• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1462-1467
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• 2007

This study investigated the effect of chemical treatments on tannins (condensed and hydrolysable) and on the trypsin inhibitor (TI) activity in salseed meal. Triplicate samples of ground salseed meal (1 kg) were mixed with 820 ml of either distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), 0.67 M sodium bicarbonate (pH 8.2) or 2% polyvinyl-pyrrolidone (PVP) solution. The material was placed in airtight plastic containers and incubated at $37^{\circ}C$ for 0, 3, 6, 12, 24, 48 and 72 h. Samples of untreated salseed meal which had not been subjected to soaking or incubation were run through the analysis to serve as control. Addition of water, acetic acid, sodium bicarbonate and PVP solutions to salseed meal and subsequent anaerobic incubation at $37^{\circ}C$ significantly reduced chemically detectable tannins. At each incubation time, alkali solution was more effective than its counterparts. The effect of acidic solution on hydrolysable tannin was least among the treatments. All the treatments reduced TI activity of salseed meal. The reduction in TI activity by these treatments was similar and ranged between 80-84%. Treatment time effected a decrease in the contents of antinutritional substances. However, the effect of the treatment with the reagents, even for zero incubation time, was quite pronounced. It may be concluded from the present results that the treatment of salseed meal with sodium bicarbonate (0.67 M) is more effective in reducing hydrolysable and condensed tannin contents than PVP, water and acid solutions. Treatment with sodium bicarbonate solution is more economical and easier to handle than acid and PVP treatments. Incubation of the treated material for 12 h is reasonably effective, economical and safe from any mould growth.

• Journal of Science of Art and Design
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• v.3
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• pp.87-144
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• 2001

This study looks into historical genealogy of autonomy in art criticism on modernism and presents the view of the judgment and correction about that. A matter of autonomy in art appeared in the attempt to totally reconsider and upset the theory of 'Mimesis' or 'Representation' which was the basis of traditional aesthetic theory. In the traditional theory of representation, they assumed primary image exists first and then tried to obtain visual similarity to it through art works. However, in the theory of autonomy in modernism, they maintained the reduction to pure form' or medium', regarding what art works represents and how similar to primary image are not the true essence of art. In the early 20th century, C. Bell laid the foundation stone of the theory of Formalism', providing that a matter of autonomy is significant form', which is the combination of lines and colors Aesthetic autonomy theory came to a climax by C. Greenberg, who systemized art criticism on modernism in the middle 20th century. According to his theory, the pursuit of the essence of form resulted in the specificity of medium' and flatness. They thought that the autonomy of art would be achieved by eliminating outward social factors from art works. This theory ended by Minimalism preventing the instructive function of art work and only emphasizing its material property. Since the middle 20th century, the autonomy theory was confronted with the limit and intense attack because it resulted in this fixed canon and materialism, so they began laying emphasis on those extrinsic factors around art works such as human life, society, history, and so on. This study focuses on arguing and complementing the limit of autonomy such as the adhesive and fixed canon, and then defining the more dynamic area of it. For this, first, I introduced the view of T. J. Clark and T. Crow who criticized the aesthetic autonomy theory. They denied the transcendental structure of form, and found form only in the association with substantial life and society. And they insisted the dynamism of form by emphasizing form as a result of negation insisted by avant-garde. Second, I researched the view of A. C, Danto and M. Fried, who complemented the traditional autonomy theory. They made autonomy emerge from the fixation of form like flatness through connecting essentialism with historical view. In conclusion, I insist that autonomic position of art make it possible to connect or mediate between material form and human or social elements. Therefore, autonomy should not be reduced to the axis of form or that of society but make interaction between two heterogeneous axes.

• Journal of Korea Water Resources Association
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• v.45 no.5
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• pp.445-454
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• 2012

The present study aims to investigate the long-term channel morphological changes derived from channelization, embankment and levee construction works in unregulated fluvial channel of the Jiseock River. Analyses of aerial photographs taken past (Year 1966) and recent (Year 2002) showed the temporally remarkable changes in channel planform such as channel shape, bar migration, vegetation encroachment in bar. During the period, the natural single threading changed into braided types together with decreasing sinuosity by 9.2%, increasing vegetation occupied bar ranged 97% of total bars area. Because such channel morphological changes are closely similar to those in dam downstream channels, we assume that both/either flow regime alteration and/or sediment transport discontinuity may be critical for the fixed channel and spread of vegetated bars even in unregulated river without dam reservoir upstream. We found more reduced frequency and magnitude of flooding water level comparing with past, but no significant alteration of inter annual water level variation. Bed material has been coarsened by 4~5 times and the riverbed has been degraded in overall channel but aggraded locally in conjunction reach of tributaries. The results indicates that reduced sediment dynamics in fluvial channel which derived by bed material coarsening, river bed degradation and unbalanced sediment transport capacity between tributary and mainstem can be a causal factor to trigger channel morphological changes even in unregulated rivers.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.221-243
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• 1997

The objective of this study was to characterize the mechanical properties of $Y_{2}O_{3}$-containing glass infiltrated ceramic core material, which was made by pressureless powder packing method. A pure alumina powder with a grain size of about $4{\mu}m$ was packed without pressure is silicon mold to form a bar shaped sample, and applied PVA solution as a binder. Samples were sinterd at $1350^{\circ}C$ for 1 hour. After cooling, $Y_{2}O_{3}$-containing glass($SiO_{2},\;Y_{2}O_{3},\;B_{2}O_{3},\;Al_{2}O_{3}$, ect) was infiltrated to the sinterd samples at $1300^{\circ}C$ for 2 hours and cooled. Six different proportions $Y_{2}O_{3}$ of were used to know the effect of the mismatch of the thermal expansion coefficient between alumina powder and glass. The samples were ground to $3{\times}3{\times}30$ mm size and polished with $1{\mu}m$ diamond paste. Flexural strength, fracture toughness, hardness and other physical properties were obtained, and the fractured surface was examined with SEM and EPMA. Ten samples of each group were tested and compared with In-Ceram(tm) core materials of same size made in dental laboratory. The results were as follows : 1. The flexural strengths of group 1 and 3 were significantly not different with that of In-Ceram, but other experimental groups were lower than In-Ceram. 2. The shrinkage rate of samples was 0.42% after first firing, and 0.45% after glass infiltration. Total shrinkage rate was 0.87%. 3. After first firing, porosity rate of experimental groups was 50%, compared with 22.25% of In-Ceram. After glass infiltration, porosity rate of experimental groups was 2%, and 1% in In-Ceram. 4. There was no statistical difference in hardness between two materials tested, but in fracture toughness, group 2 and 3 were higher than In-Ceram. 5. The thermal expansion coefficients of experimental groups were varied to $4.51-5.35{\times}10^{-6}/^{\circ}C$ according to glass composition, also the flexural strengths of samples were varied. 6. In a view of SEM, many microparticles about $0.5{\mu}m$ diameter and $4{\mu}m$ diameter were observed in In-Ceram. But in experimental group, the size of most particles was about $4{\mu}m$, and a little microparticles was observed. The results obtained in this study showed that the mismatch of the thermal expansion coefficients between alumina powder and infiltrated glass affect the flexural strength of alumin/glass composite. The $Y_{2}O_{3}$-containing glass infiltrated ceramic core made by powder packing method will takes less time and cost with sufficient flexural strength similar to all ceramic crown made with slip casting technique.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.47-52
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• 2010

This study was carried out to investigate the availability of covering material used for raising seedlings in the rice nursery bed. The pre-germinated seeds of a rice cultivar 'Chilbo' were sown into seedling tray ($60{\times}30{\times}2.5cm$) on 20th April and 3rd May 2010. Polypropylene spunbonded fabric (PSF) and lagging were used for covering materials in rice nursery bed. The growth characteristics of seedlings were evaluated at 8, 15 and 25 days after sowing (DAS) in the nursery beds covered with PSF and lagging, respectively. The plant height of 8-day old seedlings grown in lagging nursery bed was longer by 2cm than those in PSF nursery bed when the seeds were sown on 20th April, but seedling quality grown in lagging nursery bed was poor compared with that in PSF nursery bed. The growth characteristics of 15-day old seedlings were similar to that of 8-day old seedlings. The plant height of 8, 15 and 25-day old seedlings grown in lagging nursery was longer than those in PSF nursery when the seeds were sown on 3rd May. The seedling quality grown in PSF nursery was better than that in lagging nursery. The seedlings grown in PSF nursery have more leaves and better seedling quality compared with that of lagging nursery. The seedling quality was remarkably decreased with the increase of nursery period in lagging bed but seedlings quality were recovered at 5 days after hardening treatment by removing the lagging.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.392-397
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• 2012

In the $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1})O_3$ (LCCC), which has been using as interconnector materials in SOFC, Al ions were substituted for Co because ionic radius of Al is similar to that of Co. Because of the almost identical ionic radius of Al and Co, the substitution was not thought to be affect the tolerance factor of LCCC, and the densification behavior, high temperature electrical conductivity and thermal expansion coefficient were examined as a function of Al concentration. In the cases of the x= 0 and x= 0.02 in $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1-x}Al_x)O_3$ (x= 0~0.1), the samples showed the relative densities above ${\geq}95%$ when those were sintered at ${\geq}1,350^{\circ}C$. In the case of the $x{\geq}0.06$ the sintered density deteriorated greatly at lower sintering temperatures. High temperature electrical conductivity of the samples decreased as the content of Al increased. Since the valence state of Al ion is unchangeable, while Cr or Co ions contribute to the electrical conduction by changing those valence states, Al substitution resulted in the decreased electrical conductivity. Al doping of LCCC was an effective way of decreasing the thermal expansion coefficient (TEC).

• Economic and Environmental Geology
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• v.53 no.2
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• pp.197-212
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• 2020

This study was carried out material characteristics and firing conditions for some potteries in early and middle Neolithic period at the Munamri sites, where the first farmland remails were found in Korea. It is divided into six kinds of surface patterns for potteries such as the raised, bamboo tube and red painted (patternless) from the early Neolithic period (BC 4000 to 6000), and the patterns of horizontal herringbone, short slanted lined or lattice and incised thick line in the middle Neolithic period (BC 3000 to 4000), respectively. Based on the color measures, redness and yellowness of potteries were relatively high as condition of oxidation firings, were also observed black cores on the cross section of potteries. The firing temperature is divided into two groups having under 800℃ and 800to 900℃, the difference in patterns of the potteries are not confirmed. As a microtextures, the bamboo tube pattern potteries show the sericitization biotite, the quartz have developed a suture line textures, and altered alkali feldspars are occurred. X-ray diffraction analysis shows that the main minerals contained in potteries are chlorite and amphibole besides quartz, alkali feldspar and biotite. Considering the geology around the Munamri area is the biotite amphibole granite and soil layers within 10km radius are used as the raw materials for the potteries. The raw materials are presumed that the sources from the metamorphic rocks along the water systems through the mountains around the sites on the basis of well developed suture line textured quartz in potteries. Results on normalized geochemical compositions, the potteries by surface patterns are very similar to sources, and it is judged that was made by using the surrounding soils despite the long time difference from the early to middle in the Neolithic period.

• Journal of Conservation Science
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• v.36 no.3
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• pp.152-161
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• 2020

The purpose of this study was to compare the chemical properties of white soil and refined clay sediment, which are produced early in the refining process. The characteristics of the white wares made at the kiln site in Goseong-ri, Chuncheon were also examined. Three groups of materials were examined: white wares excavated from the white wares kiln, raw material from white soil collected from the surface, and a refined clay sediment group. There were also three analysis methods, which were a main components analysis, a trace components analysis, and a mineral analysis. The main components analysis found that the white wares clay was in the RO₂4.04~4.28 and the RO + R₂O 0.30~0.31 mole areas, which were similar to the results for the refined clay sediment. However, the refining process used to produce better quality white wares meant that the large differences in the early white soil raw material appeared in the refined sediment. The mineral phase analysis showed that the crystals detected in the early white soil raw materials and refined clay sediment were almost identical. However, quartz and mullite mineral phases, which can occur above a certain temperature, were detected in the excavated white wares clay. Rare earth elements that were not affected by the pottery making process and the weathering of clay materials were found to have the same origin in all three groups.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.200-204
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• 1998

Physical and chemical properties of artificial soil produced by firing process were analyzed and compared with normal dry field soil and soil quality standards. Material used for production was water and wastewater treatment sludge, chabizite, and lime. The mixed material was thermally treated in the firing kiln at about $300^{\circ}C$ and $1,000^{\circ}C$, respectively, as per designed process. General properties of the artificial soil were classified as sand by unified soil classification method and similar to the dry-field soil, and even soil conditioning effect were expected when it is mixed properly with normal soil. The artificial soil is high in pH and permeability compared to the dry-field soil. Heavy metal concentrations of the artificial soil met the soil quality standards for the farmland. Overall, the artificial soil was thought to be an appropriate soil which can be returned safely to the nature without significant adverse effect. The cost for the artificial soil production process needs to be lowered for practical application as a sludge treatment, therefore, commercializing of the artificial soil is under review.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.69-74
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• 2018

With the increasing development of industrial society and the availability of high quality electrical energy, the simplification of operation and maintenance procedures is required, in order to ensure the reliability and safety of electrical systems. In this paper, the dielectric breakdown characteristics of $N_2-O_2$ mixed gas solid insulation, which is used as an alternative to SF6 in various electric power facilities, are verified. When the gas mixture has a composition ratio similar to that of the atmosphere, the dielectric breakdown characteristics are relatively stabilized. It was confirmed that the breakdown voltage of the gas in the electrode near an equal electric field increased with increasing pressure according to Paschen's rule. The breakdown voltage of the surface increased linearly with increasing pressure, and the difference was caused by the mixing ratio of $O_2$ gas. This change in the surface insulation breakdown voltage was caused by the influence of the electrically negative $O_2$ gas and the intermolecular collision distance. In this study, the influence of the intermolecular impact distance was larger (than that in the absence of the electrically negative $O_2$ gas). The breakdown voltage relation applicable to Teflon according to the surface insulation characteristics was calculated. The characteristics of the surface insulation properties of Teflon, which is used as a solid insulation material, were derived as a function of pressure. It is thought that these results can be used as the basic data for the insulation design of electric power facilities.