• Journal of the Korean Recycled Construction Resources Institute
• /
• v.3 no.3
• /
• pp.228-236
• /
• 2015

In this research, the influence of painting materials and applying timing on carbonation and chloride resistances of high volume SCMs concrete was evaluated. As a durability improving method, comparative tests were conducted with painting materials of ERCO (emulsified refined cooking oil), RCO (refined cooking oil), WR (water repellent agent), and ERCO + WR and with painting timings of right after demolding, and 28 days after the wet curing. From the experiment results, in the case of carbonation and chloride resistance, the carbonation depth and chloride penetration depth were decreased when the painting materials were applied in 28 days of wet curing. Additionally, for painting materials, with the order of ERCO, RCO, ERCO+WR, and WR, the carbonation and chloride penentration was delayed. Hence it is considered that ERCO shows the most favorable performance of resistance against carbonation and chloride penetration.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2005.05a
• /
• pp.168-172
• /
• 2005

본 연구에서는 평판 디스플레이 Photo공정 중에서 무회전 도포(Spinless Coating)방식으로 기판(Glass)에 감광제 약액을 도포한 후 용매(Solvent)를 제거시키기 위한 진공건조장치(Vacuum dryer)에서 감광제 도포막의 품질에 영향을 주지 않는 범위 안에서의 용매 제거시간을 단축하기 위한 진공챔버의 용적에 따른 진공포트의 크기 및 배치에 대한 최적화를 구현하였다. 구현된 챔버의 용적과 진공포트의 크기 및 배치를 바탕으로 진공건조장치를 챔버, 챔버 구동부, 기판 구동부, 진공펌프, 그리고 $N_2$ 공급부로 모듈화하여 구성하였으며. 실제 도포 기판을 이용하여 진공건조를 실시한 후 도포막을 검사함으로써 진공포트에 대한 최적화를 검증함과 동시에 진공건조 능력을 확인하였다.

• Korean Journal of Materials Research
• /
• v.3 no.4
• /
• pp.372-380
• /
• 1993

In order to improve the oxidative resistance of carbon/carbon composites, aluminium-isopropoxide and aluminium-tri-sec-butoxide sol were coated on the surface of 2D--carbon/carbon composiles and the effects uf coating were investigated. The effects of oxidative resistance were dominant in the case of catalyst/alkoxide mole ratio, 0.07, and $H_2O$/alkoxide mole ratio, 100. Through the dynamic TGA analysis with the heating rate of 20%/min, oxidative initiation tempera~ ture was enhanced about $80^{\circ}C$. The oxidative resistance effects of alkoxide sol were improved according to the times of coating. Also the 20% weight loss time of coated samples by TGA analysis was 20% better than that of un~ coated samples. The thickness of 1^{st} coated layer was about 3${\mu}$m and that of $2^{nd}$ and $3^{nd}$ coated layers was about respectively 4~5${\mu}$m and the weight loss were increased with the increasing of thermal shock test times.

• Membrane Journal
• /
• v.18 no.3
• /
• pp.198-205
• /
• 2008

A novel technology for homogeneous deposition of zeolite particles on a porous support was developed so that those particles played a seeding role for the growth of zeolite crystals. After the particles were dispersed in water, the aqueous solution was 134 through the bore of a porous tubular support. By keeping the other side of the support in a vacuum, the aqueous solution passed through the pores of the support, leading the particles to be homogeneously deposited on the support. The amount of the deposited particles was investigated by changing the following operating parameters: a particle concentration in the solution, a time for deposition, and the feeding rate of the solution. The amount of the deposited particles increased from 0.0019 g to 0.0208 g as the concentration of the particles was changed from 0.01 wt% to 0.3 wt%, while the feeding rate and the deposition time were kept to 100 mL/min and 4 min, respectively. As the deposition time was varied from 1 min to 4 min, the deposition amount increased from 0.0004g to 0.0019g at the typical condition of the rest parameters. Also, it was observed that the deposited weight increased from 0.0029 g to 0.01 g as the feeding rate increased from 100 mL/min to 300 mL/min. However, the total permeance of water and ethanol decreased through the zeolite membrane as the deposited weight increased.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.8
• /
• pp.1010-1015
• /
• 2006

p-Pheylenediamimine (PPD) is one of hair dye's ingredients, and the mixture of PPD with hydrogen peroxide is generally used to dye hair at beauty shop. This study is conducted to investigate the effect of oxidized PPD on rat skin. 6% hydrogen peroxide, PPD (5% PPD in 2% $NH_4OH$) or the mixture (isovolumed mixture of 5% PPD and 6% hydrogen peroxide in 2% $NH_4OH$) was applied to rat skin ($25\;mg/16.5\;cm^2$) five times every other day. The activity of acid phosphatase (ACP) was more increased in the mixture of PPD with hydrogen peroxide applied group than PPD applied group. Furthermore, the activity of glucose 6-phosphatase (G6Pase) in the mixture of PPD with hydrogen peroxide applied group showed higher decreasing rate than that of PPD applied group. In histopathological findings, the mixed PPD with hydrogen peroxide applied group showed more thickening of epithelium, increased numbers of dermal fibroblasts, and the dilatation of dermal capillaries than PPD applied group. The significant increasing of xanthine oxidase (XO) activity was determined in mixture of PPD with hydrogen peroxide applied group compared with PPD applied group. However, reactive oxygen species (ROS) scavenging system, the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) were more significantly decreased in mixed PPD with hydrogen peroxide applied groups than in PPD applied group. In conclusion, topical application with the mixture of PPD with hydrogen peroxide compared with PPD application resulted in imbalance with ROS generating and scavenging which probably led to severe skin injury.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.5
• /
• pp.568-572
• /
• 1999

Coating with chitosan ($2\%$, pH: 5.0) had a beneficial effect such as less weight loss, flesh firmness and maintenance of sugar content of tomatoes stored at the normal temperature. The weight loss of chitosan-coated tomatoes was $4.8\%$ during the storage-period (18days) while that of control was $10.2\%$. When it was stored for 18 days, the tomatoes coated with chitosan showed higher in firmness (1.63 kg) and pectin content ($0,58g\%$) than the control (1.03 kg, $0.44g\%$). For the total soluble acid and pH, the tomatoes coated with chitosan were higher in oxalic acid ($0.17 g\%$) than the control ($0.15 g\%$) and the latter were higher in the pH than the former, when they were stored for 18 days.

• The korean journal of orthodontics
• /
• v.3 no.1
• /
• pp.21-28
• /
• 1972

저자는 direct bonding system의 pretreatment액 처리후 Epoxy adhesive의 bonding strength의 변화를 측정하기 위해서 발거된 상악 전치 진면 법랑질 표면에 pretreatment액으로서 $65\%$ phosphoric acid를 도포한 실험군과 도포하지 않은 비교군을 비교연구하고 임상에 적용하여 다음과 같은 결과를 얻었다. 1. 법랑질 표면에 pumicing과 $65\%$ phosphoric acid를 도포했을때 joint strength는 현저히 상승했다. 2. Epoxy adhesive의 bonding strength는 plastic attachment를 치아면에 접착유지시키기에 충분하며 임상적으로 이용할 수 있다. 3. Joint area가 클 수록 bonding strength는 증가했다.

• Journal of Convergence for Information Technology
• /
• v.11 no.2
• /
• pp.188-193
• /
• 2021

In this study, the moisture content of the face skin was changed according to the number of skin applications for female college students under 25 years of age. Moisture contents were measured using a skin moisture meter (skin oil and moisture meter, PRC, China). Skin used 500ml of Innisfree's blueberry rebalancing skin as a clinical trial material. Both the forehead, eyes, cheeks, and chin had a higher moisture content after one layer of application than before and after one layer of application, and after ten layers of application, it can be seen that the moisture content is higher. As a result, when applying basic products after washing your face, the first step is to increase the number of skins, and then apply basic products such as lotion and moisturizing cream to increase the moisture content.

• Composites Research
• /
• v.37 no.2
• /
• pp.126-131
• /
• 2024

The moisture absorption rate and structural strength changes of oven-cured composite skin based on closed molds were studied. Moisture absorption was performed on specimens with and without filler applied. The specimens were exposed to moisture for up to 231 days. Tensile and compression tests were conducted with and without filler application. As a result of the test, the moisture absorption rates of the tensile and compressive specimens without filler were 2.4 and 0.3% higher, respectively, than those with the filler applied. The tensile and compressive strengths of the specimen without filler applied were average 305 MPa and 139 MPa, respectively, and the tensile and compressive strengths of the specimen with filler applied were 313 MPa and 166 MPa, respectively, appeared high.

• Journal of Bio-Environment Control
• /
• v.25 no.4
• /
• pp.249-254
• /
• 2016

This study was carried out to evaluate the efficiency of white shading agent for reduction of greenhouse air temperature and to develop cost-effective cooling strategies for strawberry seedling production during hot seasons. Experiment results showed that solar radiation ($W/m^2$) was reduced by 14~17% and 33~37% for 15% and 35% white wash shading treatments, respectively, in black shading net treatment solar radiation was reduced by 39~44% compared to non-shaded treatment. Measured greenhouse air temperatures in 15% and 35% white wash shading treatments were $38.4^{\circ}C$ and $36.5^{\circ}C$, respectively, whereas in black shading net covered greenhouses air temperature was $35.1^{\circ}C$, thereby 35% and 15% shading treatments showed 3.3 and $1.9^{\circ}C$ higher air temperatures than black net shading treatment. Crown diameter of strawberry plants in black net shading treatment was 7.5mm, and in 15% and 35% white wash shading treatments were 8.6mm and 8.3mm, respectively. Strawberry transplants grown in 35% white wash shading treatment produced the highest above ground fresh weight(7.8g), followed by 15% white wash shading(6.7g) and black net shading treatments(5.8g). Also, both 15% and 35% white wash shading treatments produced higher root fresh weight(4.1g and 4.3g) compare to black net shading treatments(2.7g).