Atomic Ionization Potentials Derived from Theoretical Calculations

1975 ◽  
Vol 53 (21) ◽  
pp. 2415-2420 ◽  
Author(s):  
Serafin Fraga ◽  
K. M. S. Saxena ◽  
Jacek Karwowski ◽  
Brian Bray
Keyword(s):  
Experimental Data ◽  
Predictive Value ◽  
Theoretical Calculations ◽  
Ground States ◽  
Theoretical Method ◽  
Ionization Potentials ◽  
Hartree Fock ◽  
Atomic Ionization ◽  
Total Energies ◽  
Theoretical Results

A table of all the ionization potentials of the elements lithium through krypton is presented.These values have been derived from the theoretical results obtained, within the Hartree–Fock method and including all the relativistic corrections, for the total energies of the ground states. The characteristics of the theoretical method are briefly outlined.Comparison with available experimental data establishes the excellent predictive value of the theoretical results.

Influence of a Circumferential Exit Pressure Distortion on the Flow in an Impeller and Diffuser

1987 ◽  
Vol 109 (1) ◽  
pp. 48-54 ◽  
Author(s):  
M. Th. Sideris ◽  
R. A. Van den Braembussche
Keyword(s):  
Experimental Data ◽  
Static Pressure ◽  
Laser Doppler Anemometry ◽  
Theoretical Calculations ◽  
Interaction Model ◽  
Pressure Measurements ◽  
Velocity Measurements ◽  
Local Flow ◽  
Impeller Outlet ◽  
Theoretical Results

Detailed velocity measurements, using Laser Doppler Anemometry (LDA) and static pressure measurements in the vane/ess diffuser of a centrifugal compressor, are presented. They show the relation between the circumferential variation of the pressure and the local flow in the diffuser and at the impeller exit. Theoretical calculations using an impeller-diffuser interaction model have been made. A comparison between the theoretical results and experimental data allows an evaluation of the possibilities and shortcomings of such a calculation. It also illustrates the mechanisms by which the variation of the impeller outlet velocity is defined.

scholarly journals Collisions involving antiprotons and antihydrogen: an overview

2018 ◽  
Vol 376 (2116) ◽  
pp. 20170271 ◽  
Author(s):  
S. Jonsell
Keyword(s):  
Experimental Data ◽  
Theoretical Calculations ◽  
Research Project ◽  
Atoms And Molecules ◽  
Low Energies ◽  
Theoretical Results

I give an overview of experimental and theoretical results for antiproton and antihydrogen scattering with atoms and molecules (in particular H, He). At low energies ( 1 keV) there are practically no experimental data available. Instead I compare the results from different theoretical calculations, of various degrees of sophistication. At energies up to a few tens of eV, I focus on simple approximations that give reasonably accurate results, as these allow quick estimates of collision rates without embarking on a research project. This article is part of the Theo Murphy meeting issue ‘Antiproton physics in the ELENA era’.

Energy levels and spectral lines for Ge-like Zr, Nb and Tc ions

2020 ◽  
Author(s):  
Miao Wu ◽  
Zhen-Cen He
Keyword(s):  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
Experimental Values ◽  
Theoretical Results ◽  
Line Strengths

The energy levels, transition probabilities, oscillator strengths, line strengths and wavelengths of Ge-like Zr, Nb and Tc ions have been calculated using the multiconfiguration Dirac-Hartree-Fock method. The Breit interactions and quantum electrodynamics correction were taken into account. The calculated values of energy levels and wavelengths have been compared with other theoretical calculations and available experimental values, good agreements are achieved for most of the energy levels and wavelengths calculated. The number of energy levels and wavelengths considered is larger than that of any other theoretical calculations. And the transition probabilities, line strengths are also given where no other theoretical results and experimental values are available.

Hartree–Fock Ionization Potentials of Atoms

1973 ◽  
Vol 51 (19) ◽  
pp. 2063-2074 ◽  
Author(s):  
S. Fraga ◽  
K. M. S. Saxena ◽  
J. Karwowski
Keyword(s):  
Experimental Data ◽  
Ionization Potentials ◽  
Hartree Fock ◽  
Relativistic Corrections

Values of the first four ionization potentials have been calculated from Hartree–Fock energies, with and/or without the relativistic corrections, for the elements lithium to nobelium. The merit of the Hartree–Fock approximation, regarding the prediction of ionization potentials, is discussed by comparison to existing experimental data.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 18. EXPERIMENTAL CHECK OF THEORETICAL RESULTS FOR DIFFERENT HOLLOW RADIUSES AND BOTTOM-MOST PART THICKNESSES

2020 ◽  
Vol 0 (9) ◽  
pp. 16-23
Author(s):  
A. L. Vorontsov ◽  
◽  
I. A. Nikiforov ◽  
Keyword(s):  
Strain Hardening ◽  
Theoretical Calculations ◽  
High Accuracy ◽  
Geometric Parameters ◽  
Strength Characteristics ◽  
Experimental Check ◽  
Hardening Material ◽  
Direct Extrusion ◽  
Theoretical Results

The results of an experimental check of the obtained theoretical formulae allowing us to determine the most important parameters of extrusion cartridges with a counterpunch for different hollow radiuses and bottom-most part thicknesses are presented. Characteristics of used tools, geometric parameters of extrusion experiments, strength characteristics of deformed materials and lubricants are described in detail. Both strain-hardening material and strain-unhardening material were studied. Methodology of the theoretical calculations is demonstrated in detail. High accuracy of the obtained design formulae was confirmed.

scholarly journals THE METHOD OF INCREMENTS — A WAVEFUNCTION-BASED AB-INITIO CORRELATION METHOD FOR SOLIDS

2007 ◽  
Vol 21 (13n14) ◽  
pp. 2204-2214 ◽  
Author(s):  
BEATE PAULUS
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Ground State ◽  
Infinite System ◽  
Correlation Energy ◽  
Correlation Method ◽  
Many Body ◽  
Hartree Fock ◽  
The Many ◽  
Good Agreement

The method of increments is a wavefunction-based ab initio correlation method for solids, which explicitly calculates the many-body wavefunction of the system. After a Hartree-Fock treatment of the infinite system the correlation energy of the solid is expanded in terms of localised orbitals or of a group of localised orbitals. The method of increments has been applied to a great variety of materials with a band gap, but in this paper the extension to metals is described. The application to solid mercury is presented, where we achieve very good agreement of the calculated ground-state properties with the experimental data.

The Compliance of Solid, Wide-Faced Spur Gears

1990 ◽  
Vol 112 (4) ◽  
pp. 590-595 ◽  
Author(s):  
J. H. Steward
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Load Distribution ◽  
3D Model ◽  
Spur Gear ◽  
Point Load ◽  
Spur Gears ◽  
Line Load ◽  
Gear Teeth ◽  
Theoretical Results

In this paper, the requirements for an accurate 3D model of the tooth contact-line load distribution in real spur gears are summarized. The theoretical results (obtained by F.E.M.) for the point load compliance of wide-faced spur gear teeth are set out. These values compare well with experimental data obtained from tests on a large spur gear (18 mm module, 18 teeth).

scholarly journals IV. On the dynamical theory of incompressible viscous fluids and the determination of the criterion

1895 ◽  
Vol 186 ◽  
pp. 123-164 ◽  
Keyword(s):  
Singular Solution ◽  
Physical State ◽  
Theoretical Calculations ◽  
Equations Of Motion ◽  
Dynamical Theory ◽  
Viscous Fluids ◽  
Linear Functions ◽  
Incompressible Viscous Fluids ◽  
Theoretical Results

1. The equations of motion of viscous fluid (obtained by grafting on certain terms to the abstract equations of the Eulerian form so as to adapt these equations to the case of fluids subject to stresses depending in some hypothetical manner on the rates of distortion, which equations Navier seems to have first introduced in 1822, and which were much studied by Cauchy and Poisson) were finally shown by St. Venant and Sir Gabriel Stokes, in 1845, to involve no other assumption than that the stresses, other than that of pressure uniform in all directions, are linear functions of the rates of distortion, with a co-efficient depending on the physical state of the fluid. By obtaining a singular solution of these equations as applied to the case of pendulums in steady periodic motion, Sir G. Stokes was able to compare the theoretical results with the numerous experiments that had been recorded, with the result that the theoretical calculations agreed so closely with the experimental determinations as seemingly to prove the truth of the assumption involved. This was also the result of comparing the flow of water through uniform tubes with the flow calculated from a singular solution of the equations so long as the tubes were small and the velocities slow. On the other hand, these results, both theoretical and practical, were directly at variance with common experience as to the resistance encountered by larger bodies moving with higher velocities through water, or by water moving with greater velocities through larger tubes. This discrepancy Sir G. Stokes considered as probably resulting from eddies which rendered the actual motion other than that to which the singular solution referred and not as disproving the assumption.

Cross sections for d-3H neutron interactions with samarium isotopes

2016 ◽  
Vol 104 (8) ◽  
Author(s):  
Junhua Luo ◽  
Chunlei Wu ◽  
Li Jiang ◽  
Long He
Keyword(s):  
Experimental Data ◽  
Neutron Flux ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Nuclear Model ◽  
Activation Technique ◽  
Incident Neutron ◽  
Reaction Threshold ◽  
Talys 1.6 ◽  
The Cross

Abstract:The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the

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