The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Istvan Nagy - One of the best experts on this subject based on the ideXlab platform.
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Transport cross sections based on a screened interaction potential : Comparison of classical and quantum-mechanical results
Physical Review A, 2005Co-Authors: R. Vincent, J. I. Juaristi, Istvan NagyAbstract:Standard classical and quantum-mechanical methods are used to characterize the momentum-transfer cross section needed in energy-loss calculations and simulations for heavy, swift charges moving in an electron gas. By applying a well-known, finite-Range screened Coulombic potential energy to model the two-body collision, the quantitative Applicability Range of the classical cross section is investigated as a function of charge $(Z)$, screening length $(R)$, and scattering relative velocity $(v)$. The a posteriori condition $(Z∕R)∕{v}^{2}l1$, as an upper bound for heavy charges, is deduced for this Applicability Range from the comparative study performed.
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Transport cross sections based on a screened interaction potential: Comparison of classical and quantum-mechanical results
Physical Review A, 2005Co-Authors: R. Vincent, J. I. Juaristi, Istvan NagyAbstract:Standard classical and quantum-mechanical methods are used to characterize the momentum-transfer cross section needed in energy-loss calculations and simulations for heavy, swift charges moving in an electron gas. By applying a well-known, finite-Range screened Coulombic potential energy to model the two-body collision, the quantitative Applicability Range of the classical cross section is investigated as a function of charge (Z), screening length (R), and scattering relative velocity (v). The a posteriori condition (Z/R)/v2
Ya-pu Zhao - One of the best experts on this subject based on the ideXlab platform.
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Applicability Range of stoney s formula and modified formulas for a film substrate bilayer
Journal of Applied Physics, 2006Co-Authors: Yin Zhang, Ya-pu ZhaoAbstract:In addition to the layer thickness and effective Young’s modulus, the impact of the kinematic assumptions, interfacial condition, in-plane force, boundary conditions, and structure dimensions on the curvature of a film/substrate bilayer is examined. Different models for the analysis of the bilayer curvature are compared. It is demonstrated in our model that the assumption of a uniform curvature is valid only if there is no in-plane force. The effects of boundary conditions and structure dimensions, which are not (fully) included in previous models are shown to be significant. Three different approaches for deriving the curvature of a film/substrate bilayer are presented, compared, and analyzed. A more comprehensive study of the conditions regarding the Applicability of Stoney’s formula and modified formulas is presented.
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Applicability Range of Stoney’s formula and modified formulas for a film/substrate bilayer
Journal of Applied Physics, 2006Co-Authors: Yin Zhang, Ya-pu ZhaoAbstract:In addition to the layer thickness and effective Young’s modulus, the impact of the kinematic assumptions, interfacial condition, in-plane force, boundary conditions, and structure dimensions on the curvature of a film/substrate bilayer is examined. Different models for the analysis of the bilayer curvature are compared. It is demonstrated in our model that the assumption of a uniform curvature is valid only if there is no in-plane force. The effects of boundary conditions and structure dimensions, which are not (fully) included in previous models are shown to be significant. Three different approaches for deriving the curvature of a film/substrate bilayer are presented, compared, and analyzed. A more comprehensive study of the conditions regarding the Applicability of Stoney’s formula and modified formulas is presented.
Noreen J. Evans - One of the best experts on this subject based on the ideXlab platform.
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application of combined u th disequilibrium u pb and u th he zircon dating to tephrochronology
Quaternary Geochronology, 2017Co-Authors: Martin Danišík, István Dunkl, Daniel F Stockli, Axel K Schmitt, Oscar M Lovera, Noreen J. EvansAbstract:Abstract The combination of U-Th disequilibrium/U-Pb and (U-Th)/He dating of zircon (ZDD) has provided a relatively new radiometric approach suitable for dating Quaternary zircon-bearing volcanic and pyroclastic deposits. This approach permits the dating of zircon as young as ca. 2.5 ka and has huge potential for tephrochronology and other fields of Quaternary science. Its Applicability Range covers the critical time-window in Quaternary geochronology beyond the Range of 14 C and below the limit of routine Ar/Ar dating (i.e. between ca. 50 ka and 1.5 Ma). The combined U-Th disequilibrium/U-Pb and (U-Th)/He dating approach can also be applied to other actinide-rich minerals such as allanite or monazite. In In this review paper we summarize past developments and the current state of the ZDD method, explain the theoretical principles, and document the necessity of combining (U-Th)/He with U-Th-disequilibrium and/or U-Pb methods when dating young volcanic material. We then describe analytical procedures and highlight the advantages of the ZDD method. Finally, we present some examples that illustrate the efficacy of this method to derive reliable eruption ages for young tephras, and outline future directions in methodological development and application for this geochronological tool.
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Application of combined U-Th-disequilibrium/U-Pb and (U-Th)/He zircon dating to tephrochronology
Quaternary Geochronology, 2017Co-Authors: Martin Danišík, István Dunkl, Daniel F Stockli, Axel K Schmitt, Oscar M Lovera, Noreen J. EvansAbstract:Abstract The combination of U-Th disequilibrium/U-Pb and (U-Th)/He dating of zircon (ZDD) has provided a relatively new radiometric approach suitable for dating Quaternary zircon-bearing volcanic and pyroclastic deposits. This approach permits the dating of zircon as young as ca. 2.5 ka and has huge potential for tephrochronology and other fields of Quaternary science. Its Applicability Range covers the critical time-window in Quaternary geochronology beyond the Range of 14 C and below the limit of routine Ar/Ar dating (i.e. between ca. 50 ka and 1.5 Ma). The combined U-Th disequilibrium/U-Pb and (U-Th)/He dating approach can also be applied to other actinide-rich minerals such as allanite or monazite. In In this review paper we summarize past developments and the current state of the ZDD method, explain the theoretical principles, and document the necessity of combining (U-Th)/He with U-Th-disequilibrium and/or U-Pb methods when dating young volcanic material. We then describe analytical procedures and highlight the advantages of the ZDD method. Finally, we present some examples that illustrate the efficacy of this method to derive reliable eruption ages for young tephras, and outline future directions in methodological development and application for this geochronological tool.
Francisco Fernandez-lima - One of the best experts on this subject based on the ideXlab platform.
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Coupling trapped ion mobility spectrometry to mass spectrometry: trapped ion mobility spectrometry-time-of-flight mass spectrometry versus trapped ion mobility spectrometry-Fourier transform ion cyclotron resonance mass spectrometry.
Rapid Communications in Mass Spectrometry, 2018Co-Authors: Lilian V. Tose, Paolo Benigni, Dennys Leyva, Abigail Sundberg, Cesar E. Ramirez, Mark E. Ridgeway, Melvin A. Park, Rudolf Jaffé, Wanderson Romao, Francisco Fernandez-limaAbstract:RATIONALE: There is a need for fast, post-ionization separation during the analysis of complex mixtures. In this study, we evaluate the use of a high-resolution mobility analyzer with high-resolution and ultrahigh-resolution mass spectrometry for unsupervised molecular feature detection. Goals include the study of the reproducibility of trapped ion mobility spectrometry (TIMS) across platforms, Applicability Range, and potential challenges during routine analysis. METHODS: A TIMS analyzer was coupled to time-of-flight mass spectrometry (TOF MS) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) instruments for the analysis of singly charged species in the m/z 150-800 Range of a complex mixture (Suwannee River Fulvic Acid Standard). Molecular features were detected using an unsupervised algorithm based on chemical formula and IMS profiles. RESULTS: TIMS-TOF MS and TIMS-FT-ICR MS analysis provided 4950 and 7760 m/z signals, 1430 and 3050 formulas using the general Cx Hy N0-3 O0-19 S0-1 composition, and 7600 and 22 350 [m/z; chemical formula; K; CCS] features, respectively. CONCLUSIONS: TIMS coupled to TOF MS and FT-ICR MS showed similar performance and high reproducibility. For the analysis of complex mixtures, both platforms were able to capture the major trends and characteristics; however, as the chemical complexity at the level of nominal mass increases with m/z (m/z >300-350), only TIMS-FT-ICR MS was able to report the lower abundance compositional trends.
R. Vincent - One of the best experts on this subject based on the ideXlab platform.
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Transport cross sections based on a screened interaction potential : Comparison of classical and quantum-mechanical results
Physical Review A, 2005Co-Authors: R. Vincent, J. I. Juaristi, Istvan NagyAbstract:Standard classical and quantum-mechanical methods are used to characterize the momentum-transfer cross section needed in energy-loss calculations and simulations for heavy, swift charges moving in an electron gas. By applying a well-known, finite-Range screened Coulombic potential energy to model the two-body collision, the quantitative Applicability Range of the classical cross section is investigated as a function of charge $(Z)$, screening length $(R)$, and scattering relative velocity $(v)$. The a posteriori condition $(Z∕R)∕{v}^{2}l1$, as an upper bound for heavy charges, is deduced for this Applicability Range from the comparative study performed.
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Transport cross sections based on a screened interaction potential: Comparison of classical and quantum-mechanical results
Physical Review A, 2005Co-Authors: R. Vincent, J. I. Juaristi, Istvan NagyAbstract:Standard classical and quantum-mechanical methods are used to characterize the momentum-transfer cross section needed in energy-loss calculations and simulations for heavy, swift charges moving in an electron gas. By applying a well-known, finite-Range screened Coulombic potential energy to model the two-body collision, the quantitative Applicability Range of the classical cross section is investigated as a function of charge (Z), screening length (R), and scattering relative velocity (v). The a posteriori condition (Z/R)/v2