• Title/Summary/Keyword: Ion composition

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The Influence of Surface-modified ITO by Ion Beam Irradation on the Organic EL Performances (이온빔으로 조사된 ITO 전극 표면이 유기 EL 소자성능에 미치는 영향)

  • Oh, Jae-young;Joo, Jin-soo;Lee, Chun-An;Park, Byung-Gook;Kim, Dong-hwan
    • Korean Journal of Materials Research
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    • v.13 no.3
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    • pp.191-194
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    • 2003
  • The influence of on ion beam irradiation to the indium tin oxide (ITO) substrate on the performance of the organic light-emitting diodes (OLEDs) was studied. ITO films were used as the transparent anode of OLEDs with poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) as a hole-injection/transport layer. Oxygen and argon plasma treatment of ITO resulted in a change in the work function and the chemical composition. For plasma treated ITO anodes, the device efficiency clearly correlated with the value of the work function. We also discussed the implications of our experimental study in relation to the modification of the ITO surface composition, transmittance, reflectance, and water contact angle (WCA).

The Proton Contamination Problem of RBSPICE's electron data during March 1, 2013 storm event

  • Kim, Hang-Pyo;Hwang, Junga;Choi, Eunjin;Park, Jong-Seon;Park, Young-Deuk
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.95.1-95.1
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    • 2013
  • The RBSPICE (Radiation Belt Storm Probes Ion Composition Experiment) is one of five instrument suites onboard the twin Van Allan Probes (or Radiation Belt Storm Probes; RBSP), launched August 30, 2012 by NASA. One of science targets of RBSPICE instrument is to determine "how changes in that ring current affect the creation, acceleration, and loss of radiation belt particles?". For that purpose, it measures ions and electrons simultaneously. Ion's energy range is from ~20 keV to ~1 MeV and electron's energy channel is from ~35 keV to 1 MeV in order to provide supplementary information about the radiation belts. In this paper, we investigate a reliability of the electron flux measured from the RBSPICE by comparing with ECT (The Energetic Particle, Composition and Thermal Plasma Suite) data. We found there is a critical proton contamination problem in the electron channels of ~ 1MeV of RBSPICE observations during one moderate storm event of Sym H ~ -76 nT on March 1, 2013.

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Structural and Magnetic Properties of the Substituted YIG System (치환된 YIG계의 구조적 및 자기적 특성)

  • Choi, Seung-Han;Lee, Young-Bae
    • Korean Journal of Materials Research
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    • v.13 no.1
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    • pp.48-52
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    • 2003
  • The substituted yttrium iron garnet systems $Y_{ 3-x}$/Gd$_{x}$X$0.2_{0.2}$ $Fe_{4.8}$ $O _{12}$ (x = 0.2, 0.4, 0.6) have been investigated by means of X-ray diffraction, Mossbauer spectroscopy and SQUID. The X-ray diffraction patterns at room temperature confirm the samples to have a single phase of the garnet structure over the whole composition range. The lattice constants of all the samples linearly change with increasing x due to the size of substituted ions in the dodecahedral sites. $Y_{3-x}$ $Gd_{x}$ X$Fe_{4.8}$ $In_{0.2}$ $O_{12}$ system which $Y_{3-x}$ ions are substituted with Gd$^{ 3+}$ ions, the Mossbauer spectrum consists of three Zeeman sextets at room temperature, one due to the $Fe^{3+}$ ions on the octahedral(a-) sites and the others due to the $Fe^{3+}$ ions on the tetrahedral(d-, d'-) sites, respectively. From the hysteresis loop measured by means of SQUID over the whole composition range, the saturation magnetization $M_{s}$ and magnetic moments $\mu_{ B}$ per unit cell have been obtained. The increment of Gd-ion content causes $M_{s}$ and $\mu_{B}$ decrease while the increment of In-ion content does not.

Gasification Characteristics of Biomass and RPF in a 5ton/day Fixed Bed Gasifier (5톤/일 고정층 가스화기를 이용한 바이오매스, RPF 가스화 특성 연구)

  • Yoon, Sang-Jun;Choi, Young-Chan;Lee, See-Hoon;Kim, Jae-Ho;Lee, Jae-Goo
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.75-78
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    • 2006
  • With the increasing environmental consideration and stricter regulations waste gasification is considered to be more attractive technology than conventional incineration for energy recovery as well as material recycling. The experiment for combustible waste was performed In the fixed bed gasifier to investigate the gasification behavior with the operating conditions in a 5ton/day fixed bed gasifier The experiments of operation with 10-50 hours were carried out to determine the effects of bed temperature and oxygen/waste rat io on the syngas composition, calorific value and carbon conversion. The calorific values of the produced syngas decreased with an Increase of bed temperature because combust ion reaet ion more act ively happened. The syngas composition of wood waste gasification is CO: 34.4%, $H_2: 10.7%,\;CH_4: 6.0%,\;CO_2: 48.9%$ and that of RPF is CO: 33.9%, $H_2: 26.1%,\;CH_4: 10.7%,\;CO_2: 29.2%$. The average calorific values of produced gas were about $1,933kcal/Nm^3,\;2,863kcal/Nm^3$, respectively

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Chemical Compositions of the Observed Precipitation in Forest Area on the Border of Highway(Shingal, Seochun) (고속도로변 산림지역(신갈, 서천) 강우의 화학적 조성)

  • 김영채;정동준;김홍률
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.4 no.4
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    • pp.237-247
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    • 2002
  • Air pollution by acid pollutants is problematic in the whole world. Water acidification has already been deteriorating the forest ecosystem. This study was conducted to analyze the acidity and chemical composition of the open precipitation and throughfall at forests with various geographic locations in Korea. The results of this study are as follows; The open precipitation pH was lowest in Seochun. The throughfall pH showed some buffering capacity in only Quercus mongolica stands. In Pinus rigida(Shingal and Seochun) stands, there was little difference from the open precipitation. Chemical composition of the open precipitation for each sampling site showed that $Ca^{2+}$, N $H_{4}$$^{+}$ and S $O_{4}$$^{2-}$ concentrations had higher value than other ions, and except these ions, the small quantity of ions showed different properties to each site. Changes of ion concentrations in the throughfall showed a tendency to increase. ion concentrations of the throughfall increased with washout and nutrient leaching from the trees. In conclusion, the influence was extended to the pure zone, and the frequency of acid rain is increasing. But, if the deposition of pollutants exceeds the capacity of purification, it would damage forest ecosystem. Further investigations are necessary to identify tolerant tree species to acid pollutants.nts.

Ion Exchange Capacity and Phase Separation of Alkali Borosilicate Glass by Substituting $Al_2O_3$ (산화알루미늄의 치환에 따른 붕규산 유리의 분상 미 이온교환성에 관한 연구)

  • 김병호;유영문
    • Journal of the Korean Ceramic Society
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    • v.21 no.1
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    • pp.41-50
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    • 1984
  • The ion-exchange porous glasses were prepared by heat treating and subsequently acid treating the (95-y) $SiO_2$.$yB_2O_3$.$5Na_2O+xAl_2O_3$ glasses with y=55, 45, 35, 25. mole% and x=0, 2, 5, 9 mole% It was then investigated how the cation exchange capacity was affected by the phase separation in these glasses. For that matter such quantities as alkali extraction amount pore volume and specific surface area of the glasses were measured. The phase separation in these glasses was in general suppressed by the addition of $Al_2O_3$ maximally around the composition of 5 mole% $Al_2O_3$ This may be because the micro-phase separation prevailed in the glass of that composition over the macro-phase separation increasing thereby the specific surface area as well as the residual amount Al of after acid-treatment and accordingly the cation exchange capacity. The maximum values of the cation exchange capacity was observed to be about 150meq/100g for the glasses of (40-50) $SiO_2$ (55~45)$yB_2O_3$. $5Na_2O+5Al_2O_3$.

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Viscosities of LaCl3-CsCl Binary Melts (LaCl3-CsCl 2성분계 용융염의 점도)

  • Kim, Kiho
    • Journal of the Korean institute of surface engineering
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    • v.46 no.2
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    • pp.87-92
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    • 2013
  • Viscosities of $LaCl_3$-CsCl binary melts were measured by the capillary method over the range of their liquidus temperatures to about 1200 K. The cell constant were determined by using pure water. The results obtained are summerized as follows: Viscosities of melted $LaCl_3$ were decreased with the content of CsCl for all over the composition range of binary melts. Composition versus viscosity relation for the binary melt showed a non-linear relationship from the additivity line and the deviations showed a maximum value at about 60 mol% CsCl. This suggest the existence of the complex ion of $LaCl_4{^-}$ in the melt. Activation energy for the viscous flow of the binary melts decreased monotonously with the increasing content of CsCl after a few increasement till 40 mol% CsCl. All of these results were the resemble with the viscosities of $LaCl_3$-NaCl binary melts.

Measurements at Kosan, Cheju Island during the Summer, 1994: (I) Aerosol Ion Composition (제주도 고산에서의 1994년 여름 측정: (I) 입자 이온 조성)

  • 김용표;김성주;진현철;백남준;이종훈;김진영;심상규;강창희;허철구
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.3
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    • pp.297-305
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    • 1996
  • Aerosol measurements were carried out at Kosan, Cheju Island, Korea for the period from July 20 to August 10, 1994. Total suspended particles were collected by high volume samplers and PM 2.5 particles with gaseous volatile species were collected by a filter pack sampler and their ionic composition are analyzed. The average mass concentration of PM 2.5 particles was comparable to that of PM 3 particles collected during March, 1994 at the same site but the average non sea-salt sulfate concentration was higher that that of PM 3 particles, implying the fraction of anthropogenic air apllutants during this period is higher than that during March, 1994. During the measurement period, two distincitive patterns were observed, high concentrations of mass and water soluble ions were observed between July 20 and August 1 while those during after August 2 were low. Back trajectory analysis results show that air masses arriving at Kosan during the earlier period were mainly from Korea and Japan while those during the later period were from the North Pacific Ocean. It is suggested that the particle ion concentrations during the later period are marine background concentrations at Kosan during the summertime.

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Weekday/weekend Chemical Characteristics of Water-Soluble Components of PM10 at Busan in Springtime (부산지역 봄철 주중/주말의 PM10 중 이온성분의 화학적 조성)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.24 no.6
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    • pp.785-792
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    • 2015
  • This study investigates weekday/weekend characteristics of $PM_{10}$ concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO_4{^{2-}}$ to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. $[NO_3{^-}/SO_4{^{2-}}]$ ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and $Cl^-/Na^+$ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

Characteristics of $K_2NiF_4$-Type Oxides $(Sr,Sm)_2FeO_{~4}$

  • 요철현;이은석
    • Bulletin of the Korean Chemical Society
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    • v.17 no.4
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    • pp.321-324
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    • 1996
  • Sr1+xSm1-xFeO4-y solid solutions with a composition range 0.00 ≤x≤1.00 have been prepared at 1200 ℃ in air under normal atmospheric pressure. All the solutions exhibit the K2NiF4-type structure of tetragonal system. Mohr salt analysis shows that the mole ratio of Fe4+ ion to Fe3+ ion or the τ value increases with the x value. Nonstoichiometric chemical formulas have been formulated from the x, τ, and y values. Electrical conductivity was measured in the temperature range of 173-373 K under atmospheric air pressure. The conductivities of each sample are varied within the semiconductivity range. The conductivity at constant temperature increases steadily with x value and activation energies are varied from 0.14 to 0.32 eV. The conduction mechanism of the ferrite system may be proposed as a hopping model of conduction electrons between the mixed valence states. The Mossbauer spectrum for the composition of x=0.00 shows a six line pattern by which the existence of Fe3+(I.S.=0.32 mm/sec) can only be identified. The spectra for the compositions of x=0.50 and 1.00 presents broad single line patterns showing a mixed valence state.