Search results for "FEL"

Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests

2021

Rock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-De…

Ernesta Felsberga Mākslas kabineta grāmatu kolekcija

2017

El reynante Belerophon hyspano, contra la enemiga chimera : respuesta de vn español professor de Minerva à monsieur Monsieur N. academico parisiense.

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Relacion diaria de todo lo sucedido en Madrid : desde el dia 20 de agosto, hasta el dia 3 de diziembre de este año de 1710, en que su Magestad entrò …

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Triunfos del Rey Nuestro Señor y obsequios de Valencia.

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Prenatally detected double trisomy: Klinefelter and Down syndrome

2006

Double trisomies are a rare occurrence. We report the first case of a Down and Klinefelter's syndrome (48,XXY,+21) in a fetus that was prenatally diagnosed during the 15th week of pregnancy. Even though the nasal bone was present, and the color-Doppler study of the ductus venosus and the nuchal thickness were normal, the maternal serum test results indicated an increased risk of Down syndrome and consequentially a genetic amniocentesis was performed. A 48,XXY,+21 karyotype was observed and the patient decided to terminate the pregnancy. In this case, we did not find the typical ultrasound (US) signs that would have led us to the chromosomopathy; furthermore, we emphasize the advantages of u…

A radiation condition for the 2-D Helmholtz equation in stratified media

2009

We study the 2-D Helmholtz equation in perturbed stratified media, allowing the existence of guided waves. Our assumptions on the perturbing and source terms are not too restrictive. We prove two results. Firstly, we introduce a Sommerfeld-Rellich radiation condition and prove the uniqueness of the solution for the studied equation. Then, by careful asymptotic estimates, we prove the existence of a bounded solution satisfying our radiation condition.

Effective interactions in Ricci-Based Gravity below the non-metricity scale

2020

We show how minimally-coupled matter fields of arbitrary spin, when coupled to Ricci-Based Gravity theories, develop non-trivial effective interactions that can be treated perturbatively only below a characteristic high-energy scale $\Lambda_Q$. Our results generalize to arbitrary matter fields those recently obtained for spin 1/2 fields in \cite{Latorre:2017uve}. We then use this interactions to set bounds on the high-energy scale $\Lambda_Q$ that controls departures of Ricci-Based Gravity theories from General Relativity. Particularly, for Eddington-inspired Born-Infeld gravity we obtain the strong bound $ |\kappa|<3.5 \times 10^{-14} \text{ m}^5 \text{kg}^{-1}\text{s}^{-2} $.

Born-Infeld f(R) gravity

2014

Motivated by the properties of matter quantum fields in curved space-times, we work out a gravity theory that combines the Born-Infeld gravity Lagrangian with an $f(R)$ piece. To avoid ghost-like instabilities, the theory is formulated within the Palatini approach. This construction provides more freedom to address a number of important questions such as the dynamics of the early universe and the cosmic accelerated expansion, among others. In particular, we consider the effect that adding an $f(R)=a R^2$ term has on the early-time cosmology. We find that bouncing solutions are robust against these modifications of the Lagrangian whereas the solutions with {\it loitering} behavior of the ori…

Wormholes and nonsingular spacetimes in Palatinif(R)gravity

2015

We reconsider the problem of $f(R)$ theories of gravity coupled to Born-Infeld theory of electrodynamics formulated in a Palatini approach, where metric and connection are independent fields. By studying electrovacuum configurations in a static and spherically symmetric space-time, we find solutions which reduce to their Reissner-Nordstr\"om counterparts at large distances but undergo important non-perturbative modifications close to the center. Our new analysis reveals that the point-like singularity is replaced by a finite-size wormhole structure, which provides a geodesically complete and thus nonsingular space-time, despite the existence of curvature divergences at the wormhole throat. …