• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.168-177
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• 2017

Strain A28-5, which can degrade xylan and agar in solid medium, was isolated from a coastal seawater sample collected from Jeju Island, South Korea. This strain was found to be a gram-negative, $Na^+$-requiring bacterial strain with a polar flagellum for motility. Additionally, the strain was tolerant to antibiotics such as ampicillin and thiostrepton. The G+C content of the genome was 43.96% and menaquinone-7 was found to be the predominant quinone. Major fatty acids constituting the cell wall of the strain were $C_{16:1}$ ${\omega}7c/iso-C_{15:0}$ 2-OH (23.32%), $C_{16:0}$ (21.83%), and $C_{18:1}$ ${\omega}7c$ (17.98%). The 16S rRNA gene sequence of the strain showed the highest similarity (98.94%) to that of Catenovulum agarivorans YM01, which was demonstrated by constructing a neighbor-joining phylogenetic tree. A28-5 was identified as a novel species of the genus Catenovulum via DNA-DNA hybridization with Catenovulum agarivorans YM01, and thus was named as Catenovulum jejuensis A28-5. The formation of tetramers and hexamers of xylooligosaccharides and (neo)agarooligosaccharides, respectively, were confirmed by thin-layer chromatography analysis using an enzyme reaction solution containing xylan or agarose with two crude enzymes prepared from the liquid culture of the strain.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.6
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• pp.493-501
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• 2000

The microstructure and electrical properties of ZnO-Pr$_{6}$/O$_{11}$-CoO-Er$_{2}$/O$_{3}$ based varistors were investigated with Er$_{2}$/O$_{3}$ additive content of the range 0.0 to 2.0 mol%. Most of the added Er$_{2}$/O$_{3}$ were segregated at the nodal points and grain boundaries and it coexisted with Pr$_{6}$/O$_{11}$ in the bulk intergranular layer. The average grain size was decreased in the range of 7.44 to 5.62${\mu}{\textrm}{m}$ at 130$0^{\circ}C$ and 18.36 to 9.11 at 135$0^{\circ}C$ with increasing Er$_{2}$/O sub 3/ additive content. The density of ceramics was in the range 4.87 to 5.08 g/cm$^3$ at 130$0^{\circ}C$ and 5.35 to 5.62 g/cm$^3$at 135$0^{\circ}C$. At 130$0^{\circ}C$ the varistors without Er$_{2}$/O$_{3}$ exhibited 29.66 in the nonlinear exponent and 28.23 $\mu$A in the leakage current whereas the varistors with 0.5 mol% Er$_{2}$/O$_{3}$ exhibited a high nonlinearity which is 52.78 in thenonlinear exhibited and 9.75 $\mu$A in the leakage current. At 135$0^{\circ}C$ the varistors without Er$_{2}$/O$_{3}$ exhibited a very poor nonlinearity indicating 2.08 in the nonlinear exponent and 133.79 $\mu$A in the leakage current whereas the varistors with 1.0mol% Er$_{2}$/O$_{3}$ exhibited a relatively high nonlinearity which is 36.79 in the nonlinear exponent and 5.92 $\mu$A in the leakage current. Therefore Er$_{2}$/O$_{3}$ was additive which greatly improve the nonlinearity. It is believed that ZnO-0.5 mol% Pr$_{6}$/O$_{11}$-1.0 mol% CoO-0.5 mol% Er$_{2}$/O$_{3}$ based ceramicss will be usefully used as a basic composition to develop the advanced pr$_{6}$/O$_{11}$-based ZnO varistors.ristors.ristors.

• Journal of Korea Water Resources Association
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• v.42 no.1
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• pp.9-19
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• 2009

This study presents the effects of temporally varied groundwater table on hydrological components such as surface runoff, evapotranspiration, and soil water content. To this end, the SWAT-MODFLOW model in which the groundwater module of SWAT is replaced with MODFLOW model has been used with a modification to enhance the coupling between the water content in soil profile and the groundwater in shallow aquifer. The variable soil layer construction technique (VSLT) is developed in the present work to represent the direct interaction of soil water and groundwater more realistically, and then the VSLT is incorporated into SWAT-MODFLOW model. In VSLT, when the simulated groundwater table rises within the soil zone, the soil layers below the water table is regarded as a portion of the shallow aquifer, so that those layers are excluded from the initially defined soil zone and are governed by the MODFLOW. From the simulation tests for the Musim river basin, the improved SWAT-MODFLOW model with VSLT is found to correctly evaluate the spatial distributions of overland flow, soil moisture, evapotranspiration according to the groundwater table variation.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.3
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• pp.1-5
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• 2018

In this study, the effects of indium (In) doping in InGaN/GaN multi quantum well (MQW) on photoelectrochemical (PEC) properties were investigated. Each quantum well (QW) layer with controlled In content were grown on sapphire substrate. Before growth of MQW, GaN growth consisted of various stages in the following order: buffer GaN growth, undoped GaN growth, and Si-doped n-type GaN growth. Absorbance of InGaN/GaN MQW having different In composition was higher than that of the InGaN/GaN MQW having a constant In composition. It indicates that InGaN layer having different In composition absorbs light having a broad spectrum energy. These results are in agreement with those in photoluminescence (PL). After evaluation of PEC properties, it demonstrated that InGaN/GaN MQW having different In composition was improved InGaN/GaN MQW having constant In composition in PEC water splitting ability.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.369-369
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• 2017

To improve the reclaimed land soil, we put organic materials (Chopped kenaf, decomposed rice hull, rice straw, pellet type manure compost) into reclaimed land for 3,000 kg per 10a. As a result, EC of reclaimed soil was lowered by 58% ($1.2dS/m{\rightarrow}0.5$), content of soil organic material was risen from 6.7 g/kg to 16.0 (1.4 fold ${\uparrow}$), porosity of soil was elevated from 1.57 % to 1.31 (16.6% ${\downarrow}$), soil hardness was reduced from 20.2 mm to 17.9 (11.4% ${\downarrow}$) and plow layer soil was deepen from 19.8 cm to 26.8 (35% ${\uparrow}$). In the wake of physiochemical improvement of reclaimed soil, the growth phase of crops became better contrast to non-treatment. For example the plant height of Kenaf (Hibiscus cannabinus L.) cultivated in reclaimed land containing organic materials was lengthen by 18.8%. Especially, the improvment effect of pellet type manure compost and rice straw was more preferable. When the kenaf was cultivated in reclaimed land containing organic materials, the yield was become higher. The average yield of organic materials treatment was 9,218 kg/10a, and it was 2.1 times higher than non-treatment (4,368kg/10a). And the effective treatments to increase yields were pellet type manure compost (10,848 kg/10a, 148% ${\uparrow}$), rice straw (120% ${\uparrow}$) and chopped kenaf (95% ${\uparrow}$). To intensify the effect of physicochemical enhancement of reclaimed land soil and improving yields, we put into various physical types of organic materials (pellet type, liquid type, powdered type). The most effective organic materials type for enhancement of physicochemical properties (EC of reclaimed soil was lowered, content of soil organic material was risen, porosity of soil was elevated, soil hardness was reduced, plow layer soil was deepen) was pellet. And source to maintain better growth phase and get more yield were liquid and pellet types. When we used pellet type organic material, the plant height of kenaf was lengthen by 41% in comparison with non-treatment and yield was more than 122% more. And also liquid type could get more yield (by 127%) and growth phase (by 38%)

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.33-36
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• 2007

In recent years the convective-dispersive equation has been often discredited in predicting subsurface solute transport under field conditions due to presence of preferential flow paths. Kim et al. (2005) proposed a simple equation that can predict the breakthrough of solutes without excessive data requirements. In their Generalized Preferential Flow Model (GPFM), the soil is conceptually divided in a saturated "distribution layer" near the surface and a "conveyance zone" with preferential flow paths below. In this study, we test the model with previously published data, and compare it with a classical convective-dispersive model (CDM). With three parameters required-apparent water content of the distribution zone, and solute velocity and dispersion in the conveyance zone-GPFM was able to describe the breakthrough of solutes both through silty and sandy loam soils. Although both GPFM and CDM fitted the data well in visual, variables for GPFM were more realistic. The most sensitive parameter was the apparent water content, indicating that it is the determining factor to apply GPFM to various soil types, while Kim et al. (2005) reported that changing the velocity of GPFM reproduced solute transport when same soils were used. Overall, it seems that the GPFM has a great potential to predict solute leaching under field conditions with a wide range of generality.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.74-80
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• 2015

Skin is the soft outer covering of vertebrates that provides protection from pathogenic infection, physical damage, or UV irradiation, and controls body temperature and water content. In this study, we examined the effects of oral intake of kimchi-derived Lactobacillus plantarum K8 lysates on skin moisturizing. In an in vitro study, we observed that the hyaluronic acid content increased in HaCaT cells treated with L. plantarum K8 lysates. Oral administration of L. plantarum K8 lysates effectively attenuated the horny layer formation and decreased epidermal thickening in DNCB-treated SKH-1 hairless mice skin. The damage to barrier function was reduced after 8 weeks of oral administration of L. plantarum K8 lysates as compared with that in the atopic dermatitis mice. For the test with volunteers, we manufactured experimental candy containing 2.1% L. plantarum K8 lysates, while control candy did not contain bacterial lysate. A significant increase in hydration in the experimental candy-administered group as compared with the control candy-administered group was observed on the face after 4 and 8 weeks, and on the forearm after 4 weeks. Decreases in horny layer thickness and TEWL value were observed on the face and forearm of the experimental group. Together, the in vitro cell line and in vivo mouse studies revealed that L. plantarum K8 lysates have a moisturizing effect. A clinical research study with healthy volunteers also showed an improvement in barrier repair and function when volunteers took L. plantarum K8 lysates-containing candy. Thus, our results suggest that L. plantarum K8 lysates may help to improve skin barrier function.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.682-690
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• 2014

In order to improve the thermal stability of wood plastic composites (WPC), thermal degradation behavior of WPC in this study was investigated by the addition of wood flour and fire retardant after hybridization of wood flour and ammonium polyphosphate (APP) into polypropylene (PP) matrix. Thermal degradation behavior of all formulations was analyzed with thermogravimetric analyzer under nitrogen environment at heating rate of $10^{\circ}C/min$. As the thermal degradation temperature of wood flour is lower than that of PP, char layer formed by the wood flour decreases the speed of heat transfer to PP. In addition, the char layer increases the 2nd thermal degradation temperature and decreases the 2nd thermal degradation speed. The WPC treated with APP increases the 1st and 2nd degradation temperatures. In the case of WPC with high loading level of wood flour, the 1st thermal degradation temperature and 2nd thermal degradation rate were increased by the addition of APP, and then the amount of remnants at high temperature was increased by the increase of the APP loading level. In the case of WPC treated with APP, the amount of the remnants at high temperature was increased with the increase of wood flour content from 10 wt% to 50 wt%, indicating that char formation of the APP and wood flour occurred at the same time, resulting in high thermal stability effect by the increase of wood flour content.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.374-384
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• 2020

Two experiments were conducted to determine apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and ileal digestible amino acid (AA) content of brown rice (BR) and to investigate the effect of dietary supplementation of BR on laying performance and egg quality of laying hens. In Exp. 1, 72 Hy-line Brown layers (49-week-old) were allocated to two treatments using a completely randomized block design, and each treatment included six cages per treatment and six hens per cage. A semi-purified diet was formulated to include BR as the sole source of AA and energy and an N-free diet was used to determine basal endogenous loss of AA. The hens were fed a commercial layer diet for adaptation to the experimental environment and diet for 7 days from d 0, and then fed experimental diets for 5 days from d 7. Excreta were collected from d 10 to 11 and ileal digesta were collected on d 12. On a dry matter (DM) basis, the AME and AMEn of BR was determined at 3,773 and 3,729 kcal/kg, respectively. The apparent ileal digestibility (AID) of BR ranged from 32.7% for Thr to 73.7% for Arg. The range of the standardized ileal digestibility (SID) value was between 79.4% for Met and 96.6% for Lys. In Exp. 2, 252 Hy-line Brown layers (44-week-old) were divided into four groups, comprising seven replicates of nine birds each and assigned to four experimental diets containing 0 (Control), 5%, 10%, or 15% BR for 5 weeks. The BR-containing diets were formulated to be equal in the content of AMEn and digestible AA to those of the diet without BR. No significant differences were observed in laying performances. Egg quality and blood profiles were not linearly or quadratically affected by dietary treatments. These results suggest that up to 15% BR can be included into layer feed without any adverse effects on laying performance and egg quality, if its energy and digestible AA values are well evaluated.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.383-390
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• 1992

In the periods of July 31 to August 10. 1988 and March 9 to 13. 1989. sediment samples were collected from the South Sea stations (010] to 092]) located in the area from $N 32^{\circ}$/30' to $34^{\circ}$/30', of latitude and from E $123^{\circ}$ 30' to $128^{\circ}$30' of longitude. These samples were analyzed for the number of total heterotrophic bacteria and extracellular digesting enzyme activities. In the 1989 spring period the number of heterotrophic bacteria in the sediment surface layer was increased more than 100 times at the maximum compared to that in the 1988 summer period. The proportion of fresh water bacteria to total heterotrophic bacteria was also higher in the spring period than the summer period. The extracellular digesting enzyme activities were higher in spring season than summer. Although the water content of sediment in the spring period was lower than that the summer period. the ash weight indicating organic material content was higher. These results means that the diameters of sediment particles were larger in spring than summer but the input of organic material into the sediment was greater. Based on these results bacterial distributions in the sediment layer of South Sea depend greatly on the season due to the effect of fresh water. During the spring season plankton could grow extensively owing to the inorganic nutrients input by the vertical mixing in the water column, then be precipitated into the sediment. Organic nutrients supplied from enzymatic degradation of polymeric particle from plankton can increase the bacterial number, too.