목분의 첨가량에 가량에 따른 산화마그 산화마그네슘 경화체의 밀도 및 흡수율 특성

정병열 ( Byeong Yeol Jung ),김헌태 ( Heon Tae Kim ),이상수 ( Sang Soo Lee ),송하영 ( Ha Young Song ) 한국건축시공학회 2014 한국건축시공학회 학술발표대회 논문집 Vol.14 No.1

Recently, it changes to the frame construction in the wall type structure for the life span improvement of the apartment house of our country. The execution of the light panel increased while the execution of the frame construction increased. Therefore, the density and absorption ratio of the magnesium oxide matrix according to the wood flour amount of addition ratio property try to be analyze for the lightweight of the surface material of the light panel. The test result, the density has been declined as the addition ratio increase of the wood flour. In the case of the water absorption ratio, water absorption ratio has been increased as addition ratio increase of wood flour. However, wood flour addition ratio 15% determined the most appropriate when considering the density and water absorption ratio.

Sebum Absorption Characteristics of Polymer Microgel-containing Face Powder

Young Keun Lee,Fan-Long Jin,Soo-Jin Park* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.8

In this study, poly(iso-butyl methacrylate-co-ethylene glycol dimethacrylate) [poly(iso-BMA-co-EGDMA)] microgel was prepared and used as a face powder additive. The spreading, adhesiveness, and skin reactivity of poly(iso-BMA-co-EGDMA) microgel-containing face powder II were investigated and compared with the same properties of commercially available Silica bead 700-containing face powder I. In the results, the particle size of the poly(iso-BMA-co-EGDMA) microgel was significantly swelled as a result of sebum absorption. Face powder II showed a lower primary irritation index and a higher adhesiveness than did face powder I. Face powder I showed a low sebum absorption ratio and a relatively high rate of sebum absorption, whereas face powder II, contrastingly, exhibited a high sebum absorption ratio and a low rate of sebum absorption, which properties would reduce the phenomena of facial strain and sliminess. These results indicate that poly(iso-BMA-co-EGDMA) microgel has outstanding sebum absorption characteristic and adhesiveness, and thus that it is a good candidate for use as a face powder additive.

논문 : 인공풍화가속실험을 통한 울릉도에 분포하는 화산암의 풍화특성 고찰

우익 ( Ik Woo ) 대한지질공학회 2015 지질공학 Vol.25 No.4

이 연구에서는 울릉도에 분포하는 현무암질 각력암과 조면암, 화산각력암의 풍화특성을 울릉도의 기후조건을 고려하여 설계한 인공풍화가속실험을 이용하여 고찰하였다. 암석 시료는 XRF 결과를 이용하여 도시한 TAS diagram에 따라 화산암종류를 판별하고 XRD 분석으로 조성광물을 확인한 후, 시료를 일차적으로 구분하였으며, 이차적으로 흡수율에 의해 시료의 풍화정도에 따라 구분하였다. 인공풍화가속실험 결과, 흡수율 증가는 대부분의 시료에서 발생하였으나, 화산각력암을 제외한 대부분의 시료에서는 강도 저감이 발생하지 않았다. 특히, 조면암의 초기 흡수율이 크면 인공풍화가속실험에 따른 흡수율 증가률이 더욱 증대되었으며, 화산각력암은 기타 암석보다 높은 흡수율 증가와 점하중강도 감소를 보여주고 있다. 이러한 실험 결과로 조면암의 화학적 풍화속도가 시간에 따라 가속될 수 있다는 것을 예측할 수 있고, 화학 및 물리적 풍화에 대한 저항성이 약한 화산각력암은 짧은 시간에서도 감소가 발생할 수 있다는 것을 파악할 수 있었다. 따라서, 이러한 암석들이 분포하고 있는 일주도로에서는 낙석 및 산사태와 같은 자연재해에 대한 대책이 필요한 것으로 판단된다. Artificial accelerated weathering test evaluated rocks from near the circuit road of Ulleungdo island, approximately 120 km from east of the Korean Peninsula. The tests subjected rock specimens to conditions based on the climate of the island. The specimens (such as basaltic breccia, trachyte, volcanic breccia) were preliminarily classified using a TAS diagram (XRF data) and based on the constituent minerals (XRD data); they were further classified by weathering degree according to their absorption ratios. During the artificial accelerated weathering, the absorption ratio of most of the specimens increased, but the point-load strength did not decrease in most cases, except for the volcanic breccia. The greater initial absorption ratio of trachyte rock specimen in comparison withthe other specimens led to a greater increase of its absorption ratio during the artificial accelerated weathering test. The volcanic breccia specimens showed the greatest increase of absorption ratio and the biggest reduction ratio of the point- load strength during the tests. These results could aid prediction of the weathering rate of rocks in Ulleungdo island subjected to weathering processes; trachyte which appears to accelerate with time, and volcanic breccia whose mechanical strength can largely decrease in a relative short period of time. Proper measures therefore appear necessary for the prevention of natural disaster such as rock fall and landslide around the circuit road.

Sebum Absorption Characteristics of Polymer Microgel-containing Face Powder

Lee, Young-Keun,Jin, Fan-Long,Park, Soo-Jin Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.8

In this study, poly(iso-butyl methacrylate-co-ethylene glycol dimethacrylate) [poly(iso-BMA-co-EGDMA)] microgel was prepared and used as a face powder additive. The spreading, adhesiveness, and skin reactivity of poly(iso-BMA-co-EGDMA) microgel-containing face powder II were investigated and compared with the same properties of commercially available Silica bead 700-containing face powder I. In the results, the particle size of the poly(iso-BMA-co-EGDMA) microgel was significantly swelled as a result of sebum absorption. Face powder II showed a lower primary irritation index and a higher adhesiveness than did face powder I. Face powder I showed a low sebum absorption ratio and a relatively high rate of sebum absorption, whereas face powder II, contrastingly, exhibited a high sebum absorption ratio and a low rate of sebum absorption, which properties would reduce the phenomena of facial strain and sliminess. These results indicate that poly(iso- BMA-co-EGDMA) microgel has outstanding sebum absorption characteristic and adhesiveness, and thus that it is a good candidate for use as a face powder additive.

Simulation of $H_2O/LiBr$ Triple Effect Absorption Systems with a Modified Reverse Flow

Jo, Young-Kyong,Kim, Jin-Kyeong,Kang, Yang-Tae The Society of Air-Conditioning and Refrigerating 2007 International Journal Of Air-Conditioning and Refr Vol.15 No.3

In this study, a modified reverse flow type, one of the triple effect absorption cycles, is studied for performance improvement. The cycle simulation is carried out by using EES(Engineering Equation Solver) program for the working fluid of $H_2O/LiBr$ solution. The split-ratios of solution flow rate, UA of each component, pumping mass flow rate of solution are considered as key parameters. The results show that the optimal SRH (split ratio of high side) and SRL (split ratio of low side) values are 0.596 and 0.521, respectively. Under these conditions, the COP is maximized to 2.1. The optimal pumping mass flow rate is selected as 3 kg/s and the corresponding UAEV A is 121 kW/K in the present system. The present simulation results are compared to the other literature results from Kaita's (2002) and Cho's (1998) triple effect absorption systems. The present system has a lower solution temperature and a higher COP than the Kaita's modified reverse flow, and it also gives a higher COP than the Cho's parallel flow by adjusting split ratios.

Improvement in CO2 absorption and reduction of absorbent loss in aqueous NH3/triethanolamine/2-amino-2-methyl-1-propanol blends

오광중,강민경,전수빈,이민호 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6

Changes in the CO2 absorption rates and capacities of the absorbent 2-amino-2-methyl-1-propanol (AMP),blended with NH3 and other additives, were investigated toward performance improvement. The NH3-blended absorbent removed CO2 more efficiently than the AMP absorbent alone. However, absorbent loss through NH3 evaporation was observed under these conditions. A second absorbent, the tertiary amine triethanolamine (TEA), which has a low vapor pressure, was selected and blended with the NH3/AMP system to reduce NH3 evaporation. Its effects on NH3loss and the absorption rate and capacity of the NH3/AMP system were investigated, and the optimum blending ratios were determined. In addition, the absorbent blend at the optimum blending ratio was compared to AMP alone and the commercially available absorbent monoethanolamine at the same weight ratio. The thermal stabilities of the absorbents,under conditions used in the CO2 absorption process, were compared by thermogravimetric analysis.

누액방지형 하이드로젤형 흡습제의 제조와 특성 연구

이종인(Jong In Lee),윤재욱(Jaeuk Yoon),박수정(Sujeong Park),박인서(In Seo Park),박정욱(Jeong Uk Park),우인선(Insun Woo),차성경(Sung Kyung Cha),남병욱(Byeong Uk Nam),배진우(Jin Woo Bae) 한국고분자학회 2021 폴리머 Vol.45 No.4

해상무역의 발달로 다양한 제품들의 해상운송이 증가하고 있다. 수분에 민감한 제품들은 이 과정에서 많은 양의 습기에 노출되어 고장이 발생한다. 흡습제는 이러한 습기를 제거하기 위해 사용되며, 흡습제로 조해성 이온염을 많이 사용하고 있다. 하지만, 이들은 습기를 흡습하여 물을 형성하는데 이러한 물이 누액될 경우 제품의 부식을 일으켜 금전적인 손실을 초래한다. 본 연구에서는 수분을 흡습하면서도 누액 문제를 해결하기 위해서 조해성이 우수한 calcium chloride(CaCl₂) 또는 magnesium chloride(MgCl₂)의 이온염에 치환도가 서로 다른 carboxymethyl cellulose(CMC) 고분자를 도입하여 하이드로젤형 흡습제를 제조하였다. 하이드로젤형 흡습제는 물리적 가교를 통해서 이온염의 함량이 많을수록, 조해성이 우수할수록, CMC의 치환도가 낮을수록 더 높은 수분 흡습률을 보였지만, 점도는 감소되는 경향을 보였다. 또한 이러한 특성들은 이온염에 따라 변화하는 pH에 영향을 받은 것으로 알 수 있었다. Maritime transport of various products has been increased with developing seaborne trade. Moisture-sensitive products are exposed to a large amount of moisture during transport and broken down. Ionic salts having deliquescence often used as a desiccant for moisture removal. Although ionic salts produce water by moisture absorption, the leak of ionic salt-based aqueous solution seriously disrupts the products, resulting in financial loss. In this study, hydrogel-based desiccants showing simultaneous leak-proof and high moisture absorption ratio were prepared by calcium chloride (CaCl₂) or magnesium chloride (MgCl₂) exhibiting deliquescence with carboxymethyl cellulose (CMC) having different degree of substitution. Moisture absorption ratio of the hydrogel-based desiccants depended on the kind and the content of the deliquescent ionic salts and the substitution degree of CMC because they decide to make the physical crosslinking. However, viscosity of the hydrogel-based desiccants inversely decreased with increasing moisture absorption ratio. Also, pH changes depend on the sort of the deliquescent ionic salts and strongly affects the moisture absorption ratio and viscosity.

Effects of Silica Fume Content and Polymer-Binder Ratio on Properties of Ultrarapid-Hardening Polymer-Modified Mortars

최종윤,주명기,노병철 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.2

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapidhardeningpolymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrenebutadienerubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with varioussilica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonationdepth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardeningpolymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fumecontent. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume contentand polymer-binder ratio.

Effects of Silica Fume Content and Polymer-Binder Ratio on Properties of Ultrarapid-Hardening Polymer-Modified Mortars

Jong Yun Choi,Myung-Ki Joo,Byeong Cheol Lho 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.2

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapidhardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrenebutadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.

Effects of Silica Fume Content and Polymer-Binder Ratio on Properties of Ultrarapid-Hardening Polymer-Modified Mortars

Choi, Jong Yun,Joo, Myung-Ki,Lho, Byeong Cheol Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.2

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapid-hardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrene-butadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.