• Korean journal of food and cookery science
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• v.27 no.5
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• pp.523-530
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• 2011

This study was conducted to investigate antimicrobial, antioxidant and anticancer activities of Opuntia humifusa (OH) petal extracts. The methanol and hexane extracts of OH petals showed their highest antimicrobial activity against Clostridium perfringens. The OH petal butanol fraction had the best antioxidative peroxynitrite scavenging activity among OH petal extracts. The DPPH scavenging activity of OH petals was lower than the peroxynitrite scavenging effect. The hexane and methanol fractions at a concentration of 200 ${\mu}g$/mL inhibited proliferation >80% in four kinds of human cervical cancer cells(B16F10, HepG2, HT-29 and MCF-7). In particular, the anticancer effect against B16F10 human skin cancer cells at the same concentration was higher than that in the other cancer cells.

• Journal of the Korean Ceramic Society
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• v.28 no.1
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• pp.67-73
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• 1991

Monodispersed PZT fine particles were obtained from the condition which 0.2Pb (OC3H7)2/EtOH, 0.108Zr(OC4H9)4/EtOH and 0.092 Ti (OC2H5)4/EtOH were refluxed for 5 hrs at 76$^{\circ}C$ and hydrolyzed with 0.1-0.4 H2O/EtOH. The monodispersed particle was amorphous and crystallized to the tetragonal PZT phase when heated at $600^{\circ}C$. Particle size was about 0.55${\mu}{\textrm}{m}$ in 0.3 H2O/EtOH and 0.3${\mu}{\textrm}{m}$ in other cases. Relative density of sintered body at 90$0^{\circ}C$ and 100$0^{\circ}C$ was 93.5% and 98%, respectively.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.75-78
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• 2002

CNTs have been grown by the thermal CVD process in which $C_{2}H_{2}$ gas was deposited on the Fe - $Al(OH)_3$ mixture pretreated by mechanochemical treatment with a high energy mixer mill. As the duration time of grinding fer $Fe-(Al(OH)_3$ mixture by the mixer mill increased, amorphous $Al(OH)_3$ and more smaller Fe particles agglomerated into spheres. With unground and ground mixtures of $Fe-Al(OH)_3$, CNTs were grown at $700^{\circ}C$. As a result, CNTs grown on ground mixtures have more uniform diameter and morphology than those of unground mixture. The characterization of $Fe-Al(OH)_3$ mixture and as-grown CNTs were done by XRD, SEM and TEM.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.50.1-50.1
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• 2009

셀룰로오스를 Ca(OH)2와 Ni(OH)2를 Pot에 넣고 동시에 밀링 공정을 실시한 후, 열을 가함으로써 수소를 얻었다. X-ray diffraction (XRD), thermogravimetry/ mass spectrometry (TG/MS), gas chromatography (GC) 장비를 이용해 수소 발생량 및 촉매의 역할에 관하여 실험하였다. 촉매 Ni(OH)2를 대신한 NiO 또는 Ni를 사용했을 경우 사용된 촉매에 따른 수소의 발생량의 차이를 보였는데 이는 촉매의 사이즈가 수소 발생량과 관련이 있음을 보여주었다. 한편, Ca(OH)2를 대신하여 Li(OH)를 사용하였을 때 수소 발생 온도가 약$400\sim500\;^{\circ}C$ 범위에서 $350\sim400\;^{\circ}C$의 범위로 낮아져 보다 낮은 온도에서 수소 회수가 가능하였다. 이때 발생한 CO와 CO2는 수 ppm정도로 적은 양이었다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.428-429
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• 2006

Aluminum hydroxides were synthesized by a simple electrolytic reaction of aluminum plates. The aluminum monohydroxide, boehmite(AlO(OH)), was predominantly formed by the application of an electrical potential above 30V, while the mixture of the bayerite$(Al(OH)_3)$ and boehmite(AlO(OH)) phases were formed below 20V. The boehmite has a clear fibrous structure which is controlled on a nanometer scale. On the contrary, the bayerite consists of the typical hourglass or semi-hourglass shaped coarse crystals as a result of an aggregation of the various crystals stacked together. The specific surface area of the boehmite nanofiber was remarkably high, reaching about $300m^2/g$.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.285-290
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• 2006

As an alternative method to solve air pollution problem and difficulty of pulp bleaching of kraft pulping process, NaOH-Urea pulping was applied. The properties of NaOH-Urea pulp were compared to those of NaOH and kraft pulps. Addition of urea in low alkali charges retarded delignification rate compared to NaOH pulping. But, in high alkali application, delignification was significantly enhanced not from the addition of urea but from the high alkalinity. It was disclosed that urea did not participate on delignification reaction by the experiment using lignin model compound. Compared to paper strengths at the same level of sheet density, NaOH-Urea pulp gave as almost same breaking length and tensile index as those of kraft pulp. Especially tensile energy absorption and burst index were higher than those of kraft pulp.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.929-934
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• 1996

The electrochemistry and the reaction of non-μ-oxo dimer-forming [5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinato] manganese(Ⅲ) chloride [(Cl8TPP)MnⅢCl] with tetraethylammonium hydroxide in water [-OH(H2O)] have been investigated by electrochemical and spectroscopic methods under anaerobic conditions. The stronger autoreduction of (C18TPP)MnⅢCl by -OH(H2O) in comparison with (Me12TPP)MnⅢCl by -OH(CH3OH) in MeCN is explained as the influence of electronic effects on substituted phenyl groups bonded to meso-position of porphyrin ring and the positive shift of reduction potential (-0.11 V) for (C18TPP)MnⅢCl. The autoreduction of manganese(Ⅲ) porphyrin to manganese (Ⅱ) by this process is only observed when one axial position is occupied by a ligating solvent and OH- coordinates the other axial site. The results are discussed in relation to the mechanisms for the reduction of manganese(Ⅲ) porphyrin.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.72.2-72.2
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• 2019

The hydroxyl radical (OH) sky emission lines arise from the Earth's mesosphere, and they serve as a major source of the sky background in the infrared. With IGRINS, the observed line strength show non-negligible variation even within a few minutes of time scale, making its subtraction difficult. Toward the aim better sky subtraction in the IGRINS pipeline, we present 1) improved identification of sky lines in H and K band and 2) improved method of subtracting sky background. Using the recent line list of Brooke et al. (2015), we have detected ~500 OH doublets from upper vibrational level between 2 and 9 and maximum upper J level of 25. In particular, we found that a significant fraction of unidentified lines reported by Oliva et al. (2015) are indeed OH lines resulting from transitions between different F levels. With the extended line identification, we present an improved method of sky subtraction. The method, based on the method of Noll et al. (2014), empirically accounts non-LTE level population of OH molecules.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.47-52
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• 1973

Korean bentonite was treated with aqueous NaOH solution under the reaction conditions such as concentration of NaOH, 0.5-6N; ratio of $Na_{2}O$ to $SiO_2$, 1-4; reaction time, 2-30 days; reaction temperature, $70^{\circ}C-90^{\circ}C$. The products were examined by X-ray diffraction patterns. When it was treated with 2N NaOH at $70^{\circ}C$, zeolite species $P_1$ was formed with good yield. In higher concentration and at higher temperature than above, zeolite species $P_1$ was converted to hyeroxysodalite. Together with these crystals, some faujasite type zeolite, sodium A zeolite, mordenite type zeolite etc. was formed depending upon reaction conditions.

• Advances in nano research
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• v.1 no.2
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• pp.93-103
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• 2013

An ultrasonic-mediated assisted stepwise method has been developed for depositing transparent ZnO films from aqueous solution. Rinsing in low ethylene glycol temperature was easy to produce intermediate phase of $Zn(OH)_2$, rinsing in $120^{\circ}C$ ethylene glycol was observed the diffraction peak of intermediate $Zn(OH)_2$ in early report, the rinsing temperature plays an important role in the process of $Zn(OH)_2$ phase transformed to ZnO, high rinsing temperature actually improved the intermediate phase. However, the effect of rinsing on the intermediate phase is yet to be understood clearly. The effect of different rinsing procedures, involving either of or a combination of successive ionic layer adsorption and reaction (SILAR) and ultrasonic-assisted rinsing, prior to hydrolysis in ethylene glycol was found to improve the occurrence $Zn(OH)_2$ in ZnO thin films. In the zinc complex ($[Zn(NH_3)_4]^{2+}$) solution, excess ($[Zn(NH_3)_4]^{2+}$) absorbed in glass substrate transformed incompletely to ZnO and exist as $Zn(OH)_2$ phase in thin films. In films deposited at low temperature, rinsing procedure is applied to improve excess $Zn(OH)_2$ and obtain smoother transparent thin films.