• Korean Journal of Plant Taxonomy
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• v.35 no.1
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• pp.47-55
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• 2005

During the course of the field trip to Mt. Baekdu and Manchurian region especially along the border of North Korea, young flower buds were collected and fixed to analyze the meiotic configuration of chromosomes and to discuss the cytotaxonomic characteristics of these areas. A total of 29 taxa with 31 populations of vascular plants were analyzed chromosomally. Among them, 26 taxa with 28 populations were collected from Mt. Baekdu which include Papaver radicata var. pseudoradicata, Bupleurum euphorbioides, Oplopanax elatus, Silene jenisseensis, and Gentiana jamesii and three taxa collected from Manchurian region which include Scrophularia buergeriana, Ostericum grosseserratum and Callistephus chinensis. The first report of chromosome numbers were provided here for those species of Artemisia lagocephala as 2n = 9II, Cacalia komaroviana as 2n = 30II, Chrysanthemum zawadskii var. alpinum as 2n = 27II and Rodiola rosea as 2n = 11II,

• Proceedings of the Membrane Society of Korea Conference
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• 2002.07a
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• pp.1-12
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• 2002

Desalination by reverse osmosis (RO), which first entered commercial use in the 1970s, was initially mainly used for treating brackish water. Technological progress led to the development of an RO membrane enabling single-pass seawater desalination. Toyobo succeeded in developing a single-pass seawater desalination RO module composed of hollow fiber type membranes made of cellulose triacetate in 1978, and then in 1979 began production of the first commercially available double-element module. This double-element module has many advantages suitable for seawater desalination. It has high chlorine tolerance and high salt rejection, derived from the properties of the membrane material, and it is highly resistant to fouling and scaling matters due to the unique flow pattern and fiber bundle configuration. These advantages help to explain why the Toyobo double-element module has been used so successfully at the many seawater desalination plants around the world. Since the 1980s, large plants capable of desalinating several tens of thousands of cubic meters a day have sprung up around the Mediterranean and In the Middle East. The Jeddah RO Phase I Plant, which has a capacity of 56, 800m$^3$/day, went into operation in 1989. In 1994, the same sized Phase II Plant came on stream, giving the plant a huge total capacity of 113, 600m$^3$/day. The plant constructor Mitsubishi Heavy Industries, Ltd. (MHI), and the RO membrane manufacturer Toyobo Co., Ltd. In 1998, the world's largest RO seawater desalination plant in operation, which has a capacity of 128, 000m$^3$/day and is run by Saudi Arabia's Saline Water Conversion Corporation (SWCC), went into operation at Yanbu. RO seawater desalination technology has thus already reached the stage of full-scale commercial use. In order to encourage its wider use, however, RO desalination needs to be made more economical by lowering construction and water treatment costs. Toyobo has therefore developed a new economical RO desalination system by a recovery ratio of 60% using a high-pressure module with a high product flow rate. In 2000, Toyobo high recovery membrane module was selected for the largest seawater desalination plant in Japan, which has a capacity of 50, 000m$^3$/day.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1746-1755
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• 2003

Operating characteristics of a triple pressure reheat HRSG are analyzed using a commercial software package (Gate Cycle by GE Enter Software). The calculation routine determines all the design parameters including configuration and area of each heat exchanger. The off-design calculation part has the capability of simulating the effect of any operating parameters such as power load, process requirements, and operating mode, etc., on the transient performance of the plant. The arrangement of high-temperature and intermediate-temperature components of the HRSG is changed, and its effect on the steam turbine performance and HRSG characteristics is examined. It is shown that there could be a significant difference in HRSG sizes even though thermal performance is not in great deviation. From the viewpoint of both economics and steam turbine performance, it should be carefully reviewed whether the optimum design point could exist. Off-design performance could be one of the main factors in arranging components of the HRSG because power plants operate at various off-design conditions such as ambient temperature and gas turbine load, etc. It is shown that different heat exchanger configurations lead to different performances with ambient temperature, even though they have almost the same performances at design points.

• Journal of Ocean Engineering and Technology
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• v.28 no.2
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• pp.167-176
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• 2014

This paper proposes an optimum curve driving method for adeep-seabed mining robot(MineRo) in deep-sea soft ground. MineRo was designed as afour-row tracked vehicle. A study on the turning methods for the four-row tracked vehicle was conducted using three case by changing the velocity profile of each track. The configuration of the four-row tracked vehicle and soft ground equation are introduced, along with the dynamics analysis models of MineRo and soft ground, which were constructed using the commercial software DAFUL. Because the purpose of this study was to investigate a driving method on soft ground, the marine environment of the deep sea was not considered.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.4
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• pp.31-37
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• 2011

Pressurized Water Reactor Owners Group(PWROG) proposed and applied a risk-informed inservice inspection(RI-ISI) program to alternate existing ASME Section XI periodic inspections. The RI-ISI programs enhance overall safety by focusing inspections of piping at high safety significant(HSS) and locations where failure mechanisms are likely to be present, and by improving the effectiveness on inspection of components because the examination methods are based on the postulated failure mode and the configuration of the piping structural element. The RI-ISI programs can reduce NDE, man-rem exposure, costs of engineering analysis, outage duration and chance of complicating plant operations etc. RI-ISI methods of piping inservice inspection were applied on 3 units(KSNP : Korea Standard Nuclear Power Plant) and are scheduled to apply on the other units. In this paper, we compared and showed the results of the 2 units and we concluded that the RI-ISI application could enhance and maintain plant safety and give unquantifiable benefits.

• Progress in Superconductivity and Cryogenics
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• v.13 no.2
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• pp.21-24
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• 2011

Superconducting high gradient magnetic separation (HGMS) has advantages to treat wastewater because it can generate high magnetic field and achieve rapid purification. In this study superconducting HGMS was applied to remove impurities from the condenser water in thermal power plant. The condenser water contained mainly hematite and maghemite and it was highly magnetized than hematite. In the HGMS tests using a 6-T cryo-cooled Nb-Ti superconducting magnet, the turbidity of the condenser water was effectively reduced up to 99.6% and the result showed better performance than that of the 0.5-T permanent magnet test. The higher magnetic field was applied in the range of 1-6T, the more iron oxides were removed. The effect of magnetic filter configuration on the condenser water treatment was also investigated. Consequently superconducting HGMS system can be applicable to remove iron oxide impurities from condenser water in thermal power plant.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.9
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• pp.704-711
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• 2008

Integrated gasification combined cycle (IGCC) is an environment friendly method of using coal. Several commercial IGCC plants have been built worldwide during the past decade, and a domestic development project has also been launched recently. Operation and performance characteristics of a gas turbine in the IGCC plant deviates from those of original gas turbines due to several factors such as increased amount of fuel supply and integration with other components. In this study, performance of a gas turbine in the IGCC plant is analyzed considering its integration with the air separation unit (ASU). Influence of the degree of integration (split of air supplies to ASU from the auxiliary compressor and the gas turbine compressor) on the system performance is investigated. In addition, effect of modulating nitrogen return flow from the gasifier to the gas turbine on the operating characteristics of the gas turbine is examined.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.685-692
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• 2019

In this paper, the relationship between the angle control of the panel contributing to the optimum power generation efficiency of the solar power plant is investigated. For a total of eight months, one of the two plants with the same equipment configuration changed their angles every three months and the other plants did not change their angle. In this study, we propose a model that can maximize the power generation efficiency by comparing and analyzing the difference of power generation between stationary solar power station and stationary solar power station through simulation.

• Journal of Photoscience
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• v.9 no.2
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• pp.326-328
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• 2002

In many plant cells, the positions of chloroplasts change in response to changes in light conditions. In the epidermal cells of the aquatic angiosperm Vallisneria gigantea, the avoidance response of chloroplasts is induced specifically by irradiation with blue light of high intensity. Possible roles of actin cytoskeleton in the blue-light-induced avoidance response of chloroplasts were investigated by partial irradiation and phalloidin staining. We showed that the blue-light-dependent redistribution of chloroplasts was induced only in the limited area, where exposed to blue light, even in individual cells. In addition. in the exposed area, the configuration of actin filaments strikingly changed compared with that before the irradiation. Short and thick bundles of actin filaments surrounding the chloroplasts changed to much longer and thinner bundles with a more stretched array. In contrast, in the unexposed area, neither the distribution of chloroplasts nor the configuration of actin filaments exhibited any changes. Cytochalasin D and latrunculin B inhibited the avoidance response of chloroplasts concomitantly with the fragmentation of actin filaments. These results indicate that the reorganization of actin filaments plays a crucial role in the induction of avoidance response of chloroplasts.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.816-821
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• 2010

It has been achieved 109.1 kg/d of BOD reduction that is equivalent to the amount of BOD loading discharged from 21,880 persons and dramatic decrease of the fallout ratio against water quality of effluent, from 42% to 9%, through technical support on ISTPs to be applied by the ISMSGA at the upper area of Geongan river in Yong-In city. It was clearly revealed that the most efficient configuration for ISTP was a series of anaerobic tank, equalization basin, aerobic tank, sedimentation tank, and then effluent tank. Also, the major causes on the fallout ratio of ISTP resulted in the lack of management (67.5%) and imperfect facilities (32.5%). Then, when compared the quantity of water supply with the design capacity of ISTP, the design capacity was estimated as 1.8 or 2.4 folds larger than the real quantity of water supply so that it is essential to punctually consider the key factors such as an estimation methods, the specificity of commission operator and construction by high systematic technologies to improve the water quality for the future.