• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.374-384
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• 1979

Hydration scheme and hydration energy are determined in ${\alpha}$ cage of zeolite NaA. The selectivity between Na(1) and Na(2) is determined from energy calculation. The waters in ${\alpha}$ cage form a distorted dodecahedral cage. The average binding energies of water(1), water(2) and water(3) are -29.847, -25.344 and -15.888 kcal/mole respectively. The positions of oxygens of hydrated waters are in good agreement with the X-ray data. The heat of immersion curve is also obtained. This result is in good agreement with the differential heat of sorption curve obtained from differential thermal analysis. It is concluded that theoretical method provides considerable uses in the determination and understanding of the hydration and interaction energy of zeolites sorbate binding.

• Polymer(Korea)
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• v.31 no.4
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• pp.349-355
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• 2007

Poly(N-isopropylacrylamide-co-acrylonitrile) [P(NIPAAm-co-AN)] copolymers with AN content of up to 10 mol% and their hydrogels were synthesized using water as a reaction medium, and the effects of AN unit incorporation on the critical gel transition temperature(CGTT) and swelling behaviors of the hydrogels were investigated. The CGTT of the copolymer hydrogel was $30{\sim}32\;^{\circ}C$, decreasing with increasing AN content. Below CGTT, swelling rate and equilibrium swelling ratio of the copolymer hydrogel decreased with increasing AN content. On the other hand, it exhibited faster deswelling and lower equilibrium deswelling ratio with increasing AN content above CGTT.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.198-204
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• 2005

Fluosilicate salts based hydration heat reducer(SWP-HR), used in this study, is composed of fluosilicate salts, soluble silica, aromatic polymer condensate and nitrate salt based inorganic compound with latent heat property. Effects of SWP-HR addition on the hydration heat and anti-crack property of cement mortar were investigated. Adiabatic hydration temperature and drying shrinkage length of SWP-HR added cement mortar had a tendency to decrease compared to those of cement mortar without SWP-HR addition. Also, it was confirmed through crack pattern experiment of plate-form specimen for elucidating crack-reducing characteristic that anti-crack property of SWP-HR added cement mortar was improved.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.611-625
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• 2021

Mg crowns were manufactured using domestic dolomite (Ca·Mg(CO₃)₂) (20~30 mm). In order to manufacture the calcined dolomite (CaO·MgO), (a) electric furnace (950 ℃, 480 min) and (b) microwave furnace (950 ℃, 60 min) processes were used. As a result of XRD analysis, it was analyzed as (a) CaO 56.9 wt%, MgO 43.1 wt% by electric furnace process and (b) CaO 55 wt%, MgO 45 wt% by microwave furnace process. Even when the decarbonation reaction time of dolomite was shortened by 1/8 in microwave furnace process compare with electric furnace process, the calcined dolomite could be produced. The hydration reaction (ASTM C 110) is a standard for the hydration reactivity of calcined dolomite, and the calcined dolomite produced by electric furnace process showed a high hydration reactivity (max temp 79.8 ℃/1.5 minutes). Such hydration reactivity was occurred by only CaO hydration reaction and that was confirmed by XRD analysis. The calcined dolomite produced by microwave furnace process showed low hydration reactivity (max temp 81.7 ℃/19.5 minutes). Such low hydration reactivity was occurred by CaO and MgO hydration reaction due to the hydration reaction of CaO thereafter occurring of the hydration reaction of MgO, and that was confirmed by XRD analysis. The prepared Mg crown were 58.8 g and 74.6 g by electric furnace and microwave furnace processes, respectively, under the reaction conditions of 1,230 ℃, 60 min, 5 × 10^-2 torr by silicothermic reduction.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.661-668
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• 2008

It is necessary to develop a new technology for effectively reducing hydration heat and controlling thermal cracking caused increasing construction of large size massive concrete structures such as mat foundation of high-rise building, grandiose bridge, and LNG tank. Therefor, to develop a new technology for reducing hydration heat of large size massive concrete in this study, after developing the latent heat binder for controling hydration heat of concrete by application of latent heat material, it was investigated basic properties and durability such as slump, air content and compressive strength, shrinkage properties, permeability, freezing and thawing resistance, corrosion, and hydration heat generation properties of concrete using latent heat binder. As a test result, it was confirmed that latent heat binder was not affected adversely the basic property and durability of concrete, and was advanced on the reduction of hydration heat and control of thermal crack. It is expected to be applied as the excellent technology on the management of hydration heat and thermal crack in large size mass concrete structures.

• Polymer(Korea)
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• v.33 no.5
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• pp.441-445
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• 2009

In order to develop an intelligent delivery system for cosmetic active agents (e.g., arbutin, ascorbic acid, and adenosine), pH-responsive P(MAA-co-PEGMA) hydrogel particles having an average size of approx. $2{\mu}m$ and spherical shape were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P (MAA-co-PEGMA) hydro gels at a pH 5, which is the $pK_a$ of the hydrogel. To determine the factors that have an effect on the loading of cosmetic active agents into the hydrogel, the loading efficiency of the active agents was investigated at various MAA and EG compositions of the hydrogel and the loading pH conditions. When the MAA contents in the hydrogel decreased, the loading efficiency of the active agents increased. In loading experiments with different pH conditions, the active agents showed higher loading efficiency into the hydrogel at the pH where the hydrogel was at the swollen state than at the pH where the electrostatic repulsion was minimized.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1019-1022
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• 2015

사회적 약자인 청각장애인들의 수화통역 서비스가 대체로 만족스럽게 제공되고 있지 않다. 또한 청각 장애인수 대비 수화통역가의 부족과 일반인과의 즉각적인 소통이 어려워 일상생활에 불편함을 느끼는 청각장애인들이 많다. 이의 문제점을 착안하여 본 연구에서는 청각장애인들이 휴대할 수 있는 수화 통역기를 개발하고자 한다. 청각장애인들의 손동작을 인식할 수 있는 3D센서 립모션(Leap-Motion)을 통해 수화를 인식한다. 립모션 센서와 안드로이드 스마트폰 및 태블릿과 연결하여 손 데이터 값을 분석했다. 분석한 손 데이터 값과 특정 지화(자음, 모음)와 간단한 인사말의 수화동작을 취할 때, 트래킹되는 데이터 값을 비교하여 수화를 인식하고 수화와 인식된 지화의 자음과 모음을 글자로 완성시켜, 텍스트와 음성으로 출력한다. 또한 립모션이 부착된 하드케이스 안에 스마트기기 탈착이 가능한 실용성 있는 수화통역기 제품 개발에 대한 연구를 목표로 하고 있다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.154-155
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• 2001

난백과 혈장, 대두단백질은 겔화식품의 겔강화와 단백질 보강의 목적으로 다양하게 사용되고 있으며, 이 때 첨가단백질의 겔화 특성은 가장 중요한 피능적 특성중 하나이다. 이러한 겔화에는 단백질의 종류, 가열온도와 시간, 염의 유무, pH등의 환경이 복합적으로 작용하여, 소수성 상호작용, 공유결합, 이온결합, S-S결합 및 수화력 등이 겔을 형성한다. 단백질의 겔화에 미치는 변수에 대한 많은 연구가 이루어졌지만 단백질의 겔화 특성에 있어 가장 많은 구성비율을 차지하는 수분과 수화력에 관한 연구는 미미한 실정이다. (중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.315-318
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• 2009

본 논문에서는 해상 기초 교각 매스 콘크리트의 수화열 저감 방안을 다루었다. 저발열 콘크리트, Mesh형 거푸집 공법 등에 대한 실험을 수행하여 각각의 수화열 저감효과를 평가하였다. 현장 실험은 사용 시멘트와 거푸집의 종류, 거푸집의 사용 면수에 따라 총 4 type으로 구성하였으며, 이에 대한 실험 결과와 유한 요소 해석 결과를 비교, 검증하여 최종적인 수화열 저감 성능을 도출하고자 하였다. 실험을 통해, 저발열 시멘트와 유로폼을 사용하는 것이 수화열 저감을 위해 효과적인 방법으로 판명되었으나 추가 공사비의 발생으로 효율성이 떨어질 것으로 판단된다. 또한 Mesh형 거푸집 적용 면 수와 온도 상승 저감 효과는 비례하는 것을 알 수 있었지만 내 외부 온도차가 다소 크게 나타나 수화열에 의한 균열 발생 확률면에서는 다소 불리하게 나타났다. 그러나 실험 단계에서 생략된 양생과 관리를 통하여 균열의 저감효과를 거둘 수 있을 것으로 판단되며, 추가적으로 거푸집 해체 단계를 생략함으로 공기단축 측면에서 유리할 것으로 판단된다.

• Analytical Science and Technology
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• v.24 no.6
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• pp.460-466
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• 2011

The activity of an antimicrobial peptide, magainin 2, on lipid membranes was investigated using solid-state NMR and a new sampling method that employed mechanically aligned bilayers between thin glass plates. The experiments were performed at two hydration levels. At 95% hydration about 15% of the lipid bilayers were disrupted and at full hydration 20% were disrupted. From the comparison of two equilibrium states established by two sampling methods the importance of peptide binding to the lipid bilayer for whole membrane disruption was demonstrated.