• Title/Summary/Keyword: AC System

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A Study on the Actual Conditions of Museum Environment for Old Textile Collections -Focused on university Museums- (직물류 유물의 전시 및 보관환경 실태조사-대학박물관을 중심으로-)

  • 배순화
    • Journal of the Korean Society of Costume
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    • v.34
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    • pp.109-120
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    • 1997
  • The conservation of collections in muse-ums is an important aspect for our her-itage. The control of museum environment is a vital factor in the preservation of cool-lections. Inappropriate or fluctuating envi-ronmental conditions can cause irreparable damage to works of arts. In this research we investigated the ac-tual conditions of museum environment for old testiles using questionnaire and mea-sured dye fasing of old textiles on exhibi-tion for 2 months in a university museum the major results are as follows: 1. The control of temperature and rela-tive humidity is a vital factors I the preservation of old textiles in museum generally acceptable temperature and rel-ative humidity standards for old textiles are 18-23$^{\circ}C$ and 50-65% R. H and light level for textiles on exhibition should be limited to 30-50 lux. 2, In university museums the limate control system in exhibition and storage area is in an early stage. Therefore to minimize the deterioration of old textiles the best method of controlling the envi-ronment is to have centralized climate control system in sorage area as well as in display area. 3. Conservator is needed to maintain collections scientifically. Only professional conservator by combining scientific tech-nical and artistic training has the exper-tise needed to maintain the physical in-tegrity of old textiles. In order to solve the inferior environment of museums the staff should recognize the importance of the condition of exhibition and storage. 4. Old textiles are susceptible to damage by light and associated heat. Dyed textiles which have been exhibited under the light without any UV filter were faded notice-ably within two months of exhibition. Light levels for textiles on exhibition should be limited to 30-50 lux. It is de-sirable to use special light source that can absorb UV. and UV filter is also recom-mended to reduce photodegradation of old textiles.

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The Verification of Dosimetric Characteristics of the 3-D Compensator with the Exit Beam Dose Profile (Exit Beam Dose Profile을 이용한 3차원 보상체의 성능확인)

  • 이상훈;이병용;권수일;김종훈;장혜숙
    • Progress in Medical Physics
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    • v.7 no.2
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    • pp.3-17
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    • 1996
  • Dose compensators have been widely used in radiotherapy fields. But, few reliable verification methods have been reported. We have developed the verification method for the evaluation of the effect of dose compensator using exit beam dose profile. The exit beam dose profiles were measured with and without dose compensator. For this purpose X-Omat V films and lead screened cassettes are used and dose distibutions are compared. Phantom data are collected using CT simulator(Picker, AcQ Sim) and compensator information can be obtained from Render Plan 3-D planning System. Aluminum Compensators are generated by computer controlled milling machine. The real dose distribution in the phantom and the exit beam dose profile can be obtained simultaneously with the films in the phantom and the opposite site of the beam. Dose compensations effects for oblique beam, parallel opposing beam and inhomogeneous human phantom can be obtained using above tools. And we could simate those effects with exit beam dose profile using the method that we have developed in this study.

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Studies on Variation of Hygienic Quality for Raw Milk (According to Milk Pricing Structure based on Total Bacterial Count & Somatic Cell Count) (원유의 위생학적 유질변동에 관한 연구 (세균수와 체세포수에 기초한 원유가격제 실시에 따라))

  • 이성모;황현순;손봉환;윤화중
    • Korean Journal of Veterinary Service
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    • v.17 no.3
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    • pp.208-226
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    • 1994
  • From January to December 1993, 3,385 bulk milk samples were collected from 293 herds in Inchon area. Standard plate counts(SPC) and somatic cell counts(SCC) were performed by the method of milk collection, the situation of raising management and monthly. The results obtained are summarized as follows : 1, Annual average SPC and SCC were respectively 638,000 cfu /mm and 647,000 cells /mm. SPC showed an abrupt decrease from January-1,088,000 cfu /mm to December-279,000 cfu /mm, but SCC showed a slow change from January-1,017,000 cells /mm to December -673,000 cells /mm 2. Variation on milk quality(annual average SPC) was shown a wide difference between everyday collection-575,000 cfu /mm and every other day collection-1,243,000 cfu /mm ac-cording to frequency of milk collection from dairy farms. However, there was a little difference In SCC. 3. In the raising scale, average SPC were the lowest in 16~25mi1king cows, and average SCC were the lowest in above 25milking cows. 4. According to types of milking machine, average SPC and SCC of dairy farms that are equipped with pipeline system were respectively 361,000 cfu /mm and 591,000 cells /mm. Those of dairy farms with bucket system were 549,000 cfu /me and 559,000 cells /mm. 5. In the types of management, average SPC an SCC of dairy farms with hired herdsman were 288,000 cfu /mm and 559,000 cells /mm. Those of dairy farms with self-management were 526,000 cfu /mm and 568,000 cells /mm.

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Hydraulic Behaviors of KSTAR PF Coils in Operation

  • Park, S.H.;Chu, Y.;Kim, Y.O.;Yonekawa, H.;Chang, Y.B.;Woo, I.S.;Lee, H.J.;Park, K.R.
    • Progress in Superconductivity and Cryogenics
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    • v.14 no.2
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    • pp.24-27
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    • 2012
  • The superconducting coil system is one of the most important components in Korea Superconducting Tokamak Advanced Research (KSTAR), which has been operated since 2008. $Nb_3Sn$ and NbTi superconductors are being used for cable-in-conduit conductors (CICCs) of the KSTAR toroidal field (TF) and poloidal field (PF) coils. The CICCs are cooled by forced-flow supercritical helium about 4.5 K. The temperature, pressure and mass flow rate of the supercritical helium in the CICCs are interacting with each other during the operation of the coils. The complicate behaviors of the supercritical helium have an effect on the operation and the efficiency of the helium refrigeration system (HRS) by means of, for instance, pressure drop. The hydraulic characteristics of the supercritical helium have been monitored while the TF coils have stably achieved the full current of 35 kA. In other hands, the PF coils have been operated with various pulsed or bipolar mode, so the drastic changes happen in view of hydraulics. The heat load including AC loss on the coils has been analyzed according to the measurement. These activities are important to estimate the temperature margin in various PF operation conditions. In this paper, the latest hydraulic behaviors of PF coils during KSTAR operation are presented.

Characterization of Two Algal Lytic Bacteria Associated with Management of the Cyanobacterium Anabaena flos-aquae

  • Kim, Jeong-Dong;Lee, Choul-Gyun
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.5
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    • pp.382-390
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    • 2006
  • Various microorganisms were isolated from the surface waters and sediments of eutrophic lakes and reservoirs in Korea to enable an investigation of bacteria having algal lytic activities against Anabaena flos-aquae when water blooming occurs and to study enzyme profiles of algal lytic bacteria. Two bacterial strains, AFK-07 and AFK-13, were cultured, characterized and identified as Acinetobacter johnsonii and Sinorhizobium sp., respectively. The A. johnsonii AFK-07 exhibited a high level of degradatory activities against A. flos-aquae, and produced alginase, caseinase, lipase, fucodian hydrolase, and laminarinase. Moreover, many kinds of glycosidase, such as ${\beta}-galactosidase,\;{\beta}-glucosidase,\;{\beta}-glucosaminidase,\;and\; {\beta}-xylosidase$, which hydrolyzed ${\beta}-O-glycosidic$ bonds, were found in cell-free extracts of A. johnsonii AFK-07. Other glycosidases such as ${\alpha}-galactosidase,\;{\alpha}-N-Ac-galactosidase,\;{\alpha}-mannosidase,\; and\;{\alpha}-L-fucosidase$, which cleave ${\alpha}-O-glycosidic$ bonds, were not identified in AFK-07. In the Sinorhizobium sp. AFK-13, the enzymes alginase, amylase, proteinase (caseinase and gelatinase), carboxymethyl-cellulase (CMCase), laminarinase, and lipase were notable. No glycosidase was produced in the AFK-13 strain. Therefore, the enzyme system of A. johnsonii AFK-07 had a more complex mechanism in place to degrade the cyanobacteria cell walls than did the enzyme system of Sinorhizobium sp. AFK-13. The polysaccharides or the peptidoglycans of A. flos-aquae may be hydrolyzed and metabolized to a range of easily utilized monosaccharides or other low molecular weight organic substances by strain AFK-07 of. A. johnsonii, while the products of polysaccharide degradation or peptidoglycans were more likely to be utilized by Sinorhizobium sp. AFK-13. These bacterial interactions may offer an alternative effective approach to controlling the water choking effects of summer blooms affecting our lakes and reservoirs.

Improved instantaneous Following Control Function for High Power Factor PWM Matrix Converter (고역율 PWM 매트릭스 컨버터의 개선된 순시추종 제어함수)

  • Kim, Kwang-Tae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.3
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    • pp.35-43
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    • 2005
  • Matrix converters have been studied for eliminating dc link of conventional converter-inverter system, and various undulation strategy have been proposed. Therefore, matrix converter have no energy storage component except for small ac later for the elimination of switching ripple, and can be made compact and highly reliable compare with the do link inverter system. Matrix converter, however, directly connected the input and the output terminals by bidirectional static switch. As a result if the input voltage are asymmetrical, and contain harmonics, the influence of the distortions directly appear on the output terminal. This problem is a major obstacle to the matrix converter. A new control method using average comparison strategy have been proposed in this paper. This control method realizes sinusoidal input and output current unity input displacement factor regardless of load power factor. Moreover, compensation of the asymmetrical and/or harmonic containing input voltage is automatically realized, and calculation time of control function is reduced.

Hexose Uptake and Kinetic Properties of the Endogenous Sugar Transporter(s) in Spodoptera frugiperda Clone 21-AE Cells

  • Lee Chong-Kee
    • Biomedical Science Letters
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    • v.11 no.3
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    • pp.327-332
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    • 2005
  • Sf21 cells become popular as the host permissive cell line to support the baculovirus AcNPV replication and protein synthesis. The cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, unlike human glucose transporters, very little is known about the characteristics of the endogenoussugar transporter(s) in Sf21 cells. Thus, some kinetic properties of the sugar transport system were investigated, involving the uptake of 2-deoxy-D-glucose (2dG1c). In order to obtain a true measure of the initial rate of uptake, the uptake of $[^3H]2dGlc$ from both low $(100{\mu}M)$ and high (10 mM) extracellular concentrations was measured over periods ranging from 30 sec to30 min. The data obtained indicated that the uptake was linear for at least 2 min at both concentrations, suggesting that measurements made over a 1min time course would reflect initial rates of the jexpse uptake. To determine $K_m\;and\;V_{max}$ of the endogenous glucose transporter(s) in Sf21 cells, the uptake of 2dG1c was measured over a range of substrate concentrations $(50{\mu}M\~10mM)$ 2dG1c uptake by the Sf21 cells appeared to involve both saturable and non-saturable (or very low affinity) components. A saturable transport system for 2dG1c was relatively high, the $K_m$ value for uptake being < 0.45 mM. The $V_{max}$ value obtained for 2dG1c transport in the Sf21 cells was about 9.7-folds higher than that reported for Chinese hamster ovary cells, which contain a GLUT1 homologue. Thus, it appeared that the transport activity of the Sf21 cells was very high. In addition, the Sf21 glucose transporter was found to have very low affinity for cytochalasin B, a potent inhibitor of human erythrocyte glucose transporter

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Development of TASS Code for Non-LOCA Safety Analysis Licensing Application (Non-LOCA 인허가 해석용 TASS 코드의 개발)

  • Yoon, Han-Young;Auh, Geun-Sun;Kim, Hee-Cheol;Kim, Joon-Sung;Park, Jae-Don
    • Nuclear Engineering and Technology
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    • v.27 no.1
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    • pp.53-66
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    • 1995
  • Since the current licensed system codes for Non-LOCA safety analysis are applicable only for a specific type PWR, it is necessary to develope a new system analysis code applicable for all apes of PWRs. As a R&D program, KAERI is developing TASS code as an interactive and faster-than-real-time code for the NSSS transient simulation of both CE and Westinghouse plane. It is flexible tool for PWR analysis which gives the user complete control over the simulation through convenient input and output options. In this paper the code applicability to Westinghouse ape plants was verified by comparing the TASS prediction to plant data of loss of AC power and loss of load transients, and comparing to the prediction of RELAP5/MOD3 for feedline break, locked rotor, steam generator tube rupture and steam line break accidents.

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Effects of Sagan-tang and individual herbs on COPD Mice Model (만성폐쇄성폐질환 동물모델에 대한 射干湯 및 구성약물의 효과)

  • Han, Jong-Min;Yang, Won-Kyung;Kim, Seung-Hyeong;Park, Yang-Chun
    • Herbal Formula Science
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    • v.23 no.2
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    • pp.171-187
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    • 2015
  • Objective This study aimed to evaluate the effects of Sagan-tang (SGT) on COPD mouse model. Methods The study was carried out by two ways (in vitro, in vivo). In vitro RAW264.7 cells (mouse macrophage) were used and analysed by flow cytometry, ELISA, Western blot. In vivo LPS and CSS challenged mice were used and its BALF had been analysed by cytospin image, FACS, ELISA, lung tissue by real-time PCR. Results In vitro, SGT maintained 80-100% rate of viablilty on 10 ~ 500 ㎍/㎖ concentration. In ELISA analysis with RAW264.7 cells, SGT significantly decreased NO over 30 ㎍/㎖. In flow cytometry, SGT 100 ㎍/㎖ dosage group displayed a tendency for decrease ROS. In Western blot analysis, SGT 100 ㎍/㎖ dosage group decreased NF-κB. In ELISA analysis, SGT significantly decreased TNF-α, IL-6 over 200 ㎍/㎖. In vivo SGT 200 ㎎/㎏ dosage group, application of SGT significantly decreased increase of neutrophils, TNF-α, IL-6 in BALF, muc5AC, TGF-β, TNF-α, expression of mRNA in lung tissue and histological lung injury. Conclusion This Study suggests usability of SGT for COPD patients by controlling lung tissue injury.

Module Design and Performance Evaluation of Surge Arrester for Loading In Railway Rolling Stock (전철 탑재형 피뢰기의 모듈설계 및 성능평가기술)

  • Cho, H.G.;Kim, S.S.;Han, S.W.;Lee, U.Y.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2038-2040
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    • 2000
  • The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and subway are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrestor and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise. etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

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