• Title/Summary/Keyword: MgO(001)

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Magnetism and Magnetocrystalline Anisotropy of Ni/Fe(001) Surface: A First Principles Study (Ni/Fe(001)의 자성과 자기이방성에 대한 제일원리계산)

  • Kwon, Oryong;Hong, Soon Cheol
    • Journal of the Korean Magnetics Society
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    • v.25 no.4
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    • pp.101-105
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    • 2015
  • Recent theoretical calculations predicted that a system composed exclusively of 3d transition metals without 4d/5d transition metals or rare earth metals can have strong perpendicular magnetocrystalline anisotropy (MCA) if Fe and Ni layers are arranged appropriately. They considered only Fe-terminated surfaces, noting that Fe/MgO(001) and CoFeB/MgO(001) show strong perpendicular MCA. In this paper, we investigate magnetism and MCA of Ni/Fe(001) surface where Ni layer is positioned at the surface, by using complementarily the first principles calculational methods of Vienna Ab-initio Simulation Package (VASP) and Full-potential Linearized Augmented Plane Wave (FLAPW) method. Comparing results of magnetism and MCA obtained by VASP with the results by FLAPW method, we find the VASP results do not show big difference from results by FLAPW method. Magnetic moments of Fe and Ni are enhanced due to strong hybridization between Fe and Ni bands. MCA of Ni/Fe(001) is parallel to the surface, which implies the surface termination plays a crucial role in determining MCA of a system.

Effect of $Mg^{2+}$ co-doping on luminescent properties of $ZnGa_2O_4:Mn^{2+}$

  • Singh, Binod Kumar;Bartwal, Kunwar Singh;Ryu, Ho-Jin
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.4
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    • pp.29-32
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    • 2007
  • Zinc gallate, $ZnGa_2O_4:Mn^{2+}$ co-doped with different concentrations of $Mg^{2+}$ (0.001- 0.5 mol%) was prepared by solid state synthesis method. These compositions were investigated for their photoluminescence and cathodoluminescence properties. The optimized composition $Zn_{0.990}Mg_{0.005}Ga_2O_4:Mn_{0.005}$ shows higher luminescence intensity compared to the parent phosphor. The intense green emission peak was found at 504 nm. The $Mg^{2+}$ doping does not affect much the decay time. It remains <10 ms for these compositions which make them potential candidate for application in TV screens.

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Synthesis and Optical Characteristics of Green-Emitting (Mg,Zn)$Al_2O_4:Mn^{2+}$ Phosphor for 3D- PDP Applications

  • Han, Bo-Yong;Yoo, Jae-Soo;Heo, Eun-Gi;Yoo, Young-Gil
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.272-275
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    • 2009
  • A new green phosphor, ($Mg_{1-x-yZnx)$)$Al_2O_4:Mn^{2+}{_y}$ (0 x 0.6, 0.001 y 0.01), was synthesized by a flux-assisted solid reaction and its vacuum ultraviolet (VUV) excitation and emission characteristics were examined in this study. The chromaticity and peak intensity of the $(Mg_{0.79}Zn_{0.2})Al_2O_4:Mn^{2+}{_{0.01}}$ (x = 0.177, y = 0.745) phosphor were found to be more desirable than that of $Zn_2SiO_4:Mn^{2+}$ (x = 0.216, y = 0.72) phosphor as a green primary color.

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A Study on the Food Intake Sodium and Potassium Intakes and Urinary Excretion of Preschool Children in Pusan (부산지역 학령전 아동의 식품섭취와 나트륨, 칼륨의 섭취 및 소변중 배설실태에 관한 연구)

  • 임화재
    • Journal of Nutrition and Health
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    • v.33 no.6
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    • pp.647-659
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    • 2000
  • o assess the food intake and the sodium and potassium intakes and urinary excretion of preschool children in Pusan and to evaluate the relationship among variables dietary behaviors food and nutrient intake and 24hr urinary sodium and potassium excretion were measured with 97 subjects. The mean sodium and potassium intakes were 1890. 1mg(82,2meq) and 1479.7mg(37.8meq) respectively. The mean potassium intake(p<0.05) and density(p<0.01) were significantly low at the group who had food intake pattern absen of fruit and daily groups. The mean urinary sodium and potassium excretion were 735.3mg(32.0meq) and 418.7mg(10.7meq) respectively. The mean sodium intake(p<0.01) and urinary excretion were 735.3mg(32.0meq) and 418.7mg(10.7meq) respectively. The mean sodium intake(p<0.01) and urinary excretion (p<0.001, p<0.001) energy intake(p<0.01) sodium intake and density (p<0.001, p<0.05) the food number and intake frequency of vegetable group consumed (p<0.01, p<0.01) dietary frequency score(p<0.05) and negative correlations with the food number and frequency of dairy group consumed (p<0.05 p<0.05) The urinary potassium excretion showed positive correlations with height and weight(p<0.05, p<0.01) urine volume and urinary creatinie excretion(p<0.01 p<0.001) potassium intake(p<0.05) food number and intake frequency of dairy group consumed (p<0.05, p<0.001). Based on the results urinary sodium excretion was related to age sodium intake and food intake of vegetable and dairy group and urinary potassium excretion was related to potassium intake and food intake of dairy group. So nutritional education is needed in order to decrease sodium intake especially from food intake of vegetable group when preschool children have less food intake of diary group,.

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A Study on the Eutrophication in Artificial Lakes in Chonnam Area (全南地方의 一部 人工湖水의 富營養化에 관한 조사연구)

  • Kim, Seung Ho
    • Journal of Environmental Health Sciences
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    • v.11 no.1
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    • pp.15-28
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    • 1985
  • In order to analyze the water quality in artificial lakes in Chonnam area, a chemical and biological examination of Dongbock Lake and Changsung Lake was conducted from September to December 1983 and May 1984. A summary of the surveyed results is as follows 1. In Dongbock Lake, pH ranged from 7.2-8.1, D.O.: 8.2-12.6mg/l, B.O.D.: 4.4-22.1 mg/l, C.O.D.: 1.0-3.4rag/l, Cl$^-$: 5.9-11.9mg/l, Total-P: 0.001-0.071 mg/l, and Total -N: 0.016-0.697 mg/l, respectively. 2. In Changsung Lake, pH ranged from 7.2-8.1, D.O.: 8.1-9.8mg/l, B.O.D.: 0.9-2.9mg/l, C.O.D.: 1.9-3.4mg/l. Total- P: 0.006-0.016mg/l and Total -N:0.006-0.033mg/l, respectively. 3. The Phytoplankton identified in this investigation were distributed in a total of 46 genera and 76 spedes in Dongbock Lake 37 genera and 45 species in Changsung Lake. 4. In Dongbock Lake, it was found that the dominant algae were Melosira sp., Microcystis sp. and Synedra sp. in September Melosira sp. and Microcytis sp. in October, but Cymbella sp., Naviculla sp. and Nitzschis sp. were also observed in OctoberAsterionella sp., Melosira sp. and Microsystis sp. in November and Melosira sp., Asterionella sp sp. and Synedra sp. in December 1983. 5. In Changsung Lake, it was found that the dominant algae were Melosira sp., Lyngrbya sp. and Microcystis in September Melosira sp. and Synedra sp. in October and November and Melosira sp., Lyngbya sp. and Asterionella sp. in December 1983. The dominant algae were Melosira sp., Lyngbya sp. and Euglena sp. in May 1984. 6. It was found that the dominant algae in both Dongbock and Changsung Lakes were Microcystis sp., Melosira sp. and Asterionella sp.. Which are strongly related with water-bloom. Therefore, it could be suggested that the eutrophication phenomena is going to occur very easily in Dongbock Lake and possibly in Changsung Lake.

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Effect of SipJeonDaeBo-Decoction on Blood Metal Level in Rats (십전대보탕(十全大補湯)을 투여한 흰쥐의 혈액중 금속농도변화에 관한 연구)

  • Joh Hoo-Li;Lee Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.2
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    • pp.151-170
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    • 1999
  • This study was to investigate the metal accumulation from SipJeonDaeBo-Decoction to rat blood of Sprague Dawley. 1. There were no significance in body weight, water dose feed ingestion quantity, liver, kidney, brain, bone weights between the control and the experimental groups. Under the experiment with drinking waters was no metal ${\sim}\;0.65mg/L$ detected. Metal level within feed found 0.0001-376.983mg/kg. 2. In the pack of SipJeonDaeBo-decoction, there detected no metal ${\sim}2.086mg/L$ 3. After P.O(per os) SipJeonDaeBo-decoction, As is detected $2.390{\pm}0.812mg/kg$ in blood; Cd $0.001{\pm}0.001mg/kg$, Co $0.003{\pm}0.001mg/kg$, Cr $0.432{\pm}0.234mg/kg$, Cu $1.013{\pm}0.373mg/kg$, Fe $426.293{\pm}114.842mg/kg$, no Hg, Mn $0.109{\pm}0.082mg/kg$, Ni $0.122{\pm}0.068mg/kg$, Zn $3.584{\pm}1.270mg/kg$. 4. The concentration of Hazardous heavy metal (As, Cd, Co, Cr, Hg, Ni, Pb) within blood control group is searched $0.488{\pm}0.138\;mg/l$; experiment I group $0.432{\pm}0.080mg/l$, experiment II group $0.588{\pm}0.213mg/l$. In the concentration of non hazardous heavy metal(Cu, Fe, Mn, Zn) control group $101.409{\pm}6.832mg/l$; experiment I group $96.062{\pm}5.732\;mg/l$, experiment II group $125.139{\pm}044.820mg/l$. 5. Correlation among every metal in blood Zn and Cr was 0.87956 ; Cd and As -0.02316, Pb and As -0.08738, Ni and As 0.07824, Mn and As 0.07824, Mn and Cd 0.04999. Briefly under the injection of SipJeonDaeBo-decoction, this study was defined within safety in blood level by P.O. during 10 days.

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