• KIEAE Journal
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• v.17 no.3
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• pp.15-21
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• 2017

Purpose: "Building energy design standard" is used to limit the thermal transmittance of building in Korea. However, it only covers the insulation standard for each appropriate elements of a building, not the thermal performance of Junction thermal bridge of windows and doors installed in wall. Therefore in this study, we have evaluated the thermal performance of Junction thermal bridge depending on installation method and position of windows and provide it as design data. Method: We analyzed heat transfer of 4-Track sliding window and tilt & turn triple glazed window that are placed in the first class category on window energy efficiency rating using Window 7.4 and Therm 7.4. Result : First, linear thermal transmittance of 4-Track sliding window differs by 2.2 times or more depending of installation method and location. It is higher than the linear thermal transmittance, 0.01W/mK, proposed by Passivhaus. Second, linear thermal transmittance of Tilt & turn triple glazed window differs by 7.7 times or more depending of installation method and location. The average linear thermal transmittance was less than 0.01W /mK when windows were installed on the internal wall insulation by the fixed hardware attachment method. Third, the thermal losses of a window caused by a junction thermal bridge are inversely proportional to the window area and converge gradually as the area increased.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.429-435
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• 2003

The purpose of this study is to predict multiplication patterns of foodborne pathogens according to packaging methods and storage conditions in home-delivered meals. Pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok which inoculated $10^6\;CFU/g$ of foodborne pathogens were packaged by wrap packaging, top sealing, vacuum packaging and stored at 25, 4 and $-18^{\circ}C$ during 5 days. The result of study was revealed that the growth and multiplication pattern of the inoculated foodborne pathogens was inhibited in chilling and freezing storage after vacuum packaging, and was significantly influenced by storage temperature. The survival of Listeria monocytogenes was also significantly influenced by storage period. The effective method to preserve the bacteriologic safety of pan fried oak mushroom and meat and soy sauce glazed hair tail in home-delivered meals was stored for maximum three days in chilling storage after vacuum packaging.

• The Journal of Advanced Prosthodontics
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• v.11 no.3
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• pp.162-168
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• 2019

PURPOSE. The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel. MATERIALS AND METHODS. Twenty-five Y-TZP slabs from each brand (Lava, 3M and Bruxzir, Glidewell Laboratories) with different surface conditions (Control polished - CPZ; Polished/ground - GRZ; Polished/ground/repolished - RPZ; Glazed - GZ; Porcelain-veneered - PVZ; n=5) were abraded (500,000 cycles, 80 N) against artificial enamel (6 mm diameter steatite). Y-TZP roughness (in ${\mu}m$) before and after chewing simulation (CS) and antagonist steatite volume loss (in $mm^3$) were evaluated using a contact surface profilometer. Y-TZP roughness was analyzed by three-way analysis of variance (ANOVA) and steatite wear by two-way ANOVA and Tukey Honest Difference (HSD) (P=.05). RESULTS. There was no effect of Y-TZP brand on surface roughness (P=.216) and steatite loss (P=.064). A significant interaction effect (P<.001) between surface condition and CS on Y-TZP roughness was observed. GZ specimens showed higher roughness after CS (before CS - $3.7{\pm}1.8{\mu}m$; after CS - $13.54{\pm}3.11{\mu}m$), with partial removal of the glaze layer. Indenters abraded against CPZ ($0.09{\pm}0.03mm^3$) were worn more than those abraded against PVZ ($0.02{\pm}0.01mm^3$) and GZ ($0.02{\pm}0.01mm^3$). Higher wear caused by direct abrasion against zirconia was confirmed by SEM. CONCLUSION. Polishing with an intraoral polishing system did not reduce the roughness of zirconia. Wear of the opposing artificial enamel was affected by the material on the surface rather than the finishing technique applied, indicating that polished zirconia is more deleterious to artificial enamel than are glazed and porcelain-veneered restorations.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.195-209
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• 2003

The purpose of this study was to identify the hazard analysis critical control point on food production and transportation flow, applied to home-delivered meals for the elderly. To carry out this study, 1) pan-fried oak mushroom and meat, soy sauce glazed hair tail, and roasted dodok were selected as high nutrient and preferred foods for the elderly and 2) time, temperature, and microbiological quality(standard plate count, coliform, Salmonella spp, Vibrio parahaemolyticus, Staphylococcus spp., Escherichia coli O157:H7, and Listeria monocytogenes) were measured at various phases of the home-delivered meal production and its transportation flows. The results of this experiments are as follows: The temperature measured at cooling phases during the home-delivered meal production flows was 19.2 ∼ 20.0$^{\circ}C$ for the pan- fried oak mushroom and meat and the roasted dodok and was 24.0 ∼ 25.2$^{\circ}C$ for the soy sauce glazed hair tail. These temperature were in the potentially dangerous zone. Microbiological analysis showed that S. spp. was higher in the raw ingredients, including oak mushroom, hair tail, radish, and dodok, than the standard limit. SPC was lower than the standard limit from cooking to transportation phase, but SPC increased significantly during the cooling and packaging phase. The level of coliform detected was far lower than the standard limit and was not detected at all during the transportation phase. Few S. spp. was detected in the pan-fried oak mushroom and meat, but was found in above standards limit during the wrap packaging phase in the soy sauce glazed hair tail and roasted dodok. The level decreased rapidly during the holding and transportation phase. Sal. spp., V. parahaemolyticus, S. spp., E. coli O157:H7, and L. monocytogenes were not detected. For the pan-fried oak mushroom and meat, the critical control points were during the purchasing and receiving of raw ingredients, cooling, and packaging phases. For the soy sauce glazed hair tail and roasted dodok, the critical control points were during the purchasing and receiving of raw ingredients, preparation, cooling, and packaging phases.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.241-253
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• 2003

Changes in chemical, microbiological quality of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok in wrap packaging, top sealing, vacuum packaging were evaluated during storage 25$^{\circ}C$, 4$^{\circ}C$, -18$^{\circ}C$ for 5 days. The results were as follows: 1) The cases of chilled and frozen storage, there were small increases in the pH from the first day, with no differences between the different packaging methods, with the exception of the vacuum packaging, which was lower. The pH and Aw of the roasted dodok were lower than those of the other foods. The Aw for all three foods at room temperature significantly decreased in the wrap packaging and top sealing on day one, but the rate of reduction was lower when in chilled storage. The VBN increased with increasing length of storage, and temperatures, but the rate of increase was lower in the top sealing and vacuum packaging. The VBN of roasted dodok was considerably lower than with the other foods. The POV increased significantly on the first day or room temperature storage and the rate or increase was low in chilled End frozen storages, and in the vacuum packaging. 2) SPC of the roasted dodok at room temperature increased significantly within five days of storage. but was inhibited within five days in the vacuum packaging with chilled storage. The SPC of the soy sauce glazed hair tail was low in the top sealing and vacuum packaging when in chilled storage. The coliform of the pan fried oak mushroom and meat. on the fifth day of room temperature storage, was close to hazardous conditions for the wrap packaging. From the third day of chilled storage, few coliform were detected in the pan fried oak mushroom and meat, or the soy sauce glazed hair tail, but not in the vacuum packaging, within five days, for all three foods in frozen storage. The S. spp. had exceeded the standard in the wrap packaging and top sealing with the pan fried oak mushroom and meat on the third day at room temperature, but was not detected in the vacuum packaging within five days, and exceeded the standard in the wrap packaging on the fifth day of chilled storage. S. spp. was not detected in the soy sauce glazed hair tail within five days at all storage temperatures. S. spp. was not detected in the roasted dodok within five days of chilled and frozen storage, but was detected from the third day in the wrap packaging. and the fifth in the top sealing, at room temperature, which exceeded the standard. Sal. spp., V parahaemolyticus, E. coli O157:H7, L. monocytogenes were not detected. 3) The Aw was found to be influenced by storage temperature, period and packaging method, while the VBN was significantly influenced by the storage temperature and period. Regarding the SPC, the pan fried oak mushroom and meat was affected by the storage temperature and period, while the soy sauce glazed hair tail was influenced by the packaging method and storage period. The roasted dodok's microbiological quality was influenced by the method of packaging. The chemical, microbiological quality of home-delivered meals were preserved to be five days in the vacuum packaging, at. chilled and frozen storage.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.152-157
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• 2001

UTC(Unglazed Transpired Collector) system has recently emerged as a new solar air heating technology. It is relatively inexpensive because it has not a glazed material. And it demonstrates efficient particularly for the applications in which larger wall area facilities with a high outdoor air requirement. Mathematical algorithm for UTC thermal modeling has been understood for further improvement of the system. EES and TRNSYS model of actual solar wall panel could be developed for computer simulations under other conditions. Computer models could be validated with the measured data from fixed outdoor test cell in KIER(Korea Institute of Energy Research). Major design parameters could be identified such as panel configuration and absorptivity and emissivity values for UTC design.

• Journal of the Korean Ceramic Society
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• v.15 no.2
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• pp.66-71
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• 1978

The cobalt blue spinel stains (main composition; CoO:$Al_2O_3$=1 : 1) in CoO-NiO-$Al_2O_$3 and $CoO-Al_2O_3-Cr_2O_3$ system were prepared by the calcination of each component oxides to be adequate for the factory. The color development, the change of the lattice constnat of the spinel and its application to colored glazes were studied. The results were summarized as follows. 1) In CoO-Al_2O_3$ spinel, the excess addition of each component hardly made any variation in lattice constantand alumina-rich spinel specimens caused the brilliant blue color fade. 2) An increase of $Ni^{2+}$ in $CoO-NiO-Al_2O_3$ system, made the lattice constnat of the $CoO-Al_2O_3$ spinel smaller, and an increase of $Cr^{3+}$ in $CoO-Al_2O_3-Cr_2O_3$, larger. 3) Glazed stains under lead glaze were colored nearly same dark blue color fade.

• Journal of the Korean Ceramic Society
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• v.45 no.8
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• pp.453-458
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• 2008

New inorganic red pigments based on Cr-doped $Y_2O_3$ and $Al_2O_3$ were synthesized by solid state method and characterization of their pigments were characterized by using XRD, FT-IR, SEM and UV-Vis spectrophotometer. The single perovskite phase revealed at $1450^{\circ}C{\sim}1550^{\circ}C$ for 6 h due to using mineralizers. The color of pigment powders resulted out various red-shades depending on the compositions of used materials and temperatures. Glazed tiles painted with pigment powders showed red color in oxidation and reduction firing. The best red colour was obtained when the $Cr_2O_3$ was used 0.04 mole at $1450^{\circ}C$ for 6 h.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.57-66
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• 2011

A Photovoltaic/Thermal(PVT) solar system consists of PV module and thermal absorber plate which convert the absorbed solar radiation into electricity and heat. Meaningful researches and development (R&D) on the PVT technologies have been performed since the 1970s. This paper presents a review of the previous works covering the various types of PVT and their performance analysis in terms of electrical and thermal efficiency. This review compares electrical and thermal efficiency of the different types of PVT collectors and analyzes the parameters affecting PVT performance. Based on the literature review, box channel type PVT with unglazed, or flat plate PVT with glazed have the highest efficiency among them. From the literature review, R&D should be carried out aiming at improving their overall electrical and thermal efficiency, cutting down the cost, and making them more competitive in the energy consumption market.

• Journal of the Korean Ceramic Society
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• v.44 no.10
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• pp.554-561
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• 2007

Synthesis and characterization of pigments by using $Fe_2O_3,\;CoO,\;Cr_2O_3\;and\;MnO_2$ were undertaken. The resulting pigments were characterized by using XRD, SEM, FT-IR and UV-Vis spectrophotometer. The color of glazed tiles containing 6 wt% pigment changed from dark green to black depending on the compositions of used materials. Pigments were calcined with mixed materials at $1350^{\circ}C$, and the dark green and dark brown color were obtained. Pigments were used to determine possible interactions between a pigment and a glaze.