• KSBB Journal
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• v.5 no.4
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• pp.355-363
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• 1990

Methanol-utilizing bacterium isolated from sewage samples in Seoul showed optimal temperature and pH of $33^{\circ}C$ and 7.1 for growth, respectively. The maximum specific growth rate was $0.42hr^{-1}$. The minimum medium composition was reconstituted depending on the surplus and the deficit of each component in the basal medium at steady state. The optimal composition was given as(g/l); Methanol 40, $(NH_4)_2\;SO_42, \;KH_2PO_4\;1.5, \;K_2HPO_4\;0.2, \;H_3PO_4\;0.79, \;Na_2HPO_4{\cdot}12H_2O\;0.15, \;MgSO_4{\cdot}7H_2O\;1.5, \;FeSO_4{\cdot}7H_2O\;0.034, \;MnSO_4{\cdot}4H_2O\;0.005, \;CuSO_4{\cdot}5H_2O\;0.0027, \;CaCl_2{\cdot}2H_2O\;0.25, \;ZnSO_4{\cdot}7H_2O\;0.007, \;(NH_4)_6\;Mo_7O_{24}{\cdot}4H_2O\;0.00048, \;H_3BO_3\;0.00068, \;CoCl_2\; 0.00024$ Under the continuous culture with optimum medium the maximum cell productivity was 3.8g/1/hr at dilution rate $0.23hr^{-1}$. Maximum cell concentration and its protein content were 19.5g/l and 70% at dilution rate of $0.1hr^{-1}$, respectively.

• Transactions on Electrical and Electronic Materials
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• v.2 no.2
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• pp.37-41
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• 2001

Photo catalytic characteristics of nano-sized TiO$_2$ powder with rutile phase produced using homogeneous precipitation process at low temperatures (HPPLT) were compared with those of commercial P-25 powder by Degussa Co. The TiO$_2$ powder by HPPLT showed very higher photoactivity in the removal rate, showing lower pH values in the solution, than the P-25 powder when eliminating metal ions such as Pb and Cu from aqueous metal-EDTA solutions. This can be inferred the more rapid photo-oxidation or -reduction of metal ions from the aqueous solution, together with relatively higher efficiencies in the use of electron-hole pair formed on the surface of TiO$_2$ particle, under UV light irradiation. Also, in the view of the TiO$_2$ particle morphology, compared to the well-dispersed spherical P-25 particle, the agglomerated TiO$_2$ particle by HPPL T consists of acicular typed primary particle with the thickness ranged of 3∼7 nm, which would be more effective to the photocatalytic reactions without electron-hole recombination on the surface of the TiO$_2$ particle under the UV light irradiation. It is, therefore, thought that the higher photo activity of the rutile TiO$_2$ powder by HPPLT in the aqueous solutions resulted from having its higher specific surface area as well as acicular shape primary particle with very thin thickness.

• Korean Journal of Crystallography
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• v.9 no.2
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• pp.114-119
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• 1998

Imperatorin, 9-[(3-methyl-2-butenyl)oxy]-7H-furo[3,2-g][1]benzopyran-7-one의 분자 및 결정구조를 X-선 회절법으로 연구하였다. 이 결정의 분자식은 C16H14O4, 결정계는 삼사정계이고 공간군은 P이다. 단위포상수는 a=11.818(1) , b=11.906(1) , c=11.059(1) 이며, α=96.32(1)o, β=90.74(1)o, γ=64.88(1)o, V=13.993(2) 3, T=293 K, Z=4이다. 구조해석에 사용한 X-선은 CuKα선(λ=1.5418 )을 사용하였다. 구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R 값은 F0>4σ(F0)인 3951개의 독립회절데이타로 356개 파라메타에 대해 R=7.02%이다.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.799-809
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• 2006

Hydrobromic acid salts of new N, N, O tridentate ligands containing phenol, 2-[(2-Methylamino- ethyl- amino)-methyl]-phenol(H-MMP. 2HBr), 5-Bromo-2-[(2-Methylamino-ethylamino)-methyl]-phenol (Br- MMP. 2HBr), 5-Chloro-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Cl-MMP. 2HBr), 5-Methyl-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Me-MMP. 2HBr), 5-Methoxy-2-I(2-Methylamino-ethylamino)- methyl]-phenol(MeO- MMP. 2HBr) and. 1-[(2-Methylamino-ethylamino)- methyl]-naphthalen-2-ol(Nap- MMP. 2HBr) were synthesized. The synthesized ligands were confirmed by C. H. N. atomic analysis, UV-visible and IR spectroscopies, $^1$H NMR, $^{13}$C NMR and mass analysis. The potentiometry study revealed that the proton dissociation constants(logK$_n^H$) of the synthesized ligands and stability constants (logK$_{ML}$, logK$_{LM2}$) of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions occurred in three steps and the order of the calculated overall proton dissociation constants(log$\beta_p$) and stability constants (logK$_{ML}$) of ligands was Br-MMP. 2HBr < Cl-MMP 2HBr < H-MMP. 2HBr < Nap-MMP. 2HBr < Me-MMP. 2HBr < MeO-MMP. 2HBr. The order showed a similar trend to that of Hammett substituent constants($\delta_p$). The synthesized ligands usually form 2:1(ML$_2$) complexes with transition metal ions. The order of the stability constants of each transition metal ions was Co(II) < Ni(II) < Cu(II) ;> Zn(II) ;> Cd(II) ;> Pb(II).

• Clean Technology
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• v.27 no.1
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• pp.69-78
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• 2021

Vegetable oils, such as palm oil and cashew nut shell liquid (CNSL), are used as major raw materials for bio-diesel in transportation and bio-heavy oil in power generation in South Korea. However, due to the high unsaturation degree caused by hydrocarbon double bonds and a high content of oxygen originating from the presence of carboxylic acid, the range of applications as fuel oil is limited. In this study, hydrotreating to saturate unsaturated hydrocarbons and remove oxygen in mixed bio-oil containing 1/1 v/v% palm oil and CNSL on monometallic catalysts (Ni and Cu) and bimetallic catalysts (Ni-Zn, Ni-Fe, Ni-Cu Ni-Co, Ni-Pd, and Ni-Pt) was perform under mild conditions (T = 250 ~ 400 ℃, P = 5 ~ 80 bar and LHSV = 1 h-1). The addition of noble metals and transition metals to Ni showed synergistic effects to improve both hydrogenation (HYD) and hydrodeoxygenation (HDO) activities. The most promising catalyst was Ni-Cu/��-Al2O3, and in the wide range of the Ni/Cu atomic ratio of 9/1~1/4, the conversion for HYD and HDO reactions of the catalysts were 90-93% and 95-99%, respectively. The tendency to exhibit almost constant reaction activity in these catalysts of different Ni/Cu atomic ratios implies a typical structure-insensitive reaction. The refined bio-oil produced by hydrotreating (HDY and HDO) had significantly lower iodine value, acid value, and kinetic viscosity than the raw bio-oil and the higher heating value (HHV) was increased by about 10%.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.405-409
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• 2003

The effect of substitution of Gd ions for Ca ions in the B $i_{1.84}$P $b_{0.34}$S $r_{1.91}$(C $a_{1-x}$ G $d_{x}$)$_{2.03}$ C $u_{3.06}$ $O_{ 10+{\delta}}$/ (x=0.0~0.06) was investigated by measuring x-ray diffraction patterns, lattice constants, do resistivity and Hall effect. We found the solubility limit of Gd in the 110 K phase to be x < 0.015. Within the solubility limit, the c-axis seemed to decrease with increasing x. In the region of the 110 K single phase, the critical temperature $T_{c}$ gradually decreased with an increasing the Gd concentration x, corresponding to a small change of the carrier concentration.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.6
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• pp.507-513
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• 2000

This study was conducted to investigate the shelf life of beef stored in antimicrobial pottery during 12days storage at 4'C and Five kinds of antimicrobial potteries were prepared with antimicrobial materials such as TiO$_2$, Ag (NO$_3$)$_2$, Cu(NO$_3$)$_2$ and Zn(NO$_3$)$_2$. In changes of color during storage, Hunter's L- and b-value of beef were not changed, but Hunter's a-value was low significantly. The pH of beef meats were low at 6 days, but were added from 6 days. TBA value of beef in "A" pottery containing TiO$_2$ 1% and "C" Pottery containing TiO$_2$ 0.5%, Cu(NO$_3$)$_2$ were lower than "B", "D" and "I" pottery. VBN contents of beef in "A", "B", "C", "D" and "I" Pottery stored during 12 days were 9.8, 12.5, 9.3, 11.9 and 13.7mg%, respectively. In changes of total plate count of beef during storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.g storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.ttery were superior.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.271.1-271.1
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• 2013

Titania is usually used in sun-screens, tooth paste, and other daily used objects as a pigment. However, scientists have focused on titania as photocatalyst due to its excellent activities. By fabricating vanadium doped TiO2 and CuOx co-catalyzed TiO2 nano-size filter, the degradation level of the volatile organic compound (VOC) concentration was tested using 365nm UV LED as light source in a closed chamber. Main purpose for this test is to evaluate the activities of various catalysts for degrading the VOCs which are detrimental to human body and toluene and p-xylene were chosen in the VOC removal test. Target gas materials were injected into the test chamber with dry air as carrier gas which was flowed into the gas washer bottle filled with liquid form of VOC substance. When the VOC gas flows into the chamber, it is circulated by 200 mm fan in order to contact with the set-up filter on the aluminum holder. Target gas concentration in the chamber was monitored using VOC detector (miniRae3000, Raesystems) which was also placed inside the chamber. With the measured concentration, the VOC degradation efficiency and the degradation rate were evaluated and used to compare the catalytic activities.

• Korean Journal of Metals and Materials
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• v.49 no.9
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• pp.699-707
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• 2011

P122 steel, with a composition of Fe-10.57%Cr-1.79%W-0.96Cu-0.59Mn was arc-welded and oxidized between $600^{\circ}C$ and $800^{\circ}C$ in air for up to 6 months. The oxidation rates increased in the order of the base metal, weld metal, and heat-affected zone (HAZ), depending on the microstructure. The scale morphologies of the base metal, weld metal, and HAZ were similar because it was determined mainly by the alloy chemistry. The scale consisted primarily of a thin $Fe_2O_3$ layer at $600^{\circ}C$ and $700^{\circ}C$ and an outer $Fe_2O_3$ layer and an inner ($Fe_2O_3$, $FeCr_2O_4$)-mixed layer at $800^{\circ}C$. The microstructural changes resulting from heating between $600^{\circ}C$ and $800^{\circ}C$ coarsened the carbide precipitates, secondary Laves phases, and subgrain boundaries in the matrix, resulting in softening of the base metal, weld metal, and HAZ.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.695-701
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• 2013

To understand how reactivity between reinforcing nanoparticles and aqueous solution affects electrodeposited Cu thin films, two types of commercialized cerium oxide (ceria, $CeO_2$) nanoparticles were used with copper sulfate electrolyte to form in-situ nanocomposite films. During this process, we observed variation in colors and pH of the electrolyte depending on the manufacturer. Ceria aqueous solution and nickel sulfate ($NiSO_4$) aqueous solutions were also used for comparison. We checked several parameters which could be key factors contributing to the changes, such as the oxidation number of Cu, chemical impurities of ceria nanoparticles, and so on. Oxidation number was checked by salt formation by chemical reaction between $CuSO_4$ solution and sodium hydroxide (NaOH) solution. We observed that the color changed when $H_2SO_4$ was added to the $CuSO_4$ solution. The same effect was obtained when $H_2SO_4$ was mixed with ceria solution; the color of ceria solution changed from white to yellow. However, the color of $NiSO_4$ solution did not show any significant changes. We did observe slight changes in the pH of the solutions in this study. We did not obtain firm evidence to explain the changes observed in this study, but changes in the color of the electrolyte might be caused by interaction of Cu ion and the by-product of ceria. The mechanical properties of the films were examined by nanoindentation, and reaction between ceria and electrolyte presumably affect the mechanical properties of electrodeposited copper films. We also examined their crystal structures and optical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy.