• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.2
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• pp.87-93
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• 1995

Strontium titanate single crystal was grown by floating wne method. Growth conditions are as follows; at air atmosphere, rotation rate of upper and lower shafts were 20 - 25 rpm, 15 - 20 rpm respectively and growth rate was 3 mmlhr. As grown crystal was light brown color and transparent. After annealing, color was faded away. Growth direction was [112] direction and it was confirmed that grown crystal has $SrTiO_3$single phase and stoichiometric composition by XRD and EDS. Etch pit pattern was investigated after chemical etching in $350^{\circ}C$, KOH solution for 5 min and dielectric constant was measured at the range of room temperature ~ $350^{\circ}C$ .

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.454-459
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• 1985

The structure of the seed of Lupinue angustifolius was studied in order to investigate the Food quality of lupin seed in comparision with soybean. The cotyledonary cells of lupinseed was in egg-like shape and much (more than 4 times) larger than those of soybean. The microstructure of cotyledonary cells of lupinseed was characterized with thick cell wall having distinct pit-pairs. The protein bodies in lupinseed cotyledon cell contained numerous crystaloids, which was absent in soybean. The middle lamella of soybean cell was partially disintegrated by excessive heat treatment ($120^{\circ}C$, 20 min), whereas those of lupinseed did not change much by heting at $120^{\circ}C$ for 130 min.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.569-574
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• 2008

Recently, the domestic remodeling market is increased in scale. This study is to develop the sanitary piping system which improves quality of life and facility performance when the aged public housing is remodeled. Above all, we found out three standard floor plans in bathrooms of the public housing. And then, the plan and section types of the sanitary piping system were developed for the on-floor piping, a construction cost of each section types was estimated to review the economical fact. Also, the field mock-up test was performed in the type of the pipe shaft with on-floor pit. In result, the developed sanitary piping system was available for the remodeling public housing without a great facility cost. Additionally, the sanitary pipe was replaced easily through the shaft and on-floor fit. And a noise was reduced to a lower unit when the water flowed down.

• Carbon letters
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• v.6 no.4
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• pp.227-233
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• 2005

Carbonization products C1, C2, C3, C4 and C5 were prepared by the carbonization of date pit in limited air, at 500, 600, 700, 800 and $1000^{\circ}C$, respectively. C1-V-600, C3-V-600, C1-V-1000 and C3-V-1000 were prepared by thermal treatment of C1 and C3 under vacuum at 600 and $1000^{\circ}C$. The textural properties were determined from nitrogen adsorption at 77 K and from carbon dioxide adsorption at 298 K. The surface pH, the FTIR spectra and the acid and base neutralization capacities of some carbons were investigated. The amounts of surface oxygen were determined by out-gassing the carbon-oxygen groups on the surface as $CO_2$ and CO. The adsorption of water vapor at 308 K on C1, C2, C3 and C4 was measured and the decomposition of $H_2O_2$ at 308 K was also investigated on C1, C2, C3, C4 and C5. The surface area and the total pore volume decreased with the rise of the carbonization temperature from 500 to $1000^{\circ}C$. The adsorption of water vapor is independent on the textural properties, while it is related to the amount of acidic carbon-oxygen groups on the surface. The catalytic activity of $H_2O_2$ decomposition does not depend on the textural properties, but directly related to the amount of basic carbon-oxygen complexes out-gassed as CO, at high temperatures.

• Journal of the Korean Academy of Pediatric Dentistry
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• v.33 no.2
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• pp.244-252
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• 2006

The aims of this study were to determine if flowable composites can be used as pit and fissure sealants without bonding agents. Three flowable composites(Filtek Flow, Tetric Flow, Charmfil Flow) and a filled sealant (Ultraseal XT plus) were used. The pattern of resin tag formation in the four sealant materials were compared using SEM. For the microleakage assessment, 54 extracted human premolar teeth were randomly divided into 3 groups containing 18 premolars each. In each group, a conventional filled sealant and one of the three flowable composites were applied to occlusal fissures. The teeth were thermocycled(1200 cycles between $5^{\circ}{\pm}2^{\circ}C\;and\;55^{\circ}{\pm}2^{\circ}C$ with a dwell time of 30 seconds) and immersed in a 1% methylene blue solution for 48 hours. Each tooth was sectioned and examined to determine the extent of dye penetration. Three flowable composites and a filed sealant showed a similar resin tag formation pattern. The three flowable composites showed significantly more microleakage in each group than the filled sealant. The level of microleakage was similar in the three flowable composites. Flowable composites are not recommended as pit and fissure sealants because more microleakage can occur even when occlural fissures are mechanically widened.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.393-400
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• 2006

In design of a deep geological repository for the high level wastes, it is very important that the temperature of the bentonite block should not be over $100^{\circ}C$ to maintain the integrity of the bentonite buffer block from the decay heat. In this study, for the layout of the repository to meet the requirement, the analysis of the disposal tunnel and disposal pit spacing was carried out. To do this, based on the reference repository concept, several cases of cooling times and disposal tunnel and disposal pit spacing were compared. The thermal stabilities of the disposal systems were analyzed in terms of the cooling time and spacing. The results showed that it was more desirable to determine the layout of the repository in terms of disposal pit spacing than the disposal tunnel spacing. The results of these analyses can be used in the deep geological repository design. The detailed analyses with the exact site characteristics data will reduce the uncertainty of the results.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.165-172
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• 1995

A transmission electron microscopic study was performed on the ultrastructure of the tegumental layer of GymophoLloines seoi (Digenea: Gymnophallidae) metacercarlae and adults. The metacercariae were obtained from naturally infected oysters, Crcssosoea gigas, and the adults from experimentally infected C3H mice. The tegumental layer generally revealed a small number of foldings, numerous small vacuoles, sines, and muscle bundles. Beneath the muscle layer, nuclei of the tegumental cells were located. There was little difference in the structure of the tegument between the metacercariae and adults. The oral sucker, having well-developed muscle layers, showed a similar structure to the ventral sucker except numerous foldlngs in the ventral sucker. The ventral pit was surrounded by a thin spcpiu layer, where a number of microtubules and mitochondria were seen. Around the ventral pit located well-developed circular and longitudinal muscles. The results showed that the ultrastructure of the tegumental layer of G. seoi metacercariae and adults revealed little difference from other trematodes in general. The ventral pit, a peculiar structure of this trematode, seems to function as a sphincter or an accessory adhesive organ.

• Progress in Superconductivity
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• v.3 no.2
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• pp.213-217
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• 2002

We have fabricated successfully single-filament composite $MgB_2$/SUS tapes, as an ultrarobust conductor type. The fabrication of the $MgB_2$/SUS tapes was performed by power-in-tube (PIT) process such as swaging and cold rolling. The critical transition temperatures $T_{c}$~38.5 K and ~36 K were observed for the sintered and the nonsintered $MgB_2$/SUS tapes, respectively In addition, the isothermal magnetization M(H) of the sintered $MgB_2$/SUS tapes was measured at temperatures T (between 5 and 50 K) in fields up to 6 T, employing a PPMS-9 (Quantum Design). The persistent current density (J$T_{P}$) values were obtained from the M(H) data, using Bean model, fur the sintered $MgB_2$/SUS tapes. The estimated values were higher than ~ 6$\times$ $10^{5}$ $A/\textrm{cm}^2$ at T = 5 K, with H : 0 G. We also investigated the cross section of the sintered tapes, by using SEM and EDX. An evidence of weak reaction on boundary between $MgB_2$ and SUS tube is found in the SEM and EDX.X.X.X.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.274-279
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• 2013

Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. During the FAC, a protective oxide layer on carbon steel dissolves into flowing water leading to a thinning of the oxide layer and accelerating corrosion of base material. As a result, severe failures may occur in the piping and equipment of NPPs. Effect of alloying elements on FAC of pipe materials was studied with rotating cylinder FAC test facility at $150^{\circ}C$ and at flow velocity of 4m/s. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO) and temperature. Test solution was the demineralized water, and DO concentration was less than 1 ppb. Surface appearance of A 106 Gr. B which is used widely in secondary pipe in NPPs showed orange peel appearance, typical appearance of FAC. The materials with Cr content higher than 0.17wt.% showed pit. The pit is thought to early degradation mode of FAC. The corrosion product within the pit was enriched with Cr, Mo, Cu, Ni and S. But S was not detected in SA336 F22V with 2.25wt.% Cr. The enrichment of Cr and Mo seemed to be related with low, solubility of Cr and Mo compared to Fe. Measured FAC rate was compared with Ducreaux's relationship and showed slightly lower FAC rate than Ducreaux's relationship.

• Journal of the Korean Geosynthetics Society
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• v.15 no.1
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• pp.59-70
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• 2016

The purpose of this study is to review that the VE techniques can be used as a selection tool of borrow pit locations. The analysis of the soil investigation report is performed for the selection of proposed borrow pit site on a large-scale residential development area. Possible earthwork volume of mining is estimated and the weighting matrix evaluation is applied to the VE techniques. After determining the evaluation items for VE assessment, important degree was calculated. The Rating and evaluation of performance is carried out on a proposed borrow pit site. And, development priority has to be decided for a proposed borrow pit sites. As a result, the relative construction cost is closely related to the haulage distance. As the haulage distance increases, the relative construction cost will be increased. Therefore, it was confirmed quantitatively that haulage distance has a significant impact on the select of borrow pits. Also, it was found that the condition of borrow pits itself is important, but it cannot be ignored the impact of the life cycle cost for the selection of optimal borrow pit sites.