• Title/Summary/Keyword: MnAl

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Mineralchemie der Klinopyroxen vom tephritischen Gesteine im Kaiserstuhl, BRD (카이져슈튤에서 산출되는 테프라이트질 화산암내의 단사휘석에 관한 광물화학적 고찰)

  • Kim, Jin-Seop;Keller, Jorg
    • Journal of the Mineralogical Society of Korea
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    • v.2 no.2
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    • pp.100-106
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    • 1989
  • Die Titan-Augite sind die dominierenden Einsprenglings- und Grundmassephasen in allen tephritischen Gesteinen im Kaiserstuhl. Mg-Werte ($Mg/Mg+Fe^{2+}+Mn$) der Pyroxene schwanken von 60-85. Der FATS- und TITS-Anteil nimmt von phonolithischem Basanit und -Tephrit zum fraktionierten phonolithischen Tephrit hin ab. Die Kpx der einzelnen Gesteinsgruppen zeigen auch einen Fraktionier-ungstrend, der durch Abnahme von Si und Zunahme von Al vom phonolithischen Basanit und -Tephrit zum fraktionierten phonolithischen Tephrit gekennzeichnet ist. Der in Alkaligesteinen gewohnlich auftretende $gr{\ddot{u}}ne$ Kern der Px ist Fe-reicher und $Ti-{\ddot{a}}rmer$ als der $hellbra{\ddot{u}}nliche$-farblose Rand. Die $gr{\ddot{u}}nen$ Kerne weisen $gegen{\ddot{u}}ber$ den $hellbr{\ddot{a}}unlichen$ Randern $h{\ddot{o}}here$ $Na/Fe^{+3}$-Verhaltnisse auf.

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Characteristics of Heavy Metallic Elements of PM10 for Yellow sand and Non-Yellow sand during Springtime of 2002 at Busan (2002년 부산지역 봄철 황사/비황사시 PM10 중의 중금속 농도 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Impact Assessment
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    • v.12 no.2
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    • pp.99-108
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    • 2003
  • We collected and analyzed PM10 samples to account for the characteristics of heavy metallic elements for yellow sand and non-yellow sand during springtime of 2002 at Busan, The mean PM10 mass concentration for springtime of 2002 was $219.82{\mu}g/m^3$ with the maximum $787.50{\mu}g/m^3$ and the minimum $19.44{\mu}g/m^3$. The mean concentration of metallic elements contained in PM10 are shown as follows : Si>Ca>Fe>Al>Na, respectively. The ratio of mean PM10 mass concentration for yellow sand($362.7{\mu}g/m^3$) to that for non-yellow sand($48.3{\mu}g/m^3$) was 7.5, the significant positive correlation (P<0.05) was found between yellow sand and non-yellow sand. The metallic elements concentration ratios of yellow sand to the non-yellow sand were over 10 times for Al, Ca, Mg, 4~8 times for Fe, Si, Mn. But the concentration of Na, Cu, Zn for non-yellow sand was higher than those of yellow sand. The crustal enrichment factor of Cd, Cu, Pb, Zn, Cr, K, Mn, Na, Ni for yellow sand was higher that of non-yellow sand over 10 times, and concentration rate of soil particles of yellow sand was increased 2.3 times that of nonyellow sand.

Method for Measuring Prompt Fission Neutron Energy Spectrum by Means of Threshold Activation Detectors (발단 방사화 검출기를 이용한 핵분열 즉발 중성자 에너지 스펙트럼 측정방법)

  • 노성기;신희성;박종묵
    • Nuclear Engineering and Technology
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    • v.22 no.4
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    • pp.410-415
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    • 1990
  • Prompt fission neutron energy spectrum as a function of energies of neutron inducing fission has been calculated en the basis of the Madland-Nix(MN) model. The resultant spectra have been weighted to excitation functions of $^{27}$ Al(n, $\alpha$), $^{32}$ S(n, p) and $^{115}$ In(n, n') threshold reactions in order to get the average cross sections and then spectral indices which are defined as the average cross section ratio for two selective threshold reactions among the above three. It is appeared that spectral indices together with the neutron spectra are varying with energies of neutron inducing fission. This may indicate that the prompt fission neutron energy spectrum can be determined by measuring experimentally the spectral index.

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Degradation of PDP Phosphors Under VUV Excitation (PDP 형광체의 진공 자외선 조사에 따른 열화 특성)

  • Lee, R.Y.;Lee, S.H.;KIm, Y.H.
    • Korean Journal of Materials Research
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    • v.12 no.9
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    • pp.735-739
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    • 2002
  • $(Y,Gd)BO_3$: Eu, $Zn_2$$SiO_4$ : Mn and $BaMgAl_{10}$ $O_{17}$ : Eu phosphors used in PDP were continuously irradiated by vacuum ultra violet generated from the penning gas (96%Ar+4%Xe) discharge and then the change of emitting intensity with time was investigated. The brightness of these phosphors decreased exponentially with VUV excitation time. The experimental data showed that the degradation rate increased in the order of $Zn_2$$SiO_4$ : Mn>(Y,Gd)$BO_3$: Eu>$BaMgAl_{10}$ $O_{17}$ : Eu phosphor. This different degradation property of phosphors was interpreted in terms of brightness saturation and stability against VUV irradiation. It was found that the degradation property of $(Y,Gd)BO_3$ : Eu red phosphor synthesized by ultrasonic thermal spray was superior to commercial phosphor.

A Study on Physical Properties and Catalytic Combustion of Methane of Sr Hexaaluminate Prepared using 1-butanol and Ethylene Glycol (1-butanol과 ethylene glycol을 이용하여 합성한 Sr hexaaluminate의 물리적 특성 및 메탄 연소 반응에 관한 연구)

  • Shon, Jung Min;Woo, Seong Ihl
    • Korean Chemical Engineering Research
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    • v.45 no.3
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    • pp.209-214
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    • 2007
  • Sr hexaaluminate($Sr_{1-x}La_xMnAl_{11}O_{19-\alpha}$) were prepared by sol-gel method of metal alkoxide with 1-butanol or ethylene glycol as a solvent. The physical properties of prepared hexaaluminates were examined by TG/DTA, XRD and $N_2$ adsorption. When ethylene glycol was used as a solvent, the decomposition reaction and dehydroxylation reaction was observed above $400^{\circ}C$ and the temperature of the formation of a crystal structure of hexaaluminate was also increased resulting in small specific surface area and low catalytic activity of methane compared to Sr-hexaaluminate with 1-butanol.

Estimation of Source Contribution of Particulate Matter in Taegu Area using Factor Analysis (다변량 통계분석법을 이용한 대구지역 부유분진의 오염원 기여도 추정)

  • 최성우;송형도
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.1-8
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    • 2000
  • The objective of this study was to identify the sources and to estimate the source contributions to the atmospheric TSP(total suspended particulate matter) and PM-10(particulate matter with aerodynamic diameters less than 10$\mu\textrm{m}$) concentration in Taegu area. A total of 84 samples was collected during the January to December 1999. TSP and PM-10 were collected on filters by portable air sampler, and heavy metals in TSP and PM-배 were analyzed by ICO(Inductively Coupled Plasma Spectrometery) after preliminary treatment. The results were follow as : First, annual average of TSP and PM-10 concentration was 123 and 69$\mu\textrm{g}$/㎥ respectively. The concentration of TSP and PM-10 were highest in winter season compared to other seasons. Second, the concentration of Al, Fe, Mn were higher in TSP than in PM-10, indicating that these heavy metals are generally associate with natural contributions. Third, metal combinations showed that a high correlation among concentrations of heavy metals were follows: As Al, Fe and Mn in TSP ; Ni, Cr, Cd and Pb in PM-10. Finally, Statistical analysis was performed using Principal Components Analysis(PCA) in order to find possible sources of the pollutants. The factor analysis was permitted to identify four major sources(soil/road dust resuspension, waste incineration, furl combustion, vehicular emission) in each fraction. These source accounted for at least 83, 85% of variance of TSP and PM-10 concentration in Taegu area.

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Characteristics of Hydrogen Sulfide Removal by a Catalyst-assisted Plasma System (촉매-플라즈마 반응 시스템을 이용한 황화수소의 처리특성 연구)

  • Lee, Jeong-Keun;Kim, Hyeok-Gyu;Bong, Choon-Keun;Park, Seong-Jin;Lee, Myong-Hwa;Hwang, Ui-Hyun;Kim, Jong-Ho
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.4
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    • pp.379-386
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    • 2011
  • Catalyst-assisted plasma system with a DBD (Dielectric Barrier Discharge) reactor was used to remove hydrogen sulfide, which is one of the odorous species in this study. The ${\gamma}-Al_2O_3$ and ${\beta}$-Zeolite catalysts impregnated by Ag, Cu and Mn species were employed as catalysts and their $H_2S$ removal characteristics under plasma irradiation were investigated. From the experimental study, we found that the $H_2S$ removal efficiency increases with decreasing space velocity in the system and increasing specific input energy. Furthermore, ${\beta}$-Zeolite catalysts are efficient to remove $H_2S$ than ${\gamma}-Al_2O_3$ catalysts. Especially, the catalysts impregnated by Ag have higher removal efficiency than other catalysts (Cu, Mn).

Study on Magnetic Behavior of Zn1-xMnxO Films Grown on Si and α-Al2O3 Substrates by Sol-gel Method and Powders

  • Kim, Young-Mi;Park, Il-Woo
    • Journal of the Korean Magnetic Resonance Society
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    • v.12 no.1
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    • pp.26-32
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    • 2008
  • We report on the ferromagnetic characteristics of $Zn_{1-x}Mn_xO$ films (x = 0.3) prepared by sol-gel method on the silicon and (0001) ${\alpha}-Al_2O_3$ substrates at the annealing temperature of 700$^{\circ}C$. Magnetic measurements show that Curie temperature ($T_C$) and the coercive field ($H_C$) for the film on the silicon are about 32 K and about 275 Oe, while those for that on the sapphire are about 32 K and 425 Oe, respectively. Energy dispersive spectroscopy and transmission electron microscopy measurements suggest that ferromagnetic precipitates originated by manganese oxide compound formed at the interfaces of the both substrates may be responsible for the observed ferromagnetic behavior of the films. Electron paramagnetic resonance study of the powders up to the concentration of x=0.15 supports the result.

Comparison of Heavy Metal Contents in Eyeliner Products -Focused on Domestic and Foreign Cosmetic Brands-

  • Lee, Kee-Young;Kim, Jeong-hee
    • Journal of Fashion Business
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    • v.19 no.3
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    • pp.113-120
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    • 2015
  • Heavy metal ingredients of eyeliner product could cause side effect ranging from simple irritation, keratitis, corneal epithelium inflammation, eyelid dermatitis and dry eye symptoms have been reported. This study was conducted in order to prepare fundamental data for acceptable quality level heavy metal ingredients in the domestic and foreign cosmetic brand eyeliner products and to assess theirs the heavy metal concentrations. We measured the concentration of 5 heavy metals in 10 eyeliner products using ICP/MS-LC. According to the results, the average metal concentrations were as follows.; In case of domestic eyeliner products, 289.4 ppm for aluminium(Al), 304 ppm for manganese(Mn), 44 ppm for nickel(Ni), 0.58 ppm for arsenic(As) and 0.35 ppm for lead(Pb). In case of Foreign eyeliner products, 11337.8 ppm for aluminium(Al), 1678.8 ppm for manganese(Mn), 74.2 ppm for nickel(Ni), 1 ppm for arsenic(As) and 0.8 ppm for lead(Pb). Foreign products contained higher amounts of the two elements(Pb, As) compared to domestic ones. Also, greater concentrations of arsenic(As) were detected from waterproof products than non-waterproof ones. In conclusion, for safety reasons we suggested the amounts of heavy metals from the domestic and foreign eyeliner products. This finding will be helpful to provide the fundamental data which is standard of toxicological heavy metals acceptable on eyeliner products.

Studies on the Ore Mineralogy and Litho-geochemistry of the Sheba Deposit, Barberton Greenstone Belt, South Africa

  • Altigani, Mohammed Alnagashi Hassan
    • Economic and Environmental Geology
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    • v.54 no.2
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    • pp.213-232
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    • 2021
  • Ore criteria at the Sheba Deposit indicate orogenic mineralization type. Rocks and mineral assemblages suggest low formation-temperature of green-schist facies. Pyrite found in two generations; Type1 is irregular grains, contains higher arsenic and gold contents, compared to the relatively younger phase Type2 pyrite, which is composed of euhedral grains, found adjacent to late quartz-carbonate veins or at rims of type1 pyrite. Two gold generations were identified; type1 found included in sulphides (mainly pyrite). The second gold type was remobilized (secondary) into free-lodes within silicates (mainly quartz). Gold fineness is high, as gold contains up to 95 wt. % Au, Ag up to 3.5 wt. %, and traces of Cu, Ni, and Fe. Pyrite type2 contains tiny mineral domains (rich in Al, Mn, Hg, Se, Ti, V, and Cr). Zoning, and replacement textures are common, suggesting multiple mineralization stages. The distribution and relationships of trace elements in pyrite type2 indicate three formation patterns: (1) Al, Mn, Hg, Se, Ti, V, Cr, and Sn are homogeneously distributed in pyrite, reflecting a synchronous formation. (2) As, Ni, Co, Zn, and Sb display heterogeneous distribution pattern in pyrite, which may indicate post-formation existence due to other activities. (3) Au and Ag show both distribution patterns within pyrite, suggesting that gold is found both in microscopic phases and as chemically bounded phase.