• Journal of the Korean Society for Heat Treatment
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• v.21 no.6
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• pp.287-292
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• 2008

Dissolution behavior of complex carbonitrides in a Nb-Ti-V microalloyed steel was quantitatively examined by electrical resistivity, transmission electron microscopy (TEM), and optical microscopy. The electrical resistivity increased with solution treatment temperature up to $1250^{\circ}C$ for a holding time of 15 min. But, an increasing rate of electrical resistivity with temperature was obviously decreased above $1150^{\circ}C$. As the solution treatment temperature increases, irregular shaped Nb-rich carbonitrides disappear and cuboidal Ti-rich carbonitrides are observed. Abnormal grain growth occurs above $1250^{\circ}C$ for a holding time of 15 min. The optimal solution treatment temperature of a Nb-Ti-V microalloyed steel was determined as $1200^{\circ}C$ for a holding time of 15 min.

• Acta Via Serica
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• v.7 no.2
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• pp.133-152
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• 2022

Both in popular perception and specialized literature, the Achaemenid Empire, for over two centuries the most important player from the Aegean to the Indus, is rarely evoked in correlation with the complex of socio-cultural dynamics which shaped the spaces of what has become known as the Silk Road(s). Building on the case study of the Pazyryk carpet on the one hand (King 2021, 353-361, Linduff and Rubinson 2021, 88-97), and of the spread of an artistic motive such as the quatrefoil on the other (Kim 2021), this paper explores the rich and complex nature of the commercial networks that flourished across Central Asia under the aegis of Achaemenid Great Kings. Both archaeological and literary evidence shall be discussed (especially the Aramaic Documents from Ancient Bactria: Naveh and Shaked 2012, and now King 2021, 315-320). If taken together and read against the grain, such material is significant for the following reasons. First, it suggests the existence - and the scale - of commercial activities directly fostered or indirectly promoted by the imperial administration in Central Asia, an area of crucial importance within the Achaemenid domains, but for which our evidence is rather scanty and difficult to assess. Second, it shows how the Achaemenid "Imperial Paradigm" (Henkelman 2017) affected the social and economic landscape of Central Asia even after the demise of the Empire itself, thus considerably shaping the world of the Silk Road(s) a century before the Ancient Sogdian Letters (de la Vaissière 2005, 43-70) or Zhāng Quiān's famous report.

• Korean Journal of Materials Research
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• v.32 no.2
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• pp.72-79
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• 2022

A cold roll-bonding process using AA1050, AA5052 and AA6061 alloy sheets is performed without lubrication. The roll-bonded specimen is a multi-layer complex aluminum alloy sheet in which the AA1050, AA5052 and AA6061 sheets are alternately stacked. The microstructural evolution with the increase of annealing temperature for the roll-bonded aluminum sheet is investigated in detail. The roll-bonded aluminum sheet shows a typical deformation structure in which the grains are elongated in the rolling direction over all regions. However, microstructural evolution of the annealed specimen is different depending on the type of material, resulting in a heterogeneous microstructure in the thickness direction of the layered aluminum sheet. Complete recrystallization occurs at 250 ℃ in the AA5052 region, which is lower by 100K than that of the AA1050 region. Variation of the misorientation angle distribution and texture development with increase of annealing temperature also differ depending on the type of material. Differences of microstructural evolution between aluminum alloys with increase of annealing temperature can be mainly explained in terms of amounts of impurities and initial grain size.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.226-231
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• 1994

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.54-63
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• 2002

Post-harvest technology for rice was focused on in-bin drying system, which consists of about 100, 000 facilities in 1980s. The modernized Rice Processing Complex (RPC) and Drying Storage Center (DSC) became popular for rice dry, storage, process and distribution from 1990s. However, the percentage of artificial drying for rice is 48% (2001) and the ability of bulk storage is about 15%. Therefore it is necessary to build enough drying and bulk storage facilities. The definition of high quality rice is to satisfy both good appearance and good taste. The index for good taste in rice is a below 7% of protein, 17-20% of amylose, 15.5-16.5% of moisture contents and high concentration of Mg and K. To obtain a high quality rice, it is absolutely needed to integrate high technologies including breeding program, cropping methods, harvesting time, drying, storing and processing methodologies. Generally, consumers prefer to rice retaining below b value of 5 in colorimetry, and the whiteness, the hardness and the moisture contents of rice are in order of consumer preference in rice quality. By selection of rice cultivars according to acceptable quality, the periods between harvesting time and drying reduced up to about 20 days. Therefore it is necessary to develop a low temperature grain drying system in order to (1) increase the rate of artificial rice drying up to 85%, (2) keep the drying temperature of below 45C, (3) maintain high quality in rice and (4) save energy consumption. Bulk storage facilities with low temperature storage system (7-15C) for rice using grain cooler should be built to reduce labor for handling and transportation and to keep a quality of rice. In the cooled rice, there is no loss of grain quality due to respiration, insect and microorganism, which results in high quality rice containing 16% of moisture contents all year round. In addition, introducing a low temperature milling system reduced the percentage of broken rice to 2% and increased the percentage of head rice to 3% because of proper hardness of grain. It has been noted that the broken rice and cracking reduced significantly by using low pressure milling and wet milling. Our mission for improving rice market competitiveness goes to (1) produce environment friendly, functional rice cultivars, (2) establish a grade standard of rice quality, (3) breed a new cultivar for consumer oriented and (4) extend the period of storage and shelf life of rice during postharvest.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.37.3-38
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• 2021

One of the key questions on star formation is how the organic molecules are synthesized and delivered to the planets and comets since they are the building blocks of prebiotic molecules such as amino acid, which is thought to contribute to bringing life on Earth. Recent astrochemical models and experiments have explained that complex organic molecules (COMs; molecules composed of six or more atoms) are produced on the dust grain mantles in cold and dense gas in prestellar cores. However, the chemical networks and the roles of physical conditions on chemistry are not still understood well. To address this question, hot (> 100 K) cores in high mass young stellar objects (M > 8 Msun) are great laboratories due to their strong emissions and larger samples than those of low-mass counterparts. In addition, CH₃OH masers, which have been mostly found in high mass star forming regions, can provide constraints due to their very unique emerging mechanisms. We investigate twelve high mass star forming regions in ALMA band 6 observation. They are associated with 44/95 GHz Class I and 6.7 GHz Class II CH3OH masers, implying that the active accretion processes are ongoing. For these previously unresolved regions, 66 continuum peaks are detected. Among them, we found 28 cores emitting COMs and specified 10 cores associated with 6.7 GHz Class II CH3OH masers. The chemical diversity of COMs is found in cores in terms of richness and complexity; we identified up to 19 COMs including oxygen- and nitrogen-bearing molecules and their isotopologues in a core. Oxygen-bearing molecules appear to be abundant and more complex than nitrogen-bearing species. On the other hand, the COMs detection rate steeply grows with the gas column density, which can be attributed to the effective COMs formation in dense cores.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.1007-1013
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• 2010

This study was conducted to evaluate the effects of dietary complex enzyme (${\beta}$-mannanase 800 IU/kg and xylanase 700 IU/kg) in a diet containing corn distiller's dried grain with soluble (DDGS) on meat quality and pork fatty acid composition. Ninety-six pigs ([(Landrace${\times}$Yorkshire)${\times}$Duroc], with an average body weight of 68.77 kg were used in the 8 wk growth assay. Dietary treatments included 1) corn-soybean meal diet, 2) corn-soybean meal diet + 0.05% enzyme complex, 3) cornsoybean meal diet with DDGS and 4) corn-soybean meal diet with DDGS + 0.05% enzyme complex. The pigs were allotted randomly into pens (n=4 per pen) with six replicate pens per treatment by a completely randomized design. Pigs were slaughtered at the end of the experiment and the loin muscle was obtained for meat quality. Meat pH (p<0.01), firmness (p<0.01) and redness (p<0.05) were higher in DDGS-supplemented diet than in the corn-soy bean meal diet. However, color, marbling, lightness, yellowness, thiobarbituric acid reactive substances, water holing capacity, driploss, cooking loss and loin muscle area were not significantly different among the diets. The pigs fed the DGGS-supplemented diet had higher total unsaturated fatty acids (UFA) and total UFA/saturated fatty acid (SFA) ratio of loin and backfat. The results indicate that a diet containing DDGS can influence pH, firmness, redness and total UFA concentration and total UFA/SFA ratio of meat and backfat, but that enzyme addition has no affect on meat quality.

• Advances in materials Research
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• v.2 no.1
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• pp.1-13
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• 2013

Lead-free compound $(Na_{0.5}Bi_{0.5})(Zr_{0.75}Ti_{0.25})O_3$ was prepared using conventional ceramic technique at $1070^{\circ}C$/4h in air atmosphere. X-ray diffraction analysis showed the formation of single-phase orthorhombic structure. Permittivity data showed low temperature coefficient of capacitance ($T_{CC}{\approx}5%$) up to $100^{\circ}C$. Complex impedance studies indicated the presence of grain boundary effect, non-Debye type dielectric relaxation and evidences of a negative temperature coefficient of resistance. The ac conductivity data were used to evaluate the density of states at Fermi level and apparent activation energy of the compound.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.107-110
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• 2002

The optical memory devices of BST thin films to composite $(Ba_{0.7}\;Sr_{0.3})TiO_{3}$ using sol-gel method were fabricated by changing of the depositing layer number on $Pt/Ti/SiO_{2}/Si$ substrate. The structural properties of optical memory devices to be ferroelectric was investigated by fractal analysis and 3-dimension image processing. The thickness of BST thin films at each coating numbers 3, 4 and 5 times was $2500[\AA]$, $3500[\AA]$ and $3800[\AA]$. BST thin films exhibited the most pronounced grain growth. The surface morphology image was roughness with coating numbers. The thin films increasing with coating numbers shows a more textured and complex configuration.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.1
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• pp.119-126
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• 2006

The finishing process of die requires the processing technique of a height efficiency and precision. Because the precision of die gives the quality of goods the influence directly. The hydro-static polishing device employs the hydro-static axis and is able to polish the structure of complex picture under the constant pressure and is got constant surface roughness at all polished plane. Therefore, In order to polish precision sculptured surface, it was used the hydro-static polishing device. Polishing device's polishing characteristic is estimated by polishing conditions which are size of abrasive, material of tools. And, because the surface quality of workpiece depends on polishing pattern which relates to motion of abrasive grain. The polishing characteristic according to polishing pattern was evaluated.