• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.971-975
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• 1994

Cross sections and recoil properties have been measured for the fragments produced in the interaction of silver with 40 MeV/nucleon $^{14}N$ ions using off-line ${\gamma}$-ray spectroscopy. The data were used to obtain the isobaric-yield distribution, the mass yield distribution, and the fractional momentum transfer. The values of forward-to-backward ratios were measured to be very large, indicating that substantial momentum transfer occurs at this energy regime. The results are compared with other studies of the interaction of silver with intermediate-energy heavy ions.

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1172-1175
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• 1997

Calcium isotopic ratios are precisely measured by removing isobaric interferences originated from water in the plasma. Liquid Ar cryogenic trap combined with membrane desolvator could eliminate backgrounds at m/z 42 and 44. Slow drift of ICP-MS is corrected by the frequent running of the standards. It is found necessary to separate Ca from the sample matrix using Ca oxalate precipitation technique. Currently, the RSD is 0.5-1.0% for 2 minutes of measurement but is expected to be improved if the measurement time is increased. The technique was applied to 42Ca enriched baby fecal samples and successfully determined 42Ca/44Ca ratio changes.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.371-381
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• 2006

New proteomic techniques have been pioneered extensively in recent years, enabling the high-throughput and systematic analyses of cellular proteins in combination with bioinformatic tools. Furthermore, the development of such novel proteomic techniques facilitates the elucidation of the functions of proteins under stress or disease conditions, resulting in the discovery of biomarkers for responses to environmental stimuli. The ultimate objective of proteomics is targeted toward the entire proteome of life, subcellular localization biochemical activities, and the regulation thereof. Comprehensive analysis strategies of proteomics can be classified into three categories: (i) protein separation via 2-dimensional gel electrophoresis (2-DE) or liquid chromatography (LC), (ii) protein identification via either Edman sequencing or mass spectrometry (MS), and (iii) proteome quantitation. Currently, MS-based proteomics techniques have shifted from qualitative proteome analysis via 2-DE or 2D-LC coupled with off-line matrix assisted laser desorption ionization (MALDI) and on-line electrospray ionization (ESI) MS, respectively, toward quantitative proteome analysis. In vitro quantitative proteomic techniques include differential gel electrophoresis with fluorescence dyes. protein-labeling tagging with isotope-coded affinity tags, and peptide-labeling tagging with isobaric tags for relative and absolute quantitation. In addition, stable isotope-labeled amino acids can be in vivo labeled into live culture cells via metabolic incorporation. MS-based proteomics techniques extend to the detection of the phosphopeptide mapping of biologically crucial proteins, which ale associated with post-translational modification. These complementary proteomic techniques contribute to our current understanding of the manner in which life responds to differing environment.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.140-144
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• 2018

Isotopic analyses of plutonium and low-enriched uranium mixtures with particle sizes of $0.6-3.3{\mu}m$ were performed using thermal ionization mass spectrometry with a continuous heating method to verify its effectiveness for the accurate analysis of minor isotopes without sample pretreatment. The mixed particles used in this study were prepared from a mixed solution of plutonium (SRM 947) and uranium (U010, $^{235}U$ 1% enriched) reference materials. The isotope ratios for plutonium in the individual mixed particles, including $^{238}Pu/^{239}Pu$, $^{241}Pu/^{239}Pu$ as well as $^{240}Pu/^{239}Pu$, and $^{242}Pu/^{239}Pu$, were in good agreement with the certified values despite the isobaric interference of $^{238}U$ and $^{241}Am$. The isotope ratios for uranium in the mixed particles also agreed well with the certified values within the range of error. However, the isotope ratios for minor isotopes, such as $^{234}U$ and $^{236}U$, in the particles with diameters of less than approximately $1.8{\mu}m$ could not be measured because numbers of $^{234}U$ and $^{236}U$ atoms in analyzed particles are too low. These results indicate that thermal ionization mass spectrometry with a continuous heating method is applicable for the analysis of trace amounts of plutonium isotopes, including $^{238}Pu$ and $^{241}Pu$, despite the presence of the respective isobars $^{238}U$ and $^{241}Am$ in the microsamples.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.222-228
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• 2018

Benzene is one of the most widely used basic materials in the petrochemical industry. Generally, benzene exists as a mixture with alcohols rather than as a pure substance. Further, the alcohols-added mixtures usually exhibit an azeotropic composition. In this context, knowledge of the phase equilibrium behavior of the mixture is essential for its separation and purification. In this study, the vapor-liquid equilibrium data were measured in favor of a recirculating VLE apparatus under constant pressure for the 1 - propanol / benzene system. The measured vapor - liquid equilibrium data were also correlated by using the UNIQUAC and WILSON models and the thermodynamic consistency test based on the Gibbs/Duhem equation was followed. The results of the phase equilibrium experiment revealed RMSEs (Root Mean Square Error) and AADs (Average Absolute Deviation) of less than 0.05 for both models, indicating a good agreement between the experimental value and the calculated value. The results of the thermodynamic consistency test also confirmed through the residual term within ${\pm}0.2$.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.401-411
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• 2023

Many studies have been conducted to improve technology for semen cryopreservation in pigs. However, computer-assisted analysis of sperm motility and morphology is insufficient to predict the molecular function of frozen-thawed semen. More accurate expression patterns of boar sperm proteins may be derived using the isobaric tags for relative and absolute quantification (iTRAQ) technique. In this study, the iTRAQ-labeling system was coupled with liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis to identify differentially expressed CM10-fractionated proteins between fresh and frozen-thawed boar semen. A total of 76 protein types were identified to be differentially expressed, among which 9 and 67 proteins showed higher and lower expression in frozen-thawed than in fresh sperm samples, respectively. The classified functions of these proteins included oxidative phosphorylation, mitochondrial inner membrane and matrix, and pyruvate metabolic processes, which are involved in adenosine triphosphate (ATP) synthesis; and sperm flagellum and motile cilium, which are involved in sperm tail structure. These results suggest a possible network of biomarkers associated with survival after the cryopreservation of Duroc boar semen.

• The Journal of the Petrological Society of Korea
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• v.8 no.3
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• pp.183-202
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• 1999

The Sobeaksan Gneiss Complex in the Punggi area is composed of mainly mignatitic gneiss, porphyroblastic gneiss, garnet granitic gneiss and biotitie granitic gneiss. Metamorphic grade increase gradually from the amphibolite facies of northwestern part to the granulite facies of southwestern part in the study area. Representative mineral assemblage in the amphibolite facies is biotite-muscovite-K-feldspar-plagioclase$\pm$garnet$\pm$epidote, needle shape or fibrous sillimanite occur in transitional zone from the amphibolite facies to the granulite facies. In the granulite facies, the garnet-Opx granulite shows garnet-orthopyroxene-biotite-plagioclase, the metabasite shows clinopyroxene-plagioclase$\pm$hornblende$\pm$orthopyroxene$\pm$garnet and the migmatitic gneiss shows garnet-biotite-sillimanite-cordierite$\pm$spinel as representative mineral assemblage. Retrograde metamorphism after the granulite facies metamorphism made corindum and andalusite in the migmatitic gneiss and the thin layer garnet between clinopyroxene and plagioclase in the metabasites. The peak P-T conditions of the migmatitic gneiss and the garnet-Opx granulite are $916^{\circ}C$/6.6 kb and $826^{\circ}C$/6.3 kb, respectively. The P-T condition of biotite and plagioclase inclusion, which indicates the progressive condition of the granulie facies, within garnet is $866^{\circ}C$/7.5 kb and that of rim composition of garnet and biotite is $726^{\circ}C$/4.6 kb, which infer the clockwise P-T path of the granulite facies metamorphism. The temperatures caculated by the rim composition of garnet and biotite in the migmatitic gneiss and garnet granitic gneiss have a wide range of $556-741^{\circ}C$, which indicate that the retrograde metamorphism after the granulite facies metamorphism has effected differently. It is difficult to determine the P-T condition of the biotite granitic gneiss because less occurrence and higher spessartine content of garnet. The P-T condition of the thin layered garnet between clinopytoxene and plagioclase in the metabasite is $635-707^{\circ}C$/4.1-5.3 kb. This texture indicates the isobaric cooling(IBC) condition of the retrogressive metamorphism. As a result, the metamorphic evolution of the Punggi area has undergone the isobaric cooling after the granulite facies metamorphism which has undergone the clockwise P-T path.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1697-1704
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• 2007

We present results for transport properties of diatomic fluids by isothermal-isobaric (NpT) equilibrium molecular dynamics (EMD) simulations using Green-Kubo and Einstein formulas. As the molecular elongation of diatomic molecules increases from the spherical monatomic molecule, the diffusion coefficient increases, indicating that longish shape molecules diffuse more than spherical molecules, and the rotational diffusion coefficients are almost the same in the statistical error since random rotation decreases. The calculated translational viscosity decreases with the molecular elongation of diatomic molecule within statistical error bar, while the rotational viscosity increases. The total thermal conductivity decreases as the molecular elongation increases. This result of thermal conductivity for diatomic molecules by EMD simulations is again inconsistent with the earlier results of those by non-equilibrium molecular dynamics (NEMD) simulations even though the missing terms related to rotational degree of freedom into the Green-Kubo and Einstein formulas with regard to the calculation of thermal conductivity for molecular fluids are included.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.630-633
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• 2005

Some gases can be formed into hydrate by physical combination with water under appropriate temperature and pressure condition. Besides them, it was found that the pore size of the sediments can affect the formation and dissociation of hydrate. In this study, formation temperatures of carbon dioxide and methane hydrate have been measured using isobaric method to investigate the effects of flow rates of gases on formation condition of hydrate in porous rock samples. The flow rates of gases were controlled using a mass flow controller. To minimize Memory effect, system temperature increased for the dissociation of gas hydrates and re-established the initial saturation. The results show that the formation temperature of hydrate decreases with increasing the injection flow rate of gas. This indicates that the velocity of gas in porous media may act as kinds of inhibitor for the formation of hydrate.

• International Journal of Air-Conditioning and Refrigeration
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• v.12 no.4
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• pp.176-183
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• 2004

Systematic methods to calculate thermodynamic properties of carbon dioxide, HFC-134a and HCFC-22 are presented. First, application of a basic method to identify the saturation state with given temperature or pressure is attempted and the feasibility of auxil­iary equations is tested. Next, detailed procedures are suggested to tell a phase when tem­perature/pressure and another property are specified. Finally the Newton-Raphson method is applied to calculate unknown thermodynamic properties fixing the state with the two inde­pendent properties specified. The procedures described here are utilized to develop a computer program, which is used to find the relation between temperature and pressure with maximum isobaric heat capacity for super-critical carbon dioxide.