• Korean Journal of Materials Research
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• v.1 no.1
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• pp.46-53
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• 1991

The stress of PSG (Phosphosilicate glass), USG (Undoped-silicate grass) and SiN films, which are mainly used as passivation layers in semiconductor memory devices, deposited by CVD methods has been studied as a function of film thickness and holding time in air. The stress of the PSG film or the USG film is increased in tensile state with increasing film thickness. On the other hand the stress level of the SiN film in compressive stress does not change as film thickness changes. The stress of PSG film shows the drastic change from the tensile stress to the compressive stress after the film is left 2 days in air. FTIR spectra indicated that the stress variation was due to the penetration of water molecule. It looks possible to recover the stress of about $2.5{\times}{10^9}dyne/cm^2$ by annealing treatment at $300^{\circ}C$ for 20min. The total stress of multi-layered films having the PSG film is determined mainly by the stress variation of PSG layer with holding time. The total stress of multi-layered film appears to have a functional relationship with the stress in the thickness of each film. The resistance against stress-migration of sputtered Al line increases with increasing the tensile stress for the PSG film or the USG film.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.50-54
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• 2002

The aim of this work to determine the formation of lactulose during heat treatment process as a contribution to the estabilishment of limits of chemical indicators for different types of heat processed milk and analyze of lactulose for the reconstituted milk added samples. The HTST(75$\^{C}$/15s) and UHT(130$\^{C}$/2∼3s) treatment realized with a pilot plant and heat-treated samples were stroed at 4, 10, 30$\^{C}$ for 4 weeks. Changes in lactulose was evaluated at 7 days intervals. The other heat treatment was sealed in glass tube and heated at 75$\^{C}$ for 10 to 120s and heated at 130$\^{C}$ for 2 to 60s in a thermostatically controlled constant temperature bath of glycerol. The reconstituted milk was made with full fat dry milk that reconstituted with deionized water to 10% total solid, and was added to milk at 10, 20, 30% respectively. The samples processed with a HTST pilot plant showed that lactulose was contained at 1.47∼1.52mg/10()ml and 8.19 ∼8.32mg/100ml for UHT-treated samples. Changes in the lactulose content of heat-treated samples during storage at 4 and 10$\^{C}$ for 4 weeks caused a slight increase, however a noticeable increase was observed at 30$\^{C}$ for 4 week. The glass tube samples showed that high correlations between relative increase in content of lactulose and increasing processing times(75$\^{C}$ : r = 0.986, 130$\^{C}$ : r = 0.987, respectively). Added with reconstituted milk would cause a increase of the lactulose content linear with increasing addition amount(r = 0.982). This results observed for lactulose in commercial milk samples would applied to the detection of chemical changes during heat treatment and illegal use of reconstituted milk.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.609-621
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• 1997

The purpose of this study was to evaluate the shear bond strength of three light-cured glass ionomer cements to blood contaminated bovine dentin. The materials used in this study were Fuji II LC, Dyract and Variglass VLC. The dentin conditioners were 10% polyacrylic acid, 10% maleic acid and 10% phosphoric acid. 180 lower anterior bovine teeth were selected in this study. The teeth were embedded in acrylic resin and were grounded with 320 to 600 grit silicon carbide paper to create a flat dentin surface. The teeth were divided into SIX groups. The experimental procedures in six groups were as follows; Group l(GF) : Samples bonded to dentin surface with Fuji II LC after 10% polyacrylic acid treatment. Group 2(BGF) : Samples bonded to dentin surface with Fuji II LC after 10% polyacrylic acid treatment and blood contamination. Group 3(MD) : Samples bonded to dentin surface with Dyract after 10% maleic acid treatment. Group 4(BMD) : Samples bonded to dentin surface with Dyract after 10% maleic acid treatment and blood contamination. Group 5(PV) : Samples bonded to dentin surface with Variglass VLC after 10% phosphoric acid treatment. Group 6(BPV) : Samples bonded-to dentin surface with Variglass VLC after 10% phosphoric acid treatment and blood contamination. Group 1,3 and 5 were classified into the control groups, while group 2,4 and 6 were classified into the experimental groups. Each group contained 30 samples. After 24 hours water storage at $37^{\circ}C$, all smples were subjected to a shear load to fracture at a cross head speed of 1.0 mm/min with Instron universal testing machine(No. 4467). Debonded surfaces were observed under Scanning Electron Microscope(Hitachi S-2300) at 20kvp. The data were evaluated statistically at the 95% confidence level with Student's t-test. The following results obtained; 1. Shear bond strengths were higher in the control groups(1,3,5 group) than in the experimental groups(2,4,6 group). 2. The shear bond strength of group 5(PV) was the highest in the control groups, and the group 5 was significantly higher than the group l(GF) on the shear bond strength. 3. The group 4(BMD) was the highest on the shear bond strength, and the group 2(BGF) was the lowest in the experimental groups. The group 4(BMD) and 6(BPV) showed a significant difference with the group 2 on the shear bond strength. 4. All the groups showed an adhesive-cohesive failure. except the group 2(BGF) showing adhesive failure.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.2
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• pp.54-60
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• 2018

The purpose of this study is to analyze the garden details of Carla Scarpa in order to understand his selection and composition of materials, detailing style and symbolism of the spaces. Literature review and a field trip were conducted for the study and the results are as follows. First, Scarpa used vernacular materials such as Murano glass and Istrian limestone, and juxtaposed various materials using contrast of color and texture. His mixed uses of traditional and modern materials shows the passage of time. Second, he create his own detail style such as ziggurat and geometric motif, which make the garden space to look more interesting and rich. Scarpa respected local craftsmanship like glass design and used textile design style such as overlaying. Third, symbolic uses of water features help make narrative and poetic gardens. Scarpa's unique detail style and respects for traditional craftsmanship provide lessons on how to interpretate traditional design style in modern garden.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2001.11a
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• pp.301-310
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• 2001

본 연구는 내화성능을 가진 수막보호유리벽을 실제 건축물에 적용하는데 있어서 필수적으로 고려해야 할 가상시나리오 중에서 수막이 유리면을 보호하기 이전에 유리면에 근접되어 있는 화염으로부터 방출되는 복사열이 유리면이 가열된 상태에서 수막이 형성될 경우 유리면의 온도가 급속히 냉각됨으로서 발생할 수 있는 급냉파열특성을 규명하기 위해 실험한 연구로서 가열면온도범위에 따라 유리면에$150^{\circ}C$이상 $250^{\circ}C$이하에서 수막이 형성될 경우 급냉파열은 일어나지 않았으나 일반유리는 $100^{\circ}C$이상 $150^{\circ}C$이하에서 급냉파열이 일어남을 확인하였다. 즉 방화구획벽에 적용가능한 수막형성유리벽의 유리가 강화유리인점을 착안하면 수막의 도포이전에 강화유리면의 온도가 $250^{\circ}C$까지 올라가기 전에는 수막을 유리면에 접촉하여도 유리면의 급냉파열이 일어나짐 않음을 확인할 수 있었다. 이점은 일정한 구획내에서 유리면의 직근에 설치된 감지기에 의해 수막형성시스템의 가동을 할 경우 급내파열형상이 발생하지 않는 온도범위를 설정할 때 중요한 데이터로 활용가능하다. 결과적으로 국부복사열에 의하여 온도범위를 설정할 때 중요한 데이터로 활용가능하다. 결과적으로 국부복사열에 의하여 유리면의 온도가 급냉파열현상을 일으키는 한계온도에 이르기 전에 유리벽체 상부의감지기의 작동이 필수적으로 일어날 수 있음을 증명한다면 수막을 이용한 유리벽체를 일정시간이상의 내화성능이 요구되는 방화구획의 수직부재로 활용하는데 있어서 걸림돌이 되는 급냉파열에 대한 우려를 종식시키는데 이바지할 수 있다.l류 11.56%, acid류 38.87%, hydrocarbon류 2.89%, ester류 0.80%, 총 70.32%가 확인되었다. Alcohol류에서 linalool가 3.78%, acid류에서는 caproic acid류가 14.40%, carbonyl류에서 2-hydroxy-4-methoxyacetophenone이 2.99%, hydrocabon류에서는 aromadendrene가1.59% 그리고 ester류에서는 methyl palmitate가 0.43%으로 가장 많이 함유하고 있었다.0ppm에서 약 25.6%흡수되었고 ferric citrate 100ppm은 24.7%, ferrous sulfate는 19.7%흡수되었다. ILC를 첨가하지 않은 100ppm 철분염 용액은 ferrous sulfate를 제외하고는 흡수도가 감소되었다. 철분 결핍된 쥐에게 gavage 방법에 의하여 철분강화우유를 투여하였을 때 철분 25ppm 시료에서는 ferrous sulfate가 12.5%로 가장 높았고 ferrous lactate는 8.1%, ferric citrate는 6.5% 흡수되었다. 철분 100ppm수준에서는 흡수율이 낮아져 ferrous sulfate는 25ppm 시료보다 절반이하 수준이었다. Ferric citrate는 차이가 거의 없었으며 ferrous lactate는 70%수준이었다. 이상의 결과에서 철분강화우유에 사용하기 적합한 철분염은 ferrous lactate, ferric citrate였는데 특히 ferrous lactate는 제품의 이화학적 품질, 생이용성 측면 모두에서 가장 좋은 것으로 나타났다.다 높았으며, 1회당 평균 8.1$\pm$5.1개의 난포란을 회수하였다.

• Resources Recycling
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• v.29 no.4
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• pp.15-30
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• 2020

Recently, it is increasing a amount of installed solar-cell rapidly, and end-of-life photovoltaic(ELP) modules are generated in according to the reduction of cell efficiency largely. Recycling of ELP modules are begun at an advanced nation already, but there are bring about environmental contamination and resource recovery problems owing to not treated ELP modules because of economic cost completely. First of all, there were researched basic study for treatment conditions of used solar cell inspection, dismantling of aluminum frame, crushing / grinding & separation of tempered glass, removal of back sheet & EVA film, leaching & precipitation recovery of valuable metals and treatment of waste water. Therefore, we establish optimum conditions through carried out of designed apparatus, installation of equipment, test operation & trouble shooting in scale of 1ton/day pilot plant test. Following to economic review, it does have the economic efficiency until to the case of tempered glass recovery, but does not have the economic value in case of total processes until to recover the valuable metals. However, there are guaranteed economic value if we are gained a large amount of the expenses through EPR supported system. It was confirmed the commercialized possibility of ELP modules recycling if there were established on the collecting ELP modules, reusing criteria, economical technology, enactment of directives and enforcement of EPR supported system efficiently.

• Journal of the Korean Geotechnical Society
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• v.25 no.5
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• pp.75-86
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• 2009

Salt, one of the most common soluble materials in engineering soil, may have an effect on mechanical behaviors of soils under its cementation process. In order to investigate this natural phenomenon, non-soluble material by using glass beads is mixed with salt electrolyte and cemented by using oven to evaporate water. Three different sizes of glass bead particles, 0.26, 0.5, and 1.29 mm, with different salt concentration, 0, 0.1, 0.2, 0.5, 1.0, and 2.0M, are explored by using P- and S-waves, excited by bender elements and piezo disk elemets, respectively. The velocities of the P-wave and S-wave of the particulate medium cemented by salt show three stages with the degree of saturation: 1) S-wave velocities increase while P-wave velocities reduce with degree of saturation changing from 100% to 90%; 2) Both velocities are stable with degree of saturation varying from 90% to 10%; 3) The velocities change enormously when the specimens are nearly dry with degree of saturation from 10% to 0%. Besides, the resonance frequencies of S-wave show similar stages to the S-wave velocities. This study demonstrates meaningful trends of elastic wave characteristics of geo-materials according to the cementation of dissolved salt.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.247-257
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• 2014

Assessment for operator's dermal and inhalation exposure to acetamiprid during cultivation of water melon in greenhouse was carried out. For dermal exposure measurement, whole body dosimetry (WBD) was performed as the first trial in Korea. WBD consists of cotton/polyester outer clothes and cotton inner clothes. Hand exposure was measured by washing of nitrile gloves and hands while head exposure was monitored by face/neck wipe technique. Inhalation exposure was monitored with personal air sampling pumps and IOM sampler (glass fiber filter). Analytical limit of quantitation was 2.5 ng/mL. Good reproducibility (C.V < 8.7%), linearity ($R^2$ > 0.99) and recovery (70~119%) were obtained. Field recovery of acetamiprid was 77~95%. During mixing/loading, hand exposure of acetamiprid was about 10 times ($229.7{\mu}g$) more than that of application case ($20.9{\mu}g$). During application, total dermal exposure was $1207.4{\mu}g$. Exposure of lower legs was $1132.1{\mu}g$, which is 93.8% of the total dermal exposure. Inhalation exposure during mixing/loading and application was not detected. Margin of safety (MOS) was calculated for risk assessment using male Korean average body weight (70 kg) and acceptable operator exposure level ($124{\mu}g/kg/day$) to give 140, suggesting that health risk of operator during treatment of acetamiprid for water melon in greenhouse could be safe.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.211-218
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• 2018

Instant face lifting cosmetics contain various film forming agents for stretching the wrinkles on the skin surface. But, most of the film-forming polymers have sticky feels. And they are easily scrubbed out when skin is rubbed on. In this study, we focused on the influence of sodium silicate that has rapid film forming effect on skin surface and immediate wrinkle reducing effect. Sodium silicate, also known as water glass or soluble glass, is a compound containing sodium oxide and silica. Sodium silicate is a white powder that is readily soluble in water, producing an alkaline solution. Sodium silicate is stable in neutral and alkaline solutions. The sodium silicate solution hardens by drying in air and rapidly forms a thin film. When the solution is applied to the skin, the fine membrane coating is formed by water evaporation and ionic bond re-formation. It also makes the strong siloxane (Si-O) bonding on the skin surface. When these fixation properties are applied to cosmetics, they can give remarkable skin tightening effect. The sodium silicate solution can provide the lifting effect by forming a film on skin at a proper concentration. But, skin irritation may be caused with too high concentration of sodium silicate. We studied a desirable range of the sodium silicate concentration and combination with other fixatives for skin care formulation that has no sticky feels and no scrubbing out phenomenon. Immediate lifting gel was developed by using sodium silicate and various thickening systems. Among of the various thickeners, aluminum magnesium silicate showed the best compatibility with sodium silicate for rapid lifting effect. This instant physical lifting gel was confirmed as a low stimulating formula by skin clinical test.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.158-166
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• 2014

This experiment has investigated suitable methods to improve precision water content monitoring of coconut coir substrates to control irrigation by frequency domain reflectometry(FDR) sensors. Specifically, water content changes and variations were observed at different sensing distances and positions from the irrigation dripper location, and different spaces between the FDR sensors with or without noise filters. Commercial coconut coir substrates containing different ratios of dust and chips(10:0, 7:3, 5:5, 3:7) were used. On the upper side and the side of the substrates, a FDR sensor was used at 5, 10, 20, 30cm distances respectively from the irrigation dripper point, and water content was measured by time after the irrigation. In the glass beads, sensors were installed with or without noise filtering. Closer sensing distance had a higher water content increasing rate, regardless of different coir substrate ratios. There were no differencies of water content increasing rates in 10:0 and 3:7 substrates between the upper side and the side. Whereas, 7:3 and 5:5 substrates showed higher increasing rates on the upper side measurements. Substrates with higher ratios of chip(3:7) had lower increasing rates than others. And, with noise filters, the exatitude of measurement was improved because the variation and deviation were reduced. Therefore, in coconut coir with FDR sensors, an efficient water content measurment to control irrigations can be achieved by installing sensors closer to an irrigation point and upper side of substrates with noise filters.