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

• School Mathematics
• /
• v.13 no.2
• /
• pp.229-243
• /
• 2011

The mathematics exhibition gives visitors a special chance to experience mathematics materials through a variety of exhibits. Thus, the study should be carried out by examining the impact on students' perception in the area of mathematics education. This study was conducted based on the three domestic mathematics exhibitions. I carried out the study, with the population of the middle and high school students consisted of 393 attendees and 135 volunteers at the exhibitions, to examine (1) the current condition of exhibitions' operating system and exhibits, (2) the reaction to the exhibits' contents, presentation methods, exhibitions' operating systems, and facilities, and (3) the cognitive and affective effects on the students' perception, engagement, and motivation. From the research-based study, I found more pros on the mathematics exhibition than cons. Therefore, in my opinion, the exhibition's role should be defined as an efficient supplementary method to complement the school curriculum. It is also necessary to develop the appropriate exhibits' contents reflecting the students' levels and needs. The government should provide enough financial supports to various mathematics exhibitions in order to install amenities and facilities for visitors.

• Journal of the Korean earth science society
• /
• v.24 no.4
• /
• pp.281-289
• /
• 2003

The purpose of this study is to isolate characteristics of exhibits particularly considering educational perspectives and effectiveness in attracting the attention of visitors in famous Natural History Museums. The target exhibits were selected from the Natural History museum in London, the Australian Museum in Sydney, the American Museum of Natural History in New York, and the Smithsonian Museum in Washington D.C. A total of 107 sample exhibits used in this study from these four museums were selected as representative solid earth science education related exhibitions including fossils, geological history, and minerals. For the investigation, this study developed a checklist with seven items based on reviewing previous literature and articles pertaining to exhibit characteristics of natural history museums and science centers. Also the educational perspectives focused on classifications of exhibitions by Hein (1997). In this study, all the sample exhibit, were taken pictures of and stored on slide films for lated examination. Respectively exciting and positive results were found in all four museums. The analyses, however, indicated weaknesses as well as strengths in the four museum exhibits.

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

• Journal of the Korean Ceramic Society
• /
• v.45 no.3
• /
• pp.172-178
• /
• 2008

This paper described the study of a sphene-pink pigment based on $Cr_2O_3-SnO_2-CaO-SiO_2$ system exhibits stable pink-red color at high temperature. This study is focused on the optimization of the synthesis parameter such as temperature and holding time for the formation the Malayaite crystal. Malayaite crystal is sensitively influenced by the synthesizing temperature, maintaining time and contents of substituting chromium. The crystal phases formed at different temperatures exhibits various color. The optimum temperature is suggested at $1300^{\circ}C$ for 2 h and substituting contents of Cr for Sn is 0.01 mole. The maximum substituting contents is 0.02 mole based on analysis results by XRD, FT-IR, SEM and UV-vis.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.1016-1022
• /
• 2014

The kinetic studies on the reactions of O-methyl N,N-diisopropylamino phosphonochloridothioate with X-anilines and X-pyridines have been carried out in acetonitrile. The free energy relationship with X in the anilines exhibits biphasic concave upwards with a break region between X = (H and 4-F), giving unusual negative ${\beta}_X$ and positive ${\rho}_X$ values with weakly basic anilines. The unusual phenomenon is rationalized by isokinetic relationship. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed based on the selectivity parameter and variation trend of the deuterium kinetic isotope effects with X. The free energy relationship with X in the pyridines exhibits biphasic concave upwards with a break point at X = 3-MeO. A concerted mechanism is proposed based on relatively small ${\beta}_X$ value, and frontside and backside nucleophilic attack are proposed with strongly and weakly basic pyridines, respectively.

• Journal of Digital Contents Society
• /
• v.16 no.6
• /
• pp.943-950
• /
• 2015

In this study, we propose an annotation system exhibits a secondary role using augmented reality in the exhibition environment. Common methods that utilize the description of the picture or photo booklet or audio device to the exhibition and in the form of viewing the exhibits while people describe method is used. We are using augmented reality technology, in addition to these conventional methods to provide a variety of information about the exhibits utilizing text, photos, video and audio of the multimedia medium. Where visitors can use a smart phone in hand deulgoseo, the exhibition becomes a secondary role by applying the Augmented Reality technology in tablet-based devices.

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

• Korean Institute of Interior Design Journal
• /
• v.22 no.1
• /
• pp.291-298
• /
• 2013

A science museum responds independently based on the exhibits and exhibition environments as the visitors are different in purposes, interests and demands. Therefore a science museum should be designed keeping it in mind that there are various ways for visitors to perceive and use the exhibition spaces and exhibits. The purpose of this study is to compare and analyze the characteristics of sensory receptors for the exhibits in National Museum of Nature and Science's Global Gallery, Tokyo, in terms of information transmission and to identify the nature of exhibit medium that can affect the perception and recognition of the exhibits by visitors. Through these 9 sensory receptors, human recognizes first with visual, auditory and olfactory senses and reacts using vestibular organ, proprioceptor (stretch), tangoreceptor, themoreceptor, taste and olfactory senses. Human uses these information processing to recolonize the external environment. This process is similar to the visitor's information transmission process for the exhibition medium. By dividing the analysis results per exhibition theme and developing the information transmission processing types per sensory receptor, we could understand that the distribution conditions are closely connected with the composition of the exhibition scenario in the exhibtion area. Especially, the understanding of how the information transmission is made through sensory receptors could can be the criteria that determines on the factors that can identify the exhibition purposes of a science museum which are eduction and understanding.

• Journal of Science Education
• /
• v.43 no.3
• /
• pp.300-317
• /
• 2019

This study aims to find how storytelling classes using fairy tales related to science museum exhibits have an effect on positive experience about science. For this study, the theoretical background and preceding studies on the relevance of science education and literature were collected and based on the characteristics of assimilation and the educational value of assimilation, naturally connected to the exhibits in relation to their own life, so that individuals could explore science even out-of-school. Four types of activities were developed by linking four fairy tales mentioned in elementary school textbooks to the G science museum exhibits. Seven elementary school teachers verified the validity of the activity materials. Classes through the developed activity materials were conducted four times in a row, one and a half hours at every turn for 10 students. A positive experience about science test was conducted on the students in a study to confirm that this activity has caused significant changes in science academic emotion among sub-domains of positive experience about science. In order to find the factors that affected the science academic emotion, we interviewed the students in the study and their parents. The results of this study show that the use of fairy tales related to science museum exhibits has led to a significant change in science academic emotion by reducing the burden of learning through the exhibition experience at the science museum, which creates scientific curiosity and recognizes them as a playground.