• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.799-808
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• 2010

In this study, we conducted a textbook analysis and a conceptual test in order to investigate misconceptions of preservice chemistry teachers in understanding motions of molecular gases. As a result, we found out that many of the general chemistry textbooks not only introduce motions of molecular gases by explaining basic conceptions and using simple models, but also omit the explanation on center of mass when dealing with rotational motion. The physical chemistry textbooks, however, mainly approach motions of molecular gases in terms of spectroscopy and use various models to explain more intensified concepts, referring the center of mass in rotational motions. Meanwhile, pre-service chemistry teachers' confidence and understanding in the motions of molecular gases were very low and pre-service teachers also had many misconceptions about them. We believe this is because they had a tendency to depend largely on their intuition based on the pre-conceptions and the visual materials in the textbooks.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.70.3-70.3
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• 2019

Understanding how the filamentary structure affects the formation of the prestellar cores and stars is a key issue to challenge. We use the Heterodyne Array Receiver Program (HARP) of the James Clerk Maxwell Telescope (JCMT) to obtain molecular line mapping data for two prestellar cores in different environment, L1544 in filamentary cloud and L694-2 in a small cloud isolated. Observing lines are $^{13}CO$ and $C^{18}O$ (3-2) line to find possible flow motions along the filament, $^{12}CO$ (3-2) to search for any radial accretion (or infalling motions) toward the cores of gas material from their surrounding regions, and $HCO^+$ (4-3) lines to find at which density and which region in the core gases start to be in gravitational collapse. In the 1st moment maps of $^{13}CO$ and $C^{18}O$, velocity gradient patterns implying the flow of material were found at the cores and its surrounding filamentary clouds. The infall asymmetry patterns of HCO+ and $^{13}CO$ line profiles were detected to be good enough to analyze the infalling motions toward the cores. We will report further analysis results on core formation in the filamentary cloud at this meeting.