• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.888-894
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• 1997

Two hulled and two hull-less barley varieties were investigated for ${\beta}-glucan$ enrichment. Hull-less barleys contained higher levels of total ${\beta}-glucan$ than hulled barleys, and were thus suitable as starting materials for preparing ${\beta}-glucan-rich$ fractions. Particularly, a waxy type (Suweon-291) of hull-less barley was found to have high soluble dietary fiber content containing primarily ${\beta}-glucan$, compared to the other non-waxy barley varieties. ${\beta}-Glucan$ content of barley during pearling process was measured, and the highest value was observed at the pearling yield of approximately $70{\sim}75%$. The pearled barley grains were ground and sieved to yield ${\beta}-Glucan$ enriched fractions containing up to 22% ${\beta}-glucan$. In the meanwhile, whole barley samples were directly milled by $B{\ddot{u}}hler$ mill to produce bran, shorts, break flour and reduction flour. ${\beta}-Glucan$ contents in the bran and shorts from the milled stream were relatively high, and further concentration of ${\beta}-glucan$ could be accomplished by successive sieving of the bran and shorts fractions. Pearled barley and milled stream could be used to prepare barley fractions with ${\beta}-glucan$ concentrations $2.4{\sim}3.1$ times those of the original barley grain. Water solubility of barley ${\beta}-glucan$ from pearled barley and the milled stream was in the range of $40{\sim}81%$.

• International Journal of Korean Welding Society
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• v.3 no.1
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• pp.29-33
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• 2003

The ferritic stainless steels are generally considered to have poor weldability compared with that of the austenitic stainless steels. However the primary advantages of ferritic stainless steels include lower material cost than the more commonly used austenitic stainless steels and a greater resistance to stress corrosion cracking. Thus, the weldability of ferritic stainless steels was investigated in this study. In concerning the weldability, Grain size measurement test, Erichsen test and Varestraint test were involved. full penetration welds were produced by autogeneous direct current straight polarity (DCSP) and pulsed currents gas tungsten arc welding (GIAW) and the effect of pulsed currents welding on the welds was compared to that of DCSP welding. The results showed that pulsed current was effective to refine grain size in the weld metal and the finest grain size was obtained at the frequency of 150Hz. In addition, the ductility of welds was lower than that of base metal. Finally, autogeneous type 444 welds were less susceptible to macro solidification cracks, but more sensitive to micro cracks; SEM/EDS analysis indicated that all the inclusions in the crack showed enrichment of Mn, Si, O and S.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.34.4-34.4
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• 2010

We present the properties of globular cluster systems for 10 early-type galaxies in low density environments obtained using deep images from the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). Using the ACS Virgo Cluster Survey as a counterpart in high-density environments, we investigate the role of environment in determining the properties of their globular cluster systems. We detect a strong colour bimodality of globular cluster systems in half of our galaxy sample. It is found that there is a strong correlation between the colour and richness of globular cluster populations and their host galaxy luminosities: the less bright galaxies possess bluer and fewer globular clusters as also seen in rich cluster environments. However, the mean colour of globular clusters in our field sample are slightly bluer than those in cluster environments at a given galaxy luminosity, and the colour of the red population has a steeper slope with absolute luminosity. By employing the YEPS simple stellar population model, the colour offset corresponds to metallicity difference of $\Delta$[F e/H ] ~ 0.15 - 1.20 or an age difference of $\Delta$age ~ 2 Gyr on average, implying that GCs in field galaxies appear to be either less metal-rich or younger than those in cluster galaxies. Although we have found that galaxy environment has a subtle effect on the formation and metal enrichment of GC systems, host galaxy mass is the primary factor that determines the stellar populations of GCs and the galaxy itself.

• Molecules and Cells
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• v.44 no.10
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• pp.746-757
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• 2021

Plant somatic cells can be reprogrammed into a pluripotent cell mass, called callus, which can be subsequently used for de novo shoot regeneration through a two-step in vitro tissue culture method. MET1-dependent CG methylation has been implicated in plant regeneration in Arabidopsis, because the met1-3 mutant exhibits increased shoot regeneration compared with the wild-type. To understand the role of MET1 in de novo shoot regeneration, we compared the genome-wide DNA methylomes and transcriptomes of wildtype and met1-3 callus and leaf. The CG methylation patterns were largely unchanged during leaf-to-callus transition, suggesting that the altered regeneration phenotype of met1-3 was caused by the constitutively hypomethylated genes, independent of the tissue type. In particular, MET1-dependent CG methylation was observed at the blue light receptor genes, CRYPTOCHROME 1 (CRY1) and CRY2, which reduced their expression. Coexpression network analysis revealed that the CRY1 gene was closely linked to cytokinin signaling genes. Consistently, functional enrichment analysis of differentially expressed genes in met1-3 showed that gene ontology terms related to light and hormone signaling were overrepresented. Overall, our findings indicate that MET1-dependent repression of light and cytokinin signaling influences plant regeneration capacity and shoot identity establishment.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1022-1028
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• 2024

A neutronics study of a supercritical CO₂-cooled fast reactor core for nuclear propulsion has been performed in this work. The thermal power of the reactor core is 30 MWth and a ceramic UO₂ fuel can be used to achieve a 20-year lifetime without refueling. In order to make a compact core with inherent safety features, the drum-type reactivity control system and folding-type shutdown system are adopted. In addition, we suggest a cold shutdown system using gadolinium as a spectral shift absorber (SSA) against flooding. Although there is a penalty of U-235 enrichment for the core embedded with the cold shutdown system, it effectively mitigates the increment of reactivity at the flooding of seawater. In this study, the neutronics analyses have been performed by using the continuous energy Monte Carlo Serpent 2 code with the evaluated nuclear data file ENDF/B-VII.1 Library. The supercritical CO₂-cooled fast reactor core is characterized in view of important safety parameters such as the reactivity worth of reactivity control systems, fuel temperature coefficient (FTC), coolant temperature coefficient (CTC), and coolant temperature-density coefficient (CTDC). We can say that the suggested core has inherent safety features and enough flexibility for load-following operation.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.35.2-35.2
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• 2013

I will present a new approach to constrain galaxy physical parameters from the combined interpretation of stellar and nebular emission in wide ranges of observations. This approach relies on a comprehensive library of synthetic spectra, assembled using state-of-the-art models of star formation and chemical enrichment histories, stellar population synthesis, nebular emission and attenuation by dust. We focus on the constraints set by 5-band photometry and low- and medium-resolution spectroscopy at optical rest wavelengths on a few physical parameters characterizing the stars and interstellar medium. Since these parameters cannot be known a priori for any galaxy sample, we assess the accuracy to which they can be retrieved by simulating 'pseudo-observations' using models with known parameters. We find that the combined analysis of stellar and nebular emission in low-resolution (50A FWHM) galaxy spectra provides valuable constraints on all physical parameters. The approach can be extended to the analysis of any type of observation and during this talk i will present some applications to observed galaxies up to redshift 1.5.

• Mass Spectrometry Letters
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• v.8 no.1
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• pp.8-13
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• 2017

Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (${\mu}M$), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, $94.8{\pm}3.1-98.5{\pm}3.3%$, $4.34{\pm}0.28-4.40{\pm}0.30$, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.347-352
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• 1996

Studies on tile microstructural and compositional changes in sensitized Ni base Alloy 600 by laser surface melting have been carried out using TEM equipped with EDXA. The microstructure of the laser melted zone was mainly consisted of fine cells, and along the cell and grain boundaries, Cr enrichment due to its segregation was observed. Cr carbides having formed along the grain bundaries during the sensitization treatment have been completely dissloved. The cell walls were decorated with dislocations and the very tiny precipitates, found to be Ti(CN) type, were distributed randomly along the cell walls with tangled dislocations around them.

• Bulletin of Food Technology
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• v.15 no.4
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• pp.29-35
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• 2002

To prevent the incidence of type food allergies, removal of food allergens by excluding all foodstuffs containing the allergen(s) or disruption of allergen(s) using proteases has been employed. Though allergen- specific digestion with a protease worked well in the preparation of low allergenic goods, it is often difficult to destroy allergenicity without adversely affecting the nutritive value, taste and rheological properties of foods. In the present study, we represented that herbs component contained both allergy- enhancing and inhibiting factors, in addition to llergens. We also reported that herbal component such as epigallocatechingallate (EGCG) and epicatechingallate (ECG) is possible to be allergy- inhibiting factors, but the exact mechanism by which they alleviate allergic response is left to be clarifying. Document of allergy enhancing factors and enrichment of allergy inhibiting factors may provide a new approach to diminish allergenicity of various foodstufffs. Clarification of the allergic reaction modifying mechanism of food components and optimization of the intake of allergy modifying factor are necessary for decrement of allergenicity of conventional food and prevention of incidents of allergic response

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.29.1-29.1
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• 2010

Recent observations reveal that some early-type galaxies show a color-magnitude relation of blue globular clusters (GCs) in the color-magnitude diagrams, which is referred to as 'blue tilt'. This phenomenon is interpreted as a mass-metallicity relation -- metallicities of blue GCs increase with increasing mass, and thus provides a crucial clue to the chemical enrichment processes of GCs as a function of their mass. However, some galaxies show 'non-tilt' or even 'reverse blue tilt' on the blue GC sequence, and thus the origin of blue tilt still remains a puzzle. In this study, we put forward the theoretical explanation for the phenomenon and discuss its implications towards galaxy formation scenarios.