• Elastomers and Composites
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• v.58 no.1
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• pp.1-10
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• 2023

In this study, we investigate the liquid crystal (LC) alignment of LC cells created from plant-based polysaccharide derivatives, such as guar gum. Guar gum films exhibit satisfactorily high optical transparency in the visible light region (400-750 nm). For example, the transmittance of polyimide films, which are the most typically used LC alignment layers, is 87%, whereas that of guar gum films deposited onto a glass substrate at a wavelength of 550 nm is approximately 99%. The observed LC alignment depends on the rubbing depth. For example, an LC cell comprising a guar gum film fabricated via rubbing at rubbing depths of 0.1, 0.2, 0.3, and 0.4 mm exhibits a planar LC alignment, whereas it exhibits a vertical LC alignment at a rubbing depth of 0.5 mm. Additionally, the LC alignment is shown to be correlated with the total surface energy of the guar gum films. When the total surface energy of a rubbed guar gum film exceeds 58.10 mJ/m², an LC cell comprising the guar gum film exhibits a stable and vertical LC alignment. Therefore, guar gum can be used to realize the vertical alignment system of LC via a simple adjustment of the rubbing depth.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.130-139
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• 2006

Natural history museums used to be called an "informal learning institute". It is based on the assumption that their exhibition and exhibits are supposed to reflect school science curriculum and support school science programs. This study is to explore how this assumption is verified in terms of content-wise connections between school science and museum exhibits. In this study, 461 Earth Science related exhibits were selected from the Smithonian Museums and the American Museum of Natural History in the U.S. and analyzed with several instruments. The instrument targeting on Earth Science curriculum was framed based on the Third International Mathematics and Science Study (1993) and the National Science Curriculum Standards (1996). Other than content-wise connections, this study investigated exhibition characteristics related to better learning of science: these characteristics were types of activities, exhibition media, exhibition technology, and presentation methods. The nature of science shown in exhibits were examined as well. Natural history museums were reconsidered for their relevance and potential as informal educational venues from this study.

• Journal of the Korean earth science society
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• v.29 no.6
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• pp.506-519
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• 2008

This article explores the potential learning materials and methods of science practice from exhibits, and how those are presented in natural history museums as a feasible science inquiry community. The idea of science inquiry community was offered as a form of science practice that ended with science learning. A grasp of 'scientific practice to learning' is understood as a way to conceive scientific methods as well as facts and understanding knowledge. To get educational implications on the scientific practice of 'earthquake' as a socioscientific topic in the communities, we analyzed 1) the relationship between earth science curriculum and exhibits related to 'earthquake', 2) the educational goals and intentions of educators, and 3) the characteristics of the exhibits in the American Museum of Natural History and in the Smithsonian National Museum of Natural History. The results of this study showed that those museums presented the exhibits consisting of various and practical cases and events of 'earthquakes' as a socioscientific topic related to their curriculum. At the target museum, it was clearly stated that the pursuing educational goals focused on relations with local interests and socioscientific issues. For making earthquakes relevant to visitors, delivering lived experiences with raw data and interactive media was emphasized in exhibit characteristics.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.925-934
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• 2016

For students, astronomy is not only interesting but also difficult to learn. However, there is a limit in learning astronomy in a school science setting since astronomy is vast subject. Fortunately, science museums can be helpful in overcoming this limitation. Experiences in science museum provide something that any descriptions or illustrations cannot give. Therefore, to maximize the educational effect, it is necessary to look at astronomical exhibits regarding the educational aspects and complement them. For these reasons, the purpose of this study is to investigate characteristics of exhibitions related to astronomy and how much the exhibitions reflect the contents of their science curricula. We selected famous science museums in Korea, America, and Japan and analyzed characteristics of their astronomy exhibition. We analyze these characteristics in the aspects of exhibition technology & media, presentation method and activity types. Also, this study figures out how content of exhibitions are connected to school science curriculum. The results are summarized as follows: First, Science Museums of America and Japan utilize interactive exhibits to raise participation. It implies that Science Museum of Korea needs Interactive Exhibits that provide a realistic experience of the universe. Second, the astronomy exhibits reflect some of the learning elements of their science curricula concerned with astronomy. However, these astronomical contents are included selectively and not according to their required curriculum. It means that many students lack the opportunity to study Astronomy in their schools. Therefore, the astronomy museum must reflect learning elements of science curricula concerned with astronomy in the exhibits.

• Journal of the Korean Home Economics Association
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• v.2 no.1
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• pp.321-327
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• 1960

• Korean Institute of Interior Design Journal
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• no.21
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• pp.42-53
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• 1999

The purpose of this study is to clarify the relationship between the exhibits layout and the spatial organization in exhibition spaces. As an analytical method, the space syntax theory devised by Bill Hillier(1984) was applied for analysing the potential differentiation of exhibition spaces and remodeling method in Seoul City Museum selected for case study. The results are as following. Especially from the convex analysis, axial analysis and exhibits(interpretation); 1) the closed spatial system(1F) has high visibility and high intelligibility in hall area but lacks route continuity, 2) the circulated spatial system(2F) has low global visibility but offers high intelligibility and connectivity due to its coercive circulation, 3) and the organization of exhibition design consists in differentiating space that reintegrates them into another spatial order. Therefore, there process are expected to provide a methodological framework for analysing and interpreting spatial organizations of design, leading to the clear explanation of remodeling.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.90.2-90.2
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• 2015

We present the high-resolution spectrum of the S-type symbiotic star V455 Sco obtained with the Dupont telescope in 2014 June. We note that the Raman-scattered O VI ${\lambda}1032$ at $6825{\AA}$ exhibits a triple-peak profile. Adopting an accretion disk model with an additional contribution from a collimated bipolar outflow, we attempt to fit the profile. We propose that the blue and central peaks are formed via Raman-scattering of O VI line photons from the accretion flow and that the bipolar flow is responsible for the remaining red peak. It is also noted that V455 Sco exhibits the Raman-scattered He II features blueward of $H{\alpha}$ and $H{\beta}$.

• Transactions of Materials Processing
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• v.7 no.5
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• pp.459-464
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• 1998

Effect of the several initial textures such as random texture, rolling texture and cube texture, on the plane strain stretching was studied by interpretation of the finite element method. The calculation of yield locus indicated that the sheet oriented in the cube texture exhibits easy yielding on uniaxial stress state whereas the sheet having either a random or the rolling texture exhibits easy yielding on shear deformation. Upon stretching tests, the thickness strain at the center region contacting the punch was identical regardless of the initial textures while the dependence of the thickness strain on the initial texture was found in the other regions. In general punch loads required or the sheet with an initial cube texture was as expected from calculated yield locus, lower than those for the others.

• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1035-1039
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• 1999

Ferroelectric properties and reliability characteristics of(111) and (100) preferentially oriented tetragonal Pb(Zr0.2Ti0.8)O3 (PZT) thin film capacitors have been investigated as a function of the top electrode thickness. The (111) preferentially oriented film exhibits 180$^{\circ}$domain switching process with better squareness of hysterisis loop and abrupt change of small singal capacitance-voltage comparing to the (100) preferentially oriented film having 90$^{\circ}$ domain switching process. The domain swithcing process of tetragonal phase PZT is different from that of rhobohedral phase. The film with thinner top electrode shows less initial switching polarization due to less compressive stress but it exhibits better endurance characteristics due to enhancing partial switching region.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.35-35
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• 2011

The design and preparation of novel dye rotaxanes have gained much interest recently, since such structure usually exhibits peculiar spectral and optical changes. In spite of the promising results to date, increasing pressure remains to develop novel supramolecular structures based on stimuli-responsive systems. This presentation covers the study of inclusion complexes of cyclodextrins and various chromophores, with an emphasis on our most recent outcome of anisotropic hydrogel. In this system, physical gelation prepared from simple mixture of CD and a azo dye is completed through specific host-guest interaction. The obtained hydrogel exhibits respective morphological transitions based on supramolecular assembly and dissociation, leading to either precipitation or a sol-to-gel transition. It can identify different classes of metal ions, and, among them, naked-eye differentiation of lead ion is possible due to the coordination-induced unthreading of dye molecules. Accompanying structural changes were verified by numerous characterization techniques, including 2D-ROESY, HR-MAS, UV-Visible absorption, small-angle X-ray scattering, and induced circular dichroism measurements. Such properties discussed here will find useful in analytical applications, such as metal ion sensing and removal applications.