• 천문학회보
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• 제36권2호
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• pp.147.1-147.1
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• 2011

We investigate the chemical differentiation in F, G, K type stars with and without planets to extend the work by Kang et al. (2011) to various spectral types. Since the primordial chemical composition has been preserved in the stellar atmosphere, stellar metallicity can provide the information on the primordial material, which is the potential building block of planets. Therefore, we can explore the favored conditions for planet formation through the comparison of chemical compositions between planet-host stars (PHSs) and stars without planets. In this work, we analyze 19 F, G, and K type stars. In each spectrum, we measure equivalent widths (EWs) of Fe, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, and Ni using TAME (Tools for Automatic Measurement of Equivalent width). The abundances of these species can be derived with the measured EWs and MOOG code (Sneden 1973). Like results by precedent studies, we find that planet-host stars have abundances higher than stars without planets. The typical difference in the abundances of Na, Mn, Co and Ni is $0.4{\pm}0.2dex$. In addition, as found in Kang et al. (2011), Mn is the most different element between PHSs and comparison stars.

• 천문학회보
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• 제36권1호
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• pp.27.1-27.1
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• 2011

We obtained the spectra of 93 Planet host stars and 73 normal field stars in F, G, K type using BOES at BOAO. We measured the equivalent width of Fe and 25 elements lines using the automatic EW measurement program, TAME(Tools for Automatic Measurement of Equivalent-widths) and estimated the elemental abundances by synth and abfind driver of MOOG code. Since the absence of planets in the normal field stars cannot be "completely" proved, this work focused on the chemical abundances and planet properties of planet host stars, which have the massive planets close to the parent star relatively. We carried out an investigation for the difference of abundances between stars with "Hot Jupiter" and normal field stars with no known planets. We examined the chemical composition of 25 elements, such as C, N, O, S, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu by EW measurements, and the S abundances were estimated using synthetic spectrum. We have found that [Mg/Fe] and [Al/Fe] for planet host stars have lower limit comparing with those of comparison stars, and [Ca/Fe] of host star with Neptunian planets is relatively lower than the other host stars with massive planets. We have performed the Kolmogorov-Smirnov test, and examined the ratio of planet host stars to all stars for each bin of [X/H]. As a result, we noted that the O, Si, and Ca abfor undances are strongly related with the presence of planets.

• 자원환경지질
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• 제42권3호
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• pp.247-259
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• 2009

영남육괴의 북동부에 분포하는 변성퇴적암류의 전암 붕소를 분석했다. 연구지역의 변성퇴적암류는 광물 조합에 따라 규선석대와 석류석대로 나누어지며, Ti-흑운모 지온계를 이용한 4-6 kbar 사이의 변성온도는 각각 553-687$^{\circ}C$와 582-722$^{\circ}C$이다. 붕소의 전함량은 흑연이 다량 포함된 석류석대의 한개 시료(89.95 ppm B)를 제외하고 규선석대(9.60- 189.18 ppm B)에서 석류석대(2.63-15.97 ppm B)로 높은 온도를 지시하는 지역에서 상대적으로 적은 함량을 갖는다. 붕소와 양의 상관관계를 이루는 $Al_2O_3$, MgO, $Fe_2O_3$, $Fe_2O_3$, $K_2O$, Li, Ba, Sc, Co, Cr, Rb, Cs는 전기석을 구성하는 주원소로 전기석의 비율이 증가할수록 붕소의 함량이 증가한다는 것을 부분적으로 지시한다. 광물의 모드비와 붕소의 전함량 비교는 붕소를 조절하는 주된 광물이 전기석 및 흑연임을 지시한다. 흑운모 화강편마암의 전암 붕소 함량(2.62-12.2 ppm B)은 전반적으로 변성퇴적암보다 붕소함량이 낮거나 비슷하며 변성 압력-온도 조건과는 관련성이 없다.

• Journal of the korean society of oceanography
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• 제38권1호
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• pp.17-23
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• 2003

We report the distribution of $^{210}$ Pb and various metallic elements (Al, Fe, Mg, Ca, Ti, Mn, Sr, Ba, Zn, V, Cr, Zr, Ni, Cu, and Y) in the sediment cores from six shellfish-farming bays in the South Sea of Korea. The $^{210Pb}$ inventories in Deukryang, Gwangyang, and Goseong Bay cores were comparable to those expected from the known fallout input. However, the $^{210}$ Pb inventories were two times higher in Jinju, Gangjin, and Hansan-Koeje Bay cores, suggesting an important role of other sources such as fluvial inputs. Based on the enrichment factor analyses, non-detrital fractions of all the measured elements were found to be insignificant. The Mn was highly enriched only in the surface sediments of the Jinju and Goseong Bay, which implies that the surface-sediment environment of these bays is efficiently oxidizing Mn remobilized from either pore waters or bottom seawaters. These data set provides the sources of heavy metal in sediment around shellfish farms and the current level of metallic elements for the future monitoring.

• 약학회지
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• 제36권3호
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• pp.199-204
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• 1992

The trace elements in animal feed were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS, VG-PlasmaQuad Co.) to find possible sources of heavy metals accumulation in rat organ. The study about spectral interference was performed by analysis of a background spectrum of ICP-MS. Recovery test using standard of Cd and Se (100 ppb) was found to be better than 90%. Twenty elements (Ca, Fe, Mg, Ti, Cr, Ni, Cu, Zn, Ba, Al, Mn, Pb, B, Ce, Bi, U, V, Cd, and W)are determined.

• 천문학회보
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• 제35권2호
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• pp.78.1-78.1
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• 2010

We obtained the spectra of 93 Planet host stars and 73 normal field stars in F, G, K type using BOES at BOAO. We measured the equivalent width of Fe and 13 elements lines using the automatic EW measurement program, TAME(Tools for Automatic Measurement of Equivalent-widths) and estimated the abundances by synth and abfind driver of MOOG code. Since the absence of planets in the normal field stars cannot be "completely" proved, this work focused on the chemical abundances and planet properties of planet host stars, which have the massive planets close to the parent star relatively. We carried out an investigation for the difference of abundances between stars with "Hot Jupiter" and normal field stars with no known planets. We examined the chemical composition of 12 elements, such as Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, and Ni by EW measurements, and the S abundances were estimated using synthetic spectrum.

• 한국자원식물학회지
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• 제3권2호
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• pp.115-121
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• 1990

In view of the results to have measured metallic elements which is included in 40 sorts of herb medicines and surveyed their distribution, ninekinds of metals including Co, Ce, Ga, 71, Cd, As, Sbr Bu. Pb, are never orlittle included in almost herb medicines. Other twenty four sorts of ele-ments (Mo, Sc, Be, V, Ni, Su, Se, Ba, Cr, Su, Ti, B, Li, Mg, Ca, Sr, Mnl Fe,Cu, Zn. p, Al, Na, K) are metals that are included in large quentities incomparison with others. Selagirellae Radix contains is kinds of metallicelements more then other herb medicines does. The content of elements ofinorganic metal differs greatly according to the part of herb medicines .

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.309-310
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• 2005

Some minor elements(Al, B, Ba, Ca, Cd, Co, Cr, Cu, Gd, Mg, Mn, Mo, Nd, Ni, P, Pb, Si, Sn, Sr, Ti, V, Yb, Zn and Zr) in iron compounds such as the S/G sludge of a power plant were separated from iron by anionic and cationic exchange methods. If a ICP-AES or AAS determination follows this method, minor elements of more than 2 or 20 ppm of Fe can be determined with an error less than 20% except Sn and Mo. Alkaline elements were excluded from this study since they can be easily recovered from an anionic exchange. Application to real sludge samples is ongoing.

• Advances in concrete construction
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• 제3권2호
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• pp.145-159
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• 2015

The evolution of nanotechnology provides materials with advance properties. It's a fast growing area of research to introduce the oxide nanoparticles into the cement pastes to improve their performance. The purpose of this paper is to review the effects of oxide nanoparticles (such as $SiO_2$, $TiO_2$, $Fe_2O_3$, $ZnO_2$, $Cr_2O_3$ and $Al_2O_3$) on both of hardened concrete properties (i.e., compressive strength, split tensile strength and flexural strength, water permeability, Abrasion resistance and pore structure of concrete) and fresh concrete properties (i.e., workability and setting time). Graphical representations of all these parameters were presented to facilitate the comparison of the effect of oxide nanoparticles on concrete processing. The paper also introduces some discussion about future work in this direction by identifying some open research area.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.76-76
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• 2015

PVD에 의한 증착 대상 물질인 Ti, AlSi, Cr 및 각각의 타겟 전류, 바이어스, 압력 조건 들을 설계하여 적용시켰으며 PECVD와 CBC 코팅을 조합하여 발생되는 새로운 나노 멀티박막의 특성을 본 연구에서는 시험분석 및 평가하였다. 코팅층 깊이에 따른 조성 변화는 XPS를 이용하였으며 미세조직 및 표면 상태는 FE-SEM을 이용한 정밀 분석을 실시하였다. 또한, 박막의 경도는 나노인덴터를 이용하여 박막 자체의 경도만을 분석하였다. 한편, Pin-on-disk 방식의 마모시험기를 이용하여 표면조도와 상대재의 처리 상태에 따른 마찰계수를 시험 평가하였다.