• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.172-177
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• 1993

• Journal of Integrative Natural Science
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• v.1 no.3
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• pp.192-194
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• 2008

A series of non-free hydride reducing systems containing boron or aluminum atom, which possess no metal-hydride bond but an available hydrogen at a branched ${\beta}$-position, has been applied to the selective reduction (chemo--, regio-, and stereoselective reduction) of organic compounds. The systems, comprised of diisopinocampheylborane and diisobutylalane derivatives, exhibited almost perfect selectivities in the reduction of aldehydes and ketones. The characteristics features of this systems leading to a perfect transformation have been depicted in this report, especially in the 1) Reduction of ${\alpha}$,${\beta}$-Unsaturated Carbonyl Compounds to Allylic Alcohols via 1,2-Reduction, 2) Chemoselective Reduction between Structurally Different Carbonyl Compounds, and 3) Stereoselective Reduction of Cyclic Ketones.

• Fire Science and Engineering
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• v.32 no.2
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• pp.1-6
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• 2018

The combustion characteristics of cypress wood coated with boric acid (BA) and ammonium pentaborate (APB) were examined using a cone calorimeter according to the ISO 5660-1 standard. As a result, the combined specimens of boric acid and ammonium pentaborate (BA/APB) led to an improved fire performance index due to their synergistic effect. In addition, the total heat release values of the specimen coated with the boron compounds were 6.1~14.1% lower than that of the base specimen. The total smoke release rate (TSR) of the specimens coated with the boron compound decreased throughout the combustion process, except for BA/APB. The maximum concentration of carbon monoxide was reduced by 15.8~25.5%. In general, wood treated with flame retardants has a lower fire hazard.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.1
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• pp.10-19
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• 2020

Boron Neutron Capture Therapy (BNCT) has the advantage of selectively removing cancer cells ingesting boron compounds. In this study, the benefits for treatment time and boron compound injection dose were compared between current neutron sources and a high current neutron sources to be developed in near future. The time-activity curve (TAC) of GBM (Glioblastoma) for one bolus injection was obtained by applying modified 3 compartment model. The treatment time was determined for an accelerator-based neutron sources at the present time and a high current accelerator based neutron source to be developed in the near future. In the case of the double amount of IAEA-recommended neutron flux, the treatment time was shortened to 15 minutes. In the case of high current accelerators, which are five times the amount of IAEA-recommended neutron flux, the irradiation time is within 5 minutes. The use of a high current accelerator based neutron source in BNCT is advantageous in terms of treatment time. In addition, it can increase the efficiency of use of neutrons and reduce the boron compound injection dose to patients, thus reducing pharmacological toxicity.

• Korean Journal of Materials Research
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• v.25 no.12
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• pp.659-665
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• 2015

The self-propagating high temperature synthesis approach was applied to synthesize amorphous boron nano-powders in argon atmospheres. For this purpose, we investigated the characteristics of a thermally induced combustion wave in the $B_2O_3+{\alpha}Mg$ system(${\alpha}=1.0-8.0$) in an argon atmospheres. In this study, the exothermic nature of the $B_2O_3-Mg$ reaction was investigated using thermodynamic calculations. Experimental study was conducted based on the calculation data and the SHS products consisting of crystalline boron and other compounds were obtained starting with a different initial molar ratio of Mg. It was found that the $B_2O_3$ and Mg reaction system produced a high combustion temperature with a rapid combustion reaction. In order to regulate the combustion reaction, NaCl, $Na_2B_4O_7$ and $H_3BO_3$ additives were investigated as diluents. In an experimental study, it was found that all diluents effectively stabilized the reaction regime. The final product of the $B_2O_3+{\alpha}Mg$ system with 0.5 mole $Na_2B_4O_7$ was identified to be amorphous boron nano-powders(< 100 nm).

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.63-71
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• 2005

Equilibrium geometries, electronic structures, and energies of borocarbon clusters (binary compounds of carbon and boron), an unexplored class of molecules with highly unusual characteristics and potential for further development, have been investigated by means of B3LYP/6-311+G$^*$ density functional theory computations. A large number of B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ clusters with planar and non-planar monocyclic and polycyclic rings, as well as cage structures, have been systematically studied. Unexpectedly, planar forms are predicted not only to be the most stable structures, but also, in many cases, to have unprecedented planar heptacoordinate boron (p-heptaB) and planar heptacoordinate carbon (p-heptaC) arrangements. All these pheptaB and p-heptaC have 6π electrons and are aromatic according to the nucleus independent chemical shift (NICS). This novel bonding pattern is analyzed in terms of natural bond orbital (NBO) analysis. For virtually all possible B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ combinations, the p-heptaB arrangements are the more stable than other type structures.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.804-811
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• 2004

We have studied microwave extraction process of boric acid from one of calcium borate ores, colemanite. Calcium and boron have separated by addition of sulfuric acid, and calcium has been separated out as calcium sulfate. It was possible to extract boron with the smaller amount of sulfuric acid and with short heating time in microwave heating compared to conventional heating process. The products of boric acid was the same purity and thermal characteristic, but smaller in particle size.

• Korean Journal of Materials Research
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• v.14 no.4
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• pp.246-250
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• 2004

We have investigated the effects of boron added to Cu film on the Cu-Ti reaction and microstructural evolution of Cu(B) alloy film during annealing of Cu(B)/Ti/$SiO_2$/Si structure. The result were compared with those of Cu(B)/$SiO_2$ structure to identify the effects of Ti glue layers on the Boron behavior and the result grain growth of Cu(B) alloy. The vacuum annealing of Cu(B)/Ti/$SiO_2$ multilayer structure allowed the diffusion of B to the Ti surface and forming $TiB_2$ compounds at the interface. The formed $TiB_2$ can act as a excellent diffusion barrier against Cu-Ti interdiffusion up to $800^{\circ}C$. Also, the resistivity was decreased to $2.3\mu$$\Omega$-cm after annealing at $800^{\circ}C$. In addition, the presence of Ti underlayer promoted the growth Cu(l11)-oriented grains and allowed for normal growth of Cu(B) film. This is in contrast with abnormal growth of randomly oriented Cu grains occurring in Cu(B)/$SiO_2$ upon annealing. The Cu(B)/Ti/$SiO_2$ structure can be implemented as an advanced metallization because it exhibits the low resistivity, high thermal stability and excellent diffusion barrier property.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2274-2278
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• 2012

To test the efficiency of the BDD electrode for complete mineralization of organic wastewater, phenol and 2-chlorophenol (2-CP) were treated electrochemically with both an active Pt/Ti electrode and a nonactive boron doped diamond (BDD) electrode, respectively, in neutral aqueous medium. Aqueous solutions of both phenol and 2-chlorophenol were treated electrochemically using an in-house fabricated flow through electrochemical cell (FTEC). The experimental variables included current input, treatment time, and the flow rate of the solutions. Depending on the magnitude of the applied current and reaction time, the compounds were either completely degraded or partially oxidized to other intermediates. Removal efficiencies reached as high as 93.2% and 94.8% both at the Pt/Ti electrode and BDD electrode, respectively, at an applied current of 200 mA for a 3.0 hr reaction and a flow rate of 4 mL/min. The BDD electrode was much more efficient for the complete mineralization of phenol and 2-chlorophenol than the Pt/Ti electrode.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.49-57
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• 1995

At present the processes of boronizing have been mostly studied in a plasma from gaseous compounds containing the impregnating element and are in an industrial use. These have been investigated by a variety of works in a glow discharge with different mixture ratios of $B_2H_6$ and $H_2$ as well as $BCl_3$ and $H_2$. The active atomosphere has been diluted by Ar or some other inert gas in order to enhance control of boron potential and to reduce the ignition voltage of the glow discharge. The Control of gaseous atomosphere is essential to a boride layer in plamsa boronizing treatment. The boride formation is required to make the workpiece surface saturated with boron content. The present study considers the efficiency of plasma boronizing reactions and the morphology of boride layer under various plasma conditions