• Title/Summary/Keyword: elemental analysis

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Synthesis and Characterization of A Carbosilane Dendrimer Containing Allylic End Groups

  • 김정균;박은미;강은주
    • Bulletin of the Korean Chemical Society
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    • v.17 no.7
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    • pp.592-595
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    • 1996
  • A silane dendrimer with 48 allylic end groups has been synthesized in excellent yield, via repetitive alkenylation-hydrosilation cycles. Starting with hexaallylethylenedisilane ((CH2=CHCH2)3SiCH2)2 as the core molecule (G0), a succession of alternate platinum catalyzed hydrosilation (Pt/C, 10% platinum content on active carbon) of all allyl groups with methyldichlorosilane and the allylation of all SiCl2 groups with allylmagnesium bromide in THF provided 3rd generation (G3) as carbosilane dendrimer. All the generations of dendrimer have been characterized by 1H and 13C NMR spectroscopy as well as elemental analysis.

Depth Resolution Analysis of Axially Distributed Stereo Camera Systems under Fixed Constrained Resources

  • Cho, Myungjin;Shin, Donghak
    • Journal of the Optical Society of Korea
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    • v.17 no.6
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    • pp.500-505
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    • 2013
  • In this paper, we propose a novel framework to evaluate the depth resolution of axially distributed stereo sensing (ADSS) under fixed resource constraints. The proposed framework can evaluate the performance of ADSS systems based on various sensing parameters such as the number of cameras, the number of total pixels, pixel size and so on. The Monte Carlo simulations for the proposed framework are performed and the evaluation results are presented.

Synthesis and structure of $[Cp^*Rh({\eta}^6-2,6-diisopropylaniline)](OTF)_2$

  • 백지영;한원석;이순원
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2002.11a
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    • pp.29-29
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    • 2002
  • Reaction of [$Cp^*Rh(NO_3)OTf$] (1) with 2,6-diisopropylaniline under argon led to the formation of $[Cp^*Rh({\eta}^6-2,6-diisopropylaniline)](OTF)_2$, (2). Compound 2 was characterized by NMR, IR, elemental analysis, and X-ray diffraction. Crystallrographc data for 2: orthorhombic, space group $Cmc2_1$, $a=19.850(16){\AA}$, $b=9.870(8){\AA}$, $c=15.774(13){\AA}$, Z = 4, $R(wR_2)=0.0362(0.0938)$.

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ACTIVATION ANALYSIS OF ENVIRONMENTAL SAMPLES USING THE MT-25 MICROTRON OF THE FLNR

  • Maslov, O.D.;Belov, A.G.;Starodub, G.Ya.;Dmitriev, S.N.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.815-820
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    • 1995
  • Instrumental neutron and gamma activation analysis of coal and combustion products, determination of platinum content in natural samples by radiochemical gamma activation analysis and high-sensitive track method of thorium determination has been studied with the use of the MT-25 microtron.The optimal conditions for complete elemental analysis of coal and combustion products, isolation and determination of platinum and thorium are recommended.

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Effect of SO2 on the Simultaneous Removal of Mercury and NOx over CuCl2-loaded V2O5-WO3/TiO2 SCR Catalysts (CuCl2가 담지된 V2O5-WO3/TiO2 SCR 촉매에 의한 수은 및 NOx 동시 제거에서 SO2의 영향)

  • Ham, Sung-Won
    • Clean Technology
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    • v.28 no.1
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    • pp.38-45
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    • 2022
  • CuCl2-loaded V2O5-WO3/TiO2 catalyst showed excellent activity in the catalytic oxidation of elemental mercury to oxidized mercury even under SCR condition in the presence of NH3, which is well known to significantly inhibit the oxidation activity of elemental mercury by HCl. Moreover, it was confirmed that, when SO2 was present in the reaction gas together with HCl, excellent elemental mercury oxidation activity was maintained even though CuCl2 supported on the catalyst surface was converted to CuSO4. This is thought to be because not only HCl but also the SO4 component generated on the catalyst surface promotes the oxidation of elemental mercury. However, in the presence of SO2, the total mercury balance before and after the catalytic reaction was not matched, especially as the concentration of SO2 increased. In order to understand the cause of this, further studies are needed to investigate the effect of SO2 in the SnCl2 aqueous solution employed for mercury species analysis and the effect of sulfate ions generated on elemental mercury oxidation. It was confirmed that SO2 also promotes NOx removal activity, which is thought to be because the increase in acid sites by SO4 generated on the catalyst surface by SO2 facilitates NH3 adsorption. The composition change and structure of the components present on the catalyst surface under various reaction conditions were measured by XRD and XRF. These measurement results were presented as a rational explanation for the results that SO2 enhances the oxidation activity of elemental mercury and the NOx removal activity in this catalyst system.

A Study on the Behavior of Welded Connections (용접 연결부의 거동에 관한 연구)

  • 안주옥;윤영만
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.145-151
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    • 1994
  • Welded connections have been designed on basis of allowable stresses, wherein the response to loading is assumed to be totally elastic. This is the vector analysis method, which resolves the stresses determined from the direct stress formula and the torsion formula into a vector combination to obtain a solution. It has been known that this method gives conservative answers and typically a very high factor of safety. An analytical method based on the Instantaneous Center of Rotation has been developed which predicts the ultimate strength of an eccentically loaded fillet welded connection. The method of Instantaneous Center of Rotation results in weld resistance capacities greater than the vector analysis method, by recognizing the variation in fillet weld strength with respect to the direction of the applied loading and actual load-deformation response of elemental fillet welds. The procedure of numerical analysis is iterative and complex. The relations between vector analysis method and the method of Instantaneous Center of Rotation on eccentrical distance subjected to variation of load direction are presented in this paper. Considering of the effects on configuration of weld groups, the method of Instantaneous Center of Rotation are provided a more exact results of the numerical analysis.

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Elemental Correlations of Chemical Compositions in Co-rich Mn-crusts of the Republic of Marshall Islands (마샬공화국 고코발트망간각 화학조성의 원소 상관관계)

  • 황의덕;장세원;김두영
    • Journal of the Mineralogical Society of Korea
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    • v.12 no.2
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    • pp.77-90
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    • 1999
  • Characteristics and variations of chemical compositions in Co-rich crusts occurred in the EEZ of the Republic of Marshall Islands were reviewed. Correlation coefficient analysis, hierarchical cluster analysis, and Q-mode factor analysis for 62 samples were done in this study. All data were selected and gathered from the open file report of the cooperative cruise done by United States Geological Survey with Scripps Institute of Oceanography, University of Hawaii or Korea Ocean Research Development Institute. The average of crust thickness. Co content, and Ni content of 62 samples from the 21 seamounts were 30mm, 0.58 wt% and 0.40%, respectively. The mineral phases and associated elements assigned by correlation coefficients, cluster analysis and Q-mode factor analysis are following four. 1) CFA: P, Ca, CO2, Y, Sr: 2) Mn-oxide mineral: As, Mn, Co, Na: 3) Al-silicate mineral: Pd,Si, Al, Cu, Fe: 4) PGE-bearing mineral: Rh, Pt, Ir.

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A Comparative Study on Effect of Finite Element in Static Analysis of Sheet Metal Forming (판재성형 정적해석에서 유한요소의 영향에 대한 비교연구)

  • 윤용석;박종진
    • Transactions of Materials Processing
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    • v.9 no.1
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    • pp.17-26
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    • 2000
  • A series of parametric study was performed for the investigation on the influence of analysis parameters to the solution behavior in the elastic-plastic-static analysis of several sheet metal forming processes, such as deflection by a point force under plane strain and axisymmetric conditions, plane strain bending by a punch, axisymmetric stretching by a punch, axisymmetric bulging by hydraulic pressure, and axisymmetric deep drawing by a punch. The parameters considered are kind of element, number of elements, integration scheme for elemental equation and friction coefficient. Results obtained for different selections of those parameters were compared with each other, experimental measurements and analytical solution.

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Isotopic Analysis of NUSIMEP-6 Uranium Particles using SEM-TIMS

  • Park, Jong-Ho;Park, Sujin;Song, Kyuseok
    • Mass Spectrometry Letters
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    • v.4 no.3
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    • pp.51-54
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    • 2013
  • Isotopic analysis using thermal ionization mass spectrometry coupled with scanning electron microscopy (SEM-TIMS) was performed to determine the isotopic ratios of uranium contained in micro-particles in the 6th Nuclear Signatures Interlaboratory Measurement Evaluation Programme (NUSIMEP-6) sample. Elemental analysis by energy dispersive X-ray spectroscopy (EDS) was conducted on uranium-bearing mirco-particles, which were transferred to rhenium filaments for TIMS loading using a micromanipulation system in a SEM. A multi-ion-counter system was utilized to detect the ion signals of the four isotopes of uranium simultaneously. The isotope ratios of uranium corrected by bracketing using a reference material showed excellent agreement with the certified values. The measurement accuracy for $n(^{234}U)/n(^{238}U)$ and (b) $n(^{235}U)/n(^{238}U)$ was 10% and 1%, respectively, which met the requirements for qalification for the NetWork of Analytical Laboratories (NWAL).

Development of a human reliability analysis (HRA) guide for qualitative analysis with emphasis on narratives and models for tasks in extreme conditions

  • Kirimoto, Yukihiro;Hirotsu, Yuko;Nonose, Kohei;Sasou, Kunihide
    • Nuclear Engineering and Technology
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    • v.53 no.2
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    • pp.376-385
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    • 2021
  • Probabilistic risk assessment (PRA) has improved its elemental technologies used for assessing external events since the Fukushima Daiichi Nuclear Power Station Accident in 2011. HRA needs to be improved for analyzing tasks performed under extreme conditions (e.g., different actors responding to external events or performing operations using portable mitigation equipment). To make these improvements, it is essential to understand plant-specific and scenario-specific conditions that affect human performance. The Nuclear Risk Research Center (NRRC) of the Central Research Institute of Electric Power Industry (CRIEPI) has developed an HRA guide that compiles qualitative analysis methods for collecting plant-specific and scenario-specific conditions that affect human performance into "narratives," reflecting the latest research trends, and models for analysis of tasks under extreme conditions.