• Resources Recycling
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• v.3 no.1
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• pp.32-37
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• 1994

Mercury in spent button type batteries can be separated and recovered with vacuum distillation method. It was found that mercury in the battery began to distill at $150^{\circ}C$ and organic substanced like a packing material was decomposed at$ 300^{\circ}C$. More than 99.9% of mercury contained in the battery was distiled and separated at about $250^{\circ}C$ and 20 torr with 8 hours' reaction time. The dissolution tests of the residue after distillation showed that mercury concentration in the solution were lower than 5 ppb and this values satisfied the environ-mental condition. Also as the furnace heating rate was above $15^{\circ}C$/min, it was found that the spent battery was destroyed because of increased pressure in the battery inside.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.315-322
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• 2008

Valves in power plants are leaking internally by various damages including insertion of foreign objects on seat, seat crack, defects and fatigue crack of stem packing or welds etc. due to severe operating conditions such as high temperature and high pressure for extended period time. Acoustic emission(AE) technology should be applied in order to diagnose precisely and evaluate these valve internal leak. In this paper, results of studies which have accomplished in actual power plant are presented. We have analyzed background noise, AE signal level and frequency spectrum through laboratory tests on the basis of various actual conditions in power plant, and also have considered evaluation methods on the background noise, AE properties and the detectable minimum leak rate according to valve leak conditions through comparing with results of field tests in power plant. As a result of these studies, we conformed that evaluation of internal leak conditions including discrimination of leak or not, and the detectable minimum leak rate is possible, and also it is expected to contribute to safe operation and prevention of energy loss in power plants.

• Archives of Craniofacial Surgery
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• v.14 no.1
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• pp.50-52
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• 2013

Povidone-iodine (PVP-I, Betadine) has many advantages as a disinfectant solution for preoperative preparations, especially for oral surgery. It is widely used because of its low toxicity and excellent bactericidal effect. The authors report a case of pneumonia secondary due to the aspiration of PVP-I, which was used as an oral disinfectant. We present a case of aspiration pneumonia that resulted from the careless use of PVP-I during preoperative preparation. The patient was a 10-month-old female scheduled for elective surgery to correct a complete cleft of secondary palate. During the preparation of the oral cavity for that cleft palate patient, PVP-I was incidentally aspirated to the airway. The lung resistance was noted with positive pressure and pneumonic infiltration on chest radiograph was seen. The operation was postponed and the patient underwent respiratory care. Three months later, elective palatoplasty under general anesthesia was performed without complication. Based on the experiences of this case, the authors advise that throat-packing should be placed before oral preparation to prevent serious pulmonary complications.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.71-76
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• 2019

Monochromatic amber phosphor in glasses (PiGs) for automotive LED applications were fabricated with $YAG:Ce^{3+}$, $CaAlSiN_3:Eu^{2+}$ phosphors and Pb-free silicate glass. After synthesis and thickness-thinning process, PiGs were mounted on high-power blue LED to make monochromatic amber LEDs. PiGs were simple mixtures of 566 nm yellow YAG, 615 nm red $CaAlSiN_3:Eu^{2+}$ phosphor and transparent glass frit. The powders were uniaxially pressed and treated again through CIP (cold isostatic pressing) at 200 MPa for 20 min to increase packing density. After conventional thermal treatment at $550^{\circ}C$ for 30 min, PiGs were applied by using GPS (gas pressure sintering) to obtain a fully dense PiG plate. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30 wt% phosphor had full sintered density. Changes in photoluminescence spectra and color coordination were investigated by varying the ratio of $YAG/CaAlSiN_3$ and the thickness of the plates. Considering the optical spectrum and color coordinates, PiG plates with $240{\mu}m$ thickness showed a color purity of 98% and a wavelength of about 605 nm. Plates exhibit suitable optical characteristics as amber light-converting material for automotive LED applications.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.129-135
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• 2021

Injection molding is a manufacturing method of melting the polymer resin and injecting it into a mold to molding it into the desired form. Due to the short molding time and outstanding formability, complex products can be shaped with high precision and it is the most widely used polymer molding method. However, there may be areas that are not filled depending on the location of the injection gate where polymer resin is injected. Formability is determined by deformation and surface precision due to the impact of residual stress after molding. Hence, choosing the location of the injection gate is very important and molding analysis of injection molding is essential to reduce the cost of the mold. This study evaluated the injection formability based on the location of the injection gate of the vertical machining center ATC tool port using injection molding analysis and the results were compared and analyzed. Injection molding analysis was conducted on filling, packing, and deformation according to the location of the gate of the ATC tool port. From each injection gate location, filling time, pressure, and maximum deformation were compared. At gate 2, conditions of molding time and the location of the gate were far superior in production and quality. Gate 2 produced the smallest deformation of 0.779mm with the best quality.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.84-90
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• 2022

The purpose of the cover housing component of a car door is to protect the terminals of the plug housing that connects the electric control unit on the door side to the car body. Therefore, for a smooth assembly with the plug housing and to prevent contaminants from penetrating into the gaps that occur after assembly, the warpage of the cover housing should be minimized. In this study, to minimize the warpage of the cover housing, optimization was performed for design factors related to the mold and processes based on the injection molding simulation. These design factors include gate location, gate diameter, injection time, resin temperature, mold temperature, and packing pressure. To optimize the design factors, Taguchi's approach to the design of experiments was adopted. The optimal combination of the design factors and levels that minimize warpage was predicted through L₁₈-orthogonal array experiments and main effects analysis. Moreover, the warpage under the optimal design was estimated by the additive model, and it was confirmed through the simulation experiment that the estimated result was quite consistent with the experimental result. Additionally, it was found that the warpage under the optimal design was significantly improved compared to both the warpage under the initial design and the best warpage among the orthogonal array experimental results, which numerically decreased by 36.9% and 23.4%, respectively.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.1.1-1.4
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• 2024

This article provides comprehensive guidance on the maintenance, cleaning, regeneration, and storage of silica-based HPLC (High-Performance Liquid Chromatography) columns. The general considerations emphasize the importance of using in-line filters and guard cartridges to protect columns from blockage and irreversible sample adsorption. While these measures help, contamination by strongly adsorbed sample components can still occur over time, leading to an increase in back pressure, loss of efficiency, and other issues. To maximize column lifetime, especially with UHPLC (Ultra-High Performance Liquid Chromatography) columns, it is advisable to use ultra-pure solvents, freshly prepared aqueous mobile phases, and to filter all samples, standards, and mobile phases. Additionally, an in-line filter system and sample clean-up on dirty samples are recommended. However, in cases of irreversible compound adsorption or column voiding, regeneration may not be possible. The document also provides specific recommendations for column cleaning procedures, including the flushing procedures for various types of columns such as reversed phase, unbonded silica, bonded normal phase, anion exchange, cation exchange, and size exclusion columns for proteins. The flushing procedures involve using specific solvents in a series to clean and regenerate the columns. It is emphasized that the flow rate during flushing should not exceed the specified limit for the particular column, and the last solvent used should be compatible with the mobile phase. Furthermore, the article outlines the storage conditions for silica based HPLC columns, highlighting the impact of storage conditions on the column's lifetime. It is recommended to flush all buffers, salts, and ion-pairing reagents from the column before storage. The storage solvent should ideally match the one used in the initial column test chromatogram provided by the manufacturer, and column end plugs should be fitted to prevent solvent evaporation and drying out of the packing bed.

• KSBB Journal
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• v.20 no.6
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• pp.458-463
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• 2005

[ $H_2$ ] from CO and water was continuously produced in a trickle bed reactor(TBR) using Citrobacter amalonaticus Y19. When the strain C. was cultivated in a stirred-tank reactor under a chemoheterotrophic and aerobic condition, the high final cell concentration of 13 g/L was obtained at 10 hr. When the culture was switched to an anaerobic condition with the continuous supply of gaseous CO, CO-dependent hydrogenase was fully induced and its hydrogen production activity approached 16 mmol/g cell/hr in 60 hr. The fully induced C. amalonaticus Y19 cells were circulated through a TBR packed with polyurethane foam, and the TBR was operated for more than 20 days for $H_2$ production. As gas retention time decreased or inlet CO partial pressure increased, $H_2$ production rate increased but the conversion from CO to $H_2$ decreased. The maximum $H_2$ production rate obtained was 16 mmol/L/hr at the gas retention time of 25 min and the CO inlet partial pressure of 0.4 atm. The high $H_2$ production rate was attributed to the high cell density in the liquid phase circulating the TBR as well as the high surface area of polyurethane foam used as packing material of the TBR.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.692-701
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• 2008

This study was conducted with 150 adults of 20 years or older, all of whom lived in Seoul. The awareness of traditional Hangwa (Korean cookies) was shown to be relatively low, with 2.9 points on average, and the intake of traditional Hangwa for a month was 2.1 times. For the reason that traditional Hangwa couldn't become popular, and the opinion that the reason was because the price is expensive was the highest, at 3.8. The next highest reasons given were because it is difficult to buy, and because it is inconvenient to eat, at 3.0. The traditional Hangwa was shown to enjoy positive awareness as opposed to negative awareness, while the manufacturing sanitation was also recognized to be relatively clean, with 2.6 points assigned to the opinion that it doesn't taste good, and 2.7 points assigned to the opinion that the manufacturing sanitation is unclean. With regard to the excellence of traditional Hangwa, the response that 'our tradition can be handed down' was the most often encountered, with a score of 3.9. The traditional Hangwa was appraised as excellent, with 3.6 points assigned to the opinion 'it suits our body because it is made with our agricultural products' and 3.4% for each opinion 'safe ingredients are used' and 'all ingredients are good for health'. With regard to the level of agreement for the development of functional traditional Hangwa, the positive group was higher than 25.3% of the negative group, with 27.3% for 'agree very much' and 22.0% for 'agree'. When converted into a 5-point scale for the development of functional traditional Hangwa, the group that was positive toward its development was high, with 3.4 points on average. All categories of excellence awareness were correlated with the level of agreement for the development of a functional food product (p<0.001). Consumer awareness toward the addition of traditional Hangwa functionality was generally positive, with 3.3 points or higher on average, and awareness of the aging suppression and diabetes control effects of Hangwa was also high, with 3.5 points. Next were Hangwa for diet, Hangwa for blood pressure control, Hangwa for mineral supple-mentation and vitamin additive-type Hangwa, with 3.4 for each, and Hangwa for health preservation, with 3.3 in order. With regard to the degree of interest toward functional traditional Hangwa for the treatment of diseases, obese patients cited aging suppression, at 3.2, and vitamin additive Hangwa, at 3.0, while Hangwa for dieting was assigned 2.8 points. Patients with high blood pressure, blood circulation, and diabetes were all shown as having a high degree of interest in all items, while evidencing particular interest toward Hangwa for diabetes control and Hangwa for blood pressure control. With regard to intention to purchase while developing functional traditional Hangwa, the group asserting intention to purchase was higher than 60% for all items except for Hangwa for diabetes control (58.7%). The Hangwa for aging suppression was highest, at 68.6%, and shown as having intention to purchase during development in the order of vitamin additive Hangwa at 68.0%, Hangwa for mineral supplementation at 64.6%, each of Hangwa for health preservation and Hangwa for blood pressure control at 62.7%, Hangwa for diet at 62.6% and Hangwa for diabetes control at 58.7%. The considerations during the development of functional traditional Hangwa were in the following order: storage at 4.1 points, taste and level of function at 3.9 points, size at 3.5 points, and packing at 3.4 points.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.210-216
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• 2007

A study was conducted to find mechanism and spray characteristics of a mini-sprinkler with downward spray to develop a new design type to be able to prevent drop water. The experiments were executed in a plastic greenhouse to minimize the effect of the wind. Data was collected at five different operation pressures and at 4 different raiser heights. Spray characteristics of the sprinkler such as effective radius, effective area, mean application depth, absolute maximum application depth, effective maximum application depth and coefficient of variation were determined. In order to analyze the mechanism and packing supporter of sprinkler, the numerical simulation using ABAQUS was performed. The optimum pressure for preventing drop water was determined.