• Archives of Pharmacal Research
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• v.21 no.6
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• pp.793-795
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• 1998

• Analytical Science and Technology
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• v.25 no.6
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• pp.339-344
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• 2012

In this research, hydride generation in HPLC-ICPMS for the selenium speciation was investigated. Chemical and photochemical vapor generation techniques were compared for the effective generation of selenium vapour. $HBr/KBrO_3$ was used for the chemical reduction and a UV lamp was used for the photochemical reduction. It was found out that the photochemical reduction was more effective than the chemical reduction in all of selenium species studied. The optimum conditions for the generation of vapour are 0.4% KI, 2.5% $NaBH_4$, and 1.0 M HCl. The enhancement factor using a photochemical hydride generation was from 6.3 to 16.7 times for inorganic and organic selenium species.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1808-1846
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• 2011

From 1975 to 2011, for thirty six years, the author and his collaborators have developed a variety of reducing and hydroborating agents, and applied them to organic synthesis, which involves the 1,2-reduction of ${\alpha}$,${\beta}$-unsaturated carbonyl compounds, stereoselective reduction of cycloalkanones, regioselective ring-opening of epoxides, partial reduction of carboxylic acid derivatives to aldehydes, regioselective addition to carbon-carbon multiple bonds, etc. by utilizing metal hydrides and the newly-devised the Meerwein-Ponndorf-Verley (MPV) type reagents. Such developments provide a new synthetic methodology making possible valuable selective reductions and hydroborations, not practical previously.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1879-1883
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• 2011

The electronic structure and bonding in $Ti_2Pd$ and $Pd_2Ti$ alloys with and without hydrogen as an interstitial atom were studied by performing extended Huckel tight-binding band calculations. The hydrogen absorption near an octahedral site is found to be a favorable process in $Ti_2Pd$ rather than in $Pd_2Ti$. In metal hydrides, the metal-hydrogen bonding contribution is crucial to the stability of the system. The stronger interaction of hydrogen with Ti atoms in $Ti_2PdH_2$ than with Pd atoms in $Pd_2TiH_2$ is analyzed by perturbation theory.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.3
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• pp.101-109
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• 1997

We propose a new concept of hydrogen absorbing alloy, "Laves phase related BCC solid solution". It was firstly found among the phases tormed in multicomponent nominal $AB_2$ alloys which consisted of Zr and Ti for the A metal site and 5A, 6A and 7A transition metals for the B metal sites. In these alloys a BCC solid solution often coexisted with a Laves phase. It showed stability of hydrides and reaction kinetics almost identical to intermetallics such as Laves phase alloys. We prepared an almost pure "Laves phase related BCC solid solution" and found that it had a large hydrogen capacity (more than 2 mass%) and fast hydrogen absorption and desorption kinetics at ambient temperature and pressure. This new hydrogen absorbing alloy may open a new era of hydrogen related application such as hydrogen vehicles.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.422-428
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• 1988

In this study we have investigated the effects of Mm, MmH and $MmH_2$ on the matrix development in cast iron, The conclusive summary is as follows: The spheroidal graphite was observed when 0.5wt.% or more of mischmetal was added and the matrix was of ledeburite structure, but bull's eye structure was not observed. On the other hand, the bull's eye structure was observed when 0.25wt.% of MmH, or 0.25wt.% to 0.5wt.% of $MmH_2$ was added. Above limit of the additives, the matrix changed into ledeburite structure. As the hydrogen content of mischmetal compound increased from MmH, the range of additives to obtain bull's eye structure expanded. This reveals the significant effect of mischmetal hydride on matrix development in cast iron and the possibility of practical use of the additives.

• Journal of the Korean Chemical Society
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• v.16 no.5
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• pp.261-264
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• 1972

The cubic force constants of the binary hydrides, LiH, BeH, BH, CH, NH and OH are evaluated by use of the one center function of Bishop et. al. The results are reasonably good. The master formula suggested in the previous report of the present author is found relatively insensitive to the crudities of the wave function.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.55-61
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• 1986

Phosphosilicate glass(PSG) films have been used as fusable deposited dielectrics in silicon gate MOS integrated circuits. But in this experiment BPSG(borophosphosilicate glass) will be optimized for more efficient utilization of the reactants. The BPSG films were deposited on silicon wafers by the oxidation of the hydrides at 430$^{\circ}$C in conventional atmospheric-pressure chemical-vapor-deposition (CVD) systems. Physical and chemical properties of CVD BPSG films have been characterized both for as-deposited and for fused films The. relationship between deposited BPSG film composition and infra-red absorption solution etch rate and fusion temperature is discussed and examples of BPSG composition that can be fused at 900~95$0^{\circ}C$ and 800~85$0^{\circ}C$ are given. In addition to having lower fusion temperature than PSG films BPSG films have lower as-deposited intrinsic tensile stress and low aqueous chemical etch rate they have been considered for applications where these characteristics are advantageous.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.1153-1171
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• 2010

Hydrogen is the most abundant element in the universe. Although hydrogen can produce three times more energy than gasoline and seven times than coal, the most challenging problem in utilizing hydrogen as energy carrier is its storage problem. In contrast to the liquid hydrocarbon, hydrogen can not be stored or transported easily and safely because of its extremely low boiling point(21K). Recently scientists have made a tremendous achievement in storing hydrogen capacity in solid state materials such as carbon based and metal organic frameworks materials as well as metal hydrides. In this review the author reviewed the status of the hydrogen storage technologies in solid state, the advantages and disadvantages in each category of materials and the future prospects of hydrogen storage.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2927-2929
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• 2009

The hydricities of d$^6$ metal hydride complexes in aqueous solution were calculated by using density functional theoretical (DFT) calculations coupled with a Poisson-Boltzmann (PB) solvent model. Hydricity describes the hydride donor ability of the metal-hydrogen bond, which assists in the study of the mechanism of many catalytic processes and chemical reactions that involve transition metal hydrides. The calculation scheme produced hydricity values that were in good agreement with experimental estimation. The inclusion of a water molecule as a weakly bound ligand to five-coordinate metal complexes gave an improved correlation result.