• Title/Summary/Keyword: $\textrm{CO}_2$

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A New Technique for Burst Cartridge Detection

  • Hyun, Kyung-Ho
    • Nuclear Engineering and Technology
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    • v.1 no.1
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    • pp.5-16
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    • 1969
  • A design of new burst cartridge detection system for gas-cooled power reactor using a spherical sampling chamber with negative electrode is presented. The results of theoretical calculation indicate that the designed system is feasible for a practical application and sensitive enough to detect a 1 $\textrm{cm}^2$ hole in the fuel clad-ding.

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Preparation and Magnetic Properties of Co-system Amorphous Thin Film by the Sputter method (스파터법에 의한 Co-계 비정질박막의 제작과 자기특성)

  • 임재근;문현욱;서강수;신용진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.11a
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    • pp.190-191
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    • 1994
  • In this paper, We study on the fabrication of amorphous this film of zeromagnetostriction material and the magnetic properties. This films are fabricated by using sputtering method with input power of 400∼607[W], Ar gas pressure of 3∼ 9[mTorr] and target composition of Fe$\sub$4.7/ Co$\sub$74.3/Si$_2$B$\sub$19/. Sample this films with diameter of 14[mm ] and thickness of 27-30[$\mu\textrm{m}$] were obtained through experiments. When we analyzed the magnetic properties before and after annealing with sample thin films, we confirmed that magnetic domain wall amorphous thin films consisted for Neel magnetic domain wall with the width of about 1[$\mu\textrm{m}$].

Fabrication of Heating Actuator Using Cobalt Silicided Thin Films (코발트실리사이드 박막을 이용한 발열 엑츄에이터의 제작)

  • 노영규;장호정
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.234-237
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    • 2002
  • The cobalt silicide was formed OH POly-Si/SiO$_2$/Si Substrates by the E-beam evaporation of Co metal and rapid thermal annealing method for the application of heating actuators. The most stable CoSi$_2$crystal was obtained at temperature of above $700^{\circ}C$ for 20 sec in $N_2$ambient. From the SEM observation, the thickness and diameter of the heating elements were about $1{\mu}{\textrm}{m}$ and $50{\mu}{\textrm}{m}$, respectively. Temperature resistance coefficient of heating elements was found to be about 0.0014($1/^{\circ}C$) with $30~35\Omega$ of resistance.

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A Study on Air Pollution in the Underground Shopping Store of Taejon Area (대전지역 지하상가의 대기오염도에 관한 조사연구)

  • 양천회;류완호;장철현
    • Journal of the Korean Society of Safety
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    • v.9 no.1
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    • pp.134-139
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    • 1994
  • In order to assess the level of atmospheric pollution and to contribute the hearth improvement of residents in Taejon city, the authors were measured the concentration of air pollutants(CO, SO$_2$, NO$_2$, TSP, Pb, Cd, Cr) at three places of the control road in Taejon. The investigative research performed bimonthly from May 1993 to September 1993, and the places were the underground shopping stores of Taejon station, Dongyang department store and provincial goverment areas. The results of statistical analysis are as followings. \circled1CO :0.569~0.966ppm \circled2SO$_2$:0.084~0.170ppm \circled3NO$_2$:0.0045~0.022ppm \circled4TSP:249~299$\mu\textrm{g}$/㎥. \circled5Pb :0.366~1.157$\mu\textrm{g}$/㎥. \circled6Cd:0.016~0.025$\mu\textrm{g}$/㎥. \circled7 Cr : 0.198 ~0.290$\mu\textrm{g}$/㎥. The mean concentration of SO$_2$in Dongyang department store area was 0.17ppm, and it exceeded the ambient air quality standard by 0.02ppm. The concentration of TSP was higher than a standing rule of public hygiene, and it was very near to a standing rule of environmental preservation. The standing rule of indoor air pollution in underground shopping store have two different laws, the public hygiene and the environmental preservation. Therefore, it was difficult to judge what to do in such circumstance. In regarding to the laws, an environmental standard for air pollution in the underground space must unify into the standard of public hygiene.

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Photoluminescent properties of red phosphor (Y,Gd)$_2$O$_3$: Eu for plasma display panel synthesized by homogeneous precipitation method (균일침전법으로 제조한 플라즈마 디스플레이용 적색 형광체 (Y,Gd)$_2$O$_3$: Eu의 발광특성)

  • 김유혁;김좌연
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.6
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    • pp.400-406
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    • 2000
  • The fired Precursor (Y,Gd,Eu)(OH)$CO_3$.$H_2O$$900^{\circ}C$ was used to synthesize the red phosphor $(Y,Gd)_2O_3$: Eu for plasma display panel. Rounded and ~l $\mu\textrm{m}$ diameter phosphor $(Y,Gd)_2O_3$: Eu can be obtained by the reaction of aformentioned powder with a small amount addition of flux at $1350^{\circ}C$ for 2 hours. Emission spectra of these phosphors were measured under excitation wavelength at 254 nm and 147 nm and the optimum concentrations of activator ion were determined at around 15 mo1e % and 10 mole % under these conditions, respectively. $BaCO_3$flux had the best property in emission intensity among the prepared $BaCO_3AlF_3$and $Li_3PO_4$phosphors. The properties of optimized sample were improved in terms of relative luminance and color coordinate comparing with commercial phosphor such as $Y_2O_3$: Eu.

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Effect of Thermal Budget of BPSG flow on the Device Characteristics in Sub-Micron CMOS DRAMs (서브마이크론 CMOS DRAM의 소자 특성에 대한 BPSG Flow 열처리 영향)

  • Lee, Sang-Gyu;Kim, Jeong-Tae;Go, Cheol-Gi
    • Korean Journal of Materials Research
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    • v.1 no.3
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    • pp.132-138
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    • 1991
  • A comparision was made on the influence of BPSG flow temperatures on the electrical properties in submicron CMOS DRAMs containing two BPSG layers. Three different combinations of BPSG flow temperature such as $850^{\circ}C/850^{\circ}C,\;850^{\circ}C/900^{\circ}C,\;and\;900^{\circ}C/900^{\circ}C$ were employed and analyzed in terms of threshold, breakdown and isolation voltage along with sheet resistance and contact resistance. In case of $900^{\circ}C/900^{\circ}C$ flow, the threshold voltage of NMOS was decreased rapidly in channel length less than $0.8\mu\textrm{m}$ with no noticeable change in PMOS and a drastic decrease in breakdown voltages of NMOS and PMOS was observed in channel length less than and equal to $0.7\mu\textrm{m}$ and $0.8\mu\textrm{m}$, respectively. Little changes in threshold and breakdown voltages of NMOS and PMOS, however, were shown down to channel length of $0.6\mu\textrm{m}$ in case of $850^{\circ}C/850^{\circ}C$ flow. The isolation voltage was increased with decreasing BPSG flow temperature. A significant increase in the sheet resistance and contact resistance was noticeable with decreasing BPSG flow temperature from $900^{\circ}C$ to $850^{\circ}C$. All these observations were rationalized in terms of dopant diffusion and activation upon BPSG flow temperature. Some suggestions for improving contact resistance were made.

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전통한우(칡소)의 귀세포를 이용한 핵이식에서 전기융합 조건이 핵이식 수정란의 발달에 미치는 영향

  • 최은주;이호준;김기수;윤종택
    • Proceedings of the KSAR Conference
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    • 2001.03a
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    • pp.67-67
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    • 2001
  • 전기자극은 핵이식 시 수핵난자와 공여핵의 융합을 위해 보편적으로 사용되는 방법이다(Robl, 1999). 그러나 부적절한 전기자극은 수핵난자 세포질에 해를 입히고, 이후의 배발달에 좋지 않은 영향을 준다. 본 실험은 체세포 핵이식을 \circled1 1.9㎸/cm, 20$\mu\textrm{s}$ 2회, \circled22.0㎸/cm, 20$\mu\textrm{s}$ 2회, \circled32.2㎸/cm, 10$\mu\textrm{s}$ 2회, 및 \circled41.9㎸/cm, 30$\mu\textrm{s}$ 2회의 전기자극으로 융합을 실시하여 각 자극 별 융합율과 난자의 lysis율을 비교하고, 배양 후 배반포 발생율을 조사하였다. 공여핵은 칡소의 귀 세포를 10% FBS가 첨가된 DMEM에서 39$^{\circ}C$, 5%$CO_2$의 incubator에서 배양하여 monolayer confluent형성 후 0.5% FBS가 첨가된 DMEM에서 3-4일간 배양 후 trypsin처리하여 제핵된 체외성숙 난자에 핵이식하였다. \circled1,\circled2,\circled3,\circled4의 핵이식 조건을 이용하여 공여핵의 체세포와 수핵란 세포질간의 융합을 유도한 결과, 융합율은 각각 50.7%, 48.1%, 65.5%, 및 33.3%였으며, 수핵난자의 세포질 lysis율은 39.%1, 41.7%, 22.6%,및 52.7%으로 \circled32.2㎸/cm, 10$\mu\textrm{s}$ 2회의 조건에서 융합율이 유의적으로 높았고, 수핵난자의 세포질 lysis율에 있어서도 다른 군에 비하여 낮았다 각각의 핵이식 조건별로 융합한 후 난할율 및 배반포 발생율은 각각 65.7%, 73.5%, 77.2%, 및 53.3%과 47.8%, 52.0%, 49.7%, 및 21.8%로 나타나 난할율 및 배반포 발생율에 있어서 융합조건에 따라 큰 차이는 없었으나 1.9㎸/cm, 30$\mu\textrm{s}$ 2회의 조건이 다른 조건들에 비하여 유의적으로 낮았다. 따라서, 체세포와 수핵란 세포질간의 융합율과 배반포 발생에 미치는 영향은 전압보다는 시간에 더 크게 받음을 알 수 있었으며, 이와 같은 결과에서 융합시 시간을 오래 주는 것보다 전압을 높이는 것이 수핵난자의 세포질에 상해를 줄이고 이후 배반포 발생에 유리할 것으로 사료되었다.

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생쥐 초기 배아에서 Aquaporin 8과 9의 발현에 관한 연구

  • 신현상;계명찬;강수만;이성은;이지원;강한승;김문규
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.68-68
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    • 2003
  • Aquaporin은 막관통 통로 단백질(transmembrane channel protein)로서, 삼투압의 농도구배에 따라 세포막을 가로질러 물분자를 이동시키는 기능을 하고 있다. 포유류 초기배아에서 포배강 형성은 영양외배엽세포에서 $Na^+ / K^+$ATPase에 의한 이온 농도 구배가 형성되면 auqaporin에 의해 물이 포배강으로 유입되면서 이루어진다. 본 연구에서는 생쥐 초기배아에서 반정량적인 역전사 중합효소 연쇄반응 방법(semi-quantitative RT-PCR)과 실시간 역전사 중합효소 연쇄반응 방법(real-time RT-PCR)을 통하여 AQP8과 9의 mRNA발현을 조사하고 다중 면역형광현미경 방법(confocal immunofluorescence microscopy)을 통해 단백질 발현양상을 분석하였다. AQP8 mRNA는 상실기까지 발현되지 않다가 포배기에 이르러 발현되었고 AQP9 mRNA는 수정란에서부터 발현되어 포배기에는 유의할 정도로 증가하였다. 따라서 AQP8 mRNA는 배아유전자가 활성화되어 나타나는 것이고 AQP9 mRNA는 모계유전자 기원임을 알 수 있었다. AQP8 단백질은 상실배 단계까지 발현되지 않다가 포배시기에 영양외배엽세포사이의 접합면에 발현되었고 AQP9 단백질은 상실배 시기에 할구 사이의 인접 부위에서 강하게 발현되었다가 포배시기에는 세포간의 접합면에 약하게 발현하는 경향을 나타내었다. 실시간 역전사 중합효소 연쇄반응 방법으로 조사한 결과 포배에서 물과 글리세롤을 통과시키는 AQP9는 mRNA의 발현양이 AQP8보다 약 4배 정도 많았다. 또한 포배기에 이르러서야 물만을 통과시키는 AQP8의 발현이 나타나는 것을 보아 포배강 형성시 외부에서 영양외배엽을 통해 포배강으로 유입되는 물의 이동(trans- trophectodermal water movements)에 AQP9보다 AQP8이 더 중요하게 관여할 것으로 사료된다., K, Pb, Cd, Cr, Co, Cu, Ni)을 측정하였다. 실험 조건1의 결과로서 각 국의 유아용 일회용 기저귀의 중금속 함량은 거의 유사한 경향을 나타내었으며 Cr, Zn, Pb, Ni, Mn, Mg, Li, K는 detection limit(2 ppm) 이하였고, Cd, Fe, Co, Cu, Ca, Al, Sr는 검출되었지만 기준치 이하였다. 실험 조건2의 결과로서 측정 항목(Cr, Sb, Cd, Pb, Ni, Co, Cu)중 Cr, Cd, Ni, Cu는 detection limit(0.1 ppm) 이하였고, Sb, Pb, Co는 검출되었지만 기준치 이하였다.았다. 4%의 경우에는 8$0^{\circ}C$이하로 온도를 낮추는 것이 좋은 상태를 나타내었다. 이와 같은 결과는 일반적으로 화학적 레팅을 4%, 7%에서한 선행결과와 상당히 다른 결과이다.염 농도가 증가할수록 감소 현상을 보였다.X>, 75BG30은 8.6$\mu\textrm{m}$, 75BG40은 7.02$\mu\textrm{m}$로 나타났다. 따라서 경화제 양에 관계없이 10$\mu\textrm{m}$ 이하로 나타나, 경화제 10$m\ell$만으로 미세한 크기를 얻을 수 있음을 알 수 있다. 젤리 강도 변화에 따른 차이는 300BF는 78.09$\mu\textrm{m}$ 300BG는 56.32$\mu\textrm{m}$로, 75BF나 75BG에 비하여 현저히 증가하여, 젤라틴의 젤리 강도는 캡슐 제조 조건의 주요한 변수임을 알 수 있다.추출물 투여시 혈당강하 및 혈중콜레스테롤 강하가 나타났으며, 상엽복합추출물 투여와 운동을 병행시 이러한 감소 효과가 더 뚜렷하게 나타났다.교육의 적임자로 보는 시각이 비교적 높았고 약 1/2정도는 영양교육에 참여하겠다는 의지를 가지고 있을 뿐만 아니라 실제로 영양지도를

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Genesis and Hydrochemistry of $CO_2$-rich Springs from Kyungpook Province, Korea (경북지역 탄산수의 생성기원과 수리화학적 특성)

  • 정찬호
    • Economic and Environmental Geology
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    • v.35 no.2
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    • pp.121-136
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    • 2002
  • The $CO_2$-rich springs in the Kyungpook Province has been found at 16 locations. Most of the $CO_2$-rich springs outflow along either fault zones or the geologic boundary between Mesozoic granites and their adjacent rocks. The $CO_2$-rich water samples show a high $CO_2$ concentration ( $P_{CO2}0.46 to 5.21 atm), weak acidic pHs, wide electrical conductivity values ranging from 422 to 2,280 $\mu\textrm{S}$/cm, and high re content. They are classified into the ca-HC $O_3$ type in chemical composition.$\delta$$^{18}$ O and $\delta$$^2$H data indicate that $CO_2$-rich water is meteoric origin. The $\delta$$^{13}$ C values (-1.5$\textperthousand$ to -6.1$\textperthousand$ PDB) suggest that dissolved $H_2$C $O_3$$^{0}$ C $O_3$- are mainly derived from a deep-seated $CO_2$ and carbonate minerals. The thermodynamic equilibrium state between $CO_2$-rich water and major minerals, and hydrochemical characteristics indicate that major source minerals determining the chemical composition of $CO_2$-rich water are carbonate minerals, plagioclase, K-feldspar and Fe-oxides. Under high $CO_2$ pressure and the weak acidic condition, most of the $CO_2$-rich water samples are thermodynamically in the dissolution state with respect to albite and carbonate minerals.

Production of Korean Native Calf by In Vitro Maturation, Fertilization, Cultivation and Transfer of Embryos into Holstein Cows (체외성숙, 수정 및 배양된 한우 체외수정란의 유우이식에 의한 산자 생산)

  • 박충생
    • Korean Journal of Animal Reproduction
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    • v.18 no.1
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    • pp.47-54
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    • 1994
  • The objective of this study was to produce Korean native calves following transfer of in vitro matured, fertilized and cultured embryos into Holstein cows. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28$^{\circ}C$ and transported to laboratory within 2 hrs. The oocytes were matured in vitro (IVM) for 24 hrs in TCM-199 supplemented with 35$\mu\textrm{g}$/ml FSH, 10$\mu\textrm{g}$/ml LH, 1$\mu\textrm{g}$/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% CO2 in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (IVC) with bovine oviductal epithelial cells for 7 to 9 days. Late morulae and blastocysts produced in vitro were nonsurgically transferred to recipient cows by unilaterial. Recipients were monitored for estrus and for pegnancy by rectal plapation in 60 days after embryo transfer. One of them was pregnant to term and produced a female weighing 42.5kg at birth.

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