Particle Number Dependence of Collective Properties of Nuclei in the Rare Earth Region

1974 ◽  
Vol 29 (8) ◽  
pp. 1131-1137
Author(s):  
H. Rafelski ◽  
B. Fink
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Rare Earth ◽  
Kinetic Energy ◽  
Particle Number ◽  
Interaction Model ◽  
Quantitative Agreement ◽  
Spin Model ◽  
Extended Version ◽  
Energy Surfaces

Within the framework of the pairing plus quadrupole interaction model and by using the technique of quasi spin formalism it is possible to determine the collective potential and kinetic energy surfaces as analytic functions of the particle number in the limit that single particle splittings are neglected. Pushing the quasi spin model in an extended version up to the 4th order in perturbation theory the stiffness and mass parameters of harmonic and anharmonic terms for Dy, Er, Yb, and Hf-isotopes have been calculated. The theoretical particle dependence of collective quantities shows a good qualitative and even quantitative agreement with experimental data and former calculations.

Kinetics of the Luminescence of Isoelectronic Rare-Earth Ions In III-V Semiconductors

1993 ◽  
Vol 301 ◽  
Author(s):  
H.J. Lozykowski
Keyword(s):  
Experimental Data ◽  
Energy Transfer ◽  
Rare Earth ◽  
Excited States ◽  
Quantitative Agreement ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Wide Range ◽  
Decay Times ◽  
Kinetics Of

ABSTRACTIn this work we have developed a model for the kinetics of the energy transfer from the host lattice to the localized core excited states of rare earth isoelectronic structured traps (REI-trap). We have derive a set of differential equations for semi-insulating semiconductor governing the kinetics of rare earth luminescence. The numerically simulated rise and decay times of luminescence show a good quantitative agreement with the experimental data obtained for InP:Yb, over a wide range of generation rates.

scholarly journals Epistemic values of quantity and variety of evidence in biological mechanism research

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Yin Chung Au
Keyword(s):  
Experimental Data ◽  
Causal Inference ◽  
Case Studies ◽  
Biological Mechanism ◽  
Data Generation ◽  
Extended Version ◽  
Epistemic Values ◽  
Difference Making ◽  
Mechanism Research ◽  
The Difference

AbstractThis paper proposes an extended version of the interventionist account for causal inference in the practical context of biological mechanism research. This paper studies the details of biological mechanism researchers’ practices of assessing the evidential legitimacy of experimental data, arguing why quantity and variety are two important criteria for this assessment. Because of the nature of biological mechanism research, the epistemic values of these two criteria result from the independence both between the causation of data generation and the causation in question and between different interventions, not techniques. The former independence ensures that the interventions in the causation in question are not affected by the causation that is responsible for data generation. The latter independence ensures the reliability of the final mechanisms not only in the empirical but also the formal aspects. This paper first explores how the researchers use quantity to check the effectiveness of interventions, where they at the same time determine the validity of the difference-making revealed by the results of interventions. Then, this paper draws a distinction between experimental interventions and experimental techniques, so that the reliability of mechanisms, as supported by the variety of evidence, can be safely ensured in the probabilistic sense. The latter process is where the researchers establish evidence of the mechanisms connecting the events of interest. By using case studies, this paper proposes to use ‘intervention’ as the fruitful connecting point of literature between evidence and mechanisms.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

Diffusion Coefficients of Interest for the Simulation of Heat Treatment in Rare-Earth Transition Metal Magnets

2012 ◽  
Vol 727-728 ◽  
pp. 163-168 ◽  
Author(s):  
Marcos Flavio de Campos
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Activation Energy ◽  
Rare Earth ◽  
Transition Metal ◽  
Impurity Atom ◽  
Diffusion Coefficients ◽  
Arrhenius Equation ◽  
Atom Diffusion ◽  
Essential Input

In the case of the modeling of sintering and heat treatments, the diffusion coefficients are an essential input. However, experimental data in the literature about diffusion coefficients for rare-earth transition metal intermetallics is scarce. In this study, the available data concerning diffusion coefficients relevant for rare-earth transition metal magnets are reviewed and commented. Some empirical rules are discussed, for example the activation energy is affected by the size of the diffusing impurity atom. Diffusion coefficients for Dy, Nd and Fe into Nd2Fe14B are given according an Arrhenius equation D=D0exp (-Q/RT). For Dy diffusion into Nd2Fe14B, Q 315 kJ/mol and D08 . 10-4m2/s.

Effect of Interaction Modeling in AFM-Based Nanomanipulation

2008 ◽  
Author(s):  
Fakhreddine Landolsi ◽  
Fathi H. Ghorbel ◽  
James B. Dabney
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Interaction Model ◽  
Collision Process ◽  
Visual Sensing ◽  
Proposed Model ◽  
Interaction Modeling

AFM-based nanomanipulation is very challenging because of the complex mechanics in tip-sample interactions and the limitations in AFM visual sensing capabilities. In the present paper, we investigate the modeling of AFM-based nanomanipulation emphasizing the effects of the relevant interactions at the nanoscale. The major contribution of the present work is the use of a combined DMT-JKR interaction model in order to describe the complete collision process between the AFM tip and the sample. The coupling between the interactions and the friction at the nanoscale is emphasized. The efficacy of the proposed model to reproduce experimental data is demonstrated via numerical simulations.

Study on the equivalent luminance of luminous fibers in photopic vision and scotopic vision

2017 ◽  
Vol 88 (10) ◽  
pp. 1157-1163 ◽  
Author(s):  
Yanhong Yan ◽  
Chengxia Liu ◽  
Xiaojun Ding
Keyword(s):  
Experimental Data ◽  
Rare Earth ◽  
Melt Spinning ◽  
Emission Spectra ◽  
Scotopic Vision ◽  
Photopic Vision ◽  
Earth Material ◽  
Long Afterglow ◽  
Polyamide Fiber ◽  
Spinning Process

Colored luminous fibers were prepared by a melt spinning process, adding colored pigments and long afterglow rare earth material into polyamide fiber. The colored luminous fibers had a variety of colors in photopic vision, and emitted colored light in mesopic vision and scotopic vision. Based on the experimental data of the emission spectra and the test luminance of the luminous fibers, the effect of the emissive colors of the luminous fibers on the equivalent luminance at different vision states was analyzed. The results showed that the effect of the emissive colors of white, red, yellow, and green luminous fibers on the equivalent luminance was not obvious in photopic and scotopic vision, but that of blue luminous fiber was obvious in photopic vision but not in scotopic vision.

scholarly journals A Three-Dimensional Magnetic Force SolutionBetween Axially-Polarized Permanent-Magnet Cylinders for Different Magnetic Arrangements

2020 ◽  
Vol 7 ◽  
Keyword(s):  
Experimental Data ◽  
Rare Earth ◽  
Field Strength ◽  
Permanent Magnet ◽  
Magnetic Force ◽  
Three Dimensional ◽  
Method Of Images ◽  
Field Equations ◽  
Rare Earth Magnet ◽  
Finite Sums

A three-dimensional field solution is presented foraxially polarized permanent magnet cylinders. The fieldcomponents are expressed in terms of finite sums of elementaryfunctions and are easily programmable. They can be used todetermine the operating point of rare-earth magnet cylinders.They are also useful for performing rapid parametriccalculations of field strength as a function of materialproperties and dimensions. The field components aredeveloped for different magnet arrangements by taking intoaccount the back iron. Also the method of images is used. Usingthe field equations, three-dimensional analytical expressionsare derived for computing the magnetic force between axiallypolarized permanent-magnet cylinders for different magneticarrangements. The field calculated results are in goodagreement with the experimental data.

Feshbach–Villars equation in a κ-Minkowski spacetime

2020 ◽  
Vol 35 (37) ◽  
pp. 2050307
Author(s):  
B. Hamil ◽  
M. Merad
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Deformation Parameter ◽  
Order Approximation ◽  
Minkowski Spacetime ◽  
Magnetic Interaction ◽  
Relativistic Limit ◽  
First Order ◽  
Klein Gordon ◽  
First Order Approximation

In this paper, by using the Dirac derivatives the Klein–Gordon (K-G) equation is determined in a [Formula: see text]-Minkowski spacetime. The dispersion relation and the first-order approximation case are deduced. The Feshbach–Villars (FV) equation is derived by applying the new linearization process to the time. We then study the effect of magnetic interaction on energies spectrum in a [Formula: see text]-Minkowski spacetime as an application, as a result we found that the energies spectrum are not symmetrical. We also study the case of hydrogen atom in non-relativistic limit by using perturbation theory. The upper bound of the [Formula: see text]-deformation parameter is evaluate, on the basis of the experimental data for [Formula: see text] transition frequency.

scholarly journals Search for η-mesic nuclei in the SRC/BM@N experiment at the Nuclotron

2019 ◽  
Vol 204 ◽  
pp. 09002
Author(s):  
S.V. Afanasiev ◽  
D.K. Dryablov ◽  
K. Michaličková
Keyword(s):  
Experimental Data ◽  
Kinetic Energy ◽  
Residual Nucleus ◽  
Bound State ◽  
Liquid Hydrogen ◽  
Pion Pair ◽  
Liquid Hydrogen Target ◽  
Hydrogen Target ◽  
Carbon Beam ◽  
Quasi Bound State

The SRC/BM@N experiment was carried out in the 55th run of the Nuclotron using a liquid hydrogen target and a carbon beam with a kinetic energy of about 3.1 GeV/n. We propose to analyze the experimental data to search for a quasi-bound state of η-meson and nucleons in the reaction 12C+p → η(A-1)+X → π+p+(A-2). To achieve this goal, it is necessary to identify the residual nucleus (A-2) and the proton-pion pair formed from η-nuclei decay.

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