Squark-mediated Higgs+jets production at the LHC

We investigate possible scenarios of light-squark production at the LHC as a new mechanism to produce Higgs bosons in association with jets. The study is motivated by the SUSY search for H+jets events, performed by the CMS collaboration on 8 and 13 TeV data using the razor variables. Two simplified models are proposed to interpret the observations in this search. The constraint from Run I and the implications for Run II and beyond are discussed

The unphysical character of dark energy fluids

It is well known that, in the context of general relativity, an unknown kind of matter that must violate the strong energy condition is required to explain the current accelerated phase of expansion of the Universe. This unknown component is called dark energy and is characterized by an equation of state parameter $w=p/\rho<-1/3$. Thermodynamic stability requires that $3w-d\ln |w|/d\ln a\ge0$ and positiveness of entropy that $w\ge-1$. In this paper we proof that we cannot obtain a differentiable function $w(a)$ to represent the dark energy that satisfies these conditions trough the entire history of the Universe.Comment: 8 pages, 1 figur

Investigação em ensino das ciências : influências ao nível dos manuais escolares

Uma das áreas mais determinantes da investigação em educação em ciências reporta-se à identificação das concepções alternativas dos alunos e à proposta/implementação de modelos de ensino que visem a mudança conceptual. Constituindo o manual escolar um dos materiais de apoio mais utilizados pelos professores, determinando frequentemente a natureza da actividade científica desenvolvida na sala de aula, parece revestir-se de importância o estudo da influência da investigação em ciências, especificamente na problemática anteriormente explicitada, ao nível dos manuais escolares. Este artigo tem, assim, como objectivos: 1. Analisar, brevemente, o desenvolvimento da investigação que tem vindo a ser feita no domínio da problemática das concepções alternativas e da mudança conceptual; 2. Apresentar os principais resultados de investigações onde se procurou avaliar a influência do manual escolar na prática dos professores de ciências e na aprendizagem dos alunos; 3. Apresentar uma análise de manuais escolares de Ciências da Natureza.One of the most determinant areas of research on science education is the identification of the students' alternative conceptions and the proposal/implementation of teaching models aimed at conceptual change. School textbooks are widely used by teachers as a support material and often determine the nature of the scientific activity carried out in the classroom. Therefore, it seems important to investigate the impact of science research upon school textbooks, especially on the area referred to above. The purpose of this paper is: 1. To analyse briefly the developments of research on the area of alternative conceptions and conceptual change; 2. To present the main results of research studies where the role of textbooks in science teaching and learning was analysed; 3. To present a study where science textbooks are analysed.L'un des domaines des plus déterminants de la recherche en éducation des sciences est celui de l'identification des conceptions alternatives des élèves et de la proposition/implantation de modèles d'enseigne-ment qui visent le changement conceptuel. Le manuel scolaire, constituant l'un des appuis les plus utilisés par les professeurs et déterminant fréquemment la nature de l'activité scientifique développée en classe, il semble important de rechercher quelle est l'influence de l'investigation en sciences, en ce qui concerne cette problématique, au niveau des manuels scolaires. Ainsi, cet article a pour objectifs: 1. Analyser, brièvement, le développement de la recherche qui se réalise sur la problématique des conceptions alternatives et du changement conceptuel; 2. Présenter les principaux résultats d'investigations dans lesquelles on a recherché à évaluer l'influence du manuel scolaire dans la pratique des professeurs de sciences et dans l'apprentissage des élèves; 3. Présenter une étude d'analyse de manuels scolaires de Sciences Naturelles

Supercritical antisolvent precipitation of PHBV microparticles

The micronization of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from organic solutions using supercritical antisolvent (SAS) technique has been successfully achieved. SASexperiments were carried out at different operational conditions and microspheres with mean diameters ranging from 3 to 9 mwere obtained. The effect of CO2 and liquid flow, temperature and pressure on particle size and particle size distribution was evaluated. The microspheres were precipitated from a dichloromethane (DCM) solution. The best process conditions for this mixture were, according to our study, 40 ◦C, 100 bar, 1mLmin−1 liquid flow and 10 L min−1 carbon dioxide flow. Experiments with polymers containing different HV percentages were carried out. The powders obtained became more spherical as the HV content decreased

Solving 1ODEs with functions

Here we present a new approach to deal with first order ordinary differential equations (1ODEs), presenting functions. This method is an alternative to the one we have presented in [1]. In [2], we have establish the theoretical background to deal, in the extended Prelle-Singer approach context, with systems of 1ODEs. In this present paper, we will apply these results in order to produce a method that is more efficient in a great number of cases. Directly, the solving of 1ODEs is applicable to any problem presenting parameters to which the rate of change is related to the parameter itself. Apart from that, the solving of 1ODEs can be a part of larger mathematical processes vital to dealing with many problems.Comment: 31 page

Clone size distributions in networks of genetic similarity

We build networks of genetic similarity in which the nodes are organisms sampled from biological populations. The procedure is illustrated by constructing networks from genetic data of a marine clonal plant. An important feature in the networks is the presence of clone subgraphs, i.e. sets of organisms with identical genotype forming clones. As a first step to understand the dynamics that has shaped these networks, we point up a relationship between a particular degree distribution and the clone size distribution in the populations. We construct a dynamical model for the population dynamics, focussing on the dynamics of the clones, and solve it for the required distributions. Scale free and exponentially decaying forms are obtained depending on parameter values, the first type being obtained when clonal growth is the dominant process. Average distributions are dominated by the power law behavior presented by the fastest replicating populations.Comment: 17 pages, 4 figures. One figure improved and other minor changes. To appear in Physica

Non universality of entanglement convertibility

Recently, it has been suggested that operational properties connected to quantum computation can be alternative indicators of quantum phase transitions. In this work we systematically study these operational properties in 1D systems that present phase transitions of different orders. For this purpose, we evaluate the local convertibility between bipartite ground states. Our results suggest that the operational properties, related to non-analyticities of the entanglement spectrum, are good detectors of explicit symmetries of the model, but not necessarily of phase transitions. We also show that thermodynamically equivalent phases, such as Luttinger liquids, may display different convertibility properties depending on the underlying microscopic model.Comment: 5 pages + references, 4 figures - improved versio

The politicization of immigration in Portugal between 1995 and 2014: a European exception?

Immigration is envisaged as part of an ‘emergent cultural cleavage’ across Western Europe. Within this context, this article explores the politicization of immigration in Portugal between 1995 and 2014. Politicization is interpreted as being formed by two distinct dimensions: salience and polarization of the political claims found within news articles extracted from newspapers. Notwithstanding the doubling of the foreign population settled in the country in the early 2000s, the diminished salience and the absence of significant political conflict suggest that immigration failed to become politicized in Portugal. Drawing on a comparative analysis with seven other European states between 1995 and 2009, Portugal observed the lowest rate of politicization. Rather than being related with socio‐economic factors, the lack of politicization of immigration was associated with the strategies of the mainstream parties, which successfully prevented the emergence of this topic as a significant political cleavage.info:eu-repo/semantics/acceptedVersio

Preparation of controlled release microspheres using supercritical fluid technology for delivery of anti-inflammatory drugs

Ethylcellulose/methylcellulose blends were produced using different precipitation techniques and impregnated with naproxen, a non-steroidal anti-inflammatory drug (NSAID). Solvent-evaporation technique was used not only for the preparation of ethylcellulose/methylcellulose microspheres but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxen loaded microspheres. The microspheres, impregnated by the SCF technique, were prepared both by solvent-evaporation and by a supercritical antisolvent (SAS) process. In vitro release profiles at pH 7.4 and 1.2, of naproxen-loaded microspheres were evaluated and the results were modelled Fick’s law of diffusion and Power law. Miscrospheres prepared by supercritical antisolvent have a higher loading capacity and present a slower release profile. The systems studied present a release mechanism controlled by drug diffusion which complies Fick’s law of diffusion

A comparison between gravimetric and in-situ spectroscopic methods to measure the sorption of CO₂in a biocompatible polymer

In situ ATR-IR spectroscopy was used to simultaneously measure the sorption and swelling of carbon dioxide at high pressures in a biocompatible acrylate copolymer poly(methylmethacrylate-co-ethylhexylacrylate-co-ethyleneglycoldimethacrylate), P(MMA–EHA–EGDMA). The ν3 band of CO2 dissolved in the polymer (at 2335 cm−1) was used to calculate the sorption data and the polymer swelling was determined by analyzing the changes in the absorbance of the ν(C O) band (at 1730 cm−1) of the polymer. Transmission spectroscopy in the near-IR region was also used to study the sorption of CO2 in the polymer using combinational and overtone bands. The experiments were carried out in a pressure range of 2.0–12.0MPa and in a temperature range of 27–40 ◦C. The data for CO2 sorption in this polymer obtained by in situ spectroscopic methods have been compared to the data obtained by the gravimetric technique