• Title/Summary/Keyword: minor elements

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Rare Metal Chemistry, Microstructures, and Mineralogy of Coal Ash from Thermal Power Plants of Korea (화력발전소 석탄회의 희유금속화학, 미세구조, 광물학적 특성)

  • Jeong, Gi Young;Kim, Seok-Hwi;Kim, Kangjoo
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.2
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    • pp.147-163
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    • 2015
  • Chemical and mineralogical properties of coal ash samples from the nine thermal power plants of Korea were investigated to acquire basic data for estimating the potential of rare metal recovery. Chemical compositions of coal ash were consistent with those of average shale and foreign coal ashes. However, there were small differences between the metal contents of domestic anthracitic and imported bituminous coal ashes. Unburned coal particles were much abundant in the ash of domestic anthracitic coal. Chalcophile elements were relatively enriched in the fly ash compared to bottom ash. Silicate glass was the major component of coal ash with minor minerals such as quartz, illite (muscovite), mullite, magnetite, lime, and anhydrite. Al and Si were the major components of the glass with varying contents of Ca, Fe, K, and Mg. Glass occurred in a form of porous sphere and irregular pumace-like grain often fused with iron oxide spheres or other glass grains. Iron oxide spheres were fine intergrowth of fast-grown iron oxide crystals in the matrix of silicate glass. Chemical, microstructural, and mineralogical properties would guide successful rare metal recovery from coal ash.

Characteristics of $TiH_2$ under High Pressure (고압하에서 $TiH_2$의 특성화 연구)

  • Kim, Young-Ho
    • Journal of the Mineralogical Society of Korea
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    • v.5 no.2
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    • pp.72-78
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    • 1992
  • The Earth outer core accomodates moderately considerable amount of lighter elements than pure iron itself. Hydrogen is one of the possible candidates of minor constituents in the outer core. It would be worth while to extend for the pressure effect on the solubility of hydrogen in the metal-hydrides including iron hydride. In view of hydrogen being one of the potential substitutes for petroleum, searching a more efficient way for storing hydrogen in the form of hydrides is of considerable value. For two purposes, $TiH_2$was selected among lot of hydrides for its characteristics under pressure and temperature. There have been two kinds of experiment carried out on $TiH_2$ under different experimental conditions. As one of these attempts, polycrystalline $TiH_2$ was loaded up to 15 GPa stepwise at the constant temperature 500${\circ}$ using a piston-cylinder diamond anvil cell equipped with a miniature furnace of an electric power supply. The X-ra diffraction technique was employed on the quenched samples after the simultaneous high pressure and temperature treatments. During these high pressure-temperature runs, and irreversible phase of $TiH_2$ has been observed at the pressures higher than 11.3 GPa, which would be assigned to the orthorhombic crystal system as one of the new phase(s) of $TiH_2$. Molar volume change on this phase transition is ∼10%.

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Effects of Condensed Molasses Soluble on Chemical and Biological Properties of Soil, and Nitrogen Mineralization (당밀농축용액이 토양의 화학 및 생물학적 성질과 질소의 무기화에 미치는 영향)

  • Kang, Gwan-Ho;Kang, Byung-Hwa;Park, Ki-Do;Chung, Keun-Yook;Sohn, Bo-Kyoon;Ha, Ho-Sung;Heo, Jong-Soo;Cho, Ju-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.37 no.2
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    • pp.124-130
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    • 2004
  • This study was carried out to evaluate the effects of condensed molasses soluble (CMS) treatment on the mineralization of N, chemical properties and soil microbial population under the incubation condition with unsaturated water content during the 7 weeks at $25^{\circ}C$ in the different levels of CMS application. The results indicated that the total nitrogen content of soil was increased with increasing application rate of CMS and this trend was maintained up to 7 weeks. With CMS treatment content of $NH_4-N$ was gradually decreased. However, the content of $NO_3-N$ in the soil was gradually increased with incubation time due to the nitrification under the unsturated water condition. The CMS treatment increased the microbial populations such as bacteria, actinomycetes and fungi, which may be due to the availability of more nutrients such as amino acids, sugars and other minor elements from CMS. The pH of soil was found to be reduced by the addition of CMS, Whereas, electrical conduvtivity of soil was correspondingly increased with increasing application rate of CMS.

Chemical Composition and Lead Isotope Ratio of Poong-Tag(Wind Bell) from Winggyeong Site, Cyeongju (경주 왕경지구 금동풍탁(金銅風鐸)의 성분조성과 납동위원소비)

  • Chung, Young-Dong;Kang, Hyung-Tae;Huh, Il-Kwon;Cho, Nam-Chul
    • Journal of Conservation Science
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    • v.19
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    • pp.67-72
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    • 2006
  • The chemical compositions and lead isotope ratio of Poong-Tag(wind bell) bell excavated from Wanggyeong site, Gyeongju have analyzed by ICP and TIMS. The analysis result of chemical composition of Poong-Tag shows that it consists of 92:4 ratio of Cu:Sn. Other 8 minor elements(Pb, Zn, Fe, Ag, Ni, As, Sb and Co) show the concentration of below 0.2% respectively. This result means that Poong-Tag have made using highly purified Cu and Sn ore. For the study of provenance of raw material with the lead isotope ratio, the origin of the raw material of Poong-Tag can not be presumed owing to beyond the scope. The observation result of microstructure of Poong-Tag show the dendrite structure made through casting process. The chemical composition, microstructure, and lead isotope ratio of Poong-Tag excavated from Wanggyeong site, Gyeongju can be used as fundamental data to compare with other Poong-Tag of different regions and periods.

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A Study on the Tendency of Standardization Related to Universal Design (유니버설 디자인 관련 표준화 동향에 관한 연구)

  • Lee, Ho-Soong
    • Archives of design research
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    • v.18 no.1 s.59
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    • pp.175-184
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    • 2005
  • With the rapid progress of the aging society in Korea, the silver generation is emerging as another class of users in the new population structure. This is a social issue to be dealt with, and the effect of such a change is being observed dearly in the design area. In addition, there are increasing demands for consideration of minor groups of users including the elderly, the disabled, the left-handed, children and pregnant women and nursing mothers, who have been treated as the weak. Such a human-centered idea may be the manifestation of the recovery of humanity and the self-realization of human beings through experiences and reflections of the industrial society of the past. The present study examined the tendency of design standardization centering on universal design, which has emerged in response to user-centered social needs, and suggested general considerations for the necessity of introducing such standards. These days the meanings of standardization are not limited to quality, performance, safety and economic aspect. Standardization is required to consider the diversity and the welfare of human beings. In addition, one of the important functions of standardization is to provide designers with important clues and guidelines for designing. In reality, however, standardization has been rejected by the circle of design for the reason that it deters free creation, so research on the introduction of standardization has been at standstill. As ISO/IEC Guide71 was published in November 2001, based on which, the Korea Standards Association established KS A ISO/IEC Guide71 without changing its contents. In companies' manufacturing activities, the progress of standardization in connection to universal design is growing more important. However, usefulness and interchangeability for the absolute majority resulting from standardization are incomparable. Lastly, the realization of universal design requires human-centered design mind, based on users' experiences and needs, the characteristics of the human bodies and inconvenient elements rather than standards for the sake of standardization.

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Humor Elements Analysis of Pixar Short Films Based on Henri Bergson's Theory of the Comic (픽사 단편 애니메이션에서 나타나는 유머요인 분석: 앙리 베르그송의 희극론을 중심으로)

  • Kim, Yun-Jung
    • Cartoon and Animation Studies
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    • s.19
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    • pp.51-64
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    • 2010
  • Although there has been a significant technological and representational achievements in domestic animation industry since the beginning of the 21th century due to the high expectation and boost in production, domestic long and short film animations have been less favored compared to foreign animations because they are less entertaining. For small scale productions including students, it is easier to create short film animations due to small budget and short time frame. In addition, as shown in Pixar animation studios case, production of short film animations can lead to success in production of long film animations from better ideas and technology improvements. This research studies factors that contribute to entertainment and humor of short film animation by examining Pixar's short film animations based on Henri Bergson's comedy factors, which are shape, movement, situation and language, and personality. The most noticeable fact is that the humor by situation is found in all short films. Comedy aspect shown in the form of character's internal characteristic is something that has to be considered from the beginning of character design. Contribution of language is minor compared to movement or gesture, which are more often used to cause humor. Finally, character's personality has to be clear and decided beforehand in order to create comedy situations. After studying various short film animations, I found out that the more successfully humorous an animation is, the more it uses various combinations of the above mentioned comedy factors. By fully analyzing and adopting commercially and artistically successful Pixar's short film animations as the benchmark, planning and production of domestic short film animations can perform entertainment role both domestically and globally.

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Applied Mineralogy for the Conservation of Dinosaur Tracks in the Goseong Interchange Area (35번 고속도로 고성 교차로 지역 공룡발자국의 보존을 위한 응용광물학적 연구)

  • Jeong Gi Young;Kim Soo Jin
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.3
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    • pp.189-199
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    • 2004
  • Cretaceous sedimentary rocks bearing dinosaur tracks in the Goseong interchange area were studied for their conservation and public display in the aspect of applied mineralogy. Black clay layers alternate with silt layers in the sedimentary rocks. The verical and horizontal fissures are commonly filled with calcite veinlets, supergenetic iron and manganese oxides. The rocks are composed of quartz, albite, K-feldspar, calcite, chlorite, illite, muscovite, and biotite, with minor apatite and rutile. Silt layers are relatively rich in calcite and albite, whereas clay layers are abundant in quartz, illite, and chlorite. Al, Fe, Mg, K, Ti, and P are enriched in the clay layers, while Ca, Na, and Mn in silt. Most of trace elements including V, Cr, Co, Ni, Cs, Zr, REE, Th, and U are enriched in clay layers. Inorganic carbon are present in silt layers as calcite, while organic carbon in black clay layers. The black clay layers were partly altered to yellow clay layers along the fissures, simultaneously with the decrease of organic carbon. Selective exfoliation of clay-rich black and yellow clay layers, calcite matrix of silt layers and calcite infillings of fissures are estimated as the major weakness potentially promoting chemical and physical degradation of the track-bearing rock specimens.

Creep Deformation Behaviors of Tin Pest Resistant Solder Alloys (Tin Pest 방지 솔더합금의 크리프 특성)

  • Kim S. B.;Yu Jin;Sohn Y. C.
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.1 s.34
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    • pp.47-52
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    • 2005
  • Worldwide movement for prohibition of Pb usage drives imminent implementation of Pb-free solders in microelectronic packaging industry. Reliability information of Pb-free solders has not been completely constructed yet. One of the potential reliability concerns of Pb-free solders is allotropic transformation of Sn known as tin pest. Volume increase during the formation of tin pest could deteriorate the reliability of solder joints. It was also reported that the addition of soluble elements (i.e. Pb, Bi, and Sb) into Sn can effectively suppress the tin pest. However, the mechanical properties of the tin pest resistant alloys have not been studied in detail. In this study, lap shear creep test was conducted with Sn and Sn-0.7Cu based solder alloys doped with minor amount of Bi or Sb. Shear strain rates of the alloy were generally higher than those of Sn-3.5Ag based alloys. Rupture strains and corresponding Monkman- Grant products were largest for Sn-0.5Bi alloy and smallest for Sn-0.7Cu-0.5Sb alloy. Rupture surface Sn-0.5Bi alloy showed highly elongated $\beta$-Sn globules necked to rupture by shear stresses, while elongation of $\beta$-Sn globules of Sn-0.7Cu-0.5Sb alloy was relatively smaller.

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Mineralogical Characteristics of Calcite observed in the KAERI Underground Research Tunnel (고준위폐기물 지하처분연구시설(KURT)에서 관찰되는 방해석의 광물학적 특징)

  • Lee, Seung-Yeop;Baik, Min-Hoon;Cho, Won-Jin
    • Journal of the Mineralogical Society of Korea
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    • v.19 no.4 s.50
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    • pp.239-246
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    • 2006
  • KAERI Underground Research Tunnel (KURT) was recently constructed through the site investigation from the yea. of 2003 at KAERI site, Dukjin-dong, Yuseong-gu, Daejeon city. The geo-logic setting of the site has been slightly metamorphosed. There are small fractures developed in the rock and several kinds of secondary filling minerals exist in the fractures. We examined mineralogical characteristics of fracture-filling calcite, which is not only largely distributed, but also can significantly affect the radionuclides migration. The calcite is found along fractures like other secondary minerals, forming thick veins in part. Most calcite-filled fractures contain quartz, iron oxides, and dolomite as minor minerals. The calcite crystals show an characteristic appearance with an uniformly oriented growth, coated with goethite on the edge and the etch-pit sites of their surface. Some calcite crystals have been newly formed by the precipitation of elements dissolved from the tunnel shotcrete wall, and their morphology changed according to the chemistry and flow of groundwater. The calcite can modify the groundwater chemistry and significantly affect the sorption behavior of radionuclides. The characteristic crystal structure and surface morphology of the calcite examined in the KURT site will be used as important basic data for the radionuclide migration experiment in the future.

Chemical and Mineralogical Characteristics of White Stones Excavated from Archaeological Sites (유적지 출토 백색 암석의 광물화학적 특성)

  • Han, Min-Su;Cho, Nam-Chul;Kim, Woo-Hyun;Choi, Kyung-Yong
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.3
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    • pp.199-206
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    • 2009
  • The aim of this study is to investigate the relations among each white stone and their characteristics through the chemical and mineralogical analysis of them excavated from around some kilns in archaeological sites. Moreover it was intended to infer the function of kilns. Nine white stones were chosen from three different archaeological sites, the each name of which is Sanyang-ri, Youngdu-ri and Gwangdae-ri in Chungcheongnam-do. In the mineralogical characteristics of thin section, eight stones containing calcite are altered and recrystallized by metasomatism and hydrothermal process, and Calcites, major component minerals of limestone, were identified by the analysis of XRD. On the basis of this result, we can infer the stones to be classified into limestone groups. One the other hand, research revealed that one of the white stones was a white pelitic stone composed of quartz, microcline and muscovite. In the analysis of chemical composition, except for the white pelitic stone eight stones are mainly composed of CaO which is major component of Calcite. Besides, as a results of correlation analysis by using a chemical compositions of major and minor elements in white stones, little did each archaeological site have the relativity. In conclusion, each archaeological site was estimated that they would use a limestone ores extracted from different deposits, and there is a high possibility that the function of these kilns is to produce quicklime.