53 research outputs found
Calculations for Extended Thermodynamics of dense gases up to whatever order and with all the symmetries
The 14 moments model for dense gases, introduced in the last years by Arima,
Taniguchi Ruggeri, Sugiyama, is here considered. They have found the closure of
the balance equations up to second order with respect to equilibrium; here the
closure is found up to whatever order with respect to equilibrium, but for a
more constrained system where more symmetry conditions are imposed and this in
agreement with the suggestion of the kinetic theory. The results, when
restricted at second order with respect to equilibrium, are the same of the
previously cited model but under the further restriction of full symmetries.Comment: arXiv admin note: substantial text overlap with arXiv:1410.405
Snyder-de Sitter model from two-time physics
We show that the symplectic structure of the Snyder model on a de Sitter
background can be derived from two-time physics in seven dimensions and propose
a Hamiltonian for a free particle consistent with the symmetries of the model.Comment: 9 page
An exact fluid model for relativistic electron beams: The many moments case
An interesting and satisfactory fluid model has been proposed in literature
for the the description of relativistic electron beams. It was obtained with 14
independent variables by imposing the entropy principle and the relativity
principle. Here the case is considered with an arbitrary number of independent
variables, still satisfying the above mentioned two principles; these lead to
conditions whose general solution is here found. We think that the results
satisfy also a certain ordering with respect to a smallness parameter
measuring the dispersion of the velocity about the mean; this
ordering generalizes that appearing in literature for the 14 moments case
Extended Thermodynamics for Dense Gases up to Whatever Order and with Only Some Symmetries
Extended Thermodynamics of dense gases is characterized by two hierarchies of field
equations, which allow one to overcome some restrictions on the generality of the previous
models. This idea has been introduced by Arima, Taniguchi, Ruggeri and Sugiyama. In~the
case of a 14-moment model, they have found the closure of the balance equations up to
second order with respect to equilibrium. Here, the closure is obtained up to whatever
order and imposing only the necessary symmetry conditions. It comes out that the first
non-symmetric parts of the higher order fluxes appear only at third order with respect to
equilibrium, even if Arima, Taniguchi, Ruggeri and Sugiyama found a non-symmetric part
proportional to an arbitrary constant also at first order with respect to equilibrium.
Consequently, this constant must be zero, as Arima, Taniguchi, Ruggeri and Sugiyama assumed
in the applications and on an intuitive ground
The general exact solution for the many moments macroscopic approach to extended thermodynamics of polyatomic gases
A new model for Polyatomic and for Dense Gases has been proposed in literature in the last five years in
the framework of Extended Thermodynamics. The case with an arbitrary but fixed number of moments has been
recently studied, both with the kinetic approach than with the macroscopic approach; this last one is
more general and includes the results of the kinetic approach only as a particular case. \\
Scope of the "closure problem" is to find the expression of some arbitrary functions which appear in the
balance equations. Up to now only a recurrence procedure has been published which outlines how to find
the solution of this problem with the macroscopic approach; by using this procedure, a numberable set
of solutions has been found and written explicitly, while we find here the most general exact
solution. It is determined except for some arbirary terms and it is interesting that these terms appear
also in the 24 moments model; so we find here that they are transmitted from the model with 24 moments
to those with an arbitrary number of moments, without any further arbitrary term
Platinated Nucleotides are Substrates for the Human Mitochondrial Deoxynucleotide Carrier (DNC) and DNA Polymerase g: Relevance for the Development of New Platinum-Based Drugs.
cis-[PtCl2(NH3)2] (cisplatin) is among the highest effective antitumor drugs used for the chemotherapeutic treatment of a broad range of malignancies. Recently, alongside with the classical direct bond to DNA, an alternative mechanism of action mediated by N7 platinated nucleotides has been suggested for cisplatin. Considering that mitochondria play an important role in cell death activation and in a significant portion of the clinical activity and pharmacological properties associated with cisplatin,
aim of this research was to evaluate the possibility that platinated deoxynucleotides, as the model complex [Pt(dien)(N7-5’-dGTP)] (1), dien=diethylenetriamine, could be transported into mitochondria and then incorporated into mtDNA. The kinetic characterization has revealed that the mitochondrial deoxynucleotide carrier (DNC) transports complex 1 with high affinity. Finally, a highly efficient in organello DNA synthesis system, followed by ICP-AES, has demonstrated that [Pt(dien)(N7-5’-dGTP)] is incorporated in the mitochondrial DNA by DNA polymerase g. These results may have critical implications in the development of new generations of anticancer and/or antiviral nucleotide analogues with more specific cellular targets and fewer side effects
A Minimal Snap Extension to Improve the Treatment of Integer Data: A Constructionist Approach
Block based programming environments are a fundamental resource in introducing students to coding, an activity that has been proven to be useful in the development of competences laying in the field of mathematics. Unfortunately, it has been recently shown that Scratch, the most famous and diffused among those languages, presents an important lack in the treatment of Integer data: it does not provide easy and intuitive instruments to face problems dealing with the division with remainder. This conflicts with Scratch’s aim and could also bring students to create misconceptions about the division operation. For this reason, a minimal Snap extension will be here proposed, which overcomes this problem by creating a block environment more pertinent from a mathematical perspective
On the exact macroscopic approach to Extended Thermodynamics with 20 moments
Abstract: Extended Thermodynamics is the natural framework in which to study the physics of fluids, because it leads to symmetric hyperbolic systems of field laws, thus assuming important properties such as finite propagation speeds of shock waves and well posedness of the Cauchy problem. The closure of the system of balance equations is obtained by imposing the entropy principle and that of galilean relativity. If we take the components of the mean field as independent variables, these two principles are equivalent to some conditions on the entropy density and its flux. The method until now used to exploit these conditions, with the macroscopic approach, has not been used up to whatever order with respect to thermodynamical equilibrium. This is because it leads to several difficulties in calculations. Now these can be overcome by using a new method proposed recently by Pennisi and Ruggeri. Here we apply it to the 14 moments model. We will also show that the 13 moments case can be obtained from the present one by using the method of subsystems. AMS Subject Classification: 80A17, 74A20 Key Words: Extended Thermodynamics, entropy principle, hyperbolic systems
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