• Asian Journal of Atmospheric Environment
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• v.7 no.1
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• pp.17-24
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• 2013

Fog deposition onto the cool-temperate deciduous forest around Lake Mashu in northern Japan was estimated by the inferential method using the parameterizations of deposition velocity and liquid water content of fog (LWC). Two parameterizations of fog deposition velocity derived from field experiments in Europe and numerical simulations using a detailed multi-layer atmosphere-vegetation-soil model were tested. The empirical function between horizontal visibility (VIS) and LWC was applied to produce hourly LWC as an input data for the inferential method. Weekly mean LWC computed from VIS had a good correlation with LWC sampled by an active string-fog collector. By considering the enhancement of fog deposition due to the edge effect, fog deposition calculated by the inferential method using two parameterizations of deposition velocity agreed with that computed from throughfall data. The results indicated that the inferential method using the current parameterizations of deposition velocity and LWC can provide a rough estimation of water input due to fog deposition onto cool-temperature deciduous forests. Limitations of current parameterizations of deposition velocity related to wind speed, evaporation loss of rain and fog droplets intercepted by tree canopies, and leaf area index were discussed.

• YAKHAK HOEJI
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• v.36 no.2
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• pp.159-166
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• 1992

A neoglycolipid, N-stearyl lactobionamide(N-SLBA) was synthesized and the incorporation of the neoglycolipid into liposomes was achieved in order to prepare neo-galactosylated liposome as potential drug carrier for active targeting to galactose receptor existing cell and tissue. N-SLBA was synthesized by the covalent linkage between carboxyl group of lactobionic acid and amino group of stearylamine(SA). The yield of N-SLBA was about 52.3%. It was identified with $1650\;cm^{-1}$ in IR chart, 7.5 ppm in NMR spectra, $61^{\circ}C$ endothermic peak in DSC heating curve. Surface-modified large unilamellar vesicle with galactose(N-SLBA-LUV) could be prepared with N-SLBA by reverse evaporation method. N-SLBA-LUV was identified by TEM and measuring of membrane function. The maximum amount of N-SLBA incorporated into liposome is up to about 15 mol%. Compared with control liposome (SA-LUV), N-SLBA-LUV showed lower encapsulation efficiency of MTX. It might due to the loss of positive surface charge of stearylamine. N-SLBA-LUV was similar to SA-LUV in aspect of osmotic behavior. N-SLBA-LUV prepared with N-SLBA would be expected to be a good carrier for active targeting to galactose receptor existing cell and tissue.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.30-38
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• 1998

A new frequency weighing sensor was applied to grow Bi12GeO20 crystals in the auto-di-ameter control system of Czochralski method. The rotation rate was varied in the range of 23 to 21 rpm to preserve flat interface in a given heat configuration. To prevent the constitutional super-cooling from the evaporation loss, 105% stoichiometric amount of Bi2O3 was employed, equivalent to 6.18 molar ratio of Bi2O3 to GeO2. Transparent and light brown Bi12GeO20 single crystal in uniform diameter was grown. The dislocation density was determined to be 103/cm2 corresponding to the optical quality in commercial applications. The grown crystal measured diameter 25 mm and length 70 mm and the preferred growth direction was confirmed to be <110>.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.251-257
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• 2018

There are various quality deteriorations of concrete such as plastic, drying shrinkage due to abrupt moisture evaporation, slump loss and cold joint under hot weather condition. To protect from above deteriorations, several kinds of modified bubble sheets have been applied to secure heat insulation performance. But, there is not enough application cases of bubble sheets at job site under hot weather condition. The objective of the paper is to investigate the temperature profile and crack occurrence of the concrete covered with five different kinds of surface curing sheets, which is placed under hot weather condition. Single layer transparent bubble sheet, white colored bubble sheet, aluminum metalizing bubble sheet and PE film are adopted for surface curing sheets. Test results indicated that application of aluminum metalizing bubble sheet had most favorable effect on the reduction of on temperature rise and on the crack reduction of concrete. But due to larger reflection of light by aluminum, it brings about visual pollution to the workers. Hence, the application of white colored bubble sheet can be the most desirable alternative to protect the concrete from hot weather in the field.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.9-14
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• 2015

We investigated the sweating response during passive heating (partial submersion up to the umbilical line in $42{\pm}0.5^{\circ}C$ water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, $25.6{\pm}1.8^{\circ}C;$ relative humidity (RH), $82.1{\pm}8.2%$] and in January during the winter, 2012 (winter-SA; temp, $-2.7{\pm}2.9^{\circ};$ RH, $65.0{\pm}13.1%$) in Cheonan ($126^{\circ}52^{\prime}N$, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, $25.0{\pm}0.5^{\circ}C$: RH, $60.0{\pm}3.0%$). Fifteen healthy men (age, $23.4{\pm}2.5$ years; height, $175.0{\pm}5.9cm;$ weight, $65.3{\pm}6.1kg$) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p<0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p<0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.200-203
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• 2003

A study on the arc resistance and light reflectance of PTFE (polytetrafluoroethylene) nozzle for circuit breaker is presented. PTFE has been used widely as a material for circuit breaker nozzle. PTFE has excellent electrical resistivity, high melt viscosity, chemical inertness, heat resistance and low loss factor. PTFE melts at $327\;^{\circ}C$ but the viscosity is very high above the melting point. In the arcing environment in a circuit breaker, the fraction of the power is emitted out of the arc and reaches the nozzle wall by radiation, causing ablation at the surface and in the depth of the wall. Some fraction of the radiation power emitted out of the arc directly break up the chemical bonds at the surface while some fraction of the radiation power penetrates into the wall, heats up the material to evaporation temperature and causes damages deeper inside the volume of the nozzle. In this paper, some fillers that have endurance in the high temperature arc environment were added into PTFE. Adding some fillers into PTFE was expected to be efficient in improving the endurability against radiation. The light reflectance and arc resistance of PTFE composites were investigated.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1420-1430
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• 2018

We investigate an entangled system, which is analogous to a composite system of a black hole and Hawking radiation. If Hawking radiation is well approximated by an outgoing particle generated from pair creation around the black hole, such a pair creation increases the total number of states. There should be a unitary mechanism to reduce the number of states inside the horizon for black hole evaporation. Because the infalling antiparticle has negative energy, as long as the infalling antiparticle finds its partner such that the two particles form a separable state, one can trace out such a zero energy system by maintaining unitarity. In this paper, based on some toy model calculations, we show that such a unitary tracing-out process is only possible before the Page time while it is impossible after the Page time. Hence, after the Page time, if we assume that the process is unitary and the Hawking pair forms a separable state, the internal number of states will monotonically increase, which is supported by the Almheiri-Marolf-Polchinski-Sully (AMPS) argument. In addition, the Hawking particles cannot generate randomness of the entire system; hence, the entanglement entropy cannot reach its maximum. Based on these results, we modify the correct form of the Page curve for the remnant picture. The most important conclusion is this: if we assume unitarity, semi-classical quantum field theory, and general relativity, then the black hole should violate the Bekenstein-Hawking entropy bound around the Page time at the latest; hence, the infinite production arguments for remnants might be applied for semi-classical black holes, which seems very problematic.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.69-69
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• 2019

The distillation of liquid cathode is necessary to separate cadmium from the actinide elements in the pyroprocessing since the actinide deposits are dissolved or precipitated in a liquid cathode. It is very important to avoid a splattering of cadmium during evaporation due to the high vapor pressure. Several methods have been proposed to lower the splattering of cadmium during distillation. One of the important methods is an installation of crucible cover on the distillation crucible. A multi-layer porous round cover was proposed to avoid a cadmium splattering in our previous study. In this study, the effect of crucible cover on the cadmium distillation was examined to develop a splatter shield. Various surrogates were used for the actinides in the cadmium. The surrogates such as bismuth, zirconia, and tungsten don't evaporate at the operational temperature of the Cd distiller due to their low vapor pressures. The distillation experiments were carried out in a crucible equipped with cover and in a crucible without cover. About 40 grams of Cd was distilled at a reduced pressure for two hours at various temperatures. The mixture of the cadmium and the surrogate was heated at $470{\sim}620^{\circ}C$. Most of the bismuth remained in the crucible equipped with cover after distillation under $580^{\circ}C$ for two hours, whereas small amount of bismuth decreased in the crucible without cover above $580^{\circ}C$. The liquid bismuth escaped with liquid cadmium drop from the crucible without cover. It seems that the crucible cover played a role to prevent the splash of the liquid cadmium drop. The effect of the cover was not clear for the tungsten or zirconia surrogate since the surrogates remained as a solid powder at the experimental temperature. From the results of this work, it can be concluded that the crucible cover can be used to minimize the deposit loss by prevention of escape of liquid drop from the crucible during distillation of liquid cathode.

• 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.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.134-134
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• 2010

Fuel cell is a device that directly converts chemical energy in the form of a fuel into electrical energy by way of an electrochemical reaction. In the anode for a high temperature fuel cell, nickel or nickel alloy has been used in consideration of the cost, oxidation catalystic ability of hydrogen which is used as fuel, electron conductivity, and high temperature stability in reducing atmosphere. Most MCFC stacks currently operate at an average temperature of $650^{\circ}C$. There is some gains with decreased temperature in MCFC to diminish the electrolyte loss from evaporation and the material corrosion, which could improve the MCFC life. However, operating temperature has a strong related on a number of electrode reaction rates and ohmic losses. Baker et al. reported the effect of temperature (575 to $650^{\circ}C$). The rates of cell voltage loss were 1.4mV/$^{\circ}C$ for a reduction in temperature from 650 to $600^{\circ}C$, and 2.16mV/$^{\circ}C$ for a decrease from 600 to $575^{\circ}C$. The two major contributors responsible for the change in cell voltage with reducing operation temperature are the ohmic polarization and electrode polarization. It appears that in the temperature range of 550 to $650^{\circ}C$, about 1/3 of the total change in cell voltage with decreasing temperature is due to an increase in ohmic polarization, and the electrode polarization at the anode and cathode. In addition, the oxidation reaction of hydrogen on an ordinary nickel alloy anode in MCFC is generally considered to take place in the three phase zone, but anyway the area contributing to this reaction is limited. Therefore, in order to maintain a high performance of the fuel cell, it is necessary to keep this reaction responsible area as wide as possible, that is, it is needed to keep the porosity and specific surface area of the anode at a high level. In this study effective anodes are prepared for low temperature MCFC capable of enhancing the cell performance by using zirconium hydride at least in part of anode material.