• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.85-86
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• 2006

A high Tc superconducting with a nominal composition of $Bi_2Sr_2Ca_2Cu_3O_y$ was prepared by the citarte method. The solid precursor produced by the dehydration of the gel at $120^{\circ}C$ for 12h is not in the amorphous state as expected but in a crystalline state. X-ray diffraction peaks of nearly the same angular position as the peaks of high Tc phase were observed in the precursor. After pyrolysis at $400^{\circ}C$ and calcination at $840^{\circ}C$ for 4h, the (001)peak of the high Tc phase was cleary observed. Experimental results suggest that the intermediate phase formed before the formation of the superconducting phase may be the most important factro in determining whether it is easy to form the high Tc phase or not, because the nucleation barriers of the two superconducting phase may be altered by the variation of the crystal structures of those intermediate phase.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.31-35
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• 1991

Three isomers of damascenone, odorous terpenic ketones, have been synthesized conveniently from a same starting material, ethyl 2,6,6-trimethyl-4-oxo-2-cyclohexene-1-carboxylate(1), which was easily available by the acid-catalyzed condensation of mesityl oxide or acetone with ethyl acetoacetate. ${\alpha}$-Damascenone(7) was prepared by converting the enone ester 1 into the corresponding tosylhydrazone(4), followed by treating with 4 molar equiv of allyllithium. ${\beta}$-Damascenone(12) was synthesized by chemoselective reduction of 1 with sodium borohydride/cerium chloride to give corresponding allylic alcohol 8, conversion of 8 into acetate 9, and thermal decomposition of 9 with DBU to afford ethyl ${\beta}$-safranate(10), followed by reaction with an excess amount of allyllithium. ${\gamma}$-Damascenone(15) was obtained by dehydration of 8 with boric acid to furnish ${\gamma}$-safranate(13), followed by treatment with 2 molar equiv of allyllithium.

• 한국표면공학회지
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• 제51권6호
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• pp.360-364
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• 2018

A facile method to fabricate freestanding CuO nanoleaves and CuO nanowires-based films was demonstrated. $Cu(OH)_2$ nanoleaves and nanowires were prepared by a hydrolysis reaction in aqueous solution including pyridine and NaOH with the tailored concentrations at room temperature. The films of freestanding CuO nanoleaves and CuO nanowires can be successfully obtained via the simple vacuum infiltration following a thermal dehydration reaction. The morphologies and crystallinity of the $Cu(OH)_2$ nanoleaves/nanowires and CuO nanoleaves/nanowires were characterized by XRD, SEM, TEM and FT-IR. The films fabricated with freestanding CuO nanoleaves and nanowires in this study may be applicable for building high-efficiency organic binder-free devices, such as gas sensors, batteries, photoelectrodes for water splitting and so on.

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1197-1202
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• 2005

The Ln(III) complexes with picrate ligand, $[Sm(Pic)_2(H_2O)_6]Pic{\cdot}6H_2O$, 1, and $[Ho(Pic)(H_2O)_7](Pic)_2{\cdot}3H_2O$, 2, have been synthesized and their crystal structures are analyzed by X-ray diffraction methods. Complex 1, crystallizes in the monoclinic $P2_1/n$ space group and complex 2 in the triclinic P-1 space group. In complex 1, two picrate ligands coordinate to the Sm(III) ion, one of them in the bidentate fashion. There are one picrate anion and six water molecules in the crystal lattice. The nine-coordinated Sm(III) ion forms a slightly distorted tricapped trigonal prism. In complex 2, only one picrate ligand coordinates to the metal ion as a monodentate. There are two picrate anions and three water molecules in the crystal lattice. The eight-coordinated Ho(III) ion forms a distorted bicapped trigonal prism. Based on the results of the TG-DTG and DSC thermal analysis, it was analyzed that the lanthanide picrate complexes 1 and 2 are thermally decomposed in three distinctive stages, the dehydration, the picrate decomposition, and the formation of the metal oxide.

• 공업화학
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• 제21권4호
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• pp.424-429
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• 2010

본 연구는 유기발광디바이스용(OLED) 녹색발광재료인 6-알킬-3-크로몬알데히드(2,2-디알킬)하이드라존 유도체의 합성에 관한 것으로서, 유도체들은 탈수축합반응으로 합성되었다. 이들은 전자흡인성의 6-알킬-3-크로몬알데히드류와 전자공여성의 2,2-디알킬하이드라존류의 공액구조를 가지고 있다. 합성된 물질들은 각각 FT-IR, $^1H$-NMR 스펙트럼으로부터 그의 구조적 특성을 확인하였고, 융점, 수득률에 의하여 열적 안정성, 반응성을 확인하였으며, 여기스펙트럼과 발광스펙트럼으로부터 자외가시광과 발광특성을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권4호
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• pp.471-474
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• 1994

Five experimental groups with five adult male rats in each, were exposed to 20, 35, 40 and $45^{\circ}C$ air temperature for 50-70 minutes, and to $50^{\circ}C$ for 30-50 minutes, respectively. Food and drinking water were not permitted during the exposure. Blood samples were obtained by heart puncture immediately after the thermal treatment. All the rats were hyperthermic (p<0.01) as compared to the controls ($20^{\circ}C$). Hyperthermia was associated with hypoglycemia which was significant (p<0.01) at 45 and $50^{\circ}C$ exposures. Plasma levels of GOT and GPT declined at 35 and $40^{\circ}C$ reaching the lowest (p<0.05) level at $45^{\circ}C$, while at $50^{\circ}C$ GOT level was elevated by 45% but GPT was normal as compared to the controls. Differences between groups were significant (p<0.01) for GOT and insignificant for GPT. Hematocrit value increased significantly (p<0.01) at 45 and $50^{\circ}C$, indicating hemoconcentration. It could be concluded that severe heat stress (45 and $50^{\circ}C$) resulted in critical hyperthermia, hypoglycemia, disturbed liver function, body dehydration, and hemoconcentration leading to death.

• 멤브레인
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• 제9권3호
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• pp.170-177
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• 1999

Polysulfone을 술폰화하여 물-부탄올 용액의 분리를 위한 투과증발용 비대칭막을 제조하였다. 술론화제로는 chlorosulfoneic acid-trimethyulchlorosilane을 반응시킨 후 이용하였다. FT-IR과 $^1H$-NMR을 이용하여 치환여부를 살펴보았고 술폰화정도는 역적정법과 $^1H$H-NMR을 이용하여 구하였다. DSC와 TGA를 이용하여 열적특성변화를 알아보았다. 비대칭막을 제조하기 위하여 N-methyl-2-pyrrolidone(NMP)rhkdiethyleneglycol dimethyl ether (DGDE)의 혼합용매를 사용하였다. SEM을 이용하여 단면과 skinlayer 의 구조변화를 살펴보았다. 한 연구에서 제조한 비대칭막은 dense film에 비하여 물에 대한 선택도는 거의 변화가 없고 투과유량은 약 80배 정도 증가하였다.

• 한국분말재료학회지
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• 제5권3호
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• pp.199-209
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• 1998

A new low melting inorganic binder, monoclinic $HBO_2$, has been developed for Selective Laser Sintering (SLS) of alumina powder by dehydration process of boron oxide powder in a vacuum oven at $120^{\circ}C$. It led to better green SLS parts and higher bend strength far green and fired parts compared to other inorganic binders such as aluminum and ammmonium phosphate. This appeared to be due to its low viscosity and better wettability of the alumina particle surface. A low density single phase ceramic, aluminum borate ($Al_{18}B_4O_{33}$), and multiphase ceramic composites, $A_{12}O_3-A_{14}B_2O_9$, were successfully developed by laser processing of alumina-monoclinic $HBO_2$ powder blends followed by post-thermal processing; both $Al_{18}B_4O_{33}$ and $A_{14}B_2O_9$ have whisker-like grains. The physical and mechanical properties of these SLS-processed ceramic parts were correlated to the materials and processing parameters. Further densification of the $A_{12}O_3-A_{14}B_2O_9$ ceramic composites was carried out by infiltration of colloidal silica, and chromic acid into these porous SLS parts followed by heat-treatment at high temperature ($1600^{\circ}C$). The densities obtained after infiltration and subsequent firing were between 75 and 80% of the theoretical densities. The bend strengths are between 15 and 33 MPa.

• 공업화학
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• 제20권6호
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• pp.670-674
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• 2009

본 연구는 유기발광디바이스용(OLED) 녹색형광물질인 3-크로몬알데히드(2,2-이치환)하이드라존 유도체의 합성에 관한 것으로서, 유도체들은 탈수축합반응으로 합성되었다. 이들은 전자흡인성의 3-크로몬알데히드류와 전자공여성의 2,2-이치환하이드라존류의 공액구조를 가지고 있다. 합성한 물질은 각각 FT-IR, $^1H-NMR$ 스펙트럼으로부터 그의 구조적 특성을 확인하였고, 융점, 수득률에 의하여 열적 안정성, 반응성을 확인하였으며, 여기스펙트럼과 발광스펙트럼으로부터 자외가시광과 발광특성을 확인하였다.

• Applied Science and Convergence Technology
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• 제23권4호
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• pp.187-191
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• 2014

Indium oxide ($In_2O_3$) nanorods (NRs) which can be expected to increase the device performance in various electronic and electrochemical applications were prepared on carbon fibers via an electrochemical deposition (ED) method. During the ED, the indium hydroxide ($In(OH)_3$) NRs were well grown and firmly attached onto the carbon fibers. After that, they were changed into $In_2O_3$ by dehydration through a thermal annealing. The morphological and structural properties were investigated using field-emission scanning electron microscope images. The crystallinity of as-prepared sample was evaluated by X-ray diffraction. The Fourier transform infrared results confirm that the functional groups are present in the $In_2O_3$ NRs. This facile process of metal oxide nanostructures on carbon fiber can be utilized for flexible electronic and energy related applications.