• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1154-1158
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• 2006

Anomalously high ionic mobilities of H+ and $OH^-$ are owing to the transfer of $H^+$ by the Grotthus chain mechanism. Molecular dynamics simulations for the system of 215 water including $OH^-$ ion at 298.15 K using the OSS2 model [J. Chem. Phys. 109, 5547 (1998)] as a dissociable water model with the use of Ewald summation were carried out in order to study the dynamics of $OH^-$ in water. The calculated ionic mobility of $OH^-$ is in good agreement with the experimental result and the Grotthus chain mechanism is fully understood.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.319-320
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• 2003

대기 중에서 HOx(OH, H $O_2$) 라디칼은 중요한 산화제로, 대류권내 광화학 반응에서 핵심적인 역할을 한다 이러한 OH 라디칼의 정확한 농도를 측정하는 것은 대기의 산화능력, 기후 변화 및 대기 중의 광화학 반응을 보다 정확히 이해하기 위해 필수적이다. 그러나 OH를 비롯한 HOx 라디컬의 농도 측정은 대기 내에 존재하는 양이 절대적으로 작고 (OH: $10^{6}$molecules $cm^{-3}$, H $O_2$: $10^{8}$molecules $cm^{-3}$), 반응성이 커서 수명이 짧기 때문에 측정에 많은 어려움이 따른다. (중략)

• Nutrition Research and Practice
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• v.1 no.3
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• pp.189-194
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• 2007

This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.382-383
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• 2003

해만가리비(Argopecten irradians)는 미국의 대서양 연안과 걸프만이 원산지로 중국에서는 1982년 미국에서 이식한 이래 많은 양식생산이 이루어지고 있으며, 우리나라에서는 1996년 국립수산과학원 남해수산연구소에서 새로운 양식품종으로 개발하고자 최초로 이식하여 실내에서 인공종묘생산으로 치패를 생산한 바 있다. 국내에서는 연구로는 동절기 성장(Oh and Jung, 1999), 밀도별 성장(Oh et al. 2000), 양식 생물학적연구(Oh, 2000), 수심별 성장(Oh et al., 2002) 생식주기(Oh et al., 2002), 선발효과(Oh et al., 2002)등에 관한 연구를 수행한 바 있으며, 외국에서는 산란 및 생식상태(Loosanoff and Davis, 1963; Taylor and Capuzzo, 1983; Hampson and Capuzzo. (중략)

• The Korean Journal of Applied Statistics
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• v.7 no.2
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• pp.113-130
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• 1994

The algorithm of Oh and Berger (1993) is extended to handle more general cases where the integrand $f(\theta)$ is not only multimodal but also skewed or has some undetected modes, each having curvature not much different from that of the nearest component. It runs Oh and Berger's algorithm in an iterative way, adding a component in each stage to the mixture importance function from previous stage for better approximation between $f(\theta)$ and the importance function.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.121-126
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• 2008

The effect of $Al(OH)_3$ on physical, thermal, and retardant property of rubber was studied. It was analyzed by statistical experimental design method with one way array to confirm the effect of factors. Physical characteristics, thermal pyrolysis temperature, and combustion time were considered as the properties. The amount of $Al(OH)_3$ addition was chosen as significant parameter. As the result of ANOVA analysis, thermal pyrolysis temperature increased and combustion time decreased with increasing of $Al(OH)_3$.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.60-64
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• 2006

has been synthesized using the layered organic-inorganic hybrids, Cu2(OH)3(CH3COO)·H2O as a precursor. Cubic Cu2O is synthesized by reducing Cu2(OH)3(CH3COO)·H2O with glucose in water at 75oC. The effects of precursor and glucose are investigated. The structure of Cu2(OH)3(CH3COO)·H2O plays an important role in preparing the uniform size of Cu2O.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.553-557
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• 2013

The stretching vibration of OH of ice Ih is studied by Car-Parrinello molecular dynamics in regarding the effect of mixed H/D contamination while the vibrational spectrum is considered by velocity-velocity autocorrelations of the sampled ensemble. When hydrogen atoms are immersed randomly into the deuterated ice, a typical vibrational frequency of OH stretching mode is observed to be similar to that from the pure $H_2O$ ice. When focusing on the correlation of isolated neighboring OH stretching, a narrower and blue shifted peak is observed at the high frequency range as a result of the screening from the complex many body correlations by $D_2O$ environment. It is also specifically related to the symmetric intermolecular correlations between neighboring OH stretching modes. More enhanced high frequency range can be explained by the expansion of such two body correlations to collective many body correlations among all possible OH stretching modes. This contribution becomes important when it involves in chemical interactions via excitation of such vibrational states.

• Journal of Aerospace System Engineering
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• v.7 no.4
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• pp.36-41
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• 2013

In order to improve incombustibility of EPDM(Ethylene propylene diene monomer)-based rubber, inorganic materials as $Al(OH)_3$ and $Sb_2O_3$ were added. The mechanical and thermal properties have been measured for vulcanized rubber loaded with different concentrations of $Al(OH)_3$ and $Sb_2O_3$. As inorganic material contents increases from 5phr to 30phr, the specific gravity and hardness increase while elongation at break decreases. This study performed incombustibility test and thermal analysis through TGA(Thermogravimetric Analyzer). As a results, incombustible and thermal properties of EPDM-based rubber were improved as $Al(OH)_3$ and $Sb_2O_3$ contents increase.

• Bulletin of the Korean Chemical Society
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• v.9 no.2
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• pp.101-105
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• 1988

The ab initio effective valence shell Hamiltonian method, based on quasidegenerate many-body perturbation theory, is generalized to calculate molecular properties as well as the valence state energies which have previously been determined for atoms and small molecules. The procedure requires the evaluation of effective operator for each molecular property. Effective operators are perturbatively expanded in powers of correlation and contain contributions from excitations outside of the multireference valence space. To demonstrate the validity of this method, calculations for dipole moments of several low lying valence states of OH, $OH^+$, and $OH^-$ to first order in the correlations have been performed and compared with configuration interaction calculations.