• Journal of the Korean Ceramic Society
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• v.44 no.8
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• pp.437-444
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• 2007

The broth solution was prepared by the mixing of an uranyl nitrate, THFA, PVA, and water. The uranium concentration of the broth solution was $0.5{\sim}0.8$ mole-U/L and the viscosity of it was $30{\sim}80cSt$. The droplets of this broth solution were farmed in air and ammonia by the vibrating nozzle with the frequency of 100 Hz at the amplitude of $100{\sim}130V$. The diameter of the droplet was about $1900{\mu}m$ from using the nozzle diameter of 1 mm. The diameter of the aged gel was about $1400{\mu}m$ after aging in ammonia solution at $60{\sim}80^{\circ}C$, and the dried gel with the diameter of about $900{\mu}m$ was obtained after drying at room temperature or partially vacuum condition. The diameter of the calcined $UO_3$ microsphere after calcination at $600^{\circ}C$ appeared about $800{\mu}m$ in air atmosphere. Although the droplets of the same sizes were formed, the calcined microspheres of different sizes were manufactured in the case of the broth solutions of the different uranium concentration. The droplets of the desired diameters were obtained by the change of the nozzle diameters and the broth flow rates.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.458-467
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• 2016

Salt is the most important substance in physiological activities of the human body concerning transport of the ingested nutrients into the blood. Thus, the most ideal salt must not contain any harmful ingredients such as cadmium, mercury, lead, and arsenic. However, it is legal to include trace amounts of the hazardous ingredients in salt owing to a technical limitation, because salt is generally obtained from seawater. This paper reported an experimental result about a new method of manufacturing high-quality table salts without hazardous ingredients by using "$15^{\circ}C$ low-temperature vacuum drying technology," applied to the sequential extraction phenomenon of seawater with increasing the concentration. The world's best table salt can be produced if the present results are applied and extended to the traditional solar salt industry.

• Journal of Conservation Science
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• v.12 no.1 s.15
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• pp.71-82
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• 2003

The paper relics excavated from the 4th excavation of the historical spot No.259 Seonwon temple area were analyzed and conserved. Because these works remained folded, the most important conservation treatment was a separation. This process depended on the state of the works: dry state works were separated using Gore-Tex chamber and the filtrated water, wet state works were separated through vacuum freeze drying method. Analyses of the paper relics performed were examination on the paper to find its distinction, binocular microscope and SEM on fiber, and XRF on character ingredient. This study presumed the times though $C^{14}$ dating of these works. The works were able to be classified through analysis and conservation treatment. This separation made lost part of the works conserve an archetype. This study presented the application of conservation methods on the paper relics which are in the bad condition and obtained information through carbon dating of it.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.301-307
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• 1997

Monodisperse, spherical $SiO_2/TiO_2$ composite fine powders were prepared by modified Sol-Gel process which $TiO_2$ fine Powders was used as a seed particles for condensation of TEOS (Tetraethyl Orthosilicate). The reaction was carried out under $N_2$ atmosphere at ambient temperature using $NH_3$ as a catalyst. Ethanol was used as a solvent. Drying process was carried out with vacuum trap which cooled by liquid $N_2$. The reaction variables were the concentration of TEOS, the concentration of ammonia, the size of $TiO_2$ seed and molar ratio of $SiO_2/TiO_2$. The optimum condition for the preparation of $SiO_2/TiO_2$ composite fine powders without agglomeration was [TEOS]=0.3M, [$NH_3$]=0.7M, size of $SiO_2/TiO_2$ seed = 200~300nm.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.675-680
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• 1990

A near-infrared reflectance spectroscopic(NIRS) method which has been recently developed for a non-destructive method for measuring ingredients in foods and agricultural products especially was evaluated for the determination of capsanthin, total sugar, capsaicin and moisture contents in Korean domestic red peppers. A multiple linear regression analysis with the data obtained by standard-laboratory methods(capsaicin by GC, capsanthin by Colorimetry, total sugar by HPLC and moisture by Vacuum drying method) and NIRS method was carried out to make a calibration. The accuracy of the NIRS method was found to be adequate when the standard-laboratory values for a set of sample that were not included in the calibration, were compared. It is concluded that the NIRS method is suitable for the determination of total sugar and capsanthin.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.471-480
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• 2017

A proton exchange membrane fuel cell (PEMFC) operated at $150^{\circ}C$ was evaluated by a controlling different amount of phosphoric acid (PA) to a membrane-electrode assembly (MEA) without humidification of the cells. The effects on MEA performance of the amount of PA in the cathode are investigated. The PA content in the cathodes was optimized for higher catalyst utilization. The highest value of the active electrochemical area is achieved with the optimum amount of PA in the cathode confirmed by in-situ cyclic voltammetry. The current density-voltage experiments (I-V curve) also shows a transient response of cell voltage affected by the amount of PA in the electrodes. Furthermore, this information was compared with the production variables such as hot pressing and vacuum drying to investigate those effect to the electrochemical performances.

• Nuclear Engineering and Technology
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• v.43 no.4
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• pp.391-398
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• 2011

The U metal chips generated in developing nuclear fuel and a gamma radioisotope shield have been stored under immersion of water in KAERI. When the water of the storing vessels vaporizes or drains due to unexpected leaking, the U metal chips are able to open to air. A new oxidation treatment process was raised for a long time safe storage with concepts of drying under vacuum, evaporating the containing water and organic material with elevating temperature, and oxidizing the uranium metal chips at an appropriate high temperature under conditions of controlling the feeding rate of oxygen gas. In order to optimize the oxidation process the uranium metal chips were completely dried at higher temperature than $300^{\circ}C$ and tested for oxidation at various temperatures, which are $300^{\circ}C$, $400^{\circ}C$, and $500^{\circ}C$. When the oxidation temperature was $400^{\circ}C$, the oxidized sample for 7 hours showed a temperature rise of $60^{\circ}C$ in the self-ignition test. But the oxidized sample for 14 hours revealed a slight temperature rise of $7^{\circ}C$ representing a stable behavior in the self-ignition test. When the temperature was $500^{\circ}C$, the shorter oxidation for 7 hours appeared to be enough because the self-ignition test represented no temperature rise. By using several chemical analyses such as carbon content determination, X-ray deflection (XRD), Infrared spectra (IR) and Thermal gravimetric analysis (TGA) on the oxidation treated samples, the results of self-ignition test of new oxidation treatment process for U metal chip were interpreted and supported.

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.79-85
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• 1967

Kim, Jong Hyup., (Div. of Biology, Atomic Energy Research Institute,Korea.;) Studies on the Cellulor Metabolism in Microorganisms as influenced by Gamma-irradiation(III): On the Changes of Free Amino acid Pool and content of Protein in Yeast clls irradiated by .gamma.-ray. 1. The strain of Saccharomyces cerevisiae had been cultured synchronously in aerobic condition and irradiatel by gamma-ray from the source of cobalt-60. Drying in vacuum oven at $90^{\circ}C$ C over 12 hours, then changes of protein content (Kjeldahl) and free amino acid pool have been assayed with use of spectrophotometer. Results obtained were compared with those of unirradiated normal cells. 2. It is proved that amount of protein content in the irradiated cells increases to seven percent more than those of normal cells in the same weight of dried samples. It seems like carbohydrate breakown had been stimulated by irradiation and that relative contents of protein shows higher values than those of normal in the same weight of samples. 3. The amount of free amino acid pool in the irradiated cells shows less value about ten percent than those of normal cells, and rate of decreasing is also weak than those of standard reagent solution of amino acid. We may assume that free amino acid pool would be protected against radiation damage in living cells and more stable than in vitro. 4. The component of free amino acid pool have been assayed on second dimensional paper chromatogram, and the identified amino acids are as follows; aspartic acid, serine, glutamic acid, cystine, lysine, glycine, threonine, histidine, arginine, tyrosine, phenylalanine, valine and leucine. 5. Distributional presence of free amino acids are identical to that of normal cells except arginine, it is cosumable that radiation effect is univerlsal to all amino acid. However it is obvious that there are differences in radiolabilities of amino acids in irradiated cells.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.35-40
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• 1993

A FET(field effect transistor) type lipid sensor was fabricated uy immobilizing lipase enzyme on the gate of pH-ISFET($SiO_{2}/Si_{3}N_{4}$). A water soluble polymer, polyvinyl alcohol(PVA) was modified with 1-methyl-4-(formyl-styryl) pyridinium methosulfate(SbQ) to give a photosensitive membrane(PVA-SbQ) in which lipase was immobilized. The optimum photolithographic conditions were ; spin coating speed $5,000{\sim}6,000$ rpm. UV exposure time $20{\sim}30$ seconds, developing time in water $30{\sim}40$ seconds, and vacuum drying time 45 min. at room temperature with the suspension containing PVA-SbQ aqueous solution(SbQ 1mol%, 10 wt %) $200{\mu}L$, bovine serum albumin (BSA) 7.5 mg, and lipase 10 mg. The lipid sensor showed good linear calibration curve in the range of $10{\sim}100$ mM triacetin as a lipid sample.

• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.217-223
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• 1988

For the Effective utilization of the fish resources in coastal regions, investigations on preparation of powdered dried arkshell instant soup., quality stability of the products during storage and utilization as a food material were carried out with arkshell, Anadara broughtonii. Three kinds of powdered instant soup were prespared as 0% table salt(A), 5% table salt (B), 15% table salt(C) and packed with vacuum in laminated film bag. (polyester/nylon: 85${mu}ell$/15${mu}ell$, 18$\times$27cm) Their processing conditions and quality stability during storage at room temperature for 90 days were examined. Powdered instant soup was made by washing raw arkshell to remove visceral, clay, sand and blood, hot air drying(60$\pm$1$^{\circ}C$, 20 hrs) after draining and pulverizing dried arkshell to 35 mesh. Powdered instant soup was made by adding 2% sugar 0% table salt (5% and 15% table salt), 10.5% monosodium glutamate, 0.3% black pepper and 0.3% garlic powder to the pulverized dried arkshell. The condition of moisture and water activity of the products were 5.9-6.9% and 0.42-0.43, respectively. The moisture content s , water activity and pH of the products were showed little change and volatile basic nitrogen of them increased slightly during storage. Thiobarbituric acid value increased up to 60 days of storage and then decreased slightly. In solubility, powdered instant soup were showed no remarkable difference comparing with goods on the market. The color value of th products were showed little change during storage, In sensory evaluation, product B were scored slightly higher, in most cased, in flaver, color. taste and overall acceptability comparing with product A or product C during storage. Judiging form the sensory evaluation, powdered instant soup of 5% table salt (B) were the most desirable, and the quality of the products was stable for 90 days at 20$\pm$3$^{\circ}C$.