• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.3
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• pp.315-324
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• 1994

The effects of impurities of the quartz raw materials on the trasformation of quartz to cristobalite were investigated. As the increase of impurities content, the amount of cristobalite crystal increased, whereas the fusion temperature of quartz and the formation temperature of cristobalite decreased. And the courses of the transformation of quartz to cristobalite were examined. The course of quartz $\rightarrow$ transitional noncrystalline phase $\rightarrow$ melt (T) and quartz $\rightarrow$ transitional noncrystalline phase $\rightarrow$ cristobalite $\rightarrow$ melt (C) were always coexisted on the transformation of quartz. In the case of high purity quartz raw material, the T course was predominant, while in low purity quartz raw material, the C course was predominant. And the calculated density of heat treated sand by the quantitative analysis of quartz and cristobalite phase by XRD is well agreed with the measured density by pycnometer. On the melting proces of quartz glass, the volume expansion of sand at a certain temperature can be estimated with the calculated density data.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.94-95
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• 2002

식품은 생체유지에 필요한 영양물질을 공급하는 영양적 기능과 식품의 색, 풍미등 식사의 즐거움을 주는 감각기능과 미량성분으로서 생체의 재계통을 조절하는 생체조절기능을 가지고 있는데, 최근에는 생체조절기능에 관한 연구가 활발히 진행되고 있다. 식품 중에 미량으로 존재하고 있는 성분으로서 생체조절에 관여하는 물질은 대부분이 단백질이나 호르몬류이며, 이들 성분이 면역계, 신경계 및 내분비계 등에 관여하는 조절기구를 생화학적으로 해명하기 위하여 생리활성물질의 검색, 구조의 결정, 체내의 흡수, 기능발현 및 식품성분 상호간의 영향 등에 관한 연구가 수행되고 있다. (중략)

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.307-311
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• 2005

본 연구는 동결농축유의 미량성분을 분석하고 관능적 특성을 알아보기 위하여 실시하였다. 농축유의 수용성비타민은 동결농축유가 진공농축유보다 비타민의 감소율이 적었고, 같은 동결농축유의 경우에 17% 고형분인 농축유가 27% 고형분인 농축유보다 비타민의 감소율이 적었다. 지용성비타민도 동결농축유가 진공농축유보다 비타민 감소율이 적었으며, 수용성비타민 보다는 그 감소율이 크지 않았다. 유리아미노산은 진공농축유보다 동결농축유에서 많이 측정되었고 단쇄유리지방산은 진공농축유가 동결농축유보다 생성량이 많았으며 고형분이 많을수록 많이 측정되었다. 지방산화도는 단쇄유리지방산의 결과와 같이 동결농축유보다 진공농축유가 더 높게 측정되었다. 관능검사는 cooked flavor, oxidized flavor, cheesy flavor, fat-taste, oxidized taste, off-taste에서 동결농축유가 진공농축유보다 양호하게 평가되었다. 결과적으로 동결농축유가 진공농축유보다 미량성분의 손실이 적고 관능적으로 양호하게 평가되었기 때문에 영양학적, 관능적으로 우수하다고 사료된다.

• Journal of Conservation Science
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• v.16 s.16
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• pp.89-103
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• 2004

Provenance discrimination of sixty four obsidian artifacts found in the Korean Peninsular has been carried out using major elements, minor elements and magnetic properties. Most of obsidians in this study were classified into the subalkaline series based on the contents of $Al_2O_3,\;CaO,\;and\;Na_2O+K_2O$ in samples. Provenance & obsidians were classified into three major groups using major elements and minor elements analyse. This result suggests that there are no correlations among the three groups whose provenances are different. Although the magnetic properties of obsidians do not yield clear groupings according to the archaeological site, the bivariate plot for the magnetic susceptibility and the saturation isothermal remanent magnetization shows a rough correlation with the results of major and minor elements analyses.

• Journal of the Korean Ceramic Society
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• v.38 no.6
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• pp.522-530
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• 2001

발굴된 과거 고려청자의 화학성분조성과 물리적 특성에 대한 평가를 하고 미량성분의 청자의 발색에 미치는 영향을 고찰한 결과, 고려 청자 태토는 Fe$_2$O$_3$가 2%, TiO$_2$가 0.8% 함유되어 있었으며, 청자유는 석회.장석유로서 Fe$_2$O$_3$가 1.0~1.2%, TiO$_2$가 0.16% 포함되어 있었다. 비색청자의 경우 미량성분인 MnO$_2$가 P$_2$O$_{5}$의 함량이 0.37%와 0.76%, CuO는 300~500ppm 정도 함유하고 있었다. 반사율 측정 결과 일반적인 청자가 540~570nm의 장파장대에서의 반사율이 급격히 떨어지는데 반하여, 13세기 비색 청자의 것은 적색 파장대에서 10%이상 높았다. CoO는 미량 첨가로도 유약의 청색 파장대 반사율이 높고, 적색 파장대의 반사율이 급격히 떨어지며 청자 발색에 부정적인 영향을 미쳤다. CuO는 0.05%를 첨가했을 경우 적색 파장대에서 반사율 곡선이 높게 나타나고 있어 비색 청자발색에 효과적이었다. 또한 명도를 나타내는 L*값도 CuO가 첨가된 유약이 가장 높았고, 비색청자의 색상은 녹청자에 비해 맑고 깊은 색감을 보였다.

• Cement Symposium
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• no.32
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• pp.5-14
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• 2005

• KOREAN POULTRY JOURNAL
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• v.3 no.7 s.21
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• pp.86-89
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• 1971

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.793-800
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• 2007

A total of 48 samples of street dust were collected in Daegu area during April and May 2006, were sieved below 100 ${\mu}m$, and analysed by ICP for the analysis of 14 elements after an acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na and V were influenced by natural sources such as soil and dust, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by urban anthropogenic sources such as fuel combustion and waste incineration. The measured values were remarkably higher in components from natural sources than in components from urban anthropogenic sources. The concentrations of trace elements in Daegu area were generally higher than in other foreign cities. Samples originated from industrial and commercial areas had higher concentrations of trace elements and pollution indices of heavy metals than those from residential and green areas. The correlation analysis among trace elements indicated that the correlations among components from urban anthropogenic sources were much significant, while those among components from natural sources were less correlated. In addition there were significant correlations between traffic density and components from urban anthropogenic sources.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.168-176
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• 2012

A total of 48 dust samples were collected from large shopping mall parking lots in Daegu metropolitan city in March 2011. Samples were sieved through a 100 ${\mu}m$ mesh and the concentration of 14 elements have been determined using by ICP after acid extraction. Results showed that Ca, Fe, K, Mg, Mn, Na and V were affected by natural sources while Cd, Cr, Cu, Ni, Pb and Zn were affected by anthropogenic sources. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. Anthropogenic trace element concentrations of ground roof dust were higher than those of ground and underground indoor dust. A large percentage of trace elements came from natural sources rather than anthropogenic sources. The percentage composition of chemicals of ground roof dust were higher than those of ground and underground indoor dust. This study showed that investigated parking lots were rarely contaminated with hazardous heavy metals. The heavy metal pollution of ground roof were higher than those of ground and underground indoors. The correlation analysis among trace elements suggest that components in ground roof were more highly correlated than those in ground and underground indoor. Also anthropogenic trace element levels were well correlated with parking lot age and parking density.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.287-295
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• 2010

Dust samples have been collected from streets, schools, subway stations and households in Daegu metropolitan city. Samples were sieved through a 100 ${\mu}m$ mesh and the concentration of 14 elements have been determined using by ICP after acid extraction. Results showed that Ca, Fe, K, Mg, Mn, Na and V were influenced by natural sources while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. In particular, school dust had higher levels of Ca and Pb and subway station dust had higher levels of Cu and Zn. The percentage composition of chemicals from subway stations, households, and schools were remarkably higher in components from anthropogenic sources than that from streets. It is well recognized that anthropogenic sources were affected by indoor dust. Results of pollution index of hazardous heavy metals indicated that schools, households, and subway stations were more contaminated than streets and urban areas typically had higher pollution index than rural areas. The correlation analysis among trace elements seem to suggest that there were correlations between components of soil/road dust resuspension, and components of waste incineration and fuel combustion.