Normal Heat Conduction in a Chain with Weak Interparticle Anharmonic Potential

We analytically study heat conduction in a chain with interparticle interaction V(x)=lambda[1-cos(x)] and harmonic on-site potential. We start with each site of the system connected to a Langevin heat bath, and investigate the case of small coupling for the interior sites in order to understand the behavior of the system with thermal reservoirs at the boundaries only. We study, in a perturbative analysis, the heat current in the steady state of the one-dimensional system with weak interparticle potential. We obtain an expression for the thermal conductivity, compare the low and high temperature regimes, and show that, as we turn off the couplings with the interior heat baths, there is a "phase transition:'' the Fourier's law holds only at high temperatures

Erratum to: Designation of Natural Monuments by the Local Administration: the Example of Viana Do Castelo Municipality and its Engagement with Geoconservation (NW Portugal)

The original version of this article unfortunately contained a mistake. The four occurrences of the word “geopark” were incorrect and should be replaced with “geological park”

Overcoming inertia : drivers of the outsourcing process

Almost all managers have directly or indirectly been involved in the practice of outsourcing in recent years. But as they know, outsourcing is not straightforward. Outsourcing inertia, when companies are slow to adapt to changing circumstances that accommodate higher outsourcing levels, may undermine a firm’s performance. This article investigates the presence of outsourcing inertia and the factors that help managers overcome it. Using statistical evidence, we show that positive performance effects related to outsourcing can accumulate when circumstances change. This is then followed by rapid increases in outsourcing levels (i.e. outsourcing processes). We investigate what gives rise to these outsourcing processes through follow-up interviews with sourcing executives, which suggest five drivers behind outsourcing processes: managerial initiative (using outside experience); hierarchy (foreign headquarters); imitation (of competitors and of similar firms); outsider advice (from external institutions); knowledge sources (using external information). These five drivers all offer scope for managerial action. We tie them to academic literatures and suggest ways of investigating their presence and impact on the outsourcing process. Overall, we conclude that while economizing factors play a key role in explaining how much firms outsource, it is socializing factors that tend to drive outsourcing processes

Effectt of Supplements on Forage Degradability of \u3ci\u3eBrachiaria brizantha\u3c/i\u3e cv. Marandu Grazed by Steers

The supplementation effect was evaluated using crossbred rumen-fistulated steers maintained in a Brachiaria brizantha cv. marandu pasture. The animals received energy supplementation (corn-COR); low degradability protein supplementation (corn gluten-GLU); and high degradability protein supplementation (soybean-SBM) at two levels N1 (± 0.5 kg/an/day) and N2 (± 1.5 kg/an/day); or no supplementation (Control). The factorial (3x2), plus the control, was studied according to complete randomized block design with three replications. The supplementation did not affect (P\u3e 0.05) the potential degradability (POD), the effective degradability (EFD), and the degradation rates (DR) of the forage (extrusa). The GLU supplementation provided higher (P\u3c 0.05) EFD of the NIDN fraction than the SBM, and both did not differ (P\u3e 0.05) of the COR treatment. The data allowed to conclude that the supplementation used did not provide alterations in the forage degradability, probably due to the low N-NH3 level and the non-variation of the ruminal pH

Alocação estratégica igualmente ponderada e fundos balanceados

Results and contribution of the article: Equally weighted strategic allocation portfolios have higher cumulative returns than selected balanced funds. However, the average returns are not always statistically greater than those of funds and the statistical significance of a portfolio changes according to the sub-period analyzed. Fixed-income portfolios were the only ones to outperform funds more frequently. Funds, in turn, fail in active management and perform worse than portfolios weighted according to their declared passive allocation. Equally weighted portfolios only outperformed balanced funds because they deviated from their investment policy. Transaction costs and different portfolio rebalancing frequencies do not change the conclusions.Resultados e contribuições: carteiras de alocação estratégica apresentam retornos acumulados mais elevados do que fundos balanceados selecionados. Contudo, os retornos médios nem sempre são estatisticamente maiores do que os dos fundos e a significância estatística de uma carteira muda conforme o subperíodo analisado. Carteiras somente com renda fixa foram as que superaram os fundos com mais frequência. Os fundos, por sua vez, fracassam na gestão ativa e se saem pior do que carteiras ponderadas segundo a política de alocação que eles declaram. As carteiras igualmente ponderadas só superaram os fundos balanceados porque eles se desviaram de sua política de investimentos. Os custos de transação e diferentes frequências de rebalanceamento das carteiras não mudam as conclusões

Projeto e desenvolvimento da arquitetura de um robô agrícola móvel

Parameters such as tolerance, scale and agility utilized in data sampling for using in Precision Agriculture required an expressive number of researches and development of techniques and instruments for automation. It is highlighted the employment of methodologies in remote sensing used in coupled to a Geographic Information System (GIS), adapted or developed for agricultural use. Aiming this, the application of Agricultural Mobile Robots is a strong tendency, mainly in the European Union, the USA and Japan. In Brazil, researches are necessary for the development of robotics platforms, serving as a basis for semi-autonomous and autonomous navigation systems. The aim of this work is to describe the project of an experimental platform for data acquisition in field for the study of the spatial variability and development of agricultural robotics technologies to operate in agricultural environments. The proposal is based on a systematization of scientific work to choose the design parameters utilized for the construction of the model. The kinematic study of the mechanical structure was made by the virtual prototyping process, based on modeling and simulating of the tension applied in frame, using the.Parâmetros, como tolerância, escala e agilidade empregados na amostragem de dados para uso em Agricultura de Precisão, exigem um expressivo número de pesquisas no desenvolvimento de instrumentos e técnicas para automação. Destacam-se a utilização de metodologias em sensoriamento remoto utilizadas em conjunto com o Sistema de Informação Geográfica (SIG), adaptados ou desenvolvidos para o uso agrícola. Visando a isso, a aplicação de Robôs Agrícolas Móveis é uma forte tendência, principalmente na União Europeia, EUA e Japão. No Brasil, pesquisas são necessárias para o desenvolvimento de plataformas robóticas, que sirvam de base para sistemas de navegação autônomos ou semiautônomos. O objetivo deste trabalho é descrever o projeto de uma plataforma experimental para a aquisição de dados em campo para o estudo da variabilidade espacial e desenvolvimento de tecnologias para operação de robôs em ambiente agrícola. A proposta baseia-se em uma sistematização de trabalhos científicos que norteiam a escolha dos parâmetros de projeto utilizados para a construção do modelo. O estudo cinemático da estrutura mecânica foi feito pelo processo de prototipagem virtual, baseado na modelagem e simulação das tensões aplicadas no chassi, utilizando o método dos elementos finitos, em função dos conceitos básicos de cinemática de robôs móveis e experiências em trabalhos anteriores.(FAPESP) São Paulo Research Foundation(CNPq) National Council of Scientific and Technological Developmen

Electrotechnologies applied to microalgal biotechnology Applications, techniques and future trends

Electrotechnologies are based on the direct application of an external electric field through a given semi-conductive material. These technologies are part of a wide range of biotechnological processes, considered cost-effective and environmentally-friendly in view of the less intensive use of non-renewable resources and high levels of energetic efficiency. In this regard, electrotechnologies are a promising processing tool to overcome some of the microalgae's exploitation limitations. The application of electric field-based techniques can cover upstream (i.e. electroporation for genetic transformation, inactivation of culture contaminants, and improvement of growth kinetics) and downstream processes (e.g. harvesting and extraction methods). Pulsed electric fields (PEF) and moderate electric fields (MEF), targeted at microalgae cellular permeabilization and subsequent extraction of valuable compounds, count with a substantial body of fundamental research which puts them on the front row to become mainstream techniques in a near future. This review provides comprehensive knowledge systematization of the current status of the direct application of these techniques on microalgal biotechnology, as wells as future trends and challenges regarding developments in electrotechnologies to be applied to microalgae industrial exploitation.Thisresearch workwas supported by theGrants SFRH/BPD/98694/ 2013 (Bruno Fernandes), SFRH/BD/110723/2015 (Rui Rodrigues), SFRH/BPD/81887/2011 (Ricardo Pereira) and SFRH/BD/52335/2013 (Pedro Geada) from Fundação para a Ciência e a Tecnologia (Portugal). Luís Loureiro is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-FEDER-006684), Project UID/Multi/04423/2013, Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), FCT Strategic Project of UID/BIO/04469/2013 unit, by the project NOVELMAR (reference NORTE-01-0145-FEDER-000035), co-financed by the North Portugal Regional Operational Programme (Norte 2020) under the National Strategic Reference Framework (NSRF), through the ERDF and by BioTecNorte operation (NORTE-01-0145-FEDER 000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Impact of composition and morphology on the optical properties of Si-NC/P3HT thin films processed from solution

Blends of Si nanocrystals (Si-NCs) and organic semiconductors are promising materials for new optical and electronic devices processed from solutions. Here, we study how the optical properties of composite films containing Si-NCs and the organic semiconductor poly(3-hexylthiophene) (P3HT) are influenced by the composition and morphology resulting from different solution-processing parameters and different solvents used dichlorobenzene vs. chloroform). The optical spectra of the hybrid films are described using a simple phenomenological model, with which we can discern the contribution of each material in the films to the optical properties. From this analysis, we obtain quantitative information about the composition and morphology of the hybrid nanostructured films, which otherwise would be obtained from more demanding microscopy and spectroscopy techniques. For the case of the Si-NC/P3HT blend, we find that in films deposited from dichlorobenzene solutions the Si-NCs contribute sizably to light absorption.This work was funded by FCT/I3N via the HybridSolar project, by the DFG via Teilprojekt B2 and by the European Union and the Ministry of Innovation, Science and Research of the German State of North Rhine-Westphalia in the framework of an Objective 2 Programme (European Regional Development Fund, ERDF). Funding is also acknowledged from the Portuguese Foundation for Science and Technology (FCT) through the Projects Nos. PTDC/FIS/112885/2009 and PEst-C/CTM/LA0025/2011 and via the Strategic Project LA 25:2011-2012

Mechanical properties of Graphene Nanoribbons

Herein, we investigate the structural, electronic and mechanical properties of zigzag graphene nanoribbons upon the presence of stress applying Density Functional Theory within the GGA-PBE approximation. The uniaxial stress is applied along the periodic direction, allowing a unitary deformation in the range of +/- 0.02%. The mechanical properties show a linear-response within that range while the non-linear dependence is found for higher strain. The most relevant results indicate that Young's modulus is considerable higher than those determined for graphene and carbon nanotubes. The geometrical reconstruction of the C-C bonds at the edges hardness the nanostructure. Electronic structure features are not sensitive to strain in this linear elastic regime, being an additional promise for the using of carbon nanostructures in nano-electronic devices in the near future.Comment: 30 pages. J. Phys.: Condens. Matter (accepted