• Bulletin of the Korean Chemical Society
• /
• 제26권10호
• /
• pp.1525-1528
• /
• 2005

The synthesis and characterization of ${K_3[Ru(C_2O_4)3]{\cdot}4H_2O\;(C_2O_4}^{2-}$ = oxalato anoin) complex are described, and its redox properties (in buffer solution of pH = 12) have been investigated. This complex is used for in situ generation of oxoruthenates complexes which have been characterized by electronic spectroscopy. Reaction of ${K_3[Ru(C_2O_4)3]{\cdot}4H_2O$ with excess ${S_2O_8}^{2-}$ in molar KOH generates trans-${[RuO_3(OH)_2]^{2-}/S_2O_8}^{2-}$ reagent while with excess ${BrO_3}^-$ in molar $Na_2CO_3$ generates ${[RuO_4]^-/BrO_3}^-$ reagent. Avoiding the direct use of [$RuO_4$] the organic-soluble $(n-Pr_4N)^+[RuO_4]^-$, (TPAP) has been isolated by reaction of $K_3[Ru(C_2O_4)3]{\cdot}4H_2O$ with excess ${BrO_3}^-$ in molar carbonate and n-$Pr_4$NOH. In a mixture of $H_2O/CCl_4$ ruthenium tetraoxide can be generated by reaction of $K_3[Ru(C_2O_4)3]{\cdot}4H_2O$ with excess ${IO_4}^-$. The catalytic activities of oxoruthenates that have been made from $K_3[Ru(C_2O_4)3]{\cdot}4H_2O$ towards the oxidation of benzyl alcohol, piperonyl alcohol, benzaldehyde and benzyl amine at room temperature have been studied.

• 한국환경보건학회지
• /
• 제42권2호
• /
• pp.112-117
• /
• 2016

Objectives: In this study, we investigated the biodegradation rates of 8 perfluorooctanesulfonate (PFOS) alternatives synthesized at the at Changwon National University in comparison to those of PFOS potassium salt and PFOS sodium salt. Methods: A biodegradability test was performed for 28 days with microorganisms cultured in the good laboratory practice laboratory at the Korea Environment Corporation following the OECD Guidelines for the testing of chemicals, Test No. 301 C Results: While $C_5H_8F_3SO_3K$, $C_8F_{17}SO_3K$ and $C_8F_{17}SO_3Na$ were not degraded after 28 days, the 3 alternatives were biodegraded at the rates of 31.4% for $C_8H_8F_9SO_3K$, 25.6% for $C_{10}H_8F_{13}SO_3K$, 23.6% for $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, 20.9% for $C_{15}F_9H_{21}S_2O_8Na_2$, 15.5% for $C_{23}F_{18}H_{28}S_2O_8Na_2$, 8.5% for $C_{17}F_9H_{25}S_2O_8Na_2$ and 4.8% for $C_6H_8F_5SO_3K$. When the concentration was the same(500 mg/L), $C_{23}F_{18}H_{28}S_2O_8Na_2$ had the lowest tension with 20.94 mN/m, which was followed by $C_{15}F_9H_{21}S_2O_8Na_2$ (23.36 mN/m), $C_{17}F_9H_{25}S_2O_8Na_2$ (27.31 mN/m), $C_{25}F_{17}H_{32}S_3O_{13}Na_3$ (28.17 mN/m), $C_{10}H_8F_{13}SO_3K$ (29.77 mN/m) and $C_8H_8F_9SO_3K$ (33.89 mN/m). Having higher surface tension of 57.64 mN/m and 67.57 mN/m, respectively, than those of the two types of PFOS salts, $C_6H_8F_5SO_3K$ and $C_5H_8F_3SO_3K$ were found valueless as substitute for PFOS. Conclusion: The biodegradation test suggest that 6 compounds could be used as substitutes for PFOS. $C_{23}F_{18}H_{28}S_2O_8Na_2$ and $C_{15}F_9H_{21}S_2O_8Na_2$ were found to be the best substitutes based on biodegradation rate and surface tension, followed by $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, $C_8H_8F_9SO_3K$ and $C_{10}H_8F_{13}SO_3K$. $C_{17}F_9H_{25}S_2O_8Na_2$ was found to have relatively low value as an alternative but it still had a potential to substitute the conventional PFOS.

• 공업화학
• /
• 제4권2호
• /
• pp.291-299
• /
• 1993

생석회-규사-수계 및 시멘트 슬러지-규사-수계에서 1.13nm tobermorite를 수열합성하였다. 생석회-규사-수계의 경우 반응온도 $180^{\circ}C$, $CaO/SiO_2$의 몰비 0.4, 0.8에서 공히 양질의 tobermorite($5CaO{\cdot}6SiO_2{\cdot}5H_2O:C_5S_6H_5$)가 형성되었으나 $CaO/SiO_2$의 몰비 0.4일 때는 반응시간 6시간에서, 0.8일 때는 4시간에서 결정전이 현상이 관찰되었다. 그러나 시멘트 슬러지를 생석회 대신 전량 사용한 시멘트 슬러지-규사-수계는 동일한 몰비에서 반응시간 10시간 이내에 결정전이 현상이 나타나지 않았는데 이는 시멘트 슬러지로부터 용출되어 나온 알루미늄 이온의 지연작용으로 판단되며 생석회-규사-수+알루미늄계에서 확인되었다. 알루미늄 분말의 첨가량이 0.8에서 3.0%로 증가함에 따라 결정은 보다 넓고 평평하게 형성되었다. 또한 동일한 반응시간 내에서 재결정화 현상이 관찰되지 않았다.

• 동력기계공학회지
• /
• 제18권1호
• /
• pp.51-56
• /
• 2014

In this paper, the performance of the $CO_2-C_2H_6-N_2$ cascade liquefaction cycle with respect to temperature differences in the LNG heat exchangers is analyzed theoretically using HYSYS software and then compared the COP(coefficient of performance) of the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ and $CO_2-N_2O-N_2$. In comparison of COP of three cycles, the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ showed the highest COP. And the liquefaction cycle using $CO_2-C_2H_6-N_2$ and $CO_2-N_2O-N_2$ presented the second and third highest COP, respectively. In case of COP, the $C_3H_8-C_2H_4-C_1H_4$ cascade liquefaction cycle yields better COP. But, in terms of the environment and maintain, it is confirmed that the cascade liquefaction cycle using $CO_2-C_2H_6-N_2$ provides favorable characteristics.

• 한국결정학회지
• /
• 제6권2호
• /
• pp.98-102
• /
• 1995

1-Ethyl-1,4-dihydro-7-methyl-1,8-naphthyridin-4-one-3-carboxylic acid [Nalicixic Acid]의 분자 및 결정구조를 X-선 회절법으로 연구하였다. 이 결정의 분자는 C12H12N2O3, 단사정계이고 공간군은 P21/c이다. 단위포상수 a=8.910(2)Å, b=13.145(3)Å, c=9.370(3)Å 이며, β=100.06(2)°, V=1080.6Å, T=293K, Z=4이다. 구조해석에 사용한 X-선은 CuKα선(λ=1.5418Å)을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R값은 [F0>4σ(F0)]인 1555개의 독립회절반점에 대해 R=0.055이었다. 이 분자는 한 개의 내부수소결합 O(17)-H(17)…O(14)를 가지고 있다 [2.525(2)Å, 144.3(10)°].

• 한국표면공학회지
• /
• 제50권4호
• /
• pp.296-300
• /
• 2017

NiO nanofibers with Au nanoparticles were synthesized by sol-gel and electrospinning techniques, in which the reduction process by ultraviolet exposure is included for the growth of Au nanoparticles in the electrospinning solution. FE-SEM(Field Emission Scanning Electron Microscopy), TEM(Transmission Electron Microscopy) revealed that the synthesized nanofibers had the diameter of approximately 200 nm. X-ray diffraction showed the successful formation of Au-decorated NiO nanofibers. Gas sensing tests of Au-decorated NiO nanofibers were performed using reducing gases of CO, and $C_6H_6$, $C_7H_8$, $C_2H_5OH$. Compared to as-synthesized NiO nanofibers, the response of Au-loaded NiO nanofibers to CO gas was found to be about 3.4 times increased. On the other hand, the response increases were only 1.1-1.3 times for $C_6H_6$, $C_7H_8$, and $C_2H_5OH$.

• 통합자연과학논문집
• /
• 제8권4호
• /
• pp.250-257
• /
• 2015

The crystal structure of the potential active 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile ($C_{19}H_{16}N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=6.6869 (8) ${\AA}$, b=15.8326 (19) ${\AA}$ and c= 15.237 (2) ${\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=100.663^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...N and C-H...O hydrogen bond interaction.

• Environmental Analysis Health and Toxicology
• /
• 제31권
• /
• pp.2.1-2.4
• /
• 2016

Objectives In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. Methods Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). Results While $C_8F_{17}SO_3Na$, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for $C_{15}F_9H_{21}S_2O_8Na_2$, 8.4% for $C_{17}F_9H_{25}S_2O_8Na_2$, 22.6% for $C_{23}F_{18}H_{28}S_2O_8Na_2$, and 23.6% for $C_{25}F_{17}H_{32}O_{13}S_3Na_3$. Conclusions $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, $C_{23}F_{18}H_{28}S_2O_8Na_2$, and $C_{15}F_9H_{21}S_2O_8Na_2$ were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.

• 한국결정성장학회지
• /
• 제20권4호
• /
• pp.178-184
• /
• 2010

마이크로 웨이브 연소합성법(microwave-assistant combustion method)를 이용하여 $12CaO{\cdot}7Al_2O_3$(C12A7) 분말을 성공적으로 제작하였고, $H_2$ 가스 분위기에서의 후열처리를 통하여 C12A7:H 제작에 성공하였다. 분말의 합성 여부 와 결정성 확인 및 분말 하소 시 온도에 따른 반응 분석을 위하여 X-ray diffraction(XRD) 및 TG-DSC 분석을 시행하였다. 또한, 후 열처리 후 C12A7 cage 내부의 자유산소 이온이 수소 이온으로 치환되었는지 확인하기 위하여 TG-MS 분석을 시행하였고, $289.5^{\circ}C$에서 H와 $H_2$ 가스가 방출되는 것이 확인되었으므로, H 이온이 cage 내부로 치환된 것을 확인시켜준다. 성공적으로 치환된 C12A7:H 를 홀 측정기(Hall measurement)를 이용하여 전도성을 측정하여 본 결과 $1000^{\circ}C$, Ar/H=8:2의 분위기에서 8h 이상 처리된 C12A7:H의 경우 상온(300 K)에서 $10^2{\Omega}{\cdot}cm$의 비저항 값을 나타내었다.

• 한국결정학회지
• /
• 제6권1호
• /
• pp.27-35
• /
• 1995

1-tert-butoxycarbonyl-4-[N-(tert-butoxycarbonyl)-N-(ethoxycarbonylmethyl)amino]-3-phenylsulfonylpyrrolidind [C24H36O8N2S;이하 BEP]의 분자 및 결정구조를 X-선 회절법으로 연구하였다. 이 결정의 분자는 C24H36O8N2S, 삼사정계이고 공간군은 P1이다. 단위세포 길이는 a=11.363(8)Å, b=11.589(6)Å, c=11.013(10)Å,α=95.32(6)°,β=98.64(7)°,γ=79.57(5)°,V=1406.8(18)Å3, t=293K, Z=2이다. 구조해석에 사용한 X-선은 CuKα선(λ=1.5418Å)을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R값은 F≥4 σ(F)인 3621개의 회절반점에 대하여 R=9.78% 이었다.