• Title/Summary/Keyword: Al concentration

Search Result 1,827, Processing Time 0.033 seconds

Hydrogen Absorption Characteristics of Al/Pd Film (Al/Pd 박막의 수소 흡수 특성)

  • Cho, Young-Sin
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.17 no.2
    • /
    • pp.234-240
    • /
    • 2006
  • Al film(135.5 nm thick) with Pd film(39.6 nm thick) on the top of it was made by thermal evaporation method. Hydrogen absorption of Al/Pd film was measured by quartz crystal microbalance(QCM) method at room temperature. The sample was activated by hydrogen absorption and desorption cycling at room temperature. Hydrogen was introduced into the film by increasing hydrogen gas pressure step by step up to 640 torr at room temperature. Hydrogen concentration reached up to 25% at $5{\sim}10$ torr. But at high pressure the concentration decreased. This strange tendency was not understood yet. Further study is needed to find out the mechanism of hydrogen absorption in Al in Al/Pd film.

A Study on the Output Power Enhancement of GaAs/AlGaAs Solar Cell using Concentration Method (집광에 의한 GaAs/AlGaAs태양전지의 출력 증대 연구)

  • Lee, Dong-Ho;Kim, Young-Hwan;Song, Jin-Dong;Kim, Seong-Il
    • New & Renewable Energy
    • /
    • v.5 no.3
    • /
    • pp.26-31
    • /
    • 2009
  • Using MBE growth method, GaAs/AlGaAs solar cell structure was grown. Deposited electrodes are Au/Ni/Ge for n-type and Au/Pt/Ti for p-type electrodes were deposited by E-beam evaporator. Indoor light concentrators were devised and fabricated in order to concentrate artificial solar rays. Also mirror and prism and Fresnel lens concentration system with solar simulator were devised and fabricated. Results of solar cell characteristics were measured with shutting system which can control the amount of light. Maximum power density was 2.13 W/$cm^2$ and maximum concentration was 124 sun, when mirror with Fresnel lens was used at $7854\;mm^2$ of shutter hole.

  • PDF

Effect of Al Content Variation on High Temperature Gas Nitriding in 13%Cr-0.16%C Stainless Steel (13%Cr-0.17%C 스테인리스강의 고온 가스질화에 미치는 Al 함량 변화의 영향)

  • Park, B.T.;Kim, J.M.;Kang, H.J.;Kong, J.H.;Kang, C.Y.;Sung, J.H.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.24 no.6
    • /
    • pp.318-326
    • /
    • 2011
  • This study has been performed to investigate the effect of Al addition on High Temperature Gas Nitriding (HTGN) in 13%Cr-0.16%C stainless steel with different Al contents of 0.54%, 1.76% and 2.36%, respectively. HTGN treatment was carried out at $1100^{\circ}C$ for 1 hr, 5 hrs and 10 hrs. Nitrogen-permeated surface layers showed round type carbides of $Cr_{23}C_6$ and needle type nitrides of AlN in the matrix of martensite, representing 600~700 Hv. And the thickness of the surface layer increased with increasing Al content and HTGN treatment time. The inner region that was not permeated nitrogen showed chromium carbides in the mixed phase of martensite and ferrite for the 0.53% Al alloyed steel, however chromium carbides in the matrix of ferrite single phase were shown for the steels with the addition of 1.76%Al and 2.36%Al, representing the hardness of ~200 Hv. During nitrogen permeation from surface to the interior, substitutional elements of Cr, Al and Si moved toward the surface and interstitial element of carbon also moved from interior to the surface. This movement of alloying elements leads high concentration of these elements at the outmost surface, subsequently the lowest peak of substitutional elements were shown in the vicinity of near surface. After showing the lowest peak, the high concentration region of Al and C were formed due to the continuous movement of Al toward the surface. The long discontinuous precipitates of $Cr_{23}C_6$ and AlN were formed along the outmost surface owing to the high concentration of these alloying elements.

Influence of Aluminum Chloride on Growth and Chemical Components of Rice Seedling (염화알루미늄 처리가 벼 유묘생육 및 체내 성분함량에 미치는 영향)

  • 여수갑;김상국;이상철
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.42 no.3
    • /
    • pp.275-280
    • /
    • 1997
  • The experiment was carried out to determine Al tolerance ranges of two rice cultivars(Ilpumbyeo and Hyangmibyeo) during germination and early growth. The amount of 0, 300, 600 and 900ppm Al were treated in the germination media. Plant height and root length of rice cultivars were decreased significantly with Al concentration. The reduction of growth was more remarkable in root than in shoot. Germination rates in all Al concentrations were decreased comparing with untreated control. Two rice cultivars were not different in Al concentrations. As Al concentration was increased, chlorophyll content were decreased. Ca and Mg contents in 300ppm of Al treatment were sharply increased. Free proline contents of both rice cultivars grown at the 300, 600, and 900ppm of Al treatments were increased only in the 3 days after Al treatments.

  • PDF

Effects of Acid Rain Treatment on Height Growth of Several Landscape Tree Species, pH Value and $Al^{3+}$ Concentration in Soil: Comparison after 5 Years [I] (人工酸性雨 處理가 5年後 몇 가지 造景樹種의 樹高生長, 土壤 酸度와 可溶性 알루미늄의 濃度에 미치는 影響 [I])

  • 정용문;우수영;김판기
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.13 no.4
    • /
    • pp.249-256
    • /
    • 1997
  • To identify the long-term influence of acid rain treatment on tree growth, acid rain of various composition (pH 2.0, pH 4.0 and pH 5.6 as control) was applied to several landscape trees for five months (April through August, 1991). Tree height, pH values and $Al^{3+}$ concentration in soil were investigated. Acid rain treatments seemed to promote height growth in the first year (1991), but have become an inhibiting factor over five years. All of coniferous species and most broad-leaved species, except Acer ginnala, showed opposite trends in height responses to acid rain treatments between the first (1991) and last (1996) year. In contrast, Acer ginnala showed similar trends to acid rain treatments in the height growth between 1991 and 1996. This result suggested that Acer ginnala has a characteristic adapability to acid rain stress. pH values of surface soil were lower than those of 30 cm soil depth. This fact suggested that acid rain treatments made surface soil acidic condition. In addition, physiological characteristics (photosynthesis, stomatal condition and biomass) have to be investigated to identify the relationship between long-term effects of $AL^{3+}$ concentration and growth.

  • PDF

Effect of Cu(II) and Al(III) on the Extraction and Separation of Pt(IV) and Pd(II) from Concentrated Hydrochloric Acid Solution with Alamine336 (진한 염산용액에서 구리(II)와 알루미늄(III)이 Alamine336에 의한 백금(IV)과 팔라듐(II)의 추출 및 분리에 미치는 영향)

  • Lee, Manseung;Ahn, Jonggwan;Sun, Panpan
    • Korean Journal of Metals and Materials
    • /
    • v.48 no.2
    • /
    • pp.148-153
    • /
    • 2010
  • The effects of Cu(II) and Al(III) on the extraction and separation of Pt(IV) and Pd(II) have been investigated in a mixed chloride solution using Alamine336 as the extractant. In the HCl concentration range of 1 to 5 M, more than 99% of Pt and Pd could be extracted by Alamine336 from all of the mixed chloride solutions investigated in this study. Lower HCl concentration led to a higher separation factor between Pd and Pt when Alamine336 concentration was constant. Extraction percentage of Cu increased with the increase of HCl concentration, while that of Al was nearly constant at 33% in our experimental range. The optimum conditions to extract Pt and Pd from Cu or Al and the separation factor under these conditions were obtained.

Effect of Doping Amounts of Al2O3 and Discharge Power on the Electrical Properties of ZnO Transparent Conducting Films (ZnO 투명 전도막의 전기적 특성에 미치는 Al2O3 의 도핑 농도 및 방전전력의 효과)

  • Park Min-Woo;Park Kang-Il;Kim Byung-Sub;Lee Se-Jong;Kwak Dong-Joo
    • Korean Journal of Materials Research
    • /
    • v.14 no.5
    • /
    • pp.328-333
    • /
    • 2004
  • Transparent ZnO:Al conductor films for the optoelectronic devices were deposited by using the capacitively coupled DC magnetron sputtering method. The effect of Al doping concentration and discharge power on the electrical and optical properties of the films was studied. The film resistivity of $8.5${\times}$10^{-4}$ $\Omega$-cm was obtained at the discharge power of 40 W with the ZnO target doped with 2 wt% $Al_2$$_O3$. The transmittance of the 840 nm thick film was 91.7% in the visible waves. Increasing doping concentration of 3 wt% $Al_2$$O_3$ in ZnO target results in significant decrease of film resistivity, which may be due to the formation of $Al_2$$O_3$ particles in the as-deposited ZnO:Al film and the reduced ZnO grain sizes. Increasing DC power from 40 to 60 W increases deposition rate by more than 50%, but can induce high defect density in the film, resulting in higher film resistivity.

Production and Characterization of Beta-lactoglobulin/Alginate Nanoemulsion Containing Coenzyme Q10: Impact of Heat Treatment and Alginate Concentrate

  • Lee, Mee-Ryung;Choi, Ha-Neul;Ha, Ho-Kyung;Lee, Won-Jae
    • Food Science of Animal Resources
    • /
    • v.33 no.1
    • /
    • pp.67-74
    • /
    • 2013
  • The aims of this research were to produce oil-in-water ${\beta}$-lactoglobulin/alginate (${\beta}$-lg/Al) nanoemulsions loaded with coenzyme $Q_{10}$ and to investigate the combined effects of heating temperature and alginate concentration on the physicochemical properties and encapsulation efficiency of ${\beta}$-lg/Al nanoemulsions. In ${\beta}$-lg/Al nanoemulsions production, various heating temperatures (60, 65, and $70^{\circ}C$) and alginate concentrations (0, 0.01, 0.03, and 0.05%) were used. A transmission electron microscopy was used to observe morphologies of ${\beta}$-lg/Al nanoemulsions. Droplet size and zeta-potential values of ${\beta}$-lg/Al nanoemulsions and encapsulation efficiency of coenzyme $Q_{10}$ were determined by electrophoretic light scattering spectrophotometer and HPLC, respectively. The spherically shaped ${\beta}$-lg/Al nanoemulsions with the size of 169 to 220 nm were successfully formed. The heat treatments from 60 to $70^{\circ}C$ resulted in a significant (p<0.05) increase in droplet size, polydispersity, zeta-potential value of ${\beta}$-lg/Al nanoemulsions, and encapsulation efficiency of coenzyme $Q_{10}$. As alginate concentration was increased from 0 to 0.05%, there was an increase in the polydispersity index of ${\beta}$-lg/Al nanoemulsions and encapsulation efficiency of coenzyme $Q_{10}$. This study demonstrates that heating temperature and alginate concentration had a major impact on the size, polydispersity, zeta-potential value and encapsulation efficiency of coenzyme $Q_{10}$ in ${\beta}$-lg/Al nanoemulsions.

Critical Ratios of Ca/Al and Mg/Al in Nutrent Solution Limiting Growth of Pinus thunbergii (해송의 생육을 저해하는 Ca/Al 및 Mg/Al의 한계 비율)

  • Lee, Wi-Young;Yang, Jae E.;Park, Chang-Jin;Zhang, Yong-Seon;Ok, Yong-Sik
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.37 no.5
    • /
    • pp.329-335
    • /
    • 2004
  • Acid deposition in forest adjacent to the industrial complexes causes soil acidification resulting in the leaching of cations, decreases of buffering capacity and increases of toxic metal concentrations such as Al, Fe, Mn and Cu in soil solution. Changes of nutrient availability equilibria by acid deposition have been known to retard the growth of pine trees. Objective of this research was to assess the critical ratios of Ca/Al and Mg/Al limiting the growth of Pinus thunbergii in the hydroponic culture. The Ca concentration and Ca/Al ratio in stalks of pine tree were increased as increasing Ca/Al molar ratio in the nutrient solution, but were not changed when the Ca/Al molar ratio was adjusted to greater than 1. Growth of Pinus thunbergii was inhibited at the Ca/Al molar ratio lower than l due to the Ca deficiency. The molar ratios of Ca/Al in the needles of Pinus thunbergii showed the similar tendency with the stalks. This indicated that Ca/Al molar ratio of 1 in the growth media was the critical level limiting the growth of Pinus thunbergii. Concentration of Mg and Mg/Al molar ratios in the stalks of pine tree were increased as increasing Mg/Al molar ratio in nutrient solution. Molar ratios of Mg/Al in the needles were increased as increasing Mg/Al ratios in nutrient solution up to 0.83, which was the critical level limiting the growth of Pinus thunbergii.

Properties of Aluminum Doped Zinc Oxide Thin Film Prepared by Sol-gel Process

  • Yi, Sung-Hak;Kim, Jin-Yeol;Jung, Woo-Gwang
    • Korean Journal of Materials Research
    • /
    • v.20 no.7
    • /
    • pp.351-355
    • /
    • 2010
  • Transparent conducting aluminum-doped ZnO thin films were deposited using a sol-gel process. In this study, the important deposition parameters were investigated thoroughly to determine the appropriate procedures to grow large area thin films with low resistivity and high transparency at low cost for device applications. The doping concentration of aluminum was adjusted in a range from 1 to 4 mol% by controlling the precursor concentration. The annealing temperatures for the pre-heat treatment and post-heat treatment was $250^{\circ}C$ and 400-$600^{\circ}C$, respectively. The SEM images show that Al doped and undoped ZnO films were quite uniform and compact. The XRD pattern shows that the Al doped ZnO film has poorer crystallinity than the undoped films. The crystal quality of Al doped ZnO films was improved with an increase of the annealing temperature to $600^{\circ}C$. Although the structure of the aluminum doped ZnO films did not have a preferred orientation along the (002) plane, these films had high transmittance (> 87%) in the visible region. The absorption edge was observed at approximately 370 nm, and the absorption wavelength showed a blue-shift with increasing doping concentration. The ZnO films annealed at $500^{\circ}C$ showed the lowest resistivity at 1 mol% Al doping.