• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.205-215
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• 2003

A precise and dense Bouguer anomaly is one of the most important data to improve the knowledge of our environment in the aspect of geophysics and physical geodesy. Besides the precise absolute gravity station net, we should consider two parts; one is to improve the precision in gravity measurement and correction of it, and the other is the density of measurement both in number and distribution. For the precise positioning, we have tested how we could use the GPS properly in gravity measurement, and deduced that the GPS measurement for 5 minutes would be effective when we used DGPS with two geodetic GPS receivers and the baseline was shorter than 40km. In this case we should use a precise geoid model such as PNU95. By applying this method, we are able to reduce the cost, time, and number of surveyors, furthermore we also get the benefit of improving in quality. Two kind of computer programs were developed to correct crossover errors and to calculate terrain effects more precisely. The repeated measurements on the same stations in gravity surveying are helpful not only to correct the drifts of spring but also to approach the results statistically by applying network adjustment. So we can find out the blunders of various causes easily and also able to estimate the quality of the measurements. The recent developments in computer technology, digital elevation data, and precise positioning also stimulate us to improve the Bouguer anomaly by more precise terrain correction. The gravity data of various sources, such as land gravity data (by Choi, NGI, etc.), marine gravity data (by NORI), Bouguer anomaly map of North Korea, Japanese gravity data, altimetry satellite data, and EGM96 geopotential model, were collected and processed to get a precise and dense Bouguer anomaly in and around the Korean Peninsula.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.283-287
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• 2007

KIER has been developing the anode-supported flat tubular solid oxide fuel cell unit bundle for the intermediate temperature($700{\sim}800^{\circ}C$) operation. Anode-supported flat tubular cells have Ni/YSZ cermet anode support, 8 moi.% $Y_2O_3$ stabilized $ZrO_2(YSZ)$ thin electrolyte, and cathode multi-layer composed of Sr-doped $LaSrMnO_3(LSM)$, LSM-YSZ composite, and $LaSrCoFeO_3(LSCF)$. The prepared anode-supported flat tubular cell was joined with ferritic stainless steel cap by induction brazing process. Current collection for the cathode was achieved by winding Ag wire and $La_{0.6}Sr_{0.4}CoO_3(LSCo)$ paste, while current collection for the anode was achieved by using Ni wire and felt. For making stack, the prepared anode-supported flat tubular cells with effective electrode area of $90\;cm^2$ connected in series with 12 unit bundles, in which unit bundle consists of two cells connected in parallel. The performance of unit bundle in 3% humidified $H_2$ and air at $800^{\circ}C$ shows maximum power density of $0.39\;W/cm^2$ (@ 0.7V). Through these experiments, we obtained basic technology of the anode-supported flat tubular cell and established the proprietary concept of the anode-supported flat tubular cell unit bundle.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.285-291
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• 2012

Purpose: This study was conducted to identify the surface characteristics of titanium discs coated with MS275/PLGA by electrospray and which is effective to mesenchymal stem cell proliferation. Materials and methods: We used anodized surface coated with PLGA as a control group and anodized surface coated with MS275 $0.5{\mu}M$, $1{\mu}M$, $1.5{\mu}M$ as test groups. To examine that the coating particles are nanometer sized, FE-SEM was used and AFM was utilized to determine the difference of coating surface roughness. We checked the mesenchymal stem cell proliferation by using MTT assay on $1^{st}$, $4^{th}$, $7^{th}$ days. Results: There was no significant difference between control groups and test groups in AFM results (P>.05). In MTT assay results, mesenchymal stem cell proliferation was increased with time, at $7^{th}$ day, cell viability on discs coated with $1.5{\mu}M$ MS275 was significantly higher than control group (P<.05). As SEM showed, the number of cells on all discs was increased and the morphology of cell attachment was also wider and closer with time. Conclusion: Titanium surface coated with MS275/PLGA showed significantly higher cell proliferation and the more density of MS275 was dispersed on titanium discs, the faster cells grew.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.319-329
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• 2017

We investigated the host preference of Ricania app. at different developmental stages to select the effective control methods. Ricania spp. at different developmental stages preferred different host plants. During the nymphal period, individuals moved to the bottom due to environmental factors such as wind and rain, rather than inhabiting trees, and fed on various plants ranging from 1 year-old herbaceous plants to shrubs. Especially, at Palbong Mt. in Gonju, Ricania spp. nymphs preferred Symplocos chinensis f. pilosa, Celastrus orbiculatus, Euonymus alatus, Kalopanax septemlobus, Aralia elata, Styrax japonicas, Rubus parvifolius, Ru. coreanus, Ru. crataegifolius, Quercus acutissima, Cornus officinalis, Lespedeza bicolor, Albizia julibrissin, L. maximowiczii, Rhododendron schlippenbachii and Rh. indicum. At Yongbong Mt. in Hongseong, Ricania spp. adults preferred herbaceous plants, such as Helianthus annuus, Solanum nigrum, and Oenothera biennis rather than trees during the pre-oviposition stage. Subsequently, as the oviposition season began, Ricania spp. adults were rarely found in H. annuus, S. nigrum, or O. biennis and appeared to migrate to the perennial trees and shrubs hosts to lay eggs. At Palbong Mt., the main laying hosts of Ricania spp. adults were Weigela subsessilis, Ailanthus altissima, Q. aliena, Boehmeria platanifolia, Diospyros lotus, Ziziphus jujubae var. inermis, St. japonicus, Prunus mume, P. serrulata var. spontanea, Spiraea prunifolia f. simpliciflora, Ru. crataegifolius, Salix koreensis, Ru. yedoense f. poukhanense, and Co. controversa. The degree of egg laying, number of egg masses and adult Ricania spp. were significantly higher in sunlit areas than in shaded areas, in addition, the lower the altitude, the more adults were present. This study contributes toward the development of traps that can attract and control Ricania spp. and reduce the density of Ricania spp. that disturb the ecosystem.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.60-71
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• 2014

This study was conducted to identify the potential of rape stalk as a raw material for biorefinery process of rape flower. At first, rape stalk (RS) was immersed in distilled water (DW), acetic acid (AA), oxalic acid (OA), sulfuric acid (SA) and sodium hydroxide (SH) solutions, and the content of reducing sugars liberated from immersed RS was analyzed. Glucose, xylose, arabinose and sucrose were detected varying with the immersion type. In particular, 1% AA-immersion of RS for 72 hr was the most effective conditions to liberate glucose from RS. Secondly, the RS residues were used for elementary analysis and fabrication of fuel pellets. In addition to the solution type, concentration of immersion solutions (0%, 1%, 2%) and immersion time (24, 72, 120 hr) were used as experimental factors. The contents of nitrogen, sulfur and chlorine reduced effectively through the immersion of RS in DW, AA and OA solutions. For properties of RS-based pellets, bulk density and higher heating value of RS-based pellets greatly increased with the immersion of RS, and the qualities were much higher than those of the A-grade pellet of the EN standards. Ash content decreased remarkably through the immersion of RS, and was satisfied with the A-grade pellet standard. Durability was negatively affected by the immersion of RS, and did not reached to B-grade of the EN standard. In conclusion, acid immersion of RS can be a pretreatment method for the production of fuel pellet and bioethanol, but use of the immersed RS for the production of high-quality pellets might be restricted due to low durability of immersed-RS pellets. Therefore, further studies, such as investigation of detailed immersion conditions, fabrication of mixed pellets with wooden materials and addition of binders, are needed to resolve the problems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1439-1445
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• 2013

The aim of this study was to investigate the quality characteristics of rice cookies specifically prepared with rice flour following enzyme treatment. In this study, three types of specific enzyme treatments, that is, ${\alpha}$-amylase, ${\beta}$-amylase, and cellulose+${\beta}$-glucanase were applied on the effect of rice flour with respect to desired quality characteristics of the rice cookies. Based on our study results, we have found that the density of dough in the rice cookies was not significantly different between that of the non-enzyme treated (control) and the enzyme treated group. However, we found that the spread factor of rice cookies, prepared with rice flour treated with ${\beta}$-amylase, was higher than that of the control. It was also found that the moisture content of rice cookies (with added enzyme-treated rice flour) was 3.20 to 3.90%; however, this range is much lower than that observed in the control. Further, we observed that Hunter color's L-values were significantly higher for the control than those of the enzyme-treated cookies. We also found that hardness of enzyme-treated cookies was comparatively better than that of the control. In addition, the sensory acceptability scores of the enzyme-treated cookies were found to be significantly higher than the control in decisive parameters such as aroma, appearance, flavor, taste, texture, and overall acceptability. Based on our findings, we suggest that ${\alpha}$-amylase treated rice flour is an effective ingredient for improving the overall quality of rice cookies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1278-1285
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• 2017

Accumulation of excess low density lipoprotein (LDL) cholesterol in the blood can initiate and accelerate atherosclerosis. Statins mediate the transactivation of proprotein convertase subtilisin/kexin type 9 (PCSK9), which in turn limits their cholesterol-lowering effects via LDL receptor (LDLR) degradation. The objective of this study was to investigate whether or not Allium tuberosum (AT) regulates LDLR and PCSK9. Mice were fed a low fat control diet (LD) or Western diet (WD) supplemented with AT (1%, w/w). AT significantly attenuated total and LDL cholesterol levels in mice fed WD (P<0.05). AT also significantly inhibited hepatic PCSK9 gene expression (P<0.05) while AT maintained hepatic LDLR gene expression. To further investigate AT-mediated PCSK9 regulation, HepG2 cells were treated with 10% delipidated serum (DLPS) in the presence or absence of AT. Non-toxic level of AT dose-dependently increased the LDLR protein level, and AT at $400{\mu}g/mL$ markedly inhibited PCSK9 protein expression. Similarly, AT significantly increased LDLR gene expression, whereas it significantly down-regulated PCSK9 gene expression. AT-mediated reduction of PCSK9 gene expression is likely due to decreased hepatic nuclear factor $1{\alpha}$ ($HNF1{\alpha}$) expression, but not SREBP2 in HepG2 cells under lipid-depleted conditions. AT-mediated PCSK9 inhibition contributed to LDLR protein stabilization via protection against LDLR lysosomal degradation in HepG2 cells under lipid-depleted conditions. Further investigation is warranted to determine the active components of AT and whether or not these components are effective in reducing hypercholesterolemia.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.419-427
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• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.88-99
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• 2018

After UNESCO appointed Royal Tombs of the Joseon Dynasty to be World Cultural Heritages(2009), Cultural Heritage Administration in Korea established Management Office of Royal Tombs of the Joseon Dynasty(2012) and conducted Mid to Long-Term Plan on Conservation, Management, Utilization of World Heritage 'Royal Tombs of the Joseon Dynasty(2015)'. The report, as an implementation plan, provides detailed contents of the maintenance planning of Royal Tombs of the Joseon Dynasty. From this background, with a view to comprehending the characteristics of the maintenance planning of trees in historical landscape forests, this study extracted the contents related to the historical landscape forests of the 40 Royal Tombs of the Joseon Dynasty from the "Mid to Long-term Plan" and conducted literature research. The results of the study are as follows. First, from 2016, the short-term plans have provided detailed contents on logging, transplanting and planting trees in the plans divided by stages. On the other hand, the long-term plans, instead of presenting abstract contents repeatedly for each royal tomb, should seek vegetation landscape that each royal tomb should aim for. Second, since the areas that are in charge of the various functions of the royal tombs have been subjects to the maintenance planning, it is effective to establish a maintenance planning by separating functional areas instead of the comprehensive concept as historical landscape forests. Third, the maintenance planning of trees in historical landscape forest of the Royal Tombs of Joseon Dynasty is based on daily management such as density control and maintaining the shape of trees, which is necessary to sustain the forest. Also, due to the goal of preserving the pine forest, which is recognized as a prototype vegetation landscape, foreign species and other trees have been more cut down. With a few limited types of tall tree but few shrubs and flowers, it is characterized that the orientation toward aesthetic landscapes is insufficient in large green spaces. Fourth, according to the function of the tomb, it is divided into entrance area, ceremonial area, burial area and outer forest, and the contents of the maintenance planning are analyzed by basic conditions of tree management: prototype, ecology, functionality, and aesthetics. After studying the tree management characteristics of each area, four suggestions are made: understanding the diversity of trees that form prototype landscape as a management plan, sustainability of various forests adapted to ecological environment, convenience required in addition to ceremony and safety characterizing the Royal Tombs of Joseon Dynasty, and the necessity of access to aesthetic landscape on the tombs.