• Title/Summary/Keyword: MG paper

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Fabrication and Characteristics of Hot-Film Type Micro-flowsensors integrated with RTD (측온저항체 온도센서가 집적화된 발열저항체형 마이크로 유량센서의 제작 및 특성)

  • 정귀상;홍석우
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.7
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    • pp.612-616
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    • 2000
  • This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the Si membrane in which MgO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$layer. The MgO layer improved adhesion of Pt thin-film to SiO$_2$layer without any chemical reactions to Pt thin-film under high annealing temperatures. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 82 mV at $N_2$flow rate of 2000 sccm/min heating power of 1.2 W. The response time($\tau$:63%) was about 50 msec when input flow was stepinput

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High-temperature superconductors for NMR/MRI magnets:opportunities and challenges

  • Iwasea, Yukikazu;Bascunan, Juan;Hahn, Seung-Yong;Yao, Wejun
    • Progress in Superconductivity and Cryogenics
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    • v.11 no.4
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    • pp.1-7
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    • 2009
  • The unique features of HTS offer Opportunities and challenges to a number of applications. In this paper we focus on NMR and MRI magnets, illustrating them with the NMR/MRI magnets that we are currently and will shortly be engaged: a 1.3GHz NMR magnet, an "annulus" magnet, and an $MgB_2$ whole-body MRI magnet. The opportunities with HTS include: 1) high fields (e.g., 1.3GHz magnet); 2) compactness (annulus magnet); and 3) enhanced stability despite liquid-helium-free operation ($MgB_2$ whole-body MRI magnet). The challenges include: 1) a large screening current Beld detrimental to spatial field homogeneity (e.g., 1.3 GHz magnet); 2) uniformity of critical current density (annulus magnet); and 3) superconducting joints ($MgB_2$ magnet).

Study on the Removal of Fluorescent Whitening Agent for Paper-mill Wastewater Reuse using the Submerged Membrane Bioreactor(SMBR) with Ozone Oxidation Process (제지폐수 재이용을 위한 침지형 생물막 여과와 오존산화공정(SMBR-Ozone Oxidation Process)에 의한 형광증백제 제거에 관한 연구)

  • Choi, Jang-Seung;Shin, Dong-Hun;Ryu, Seung-Han;Lee, Jae-Hun;Ryu, Jae-Young;Shin, Won-Sik;Lee, Seul-Ki;Park, Min-Soo;Lee, Sang Oh
    • Textile Coloration and Finishing
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    • v.30 no.1
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    • pp.51-61
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    • 2018
  • In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

Antibacterial Activities of Medicinal Herbs on Salmonella and E. Coli (생약재가 살모넬라균 및 대장균의 항균에 미치는 효과)

  • Kim, Gye-Yeop;Nam, Ki-Won;Jang, Seung-Joo;Kim, Jung-Eun;Iim, Joung-Soo;Ahn, Byung-Sun;Kwun, Du-Seog;Jung, Hun-Woo;Cho, Kyoung-Oh
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.3
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    • pp.619-623
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    • 2008
  • The purpose of this study was to observe the effects of antibacterial activities on various medicinal herbs. Medicinal herbs used this study was Curcuma aromatica, Scutellaria baicalensis, Angelica dahurica, Platycodon grandiflorum, Houttuynia corolata, and Forsythia saxatilis. To evaluation of the antibacterial effect, we used S. gallinarum(ATCC 9184), S. typhimurium(SAL-13, France), S. enteritidis (ATCC 10376), Escherichia coli(E-62, O78), and S. gallinarum(E. coli). Extracts from each medicinal herbs divided into 100mg/ml, 50 mg/ml, 25 mg/ml, and 12.5 mg/ml. Antibacterial activities achieved by the paper disc test. Antibacterial activities was showed at extracts from Scutellaria baicalensis, Houttuynia corolata, Forsythia saxatilis, but little found at Curcuma aromatica, Angelica dahurica, Platycodon grandiflorum.

Fabrication of Magnesium Alloy Foam Through $TiH_2$ and $CaCO_3$ ($TiH_2$$CaCO_3$를 이용한 마그네슘 합금의 제조)

  • Seo, Chang-Hwan;Seong, Hwan-Goo;Yang, Dong-Hui;Park, Soo-Han;Hur, Bo-Young
    • Journal of Korea Foundry Society
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    • v.26 no.6
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    • pp.267-271
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    • 2006
  • Metal foam is a class of attractive materials, which exhibits unique combinations of physical, mechanical, thermal, electrical and acoustic properties. In particular, it is light and good at absorbing energy, which makes it attractive in automotive and aerospace applications weight is critical. In this paper, the Mg alloy foam was prepared by melt foaming method by addition of calcium as thickening agent, and $TiH_2$ or $CaCO_3$ powder as blowing agent. The macrostructural observation of foamed Mg showed that the pore structures of Mg alloy foam made by $CaCO_3$ as blowing agent were much better than that of foams made by $TiH_2$ as blowing agent. In addition, this paper showed the possible reason of fabrication magnesium alloy foam in proportion to blowing agent and the porosity range was about 40 to 76% as results value.

Islanding detection algorithm for a micro-grid based on the active and reactive power in the time domain (시간영역에서의 유효/무효전력을 이용한 마이크로그리드의 단독운전의 판단 알고리즘)

  • Lee, Young-Gui;Lee, Hye-Won;Kim, Yeon-Hee;Zheng, Tai-Ying;Kang, Yong-Cheol
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.145-146
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    • 2011
  • A micro-grid (MG) is usually interconnected to the main grid through the dedicated line. Immediately after the removal of the grid supply, the MG should be disconnected and remain disconnected until the main grid is re-energized. It should detect islanding condition as soon as it happens to adjust the setting of the protection relays in the MG. This paper proposes an islanding detection algorithm for the MG based on the active and reactive power delivered to the dedicated line in the time domain. The performance of the proposed algorithm is verified under islanding conditions and fault conditions using the PSCAD/EMTDC simulator. The results indicate that the proposed algorithm can discriminate the islanding conditions from the various fault conditions.

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A study on the pinch-off characteristics for Double Cate MOSFET in nuo structure (나노 구조 Double Gate MOSFET의 핀치오프특성에 관한 연구)

  • 고석웅;정학기
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.7
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    • pp.1074-1078
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    • 2002
  • In this paper, we designed double gate(DG) MOSFET structure which has main gate(MG) and two side gates(SG). We have simulated using TCAD simulator U .WOSFET have the main gate length of %m and the side gate length of 70nm. Then, u'e have investigated the pinch-off characteristics, drain voltage is changed from 0V to 1.5V at VMG=1.5V and VSG=3.0V. In spite of the LMG is very small, we have obtained a very good pinch-off characteristics. Therefore, we know that the DG structure is very useful at nano scale.

Study on the Cathodic Protectioin Behavior of Hot Water Boiler by Mg-Alloy Galvanic Anode (Mg 합금유전양긍에 의한 온수보일러의 음극방식거동에 관한 연구)

  • 정기철
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.05a
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    • pp.115-121
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    • 2000
  • As the development of industry water quality of river is going to bad because of waste water of an industrial complex and general home agricultural chemicals exhaust of $SO_3$ and CO gas acid rain and so on. Corrosion damage of boiler factory equipment and so forth occur quickly due to using of the polluted water resulting in increasing leak accident. Especially working life of hot water boiler using the polluted water becomes more short and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection method is suitable for than application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of how water boiler. In tap water and 0.001mol/$\ell$ NaCl solution the characteristics of anodic polarization of Mg-base alloys galvanic anode and tube material is investigated the measurement of cathodic protection potential according to the time elaspsed is carried out.

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Removal of High Strength Nitrogen in Dyeing Wastewater by Decomposition-Air Stripping Process (분해탈기법에 의한 염색폐수 중의 고농도 질소 제거에 관한 연구)

  • Cho, Byeung-Rak
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.3
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    • pp.213-218
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    • 2002
  • Total nitrogen is a major pollutant which mostly causes eutrophication and red tide. Wastewater effluent from printing of cotton-viscose rayon containing high concentrations of total nitrogen can not be effectively treated with a typical biological treatment process. This paper provides a new treatment process and experimental results for the removal of high strength nitrogen from dyeing wastewater. The optimum conditions of air stripping for the removal of total nitrogen include around pH 12, temperature $60^{\circ}C$ with 60 minutes of stripping time. In case of a filtration-air stripping process, an initial level ($500mg/{\ell}$) of total nitrogen was significantly reduced to below $60mg/{\ell}$. Deconite was synthesised for further decomposition of organic nitrogen. Thus, a filtration-decomposition-air stripping process was possibly achieved, by which a high level ($900mg/{\ell}$) of total nitrogen was effectively removed to below $60mg/{\ell}$ P. Finally, a continuous new process for the removal of total nitrogen is proposed and confirmed, based on batch experimental results, and its process validity is further discussed throughout.

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