• 제목/요약/키워드: vacuum concentration

검색결과 658건 처리시간 0.02초

Lily Pollen Growth in vitro and Agrobacterium-mediated GUS Gene Transformation via Vacuum-Infiltration

  • Park, In-Hae;Park, Hee-Sung
    • Journal of Plant Biotechnology
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    • 제4권4호
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    • pp.151-154
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    • 2002
  • Conditions for lily pollen growth in vitro and transformation were optimized. Active pollen tube development was achieved effectively in a medium containing 7% sucrose with pH adjusted to 5.7 at the temperature of 27$^{\circ}C$ for about 16-24 hours. Pollen growth was little impaired by the presence of kanamycin at concentration up to 100 mg/L. Pollen rains near the beginning of germination stage were more reliable for Agrobacterium-mediated GUS DNA transformation via vacuum infiltration lasted for 20-40 minutes. GUS DNA integration and its expression in fully developed pollen tubes could be confirmed by Southern blot hybridization, RT-PCR and histochemical staining.

M/CGS 이중구조를 갖는 박막소자의 온도특성분석 (The Analysis of temperature characteristics on M/CGS thin film devices)

  • 권영호;문형돈;김화영;김영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.826-829
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    • 2003
  • Metal/chalcogenide glass semiconductor(CGS) thin film devices were produced in the vacuum evaporator by the methode of vacuum thermal evaporation. We investigated the influence of the correlations of thickness of metal and CGS upon the concentration of Metal in a CGS thin film. It has shown that M/CGS thin film devices were very sensitive to temperature.

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New Bending System Using a Segmented Vacuum Chuck for Stressed Mirror Polishing of Thin Mirrors

  • Kang, Pilseong;Yang, Ho-Soon
    • Current Optics and Photonics
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    • 제1권6호
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    • pp.618-625
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    • 2017
  • In the present research, a new bending system using a segmented vacuum chuck for Stressed Mirror Polishing (SMP) is developed. SMP is a special fabrication method for thin aspheric mirrors, where simple flat or spherical fabrication is applied while a mirror blank is deflected. Since a mirror blank is usually glued to a bending fixture in the conventional SMP process, there are drawbacks such as long curing time, inconvenience of mirror replacement, risk of mirror breakage, and stress concentration near the glued area. To resolve the drawbacks, a new bending system is designed to effectively hold a mirror blank by vacuum. For the developed bending system, the optimal bending load to achieve the designated mirror deflection is found by finite element analysis and an optimization algorithm. With the measurement results of the deflected mirror surfaces with the optimal bending loads, the feasibility of the developed bending system is investigated. As a result, it is shown that the bending system is appropriate for the SMP process.

Syntheses of Cu-In-Ga-Se/S nano particles and inks for solar cell applications

  • Jung, Duk-Young
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.295-295
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    • 2010
  • Nanoparticles of the compound semiconductor, Cu(In, Ga)Se2 (CIGS), were synthesized in solution under ambient pressure below $100^{\circ}C$ and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption spectroscopy and energy-dispersive X-ray (EDX) analyses. These materials have chalcopyrite crystal structures and the particle sizes less than 100 nm. Synthetic conditions were studied for the crystallized CIGS nanoparticles formation to prevent from side products of Cu2Se, Cu2-xSe, and CuSe etc. The single phase CIGS nanoparticles were applied to coating of thin films photovoltaic cells. The electro deposition of CIGS thin films is also a good non-vacuum technology and under investigation. In aqueous solutions, the different chemical compositions of CIGS thin films were obtained, depending on pH, concentration of starting materials and deposition potentials. The surface morphology of the prepared CIGS thin films depends on the complexing ligands to the solutions during the electrochemical deposition.

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Disperse diazo black D(DBD) photopolymer의 박막 제작과 이의 물리적 특성에 관한 연구 (A manufacture of disperse diaso black D(DBD) photopolymer thin films and its Physical Properties)

  • 정용환;이호식;변대현;김태완
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1333-1335
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    • 1997
  • We have made disperse diazo black D(DBD) thin films using Langmuir-Blodgett(LB) and vacuum-evaporation technique. Physical and optical properties of the films were investigated. Solution was made with a concentration of $10^{-3}mol/{\ell}$ using chloroform. Moving wall apparatus, (NL-LB140S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied UV/visible absorbance spectra and morphology of surface using atomic force microscopy(AFM). Vacuum-evaporated DB D thin films were made at a pressure of $10^{-5}$ torr. The absorption peaks were observed at 200 and 400 nm in the LB films and vacuum-deposited films. We have also studied photoluminescence spectrum of the DBD films.

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진공 환경에서 가열되는 반도체 웨이퍼로의 입자 침착에 관한 수치해석적 연구 (A Numerical Study on Particle Deposition onto a Heated Semiconductor Wafer in Vacuum Environment)

  • 박수빈;유경훈;이건형
    • 한국입자에어로졸학회지
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    • 제14권2호
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    • pp.41-47
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    • 2018
  • Numerical analysis was conducted to characterize particle deposition onto a heated horizontal semiconductor wafer in vacuum environment. In order to calculate the properties of gas surrounding the wafer, the gas was assumed to obey the ideal gas law. Particle transport mechanisms considered in the present study were convection, Brownian diffusion, gravitational settling and thermophoresis. Averaged particle deposition velocities on the upper surface of the wafer were calculated with respect to particle size, based on the numerical results from the particle concentration equation in the Eulerian frame of reference. The deposition velocities were obtained for system pressures of 1000 Pa~1 atm, wafer heating of 0~5 K and particle sizes of $2{\sim}10^4nm$. The present numerical results showed good agreement with the available experimental ones.

Surface Oxidation Effect During high Temperature Vacuum Annealing on the Electrical Conductivity of ZnO thin Films Deposited by ALD

  • Kim, Jin-Yong;Choi, Yong-June;Park, Hyung-Ho
    • 마이크로전자및패키징학회지
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    • 제19권2호
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    • pp.73-78
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    • 2012
  • The chemical, electrical, and optical properties of ZnO and Al-doped ZnO films after high temperature annealing were studied. The resistivity increased significantly after annealing at $600^{\circ}C$ under $10^{-10}$ Torr atmosphere. The mechanism of the resistivity change was explored using photoemission spectroscopy and photoluminescence spectrometer. The results indicated that the amount of oxygen deficient region O-Zn bonds decreased and oxygen vacancy was decreased after the high temperature vacuum annealing. The increase in the resistivity of ZnO and Al-doped ZnO films was resulted from the decrease in carrier concentration due to a decrease in the amount of oxygen deficiency.

Disperse diazo black D(DB-D) photopolymer의 초박막 제작과 이의 물성 및 전기적 특성 연구 (A manufacture of disperse diazo black D(DB-D) photopolymer ultrathin films and its physical and electrical properties[1])

  • 정용환;김태완;변대현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.493-496
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    • 1997
  • We have made disperse diazo black D(DB-D) ultrathin films using Langmur-Blodgett(LB) and vacuum-evaporation technique. Physical and electrical properties of the films were investigated. Solution was made with a concentration of 10$^{-3}$ mol/$\ell$ using chloroform. Moving wall apparatus (NL-LB140 S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied by UV/visible absorbance spectra and morphology of surface using atomic force microscopy. Vacuum-evaporated DB-D think films were made at a pressure of 10$^{-5}$ torrr. The absorption peaks appear at 200 and 40nm in the LB films and vacuum-deposited films. And we have studied photoluminescence spectrum of the DB-D films. Also TGA and DSC properties of the DB-D have been observed and current -voltage characteristics of the DB-D LB films have been measured along the perpendicular direction.

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Effect of Concentration Methods on the Quality of Single and Blended Juice Concentrates

  • Lee, Jun-Ho;Sohn, Kyoung-Suck
    • Preventive Nutrition and Food Science
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    • 제8권3호
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    • pp.225-229
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    • 2003
  • Clarified apple, carrot and orange juices were prepared using ultrafiltration and their single and blend juices were further concentrated using ultrafiltration, freeze-drying, and rotary evaporation. Effect of concentration methods on the quality of concentrated single juices and juice blends was investigated. Turbidity values of samples concentrated by evaporation were significantly higher than those prepared by ultrafiltration and vacuum freezing regardless of juice source (i.e., apple, orange or carrot) or blending (p<0.05). The highest soluble solids contents were obtained for the samples concentrated by evaporation process. Concentrated apple juice contained significantly higher amount of vitamin C and soluble solids than concentrated orange and carrot juices regardless of concentration methods (p<0.05). For blended samples, no direct relationships between blend ratio and total amount of vitamin C were found; however, samples contained more apple juice showed the highest value of soluble solids regardless of concentration methods.

Photovoltaic Characteristics of Low-density Concentration GaAs Solar Cells with/without Anti-reflective Coating

  • Noh, Sam Kyu;Kim, Jong Soo;Kim, Jin Soo;Yu, Jae Su
    • Applied Science and Convergence Technology
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    • 제23권1호
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    • pp.27-33
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    • 2014
  • We have studied photovoltaic characteristics of single-junction GaAs solar cells with/without an $MgF_2/ZnS$ anti-reflective coating (ARC) illuminated by low-density concentration (<10 suns). By the ARC deposition, the short-circuit current density ($J_{SC}$) and the fill factor (FF) are increased by $5mA/cm^2$ and 5% at a standard illumination (1 sun), respectively, and the resulted conversion efficiency is enhanced by 45%. In contrast with the cell with no ARC showing a rapid degradation with increasing concentration power, the efficiency of ARC-deposited cell remains almost constant as ($17.7{\pm}0.3$)% regardless of the concentration. It informs that ARC treatment is very effective in GaAs concentrator solar cells.