• Progress in Superconductivity and Cryogenics
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• v.21 no.2
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• pp.22-25
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• 2019

The superconducting magnetic separation system has been developing to separate the iron oxide scale from the feed water of the thermal power plant. The accumulation in the boiler lowers the heat exchange rate or in the worst case damages it. For this reason, in order to prevent scale generation, controlling pH and redox potential is employed. However, these methods are not sufficient and then the chemical cleaning is performed regularly. A superconducting magnetic separation system is investigated for removing iron oxide scale in a feed water system. Water supply conditions of the thermal power plant are as follows, flow rate 400 t / h, flow speed 0.2 m / s, pressure 2 MPa, temperature $160-200^{\circ}C$, amount of scale generation 50 - 120 t / 2 years. The main iron oxide scale is magnetite (ferromagnetic substance) and its particle size is several tens ${\mu}m$. As the first step we are considering to introduce the system to the chemical cleaning process of the thermal power plant instead of the thermal power plant itself. The current status of development will be reported.

• The KSFM Journal of Fluid Machinery
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• v.19 no.3
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• pp.33-36
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• 2016

The investigation on the verification of availability simulation for small-scale plant has been carried out. This study focuses on the availability variation induced by number of equipment and iteration with failure density function. The equipment classification of small-scale plant and failure type and the methodologies on Monte-Carlo simulation are established. The availability deviation with programs showed under Max. 1.7% for the case of normal function. This method could be used to availability evaluation of small-scale plant, but calibration of the failure density function is necessary for general application.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.267-274
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• 2016

Sewerage supply in rural community is the important for water quality protection of water system such as river, lake and wetland. And characteristic of small scale wastewater system that have wide range of inflow and concentration in sewage should be considered for stable operation of small scale wastewater treatment plant. In this research, characteristics of flow ratio (flow / designed flow), effect on treatment efficiency of small scale wastewater treatment plant and assessment of optimal flow ratio were conducted through analysis on operation result of 18 small scale wastewater treatment plant in Bong-hwa gun. As a result, flow ratio shows the higher value during summer. However pollutants concentration in sewage was shown the higher concentration during autumn and winter. Treatment of small scale wastewater treatment plant is increased when flow ratio increased, and nutrient treatment efficiency is more sensitive to change of flow ratio than organic compound and suspended solids. According to this research result, it need to be maintained flow ratio 0.8 over value for stable treatment efficiency of small scale wastewater treatment plant.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.06a
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• pp.40-56
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• 1995

During the past two decades, China has seen her great progress in plant biotechnology. Since the Chinese market of herb medicine is huge, while the plant resources are shrinking, particular emphasis has been placed in plant tissue and cell cultures of medicinal plants, this includes fast propagation, protoplast isolation and regeneration, cell suspension cultures and large scale fermentation. To optimize culture conditions for producing secondary compounds in vitro, various media, additives and elicitors have been tested. Successful examples of large scale culture for the secondary metabolite biosynthesis are quite limited : Lithospermum ery throrhizon and Arnebia euchroma for shikonin derivatives, Panax ginseng, P. notoginseng, P. quinquefolium for saponins, and a few other medicinal plants. Recent development of genetic transformation systems of plant cells offered a new approach to in vitro production of secondary compounds. Hairy root induction and cultures, by using Ri-plasmid, have been reported from a number of medicinal plant species, such as Artemisia annua that produces little artemisinin in normal cultured cells, and from Glycyrrhiza uralensis. In the coming five years, Chinese scientists will continue their work on large scale cell cultures of a few of selected plant species, including Taxus spp. and A. annua, for the production of secondary metabolites with medicinal interests, one or two groups of scientists will be engaged in molecular cloning of the key enzymes in plant secondary metabolism.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.432-435
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• 2006

A rapid and mass propagation method for multiple shoots and plant regeneration using bulb scales of Muscari comosum var. plumosum were developed. In vitro different parts of bulb scale as explants were cultured on 11 kinds of MS (1962) media supplemented with various plant growth regulators to induce shoot and callus. A combination of 2.0 mg/L 6-BA and 2.0 mg/L IBA on MS medium was the most favorable and induced the highest production (80%) of shoot formation after 30 days. We also found that the middle part of bulb scale was the best for mass propagation of Muscari comosum var. plumosum of which production could reach 64.4%.

• Progress in Superconductivity and Cryogenics
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• v.20 no.2
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• pp.6-10
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• 2018

Removal of iron oxide scale from feed-water in thermal power plant can improve power generation efficiency. We have proposed a novel scale removal system utilizing High Gradient Magnetic Separation (HGMS). This system can be applied to high temperature and pressure area. We have conducted the lab-scale model experiments using ${\varphi}50mm$ filters and it demonstrated high removal efficiency in HGMS, but scale-up of the system is required toward practical use. In this study, we conducted a large scale mock-up HGMS experiment. We used the superconducting solenoidal magnet with ${\varphi}400mm$ bore and demonstrated that our HGMS system can achieve sufficient scale removal capacity that is required to introduce into both off-line and on-line system.

• Korean Journal of Plant Taxonomy
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• v.49 no.4
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• pp.275-281
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• 2019

One key step in the plant restoration process is the collection of seeds from the field. For the selection of source populations of target plant species for translocation purposes (reintroduction or reinforcements), several approaches are possible. A practical method involves the use of data from reciprocal transplant studies. If no direct data are available, knowledge of population genetics and the phylogeography of the target species can serve as an alternative. In this short review, we briefly propose guidelines for those collecting seeds for plant species restoration based on population genetics theory, focusing on two main questions: Where does the plant material come from and how are sources designated, and how are seeds efficiently collected from local populations? While genetic data on a larger scale (phylogeography and population genetics) are needed to form a reply to the first question, similar data on a smaller scale (fine-scale genetic structures within populations) are necessary to shed light on the second issue.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.4
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• pp.14-21
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• 2015

Korean government plans to establish large-scale horticulture facility complexes using reclaimed land in order to improve the national competitiveness of agriculture at the government level. One of the most significant problems arising from the establishment of those large-scale horticulture facilities is that these facilities still largely depend on a fossil fuel and they require 24 h a day heating during the winter season in order to provide the necessary breeding conditions for greenhouse crops. These facilities show large energy consumption due to the use of coverings with large heat transmission coefficients such as vinyl and glass during heating in the winter season. This study investigated the applicability of waste heat from power plant for large-scale horticulture facilities by evaluating the waste heat water temperature, heat loss and energy saving performance as a function of distance between power plant and greenhouse. As a result, utilizing power plant waste heat can reduce the energy consumption by around 85% compared to the conventional gas boiler, regardless of the distance between power plant and greenhouse.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.486-490
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• 2002

When the fuzzy controller apply to a real plant, We have not excepted result of a satisfactory control by modeling error and lacking information about an plant. In this case, we have to adjust the scale factors for improvement of the control performance and this method need a lot of time and cost for perform a trial and error. In this paper, we proposed the fuzzy controller with the automatic adjustment of scaling factors. It was improve upon the control performance using a adequate scale factor by fuzzy logic and normalizer. As the results of simulation through the second order plant, we confirmed that the proposed the fuzzy controller within the function of automatic scale get a good response compare with the fuzzy controller within the fixed scale factor.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.334-339
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• 2008

Nowadays national research and development fund is continuously increased. And the evaluation on the feasibility of R&D budget investment was carried out. Through this study it was possible that a business feasibility evaluation of large scale research project. Also the benefit of research project about large scale plant(A plant) is $2.67{\sim}3.76$ times of research funds, and the R&D fund pay-back period is $6{\sim}8$ years. And also there is employment effect as $1,200{\sim}2,200$ every year, and $22,000{\sim}35,000$ within 20 years after research project.