• 보존과학연구
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• s.30
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• pp.137-147
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• 2009

Mireuk temple site is located in Iksan, on the North Jeolla province in Korea, and confirmed tiles, potteries, metals, glasses and other materials that are remaining between Baekje Kingdom and Joseon period after excavations. It is also detected that production and supply of the materials in this era were started inside the country(domestic) at that time. This is important information for the understanding of the production and circulation systems. In this study, lead isotope ratios of 18 samples includedlead glass, crucibles and glazed rafter tiles excavated from Mireuk Temple Site of Baekje era were analyzed for the provenance study of raw glass material supply and distribution of glass products. The results of lead isotope ratio analysis have shown that all raw materials were located in the distribution area of Baekje region and also confirmed to be accord with the previous research results. As comparing the lead isotope ratios of glass and glass materials excavated from Mireuk Temple Site with Miyajidake tomb from Fukuoka Prefecture in Japan, it is found that the same raw materials were used for glass production. It means that there is the active connection between Mireuk temple site and Miyajidake and that these areas are sharing the same materials at the same period. It also shown that artifacts excavated from Miyajidake were strongly influenced from Baekje culture. And it is estimated that there is a possibility of the use ofsame materials whether the supplies of them are from a specific place of Baekje or not

• KIEAE Journal
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• v.11 no.3
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• pp.69-73
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• 2011

In general, there are two types of PVT module depending on the existence of the glass in front of PV module: glazed and unglazed. On the other hand, the water-type PVT modules can be classified into two types, according to absorber type: the sheet-and-tube absorber PVT module and the fully wetted absorber PVT module. The aim of this study is to analyze the electrical and thermal performance of a water-type PVT module with fully wetted absorber. For this study, a prototype of unglazed PVT module with fully wetted absorber was designed and built, and both the thermal and electrical performances of the prototype module were measured in outdoor conditions. A conventional mono-crystalline Si PV module was tested alongside the PVT module for their electrical performance comparison. The results showed that the thermal efficiency of the PVT module was average 51% and its electrical efficiency was average 14.3% in mean fluid temperature $10-40^{\circ}C$, whereas the electrical efficiency of the conventional PV module was average 12.6%. It is found that the electrical efficiency of the PVT module was improved by approximately 14% compared to that of the PV module. The temperature of PVT module becomes lower due to the cooling effect by the fluid of the absorber. The results proved that the electrical efficiency was higher when the mean fluid temperature was lower.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.121-126
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT) module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. In general, there are two different types of PVT module: glazed PVT module and unglazed PVT module. On the other hand, two types of the PVT module can be distinguished according to absorber on PV module rear side: the sheet-and-tube absorber PVT module and the fully wetted absorber PVT module. In this paper, the experimental performance of water type unglazed PVT with fully wetted absorber was analyzed. The electrical and thermal performance of the unglazed PVT were measured in outdoor conditions, and the results were analyzed. The experimental results showed that the thermal efficiency of the PVT module was 42% average, and its electrical efficiencies were 15.2% and 14.2% average, respectively, for the mean fluid temperature of $10-20^{\circ}C$ and $21-30^{\circ}C$. Thermal efficiency depends on solar radiation, mean fluid temperature and ambient temperature. The PVT module temperature is related to the cooling effect of the PV module by the fluid of the absorber. The results proved that the electrical efficiency was higher when the mean fluid temperature was lower.

• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.28-34
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• 2013

It is essential to reduce building energy consumption in office building because government enact policy which encourages building energy certification from 2013. Office building has high cooling energy demand due to large glazed area of facade in these days. Shading devices can be an alternative of reducing high cooling energy demand. So, this study simulated a variety of exterior venetian blinds to know how much building energy be affected by orientation and reflectance of slat. The results of this study are based on Seoul weather data. The following is a summary of this study. 1) As a slat of venetian blinds has the lower reflectance, the more building energy reduced. Reflectance is usually affected by color and material of slat. In case reflectance is 0.2 reduce 4% of building energy than reflectance is 0.8. 2) Horizontal exterior venetian blinds are more effective than vertical exterior venetian blinds in all of orientation. Horizontal shape is average 16% more effective in shading effect than vertical shape. 3) In this case study, the most effective shading device is low reflectance horizontal exterior venetian blinds that result about 18% building energy reduction than no shade model. The results of this research can be used to plan shading devices for energy conservative office building.

• Korean Journal of Materials Research
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• v.24 no.2
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• pp.73-80
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• 2014

Ink-jet printing technology has been widely attractive due to its facility for direct and fine printing on various substrates. Recent studies have focused on expanding the application of ink-jet printing technology from general consumer use and design companies to the prototype production of precision parts and parts manufacturing. The use of ink-jet printing technology in decorated tableware, tiles, and other ceramic products also has many advantages. The printing process is fast and can be adaptable to various kinds of objects because there is no direct contact point between the printer and the substrates to be printed. For application to ceramic product decoration, inks containing highly dispersed inorganic nano-pigments are required. Here we report the synthesis and characterization of blue $CoAl_2O_4$ nanopigment for ink-jet printing. Blue ceramic ink based on the obtained $CoAl_2O_4$ pigment was prepared by dissolving $CoAl_2O_4$ pigment in a mixed solution of ethylene glycol and ethanol with volume ratios of 7:3 and 8:2, respectively, to obtain the appropriate viscosity for ink-jet printing. The ink solution contained 15 wt% of $CoAl_2O_4$ pigment and Cetyltrimethyl ammonium bromide(CTAB) and Sodium dodecyl sulfate(SDS) as dispersive agents. The prepared blue ceramic ink was stably jetted and formed a sphere-shaped droplet from an ink-jet printer.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.93-98
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• 2011

A photovoltaic/thermal(PVT)collector produces both thermal energy and electricity simultaneously. The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A PVT module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat. In general, there are two different types of PVT module: glazed PVT module and unglazed PVT module. On the other hand, two types of the PVT module can be distinguished according to absorber on PV module rear side: the sheet-and-tube absorber PVT module and the fully wetted absorber PVT module. The absorber collector plays an important function in PVT system. It cools down the PV module, while collecting the thermal energy produced in the form of hot water. The aim of this study is to compare the electrical and thermal performance of two different PVT collectors, one with the rectangular tube and the other with fully wetted absorber PVT collectors. For this paper, the PVT collectors with two different types of thermal absorber were made, and both the thermal and electrical performance of them were measured in outdoor, and the results were compared. The experimental results were analyzed that the thermal efficiency of the fully wetted absorber PVT collector is about 8.7% higher than the sheet-and-tube absorber PVT collector, and for the electrical efficiency, the fully wetted absorber PVT collector had about 7% higher than the rectangular tube absorber.

• Fire Science and Engineering
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• v.23 no.5
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• pp.110-116
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• 2009

This study is related with fire risk assessment for fire and smoke spread of double skin facade system by use of FDS (Fire Dynamics Simulator) which is a computational fluid dynamics (CFD) model of fire-driven fluid flow. For the study, fire scenario is intended to evaluate the impact of a fire spread for glazed office building. The major purpose of this study is to analyze the fire risk depending on the width of between inner skin and outer skin and to present fire prevention method regarding double skin facade system. The result of analysis presents fire spread more vertically as intermediate space becomes narrow. It is anticipated that fire can spread upper 2 stories above the fire floor if intermediate space with not more than 1m width. Therefore, prevention of vertical fire spread is required.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.6
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• pp.997-1007
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• 2010

The purpose of this study was to examine the dietary attitudes, dish preferences, and plate waste status of elementary school students in Chungnam province. Questionnaires fearuring dietary attitudes, dish preferences, and plate waste measurements over 4 days were administered to 278 elementary school students (3~6th grades; boys 124, girls 154). Regarding plate waste of food, subjects showed the following in decreasing order: soup > vegetable > fish > kimchi > rice > meat. Regarding food preference, cooked rice showed the highest preference among rice dishes, whereas both boys and girls preferred stir-fried rice among one-dish meals. For soup, soup cooked with mear was highly preferred. However, soup with vegetables was preferred less. For meat, soy sauce-glazed chicken and bulgogi were the most preferred boys and girls. In addition, boys indicated a higher preference for most of the meat dishes than girls. Among the many types of kimchi, Chinese cabbage kimchi (Baechu Kimchi) was the most preferred. For the school meals, the served and consumed amounts by boys were higher than those of girls. However, there was no significant difference in plate waste between the boys and girls. To improve management of school meals, dietitians should understand factors that influence students' food preferences.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1456-1460
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• 2006

In order to determine the causes of sweetened adzuki ann spoilage, the characteristics of microorganism isolated from spoiled adzuki ann were investigated. The isolated microorganism was gram-positive, roil-shaped and shore-forming bacteria; its surface was smooth and glazed. From the results of the assimilation test of 46 different biochemicals by the Vitec 2 Compact test and comparison of the cellular wall composition of fatty acid by the data bank of Midi sherlock system, the microorganism was identified as Bacillus subtilis, D-value of the B. subtilis spore was 4.85 min at $115^{\circ}C$, 0.69 min at $121^{\circ}C$ and 0.48 min at $125^{\circ}C$; Z-value was 9.71. The Bacillus subtilis growth was not observed below water activity of 0.92 at $45^{\circ}C$. However, bacteria growth increased gradually as water activity increased above 0.93.

• The Journal of Advanced Prosthodontics
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• v.16 no.3
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• pp.174-188
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• 2024

PURPOSE. The purpose of this study was to investigate the effects of surface treatments, liquids, and aging on color, translucency, and surface properties of monolithic ceramics. MATERIALS AND METHODS. Lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) ceramics (n = 135 each) were cut and divided into three groups [crystallization+glaze (single stage), crystallization-glaze (two stages), and crystallization-polish (two stages)]. One sample from each group was examined using scanning electron microscopy (SEM). Remaining samples were divided into four subgroups (distilled water, coffee, grape juice, and smoothie) (n = 11 each), stored for 12 d in the respective liquids, and thermally aged. One sample from each subgroup was analyzed using SEM. The color, gloss, and roughness values of the samples were analyzed after surface treatment (initial) and storage under different liquids+aging conditions. The initial data and both the aged data and data change values were analyzed using robust two- and three-way analyses of variance. RESULTS. The glazed groups exhibited smoother surfaces. Ceramic type and ceramic-surface treatment interactions affected the initial translucency parameter (TP) (P < .001) and the initial and aged roughness values (P ≤ .001). Surface treatment type affected the color change (P < .001), and ceramic type affected the aged TP values (P < .001). Type of ceramic, surface treatment, and their interactions affected both the initial and aged gloss (P ≤ .001) and TP change values (P ≤ .015). Surface treatment type and ceramic-surface treatment interactions affected the gloss change values (P ≤ .001). CONCLUSION. Although both ceramics and all surface treatments are clinically applicable, crystallization-glaze is recommended. When gloss and smoothness are important or when translucency is important, ZLS or LDS may be preferred, respectively.