2,162 research outputs found
Weyl geometry approach to describe planetary systems
In the present work we show that planetary mean distances can be calculated
through considering the Weyl geometry. We interpret the Weyl gauge field as a
vector field associated with the hypercharge of the particles and apply the
gauge concept of the Weyl geometry. The results obtained are shown to agree
with the observed orbits of all the planets and of the asteroid belt in the
solar system, with some empty states.Comment: 7 pages, no figure
Geometrical features of (4+d) gravity
We obtain the vacuum spherical symmetric solutions for the gravitational
sector of a (4+d)-dimensional Kaluza-Klein theory. In the various regions of
parameter space, the solutions can describe either naked singularities or
black-holes or wormholes. We also derive, by performing a conformal rescaling,
the corresponding picture in the four-dimensional space-time.Comment: 10 pages, LateX2e, to appear in Phys.Rev.
Possible Wormhole Solutions in (4+1) Gravity
We extend previous analyses of soliton solutions in (4+1) gravity to new
ranges of their defining parameters. The geometry, as studied using invariants,
has the topology of wormholes found in (3+1) gravity. In the induced-matter
picture, the fluid does not satisfy the strong energy conditions, but its
gravitational mass is positive. We infer the possible existance of (4+1)
wormholes which, compared to their (3+1) counterparts, are less exotic.Comment: 3 pages, latex, 1 figure
To comply or not to comply? How a UEFA wage-to-revenue requirement might affect the sport and managerial performance of soccer clubs
This paper evaluates the soccer clubs' compliance with a potential wage-to-revenue requirement by the Union of European Football Associations (UEFA) and studies the effect on sport achievements resulting from sports and managerial skills. The empirical analysis uses data on first division teams of the Premier League, La Liga, Serie A, and Ligue 1, from seasons 2009/2010 to 2018/2019. We measure the teams' quality through the annual wages and use the wage-to-revenue ratio as a proxy measure for financial responsibility. Our results reveal that a more prudent financial performance, which is generally linked to good management practices, implies better sport performance and higher chances of qualifying for UEFA competitions
Adsorption of phenol/tyrosol from aqueous solutions on macro-reticular aromatic and macro-porous polystyrene cross-linked with divinylbenzene polymeric resins
The current work aims at separating by adsorption of low-molecular-weight organic compounds in a
nanofiltration concentrate of the olive mill wastewaters. The experimental investigations on adsorption of
phenol/tyrosol in single and binary systems were conducted in batch mode by using the commercially
available macroporous resins FPX66 and MN202. The structures of such resins were examined by FTIR
before and after adsorption. The operating parameters affecting the adsorption process such as resin dosage,
contact time, pH, and initial concentration of phenol/tyrosol were investigated. Fast phenol and tyrosol uptakes
were observed for both resins. It can be attributed to their physical properties, for instance high specific area
and microporous area. The adsorption selectivity of phenol is larger than tyrosol when using FPX66 resin, but
smaller if MN202 resin is used. Acidic pH appeared to be always favourable for the adsorption. A synergetic
effect between solutes was observed since adsorption of phenol and tyrosol in the binary systems was faster
than the individual sorption of each solute. Five isotherms namely Langmuir, Freundlich, DubininRadushkevich,
Temkin and Redlich-Peterson were selected to fit the obtained equilibrium experimental data.
Finally, desorption of the examined compounds with ethanol (EtOH) allowed a maximum around 85 % of
phenol, and equal to 94 % of tyrosol on FPX66 and MN202 resins
Adsorption of phenol/tyrosol from aqueous solutions on macro-reticular aromatic and macro-porous polystyrene cross-linked with divinylbenzene polymeric resins
The current work aims at separating by adsorption of low-molecular-weight organic compounds in a
nanofiltration concentrate of the olive mill wastewaters. The experimental investigations on adsorption of
phenol/tyrosol in single and binary systems were conducted in batch mode by using the commercially
available macroporous resins FPX66 and MN202. The structures of such resins were examined by FTIR
before and after adsorption. The operating parameters affecting the adsorption process such as resin dosage,
contact time, pH, and initial concentration of phenol/tyrosol were investigated. Fast phenol and tyrosol uptakes
were observed for both resins. It can be attributed to their physical properties, for instance high specific area
and microporous area. The adsorption selectivity of phenol is larger than tyrosol when using FPX66 resin, but
smaller if MN202 resin is used. Acidic pH appeared to be always favourable for the adsorption. A synergetic
effect between solutes was observed since adsorption of phenol and tyrosol in the binary systems was faster
than the individual sorption of each solute. Five isotherms namely Langmuir, Freundlich, DubininRadushkevich,
Temkin and Redlich-Peterson were selected to fit the obtained equilibrium experimental data.
Finally, desorption of the examined compounds with ethanol (EtOH) allowed a maximum around 85 % of
phenol, and equal to 94 % of tyrosol on FPX66 and MN202 resins
"Spin-Disentangled" Exact Diagonalization of Repulsive Hubbard Systems: Superconducting Pair Propagation
By a novel exact diagonalization technique we show that bound pairs propagate
between repulsive Hubbard clusters in a superconducting fashion. The size of
the matrices that must be handled depends on the number of fermion
configurations {\em per spin}, which is of the order of the square root of the
overall size of the Hilbert space. We use CuO units connected by weak O-O
links to model interplanar coupling and c-axis superconductivity in Cuprates.
The numerical evidence on CuO and CuO prompts a new
analytic scheme describing the propagation of bound pairs and also the
superconducting flux quantization in a 3-d geometry.Comment: 5 pages, 3 figure
A novel mutation in SACS gene in a family from southern Italy
A form of autosomal recessive spastic ataxia (ARSACS) has been described in the
Charlevoix and Saguenay regions of Quebec. So far a frameshift and a nonsense
mutation have been identified in the SACS gene. The authors report a new mutation
(1859insC), leading to a frameshift with a premature termination of the gene
product sacsin, in two sisters from consanguineous parents. The phenotype is
similar to previously described patients with ARSACS
The Age-Redshift Relation for Standard Cosmology
We present compact, analytic expressions for the age-redshift relation
for standard Friedmann-Lema\^ \itre-Robertson-Walker (FLRW)
cosmology. The new expressions are given in terms of incomplete Legendre
elliptic integrals and evaluate much faster than by direct numerical
integration.Comment: 13 pages, 3 figure
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