• Resources Recycling
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• v.19 no.4
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• pp.41-50
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• 2010

A fundamental study was carried out to develop a process for recycling tungsten and cobalt from WC-Co hardmetal sludge generated in the manufacturing process of hardmetal tools. The complete extraction of cobalt and simultaneous formation of tungstic was achieved by treating the sludge using aqua regia. The effect of aqua regia concentration, reaction temperature and time, pulp density on cobalt leaching and tungstic acid formation was investigated. The complete leaching of cobalt was attained at the optimum conditions: 100 vol.% aqua regia concentration, $100^{\circ}C$ temperature, 60 min. reaction time and 400 g/L pulp density. A complete conversion of tungsten carbide of the sludge to tungstic acid was however, obtained at the pulp densities lower than 150 g/L under the above condition. The progress of reaction during the aqua regia treatment of the sludge was monitored through the XRD phase identification of the residue. The metallic impurities in the tungstic acid so produced could be further removed as insoluble residues by dissolving the tungsten values in ammonia solution. The ammonium paratungstate($(NH_4)_{10}{\cdot}H_2W_{12}O_{42}{\cdot}4H_2O$) of 99.85% purity was prepared from the ammonium polytungstate solution by the evaporation crystallization method.

• Food Science and Preservation
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• v.17 no.4
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• pp.526-532
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• 2010

Changes in the nutritional components of Daebong-gam (astringent persimmon) fruit were studied during ripening. The pH rose during ripening and total acidity level fell, from pH 5.36 to pH 5.96 and 0.13% to 0.06%, respectively. Total soluble content did not significantly change. Lightness, redness, and yellowness values, as well as ascorbic acid content, decreased during ripening. The levels of moisture, crude protein, and crude fat also decreased, but nitrogen-free content and crude ash level increased. Daebong-gam was rich in K (96.31~239.47 mg/100 g), P (49.10~55.93 mg/100 g), and Na (15.96~18.13 mg/100 g). Fructose and glucose levels were initially high and increased further during ripening. The glucose content was 4.82% in Daebong-gam, 6.73% in Ban-si, and 7.10% Yeon-Si, respectively. Proline, glutamic acid, and aspartic acid were present at high levels in Daebong-gam. The most common fatty acids were palmitic acid and linolenic acid. Succinic acid was the principal organic acid present.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.331-339
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• 2020

The purpose of this study is to investigate the correlation and agreement between heart rates of Polar heart rate monitor and a smartwatch in order to confirm the accuracy of heart rate measured by the smartwatch. Heart rates of fifty college students were measured for a total of 12 minutes under four conditions: rest, walk, Zumba, and cycle. As a result of correlation and agreement analysis between heart rates of the two devices, correlation coefficient (r) was 0.995 at rest, 0.991 at walk, 0.923 at Zumba, 0.932 at cycle, and Bland-Altman ratio (BA ratio) was 0.02 at rest, 0.03 at walk, 0.06 at Zumba, 0.04 at cycle. Heart rate from smartwatch showed high correlation and agreement with heart rate from Polar in all conditions, representing that smartwatch can be considered an reliable apparatus to measure hear rate.

• Research in Plant Disease
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• v.20 no.4
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• pp.275-282
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• 2014

The occurrence of post-harvest diseases and their pathogens in 'Campbell Early' which is the most produced grape in Korea was investigated. The 'Campbell Early' grapes produced in 3 main grape-producing areas were stored in a cold room ($0-4^{\circ}C$) for 2 weeks then at room temperature for 4 weeks prior to investigation. The major post-harvest diseases occurred were gray mold, blue mold, ripe rot, new decay 1, and new decay 2. Pathogens isolated from the symptoms were identified as Botrytis cinerea for gray mold, Penicillium sclerotiorum for blue mold and Collectrichum acutatum for ripe rot. Pathogens for new decay 1 and new decay 2 were not identified yet. Incidences of new decay 1 and new decay 2 were much higher than the other 3 decays in all grapes produced from 3 areas. Gray mold and blue mold occurred at much lower frequencies than these two decays, and ripe rot occurred least.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.432-439
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• 2004

Increase in water vapor barrier properties of sodium alginate films was studied by preparing composite films with fatty acids, i.e., lauric, palmitic, stearic, and oleic acids, and by treatment with 3% $CaCl_{2}$ solution for 3 min. Film thickness, surface color, microstructure, tensile strength (TS), elongation at break (E), water vapor permeability (WVP), water solubility (WS), and sorption isotherm of films were investigated. Microstructure of films observed with SEM was changed by fatty acid and $CaCl_{2}$ treatments. TS decreased 25-70% depending on fatty acid used, and increased 1.5- to 2-fold by $CaCl_{2}$ treatment. E decreased by both fatty acid and $CaCl_{2}$ treatments. Except oleic acid, WVP decreased significantly (p<0.05) by forming composite films with fatty acids, particularly with stearic acid, WVP decreased more than two-fold. WS also decreased by fatty acid and $CaCl_{2}$ treatments. In stearic acid, WS decreased about 30-fold by combined treatment of fatty acid and $CaCl_{2}$. Sorption isotherm showed typical biphasic pattern with deliquescent point of 0.75. Results of isotherms and BET monolayer moisture content indicated hydrophilicity of film decreased by $CaCl_{2}$ treatment.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.142-149
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• 2015

Bioaerosols are comprised of particles 0.02-100 μm in size that originate in natural and artificial environments, and as a result of human activities. They consist of microorganisms including viruses, bacteria, fungi, and protozoa; fungal spores; microbial toxins; pollen; plant or animal material; expectorated liquid from humans; and glucans (peptidoglycan and β-glucan). Bioaerosols can cause respiratory and other diseases in humans and animals. In this study, bioaerosol samples acquired from agricultural sources, livestock, a sewage treatment plant, a beach, and a pristine area were analyzed to identify and phylogenetically characterize culturable microorganisms. The isolated bacteria exhibited regional differences, with different species dominating. However, Bacillus cereus was isolated in all samples, with a total of 31 strains isolated from all areas, and Acinetobacter baumannii was isolated from an indoor poultry farm. In addition, bacteria determined to be of novel genus or species of the genera Domibacillus, Chryceobacterium, Nocardioides and family Comamonadaceae were isolated from the agricultural, livestock and beach environments.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.443-450
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• 2009

The purpose of this study is to observe activation of limbic system during performing visuospatial tasks by 21% and 30% oxygen administration. Eight right handed male college students were selected as the subjects for this study. A visuospatial task was presented while brain images were scanned by a 3T fMRI system. The experiment consisted of two runs: one was a visuospatial task under normal air(21% oxygen) condition and the other under hyperoxic air(30% oxygen) condition. The neural activations were observed at the limbic system which is seperated 8 regions such as cingulate gyrus, thalamus, limbic lobe, hypothalamus, hippocampus, parahippocampa gyrus, amygdala, and mammiilary body. By two oxygen levels, activation areas of limbic system are almost identical. Increased neural activations were observed in the cingulate gyrus and thalamus with 30% oxygen administration compared to 21% oxygen. During 30% oxygen administration, improvement of visuospatial task performance has a relation to increase of neural activation of subcortical structures such as thalamus and cingulate gyrus as well as cerebral cortex.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.501-510
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• 2009

This study is to establish GUI (graphic user interface) in mobile touch phone for grooming user by using two dimensional emotion model determined by multi-dimensional scale method. The processes conducted in the research were as the followings: First of all, visceral, behavioral, and reflective factors of emotion (Norman, 2002) was defined from investigating the life styles of the Grooming users. Secondly, factor analysis was performed to extract the representative emotional words. In the third step, they were mapped into the two-dimensional emotion model through multi-dimensional scaling. Finally, the mapped emotional words were tried to be related to GUI factors of touch phones and normalizing their relation degree between 0 and 1. This study determined GUI factors significantly related to representative emotions described as special, self-centered, sophisticated, free, passionate, neat for application to mobile touch phone. This study determined the major emotion factors that should be considered the most important while designing the GUI factors.

• Clinical and Experimental Pediatrics
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• v.52 no.9
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• pp.1053-1058
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• 2009

Cytomegalovirus (CMV) is one of the most commonly encountered viral pathogens in newborn infants and is found in 0.3-2.4% of all live births. It has been demonstrated that 40-96% of seropositive mothers shed the virus via their breast milk. Breast milk containing CMV can cause almost one-third of CMV infections occurring in infants. A case of postnatal CMV infection in an extremely premature infant (gestational age $24^{+5}$ weeks, birth weight 750 g) transmitted via breast milk is presented. For neonatal intensive care unit (NICU) management of severe thrombocytopenia, anemia, and sepsis syndrome, the infant received repeated transfusions of platelets; intravenous (IV) immunoglobulins; and gamma- irradiated, filtrated packed red cells and was fed her mother's breast milk since the second week of life. CMV infection was diagnosed with positive CMV immunoglobulin M (IgM) and positive urine CMV culture at the second month of life. Considering the negative CMV IgM and urine CMV culture at birth, postnatally-acquired CMV infection was suspected and confirmed with completely identical nucleotide sequence alignments of the infantile blood isolate and the maternal breast milk isolate. To our knowledge, this is the first case of proven postnatal CMV infection transmitted via breast milk in an extremely premature infant in Korea.

• Journal of Conservation Science
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• v.35 no.6
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• pp.573-587
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• 2019

In this study, reproducing specimens were made from mixing domestically produced magnetite, clay and non-plastic raw materials to reproduce the pigments used in the manufacture of traditional cheolhwa buncheong stoneware. In order to reveal the color fomation of glaze, 30 specimens with good color development were analyzed scientifically. Magnetite, which is the main raw material of the pigment, is a pigment capable of creating a dark black color in a reducing environment at 1,200℃. However, it reacts with the additionally added lime component and discolors to greenish yellow color in oxidizing environment at 1,230℃. Hematite is not significantly affected by the firing temperature and environment, but develops a dark black color when mixed with clay with iron content of more than 10%. The fluidity of the pigment is determined by R₂O₃/RO₂ value, which also affects the color development. In the microtexture observation, the color formation of the glaze layer and the iron oxide crystals identified some differences depending on the particle size of the pigment and the firing environment. Reproduced specimens made of magnetite are present in the form of aggregates of iron oxide in the interface between glaze layer and slip layer in the oxidizing environment at 1,200℃. However, in the reducing environment, aggregates of iron oxides do not exist in the reproduced specimens, and they are homogeneously distributed in the glaze layer and formed a dark black color. In contrast, hematite-based specimens form dendritic structures in the glaze layer in an oxidizing environment and develop black.