• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2007.05a
• /
• pp.558-560
• /
• 2007

l-PLA와 d-PLA사이의 complex형성은 화학 양론적으로 동일 몰비에서 강력한 상호 작용력에 기인한다. 이러한 특성을 이용하여 PLA블렌드 계에서 stereochemistry를 이용하여 블렌드 한 성분에 defect를 부여함으로서 complex정도를 조절함으로서 다성분 고분자계의 표면 조성의 조절(표면 물성의 조절)과 생분해성의 조절이 가능함을 보였다.

• Journal of the Korean Chemical Society
• /
• v.39 no.9
• /
• pp.741-748
• /
• 1995

Various catechol derivatives inhibiting 5-lipoxygenase were studied with theoretical calculations and QSAR study. It was hypothesized that receptor site model could accept the active site of the catechol derivatives. The molecular length, molecular surface area, C5 net charge, HOMO/LUMO energy, van der Waals surface area and volume were used as variables to find the relationships between activity and physicochemical parameters.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1994.04a
• /
• pp.53-54
• /
• 1994

Polyimide는 열, 화학적으로 안정하고 기계적성질이 우수하고, 기체분리특성이 비교적 좋다. Polyimide의 화학구조와 기체투과도와의 관계는 화학구조를 체계적으로 변화시키면서 많이 검토되어왔다.[1-2] Polyimide는 강직한 직쇄구조, bulky group에 의한 분자쇄운동성을 제어함과 동시, 약한 분자간 상호작용이 polymer chain의 유효층진을 억제하여 기체투과도를 높여준다. 국부분절운동(local segmental mobility)이 감소된 구조는 기체투과선택도를 향상시켜주는 경향을 보여주었다. [3] kim et al. 과 Stern et al은 6FDA나 fluorine-containing diamines으로 만든 polyimde가 매우높은 투과도를 보여준다고 보고했다. 본 연구에서는 6FDA-2, 4TDA hobopolymer에 BAAF를 가하여 copolyimide Membrane을 제막하여 BAAF 조성에 따라 투과선택도를 측정하는 homopolymer와 copolymer에 따른 변화를 관찰하였다.

• Korean Chemical Engineering Research
• /
• v.55 no.4
• /
• pp.467-472
• /
• 2017

Alkaline electrolytes consisting of 6 M KOH and polymer (PEO, PVA, and PAAK) are coated on PAN nonwoven fabrics as a separator, and the electrochemical properties of the activated carbon supercapacitor adopting them are investigated in terms of redox behavior, specific capacitance, and interfacial impedance. Although the interaction between polymer and KOH are comparatively inactive in PEO and PVA, PAAK (3 wt.%)-KOH forms a hydrogel phase by active interactions between $COO^-K^+$ in side-chain of PAAK and $K^+OH^-$ from alkaline electrolyte solution, improving ionic conduction of electrolytes and the electrochemical properties of the supercapacitor. As a result, the activated supercapacitor adopting the PAAK-KOH shows the superior specific capacitance of $46.8Fg^{-1}$ at $100mVs^{-1}$.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.234-235
• /
• 2002

최근 상호 결합된 chaotic 진동자들 간의 동기화의 문제는 그 시스템이 가지는 여러 가지 응용성 때문에 여러 과학 분야와 기술 분야 예를 들면 동력학, 레이져 동력학, 전자회로, 화학반응, 생물학적인 시스템 등에서 폭넓게 연구되어지고 있다. 더욱이 작은 파라미터의 차이를 제외하고 거의 유사한 chaotic 진동자들간의 상호작용에서 찾아 볼 수 있는 위상 동기화 현상은 뇌세포 조직과 같은 생물학적인 시스템들 사이에 흔히 찾아 볼 수 있는 기본적인 현상이다. (중략)

• Journal of the Korean Chemical Society
• /
• v.50 no.6
• /
• pp.494-505
• /
• 2006

This study was performed for 7th grade students to analyze by leader style, the verbal interactions between students in a small group in an MBL(Microcomputer-Based Laboratory) experiment class. The study was performed after arranging the students into four kinds of groups, including groups with leaders of inclusive, persuasive, and alienating styles and a group with no clear leader. The analysis of total frequencies of verbal interaction revealed that the group with an inclusive leader showed the highest frequency of verbal interaction, followed by the group with a persuasive leader, an alienating leader and lastly, the group with no clear leader. The group with an inclusive leader showed the highest frequency of interaction from a cognitive aspect related to question(Q), response(R), making suggestion(MS), and receiving opinions(RO), while interactions from an affective aspect related to behavioral participation(BP) and students' attitudes(SA) were observed more often in a group including an alienating leader than in any other group. An analysis of characteristics of verbal interaction according to leader style showed that a group with an inclusive leader had a permissive atmosphere. It also showed that all members of the group actively participated in discussion and they had a sense of belonging and self-pride with their group. In a group with a persuasive leader, the leader took the lead of most experimental and discussion activities and he was rarely challenged by other students in the group. Rather, other group members showed a tendency to depend on their leader. In a group with an alienating leader, the relationship between leader and members of the group was not harmonious and unfiltered expressions of dissatisfaction and ignorance often took place. The leader's lack of concern about members' low achievement became an obstacle in active discussion. In a group with no clear leader, most interactions during discussion were short and simple. Many answers to the question given by their members were not clear and the interactions were sometimes interrupted for a short while.

• Journal of KIISE:Databases
• /
• v.30 no.6
• /
• pp.573-584
• /
• 2003

Recent massive data generation by genomics and proteomics requires bioinformatic tools to extract the biological meaning from the massive results. Here we introduce ROSPath, a database system to deal with information on reactive oxygen species (ROS)-mediated cell signaling pathways. It provides a structured repository for handling pathway related data and tools for querying, displaying, and analyzing pathways. ROSPath data model provides the extensibility for representing incomplete knowledge and the accessibility for linking the existing biochemical databases via the Internet. For flexibility and efficient retrieval, hierarchically structured data model is defined by using the object-oriented model. There are two major data types in ROSPath data model: ‘bio entity’ and ‘interaction’. Bio entity represents a single biochemical entity: a protein or protein state involved in ROS cell-signaling pathways. Interaction, characterized by a list of inputs and outputs, describes various types of relationship among bio entities. Typical interactions are protein state transitions, chemical reactions, and protein-protein interactions. A complex network can be constructed from ROSPath data model and thus provides a foundation for describing and analyzing various biochemical processes.

• Journal of the Korea Concrete Institute
• /
• v.29 no.1
• /
• pp.65-75
• /
• 2017

C-S-H phase is the most abundant reaction product, occupying about 50~60% of cement paste volume. The phase is also responsible for most of engineering properties of cement paste. This is not because it is intrinsically strong or stable, but because it forms a continuous layer that binds together the original cement particles into a cohesive whole. The binding ability of C-S-H phase arises from its nanometer-level structure. In terms of chloride penetration in concrete, C-S-H phase is known to adsorb chloride ions, however, its mechanism is very complicated and still not clear. The purpose of this study is to examine the interaction between chloride ions and C-S-H phase with various Ca/Si ratios and identify the adsorption mechanism. C-S-H phase can absorb chloride ions with 3 steps. In the C-S-H phase with low Ca/Si ratios, momentary physical adsorption could not be expected. Physical adsorption is strongly dependent on electro-kinetic interaction between surface area of C-S-H phase and chloride ions. For C-S-H phase with high Ca/Si ratio, electrical kinetic interaction was strongly activated and the amount of surface complexation increased. However, chemical adsorption could not be activated for C-S-H phase with high Ca/Si ratio. The reason can be explained in such a speculation that chloride ions cannot be penetrated and adsorbed chemically. Thus, the maximum chloride adsorption capacity was obtained from the C-S-H phase with a 1.50 Ca/Si ratio.

• Journal of the Korean Chemical Society
• /
• v.42 no.2
• /
• pp.156-160
• /
• 1998

Probe diffusion with latex particles in two different types of chemically cross linked gel has been studied. The diffusion of particles in silica gel is decreased by decreasing the gel correlation length but the particles' diffusion in the acrylamide gel still shows the heterogeneity of the gel. By increasing the contents of the gel network the silica gel makes a more homogeneous and compact structure than that of acrylamide gel which has partial heterodyning. Dynamic light scattering study with the probe particles in two different gels reveals the heterogeneity of the gel network. The latex particles trapping in the gel has been investigated by using non-ergodic concepts.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1998.11a
• /
• pp.195-200
• /
• 1998

토양내에 있어 중금속의 총량 분석만으로는 오염 토양에 대한 환경 평가를 위한 충분한 자료가 되지 못한다. 또한 중금속의 토양내 위해성은 중금속과 토양과의 화학적 상호작용에 의해 결정되기 때문에 중금속의 화학적 형태를 규명하는 것은 토양 환경에 있어서 그들의 이동성과 거동 특성을 평가하는데 중요한 자료가 된다. 연속 추출법은 구봉 광산의 광미로 부터 Cd, Cu, Pb을 화학적 형태에 따라 분리하고, 인위적으로 중금속을 포화시킨 광미와 두밭토양에 있어 중금속의 토양내 거동 특성을 예측하기 위하여 이용되었다. 광미중 Pb의 대부분은 Fe-Mn oxide, carbonate의 결합 형태로 존재하였으며, Cu와 Cd은 각각 71.8%와 42.9%가 유기물, carbonate의 결합형태로 존재하였다. 상당량의 Cd(94.9%), Cu(95.1%), 그리고 Pb(85.8%)은 토양내 잠재적으로 이동 가능한 형태로 존재하였다. 유성과 논산의 밭토양 에 가해진 Cd는 대부분 이동성이 가장 높은 치환태로 존재하였으며, 유성과 논산 토양에서 각각 67.9%와 93.2%가 치환태로 존재하였다. 토양에 가해진 Cd, Cu, Pb은 대부분 이동이 용이한 형태로 존재하였으며, 토양과의 결합세기는 Pb > Cu > Cd 순으로 감소하였다.