Electronic Structure and Half-Metallic Character in Sr2CoB′O6 (B′ = Mo, Re) Materials

We report several ab initio calculations performed for Sr₂CoB′O₆ (B′ = Mo, Re) by means of the Density Functional Theory and the Linearized Augmented Plane Waves method with spin polarization. For the calculations, the exchange and correlation potentials were included through the local density LDA+U approximation with B3PW91. Density of states (DOS) study was carried out considering both up and down spin polarizations by the Generalized Gradient Approximation (GGA). From the Murnaghan state equation, we calculate the cell dimensions that minimize the total energy. Our results of DOS calculations show that the Sr₂CoMoO₆ material presents a metallic behavior, while Sr₂CoReO₆ reveals a half-metallic nature with conductor behavior for the spin down orientation and semiconducting feature for spin up channel. It was observed close to Fermi level that the low-energy spin down states of Co are responsible by the majority contribution to conduction band. The calculated effective cell magnetic moment of the Sr₂CoReO₆ compound evidences a value 2.02 μ _B , which is close to an integer number as expected for a half-metallic material.     

Nanostructured metal oxides obtained by means polymerization-combustion at low temperature for CO selective oxidation

We investigated the synthesis of nanosized Co₃O₄, NiO and CuO oxides by the polymerization-combustion method and evaluated in the selective oxidation of CO. These materials were characterized before and after catalytic test under specific conditions by X-ray diffraction, scanning electron microscopy, temperature programmed reduction, Raman spectroscopy and Diffuse reflectance infrared Fourier transform spectroscopy. For isoconversion the activity follows the order: Co₃O₄>NiO > CuO. The intrinsic activities under isothermal conditions at 100 °C are: 0.20 × 10⁻³ s⁻¹ for the Co₃O₄ and 0.08 × 10⁻³ s⁻¹ for NiO and CuO. Therefore, the activity of the Co₃O₄, is 3 times higher than for NiO and CuO. The XRD and Raman analyses after catalytic test confirm the existence of a partial reduction of oxides to the metallic phase and no evidence of carbon deposition over surface materials. In the case of nickel oxide the analyzed sample shows the metallic phase of nickel and in the case of copper oxide the sample presents a high grade of reduction. XRD results confirm the presence of Cu₂O and metallic Cu. Finally, results showed that these oxide catalysts present a high resistance to carbonaceous formation under present reaction conditions and confirm the effectiveness of polymerization-combustion technique for synthesis of active high catalyst in the selective oxidation of CO.     

Nutritional behavior of cyclists during a 24-hour team relay race: a field study report

Background  

Information about behavior of energy intake in ultra-endurance cyclists during a 24-hour team relay race is scarce. The nutritional strategy during such an event is an important factor which athletes should plan carefully before the race. The purpose of this study was to examine and compare the nutritional intake of ultra-endurance cyclists during a 24-hour team relay race with the current nutritional guidelines for endurance events. Additionally, we analyzed the relationship among the nutritional and performance variables.     

Structural and Magnetic Properties of the New La2SrCo2FeO9 Triple Perovskite

In this work, we report synthesis and characterization of the new La₂SrCo₂FeO₉ triple perovskite material. The samples were produced by the solid-state reaction method. The analyses of the XRD patterns were made by Rietveld refinement through the GSAS code. The results reveal that the material crystallizes in an orthorhombic complex perovskite, space group Immm (#71) with lattice parameters a=5.4314(3) ?, b=5.4583(3) ? and c=7.7018(2) ?. SEM micrographs evidence a strongly diffused granular morphology with mean grain size of 2 μm and the EDX spectra show that the chemical composition of samples are in good agreement with the nominal values of the stoichiometric formula. ⁵⁷Fe Mössbauer spectroscopy recorded at 300 K reveals two sites in concordance with the X-ray diffraction measurements, and its valence state is +3, as determined from the isomer shift found. At 4.2 K magnetic ordering with canting of the Fe moments is found. Measurements of the magnetization as a function of temperature permitted us to determine the ferromagnetic characteristic of material with an effective magnetic moment of 9.7μ _B.     

Physically Based Simulation and Rendering of Urban Thermography

Urban thermography is a non-invasive measurement technique commonly used for building diagnosis and energy efficiency evaluation. The physical interpretation of thermal images is a challenging task because they do not necessarily depict the real temperature of the surfaces, but one estimated from the measured incoming radiation. In this sense, the computational rendering of a thermal image can be useful to understand the results captured in a measurement campaign. The computer graphics community has proposed techniques for light rendering that are used for its thermal counterpart. In this work, a physically based simulation methodology based on a combination of the finite element method (FEM) and ray tracing is presented. The proposed methods were tested using a highly detailed urban geometry. Directional emissivity models, glossy reflectivity functions and importance sampling were used to render thermal images. The simulation results were compared with a set of measured thermograms, showing good agreement between them.     

Proving the efficiency of template matching-based markerless tracking methods which consider the camera perspective deformations

Template matching techniques are often used for camera tracking. They provide a good balance between computational cost and robustness to illumination changes. However, they lack robustness to camera orientation and scale changes. Camera movement, and specially rotation, generates perspective deformations that affect the process of patch matching, so the number of inliers (3D–2D correspondences) decreases. This fact affects camera tracking stability. This paper provides the following statistical proof: considering surface normals associated with 3D points substantially increases the number of inliers. So, this paper shows that computing perspective compensation improves the tracking. For instance, in a particular camera path used for experiments in this paper, without compensation, only a \(14\%\) of 3D points projected into the image were found as inliers, while perspective compensation increased that figure up to a \(65\%\). These results must be contextualized in the analysis provided by the paper.     

A biased‐randomized metaheuristic for the capacitated location routing problem

The location routing problem (LRP) involves the three key decision levels in supply chain design, that is, strategic, tactical, and operational levels. It deals with the simultaneous decisions of (a) locating facilities (e.g., depots or warehouses), (b) assigning customers to facilities, and (c) defining routes of vehicles departing from and finishing at each facility to serve the associated customers’ demands. In this paper, a two‐phase metaheuristic procedure is proposed to deal with the capacitated version of the LRP (CLRP). Here, decisions must be made taking into account limited capacities of both facilities and vehicles. In the first phase (selection of promising solutions), we determine the depots to be opened, perform a fast allocation of customers to open depots, and generate a complete CLRP solution using a fast routing heuristic. This phase is executed several times in order to keep the most promising solutions. In the second phase (solution refinement), for each of the selected solutions we apply a perturbation procedure to the customer allocation followed by a more intensive routing heuristic. Computational experiments are carried out using well‐known instances from the literature. Results show that our approach is quite competitive since it offers average gaps below 0.4% with respect to the best‐known solutions (BKSs) for all tested sets in short computational times.     

A Split-Based Incremental Deterministic Automata Minimization Algorithm

We here study previous results due to Hopcroft and Almeida et al. to propose an incremental split-based deterministic automata minimization algorithm whose average running-time does not depend on the size of the alphabet. The experimentation carried out shows that our proposal outperforms the algorithms studied whenever the automata have more than a (quite small) number of states and symbols.     

Immunomodulating capacity of kefir

Kefir is a fermented milk produced by the action of lactic acid bacteria, yeasts and acetic acid bacteria, trapped in a complex matrix of polysaccharides and proteins. Beyond its inherent high nutritional value as a source of proteins and calcium, kefir has a long tradition of being regarded as good for health in countries where it is a staple in the diet. However, published human or animal feeding trials to substantiate this view are not numerous. The aim of this work was to determine the immunomodulating capacity of kefir on the intestinal mucosal immune response in mice and to demonstrate the importance of dose and cell viability on this response. BALB/c mice were fed with commercial kefir ad libitum (diluted 1/10, 1/50, 1/100 or 1/200) or pasteurized kefir (diluted 1/6, 1/10, 1/50, 1/100) for 2, 5 or 7 consecutive days. At the end of each feeding period, the bacterial translocation assay was performed in the liver. Small intestine structure was studied by haematoxilin-eosin staining and light microscopy. The number of IgA+ and IgG+ cells was also determined. For the functional doses chosen, cytokines (IL-2, IL-4, IL-6, IL-10, IL-12, TNF-alpha and IFN-gamma) were determined. Kefir and pasteurized kefir were able to modulate the mucosal immune system in a dose-dependent manner. Kefir was administred 10-times more diluted than pasteurized kefir, but it induced an immunomodulation of similar magnitude, indicating the importance of cell viabilty. The results suggest that a Th1 response was controlled by Th2 cytokines induced by kefir feeding. Pasteurized kefir would induce both Th2 and Th1 responses. This is the first study in vivo regarding the mechanisms involved in the immunomodulating capacity of the oral administration of kefir containing viable or heat-inactivated bacteria at different doses.