Search results for "Reno"
showing 10 items of 1031 documents
Brewer's spent grains as biofuels in combustion-based energy recovery processes: Evaluation of thermo-oxidative decomposition
2022
[EN] The high global generation of wastes and side streams from agri-food production has led to environmental impact and causes nature degradation due to their uncontrolled management. These wastes are profitable materials with significant economic value that could otherwise be exploited as new sources in the feed industry or the production of bioenergy. Among them, brewer¿s spent grain (BSG) is a solid by-product generated in the beerbrewing process that consists of the barley grain husks together with parts of the pericarp and seed coat layer. Although it is rich in fibres and proteins, its main use is currently limited to animal feed or simply deposition to landfills. This study pursues …
Study of economic availability related to rare metals in the context of the energy transition
2014
A growing number of academic studies and international organizations reports have noticed an increasing dependency of new energy technologies on a specific class of natural resources often called minor metals. For several years, worries about economic availability of these metals in order to realize the energy transition have appeared. This thesis aims at underline the broader risks and constraints involved by general use of these metals in new energy technologies. A first part of this thesis is devoted to theories and indicators related to the depletion of non renewable resources. This part also shows that minor metals share many characteristics and that they can form a group of metal cons…
A New Analysis of the Three-Body Problem
2022
In the recent papers [5, 18], respectively, the existence of motions where the perihelions afford periodic oscillations about certain equilibria and the onset of a topological horseshoe have been proved. Such results have been obtained using, as neighbouring integrable system, the so-called two-centre (or Euler) problem and a suitable canonical setting proposed in [16, 17]. Here we review such results.
Chen’s iterated integral represents the operator product expansion
1999
The recently discovered formalism underlying renormalization theory, the Hopf algebra of rooted trees, allows to generalize Chen’s lemma. In its generalized form it describes the change of a scale in Green functions, and hence relates to the operator product expansion. Hand in hand with this generalization goes the generalization of the ordinary factorial n! to the tree factorial t. Various identities on tree-factorials are derived which clarify the relation between Connes-Moscovici weights and Quantum Field Theory.
A Positive Definite Advection Scheme Obtained by Nonlinear Renormalization of the Advective Fluxes
1989
Abstract A new method is developed to obtain a conservative and positive definite advection scheme that produces only small numerical diffusion. Advective fluxes are computed utilizing the integrated flux form of Tremback et al. These fluxes are normalized and then limited by upper and lower values. The resulting advection equation is numerically solved by means of the usual upstream procedure. The proposed treatment is not restricted to the integrated flux form but may also be applied to other known advection algorithms which are formulated in terms of advective fluxes. Different numerical tests are presented illustrating that the proposed scheme strongly reduces numerical and diffusion an…
NNLO QED contribution to the µe → µe elastic scattering
2020
We present the current status of the Next-to-Next-to-Leading Order QED contribution to theµescattering. Particular focus is given to the techniques involved to tackle the virtual amplitude and their automatic implementation. Renormalization of the amplitude will be also discuss in details.
Two-loop electroweak corrections to the ρ parameter beyond the leading approximation
1996
We show that in the framework of the pinch technique the universal part of the $\rho$ parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies the crucial requirements of gauge-independence, finiteness, and process-independence, even when subleading contributions of the top quark are included. The mechanism which enforces the aforementioned properties is explained in detail, and several subtle field theoretical issues are discussed. Explicit calculations of the sub-leading two-loop corrections of order $O(G_{\mu}^{2}m^{2}_{t}M_{Z}^{2})$ are carried out in the context of an $SU(2)$ model, with $M_{W}=M_{Z}$, and various intermediate and final results a…
Inflation, quantum fields, and CMB anisotropies
2009
Revert field Inflationary cosmology has proved to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly influences the generation of primordial perturbations and hence the expected measurable imprint of cosmological inflation on the CMB. However, the new predictions remain in agreement with observation, and in fact favor the simplest forms of inflation. In the near future, observations of the influence of gravitational waves from the early universe on the CMB will test our new predictions.
Anharmonicity-induced polaron relaxation in GaAs/InAs quantum dots
2002
The anharmonicity-induced relaxation of a polaron in a quantum dot is analyzed using the Davydov diagonalization method, including the coherent renormalization of the relevant third-order phonon interaction. The resulting relaxation time for a small GaAs/InAs self-assembled quantum dot turns out to be a few times longer than that found previously by a perturbative method.
HIERARCHICAL MELTING OF ONE-DIMENSIONAL INCOMMENSURATE STRUCTURES
2016
We study the low—temperature properties of quasi one—dimensional, incommensurate structures which are described by a Frenkel—Kontorova—like model. A new type of renormalization method will be presented, which is determined by the continued fraction expansion of the incommensurability ratio ζ. (This method yields a hierarchy of renormalized Hamiltonians ϰ(n,p) describing the thermal behavior for temperatures T = O(T(n,p)), where T(n,p) follows from the continued fraction expansion of ζ. By means of this method the low—temperature specific heat c(T) and the static structure factor S(q) are calculated for fixed ζ. c(T) possesses a hierarchy of Schottky anomalies related to the rational approxi…