model is built suing SIMAN Ver. 3. 5 simulation language with CINEMA package for animation of the process flow. Through this animation process a vivid picturial analysis could performed on the process flow.

• Industrial Engineering and Management Systems
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• v.15 no.3
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• pp.206-214
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• 2016

This paper deals with the no-wait flow shop scheduling problem in order to minimize the total time to complete the schedule or makespan. It is introduced a constructive heuristic which builds the production schedule from job partial sequences by using an appropriate mechanism of insertion. An extensive computational experiment has been performed to evaluate the performance of proposed heuristic. Experimental results have clearly shown that the presented heuristic provides better solutions than those from the best heuristics existing.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.27-31
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• 2021

VI probe, which is one of various in-situ plasma monitoring sensor, is frequently used for in-situ process monitoring in mass production environment. In this paper, we correlated the plasma etch results with VI probe data with the small amount of gas flow rate changes to propose usefulness of the VI probe in real-time process monitoring. Several different sized contact holes were employed for the etch experiment, and the etched profiles were measured by scanning electron microscope (SEM). Although the shape of etched hole did not show satisfactory relationship with VI probe data, the chamber status changed along the incremental/decremental modification of the amount of gas flow was successfully observed in terms of impedance monitoring.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.344-349
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• 1998

The purpose of this study was carried out to investigate the effect of scoparone(6, 7-dimethoxyco-umarin) on liver function. Sprague-Dawley rats were treated with scoparone at a dose of 20mg/kg body weight for 5 days. Hepatic bile flow, liver weight, BSP(bromosulfophthalein) biliary excretion, alanine aminotransferase(ALT) and aspartate aminotransferase(AST) activities, malondialdehyde production and lactate dehydrogenase(LDH) release were assayed. Among them, ALT and AST activities, malondialdehyde production and LDH release were assayed by using primary hepatocyte cultures at a concentration of 0.1mg/ml. Scoparone treatment had no effect on liver weight and hepatic bile flow. Scoparone treatment not only increased BSP biliary excretion, but also recovered the decreased BSP biliary excretion by CCl4, Also scoparone significantly decreased with the increases of ALT and AST activities, malondialdehyde production and LDH release induced by CCl4. These results suggested that scoparone could protect the liver damage by chemicals via promoting the liver excretory function.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.290-291
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• 2001

The relationship between velocity, viscosity, diffusion coefficient, mass transfer coefficient and characteristic length and mass transfer data can be correlated by dimensionless relationship in electrolytic process. The performance of dyestuff removal was decreased as the flow rate of electrolyte was increased. It was due to the effect of retention time decreasing was superior to that of turbulent inlet mixing. Sh/Sc$\^$1/3/ vs Re plot for Al flat electrode did not showed the general tendency of the relationship between Sh/Sc$\^$1/3/ and Re. It can be thought that flow rate was not sufficiently high to increase the effect of mixing.