• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2003.11a
• /
• pp.217-229
• /
• 2003

Analysis of the elements affecting short circulation in highly integrated paper mills and identification of the interactions among these elements are very important tasks to prevent operational perturbations such as web breaks. In the present work a dynamic model for the short circulation is developed to analyze tuning methods for the outputs to follow set points during grade change operations. Steady state operation data are used to investigate dynamic characteristics of responses for input changes.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1997.05a
• /
• pp.458-463
• /
• 1997

A transient natural circulation behavior during a LOCA at hot-standby operation is evaluated for YGN Units 3/4. The plant initial condition is determined within the EOP limitation as suitable to hot-standby mode and the transient scenario is prepared as relevant to evaluation of transient natural circulation. A 0.4% cold leg break with loss of off-site power is calculated with RELAP5/MOD3.2, whose predictability has been verified for SBLOCA natural circulation test, S-NC-8B. Through one hour transient analysis, it is found that the plant has its own decay heat removal capability by natural circulation following a LOCA, at hot-standby mode. Additional calculation is performed to investigate an effect of HPSI flow on natural circulation.

• Journal of Chest Surgery
• /
• v.11 no.3
• /
• pp.296-302
• /
• 1978

This experiment was carried out to study the change of potassium before, during, and after extracorporeal circulation. Serum potassium and urinary potassium excretion were examined in 7 cases of patient who were taken open heart surgery using extracorporeal circulation. All of 7 cases were administered 10-25mEq of KC1 during extracorporeal circulation. Serum potassium was not changed significantly during, and after operation, but urinary potassium excretion was declined during extracorporeal circulation and tend to rise after extracorporeal circulation. This result showed no remarkable relation of serum potassium and urinary potassium excretion.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.676-679
• /
• 2007

This paper describes an experiment facility to measure the circulation characteristics of a water/steam receiver at various heat fluxes. The natural circulation type receiver was considered in this study. The experiment facility was designed to satisfy circulation balance with an appropriate scale down. As a result, riser tube inner diameter was 7.4 mm and water circulation was 0.319 kg/s. Downcomer tube inner diameter by circulation balance was 9.52 mm and the quality was from 0 to 0.23.

• Journal of Korean Neurosurgical Society
• /
• v.40 no.3
• /
• pp.159-163
• /
• 2006

Objective : Unique Internal carotid artery angiographic findings have been found especially in very poor grade aneurysmal subarachnoid hemorrhage[SAH] patients before and during the endovascular coiling. The author investigates their patterns and classifies them into lour subtypes. Methods : Among Hunt&Hess grade IV, V SAH patients, the author could gather eight patients who showed abnormal intracranial circulation in cerebral catheter-based angiography. Results : The author introduces new term 'misery collaterals' first and has classified them into four types with the case illustrations. Type 1 is the worst condition defined as almost no intracranial circulation. Type 2 is the condition of little intracranial circulation with contrast filling just only at vessels of brain base, type 3 is of no or little cortical circulation with contrast filling at bilateral large vessels of brain base through circle of Willis channel and type 4 is of visible bilateral cortical circulation but delayed intracranial circulation time. The prognosis of these eight patients showed misery collaterals were disappointed. Conclusion : These finding can be used as the supportive information in deciding a management plan in poor grade SAH patients.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.385-390
• /
• 2000

In this study we propose the computational model for the coronary circulation. The bypass from left ventricle is also considered. Lumped parameter model with three compartments in the coronary circulation is implemented in this study. We connected the coronary artery compartment with left ventricle to explain the bypass procedure from left ventricle. The asymmetric resistance is assumed in the bypass line from left ventricle. The present numerical method is tested for normal coronary circulation and the results are compared with the existing computational work. The bypass simulation is conducted and the flow pattern is delineated. The effect of shunt resistance and coronary compliance to circulation is investigated for the better design of the bypass shunt.

• Journal of the korean society of oceanography
• /
• v.38 no.1
• /
• pp.11-16
• /
• 2003

The three dimensional structure of thermohaline circulation in a D-plane is investigated using a conceptual two layer model and a scaling argument. In this simple model, the water mass formation region is excluded. The upper layer represents the oceans above the main thermocline. The lower layer represents the deep ocean below the thermocline and is much thicker than the upper layer. In each layer, geostrophy and the linear vorticity balance are assumed. The cross interfacial velocity that compensates for the deep water mass formation balances downward heat diffusion from the top. From the above relations, we can determine the thickness of the upper layer, which is the same as thermocline depth. The results we get is basically the same as that we get for an f-plane ocean or the classical thermocline theory. Mass budget using the velocity scales from the scaling argument shows that western boundary and interior transports are much larger than the net meridional transport. Therefore in the thermohaline circulation, horizontal circulation is much stronger than the vertical circulation occuring on a meridional plane.

• Journal of Korean Society on Water Environment
• /
• v.21 no.6
• /
• pp.595-601
• /
• 2005

In this research, effects of water circulation on phosphorus release from sediment into water body were studied. Sediments sampled at the Daechung Lake were used for the column experiments with circulation and non-circulation conditions. Deaeration coefficient, $K_1$ and reaeration coefficient, $K_2$ of non-circulation condition were 0.133 and 0, respectively, while $K_1$ and $K_2$ for circulation condition were 0.46 and 0.018, respectively. Oxidation Reduction Potential (ORP) showed a linear relationship with dissolved oxygen (DO) when DO is over 2 mg/L. Phosphorus concentration induced by phosphorus release from sediment was highly dependent upon DO, ORP, and pH. Under anaerobic condition, phosphorus release rate was higher for $Fe^{2+}$-bounded phosphorus compared to that of $Ca^{2+}$-bounded phosphorus.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.1
• /
• pp.25-28
• /
• 2015

In this study, a basic research on artificial liver was performed for its application to people on the waiting list of liver transplant or patients with hepatic insufficiency. Artificial livers are generally classified into mechanic type, bioartificial type, and hybrid type. An extracorporeal circulation device was examined herein, which is indispensable in the application of an artificial liver, for its effectiveness in supporting the recovery of liver functions. Extracorporeal circulation system is a treatment and life-support system which sends out the patient's blood, removes toxicity by various methods, and then sends the blood back to the interior of the body. This study used an extracorporeal circulation system which enables the Plasma Perfusion by CVVH method, and applied the program of Bioateco corp. Animals with acute hepatic insufficiency were produced to apply the extracorporeal circulation device. As a result, their ammonia, bilirubin, SGOT, SGPT, and bile acid levels rose, confirming the liver function restoration in the experimental animals.

• Korean Chemical Engineering Research
• /
• v.53 no.4
• /
• pp.440-444
• /
• 2015

Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.