• Title/Summary/Keyword: ZnS:Cu,Al

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Study on the Mineral and Heavy Metal Contents in the Hair of Preschool Aged Autistic Children (자폐아동 모발에서의 미네랄 및 중금속 함량에 관한 연구)

  • Jung, Myung-Ae;Jang, Hyun-Seo;Park, Eun-Ju;Lee, Han-Woo;Choi, Jeong-Hwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.11
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    • pp.1422-1426
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    • 2008
  • The purpose of this study was to test characteristics between normal and autistic children via comparison of nutrient intakes, hair mineral, blood free radical, and serotonin contents. A total of 50 children aged 3-9 were divided into two main groups of normal control children (n=22) and autistic children (n=28) tested by child psychiatrist. The nutrient intakes by 24-hour recall method were no significantly different between the two groups. The concentrations of toxic mineral, such as cadmium (Cd) and lead (Pb) in hair of autistic children were significantly higher, while concentration of antioxidant mineral (Cu, Zn, Fe) was lower than that of normal children. The autistic children had significantly higher concentrations of blood free radical than that of normal children. No significant difference was observed in serotonin concentration between the two groups. Our results suggest a possible role of increased toxic mineral and free radical, both of which may be relevant to the pathophysiology of autism in children with developmental delay.

A Study on Chemical Composition of Fine Particles in the Sungdong Area, Seoul, Korea (서울 성동구 지역 미세먼지의 화학적 조성에 관한 연구)

  • 조용성;이홍석;김윤신;이종태;박진수
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.665-676
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    • 2003
  • To investigate the chemical characteristics of PM__2.5/ in Seoul, Korea, atmospheric particulate matters were collected using a PM__10/ dichotomous sampler including PM__10/ and PM__2.5/ inlet during the period of October 2000 to September 2001. The Inductively Coupled Plasma-Mass Spectromety (ICP-MS), ion Chromatography (IC) methods were used to determine the concentration of both metal and ionic species. A statistical analysis was performed for the heavy metals data set using a principal component analysis (PCA) to derived important factors inherent in the interactions among the variables. The mean concentrations of ambient PM__2.5/ and PM/sub10/ were 24.47 and 45.27 μgμg/㎥, respectively. PM__2.5/ masses also showed temporal variations both yearly and seasonally. The ratios of PM__2.5/PM__10/ was 0.54, which similar to the value of 0.60 in North America. Soil-related chemical components (such as Al, Ca, Fe, Si, and Mn) were abundant in PM__10/, while anthropogenic components (such as As, Cd, Cr, V, Zn and Pb) were abundant in PM2s. Total water soluble ions constituted 30∼50 % of PM__2.5/ mass, and sulfate, nitrate and ammonium were main components in water soluble ions. Reactive farms of NH44\^\^+/were considered as NH44NO33 and (NH44)22SO44 during the sampling periods. In the results of PCA for PM__2.5/, we identified three principal components. Major contribution to PM__2.5/ seemed to be soil, oil combustion, unidentified source. Further study, the detailed interpretation of these data will need efforts in order to identify emission sources.

Effect of Hot Spring Water on Dough Fermentation and Quality of Bread (온천수가 반죽의 발효와 품질에 미치는 영향)

  • 이예경;김순동
    • Journal of the East Asian Society of Dietary Life
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    • v.13 no.1
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    • pp.56-63
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    • 2003
  • The dough fermentation and the quality of bread prepared with different kinds of water such as distilled water, tap water and diluted hot spring water(SW) from Gyungsan Sipan hot spring were investigated. Content of total soluble solid in the hot spring water was 8,765 ppm and contents of Na, Ca, Mg and K as major elements was 2,296, 287, 65 and 8 ppm, respectively. Content of Fe, Cu, Co, F, Zn, Al, S, Mo, Se and Si as minor elements was in the range of 0.002~5.2 ppm. The pH(6.95~7.68) of the dough prepared with diluted hot spring water(I, 55 times; II, 4 times; III, 2 times) was higher than that of distilled water. The dough volume after the 1st fermentation was expecially lower in the III, but the volume of the dough prepared with III adjusted pH to 5.5 was higher than that of the control. The hardness and the strength were higher than those of the control, but the scores were love. than those of the control in case of pH adjustment(pH 5.5). The cohesiveness was also lower than that of the control in the bread with diluted hot spring water. Softness and stickiness of the bread(III) were hisher than those of the control. But overall acceptability was the highest in the II.

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Developement of Heavy Metal Adsorbent Utilising Natural Zeolite (천연(天然) Zeolite를 이용(利用)한 중금속(重金屬) 흡착제(吸着劑)의 개발(開發))

  • Kim, S.S.;Park, M.;Hur, N.H.;Choi, J.
    • Korean Journal of Environmental Agriculture
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    • v.10 no.1
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    • pp.11-19
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    • 1991
  • This study was carried out to develop the low-priced adsorbent by synthesizing the zeolite of high CEC with the natural zeolite and examining the ability of this zeolite to adsorb heavy metals. The dominant clay minerals were clinoptilolite and mordenite in natural zeolite, while phillipsite in the synthesized zeolite. Adsorption reaction of Cu and Zn on clays were reached to equilibrium after 1 hr. The amount of adsorption was increased as the concentrations of heavy metals or the initial pH of suspension was increased. The synthesized zeolite adsorbed heavy metals about twice as much as the natural zeolite. The adsorption of heavy metals on the synthesized zeolite was less affected by the initial pH of suspension than that on natural zeolite. At cumulative adsorption, the synthesized zeolite adsorbed much more heavy metals at early three treatments than the natural zeolite did. The amount of desorption by chloride salts was increased as the concentration of chloride salts was increased. The ability of salt to desorb was in the order of NaCl>CaC12CaC12>AlC13AlC13. It is estimated that the ability of the synthesized zeolite to remove heavy metals was better than that of the natural zeolite.

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Element Dispersion by the Wallrock Alteration of Daehyun Gold-silver Deposit (대현 금-은광상의 모암변질에 따른 원소분산)

  • Yoo, Bong Chul
    • Economic and Environmental Geology
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    • v.46 no.2
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    • pp.199-206
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    • 2013
  • The Daehyun gold-silver deposit consists of two hydrothermal quartz veins that fill NE-trending fractures in the Cambro-Ordovician calcitic marble. I have sampled wallrock, hydrothermaly-altered rock and gold-silver ore vein to study the element dispersion and element gain/loss during wallrock alteration. The hydrothermal alteration doesn't remarkably recognized at this deposit and consists of mainly calcite, dolomite, quartz and minor epidote. The ore minerals composed of arsenopyrite, pyrrhotite, pyrite, sphalerite, stannite, chalcopyrite, galena, electrum, native bismuth and silver-bearing mineral. Based on analyzed data, the chemical composition of wallrock consists of mainly SiO2SiO2, CaO, CO2CO2 with amounts of Al2O3Al2O3, Fe2O3(T)Fe2O3(T) and MgO. The contents of SiO2SiO2, Fe2O3(T)Fe2O3(T), MgO, CaO and CO2CO2 vary significantly with distance from ore vein. The element dispersion doesn't remarkably recognized during wallrock alteration and only occurs near the ore vein margin because of physical and chemical properties of wallrock. Remarkable gain elements during wallrock alteration are Fe2O3(T)Fe2O3(T), total S, Ag, As, Bi, Cd, Cu, Ni, Pb, Sb, Sn, W and Zn. Remarkable loss elements are SiO2SiO2, MnO, MgO, CaO. CO2CO2 and Sr. Therefore, Our result may be used when geochemical exploration carry out at deposits hosted calcitic marble in the Hwanggangri metallogenic district.

Assessment of Atmospheric Corrosivity at Jeju Island (제주도 대기환경의 부식성 평가)

  • KIM GUI-SHIK;YANG KYEONG-CHO;HU CHUL-GOO;SONG JEONG-HWA
    • Journal of Ocean Engineering and Technology
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    • v.19 no.5 s.66
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    • pp.50-57
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    • 2005
  • This study has been conducted to investigate corrosivity of carbon steel, Cu, Zn and Al for one year from Sept. 2003 to Aug. 2004. A model of ISO 9223-ISO 9226 that represents the relation between metal corrosions and environmental parameters was used for atmospheric corrosion evaluations. Environmental parameters for these evaluations are time of wetness(TOW), SO2SO2 and Chloride. Corrosion rates for four metals which are exposed indoors and outdoors were measured on five locations in Jeju Island; Gosan, Seogwipo, Seongsan, Chuna hill and Jeju city. The environmental factor of atmospheric corrosion of Jeju Island for SO2SO2 class is P0, a clean area. TOW as T3 and T4 indicates that Jeju has the characteristics of a tropical area. Chlorides class within 3 km from the coast show the features of costal area as S2 and S3 classes. Chuna hill show the features of woodland as a S1 class. In Corrosion classes of each site which was measured outdoors is higher than indoors. Gosan is the highest class as the rank of C5, and indicated that they're ranked as C3 or C4.

Selective Leaching Process of Precious Metals (Au, Ag, etc.) from Waste Printed Circuit Boards (PCBs) (廢 PCBs부터 귀금속(Au, Ag 등)의 선택적 침출공정)

  • 오치정;이성오;국남표;김주환;김명준
    • Resources Recycling
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    • v.10 no.5
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    • pp.29-35
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    • 2001
  • This study was carried out to recover gold, silver and valuable metals from the printed circuit boards (PCBs) of waste computers. PCBs samples were crushed under 1 mm by a shredder and separated into 30% conducting and loft nonconducting materials by an electrostatic separator. The conducting materials contained valuable metals which were then used as feed materials for magnetic separation. 42% of magnetic materials from the conducting materials was removed by magnetic separation as nonvaluable materials and the others, 58% of non magnetic materials, was used as leaching samples containing 0.227 mg/g Au and 0.697 mg/g Ag. Using the materials of leaching from magnetic separation, more than 95% of copper, iron, zinc, nickel and aluminium was dissolved in 2.0M sulfuric acid solution, added with 0.2M hydrogen peroxide at 85C85C. Au and Ag were not extracted in this solution. On the other hand, more than 95% of gold and 100% of silver were leached by the selective leaching with a mixed solvent (0.2M(NH4NH4)22S2S2O3O3,0.02M CuSO4CuSO4,0.4M NH4NH4OH). Finally, the residues were reacted with a NaCl solution to leach Pb whereas sulfuric acid was used to leach Sn. Recoveries reached 95% and 98% in solution, respectively.

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Fabrication of P-type Transparent Oxide Semiconductor SrCu2O2 Thin Films by RF Magnetron Sputtering (RF 마그네트론 스퍼터링을 이용한 p 타입 투명전도 산화물 SrCu2O2 박막의 제조)

  • Seok, Hye-Won;Kim, Sei-Ki;Lee, Hyun-Seok;Lim, Tae-Young;Hwang, Jong-Hee;Choi, Duck-Kyun
    • Korean Journal of Materials Research
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    • v.20 no.12
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    • pp.676-680
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    • 2010
  • Most TCOs such as ITO, AZO(Al-doped ZnO), FTO(F-doped SnO2SnO2) etc., which have been widely used in LCD, touch panel, solar cell, and organic LEDs etc. as transparent electrode material reveal n-type conductivity. But in order to realize transparent circuit, transparent p-n junction, and introduction of transparent p-type materials are prerequisite. Additional prerequisite condition is optical transparency in visible spectral region. Oxide based materials usually have a wide optical bandgap more than ~3.0 eV. In this study, single-phase transparent semiconductor of SrCu2O2SrCu2O2, which shows p-type conductivity, have been synthesized by 2-step solid state reaction at 950C950C under N2N2 atmosphere, and single-phase SrCu2O2SrCu2O2 thin films of p-type TCOs have been deposited by RF magnetron sputtering on alkali-free glass substrate from single-phase target at 500C500C, 1% H2H2/(Ar + H2H2) atmosphere. 3% H2H2/(Ar + H2H2) resulted in formation of second phases. Hall measurements confirmed the p-type nature of the fabricated SrCu2O2SrCu2O2 thin films. The electrical conductivity, mobility of carrier and carrier density 5.27×102S/cm5.27×102S/cm, 2.2cm22.2cm2/Vs, 1.53×1017/cm31.53×1017/cm3 a room temperature, respectively. Transmittance and optical band-gap of the SrCu2O2SrCu2O2 thin films revealed 62% at 550 nm and 3.28 eV. The electrical and optical properties of the obtained SrCu2O2SrCu2O2 thin films deposited by RF magnetron sputtering were compared with those deposited by PLD and e-beam.

Classification of Individual Ambient Particles by CCSEM (CCSEM을 이용한 대기 중 개별분진의 분류에 관한 연구)

  • 장여진;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.5
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    • pp.345-353
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    • 1997
  • The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.

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Characterization of CIGS Solar Cell for Flexible Steel Substrate by Surface Roughness (유연 철강기판 표면조도에 따른 CIGS 태양전지의 특성 분석)

  • Kim, Daesung;Hwang, Moonsick;Kim, Daekyong;Lee, Duckhoon;Kim, Taesung
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.58.1-58.1
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    • 2011
  • CIS(CuInSe2)계 화합물 태양전지는 높은 광흡수계수와 열적 안정성으로 고효율 태양전지 제조가 가능하여 태양전지용 광흡수층으로 매우 이상적이다. 미국 NREL에서는 이러한 CIGS 태양전지를 Co-evaporation 방법으로 제조 20%이상의 에너지 변환 효율을 달성하였다고 보고하였다. CIGS 태양전지의 경우 기존의 유리 기판 대신 유연한 철강 기판을 사용해 태양 전지를 flexible하게 제조 할 수 있다는 장점이 있다. 이러한 flexible 태양전지의 경우 기존의 rigid 태양전지의 적용분야 뿐만 아니라 BIPV, 선박, 장난감, 군용, 자동차등 더욱 더 많은 분야에 활용이 가능하다. 본 연구에서는 기존의 rigid한 기판인 soda lime glass와 flexible 기판인 stainless steel 기판으로 소자를 제조하여 효율을 비교 분석 및 stainless steel 기판의 표면 처리 방법에 따라서 표면 조도의 특성을 분석하여 stainless steel 기판별 효율 특성도 비교 분석 하였다. 후면전극으로는 약 1μm1μm의 Mo를 DC Sputtering 방법을 이용하여 증착하였고, CIGS 광흡수층은 약 2.5μm2.5μm의 두께로 미국의 NREL과 같은 3 stage 방식을 이용하여 광흡수층을 Co-Evaporation 방법으로 제조하였고, 버퍼층인CdS는 약 50nm의 두께로 CBD 방법으로 제조 하였으며, 창층인 ZnO는 약 500nm 두께로 RF Sputtering 방법으로 제조 하였고, 마지막으로 약 1μm1μm 두께의 Al 전면전극은 Thermal Evaporation 방법으로 제조 하였다. 소자의 물리적, 전기적 특성을 분석하기위해 FE-SEM, AFM, Solar Cell Simulator 분석을 실시하였다.

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