• Journal of the Korean GEO-environmental Society
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• v.15 no.12
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• pp.61-69
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• 2014

Carboxymethyl-${\beta}$-cyclodextrin (${\beta}$-CMCD), as a biodegradable surfactant with hydrophobic and hydrophilic properties, has potential advantages of being applicable to the simultaneous treatment of multiple contaminated soils. In this study, the desorption behaviors of r adionuclides such as cobalt (Co), strontium (Sr), and cesium (Cs) from the soil contaminated with them were experimentally investigated and the effectiveness of CMCD as a desorbent was evaluated. The desorption equilibrium of used radionuclides could be achieved within 1~3 hr and the desorption ratio from kaolin was higher than that from natural soil. The addition of CMCD of 2 g/L increased the desorption ratio by 5~20 % and the desorption ratio of used r adionuclides was shown in the order of Co > Cs > Sr. The experimental desorption data were fitted successfully by pseudo-second order kinetic model and the desorption rate of the r adionuclides was shown in the order of Cs > Co > Sr. Hysteresis between adsorption and desorption of the r adionuclides, as shown in the order of Sr > Co > Cs, increased as the desorption rate decreased. Consequently, it could be considered that the desorption rate was one of the significant factors of the hysteresis. The addition of CMCD as desorbent increased the amount of desorbed radionuclides and decreased the hysteresis. However, the CMCD could not completely desorb the radionuclides from soils even though the excess of CMCD was added.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.34-50
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• 2012

This study conducted the empirical analysis of the influence that are quality attributes, and strengths, weaknesses, low ranking and excess of Korean restaurants menu on revisit intention based on differences between importance and satisfaction by surveying Korean students in Paris, and also conducting IPA analysis based on survey result. The result of IPA analysis showed weaknesses that are the visual elements of foods; in contrast it showed strengths that are the price, temperature, taste, quantity, cleanliness, freshness, and flavor of dishes. Also it showed low ranking that are seasonal items, authenticity, originality, sizes, colors, texture, explanations, ingredients, recipes of menu, classification of healthy food, suitability of bowls, creativity of existing food. Therefore, it is found that the higher recognition of attributes, organic functions, properties, and explanations of menu, the higher revisit intention. It showed that explanations, sensibility, characters, quality of menu influenced on revisit intention according priority by analysis of quality attributes of menu on revisit intention. This study is significant in that it provides useful data services for marketing strategies and operational suggestions to globalization of Korean food by analysis local menu of Korean food service industry.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.113-120
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• 1985

A filed experiment was carried out to investigate the effects for growth, yield of red lopper (Saelona) and properties of soil by beer sewage sludge application to the sandy loam which fertility was common. The results obtained were summerized as follows. 1. Growth of red pepper in sludge plot was very poor by drought in early stage, but color of loaves was green and growth strength was better than nontreated plot after rainfall in last stage. There were no significant differencies between plant height, number of branch on main stem and stem height in sludge and standard plot. 2. Yield of matured red pepper per plant in NPK+, and PK+ sludge 1200kg, 2400kg and 4800kg/10a plot were less than those in standard plot respectively. 3. Ratio of dry weight of matured red pepper in NPK+, and PK+ sludge 1200kg, 2400kg and 4800kg/10a were high than those in standard plot appreciably. 4. Sewage sludge application (1200kg/10a. N=51kg) was available as nitrogen source of organic fertilizer considerably, but there were some growth inhibition by excess of amount applied. 5. Sewage sludge application decreased the pH of the soil and increased the content of organic matter and exchangeable babe in the soil appreciably.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.2-11
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• 2006

In the processes of hydrological cycle, when precipitation reaches the ground surface, water may become surface runoff or infiltrate into soil and then possibly further percolate into groundwater aquifer. A part of the water is returned to the atmosphere through evaporation and transpiration. Soil moisture dynamics driven climate fluctuations plays a key role in the simulation of water transfer among ground surface, unsaturated zone and aquifer. In this study, a one-layer canopy and a four-layer soil representation is used for a coupled soil-vegetation modeling scheme. A non-zero hydraulic diffusivity between the deepest soil layer modeled and groundwater table is used to couple the numerical equations of soil moisture and groundwater dynamics. Simulation of runoff generation is based on the mechanism of both infiltration excess overland flow and saturation overland flow nested in a numerical model of soil moisture dynamics. Thus, a comprehensive hydrological model integrating canopy, soil zone and aquifer has been developed to evaluate water resources in the plain region of Huaihe River basin in East China and simulate water transfer among precipitation, surface water, soil moisture and groundwater. The newly developed model is capable of calculating hydrological components of surface runoff, evapotranpiration from soil and aquifer, and groundwater recharge from precipitation and discharge into rivers. Regional parameterization is made by using two approaches. One is to determine most parameters representing specific physical values on the basis of characterization of soil properties in unsaturated zone and aquifer, and vegetations. The other is to calibrate the remaining few parameters on the basis of comparison between measured and simulated streamflow and groundwater tables. The integrated modeling system was successfully used in the Linhuanji catchment of Huaihe plain region. Study results demonstrate that (1) on the average 14.2% of precipitation becomes surface runoff and baseflow during a ten-year period from 1986 to 1995 and this figure fluctuates between only 3.0% in drought years of 1986, 1988, 1993 and 1994 to 24.0% in wet year of 1991; (2) groundwater directly deriving from precipitation recharge is about 15.0% t of the precipitation amount, and (3) about half of the groundwater recharge flows into rivers and loses through evaporation.

• Herbal Formula Science
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• v.12 no.2
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• pp.47-55
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• 2004

Wang Cheong-Im(1768-1831) in the Ching dynasty conducted the therapy of blood statis syndrome using the methods for promoting blood circulation and removing blood statis in accordance with the description in the book Uirimgaechak(醫林改錯). Thus, this study examined his methods for promoting blood circulation and removing blood statis, therapy of blood statis syndrome and mechanism of function. Since the blood statis symptoms varied on the parts where the blood statis were occurred, the therapy for promoting blood circulation and removing blood statis applied different treatments and drugs depending on the symptoms. The therapy also valued much of qi and blood. Qi is important to the human body so that the therapy replenished qi and simultaneously promoted the blood circulation as mainly focusing on the regulation of the qi flow. Moreover, the therapy adjusted the level of removing blood circulation and rate of replenishing qi. The degree of prescription and drug was differentiated in treating a variety of blood statis because of the difference in the seriousness and characteristics of blood circulation, amount and application of drug and combination of drugs. The therapy was careful about the regulation of qi for the replenishment of qi and the nurishment of blood for the promotion of blood circulation. If the blood circulation was blocked, the blood statis was formed. Accordingly, the phlegm and the blood statis were closely related. Then, the phlegm and blood statis were simultaneously treated. The therapy divided the properties of blood statis into the stagnant excess syndrome, the stagnant deficiency syndrome, the stagnant cold syndrome and the stagnant heat syndrome and treated the patients suitable for each symptom. The function of mechanism in the treatment using the methods for promoting blood circulation and removing blood statis was divided into the stagnation of blood and interruption in blood circulation. The therapy laid stress on promoting blood circulation and removing blood circulation. With such emphasis, the therapy facilitated the circulation in the bloood vessel, prevented the coagulation of blood, removed the blood statis and promoted the metabolism. Then, the physiological function and pathological change internal organs were improved. Furthermore, the therapy strengtened the heart and promoted the blood circulation by improving the systemic blood circulation. Moreover, the therapy facilitated the micro-circulation by adjusting the balance of body.

• Ocean and Polar Research
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• v.33 no.4
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• pp.435-445
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• 2011

We investigated geochemical properties, and microbial sulfate- and iron(III) reduction in sediment influenced by the aquaculture of abalone in the Nohwa-do, southern coastal sea in Korea. Concentrations of ammonium, phosphate, and sulfide in the pore-water were higher at farm sites than at control sites. The differences between the 2 types of sites were most apparent in terms of the weights of abalone and the temperature increase during September. Accordingly, the rates of sulfate reduction at the farm sites during September (61 mmol S $m^{-2}d{-1}$) were 3-fold higher than the sulfate reduction during May (20 mmol S $m^{-2}d{-1}$). In contrast, Fe(III) reduction rates were highest at the control sites in May, but its significance was relatively decreased at farm sites during September when sulfate reduction rates were highest. During September, benthic ammonium flux was 3-fold greater at the farm sites (35 mmol N $m^{-2}d{-1}$) than at the control sites (12 mmol N $m^{-2}d{-1}$), and phosphate flux was 8-fold higher at the farm sites (0.018 mmol P $m^{-2}d{-1}$) than at control sites (0.003 mmol P $m^{-2}d{-1}$). Overall results indicated that the inappropriate operation of a large-scale aquaculture farm may result in excess input of biodeposits and high nutrient fluxes from the sediment, thereby decreasing diversity of the benthic ecosystem and deepening eutrophication in coastal waters.

• Korean Journal of Optics and Photonics
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• v.31 no.5
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• pp.213-217
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• 2020

In this study we report a wet-etching-based fabrication method for adiabatic optical-fiber tapers (OFTs), and describe their adiabaticity and HE₁₁ mode evolution at a wavelength of 1550 nm. The profile of the fabricated system satisfies the adiabaticity properties well, and the far-field pattern from the etched OFT shows that the fundamental HE₁₁ mode is maintained without a higher-order mode coupling throughout the tapers. In addition, the measured far-field pattern agrees well with the simulated result. The proposed adiabatic OFTs can be applied to a number of photonic applications, especially fiber-chip packages. Based on the fabricated adiabatic OFT structures, the optical transmission to the inversely tapered silicon waveguide shows large spatial-dimensional tolerances for 1 dB excess loss of ~60 ㎛ (silicon waveguide angle of 1°) and insertion loss of less than 0.4 dB (silicon waveguide angle of 4°), from the numerical simulation. The proposed adiabatic coupler shows the ultrabroadband coupling efficiency over the O- and C-bands.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1095-1100
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• 2014

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were $40^{\circ}C-45^{\circ}C$ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at $10^{\circ}C-40^{\circ}C$. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.155-164
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• 2005

The characteristics of sintering for Mullite-Cordierite (MC) composites and the effect of $TiO_2$ addition were studied. The MC composites were manufactured by a solution-polymerization method using PVA as a polymer carrier, and $TiO_2$ was used as a sintering agent. They were calcined at $1300^{\circ}C$, planetary milled for 4 h and sintered at $1450^{\circ}C$. As cordierite content increased, relative density of materials was increased up to $98\%$ and sinterability was improved. In case of $50\;wt\%$ mullite/$5\;wt\%$ cordierite composition sintered for 16 h, the flexural strength and thermal expansion coefficient were 190 MPa and $3.07{\times}0^{-6}/^{\circ}C$, respectively. However, mechanical properties were decreased with the cordierite contents higher than $50\;wt\%$ because of the excess liquid-phase amount. As the addition of $TiO_2$ is increased, columnar crystal of mullite and liquid-phase contents were increased. In particular, the flexural strength and thermal expansion coefficient decreased in case of $5\;wt\%\;TiO_2$ addition.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.523-527
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• 2002

LiMn$_2$O$_4$ compounds were synthesized by calcining a mixture of LiOH and MnO$_2$(CMD) at 47$0^{\circ}C$ for 10 h and then calcining again at $650^{\circ}C$ to 90$0^{\circ}C$ fur 48 h in air with intermediate grinding. All the synthesized samples exhibited XRD patterns for the cubic spinel phase with a space group Fd3m. The lattice parameter increased gradually as the sintering temperature rose. The electrochemical cells were charged and discharged fur 20 cycles at a current density 300$\mu$A/$\textrm{cm}^2$ between 3.5 V and 4.3 V. The voltage vs. discharge capacity curves for all the samples showed two plateaus. The LiMn$_2$O$_4$ sample calcined at 90$0^{\circ}C$ had the largest first discharge capacity. This sample exhibited the best crystallinity, had relatively large lattice parameter and had relatively large particles with rectatively homogeneous size. All the samples showed good cycling performances. Among all the samples, the LiMn$_2$O$_4$ calcined at 85$0^{\circ}C$ had relatively large first discharge capacity and very good cycling performance. The addition of excess LiOH and the mixing in ethanol considered to help the formation of the more LiMn$_2$O$_4$ phase per unit weight sample and the more stable LiMn$_2$O$_4$phase. These led to the larger discharge capacities and the better cycling performances. The cyclic voltammograms fur the second cycle of the LiMn$_2$O$_4$ samples showed the oxidation and reduction peaks around 4.05 V and 4.18 V and around 4.08 V and 3.94 V, respectively. The larger first discharge capacity of the sample calcined at the higher temperature is related to the larger lattice parameter.