• Journal of the Korean housing association
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• v.24 no.4
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• pp.53-60
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• 2013

Apartments amount to 58.3%, the highest proportion of domestic housing types. These apartments' lifespan (approximately 27 years) are one-third of the developed countries' housing lifespan due to the property developers and mass production. It is significantly short-cycle period considering the original physical lifespan of the apartment housing are 60 years. It has caused economic loss and environmental degradation. In recent years, research and development for the long life of the apartment housing has been actively performed, but it is limited on reconstruction and new construction. Reconstruction of existing a number of high-rise apartments is difficult owing to restrictions on the floor area ratio allowing for 40 years limit of decay resistance after the completion. Improving lifespan of the building has recently begun to receive attention as an alternative to remodeling. However, These sort of remodeling techniques tend to be focused on technology developed for the physical life extension. That means developing the techniques about dwelling-unit environment for residents satisfaction are required as well as improving physical construction. The purpose of this study is to propose and verify the Participatory Design Technique which can help the residents as the active participation in the design decision-making process.

• BMB Reports
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• v.33 no.5
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• pp.385-390
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• 2000

Overwintering plants should survive the various biotic and abiotic stresses that occur during winter. Previous studies indicated that active oxygen species are involved in freezing, dehydration, anoxia and pathogen infections. As the importance of the events that occur in the intercellular compartment became apparent in disease resistance, we examined the nature of intercellular antioxidant enzymes in order to access their possible involvement in the winter hardiness of barley. The levels of intercellular peroxidase, catalase, and SOD activities on the unit protein basis were 394, 18, and 9% of those of cellular activities, respectively. Major intercellular peroxidase isoforms consisted of four neutrals and four basic forms; whereas major cellular isoforms were two basic forms. Out of the two major catalase isoforms a higher molecular weight form was predominantly abundant in both cellular and intercellular compartments. Among the five major cellular SOD isoforms, three were also present in the intercellular compartment. The presence of substantial amounts of intercellular antioxidant enzymes in overwintering barley leaves may suggest the involvement of these enzymes in the tolerance mechanism to the various stresses that occur during winter.

• Textile Coloration and Finishing
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• v.16 no.4
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• pp.1-9
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• 2004

In recent, development of nano fiber has been one of the most active subjects in the world. Nano fiber is defined as a ultra fine yarn with a diameter unit of $10-100\times10^{-9}meter$, which is possible to be produced by an electro-spinning technology. In this study, physical characteristics and dyeing properties of nylon 66 nano fiber were investigated. Nylon 66 nano fiber was dyed with levelling type acid dyes. X-ray diffraction method and DSC analysis were used for the measurement of the degree of crystallization. Analysis of amino end groups was also performed in order to examine a relationship between number of amino groups and its dyeing property as well as water absorption behavior. The maximum exhaustion % of dyes and dyeing rate under various dyeing conditions, such as dyeing temperature and pH in dye bath, along with build-up properties for 2 acid dyes were evaluated. It was found that the degree of crystallization of nano fiber was smaller than that of regular fiber, and amino end groups of nano fiber were less than regular fiber. Half dyeing time of nano fiber was shorter than regular fiber because of the bigger specific surface area. Effect of pH on exhaustion % was small in case of nano fiber. Exhaustion of nano fiber increased with higher concentration of dye.

• Tribology and Lubricants
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• v.10 no.2
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• pp.43-50
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• 1994

The hydrodynamic bearing is accepted in many rotating systems because it has a large load carrying capacity. But the anisotropic pressure distribution of the bearing can arise the unstable vibration phenomenon over a certain speed. The magnetic bearing is an active element so that the unstable phenomenon of the hydrodynamic bearing, which is induced by the anisotropic support pressure of the oil film, can be controlled if the control algorithm and the controller gains are chosen appropriately. In this study, we investigate the stabilization method of the hydrodynamic bearing system composing the hybrid bearing which is the single unit of hydrodynamic bearing and magnetic bearing. The load carrying conditions of the hybrid bearing is modelled by the sum of the stiffness and damping coefficients of the hydrodynamic and the magnetic bearings in each direction. The dynamics of the rotor is analyzed by the Finite Element Method and the stability limit is determined by the eigenvalues of the hybrid bearings and shaft system. The eigenvalue study of the system shows that the stability limit of the hybrid bearing is increased compared to that of the hydrodynamic bearing. A Small increment of the stiffness and damping coefficient of the hybrid bearings by the magnetic actuators can increase the stability limit of the system. In this paper we tried to show the design references of the hybrid bearings by using the nondimensional bearing parameters. The analysis results show the possibilities of the stability limit increment of the hydrodynamic bearing system by combining the magnetic bearing.

• Journal of environmental and Sanitary engineering
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• v.11 no.2
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• pp.43-52
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• 1996

Using rotating biological contactor(RBC) with artificial endogenous stage and aerobic fixed biofilm reactor(AFBR), organic material removal and biological nitrification of piggery wastewater has been studied at a pilot plant. RBC was operated in the endogenous phase at a interval of every 25 days. The concentration of COD, BOD and TKN in influent wastewater were from 2,940 to 3,800 mg/L, from 1,190 to 1,850 mg/L and from 486 to 754 mg/L respectively. The maximum active biomass content represented as VSS per unit aera was $2.0mg/cm$^{2}$ and biofilm dry density of $17mg/cm^{3}$ was observed at biofilm thickness of $900{\;}{\mu}m$. It was observed that the pilot scale RBC/AFBR process exhibited 72 percentage to 93 percentage of BOD removal, In order to obtain more than 90 percentage of BOD removal, the organic loading rate to the RBC/AFBR process should be maintained less than $0.09{\;}m^{3}/m^{2}{\cdot}day(125.9g{;\}BOD/m^{3}{\cdot}d$. The TKN removal efficiencies was from 45.5 to 90.9 percentage according to vary influent loading rate, It was estimated that the RBC/AFBR process consumed approximately 6.2 mg/L(as $CaCO_{3}$) of alkalinity per 1 mg/L of $NH_{3}$-N oxidized as the nitrification took piace.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.191-195
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• 2007

In this study, we estimated the performance of PEMFC's unit cell as changing operating temperature in different inlet humidity condition at cathode side but anode dry, and tried to match experimental results with 1-dimensional simulation. We used $Nafion^{\circledR}112$ membrane and a self-manufactured PEMFC with active area of $25cm^{2}$ was used in this study. The range of operating temperature was $40{\sim}70^{\circ}C$ and oxygen through bubbled humidity chamber was supplied $0{\sim}80$% humidity condition as changing water temperature in humidity chamber. For figuring out governing equations, represent water contents in electrolyte membrane, the linear forward difference method was applied about time progress and quadratic central difference method was used about space progress. It was assumed that pressure terms were linearly changed due to thin electrolyte membrane. In low operating temperature condition, $40{\sim}60^{\circ}C$, increasing temperature rarely effected cell performance but we can see performance drop at $70^{\circ}C$. By modifying Henrry's constant and/or diffusion coefficient, the modified one-dimensional model was accomplished for calculation.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1055-1060
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• 2001

Experimental data for the on-line estimation of cell concentration and growth rate are presented. For this purpose, we utilized the on-line calculation of the oxygen uptake rate (OUR), which was derived from a liquid phase dynamic mass balance for the oxygen during the active growth phase in cyclosporin A (CyA) fermentation. The cell yield coefficient, based on the oxygen $(Y_{x/o})$for both suspended and immobilized cells of Tolypocladium inflatum, was estimated as $1.9 gDCW/gO_2$ from a very good linear correlation between the cell mass produced and the total oxygen consumed. The calculated yield showed a good agreement with the value of $(Y_{x/o})$ generated from the correlation between the cell growth rate and the oxygen uptake rate. In addition, further experimental data are given, which were also applied to determine the specific oxygen uptake rate of T. inflatum cells during the exponential phase of CyA fermentation. A theoretical basis for the analysis of these fermentation parameters is also provided.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.78-84
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• 2016

The FHX (Forced-draft sodium-to-air Heat Exchanger) employed in the ADHRS (active decay heat removal system) is a shell-and-tube type counter-current flow heat exchanger with M-shape finned-tube arrangement. Liquid sodium flows inside the heat transfer tubes and atmospheric air flows over the finned tubes. The unit is placed in the upper region of the reactor building and has function of dumping the system heat load into the final heat sink, i.e., the atmosphere. Heat is transmitted from the primary cold sodium pool into the ADHRS sodium loop via DHX (decay heat exchanger), and a direct heat exchange occurs between the tube-side sodium and the shell-side air through the FHX tube wall. This paper describes the DHRS and the structural design of the FHX.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.2
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• pp.9-21
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• 2011

This study aims to examine and research the characteristics of apartment landscape at the street from a view that apartments are the major element of a cityscape and many apartments form a street today. Then, the subjects of this study were three sections consisting of streets in Namak New Town and the results were as follows. A streetscape is necessary to have identity under the unity(context) of parts which orient to "one as a whole". However, the subject apartments were not united(contextual) in layouts, roofs, and walls, whereas their facades appeared too united(contextual). Accordingly, to make a united(contextual) streetscape, the wall located in a boundary(a buffer zone) with public space which consists of a streetscape, building layout, building height, and roof forms need a design guideline which can have unity as a whole to connect with architectural design. On the other hand, the facade which was found too uniform should have a more active design guideline to elicit identity at unity.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.13-19
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• 1985

Acc I endonuclease has been isolated from 300g (wet weight) cells of Acinetobacter calcoaceticus. The cells were broken by using French press at 20, 000p.s.i. After ammonium sulfate fractionation, the enzyme was further purified by heparin agarose, DEAE-sephades, Affi.-gel Blue, phosphocellulose, and hydroxylapatite column chromatography. The purified Acc I endonudlease has a single polypeptide species and its subunit molecular weight was 45,000 ${\pm}$ 1,000 daltons as judged by 10% SDS-polyacrylamide gel electrophoresis. The isolated enzyme was essentially free of contaminating nucleases as judged by homochromatography by using a $^{32}P-labeled$ oligonucleotide. The enzyme showed maximum activity at pH values between 8.0 and 11.0 and in the presence of $MgCl_2$. Acc I endonuclease was maximally active in the absence of NaCl and was completely inhibited at 200 mM NaCl.