• Journal of the Korean Ceramic Society
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• v.29 no.11
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• pp.900-904
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• 1992

High temperature electrical conductivity was measured for perovskite La0.98Sr0.02MnO3 at 200~130$0^{\circ}C$ as a function of Po2 and 1/T. Perovskite La1-xSrxMnO3 system is the typical oxygen electrode in solid oxide fuel cell (SOFC). Acetate precursors were used for the preparation of mixed water solution and the calcined powders were reacted with Na2CO3 flux in order to obtain highly reactive powders of perovskite La0.98Sr0.02MnO3. The relative density was greatly increased above 90% because of the homogeneous sintering. From the conductivity ($\sigma$)-temperature and conductivity-Po2 at constant temperature, the defect structure of La0.98Sr0.02MnO3 was discussed. From the slope of 1n($\sigma$) vs 1/T, the activation energy of 0.069 and 0.108eV were evaluated for above 40$0^{\circ}C$, respectively. From the relationship between $\sigma$ and Po2, it was found that the decomposition of La0.98Sr0.02MnO3 was occurred at 10-15.5 atm(97$0^{\circ}C$) and 10-11 atm(125$0^{\circ}C$). It is supposed that the improvement of p-type conductivity may be leaded by the increase of Mn4+ concentration through the substitution of divalent/monovalent cations for La site in LaMnO3.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.929-934
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• 2001

This study aimed to examine the cause of latent hydraulic property manifestation of ground granulated blast-furnace slag(GGBFS) using different alkali activators in pH, type and quantity. According to the experimental result, the higher pH value accelerated lastly latent hydraulic property and the early stage strength of GCBFS was ranked as activators with the higher pH, in an order of NaOH, $Ca(OH)_{2}$ and $Na_{2}$$Co_{3}$. Also, NaOH had accelerated latent hydraulic property of GGBFS, which had 40~50% of the 3 and 7 days compressive strength of base mortar in case of using 10% of powder-weight. In the case of 30% of GGBFS substitution with annexing 2.5% $Ca(OH)_{2}$, the compressive strength on the 3 and 7 days of the early-age, was increased to 5~10% than that of the same admixture with no activator. With annexing 5.0% $Ca(OH)_{2}$, the strength was increased to 10~20%. Although activator NaOH was effective on the manifestation of latent hydraulic property, it caused cement mortar compressive strength decrease by enlarging pore diameter.

• The Korean Journal of Ceramics
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• v.1 no.1
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• pp.21-28
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• 1995

Electrical conductivity of $TiO_2$ thin films, deposited on $Al_2O_3$ substrates by metal organic chemical vapor deposition (MOCVD), was measured by four-point probe method in a temperature range from $800^{\circ}C$ to $1025^{\circ}C$ and an oxygen partial pressure range from $2.7{\times}10^{-5}$ atm to 1 atm. In the low oxygen partial pressure region n-type conduction was dominant, but in the high oxygen partial pressure region p-type conduction behavior appeared due to substitution of Ti ions by Al ions, which were diffused from the substrate during post deposition annealing process. Electrical conductivity of the film decreases in the n-type region and increases in the p-type region as the oxygen partial pressure increases. The transition points, which show the minimum conductivity, shifted to the higher oxygen partial pressure region as the measuring temperature increased, but it shifted to lower oxygen partial pressure region with an increase in the post annealing temperature. The results were also discussed with the possible defect models.

• Journal of the Korean Ceramic Society
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• v.50 no.2
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• pp.149-156
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• 2013

This study examines the effects of limestone's factors on the fluidity of cement paste when of up to 15%. As the substitution ratio of limestone powder increases, the fluidity of the paste is also improved; however, it has no correlation to the $CaCO_3$ content of the limestone, fineness of the limestone, and fluidity of the pastes. Regardless of clay content of the limestone, it showed a similar mini-slump, so there was no correlation between the clay content and the fluidity of the paste. Also, the total organic carbon content of the limestone and the fluidity of the paste showed no correlation. Regardless of the limestone's grade or fineness, n value of powder gained by using the Rosin-Rammler distribution function showed that the fluidity of the paste increased as the n value reduced. It was also shown that particle size distribution of ordinary Portland cement with limestone powder had a major effect on the fluidity of the paste.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1593-1600
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• 2014

Adsorption and desorption characteristics of the representative 10 kinds components consisting of gasoline vapor on activated carbon were investigated at the temperature range of $-30^{\circ}C{\sim}25^{\circ}C$. The breakthrough curves of each vapors obtained by the Thomas model were well described the breakthrough experimental results of this study. The breakthrough times of each vapors were correlated with the molecular weight, density, and vapor pressure. The breakthrough times had greater correlation with boiling point than molecular weight and density. The slope of the breakthrough curve was a proportional relationship with the rate constant (k) of Thomas model expression. The higher the slope of the breakthrough curve, the rate constant was larger. The biggest slope vapor had the smallest adsorption capacity ($q_e$). Adsorption and desorption characteristics of mixed vapor similar to the gasoline vapor were studied at room temperature ($25^{\circ}C$). The mixed vapor consisting of 9 components; group A (pentane, hexene, hexane), group B (benzene, toluene), group C (octane, ethylbenzene, xylene, nonane) was examined. Group A was not nearly adsorbed because of substitution by group C, and the desorption capacity of group A was smaller than group C. The adsorbed substances were confirmed to be Group C.

• Journal of the Korean Chemical Society
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• v.45 no.4
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• pp.334-340
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• 2001

The water soluble carboxymethyl-chitin (CM-chitin) has been well known to be very useful to the cosmetic field as a moisturizer, a smoothener, a cell activater and a cleaner for face skin conditioning. In this study, the preparation process of CM-chitin was simplified with elimination of some procedures in the conventional method. The chitin powder was mixed with sodium hydroxide solution. And then a mixture of sodium monochloroacetate (or monochloroacetic acid) and isopropyl alcohol (or a mixed solution with water and isopropyl alcohol) was added to thorough the agitation and the freezing during 16 hours. The CM-chitin with a high degree of substitution by the improved process was obtained.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.439-446
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• 2008

A fungicidal spray program for effective control of three major apple diseases in Korea (white rot, bitter rot, and Marssonina blotch) was developed. This was based on our previous studies showing that application of ergosterol biosynthesis inhibitors (EBIs) in early or mid-August can eradicate white rot infection in fruit and that some protective fungicides show after-infection activity against white rot. The basic spray program focused on control of white rot, the main target disease, and the fungicides were sprayed at 15-day intervals from petal fall to late August using fungicides that show after-infection and EBI activity. The basic spray program was modified over 4 successive years to improve control efficacy against bitter rot and Marssonina blotch, which sometimes cause as much damage as white rot. Modifications to the regime were made every year by replacing one fungicide in the basic program at a specific spraying time. Substitution of only one fungicide in the spray program, even early in the growing season, greatly influenced the final disease incidence at harvest. Applying this principle, a moderately efficient spray program for cv. Fuji that increased the spray interval from 10 to 15 days and thus reduced the number of sprays required per crop season was developed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.13-13
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• 2017

By the progress of genome sequencing, infrastructures for marker-assisted breeding (MAB) of rice came to be established. Fine mapping and gene isolation have been conducted using the breeding materials derived from natural variations and artificial mutants. Such genetic analysis by the genome-wide dense markers provided us the knowledge about the many genes controlling important traits. We identified several genes or quantitative trait loci (QTL) for heading date, blast resistance, eating quality, high-temperature stress tolerance, and so on. NILs of each gene controlling heading date contribute to elongate the rice harvest period. Determination of precise gene location of blast resistance gene pi21, allowed us to overcome linkage drag, co-introduction of undesirable eating quality. We could also breed the first practical rice cultivar in Japan with a brown planthopper resistance gene bph11 in the genetic back-ground of an elite cultivar. Discovery of major and minor QTLs for good eating quality allowed us to fine-tune of eating quality according to the rice planting area or usage of rice grain. Many rice cultivars have bred efficiently by MAB for several traits, or by marker-assisted backcross breeding through chromosome segment substitution lines (CSSLs) using genetically diverse accessions. We are also systematically supporting the crop breeding of other sectors by MAB or by providing resources such as CSSLs. It is possible to pyramid many genes for important traits by using MAB, but is still difficult to improve the yielding ability. We are performing a Genomic Selection (GS) for improvement of rice biomass and grain yield. We are also trying to apply the genome editing technology for high yield rice breeding.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.11-21
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• 1996

The first Mg-skarn minerals are found from magnetite ore deposits of the Janggun mine, Korea. The skarn minerals are composed of mostly chondrodite, olivine， chlorite, serpentine, phlogophite, talc, apatite, magnesite， dolomite, siderite and trace amount of clinopyroxene, amphibole, garnet, wollastonite associated with magnetite, pyrrhotite and pyrite. The skarn zone is developed in the magnetite deposits at the contact of the Mg-rich Janggun Limestone Formation and the Chunyang granite. The chondrodites are columnar and radial shapes and some of them show twins. The chemical compositions of twinning-type chondrodites have high FeO (4.63 to 5.6 wt%), MnO (0.26 to 0.46 wt%) and low MgO (55.02 to 56.18 wt%) relative to the radial-type chondrodites. Twinning in chondrodite has been formed in close relation to substitution between Mg and Fe + Mn in humite solid solution. Temperature, $-logfo_2$ and $X_{CO2}$ during the skarn stage of magnetite deposits from the Janggun mine range from 395 to $430^{\circ}C$, from 30.5 to 31.2 atm and from 0.06 to 0.09, respectively.

• Health Policy and Management
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• v.23 no.3
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• pp.210-223
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• 2013

Backgrounds: Escalating pharmaceutical expenditure has threatened the sustainability of National Health Insurance system in Korea. Generic medicines allow patients to access safe, effective, high-quality medicines at low cost, thus insurers could achieve significant financial savings by promotion of generics, if they are priced much lower than the originator. The purpose of this study was to review generic pricing as well as promotion policies in other countries and assess the implication of those policies. Methods: We reviewed the main measures adopted by the developed countries such as Austria, Belgium, Denmark, Finland, France, Germany, Italy, Japan, Netherlands, Norway, Sweden, United Kingdom, especially in countries where governments are the largest third-party payers or insurance finance resource is the national health insurance. Results: The foreign countries's experience with generic medicine policy shows that demand-side policies such as physician budgets, international nonproprietary name prescribing, generics substitution, patients co-payment as well as supply-side policies relating to pricing and reimbursement seems to play a critical role in developing the generic medicines market. Conclusion: Various strategy should be implemented to promote generic drug use.