1,721,200 research outputs found
Thermodynamics and transport of high-density hydrogen plasma
No full textThe thermodynamic properties and transport coefficients of non-ideal, high-density hydrogen
plasma have been investigated, accounting for quantum effects due to the change in the energy
spectrum of atomic hydrogen when the the electron-proton interaction is considered embedded
in the surrounding particles. High-density conditions have been simulated assuming a simple
confined-atom model or atomic hydrogen subject to a screened Coulomb potential.
The ionization equilibrium is affected by the pressure
ionization phenomenon [1, 2]. In the case of Debye
plasma the influence of the plasma leads to a lowering
of the ionization energy and to an additional lowering
due to quantum effect on electronic levels. The electrical
conductivity (Fig. 1) exhibits a dependence on the total
(bound+free) electron density that mimics the ionization
degree profile, i.e. the minimum merging to the fully ionized
regime due to the Mott transition. The present results
have been compared with results in literature [3, 4], obtained
in the frame of different theories, finding significant
differences when the effect of the Debye screening
on atomic electronic levels is considered.
References
[1] D. Kremp, M., Schlanges, W. D. Kraeft, Quantum Statistic of Nonideal Plasmas in
Springer Series on Atomic, Optical and Plasma Physics 25 Springer, 2005.
[2] M. Capitelli, G. Colonna, A. D’Angola, Fundamental Aspects of Plasma Chemical
Physics: Thermodynamics, in Springer Series on Atomic, Optical, and Plasma Physics
66 Springer, 2012.
[3] M. Schlanges, D. Kremp, H. Keuer, Annalen der Physik 496, 54 (1984).
[4] H. Reinholz, R. Redmer, S. Nagel, Phys. Rev. E 52, 5368 (1995)
A Hierarchical Approach for Fast and Accurate Equilibrium Calculation
No full textIn the present paper an improved stoichiometric algorithm based on the successive single reaction equilibrium has been
described, avoiding the solution of large systems. The algorithm calculates the equilibrium composition adding automatically
suitable new reactions to improve the convergence. The algorithm has been tested for plasma composition calculation for a pure
nitrogen and air plasma mixtures. The algorithm proposed always converges and it is significantly faster than other hierarchical
algorithms
Picentia (Pontecagnano). b) Necropoli
No full textIl sottoscritto, Carmine Pellegrino, è autore della presentazione, con l’inquadramento topografico delle aree di necropoli da cui provengono le iscrizioni (pp. 296-297), e delle schede delle tombe e dei supporti vascolari, nonché della lettura delle epigrafi nn. 23-24 (p. 298), 25 (p. 300), 27-30 (pp. 303-306)
Tamburini (P.), Un abitato villanoviano peripalustre ; il "Gran Carro " sul lago di Bolsena (1959-1985). Prefazione di G. Colonna, 1995
No full textJannot Jean-René. Tamburini (P.), Un abitato villanoviano peripalustre ; il "Gran Carro " sul lago di Bolsena (1959-1985). Prefazione di G. Colonna, 1995. In: Revue des Études Anciennes. Tome 101, 1999, n°3-4. pp. 589-591
EquilTheTA: Thermodynamic and Transport Properties of Complex Equilibrium Plasmas
No full textEquilTheTA (EQUILibrium for plasma THErmodynamics and Transport Applications) is a web-based software which calculates chemical equilibrium product concentrations from any set of reactants and determines thermodynamic and transport properties for the product mixture in wide temperature and pressure ranges. The program calculates chemical equilibrium by using a hierarchical approach, thermodynamic properties and transport coefficients starting from recent and accurate databases of atomic and molecular energy levels and collision integrals. In the calculations, Debye length and cut-off are consistently updated and virial corrections (up to third order) can be considered. Transport coefficients are calculated by using high order approximations of the Chapman-Enskog method
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Statistical thermodynamic description of H2 molecules in normal ortho/para mixture
No full textIn this paper, an expression for the internal partition function of normal hydrogen has
been obtained starting from the principles of classical statistical thermodynamics. The
calculated contribution applies to ideal gas properties. Particular attention has been
devoted to the entropy, which depends on the logarithm of the partition function.
Comparison between normal and equilibrium hydrogen together with theoretical and
experimental data available in literature has been discussed. Tables of the thermodynamic
properties of hydrogen and hydrogen ion are also reported
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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