22,332 research outputs found
Microwave-Assisted Extraction of Brewers' Spent Grain Arabinoxylans
Brewers´ spent grain (BSG) is a by-product from beer industry that can be exploited as a source of
arabinoxylo-oligosaccharides (AXOS) with prebiotic activity. In this study, microwave-assisted extractions were
performed during 2 min at 140-210°Cin order to evaluate the feasibility of this extraction technology for quantitative
extraction of the arabinoxylans (AX) or AXOS from BSG. The AX yield increasedwith the increase of the temperature
in the range used. The best condition of extraction of the AXwas 210 ºC during 2 min, allowing the extraction of 43%
of total AX. These AX showed structural variability which allow to define specific types of compounds for different
applications and uses depending on the extraction conditions used
The extended minimal geometric deformation of SU() dark glueball condensates
The extended minimal geometric deformation (EMGD) procedure, in the
holographic membrane paradigm, is employed to model stellar distributions that
arise upon self-interacting scalar glueball dark matter condensation. Such
scalar glueballs are SU() Yang-Mills hidden sectors beyond the Standard
Model. Then, corrections to the gravitational wave radiation, emitted by
SU() EMGD dark glueball stars mergers, are derived, and their respective
spectra are studied in the EMGD framework, due to a phenomenological brane
tension with finite value. The bulk Weyl fluid that drives the EMGD is then
proposed to be experimentally detected by enhanced windows at the eLISA and
LIGO.Comment: 9 pages, 7 figure
Extended quantum portrait of MGD black holes and information entropy
The extended minimal geometric deformation (EMGD) is employed on the fluid
membrane paradigm, to describe compact stellar objects as Bose--Einstein
condensates (BEC) consisting of gravitons. The black hole quantum portrait,
besides deriving a preciser phenomenological bound for the fluid brane tension,
is then scrutinized from the point of view of the configurational entropy. It
yields a range for the critical density of the EMGD BEC, whose configurational
entropy has global minima suggesting the configurational stability of the EMGD
BEC.Comment: 9 pages, 7 figures, matches the published versio
Non-Associativity in the Clifford Bundle on the Parallelizable Torsion 7-Sphere
In this paper we discuss generalized properties of non-associativity in
Clifford bundles on the 7-sphere S7. Novel and prominent properties inherited
from the non-associative structure of the Clifford bundle on S7 are
demonstrated. They naturally lead to general transformations of the spinor
fields on S7 and have dramatic consequences for the associated Kac-Moody
current algebras. All additional properties concerning the non-associative
structure in the Clifford bundle on S7 are considered. We further discuss and
explore their applications.Comment: 16 page
Angular Momentum of the BTZ Black Hole in the Teleparallel Geometry
We carry out the Hamiltonian formulation of the three- dimensional
gravitational teleparallelism without imposing the time gauge condition, by
rigorously performing the Legendre transform. Definition of the gravitational
angular momentum arises by suitably interpreting the integral form of the
constraint equation Gama^ik=0 as an angular momentum equation. The
gravitational angular momentum is evaluated for the gravitational field of a
rotating BTZ black hole.Comment: 17 pages, no figures, v2: some misprints corrected, Ref.s added, Eq.s
revised, submitted to General Relativity and Gravitatio
Anisotropic solutions by gravitational decoupling
We investigate the extension of isotropic interior solutions for static
self-gravitating systems to include the effects of anisotropic spherically
symmetric gravitational sources by means of the gravitational decoupling
realised via the minimal geometric deformation approach. In particular, the
matching conditions at the star surface with the outer Schwarzschild space-time
are studied in great details, and we describe how to generate, from a single
physically acceptable isotropic solution, new families of anisotropic solutions
whose physical acceptability is also inherited from their isotropic parent.Comment: 20 pages, 4 figures; references and typos corrected; final version to
match the EPJC versio
Eisenstein Series and String Thresholds
We investigate the relevance of Eisenstein series for representing certain
-invariant string theory amplitudes which receive corrections from BPS
states only. may stand for any of the mapping class, T-duality and
U-duality groups , or respectively.
Using -invariant mass formulae, we construct invariant modular functions
on the symmetric space of non-compact type, with the
maximal compact subgroup of , that generalize the standard
non-holomorphic Eisenstein series arising in harmonic analysis on the
fundamental domain of the Poincar\'e upper half-plane. Comparing the
asymptotics and eigenvalues of the Eisenstein series under second order
differential operators with quantities arising in one- and -loop string
amplitudes, we obtain a manifestly T-duality invariant representation of the
latter, conjecture their non-perturbative U-duality invariant extension, and
analyze the resulting non-perturbative effects. This includes the and
couplings in toroidal compactifications of M-theory to any
dimension and respectively.Comment: Latex2e, 60 pages; v2: Appendix A.4 extended, 2 refs added, thms
renumbered, plus minor corrections; v3: relation (1.7) to math Eis series
clarified, eq (3.3) and minor typos corrected, final version to appear in
Comm. Math. Phys; v4: misprints and Eq C.13,C.24 corrected, see note adde
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