• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.308-313
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• 2014

Recently, for longevity of resident building, the main trend is that the change of the inside space organization of resident building from wall construction to rhamen construction, which resulted in increase in use of lightweight composite panel. Thus, in this study, authors analyzed the engineering property of oxide of magnesium depending on the magnesium chloride addition ratio. The results of this research is expected to contribute on providing a fundamental material for the surface materials of lightweight composite panel. As the result of the experiment, as fluidity increased, air content decreased and initial set and final set as the magnesium chloride addition ratio increase. In the aspect of flexural strength and compressive strength, the test specimen showed the highest strength at 40% of the magnesium chloride addition ratio. At 20% of the magnesium chloride addition ratio, the test specimen showed the lowest water absorption rate. As the magnesium chloride addition ratio increases, the expansibility tends to increase as well in the aspect of shrinkage strain. After observing microstructure, we can see hydration products in the form of needle. It appeared high flexural strength because the hydration products have mineral fibrous tissue shape, which also contribute to the cause of the expansibility.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.104-107
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• 2009

Mitrula paludosa (Geoglossaccae, Helotiales, Ascomycetes) is reported about morphological and ecological characteristics for the first time in Korea. The mushroom fruited on rotten pine leaves or fine twigs in ditches with flowing or standing water in Sogri Mountain National Park from May to June. The apothecium of M. paludosa is 20 to 50 mm tall. The cap is bright yellow to orange, cylindrical to wrinkled ovoid and $5{\sim}10\;{\times}\;10{\sim}20$ mm. The stem is whitish and cylindrical distinctly set off from the cap. The ascospore is hyaline, smooth long elliptical fusoid with round ends and $13{\sim}17\;{\times}\;1.5{\sim}2.0{\mu}m$. The ascus is unitunicate, $90{\sim}110\;{\times}\;5{\sim}6{\mu}m$, and has eight spores biseriately lined to the inoperculate apex. Paraphyses are septate filiform, $95{\sim}120\;{\times}\;1.0{\sim}1.5{\mu}m$, $7{\sim}10{\mu}m$ longer than the asci.