• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.47-52
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• 2010

This study was carried out to investigate the availability of covering material used for raising seedlings in the rice nursery bed. The pre-germinated seeds of a rice cultivar 'Chilbo' were sown into seedling tray ($60{\times}30{\times}2.5cm$) on 20th April and 3rd May 2010. Polypropylene spunbonded fabric (PSF) and lagging were used for covering materials in rice nursery bed. The growth characteristics of seedlings were evaluated at 8, 15 and 25 days after sowing (DAS) in the nursery beds covered with PSF and lagging, respectively. The plant height of 8-day old seedlings grown in lagging nursery bed was longer by 2cm than those in PSF nursery bed when the seeds were sown on 20th April, but seedling quality grown in lagging nursery bed was poor compared with that in PSF nursery bed. The growth characteristics of 15-day old seedlings were similar to that of 8-day old seedlings. The plant height of 8, 15 and 25-day old seedlings grown in lagging nursery was longer than those in PSF nursery when the seeds were sown on 3rd May. The seedling quality grown in PSF nursery was better than that in lagging nursery. The seedlings grown in PSF nursery have more leaves and better seedling quality compared with that of lagging nursery. The seedling quality was remarkably decreased with the increase of nursery period in lagging bed but seedlings quality were recovered at 5 days after hardening treatment by removing the lagging.

• Journal of agriculture & life science
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• v.43 no.2
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• pp.47-53
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• 2009

This research is intended to study the induction net of chrysanthemum used in its greenhouse and requiring lots of time for manual work and review the structural safety of a bed and existing greenhouses after designing the bed of a net which increases cropping period by sharply reducing the time of work and provides the bed of induction nets for cultivating chrysanthemum with its existing and new greenhouse. The review of sectional and biodynamic properties in 15 kinds of materials has revealed that the pipes of ${\phi}38.1{\times}1.7t$and ${\phi}38.1{\times}2.0t$ didn't exceed stress ratio but did 10mm drooping allowance. For this reason, the pipe of ${\phi}48.1{\times}1.5t$ net both stress ratio and drooping allowance. For the safety, the middle chamber should be designed into Truss type owing to bed load, wind load, and snow load when the bed of an induction net is installed in the middle chamber. When installing the middle chamber with a truss type, the greenhouse of chrysanthemum in Geochang area needs proper reinforcements because the stress in colullllls and wind proof walls exceeds stress allowance regardless of the installation of a bed.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.512-517
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• 2005

To establish the economical cultivation method of Gastrodia elata Blume by controlling the shading rate and the mixing ratio of recycling spawn bed logs, a serial experiment was carried out. When G. elata was grown in the field with no shading, the yield of spawn tuber was higher than that of tuber of G. elata. The yield of G. elata was high in the rainproof green house covered with one layer of $95\%$ shading net, in the rainproof green house covered with two layers of $95\%$ shading net, and in the field with no shading, in that order. In the case of mixing ratio of recycling spawn bed logs, the yield was high in the fresh logs, in the mixing ratio of 2:1, and the ratio of 1:1, in that order. The income of the rainproof green house covered with one layer of $ 95\%$ shading net which brought the best yield was $81\%$ in the mixing ratio of 2:1 over the fresh logs.

• Journal of the Korean Professional Engineers Association
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• v.46 no.2
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• pp.44-50
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• 2013

The treatment of city life wastes is headache problem. Now, only small portion of burnable wastes is burnt at modern process incinerators, the other large portion is buried in the soil by landfill method. The burnable wastes will be increased year by year. The dioxin, the cancer-causing agent, produced by incineration of wastes influences harmful effect to national human health. The new idea of burnable wastes treatment is using the city life wastes as auxiliary fuel of fluidizing bed combustion boiler of large scale coal-fired power plant. The dioxin-free treatment of burnable wastes is sucessfully achieved by burning the wastes, in flyash storm at fluidizing bed combustion boiler.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.525-529
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• 1990

Plant cell cultures of Lithospermum erythrorhizon were performed in stirred tank and packed-bed reactors with in situ extraction by n-hexadecane. The specific shikonin production and volumetric shikonin productivity of stirred tank reactor reached 1.5 mg shikoninlg cell and 400$\mu g$ shikonin/(L.day), respectively. In packed-bed reactor with calcium alginate-immobilized cells specific shikonin production and volumetric productivity reached 2.0 mg shikoninlg cell and 2857$\mu g$ shikonin/(L.day), which were 1.3 and 7.1 times higher than those of stirred tank reactor, respectively. The higher shikonin production and productivity of packed-bed reactor seemed to be due to high cell loading capacity of calcium alginate immobilized cells in packed-bed reactor and improved cell-cell contact.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.54-60
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• 2002

To obtain the breakthrough characteristics for the design of fixed bed adsorption plant, adsorption experiment on granular activated carbon was performed with tharonil in the fixed bed. The pore diffusivity and surface diffusivity of tharonil estimated by the concentration-time curve and adsorption isotherm were $D_s=2.825{\times}10^{-9}cm^2/s,\;D_p=1.26{\times}10^{-5}cm^2/s$, respectively. From comparison of the pore diffusivity and surface diffusivity, it was found that surface diffusion was controlling step for intrapaticle diffusion. The breakthrough curve predicted by constant pattern-linear driving force model were shown to agree with the experimental results. The surface diffusivity and film mass transfer coefficient had no effect on the theoretical breakthrough curve but the adsorption isotherm had fairly influence on it. Appearance time of breakthrough curve is faster with the increase flow rate and inflow concentration of liquid. The utility of granular activated carbon is enhanced with the increase of bed height and with the decrease of inflow rate.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.652-656
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• 2004

Both surface wash and backwash are considered as one of the most important methods that can improve the filtration efficiency in the existing water treatment plant. This study has mainly focused on the improvement of filtering efficiency by controlling surface wash and backwash time, and water level before backwash (when drained up to the trough, when drained up to 10 cm above filter bed, and when drained below 10 cm filter bed). Filtration efficiency was shown a little bit of differences depending on the operating conditions like surface wash injection pressure, the distance control between filter bed and the facility, and the types of surface wash. When the water level before backwash was reached up to 10 cm below filter bed after draining, however, the filtration velocity and the turbidity removal efficiency in the filter bed was improved. When the surface wash followed by backwash is longer, it showed a similar result. Because the proper adjustment of surface washing time makes filtration efficiency higher, therefore, it is necessary to set up the backwash time moderately.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.561-564
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• 2005

Gasification has been regarded as a very important technology to decrease environmental pollution and to obtain higher efficiency. The gasification process converts carbon containing feedstock into a synthesis gas, composed primarily of CO and $H_2$. And the synthesis gas can be used as a source for power generation or chemical material production. Through more than nine years, IAE developed and upgraded several gasification/melting pilot plant system, and obtained a good quality synthesis gas. This paper illustrates the gasification characteristics and operation results of two 3 ton/day synthesis gas production facilities. One is entrained-bed slagging type coal gasifier system which is normally operated in the temperature range of $1,400\~1,450^{\circ}C,\;8\~10$ bar pressure. And the other is fixed-bed type gasification/melting furnace system using MSW and industrial wastes as a feedstock.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.199-203
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• 2002

In this paper, the effects of water contents on combustion characteristics of paper sludge and capacity of fluidized bed combustor(FBC) were investigated using 0.26m diameter, 1.75m height pilot-plant scale combustor. Combustion tests of paper sludge containing water contents between 40wt% and 50wt% were performed. The temperature and emission variation, the pressure inside combustor were measured to monitor the fluidization quality. The experimental results showed that 30kg/hr feeding rate of sludge containing water up to 45wt% was preferable for this system. Sludge loading rate, heat release rate were calculated from experimental data as major parameters showing FBC capacity. Comparsion with sludge loading rate from other source was also performed

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.225-226
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• 2017

Recently, there has been a growing interest in the development of non-sintered binder to reduce CO2 emissions from the cement clinker manufacturing process and a number of studies have been conducted on fly ashes as an industrial by-product. However, in order to utilize fly ashes as a non-sintered binder, it is necessary to solve problems such as safety issues and economical efficiency due to use of an alkali activator. This study evaluates the material properties and compressive strength characteristics of three types of circulating fluidized bed boiler ashes. As a result, it was confirmed that the characteristics of each binder vary depending on the location of the power plant and the types of raw materials. In addition, it has been confirmed that the fluidized bed boiler ash shows a high compressive strength and can be used sufficiently as an non-sintered binder.