• Journal of Institute of Control, Robotics and Systems
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• v.4 no.3
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• pp.321-328
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• 1998

When we control the level of the steam generator in the nuclear power plants, a swell and shrink arises from many disturbances such as feed water rate, feed water temperature, main steam flow rate, and coolant temperature. If we use the conventional type of PI controller in this system, we will not have stability during controlling at lower power, the removal function of disturbances, and a load follow-up control effectively. In this paper, we study the application of a 2-Degree of Freedom(2-DOF) PID controller to the level control of the steam. generator of nuclear power plants through the simulation and the experimental steam generator. We use the parameters $\alpha$, $\beta$, $\gamma$ of the 2-DOF PID controller for the removal of disturbances and the parameters Kp,Ti,Td of the conventional type of PID controller for controlling setpoint. The back-propagation learning algorithm of neural network is used for tuning the 2-DOF PID controller. We can find satisfactory results of the removal of the disturbances and the tracking function in the change of setpoint through the simulation and experimental steam generator.

• Progress in Superconductivity and Cryogenics
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• v.23 no.3
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• pp.14-19
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• 2021

The reduction of carbon dioxide emissions becomes a global issue, the main source of carbon dioxide emissions in the Asian region is the energy conversion sector, especially coal-fired power plants. We are working to develop technologies that will at least limit the increase in carbon dioxide emissions from the thermal power plants as one way to reduce carbon dioxide emissions. Our research aims to reduce carbon dioxide emissions by removing iron oxide scale from the feedwater system of thermal power plants using a superconducting high-gradient magnetic separation (HGMS) system, thereby reducing the loss of power generation efficiency. In this paper, the background of thermal power plants in Asia is outlined, followed by a case study of the introduction of a chemical cleaning line at an actual thermal power plant in Japan, and the possibility of introducing it into the thermal power plants in China based on the results.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.93-104
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• 1997

The objective of this study is to develop a method to reduce arsenic concentrations in contaminated water. This work is also aimed at increasing the specificity of membrane separation processes. Arsenic in contaminated waters is often present in the form of negatively charged oxyanions. These are relatively small molecules which cannot be separated directly by ultrafiltration. Oxyanions can be captured by polyelectrolytes and separated by ultrafiltration. Results will be presented on the use of two polyelectrolytes; polyethylenimine (PEI) and poly-diallyl dimethyl ammonium chloride (DADMAC) at various feed concentrations. A semi-continuous process utilizing PEI in a circulation loop was tested. The restfits indicate that better than 99.6 % recovery (permeate concentration < 0.001 $\mu$g/L) can be achieved based on an initial arsenic concentration of 300 $\mu$g/L. The results indicate that this treatment method is suitable as a main treatment process for drinking water or a polishing step after arsenic precipitation.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.40-47
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• 2011

KSNPs(Korea Standard Nuclear Power Plant) have been applied the break exclusion criteria to the high energy lines passing through containment penetration area to ensure that piping failures would not cause the loss of containment isolation function, and to reduce the resulting dynamic effects. Systems with the criteria are the Main Steam system, Feed Water system, Steam Generator Blowdown system, and Chemical & Volume Control system. In accordance with FSAR(Final Safety Analysis Report), a 100% volumetric examination by augmented in-service inspection of all pipe welds appled the break exclusion criteria is required for the break exclusion application piping. However, it is difficult to fully satisfy the requirements of inspection because 12", 8" and 6" weldolet weldments of Main Steam pipe line have complex structural shapes. To resolve the difficulty on the application of conventional UT(Ultrasonic Testing) technique, realistic mock-ups and UT calibration blocks were made. Simulations of conventional UT were performed utilizing CIVA, a commercial NDE(Nondestructive Examination) simulation software. Phased array UT experiments were performed through mock-up including artificial notch type flaws. A phased array UT technique is finally developed to improve the reliability of ultrasonic test at main steam line pipe to 12", 8" and 6" branch connection weld.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1651-1658
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• 2008

This study was conducted to determine the effects of dietary supplementation of either 100 mg/kg chito-oligosaccharide (COS) or chlortetracycline (CTC) with corn-soybean-fish meal on immunity in broiler chickens. A total of 147 one-day old male broiler chicks were randomly allocated to 3 treatments with 7 replicate pens per treatment and 7 birds per pen. The experimental diets consisted of a control diet based on corn, soybean and fish meal without COS and any antibiotic supplement and similar diets supplemented with either CTC (80 mg/kg from d 1 to 21 and 50 mg/kg from d 22 to 42) or COS (100 mg/kg from d 1 to 42). During the entire experimental period, all birds had ad libitum access to diets and water. The main immune organ indices, T-lymphocyte proliferation, serum cytokine concentrations, serum NO level and serum iNOS activity were measured on d 21 and d 42. On d 21, broilers fed 100 mg/kg COS had improved (p<0.01) indices of spleen, thymus, and bursa of Fabricius compared with the control and CTC birds. Birds receiving 100 mg/kg COS had higher (p<0.05) serum concentrations of $IL-1{\beta}$, IL-6, IgM, NO and iNOS than birds on the control treatment. Serum $Ca^{2+}$ level of birds fed 100 mg/kg COS tended to be higher (p = 0.049) than in birds fed CTC. On d 42, the birds fed 100 mg/kg COS had higher (p<0.05) concentrations of TNF-${\alpha}$ and IgM in serum than birds in both the CTC and control treatments. Birds fed 100 mg/kg COS had a higher concentration of IFN-$\gamma$ than the control group. In conclusion, dietary supplementation of COS appeared to improve the immunity of broilers by promoting the weight of the main immune organs, increasing IgM secretion, stimulating microphages to release $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 and IFN-$\gamma$, and activating iNOS to induce NO.

• Parasites, Hosts and Diseases
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• v.43 no.3 s.135
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• pp.75-92
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• 2005

Extensive previous studies on taxonomy, behavior/bionomics and control of Anopheles sinensis are reviewed and summarized. Recent molecular identification revealed that the population of An. sinensis complex includes An. sinensis, An. pullus, An. lesteri and at least two new species, and An. yatsushiroensis is synonmy of An. pullus. An. sinensis is the main vector specie of vivax malaria in Korea. Larvae of An. sinensis breed in wide range of habitats which are naturally-made clean water, stagnant or flowing; main habitats include rice fields, ditches, streams, irrigation cannals, marshes, ponds, ground pools, etc. Their host preferences are highly zoophilic. Human blood rate is very low ($0.7-1.7\%$); nevertheless An. sinensis readily feeds on man when domestic animals are not found near by. They feed on hosts throughout the night from dusk to dawn with a peak period of 02:00-04:00 hours; they are slightly more exophagic (biting outdoors); much larger numbers come into the room when light is on. Main resting places are outdoors such as grasses, vegetable fields and rice fields. A mark-release-recapture study resulted that $37.1\%$ was recaptured within 1 km, $29.4\%$ at 1-3 km, $21.1\%$ at 3-6 km, $10.3\%$ at 6-9 km and $2.1\%$ at 9-12 km distance. An. sinensis hibernate outdoors (mostly under part of dense grasses) during October-March. At the end of the hibernation period (March-April) they feed on cows at daytime. Until today any single measure to effectively control An. sinensis population has not been found. Indoor residual spray with a long-lasting insecticide can not reduce vector population densities, but shorten their life spans in some degree, so contributes to malaria control.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.37-45
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• 2002

The development process of KSR-III propulsion feeding system is subscripted. The purpose of propulsion feeding system is to feed a certain amount of propellant from propellant tank to engine by the end of combustion. Pressure-fed liquid rocket, KSR-III has the unique characteristics of both pressure regulator and cavitation venturi as a passive flow control device. Main parameters of feeding system are confirmed by both water test and CFD(전산유체) technique. Flow control effect with venturi is confirmed by water test. Initial stabilization characteristic of pressure regulator is confirmed by real propellant test. And, to avoid the effect of resonance between rocket and feeding system, this article deal with POGO(포고) analysis to the feeding system.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.9
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• pp.1262-1275
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• 2013

Awamori is produced by fermenting steamed indica rice. Awamori-pressed lees is a by-product of the Awamori production process. Tofu lees is a by-product of the Tofu production process. Research was conducted to test if dried Awamori-pressed lees and Tofu lees can be used as a mixed feed ingredient for raising male goats. Eighteen male kids were divided into three groups of six animals (control feed group (CFG), Awamori-pressed lees mixed feed group (AMFG), Tofu lees mixed feed group (TMFG)). The CFG used feed containing 20% soybean meal as the main protein source, while the AMFG and TMFG used feed mixed with 20% dried Awamori-pressed lees or dried Tofu lees. The groups were fed mixed feed (volume to provide 100 g/d increase in body weight) and alfalfa hay cubes (2.0 kg/d) twice a day (10:00, 16:00). Klein grass hay and water was given ad libitum. Hay intake was measured at 10:00 and 16:00. Body weight and size measurements were taken once a month. At the end of the experiment, a blood sample was drawn from the jugular vein of each animal and the carcass characteristics, the physical and chemical characteristics of loin were analyzed. DCP and TDN intakes in AMFG and TMFG showed no significant difference to the CFG. Cumulative measurements of growth in body weight and size over the 10 mo period in the AMFG and TMFG were similar to the CFG. Blood parameter values were similar to those in normal goats. Dressing carcass weight and percentages, and total weight of meat in the AMFG were similar to that in the CFG, but smaller in the TMFG. The compressed meat juice ratio was higher in both the TMFG and AMFG than the CFG. While the fat in corn, Awamori-pressed lees, and Tofu lees contains more than 50% linoleic acid, the loin fat in both the AMFG and TMFG was very low in linoleic acid due to the increase in the content of oleic acid, stearic acid, and palmitic acid. This indicates that feeding on AMF and TMF does not inhibit hydrogenation by ruminal microorganisms. As in the CFG, the total essential and non-essential amino acids in the loin of the AMFG and TMFG were well balanced. Compared to the CFG, the AMFG and TMFG were high in taurine and carnosine. The results indicate dried Awamori-pressed lees and Tofu lees can be used as a feed ingredient for raising male goats.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.502-514
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• 2012

When ruminants consume dry forage, they also drink large volumes of water. The objective of this study was to clarify which factor produced when feed boluses enter the rumen is mainly responsible for the marked increase in water intake in the second hour of the 2 h feeding period in large-type goats fed on dry forage for 2 h twice daily. Six large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 2 to 6 years, weighing $85.1{\pm}4.89kg$) were used in two experiments. In experiment 1, the water deprivation (WD) control and the water availability (WA) treatment were conducted to compare changes in water intake during and after dry forage feeding. In experiment 2, a normal feeding conditions (NFC) control and a feed bolus removal (FBR) treatment were carried out to investigate whether decrease in circulating plasma volume or increase in plasma osmolality is mainly responsible for the marked increase in water intake in the second hour of the 2 h feeding period. The results of experiment 1 showed that in the WA treatment, small amounts of water were consumed during the first hour of feeding while the majority of water intake was observed during the second hour of the 2 h feeding period. Therefore, the amounts of water consumed in the second hour of the 2 h feeding period accounted for 82.8% of the total water intake. The results of experiment 2 indicated that in comparison with the NFC control, decrease in plasma volume in the FBR treatment, which was indicated by increase in hematocrit and plasma total protein concentrations, was higher (p<0.05) in the second hour of the 2 h feeding period. However, plasma osmolality in the FBR treatment was lower (p<0.05) than compared to the NFC control from 30 min after the start of feeding. Therefore, thirst level in the FBR treatment was 82.7% less (p<0.01) compared with that in the NFC control upon conclusion of the 30 min drinking period. The results of the study indicate that the increased plasma osmolality in the second hour of the 2 h feeding period is the main physiological stimulating factor of water intake during and after dry forage feeding in large-type goats.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.