Predicting with confidence the efficiency of new dyes in dye sensitized solar cells

We ask whether it is possible to predict the efficiency of a new dye in dye sensitized solar cells (DSSCs) on the basis of the known performance of existing dyes in the same type of device. We evaluate a number of computable predictors of the efficiency for a large set of dyes whose experimental efficiency is known. We have then used statistical regression methods to establish the relation between the predictors and the efficiency. Our predictions are associated with a rigorously determined confidence level. For a new dye of the same family we are able to predict the probability that its efficiency in a DSSC is larger than a certain threshold. This method is useful for accelerating the discovery of new dyes and establishing more rigorously the existence of specific correlations between structure and properties. Within the properties considered we find that the dye efficiency correlates more strongly with its oxidation potential and reorganization energy

P-RANSAC: An Integrity Monitoring Approach for GNSS Signal Degraded Scenario

Satellite navigation is critical in signal-degraded environments where signals are corrupted and GNSS systems do not guarantee an accurate and continuous positioning. In particular measurements in urban scenario are strongly affected by gross errors, degrading navigation solution; hence a quality check on the measurements, defined as RAIM, is important. Classical RAIM techniques work properly in case of single outlier but have to be modified to take into account the simultaneous presence of multiple outliers. This work is focused on the implementation of random sample consensus (RANSAC) algorithm, developed for computer vision tasks, in the GNSS context. This method is capable of detecting multiple satellite failures; it calculates position solutions based on subsets of four satellites and compares them with the pseudoranges of all the satellites not contributing to the solution. In this work, a modification to the original RANSAC method is proposed and an analysis of its performance is conducted, processing data collected in a static test

Elliptic equations with discontinuous coefficients in unbounded domains of R^2

In this paper we are concerned with second order elliptic equations in unbounded domains Ω of R^2 . We establish existence and uniqueness theorems under the assumptions that the leading coefficients are bounded and measurable in Ω and satisfy a suitable condition at infinity

Elliptic equations with discontinuous coefficients in unbounded domains of R^2

In this paper we are concerned with second order elliptic equations in unbounded domains Ω of R^2 . We establish existence and uniqueness theorems under the assumptions that the leading coefficients are bounded and measurable in Ω and satisfy a suitable condition at infinity

Axion field influence on Josephson junction quasipotential

The direct effect of an axion field on Josephson junctions is analyzed through the consequences on the effective potential barrier that prevents the junction from switching from the superconducting to the finite-voltage state. We describe a method to reliably compute the quasipotential with stochastic simulations, which allows to span the coupling parameter from weakly interacting axion to tight interactions. As a result, we obtain that the axion field induces a change in the potential barrier, therefore determining a significant detectable effect for such a kind of elusive particle.Comment: 12 pages, 3 figure

As repúblicas chegam ao mundo luso: Brasil e Portugal, 1889-1930

Este capítulo pretende entender o declínio da monarquia no Brasil e em Portugal e de maneira comparada e integrada, concentrando-se nos aspectos particulares e, ao mesmo tempo, comuns de cada processo. O objetivo desse esforço é compreender as motivações que levaram ambos os países ao republicanismo, lançando luz sobre o que representou esse processo para as classes subalternas. Desse modo, nossa proposta é guiar-nos por uma história social, ou uma história vista de baixo, que se atente aos efeitos sentidos pelas camadas desfavorecidas com essa transição política. No entanto, recorreremos à história política para uma breve contextualização das transformações ocorridas no âmbito das elites e dos governos depostos e recém-instaurados. Além disso, tentaremos entender de que forma os dois movimentos se conectam, tentando encontrar possíveis impactos da transição brasileira em Portugal. É importante ressaltar que as histórias do Brasil e de Portugal tiveram um tronco comum até 1822, quando o primeiro país se tornou independente do segundo. Após a separação, e até meados do século 20, os dois estados experimentaram sucessivamente as mesmas fases de transformação política: monarquia constitucional, república e Estado Novo. Apesar dessas semelhanças, houve poucas tentativas de comparar suas histórias modernas. Este capítulo é uma tentativa de fazê-lo, enfocando as menos frequentadas dessas comparações, as das primeiras repúblicas brasileira e portuguesa. Procuraremos encontrar pontos comuns e diferentes entre uma república brasileira que chegou tarde em um contexto sul-americano que já se voltou em massa para esta opção, e uma república portuguesa que chegou cedo demais a um continente ainda em grande parte monárquico. Por fim, exploraremos os respectivos fracassos de ambos os regimes que abririam as portas a soluções autoritárias dos dois lados do Atlântico português.Facultad de Humanidades y Ciencias de la Educació

A Glycerol-Based Deep Eutectic Solvent as Natural Medium and Organic Reductant for Homocoupling of (Hetero)Aryl Chlorides: a Green Route to 2,2’-Bipyridine and Biaryl Scaffolds

A glycerol-based Deep Eutectic Solvent (DES) enables the Pd-catalyzed activation of (hetero)arylchlorides and promotes the formation of 2,2’-bipiyridines and biaryls through an Ullmann-type homocoupling in smooth experimental conditions (80 °C) with Ca(OH)2 as a green base and Pd/C as heterogeneous catalyst. Noteworthy, the coupling does not need the addition of external reducing agents, like metals, since the glycerol present in the DES acts as a safe and green organic reductant. The heterogeneous catalytic system (DES-Pd/C) showed to be easily recyclable and has been applied to the sustainable synthesis of the Abametapir drug