• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6439-6444
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• 2015

With increasing concern about global warming, CCS (Carbon dioxide capture and storage) has attracted much attention as a promising technology for reducing $CO_2$ emission. It is necessary to develop the cost-effective absorbents materials in order to rapid commercialize CCS technologies. In this work, he study for the promotion of absorption rate in $CO_2$ capture system using metal nanoparticle were investigated. Three kinds of metal nanoparticle, cobalt, zinc, and nickel, were prepared by wet and dry method and effect of preparation method on the absorption rate of $CO_2$ were compared. Among the tested using pH method, nickel nanoparticle prepared by wet method showed the most significant improvement of $CO_2$ absorption rate. In case that metal nanoparticle is applied to CCS process, it is expected to be more efficient in $CO_2$ capture process due to reduce the size of absorption tower.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.371-378
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• 2006

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete covered with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption, air permeability, carbonation, salt damage and chemical attack of concrete was improved remarkably by covering with it.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.67-75
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• 2006

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete spread with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption and air permeability of concrete was improved remarkably by spraying with it.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.86-86
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• 2019

일반적으로 하천에 설치하는 각종 이수 및 치수 시설물들은 각각의 고유기능을 충분히 발휘하도록 계획하고 설치하고 있으나, 이러한 하천 시설물 중에는 하천의 자연 환경에 부정적인 영향을 일으킬 수 있는 환경과 조화롭지 못한 시설물이 있기도 하다. 하도 만곡부에 설치하는 전통적인 수제, 즉 하안부에서 수로 중심방향으로 돌출하는 형식의 횡수제, 역시 외곽부 하안의 침식을 방지하기 위해 설치하는 시설물이지만 하천의 자연환경 측면에서는 바람직하지 못 한 현상을 일으키기도 한다. 본 연구에서 소개하는 잠형의 방틀공 수제는 하안부에 돌출하여 설치하는 기존 수제와 달리 만곡부 외측 하안에 근접하여 유수 방향으로 하상에 고정시키고 홍수 시에는 잠길 수 있는 높이로 방틀공을 설치하여 하천수의 흐름을 제어하는 시설물이다. 이와 같은 시설물은 만곡부에서 발생하는 2차류 흐름을 방지하고 유수의 수충력을 흡수 혹은 반사시킴으로써 하안부를 세굴로부터 보호할 뿐만 아니라 심각한 하상 세굴과 퇴적을 완화하는 하도의 안정 기능도 발휘하게 된다. 치수의 기능 외에도 하천 환경 측면에서는 수제의 안쪽에 형성되는 못 (pool)에 다양한 생물이 서식하는 서식기능을 담당하기도 한다. 본 고에서는 현재까지 국내에 설치한 사례가 없는 잠형 방틀형 수제의 효과를 검증하기 위해 강원도 양양 남대천에 구축하는 Test bed를 소개하고자 한다. 산지하천의 만곡부 하안부를 세굴로부터 보호하기 위해 설치하는 잠형 수제에 대한 Test bed 구축 배경과 설치 과정 등을 소개하여 이와 관련한 하천 기술자들에게 새로운 패러다임의 수제 설계가 이루어질 수 있는 계기를 제공하고자 한다.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.588-596
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• 1996

The optimum conditions of the 1st and 2nd distillation had been investigated to obtaine a high quality monomeric MDI and fire reactive polymeric MDI by purification of crude MDI. Effect of additives on the monomeric MDI's color change, dimerization and the reactivity of polymeric MDI with standard polyol system has been tested. When the monomeric MDI yield is approximately 32%, 4,4'-MDI content is above 98% in the monomeric MDI at the 1st distillation. When the separation ratio of initial portion and residue percentage, reflux ratio are set at respectively, approximately 20wt%, 9wt%, above 2 in order to minimize the content of 2,4'-MDI in monomeric MDI, the freezing point of final distilled monomeric MDI is above $38.4^{\circ}C$. Since the monomeric MDI is inherently unstable in the room condition, monomeric MDI easily changes it's color and conducts self-polymerization reaction. To increase the stability of monomeric MDI, the composition of antioxidant, which is composed of phenolic 1st antioxidant, phosphorus 2nd antioxidant, UV absorbent and Hindered amine light stabilizer are used, and benzoyl chloride as antipolymerization agent test are that APHA color is less than 20, dimer content is remained less than 0.36wt% after 45 days storage of monomeric MDI.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.157-164
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• 2015

Oleanolic acid is known as which anti-cancer, anti-sinhaeng angiogenic, anti-inflammatory, antioxidant and anti-wrinkle effects. We focused on the antioxidant activity of oleanolic acid was separated from the natural plant and It was confirmed that the whitening effect. In this study, oleanolic acid was stabilized by polyglyceryl surfactant which from natural origin with only a simple stirring operation, and compared with lecithin liposome that was manufactured with high cost facility. The transdermal transition rate of 0.4% oleanolic acid polyglyceryl nanoemulsion was 95%, and it was simillar with lecithin liposome of 92%. 65% of 3hr transdermal transition rate of polyglyceryl nanoemulsion indicate charistiristcs of quick release, compared with 45% of lecithin liposome's 3hr transdermal transition rate. In the in-vivo clinical trial test, polyglyceryl nanoemulsion of 0.4% oleanolic acid was higher 25% in 2nd week, 58% in 4th and 8th weeks than non-added oleanolic acid emulsion.

• Analytical Science and Technology
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• v.13 no.3
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• pp.282-290
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• 2000

In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-Vis spectroscopy, FT-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants (primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak $C_{18}$ column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt% by a quantitative analysis through UV spectroscopy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.482-487
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• 2016

Ultra-violet rays are very harmful to eye health care. The blocking of ultra-violet rays and a reduction of optical reflection in the visible light range, which is to increase the share of transmitted light, and avoid the formation of ghost images in imaging, are important for the applications of polymer eyeglasses lenses. In this study, the high-refractive index polymer lenses, n=1.67, were fabricated by injection-molded method with the xylene diisocyanate monomer, 2,3-bis-1-propanethiol monomer, and benzotriazol UV absorber (SEESORB 709) mixture. To reduce the reflection of the polymer lens surfaces, multi-layer anti-reflection (AR) coatings were coated for both sides of the polymer lens using an E-beam evaporation system. The optical properties of the UV blocking polymer lens were characterized using a UV-visible spectrometer. The material properties of the thin films, which were composed AR coating layers, refractive index, and surface roughness, were analyzed by ellipsometry and atomic force microscopy. As a result, the fabricated polymer lens perfectly blocked ultra-violet rays below 395 nm with a blocking rate greater than 99%.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.191-196
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• 2006

The injection of ozone, produced by dielectric barrier discharge, into the exhaust gas gives rise to a rapid oxidation of NO that is the main component of nitrogen oxides($NO_x$) in most practical exhaust gases. Once NO is converted into $NO_2$, it on readily be reduced to $N_2$ in the next step by a reducing agent such as sodium sulfide and sodium sulfite. The reducing agents used ca also remove $SO_2$ effectively, which makes it possible to treat $NO_x\;and\;SO_2$ simultaneously. The present two-step process made up of an ozonizing chamber and an absorber containing a reducing agent solution was able to remove about 95% of the $NO_x$ and 100% of the $SO_2$, initially contained in the simulated exhaust gas. The formation of $H_2S$ from sodium sulfide was prevented by using a strong basic reagent(NaOH) together with the reducing agent. The removal of $NO_x$\;and\;SO_2$ was more effective for $Na_2S$ than $Na_2SO_3$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.17-27
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• 2023

A study was performed to increase skin permeation of tocopheryl acetate, an oil-soluble component among tocopheryl acetate, salicylic acid, and niacinamide, which are the active ingredients of the anti-hair loss toner. As a method of transparently solubilizing tocopheryl acetate while containing salicyl acid and niacinamide, we used a swollen micelle structure that increased the size of the micelle formed by the aggregation of surfactants. The prepared swollen micelle solution contains three kinds of active ingredients, and poloxamer 407 and octyldodeceth-16 were used as surfactants to increase transparent properties and stability. In addition, isostearic acid was used as a co-surfactant to increase the size of micelles. To evaluate the physical properties of the prepared swollen micelles, turbidity at room temperature (25 ℃) was measured. The Franz diffusion cell method was used to evaluate the skin permeation rate of tocopheryl acetate among the hair-loss prevention components contained in swollen micelles. After 24 h, tocopheryl acetate showed a 6-fold improvement in skin permeation compared to the control group. Therefore, it can be seen that the swollen micelles developed in this study can be applied to hair-loss prevention products or solubilized formulations of various functional cosmetics.