• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.99-106
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• 2011

In order to investigate rice stem proteome in response to heat stress, rice plants were subjected to heat treatment at 42$^{\circ}C$ and total soluble proteins were extracted from stem tissues, and were fractionated with 15% PEG (poly ethylene glycol) and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). After staining of 2-DE gels, 46 of differentially expressed proteins were extracted, digested by trypsin, and subjected to matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Proteins were identified through database search by using peptide mass fingerprints. Among them, 10 proteins were successfully identified. Seven proteins were up- and 3 proteins were down-regulated, respectively. These proteins are involved in energy and metabolism, redox homeostasis, and mitochondrial small heat shock proteins. The identification of some novel proteins in the heat stress response provides new insights that can lead to a better understanding of the molecular basis of heat-sensitivity in plants, and also useful to molecular breeding of thermotolerant forage crops.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.527-531
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• 2006

We have prepared organophilic inorganic particles and polyimide (PI) nanocomposite having excellent thermal stability and high dielectric constant that can be used for electronic application such as capacitor. We have chosen barium titanate (BT), a high dielectric constantmaterial and its surface was coated with nylon 6 to improve the affinity with PI. The FT-IR and TEM studies showed that the organophilic inorganic particle (BTN) has a polymer shell with thickness of 5 nm. We have suggested that it is possible to control the thickness of coating surface and also indicated the relationship between the ratio of inside and outside radius of BTN and the weight fraction of BT. The PI nanocomposite films based on poly(amic acid) and BTN were prepared by cyclodehydration reaction. The homogeneous dispersion of BTN in PI matrix was identified by using SEM. We have investigated the effect of BTN content on the coefficient of thermal stability, integral procedural decomposition temperature (IPDT), and dielectric constant of PI nanocomposite films.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1132-1141
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• 1996

Heterogeneous cation exchange membrane(HCEM) was prepared with LLDPE(Linear Low Density Poly-ethylene) as binder, powdered cation exchange resins($diameter{\leq}149{\mu}m$) as ion-exchange material and glycerol as additive for electrodialysis and electrodeionization system. The weight ratio of (binder/ion exchange)/glycerol was (60%/40%)/5%, (55%/45%)/5%, (50%/50%)/5% and (40%/60%)/5%. The characterization of prepared HCEM was evaluated on mechanical, electrochemical, morphology and ion permeable properties. It was compared with commercial membrane. Electrochemical properties of HCEM of (50%/50% )/5% were very similar to value of IONPURE(commercial membrane), in which ion exchange capacity, ion transfer number and membrane resistance were to be 1.733meq/g, 0.96 and $16.08{\Omega}/cm^2$, respectively. Ion permeability of the membrane was better than that of IONPURE membrane. Compared with IONPURE membrane, the HCEM had a higher tensile strength and lower elongation and modulus, in which HCEM had tensile strength of $62.33kg/cm^2$, elongation of 87.42% and modulus of $658.53kg/cm^2$. The HCEM of (50%/50% )15% was optimum combination.

• Spatial Information Research
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• v.14 no.1 s.36
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• pp.163-176
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• 2006

The concept of 'spatial association' explains spatial distribution pattern of geographical phenomenon based on similarity with neighborhoods, as in the Tobler's Law of Geography: 'Everything is related to everything else, but near things are more related than distant things.' In this study, we develop a time-series exploratory analysis tool for discovering temporal patterns of spatial association by combining spatial statistics and geo-visualization, and thus present a possibility to support spatial decision-making process. As for the spatial proximity weight matrix indispensable to measuring global and local spatial association, we employ a variety of flexible weighting schemes using geometric characteristics of areal unit. In addition, we renovate the existing visualization methods for more effective understanding of the procedures and results of time-series analysis on spatial association: for instance, temporal parallel coordinate plot with box plot, animated map for spatial association, and 3D Moran scatterplot. The feasibility of our system is verified by time-series analysis experiments on the spatial association of land price fluctuation rate for all administrative units in Korea, $1995{\sim}2004$.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.578-584
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• 2003

Polychlorinated biphenyls (PCBs) known as environmental contaminants in soil were analyzed by the soil pollution standard process test and the static supercritical $CO_2$ extraction mode. It was shown that the percent average recoveries of PCBs by the soil pollution standard process test were ranged in 25-35% and the corresponding standard deviations were above 10%. In contrast, the percent average recoveries of PCBs by the static supercritical $CO_2$ extraction mode were 2-2.5 times higher and standard deviations were within 7%. These results indicate that static supercritical $CO_2$ extraction mode may be a useful alternative to sample pretreatment certified by the soil pollution standard process test. The increasing supercritical $CO_2$ pressure from 1130 psi to 1996 psi at $40^{\circ}C$ enhanced the recovery of all PCB congeners from soil. However, at same Tc and Pc, the equilibrium time (5 versus 60 minutes) had no effect on the recovery of each PCB congener. Finally, similar PCB recoveries were obtained under the same extraction condition, regardless of the molecular weight and structure (coplanar versus non-coplanar) of PCB congeners.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.1-9
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• 2020

This study conducted to understand effects of CA (CaAl₂O₄) and CA₂ (CaAl₄O₇) ratio on chloride binding ability and compressive strength and pore structure of cement mortar incorporating mixture of CA and CA₂. The Portland cement based specimens were mixed with the clinkers CA and CA₂, and these calcium aluminate clinker mixture were replaced 0, 5, 10% by weight of cement. After all the test specimens were cured for 28 days under water curing, they were immersed in the distilled water and NaCl solution. As a result, 28 days compressive strength of all specimens was similar, and As the replacement ratio of calcium aluminate clinker in the specimen increased, Friedel's salt production tended to increase. However, it was dependent on the amount of Al₂O₃ in the level of 5% replacement and CA ratio in the level of 10% replacement. Through equilibrium isotherm result, it was also indicated that as replacement ratio of calcium aluminate clinker in cement matrix increased, chloride binding capacity was improved, and chloride penetration was suppressed. In this study, the specimen replaced with 10% of the calcium aluminate clinker mixture (CA 39%, CA₂ 60%) was remarkable to control chloride attack. We figured out necessity to understand optimal CA/CA₂ ratio to effectively apply CA₂ as a sustainable building material by improving the chloride binding ability in Portland cement based system.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.8
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• pp.36-44
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• 1999

This paper presents the design and fabrication of the duplexer for a Ka-band satellite transponder which is analyzed transmission characteristics by calculating the generalized scattering matrix using mode matching method. It is composed of 2 bandpass filters, coupled with H-plane T-junction having symmetrical inductive iris and E-plane metal insert structures. Compared with the size and weight of the Rx and Tx filter loaded with a transponders respectively, those of the duplexer can be effectively reduced. In a high power transmission, the variation of the filter characteristics is minimized by the scheme that irises are extended to the exterior of H-plane of the waveguide. This scheme needs no extra heat sinks for dissipating high power. The duplexer is designed to improve the simplification, durability and reliability by eliminating tuning screws, which have been used to compensate for the characteristics of fabricated filters. The bandpass filters of the duplexer show the insertion loss of less than 1.2 dB and the return loss in excess of 15 dB. The isolations of more than 65 dB have been achieved between Rx and Tx filter.

• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.977-987
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• 2013

This study aims to develop a multiple criteria decision making (MCDM) approach for flood vulnerability assessment which considers uncertainty. The flood vulnerability assessment procedure consists of three steps: (1) use the Delphi process to determine the criteria and their corresponding weights-the adopted criteria represent the social, economic, and environmental circumstances related to floods, (2) construct a fuzzy data matrix for the flood vulnerability criteria using fuzzification and standardization, and (3) set priorities based on the number of assessed vulnerabilities. This study uses a modified fuzzy TOPSIS method based on ${\alpha}$-level sets which considers various uncertainties related to weight derivation and crisp data aggregation. Further, Spearman's rank correlation analysis is used to compare the rankings obtained using the proposed method with those obtained using fuzzy TOPSIS with fuzzy data, TOPSIS, and WSM methods with crisp data. The fuzzy TOPSIS method based on ${\alpha}$-cut level sets is found to have a higher correlation rate than the other methods, and thus, it can reduce the difference of the rankings which uses crisp and fuzzy data. Thus, the proposed flood vulnerability assessment method can effectively support flood management policies.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.15-23
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• 2017

Objectives : It is well known that Sibjotang (Shizaotang), traditional herbal medicine formula, regulates the body fluid blood pressure homeostasis. This study is to investigate whether Sibjotang improves diabetic renal dysfunction in type II diabetes mellitus animal model, db/db mice. Methods : The animals model were divided into three groups at the age of 8 weeks; control group (C57BLKS/J-db/m mice), diabetic group [(C57BLKS/J+Lepr)-db/db mice], and Sibjotang group [(C57BLKS/J+Lepr)-db/db mice + Sibjotang 100 mg/kg/day]. During 8 weeks of treatment, blood glucose and urinary albumin excretion were checked in metabolic chamber at 8, 12, and 16 weeks of age, respectively. Results : Body weight and food intake of diabetic group were significantly higher than control group after 8 weeks administration. However, there were not significant different between the diabetic group and Sibjotang group. Urinary albumin excretion was significantly decreased in the Sibjotang group than the diabetic group. In addition, supplementation with Sibjotang significantly lowered levels of blood glucose, insulin, and homeostatic model assessment-insulin resistance (HOMA-IR), suggesting reduced insulin resistance. The ratio of mesangial matrix/glomerular area was markedly larger in diabetic group than control group, whereas Sibjotang significantly reduced this expansion. Moreover, immunohistological study revealed that Sibjotang attenuated the increase of transforming growth $factor(TGF)-{\beta}$ expression in kidney. Conclusion : Sibjotang ameliorates diabetes-associated renal injury through the improvement of the blood glucose and insulin sensitivity, and inhibiting the $TGF-{\beta}1$ expression. Therefore, Sibjotang may be a new therapeutic formula for the treatment of diabetic-associated renal dysfunction.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.265-273
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• 2000

Purpose : The aim of this study was to evaluate the bone mineral density of iliac and tibial bone which are frequently selected as autogenic bone graft donor sites, and to evaluate the efficiency of this method as a guideline for the selection of bone graft donor site. Materials and Methods : In this study 61 male and 70 female volunteers at Chungbuk National University Hospital were involved between Jan. 1998 to Sept. 1999. We measured bone mineral density of the iliac and the tibial bone using dual energy X-ray absorptiometry. We evaluated the data using the SAS system for Windows and bone mineral density of the lumbar was used for control. Results : Age showed the highest correlation in correlation matrix between physical and bone variables. Height and weight showed lower correlation of linear increment. In man, the change of bone density according to age demonstrated linear decrease irrespective of the lumbar, ilium, and tibia. In woman, the change of bone density according to age showed cubic form, which increased in the third and forth decade. So it had a peak bone mass on about 35 year-old, thereafter, the change of bone density slowly decreased until 50 year-old, but it rapidly decreased after 50 year-old and it slowly decreased again after 65 year-old. Both in all subjects and subject with osteoporosis, the change of bone mineral density according to age showed statistically significant decrease in lumbar and tibia, but ilium was irrespective. Conclusion : In patients of aged or with osteoporosis, ilium demonstrated less tendency of decrease in bone mineral density than tibia. So this preliminary study suggested that ilium seemed better donor site for autogenic bone graft than tibia.