• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.73-80
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• 2011

In order to develop the environmental-friendly new materials based on soybean protein which is plantable macromolecule, thermal characteristics of the soybean protein resin (SPI) modified by plasticizers (1,3-propandiol, glycerol) and cross linking agents (glutaraldehyde, epichlorohydrin, glyoxal, urea) were analyzed by TGA. Mechanical properties of modified SPI were investigated and fracture was observed by SEM. As the result, flexibility of SPI film was increased by adding plasticizers; 1,3-propandiol and glycerol. Plasticization effect of glycerol was relatively greater than that of 1,3-propandiol. With the application of crosslinking agents (glycerol, epichlorohydrin and glyoxal), strength and thermal stability of SPI increased with their content. On the other hand, in case of addition of urea, thermal stability of SPI decreased and its strength was reduced because cross-linking between urea and SPI was somewhat difficult. Fracture surfaces and domain interfaces of the modified SPI resins were observed with SEM.

• The Journal of Korean Physical Therapy
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• v.13 no.1
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• pp.229-235
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• 2001

Clinical interest has lately been roused by evidence that comprehension of synaptic plasticity may be based on the theoretical opinion. This paper describes perception of synaptic plasticity. Especially processes of long term potentiation(LTP) and long term depression(LTD) are discussed. Recently, it is assessed to genetical parts from development of molecular biology. Therefore this review also represents aspect of molecular events of synaptic plasticity.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1986.08a
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• pp.89-94
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• 1986

1. 밀가루 반죽 내에서 유지류는 gluten의 수화를 감소시키고 따라서 glu1en의 망상 구조형성을 방해함으로써 연화작용을 하게 된다. 이 결과 pastry와 biscuit, cracker 류의 crispness를 증가시키고, shortened cake에 tenderness를 부여한다.2. 유지류의 shortening power는 가소성이 커서 밀가루에 잘 분산될수록, 유지의 사용량이 많을수록, 반죽 정도가 적당할 대, 반죽을 섞는 과정에서 액체 성분 첨가 후의 젓는 정도가 적을수록 커진다. 3. Yeast-raised baked food에서 shortening등 유지류의 역할은 빵의 용적, 탄성 및 기계적 내성을 증가시키고 노화를 지연시키며 질감을 좋게한다. 이러한 shortening의 기능은 밀가루 자체의 지방질과도 밀접한 상관 관계가 있다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.20-23
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• 1996

최근에 인공생명이나 진화적 계산론이라는 이름의 새로운 지능정보처리 방식이 미국과 일본을 중심으로 활발히 연구되고 있다. 이것은 지금까지 개별적으로 제안된 두뇌의 가소성이나 개체의 발생, 적응과 진화 등 생물의 특성으로부터 파생된 모형들을 총동원하여 정보처리의 새로운 가능성을 모색하고자 하는 것이다. 본 논문에서는 인공생명의 연구가 어떻게 시작되었으며, 현재의 기술수준이 어느 정도인지에 대하여 소개하고자 한다. 아울러, 인공생명으로부터 가능한 새로운 형태의 정보처리 기능창출을 목표로 하는 연구동향을 살펴보고 앞으로의 방향을 전망해 본다.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.225-228
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• 2018

Plasticizers added to thermoplastic polymers are known to shorten the life of products due to the elution to outside, and some of them are harmful to our environment and human body. Since the use of phthalate plasticizers suspected of being carcinogens has been gradually prohibited, there is a need for environmentally friendly plasticizers that can replace them. Most of the substances have a low compatibility with resin, high cost and lack of safety verification. Therefore, in this study, four kinds of norbornene dialkyl ester compounds possessing excellent physical properties, which are also reported as safe compounds from the toxicity evaluation, were added to PVC resin to evaluate the possibility of human exposure by leaching, and also the potential usage as plasticizer candidates alternative to commercial ones including DEHP, DINCH and DOTP. The test was carried out according to the American standard test method (ASTM). The results showed that di-2-ethylhexyl-5-norbornene-2,3-dicarboxylate (DEHN) in aqueous solvents and diisopentyl-5-norbornene-2,3-dicarboxylate (DIPN) compounds in oil solvents were superior or equivalent to DEHP. In addition, all four norbornene compounds showed lower values than 100 ppm, which is considered to have an influence on the environment, indicating that the polar norbornene structure affects the elution.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.56-57
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• 1993

고분자 막을 통한 투과증발에서의 전달기구는 액체 혼합액의 막으로의 용해, 막을 통한 확산, 막 하부에서의 증발을 거쳐 분리가 일어난다고 알려져 있다. 이때 투과증발의 선택도는 수착선택도와 확산선택도의 곱으로 표현 될 수 있다(1). 물의 선택적 분리의 관점에서 친수성 고분자 막을 이용하는 경우, 선택도는 대부분 수착선택도에 기인하며, 우수한 투과속도와 함께 집중적인 연구의 대상이 되었으나 가소화 현상이 심하게 일어나는 단점이 있다. 한편 소수성 고분자 막을 이용하는 경우의 투과 증발 선택도는 대부분 확산선택도에 기인하며, 가소화 현상은 억제되나 투과속도가 낮은 단점이 있다. 그러나 소수성 고분자 막을 이용하는 경우에도 물에 대해 높은 선택도를 달성 할 수 있는데, 예를 들어 polystyrene(PS)으로 만들어진 고분자 막 및 fluoroalkylacrylatemethylstyrene copolymer로 만들어진 고분자 막은 물-에탄올 공급액으로 부터 물에 대한 높은 선택성을 보여주고 있다(2,3). 그러므로 막분리층의 두께를 가능한 한 얇게 하면 분리에 유효한 막이 될 수 있다.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.745-752
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• 2012

This paper studies the effect of the compressive strength for combined alkali-activated slag mortars. The effect of activators such as alkali type and dosage factor on the strength was investigated. The alkalis combinations made using five caustic alkalis (sodium hydroxide (NaOH, A series), calcium hydroxide ($Ca(OH)_2$, B series), magnesium hydroxide ($Mg(OH)_2$, C series), aluminum hydroxide ($Al(OH)_3$, D series), and potassium hydroxide (KOH, E series)) with sodium carbonate ($Na_2CO_3$) were evaluated. The mixtures were combined in different dosage at 1M, 2M, and 3M. The study results showed that the compressive strength of combined alkali-activated slag mortars tended to increase with increasing sodium carbonate. The strength of combined alkali-activated slag mortars was better than that of control cases (without sodium carbonate). The result from scanning electron microscopy (SEM) analysis confirmed that there were reaction products of calcium silicate hydrate (C-S-H) and alumina-silicate gels from combined alkali-activated slag specimens.

• The tire
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• s.5
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• pp.17-22
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• 1967

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.348-349
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• 2003

PVA는 열가소성 고분자임에도 불구하고 융점(230~25$0^{\circ}C$)에 이어 바로 측쇄의 분해(270 $^{\circ}C$)가 시작되므로 공정상 많은 어려움을 가지고 있다. 그러나 요드와 같은 극성의 가소제를 사용하면 결정영역 까지도 가소화 시킬 수 있는 이점이 있어 PVA 유연성, 가공성 둥의 성질을 개선시킬 수 있다. [1-3] 특히 본 연구에서 성형 전 요드화된 폴리비닐알코올 필름을 제작하여 구조를 살펴본 결과, 결정성이 많이 감소하다가 요드흡착량이 150%의 경우에서는 무정형상태까지 나타났다. (중략)

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.762-766
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• 2006

To improve water resistance of paperboard used to manufacture the corrugated boxes, effect of surface coating of the liner- board with Na-alginate was investigated by determining the optimum processing conditions such as a optimum alginate concentration for surface coating, plasticizer content, concentration of divalent cations their immersion times, For the surface coating of the liner-board, 2.5% Na-alginate solution was found to be the optimum concentration, and the concentration of glycerol used as plasticizer was effective when 35% alginate concentration was use was Used Immersion of the alginate coated paperboard for 3 min in a $CaCl_2$ solution improved the water resistance properties. As a divalent cation for the insolubilization of the alginate films, $Cu^{2+}$ was found to be as effective as $Ca^{2+}$. Among the platicizers tested, sorbitol was the most effective in reducing water vapor permeability and water solubility of alginate coated paperboard.