Inflation targeting and economic performance: The case of Mexico

In the paper we analyze the impact of Inflation Targeting (IT) in Mexico. The objective is to evaluate the impact of the implementation of inflation targeting and full-fledged inflation targeting (FFIT) on the level and the variability of the inflation and the output in the Mexican economy. We conclude that inflation rates had been reduced in Mexico before the introduction of IT and FFIT. In our opinion, the structural reforms, including the Banxico reforms, are the main determinants of the decrease in inflation and its variability. The main impact of IT would have been the lock-in of inflation expectations around a low rate of inflation

Molecular simulation studies in periodic mesoporous silicas SBA-2 and STAC-1: model development and adsorption applications

Adsorption is a low-energy separation process especially advantageous when the components to be separated are similar in nature or have a low molar concentration. The choice of the adsorbent is the key factor for a successful separation, and among them periodic mesoporous silicas (PMS) are of importance because of their pore sizes, shapes and connectivity. Furthermore, they can be modified by post-synthesis functionalisation, which provides a tool for tailoring them to specific applications. SBA-2 and STAC-1 are two types of PMS characterised by a three-dimensional pore system of spherical cages interconnected by a network of channels whose formation process was until now obscure. In this work the kinetic Monte Carlo (kMC) technique has been extended to simulate the synthesis of these complex materials, presenting evidence that the interconnecting network originates from spherical micelles touching during their close-packing aggregation in the synthesis. Moreover, for the first time atomistic models for these materials were obtained with realistic pore-surface roughness and details of the possible location of its interaction sites. Grand Canonical Monte Carlo (GCMC) simulations of nitrogen, methane and ethane adsorption in the materials pore models show excellent agreement with experimental results. In addition, their potential as design tools is explored by introducing surface groups for enhancing CO2 capture; and finally, application examples are presented for carbon dioxide capture from flue gases and for natural gas purification, as well as in the separation of n-butane / iso-butane isomers

Computational study of uniaxial deformations in silica aerogel using a coarse-grained model

Simulations of a flexible coarse-grained model are used to study silica aerogels. This model, introduced in a previous study (J. Phys. Chem. C 2007, 111, 15792), consists of spherical particles which interact through weak nonbonded forces and strong interparticle bonds that may form and break during the simulations. Small-deformation simulations are used to determine the elastic moduli of a wide range of material models, and large-deformation simulations are used to probe structural evolution and plastic deformation. Uniaxial deformation at constant transverse pressure is simulated using two methods: a hybrid Monte Carlo approach combining molecular dynamics for the motion of individual particles and stochastic moves for transverse stress equilibration, and isothermal molecular dynamics simulations at fixed Poisson ratio. Reasonable agreement on elastic moduli is obtained except at very low densities. The model aerogels exhibit Poisson ratios between 0.17 and 0.24, with higher-density gels clustered around 0.20, and Young's moduli that vary with aerogel density according to a power-law dependence with an exponent near 3.0. These results are in agreement with reported experimental values. The models are shown to satisfy the expected homogeneous isotropic linear-elastic relationship between bulk and Young's moduli at higher densities, but there are systematic deviations at the lowest densities. Simulations of large compressive and tensile strains indicate that these materials display a ductile-to-brittle transition as the density is increased, and that the tensile strength varies with density according to a power law, with an exponent in reasonable agreement with experiment. Auxetic behavior is observed at large tensile strains in some models. Finally, at maximum tensile stress very few broken bonds are found in the materials, in accord with the theory that only a small fraction of the material structure is actually load-bearing

Molecular dynamics investigation of giant clustering in small-molecule solutions: the case of aqueous PEHA

[Image: see text] The importance of the formation of giant clusters in solution, in nature and industry, is increasingly recognized. However, relatively little attention has been paid to the formation of giant clusters in solutions of small, relatively soluble but nonamphiphilic molecules. In this work, we present a general methodology based on molecular dynamics that can be used to investigate such systems. As a case study, we focus on the formation of apparently stable clusters of pentaethylenehexamine (PEHA) in water. These clusters have been used as templates for the construction of bioinspired silica nanoparticles. To better understand clustering in this system, we study the effect of PEHA protonation state (neutral, +1, and +2) and counterion type (chloride or acetate) on PEHA clustering in dilute aqueous solutions (200 and 400 mM) using large-scale classical molecular dynamics. We find that large stable clusters are formed by singly charged PEHA with chloride or acetate as the counterion, although it is not clear for the case with acetate whether bulk phase separation, that might lead to precipitation, would eventually occur. Large clusters also appear to be stable for doubly charged PEHA with acetate, the less soluble counterion. We attribute this behavior to a form of complex coacervation, observed here for relatively small and highly soluble molecules (PEHA + counterion) rather than the large polyions usually found to form such coacervates. We discuss whether this behavior might also be described by an effective SALR (short-range attraction, long-range repulsion) interaction. This work might help future studies of additives for the design of novel bioinspired templated nanomaterials and of giant clustering in small-molecule solutions more generally

Two-dimensional sediment transport models in shallow water equations. A second order finite volume approach on unstructured meshes

In this paper, we study the numerical approximation of bedload sediment transport due to shallow layer flows. The hydrodynamical component is modeled by a 2D shallow water system and the morphodynamical component by a solid transport discharge formula that depends on the hydrodynamical variables. The coupled system can be written as a nonconservative hyperbolic system. To discretize it, first we consider a Roe-type first order scheme as well as a variant based on the use of flux limiters. These first order schemes are then extended to second order accuracy by means of a new MUSCL-type reconstruction operator on unstructured meshes. Finally, some numerical tests are presented

La Prosa narrativa de vanguardia en Chile

[Resumen] La tesis delimita los rasgos determinantes de la prosa narrativa en Chile como vriante subgenérica a partir del análisis de un conjunto representativo de obras similares en aspectos estructurales y constructivos, tratando de estudiar a los autores principales de la etapa

A conclusão do ensino secundário e a valorização académica dos militares

Este trabalho de investigação, subordinado ao tema “A Conclusão do Ensino Secundário e a Valorização Académica dos Militares” analisou o problema dos Praças da Marinha em Regime de Contrato (RC), comparativamente com os outros Ramos. A análise do problema foi efetuada com recurso às modalidades do Ensino à Distância (EAD) praticadas durante os últimos cinco anos. Uma das “grandes” modalidades, foi no passado, a criação de um Centro de Novas Oportunidades (CNO) coadunado ao Centro Naval de Ensino à Distância (CNED), para elevar os níveis académicos em Portugal até à escolaridade obrigatória, designada pela conclusão do 12º ano. A evolução nesta área tem sido uma constante. Com a Diretiva Sectorial dos Recursos Humanos de 2017, os cursos de formação de Praças viriam a sofrer alterações, ou seja, o reconhecimento dos seus estudos viria a ser obtido a nível externo, através da certificação por Unidades de Formação de Curta Duração (UFCD). Atualmente, os Centros Qualifica (CQ), são responsáveis pela modalidade da formação de Reconhecimento, Validação e Certificação de Competências (RVCC), modalidade á qual a Marinha Portuguesa (MP) passou a recorrer a partir de 2019, entre outras modalidades que tem o ensino à distância para conclusão do ensino secundário. Abstract: This research work, under the theme "The Completion of High School and the Academic Valorization of the Military" analyzed the problem of the enlisted personnelunder contract, compared to the other branches. One of the "big" modalities, was in the past, the creation of the Center of New Opportunities (CNO) linked to the Naval Center for Distance Education (CNED), as to the objective to raise the academic levels in Portugal up to the Compulsory Schooling designated by the conclusion of the 12th year. The evolution in this area has been a constant, that with the Human Resources Sector Directive of 2017, the formation courses for enlisted personnelwould suffer changes, meaning that the recognition of their studies would be obtained externally throw the certification of Short Term Formation Units (UFCD). Currently, the Qualify Centers (QC) are responsible for the modality that creates Recognition, Validation and Certification of Competencies (RVCC), modality in which the Portuguese Navy (MP) started to appeal at 2019, between other modalities that have distance learning to conclusion of high school.N/

Guidelines for the edition of medieval Galician-Portuguese troubadour poetry

[Resumo]Exposición pormenorizada das Normas de Edición para a poesía trobadoresca galego-portuguesa, a partir dos debates e decisións acordadas no Coloquio da Illa de San Simón (2006) polos máis importantes especialistas galegos neste ámbito. O texto das Normas aparece en diversas linguas: galego, portugués, italiano, español, francés, inglés.Ministerio de Ciencia y Tecnología; HUM2004-0430