• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.5
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• pp.733-741
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• 2002

If a part of the poor solution from the absorber outlet is recirculated to the absorber inlet, the solution temperature at the solution spray pump can be reduced, and the solution flow rate in the absorber is increased. We have performed the experiments on the influences of the absorption chiller performance according to the ratio of the recirculation, defined as the ratio of the recirculation flow rate to the total solution flow rate at the absorber outlet. As increasing the ratio of the recirculation, the absorption capacity of the solution can be deteriorated. On the other hand, due to the increasing flow rate, the heat transfer rate can be enhanced. As a result, the performance of the absorber and the cooling capacity of the absorption chiller have nothing to do with the recirculation ratio, and the lifetime of the spray pump will be maintained.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.05a
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• pp.95-99
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• 2001

As a way to use energy effectively, the present study is aimed at investigating the performance characteristics of a Single Effect LiBr/Water Absorption Refrigerator using a low temperature driving heat-source. It was carried out by changing the driving heat-source temperature, the cold water outlet temperature(the refrigeration load), the cooling water inlet temperature, and the weak solution flow rate and this study compares the performance characteristics of refrigerator against the existence and non-existence of the Recirculation of the Weak solution which is used as a method to improve the performance of refrigerator. In case of Recirculation of the weak solution, more improved the Refrigeration Capacity and COP was obtained, and these effects became more larger in the high temperature of driving heat-source and large quantity of solution.

• Membrane and Water Treatment
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• v.13 no.1
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• pp.39-49
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• 2022

Seawater desalination is doubtlessly a viable option to supply fresh drinking water. Nevertheless, RO (reverse osmosis) desalination plants in specific areas may be intermittently operated to match the imbalance between water demand and supply. Although a handful of works have been done on other membrane systems, few studies have attempted to mitigate fouling in intermittent RO systems. Accordingly, the objectives of this paper were to examine the effect of the intermittent operation on RO fouling; and to compare four intermittent operation modes including feed solution recirculation, membrane storage in the feed solution, deionized water (DI) recirculation, and membrane storage in DI water. Results showed that intermittent operation reduced RO fouling under several conditions. However, the extents of fouling mitigation were different depending on the feed conditions, foulant types, and membrane lay-up methods. When the feed solution was recirculated during the lay-up, the restoration of the flux was less significant than that by the feed solution feed-up. The use of deionized water during the lay-up was effective to restore flux, especially when the feed solution contains scale-forming salts (CaSO₄) and/or colloidal silica.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.362-363
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• 2006

Ozonized DI water was supplied to make alkaline cleaning solutions to replace SCI chemicals in a bath with and without recirculation. With recirculation, low dissolved ozone and low pH cause lower particle removal efficiency (PRE) of 75%. However, direct supply of ozonized water with $NH_4OH$ to a bath without recirculation resulted in higher PRE over 93 %.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.2
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• pp.71-75
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• 2010

To investigate the intestinal absorption of a fibrinolytic and proteolytic lumbrokinase extracted from Eisenia andrei, we used rat everted gut sacs and an in situ closed-loop recirculation method. We extracted lumbrokinase from Eisenia andrei, and then raised polyclonal antibody against lumbrokinase. Fibrinolytic activity and proteolytic activity in the serosal side of rat everted gut sacs incubated with lumbrokinase showed dose- and time-dependent patterns. Immunological results obtained by western blotting serosal side solution using rat everted gut sacs method showed that lumbrokinase proteins between 33.6 and 54.7 kDa are absorbed mostly by the intestinal epithelium. Furthermore, MALDI- TOF mass spectrometric analysis of plasma fractions obtained by in situ recirculation method confirmed that lumbrokinase F1 is absorbed into blood. These results support the notion that lumbrokinase can be absorbed from mucosal lumen into blood by oral administration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1841-1851
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• 1999

Banyan network has been widely employed as a basic building block for ATM switches. But the banyan network has very low routing capacity because of the internal blocking problem. Hence, a dilated banyan network has been used as one solution that can overcome the internal blocking problem. However, tremendous network capacity is wasted in the dilated network In this paper, we propose a dilated banyan network with deflection routing and recirculation mechanism to fully utilize the wasted capacity. The performance of the proposed switch is analysed under uniform traffic assumption. Numerical and simulation results show that the proposed switch yields a significant improvement of the maximum throughput as compared that of the pure dilated banyan network.

• Journal of Korea Multimedia Society
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• v.19 no.11
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• pp.1891-1899
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• 2016

Recently food problem and crop disaster have been increased continuously because of the meteorological changes. These cause rising cost for crops continuously and irregularly. Some researchers have studied straight structure of device for hydroponics and plant factory previously to solve a fundamental part of these problems. However, there are several problems such as limited crop cultivation space, providing irregular nutrients for crops, and lack of monitoring interfaces. For them, we propose an optimal growth and development crops management system using light source tracking and recirculation of nutrient solution method to supply nutrient continuously based on IoT. In order to evaluate the performance of our system, we compared and analyzed in terms of two viewpoints, the tracking analysis for natural light source measurement and the growth of crops through artificial light, LED, respectively. We confirmed that the higher the duty ratio of LED, the larger the crop's size, particularly. As well as, for about 1 month, we compared with the existing natural light growing environment and that of our system. It was confirmed that the size of the crops grown through our system is about three times larger than that of natural light natural crops.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.11
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• pp.923-932
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• 2006

In this paper, reentering ratio and cooling capacity of individual cooling towers arrayed on a building roof were studied by a numerical method. The number of 16 cooling towers were divided into 4 banks. It was considered the summer prevailing wind characteristics as west wind and south wind of 5 m/s. It was also considered the roofwall types as the curtainwall and the louverwall that had the outdoor air intake louver in the curtainwall. In this case, the louver was suggested as the solution that could prevent reentering phenomenon due to recirculation and interference of the discharge air. In the case of the curtainwall, the averaged reentering ratio are predicted 13.3% and 24.4% for the west and south wind of 5 m/s, respectively. In the case of the louverwall, the averaged reentering ratio are predicted 2.5% and 9.7% for the west and south wind of 5 m/s, respectively. Therefore, the louverwall is a appropriate solution for reducing the reentering phenomenon.

• Journal of Chest Surgery
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• v.15 no.1
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• pp.35-39
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• 1982

Cold blood potassium cardioplegia, by two types of the infusion systems, was used in 45 patients who were undergone the open cardiac operation. Method A [in 25 patients] was the syringe infusion system and method B [in 20 patients] was the pump infusion system. Cold blood potassium cardioplegic solution was used less amount on method B than method A. Serum potassium was often increased significantly on method A as a result of excessive infusion of cold blood potassium cardioplegic solution. But method B, excessive infusion of cold blood potassium cardioplegic solution was prevented by reperfusion of the previous infused cold blood potassium cardioplegic solution through the recirculation system. Alteration of infused rate and concentration of potassium in cold blood potassium cardioplegic solution during infusion [which might be suggested on the method A] could be controlled on method B.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.569-572
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• 2002

In the present study, flow simulations of a solution pump fer an absorption chiller are performed. The results are compared to the experimental data. Since the cavitation is more likely to occur in a solution pump due to Its operation under vacuum condition, and the cavitation was not considered in the present computations, the computed and experimental results show large discrepancies. For more accurate performance prediction of a solution pump, a cavitation model is required in the flow simulation. Flows through an inducer are also studied to see the effect of design parameters on performance characteristics. It is shown from the results that, if not properly designed, recirculation legion may exist near the hub region of the Inducer, and the suction surface may experience higher pressure than the pressure surface of the inducer, which may deteriorate the performance.