CuxS thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu2S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1-0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of CuxS films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 degrees C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show CuxS films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the CuxS films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of CuxS surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of CuxS films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the CuxS material. (c) 2013 Elsevier B.V. All rights reserved.

Phosphorus-doped amorphous silicon thin films, deposited at low temperatures by Plasma Enhanced Chemical Vapour Deposition were used as a dopant source on p-type c-Si substrates. A careful step of dehydrogenation was done in order to maintain the a-Si thin-film integrity. Subsequently, a fine-controlled drive-in of dopant, from the amorphous layer to the crystalline wafer was done, to form the p/n junction, using different time periods and temperatures. Dopant profiling in c-Si wafers as well as dopant concentration in a-Si: H films prior to diffusion, both measured by Secondary Ion Mass Spectrometry, are presented. Junction depths obtained are in the range of 98 nm to 2.4 mu m and surface concentrations are in the range of 1.1 x 10(21) to 4.3 x 10(20) at/cm(3). A dual diffusion mechanism explains the ``kink-and-tail{''} shape found for dopant profile. (C) 2013 Elsevier B.V. All rights reserved.

Phosphorus-doped amorphous silicon thin films, deposited at low temperatures by Plasma Enhanced Chemical Vapour Deposition were used as a dopant source on p-type c-Si substrates. A careful step of dehydrogenation was done in order to maintain the a-Si thin-film integrity. Subsequently, a fine-controlled drive-in of dopant, from the amorphous layer to the crystalline wafer was done, to form the p/n junction, using different time periods and temperatures. Dopant profiling in c-Si wafers as well as dopant concentration in a-Si: H films prior to diffusion, both measured by Secondary Ion Mass Spectrometry, are presented. Junction depths obtained are in the range of 98 nm to 2.4 mu m and surface concentrations are in the range of 1.1 x 10(21) to 4.3 x 10(20) at/cm(3). A dual diffusion mechanism explains the ``kink-and-tail{''} shape found for dopant profile. (C) 2013 Elsevier B.V. All rights reserved.

A programação concorrente obriga o programador a sincronizar os acessos concorrentes a regiões de memória partilhada, contudo esta abordagem não é suficiente para evitar todas as anomalias que podem ocorrer num cenário concorrente. Executar uma sequência de operações atómicas pode causar violações de atomicidade se existir uma correlação entre essas operações, devendo o programador garantir que toda a sequência de operações é executada atomicamente. Este problema é especialmente comum quando se usam operações de pacotes ou módulos de terceiros, pois o programador pode identificar incorretamente o âmbito das regiões de código que precisam de ser atómicas para garantir o correto comportamento do programa. Para evitar este problema o programador do módulo pode criar um contrato que especifica quais as sequências de operações do módulo que devem ser sempre executadas de forma atómica. Este trabalho apresenta uma análise estática para verificação destes contratos.

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The effect of post-deposition annealing temperature on the pH sensitivity of room temperature RF sputtered Ta₂O₅ was investigated. Structural and morphological features of these films were analyzed before and after annealing at various temperatures. The deposited films are amorphous up to 600 °C and crystallize at 700 °C in an orthorhombic phase. Electrolyte-insulator-semiconductor (EIS) field effect based sensors with an amorphous Ta2O5 sensing layer showed pH sensitivity above 50 mV/pH. For sensors annealed above 200 °C pH sensitivity decreased with increasing temperature. Stabilized sensor response and maximum pH sensitivity was achieved after low temperature annealing at 200 °C, which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors.

This research has been motivated by a real-life problem of a waste cooking oil collection system characterized by the existence of multiple depots with an outsourced vehicle fleet, where the collection routes have to be plan. The routing problem addressed allows open routes between depots, i.e., all routes start at one depot but can end at the same or at a different one, depending on what minimizes the objective function considered. Such problem is referred as a Multi-Depot Vehicle Routing Problem with Mixed Closed and Open Inter-Depot Routes and is, in this paper, modeled through a Mixed Integer Linear Programming (MILP) formulation where capacity and duration constraints are taken into account. The model developed is applied to the real case study providing, as final results, the vehicle routes planning where a decrease of 13% on mileage and 11% on fleet hiring cost are achieved, when comparing with the current company solution.

The preferential binding of anions and cations in aqueous solutions of the ionic liquids (ILs) 1-butyl- 3-methylimidazolium ([C₄mim]⁺) and 1-ethyl-3-methylimidazolium ([C₂mim]⁺) chloride and dicyanamide (dca^-) with the small alpha-helical protein Im7 was investigated using a combination of differential scanning calorimetry, NMR spectroscopy and molecular dynamics (MD) simulations. Our results show that direct ion interactions are crucial to understand the effects of ILs on the stability of proteins and that an anion effect is dominant. We show that the binding of weakly hydrated anions to positively charged or polar residues leads to the partial dehydration of the backbone groups, and is critical to control stability, explaining why dca^- is more denaturing than Cl^-. Direct cation–protein interactions also mediate stability; cation size and hydrophobicity are relevant to account for destabilisation as shown by the effect of [C₄mim]⁺ compared to [C₂mim]⁺. The specificity in the interaction of IL ions with protein residues established by weak favourable interactions is confirmed by NMR chemical shift perturbation, amide hydrogen exchange data and MD simulations. Differences in specificity are due to the balance of interaction established between ion pairs and ion-solvent that determine the type of residues affected. When the interaction of both cation and anion with the protein is strong the net result is similar to a non-specific interaction, leading ultimately to unfolding. Since the nature of the ions is a determinant of the level of interaction with the protein towards denaturation or stabilisation, ILs offer a unique possibility to modulate protein stabilisation or even folding events.

Let \(\mathcal{M}(\mathbb{R}^n)\) be the class of bounded away from one and infinity functions \(p:\mathbb{R}^n\to[1,\infty]\) such that the Hardy-Littlewood maximal operator is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R}^n)\). We show that if \(a\) belongs to the Hörmander class \(S_{\rho,\delta}^{n(\rho-1)}\) with \(0<\rho\le 1\), \(0\le\delta<1\), then the pseudodifferential operator \(\operatorname{Op}(a)\) is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R}^n)\) provided that \(p\in\mathcal{M}(\mathbb{R}^n)\). Let \(\mathcal{M}^*(\mathbb{R}^n)\) be the class of variable exponents \(p\in\mathcal{M}(\mathbb{R}^n)\) represented as \(1/p(x)=\theta/p_0+(1-\theta)/p_1(x)\) where \(p_0\in(1,\infty)\), \(\theta\in(0,1)\), and \(p_1\in\mathcal{M}(\mathbb{R}^n)\). We prove that if \(a\in S_{1,0}^0\) slowly oscillates at infinity in the first variable, then the condition \[ \lim_{R\to\infty}\inf_{|x|+|\xi|\ge R}|a(x,\xi)|>0 \] is sufficient for the Fredholmness of \(\operatorname{Op}(a)\) on \(L^{p(\cdot)}(\mathbb{R}^n)\) whenever \(p\in\mathcal{M}^*(\mathbb{R}^n)\). Both theorems generalize pioneering results by Rabinovich and Samko [RS08] obtained for globally log-Hölder continuous exponents \(p\), constituting a proper subset of \(\mathcal{M}^*(\mathbb{R}^n)\).

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