• Journal of the Mineralogical Society of Korea
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• v.12 no.2
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• pp.77-90
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• 1999

Characteristics and variations of chemical compositions in Co-rich crusts occurred in the EEZ of the Republic of Marshall Islands were reviewed. Correlation coefficient analysis, hierarchical cluster analysis, and Q-mode factor analysis for 62 samples were done in this study. All data were selected and gathered from the open file report of the cooperative cruise done by United States Geological Survey with Scripps Institute of Oceanography, University of Hawaii or Korea Ocean Research Development Institute. The average of crust thickness. Co content, and Ni content of 62 samples from the 21 seamounts were 30mm, 0.58 wt% and 0.40%, respectively. The mineral phases and associated elements assigned by correlation coefficients, cluster analysis and Q-mode factor analysis are following four. 1) CFA: P, Ca, CO2, Y, Sr: 2) Mn-oxide mineral: As, Mn, Co, Na: 3) Al-silicate mineral: Pd,Si, Al, Cu, Fe: 4) PGE-bearing mineral: Rh, Pt, Ir.

• Journal of Ginseng Research
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• v.7 no.1
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• pp.74-79
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• 1983

Effect of soil moisture on content and partition of mineral nutients in panax ginseng (2 years old) was investigated. Similarity was found between N and p, Ca and Mg, K and Fe. Mn and Zn were quite different each other and from others. Nutrient partition was affected more by nutrient content than by dry matter. Under suboptimal moisture condition partition to shoot was inhibited in order of Mg, Zn, Ca, Mg, N and P while accelerated in odor of Fe. K and Mn. Under supraoptimal moisture condition Partition to shoot was inhibited in order of Zn, Fe, K, and Ca, while accelerated in order of Mg, N, Mn and p.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.53-53
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• 2002

• Journal of the Microelectronics and Packaging Society
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• v.20 no.3
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• pp.53-57
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• 2013

Although the lowering of Ag content in Sn-3.0Ag-0.5Cu is known to improve the mechanical shock reliability of the solder joint, it is also known to be detrimental to the solderbility. In this study, the quaternary alloying effect of In and the minor alloying effects of Mn and Pd on the solderability, thermal cycling and mechanical shock reliabilities of the low Ag content Sn-1.2Ag-0.7Cu solder were investigated using board-level BGA packages. The solderability of Sn-1.2Ag-0.7Cu-0.4In was proved to be comparable to that of Sn-3.0Ag-0.5Cu but its thermal cycling reliability was inferior to that of Sn-3.0Ag-0.5Cu. While the 0.03 wt% Pd addition to the Sn-1.2Ag-0.7Cu-0.4In decreased the solderability and reliabilities of solder joint, the 0.1 wt% Mn addition was proved to be beneficial especially for the mechanical shock reliability compared to those of Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.5Cu compositions. It was considered to be due that the Mn addition decreased the Young's modulus of low Ag content Pb-free solders.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.141-149
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• 1997

L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders were prepared by both GNP(Glycine-Nitrate Process) and solid state reaction method in various of calcination temperature(800-1000.deg. C) and time in air. Also, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contacts on YSZ(Yttria-Stabilized Zirconia) substrate were prepared by screen printing and sintering method as a function of sintering temperature(1100-1450.deg. C) in air. Sintering behaviors have been investigated by SEM(Scanning Electron Microscope) and porosity measurement. Compositional and structural characterization were carried out by X-ray diffractometer and ICP AES(Inductively Coupled Plasma-Atomic Emission Spectrometry) analysis. Electrical characterization was carried out by the electrical conductivity with linear 4 point probe method. As the calcination period increased in solid state reaction method, L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ phase increased. Although L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ single phase was obtained only for 48hrs at 1000.deg. C, in GNP method it was easy to get single and ultra-fine L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ powders with submicron particle size at 650.deg. C for 30min. The particle size and thickness of L $a_{0.7}$S $r_{0.3}$Mn $O_{3}$ cathode contact by solid state reaction method did not change during the heat treatment, while those by GNP method showed good sintering characteristics because initial powder size fabricated from GNP method is smaller than that fabricated from solid state reaction method. Based on enthalpy change from thermodynamic data and ICP-AES analysis, it was suggested to make cathode contact in composition of (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$ Mn $O_{3}$ which have little second phase (L $a_{2}$Z $r_{2}$ $O_{7}$) for high efficient solid oxide fuel cells applications. As (L $a_{0.7}$S $r_{0.3}$)$_{0.91}$Mn $O_{3}$ cathode contact on YSZ substrate was sintering at 1250.deg. C the temperature that liquid phase sintering did not occur. It was possible to obtain proper cathode contacts with electrical conductivity of 150(S/cm) and porosity content of 30-40%.m) and porosity content of 30-40%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.267-271
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• 1983

The southern parts varieties have shown higher content of Oleic acid, Linoleic acid, Vitamin A, Alcaloid, Ca, P and Fe than northern parts Varieties. The $N.\;P_2O_5\;and\;K_2O content of narrow leaf were higher than wide leaf, on the other hand the Ca, Mg, Fe and $SiO_2$ content of wide leaf were higher than narrow leaf. The content of $N, \;P_2O_5, \;K_2O$ have shown higher in first yellow leaf date, the content of Ca has shown higher in first falling leaf date and the content of Mn and Cu content have shown higher in second new leaf date.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.1
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• pp.11-21
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• 1997

$ZrV_{0.7}Mn_{0.5}Ni_{1.2}$ alloy is attractive for anode material in Ni/MH secondary battery because of its large hydrogen storage capacity in gas-solid reaction and long cycling durability in KOH electrolyte. In this work, in order to further improve the discharge performance of this alloy electrode, the alloy was annealed by optimal condition which is for 12 hours at $1000^{\circ}C$. The alloy annealed under optimal condition had higher rate capability and discharge capacity than as-cast one. The microstructure of the as-cast and annealed alloy was investigated by scanning electron microscopy and energy dispersive spectroscopy. Ni content in the matrix was increased, being this homogenized after annealing. Additionally, The measurement of the surface area by B.E.T. analysis showed that there was little difference as-cast and annealed alloy. Therefore, improvement in the rate capability of the annealed alloy is due to increase of Ni content in the matrix.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1523-1526
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• 2001

To study the secretion of trace elements during early lactation, twelve lactating Murrah buffaloes were selected from the herd of the institute. The buffaloes were divided into two groups of six each. Buffaloes of group I were not injected and served as control. Buffaloes of group II received oxytocin injection (2.5 I.U.) intramuscularly for a period of five days for let down of milk. Milk samples were collected from both groups of buffaloes five days before, during and after the administration of oxytocin. Aliquots of milk samples from each buffalo were composited in proportion to their milk yield and used for analysis of trace elements in milk. In both the groups of buffaloes Cu, Mg, Fe, Zn and Mn contents did not vary significantly between animals. However, Ca levels varied significantly (p<0.01) between animals. Administration of oxytocin influenced (p<0.01) Cu, Mg, Zn, Fe and Mn secretion in milk. However, Ca secretion was not affected by oxytocin administration. Secretion of these elements also varied significantly during different days of the study. Zinc content of milk in the control group also varied significantly (p<0.01) during different days and periods of study indicating thereby no effect of oxytocin. The study indicated that administration of oxytocin increases Cu and Mn content and decreases Mg, Fe and Zn content without altering the Ca concentration of milk.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.135-143
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• 1993

Chemical compositions of sphalerites from 25 gold and/or silver deposits in central Korea were obtained with an electron probe microanalyzer. The FeS contents of sphalerites depend generally upon the assemblage of associated iron sulphides (pyrite and/or pyrrhotite) especially. The sphalerites coexisting with pyrrhotite show a narrow range of FeS variation, but the sphalerites associated with pyrite and/or pyrrhotite have the variable and wide range of FeS contents. The sphalerites from Au-dominant deposits, which vary considerably in each deposit, are generally characterized by high CdS content and low MnS content. On the contrary, the sphalerites from Ag-dominant and Au-Ag deposits tend to be characterized by relatively high MnS and very low CdS content. Based upon the mineralogy, fluid inclusions and stable isotope data, the Au-dominant deposits were formed under higher temperature and deeper depth than the Ag-dominant and Au-Ag deposits. The results suggest the possibility that the diverse sources and evolution of ore fluid at the time of ore deposition are responsible for the deposition of Cd and Mn components in sphalerites.

• Corrosion Science and Technology
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• v.20 no.4
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• pp.196-203
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• 2021

To improve corrosion resistance and reduce the hydrogen uptake of 22MnB5, up to 5% Mg was added to the AlSi coating of 22MnB5. After hot-stamping and electrocoating were done on the metallic-coated specimen, the surface characteristics of the steel, hydrogen uptake content, and corrosion resistance were examined by transmittance electron microscopy, thermal desorption spectrometry, cyclic corrosion testing, and electrochemical impedance spectroscopy. Mg was investigated as MgO on the surface layer after hot-stamping while it existed as Mg₂Si before hot-stamping. The total hydrogen content of 22MnB5 was decreased along with the Mg content. However, there was no difference at 0.2 wt% or more. When a small amount of Mg was added, the coating corrosion resistance was decreased, but when it was added at around 1.0 wt%, the greatest corrosion resistance increase was seen. However, when 3 wt% or more was added excessively, the corrosion resistance was decreased. MgO on the surface was considered to suppress H uptake by the AlSi melting solution and increase the barrier effect of the coating.