• Title/Summary/Keyword: AC System

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A Study on Workbench-based Dynamic Service De-sign and Construction of Computational Science Engineering Platform (계산과학공학 플랫폼의 워크벤치 기반 동적 서비스 설계 및 구축에 관한 연구)

  • Kwon, Yejin;Jeon, Inho;Ma, Jin;Lee, Sik;Cho, Kum Won;Seo, Jerry
    • Journal of Internet Computing and Services
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    • v.19 no.3
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    • pp.57-66
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    • 2018
  • EDISON ( EDucation-research Integration through Simulation On the Net) is a web simulation service based on cloud compu-ting. EDISON provides that web service and provide analysis result to users through pre-built infrastructure and various calcu-lation nodes computational science engineering problems that are difficult or impossible to analysis as user's personal resources to users. As a result, a simulation execution environment is provided in a web portal environment so that EDISON can be ac-cessed regardless of a user's device or operating system to perform computational science engineering analysis simulation. The purpose of this research is to design and construct a workbench based real - time dynamic service to provide an integrat-ed user interface to the EDSION system, which is a computational science engineering simulation and analysis platform, which is currently provided to users. We also devised a workbench-based user simulation service environment configuration. That has a user interface that is similar to the computational science engineering simulation software environment used locally. It can configure a dynamic web environment such as various analyzers, preprocessors, and simulation software. In order to provide these web services, the service required by the user is configured in portlet units, and as a result, the simulation service using the workbench is constructed.

Carbon Metabolism and Its Global Regulation in Corynebacterium glutamicum (Corynebacterium glutamicum의 탄소대사 및 총체적 탄소대사 조절)

  • Lee, Jung-Kee
    • Microbiology and Biotechnology Letters
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    • v.38 no.4
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    • pp.349-361
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    • 2010
  • In this review, the current knowledge of the carbon metabolism and global carbon regulation in Corynebacterium glutamicum are summarized. C. gluamicum has phosphotransferase system (PTS) for the utilization of sucrose, glucose, and fructose. C. glutamicum does not show any preference for glucose when various sugars or organic acids are present with glucose, and thus cometabolizes glucose with other sugars or organic acids. The molecular mechanism of global carbon regulation such as carbon catabolite repression (CCR) in C. glutamicum is quite different to that in Gram-negative or low-GC Gram-positive bacteria. GlxR (glyoxylate bypass regulator) in C. glutamicum is the cyclic AMP receptor protein (CRP) homologue of E. coli. GlxR has been reported to regulate genes involved in not only glyoxylate bypass, but also central carbon metabolism and CCR including glycolysis, gluconeogenesis, and tricarboxylic acid (TCA) cycle. Therefore, GlxR has been suggested as a global transcriptional regulator for the regulation of diverse physiological processes as well as carbon metabolism. Adenylate cyclase of C. glutamicum is a membrane protein belonging to class III adenylate cyclases, thus it could possibly be a sensor for some external signal, thereby modulating cAMP level in response to environmental stimuli. In addition to GlxR, three additional transcriptional regulators like RamB, RamA, and SugR are also involved in regulating the expression of many genes of carbon metabolism. Finally, recent approaches for constructing new pathways for the utilization of new carbon sources, and strategies for enhancing amino acid production through genetic modification of carbon metabolism or regulatory network are described.

Phosphate Sorption on Boehmite with Eu(III): P K-edge EXAFS Fingerprinting (뵈마이트 표면의 인산염 및 Eu(III) 수착: 인(P) X-선 흡수분석(EXAFS)에 의한 연구)

  • Yoon, Soh-Joung;Bleam, William F.
    • Economic and Environmental Geology
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    • v.42 no.5
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    • pp.495-500
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    • 2009
  • Actinide sorption to the geological materials can reduce the mobility and bioavailability of radionuclides released to the environment through the development of nuclear weapons and nuclear energy. Under circumneutral pH conditions, actinide sorption can be enhanced by phosphate anions sorbed on oxide mineral surfaces as indicated by the sorption of trivalent lanthanide ions ($Ln^{3+}$), the chemical analog for trivalent actinide ions ($Ac^{3+}$). In this paper, we examined a ternary sorption system of trivalent europium ions ($Eu^{3+}$) sorbed onto boehmite (${\gamma}$-AlOOH) surfaces pre-sorbed with phosphate anions (${PO_4}^{3-}$), using extended X-ray absorption fine structure (EXAFS) spectroscopy. In the Eu-$PO_4$-boehmite ternary sorption system, $EuPO_4$ surface precipitates were formed as implicated by Eu $L_{III}$-edge EXAFS spectroscopy. Phosphorus K-edge EXAFS fingerprinting indicated a bidentate mononuclear surface complex formation of phosphate sorbed on boehmite surfaces as well as $EuPO_4$ surface precipitate formation.

Configuration of Fuel Cell Power Generation System through Power Conversion Device Design (전력변환장치 설계를 통한 연료전지 발전시스템 구성)

  • Yoon, Yongho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.6
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    • pp.129-134
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    • 2021
  • Recently, the demand for electricity is gradually increasing due to the rapid industrial development and the improvement of living standards. In the case of Korea, which is highly dependent on fossil fuels due to such a surge in electricity demand, reduction and freezing of greenhouse gas emissions due to international environmental regulations will immediately lead to a contraction in industrial activities. Accordingly, there are many difficulties in competition with advanced countries that want to link the environment with the country's industrial production activities, and the development of alternative energy as a countermeasure is of great interest around the world. Among these new power generation methods, small-scale power generation facilities with relatively small capacity include photovoltaic generation, wind power generation, and fuel cell generation. Among them, the fuel cell attracts the most attention in consideration of continuous operation, high power generation efficiency, and long-term durability, which are important factors for practical use. Therefore, in this paper, the fuel cell power generation system was researched and constructed by designing the power conversion circuit necessary to finally obtain the AC power used in our daily life by using the DC power generated from the fuel cell as an input.

A Study on Modeling of Leakage Current in ESS Using PSCAD/EMTDC (PSCAD/EMTDC를 이용한 ESS의 누설전류 모델링에 관한 연구)

  • Kim, Ji-Myung;Tae, Dong-Hyun;Lee, Il-Moo;Lim, Geon-Pyo;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.810-818
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    • 2021
  • A leakage current of ESS is classified mainly by the occurrence from a PCS(Power Conditioning System) section and an unbalanced grid current. The reason for the leakage current from the PCS section is a voltage change by IGBT (Insulated Gate Bipolar Transistor) switching and stray capacitance between the IGBT and heatsink. The leakage current caused by the grid unbalanced current flows to the ESS through the neutral line of grid-connected transformer for the ESS with a three limb iron type of Yg-wire connection. This paper proposes a mechanism for the occurrence of leakage current caused by stray capacitance, which is calculated using the heatsink formula, from the aspect of the PCS section and grid unbalance current. Based on the proposed mechanisms, this study presents the modeling of the leakage current occurrence using PSCAD/EMTDC S/W and evaluates the characteristics of leakage currents from the PCS section and grid unbalanced current. From the simulation result, the leakage current has a large influence on the battery side by confirming that the leakage current from the PCS is increased from 7[mA] to 34[mA], and the leakage current from an unbalanced load to battery housing is increased from 3.96[mA] to 10.76[mA] according to the resistance of the housings and the magnitude of the ground resistance.

Effect of Lead Acetate on Pancreatico-biliary Secretion (납(Lead)이 취외분비 기능에 미치는 영향)

  • Sheen, Yhun-Yhong;Kim, Won-Joon
    • The Korean Journal of Pharmacology
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    • v.17 no.1 s.28
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    • pp.17-25
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    • 1981
  • No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of ${\delta}$-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from ${\delta}$-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing $170{\sim}230g$ were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate $(l0{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and EDTA$(each\;10{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and $FeSO_4(each\;l0{\mu}mole/kg/day\;hp)$. The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or $FeSO_4$. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and $FeSO_4$ prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and $FeSO_4$. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.

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Target Advertisement Service using a Viewer's Profile Reasoning (시청자 프로파일 추론 기법을 이용한 표적 광고 서비스)

  • Kim Munjo;Im Jeongyeon;Kang Sanggil;Kim Munchrul;Kang Kyungok
    • Journal of Broadcast Engineering
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    • v.10 no.1 s.26
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    • pp.43-56
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    • 2005
  • In the existing broadcasting environment, it is not easy to serve the bi-directional service between a broadcasting server and a TV audience. In the uni-directional broadcasting environments, almost TV programs are scheduled depending on the viewers' popular watching time, and the advertisement contents in these TV programs are mainly arranged by the popularity and the ages of the audience. The audiences make an effort to sort and select their favorite programs. However, the advertisement programs which support the TV program the audience want are not served to the appropriate audiences efficiently. This randomly provided advertisement contents can occur to the audiences' indifference and avoidance. In this paper, we propose the target advertisement service for the appropriate distribution of the advertisement contents. The proposed target advertisement service estimates the audience's profile without any issuing the private information and provides the target-advertised contents by using his/her estimated profile. For the experimental results, we used the real audiences' TV usage history such as the ages, fonder and time of the programs from AC Neilson Korea. And we show the accuracy of the proposed target advertisement service algorithm. NDS (Normalized Distance Sum) and the Vector correlation method, and implementation of our target advertisement service system.

Preparation of Polymer Gel Electrolyte for EDLCs using P(VdF-co-HFP)/PVP (P(VdF-co-HFP)/PVP를 이용한 EDLC용 고분자 겔 전해질의 제조)

  • Jung, Hyun-Chul;Jang, In-Young;Kang, An-Soo
    • Applied Chemistry for Engineering
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    • v.17 no.3
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    • pp.243-249
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    • 2006
  • Porous polymer gel electrolytes (PGEs) based on poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) as a polymer matrix and polyvinylpyrolidone (PVP) as a pore-forming agent were prepared and electrochemical properties were investigated for an electric double layer capacitor (EDLC) in order to increase a permeability of an electrolyte into the PGE. Propylene carbonate (PC) and ethylene carbonate (EC) as plasticizers, and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a supporting salt for the PGE were used. EDLC unit cells were assembled with the PGE and electrode comprising BP-20 and MSP-20 as activated carbon powders, Super P as a conducting agent, and P(VdF-co-HFP)/PVP as a mixed binder. Ion conductivity of PGEs increased with an increased PVP content and was the best at 7 wt% PVP, whereas electrochemical characteristics such as AC-ESR of unit cell were better in 3 wt%. And electrochemical characteristics of the unit cell with PGE were the best at a 33 : 33 weight ratio of PC to EC. Specific capacitance of a mixed plasticizer system of PE and EC was higher than that of pure PC. Ion conductivity of PGEs with a film thickness of $20{\mu}m$ was higher, but electrochemical characteristics of unit cells were higher for a $50{\mu}m$ membrane thickness. Also, the unit cell has shown the highest capacitance of 31.41 F/g and more stable electrochemical performance when PGE and electrode were hot pressed. Consequently, the optimum composition ratio of PGE for EDLCs was 23 : 66 : 11 wt% such as P(VdF-co-HFP) : PVP = 20 : 3 wt% and PC : EC = 44 : 22 wt%. In this case, $3.17{\times}10^{-3}S/cm$ of ion conductivity was achieved at the $50{\mu}m$ thickness of PGE for EDLCs. And the electrochemical characteristics of unit cells were $2.69{\Omega}$ of DC-ESR, 28 F/g of specific capacitance, and 100% of coulombic efficiency.

Optimization of Human Thrombopoietin Production in Insert Cells Using Baculovirus Expression System (베큘로 바이러스 발현 시스템에 의한 곤충세포에서의 인간 트롬보포이에틴 생산 최적화)

  • 고여욱;손미영;박상규;안혜경;박승국;박명환;양재명
    • KSBB Journal
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    • v.13 no.2
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    • pp.181-186
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    • 1998
  • In order to obtain high-level production of recombinant human thrombopoietin (rhTPO) in insect cell line, HTI-TN-5B1-4 (TN5), conditions for optimal rhTPO expression such as multiplicity of infection (MOI), the cell density at infection, harvesting time and type of culture method as well as growth media were determined. When TN5 cells were cultured as anchorage-dependent state in 60-mm dish, cell density $2\times^6$ cells,MOI of 10 and Garvesting the culture media at 72 hr post-infection wrere the cinditions for highest rh TPO production. High production of rhTPO was also achieved by using EXPRESS FIVE serum free media rather than SF900II serum free media-1. Anchorage-dependent TN5 cells were adapted as a suspension culture when they were grown in the presence of heparin. TN5 cells were successfully cultured at 0.2 L scale in suspension culture without having aggregation. When TN5 cells were cultured as suspension state, cell density of $0.6\times10^6$ cells/mL, MOI of 1 and harvesting the culture media at 72 hr post-infection, gave the highest yield of rhTPO.

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Comparative Compressional Behavior of Zeolite-W in Different Pressure-transmitting Media (제올라이트-W의 압력전달매개체에 따른 체적탄성률 비교 연구)

  • Seoung, Donghoon;Kim, Hyeonsu;Kim, Pyosang;Lee, Yongmoon
    • Korean Journal of Mineralogy and Petrology
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    • v.34 no.3
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    • pp.169-176
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    • 2021
  • This study aimed to fundamentally understand structural changes of zeolite under pressure and in the presence of different pressure-transmitting media (PTM) for application studies such as immobilization of heavy metal cation or CO2 storage using pressure. High-pressure X-ray powder diffraction study was conducted on the zeolite-W (K6.4Al6.5Si25.8O64× 15.3H2O, K-MER) to understand linear compressibility and the bulk moduli in different PTM conditions. Zeolite-w is a synthetic material having the same framework as natural zeolite merlinoite ((K, Ca0.5, Ba0.5, Na)10 Al10Si22O64× 22H2O). The space group of the sample was identified as I4/mmm belonging to the tetragonal crystal system. Water, carbon dioxide, and silicone-oil were used as pressure-transmitting media. The mixture of sample and each PTM was mounted in a diamond anvil cell (DAC) and then pressurized up to 3 GPa with an increment of ca. 0.5 GPa. Pressure-induced changes of powder diffraction patterns were measured using a synchrotron X-ray light source. Lattice constants, and bulk moduli were calculated using the Le-Bail method and the Birch-Murnaghan equation. In all PTM conditions, linear compressibility of c-axis (𝛽c) was 0.006(1) GPa-1 or 0.007(1) GPa-1. On the other hand, the linear compressibility of a(b)-axis (𝛽a) was 0.013(1) GPa-1 in silicone-oil run, which is twice more compressible than the a(b)-axis in water and carbon dioxide runs, 𝛽a = 0.006(1) GPa-1. The bulk moduli were measured as 50(3) GPa, 52(3) GPa, and 29(2) GPa in water, carbon dioxide, and silicone-oil run, respectively. The orthorhombicities of ac-plane in the water, and carbon dioxide runs were comparatively constant, near 0.350~0.353, whereas the value decreased abruptly in the silicone-oil run following formula, y = -0.005(1)x + 0.351(1) by non-penetrating pressure fluid condition.