• Journal of Surface Science and Engineering
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• v.56 no.5
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• pp.320-327
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• 2023

In this study, the nickel hydroxide (Ni(OH)₂) electrode for supercapacitor was prepared via hydrothermal method. Based on the nickel (Ni) foam, the electrode does not require any additional binder material or post-processing. Nickel nitrate (Ni(NO₃)₂) and hexamethylenetetramine (C₆H₁₂N₄) were used for synthesis, and the synthesis condition was 12 hours at 80 ℃. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) were used to analyze the structural characteristics of the electrode, and it shown that the nickel hydroxide was successfully prepared after only the one-step hydrothermal synthesis. The electrochemical properties were analyzed through the half-cell test. The prepared electrode shown a pair of oxidation/reduction peaks, indicating that the driving method included the redox reaction on the electrode surface. After the charge/discharge test, the specific capacitance was calculated as the value of 438 F/g at 3 A/g.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.399-402
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• 2000

The reduction of chip area and delay is important purpose of Scheduling in High-Level Synthesis. This paper presents a scheduling approach with component selection. After obtaining a initial schedule taking only single-functional u-nits, the component selection of our approach attempts the reduction of chip area and/or delay by the selection more suitable components in a component library using Simulated Annealing.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1641-1648
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• 2003

New and facile synthetic routes for preparation of optically active norephedrine, norpseudoephedrine and cathinone with high optical purities via double asymmetric induction by employing asymmetric reduction of 2-N-protected amino (or azido)-1-phenylpropanone and 2-methanesulfonyloxy-1-phenylpropanone with CBS-catalyzed-borane and $^dIpc_2BCl$ as chiral reducing agents are described.

• Bulletin of the Korean Chemical Society
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• v.16 no.9
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• pp.805-808
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• 1995

Diacetone-D-glucose was converted into 5-azido-6-O-benzoyl-3-O-benzyl-5-deoxy-1,2-O-isopropylidene-α-D-glucofuranose. After removal of isopropylidene and benzoyl protecting groups, hydrogenation performed reduction of azide and subsequent cyclization by reductive amination to give 3-O-benzyl-1-deoxy nojirimycin in high yield. The second azide group was introduced on 2-carbon by selective substitution reaction, and reduction of azide to amino group gave titled compound.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.314-321
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• 1996

Isoxazolidine derivatives 7 and 8 were synthesized from N-benzyl-C-(2-benzyloxyethyl)nitrones by 1,3-dipolar cycloaddition with ethyl crotonate. The isoxazolidine derivatives were converted to β-amino acid esters 9a and 9b by reduction with zinc in acetic acid. The β-amino acid esters were reacted with methylmagnesium bromide to give the 2-azetidinones (13a, 13b). The benzyl group of 2-azetidinones were removed by Birch reduction. The products were oxidized with PDC to give 3-[1-(t-butyldimethylsilyloxy)ethyl]-4-carboxymethyl-2-azetidinone derivatives (2a, 2c).

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.184.2-184.2
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• 2003

Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. The role of oxycholesterol including 2, 5(R)-2, 6-hydroxycholesterol is a potent inhibitor of cholesterol biosynthesis in vitro as it is an effective inhibitor of HMG-Coa reductase. Some new polyhydroxylated sterols were showed potent cytotoxicity to cancer cells. And it has also been chown to be an inhibitor of DNA synthesis, In order to synthesize the various oxy derivatives, we tried to positionselective and reagentselective epoxidation and reduction of cholesterol derivatives. (omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.290.1-290.1
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• 2016

Grapehen, a single atomic layer of graphite, has been in the spotlight and researched in vaious fields, because its fine mechanical, electrical properties, flexibility and transparence. Synthesis methods for large-area graphene such as chemical vaper deposition (CVD) and mechanical, chemical exfoliation have been reported. In particular, chemical exfoliation method receive attention due to low cost process. Chemical exfoliation method require reduction of graphene oxide in the process of exfoliation such as chemical reduction by strong reductant, thermal reduction on high temperature, and optical reduction via ultraviolet light exposure. Among these reduction methods, optical reduction is free from damage by strong reductant and high temperature. However, optical reduction is economically infeasible because the high cost of short-wavelength ultraviolet light sorce. In this paper, we make graphene-oxide and lanthanoid ion mixture aqueous solution which has highly optical absorbency in selective wevelength region. Sequentially, we synthesize reduced graphene oxide (RGO) using the solution and visible laser beam. Concretely, graphene oxide is made by modified hummer's method and mix with 1 ml each ultraviolet ray absorbent Gd3+ ion, Green laser absorbent Tb3+ ion, Red laser absorbent Eu3+ ion. After that, we revivify graphene oxide by laser exposure of 300 ~ 800 nm layser 1mW/cm2 +. We demonstrate reproducibility and repeatability of RGO through FT-IR, UV-VIS, Low temperature PL, SEM, XPS and electrical measurement.

• Earthquakes and Structures
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• v.2 no.1
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• pp.65-88
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• 2011

A new method for the seismic design of plane steel moment resisting frames is developed. This method determines the design base shear of a plane steel frame through modal synthesis and spectrum analysis utilizing different values of the strength reduction (behavior) factor for the modes considered instead of a single common value of that factor for all these modes as it is the case with current seismic codes. The values of these modal strength reduction factors are derived with the aid of a) design equations that provide equivalent linear modal damping ratios for steel moment resisting frames as functions of period, allowable interstorey drift and damage levels and b) the damping reduction factor that modifies elastic acceleration spectra for high levels of damping. Thus, a new performance-based design method is established. The direct dependence of the modal strength reduction factor on desired interstorey drift and damage levels permits the control of deformations without their determination and secures that deformations will not exceed these levels. By means of certain seismic design examples presented herein, it is demonstrated that the use of different values for the strength reduction factor per mode instead of a single common value for all modes, leads to more accurate results in a more rational way than the code-based ones.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.86-92
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• 2002

A short synthesis of novel prostanoids, 12-epi-carbacyclins 3 and 24, has been accomplished using palladium chemistry as a key step. The silyl enol ether 10a prepared through organopalladium chemistry has been allowed to react with 1-octen-3-one in the presence of $Pd(OAc)_2$ to give compound 12 in a single step. The unusual chemo- and stereoselective reduction of the ${\alpha},{\beta}$-unsaturated ketone in 12 has been effected with (S)-BINALH. Subsequent desilylation and Wittig reaction have provided the Subsequent desilylation and Wittig reaction have provided the $PGI_2$ analogues 3 and 24.

• Journal of Powder Materials
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• v.10 no.5
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• pp.337-343
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• 2003

Nanostructured Cu-$Al_2O_3$ composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + $Al_2O_3$, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-$Al_2O_3$, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/$Al_2O_3$ composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/$Al_2O_3$ composite by the conventional internal oxidation process.