1,112 research outputs found

    Quantum walks in two dimensions: controlling directional spreading with entangling coins and tunable disordered step operator

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    We study a 2-D disordered time-discrete quantum walk based on 1-D `generalized elephant quantum walk' where an entangling coin operator is assumed and which paves the way to a new set of properties. We show that considering a given disorder in one direction, it is possible to control the degree of spreading and entanglement in the other direction. This observation helps assert that the random quantum walks of this ilk serve as a controllable decoherence channel with the degree of randomness being the tunable parameter and highlight the role of dimensionality in quantum systems regarding information and transport.Comment: 16 pages, 19 figure

    Quantum walks with spatiotemporal fractal disorder

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    We investigate the transport and entanglement properties exhibited by quantum walks with coin operators concatenated in a space-time fractal structure. Inspired by recent developments in photonics, we choose the paradigmatic Sierpinski gasket. The 0-1 pattern of the fractal is mapped into an alternation of the generalized Hadamard-Fourier operators. In fulfilling the blank space on the analysis of the impact of disorder in quantum walk properties -- specifically, fractal deterministic disorder --, our results show a robust effect of entanglement enhancement as well as an interesting novel road to superdiffusive spreading with a tunable scaling exponent attaining effective ballistic diffusion. Namely, with this fractal approach it is possible to obtain an increase in quantum entanglement without jeopardizing spreading. Alongside those features, we analyze further properties such as the degree of interference and visibility. The present model corresponds to a new application of fractals in an experimentally feasible setting, namely the building block for the construction of photonic patterned structures.Comment: 16 pages, 9 figure

    The role of process variables in the design of multiproduct batch protein production plants

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    This work reports findings about the role of process variables in the design of multiproduct batch plants. Unlike continuous processes, batch processes are subject to size and time constraints which depend on the structure of the plant: the number of units at each stage and the provision of intermediate storage. We used simple process performance models (yet involving all the process variables with significant economic impact) to get explicit expressions for these size and time factors. The traditional approach uses fixed size and time factors. So the addition of those expressions to the original fixed factors model, permitted to simultaneously optimize the plant structure and process variables, and study the role of the latter in the design. We found that if the plant structure constraints are disregarded (with a Free Unlimited Storage operating policy), process variables behave just alike in continuous processes. They trade off cost components with the Total Annual Cost being quite insensitive to them in the neighborhood of the optimal solution. As setting the process variables sets the size and time factors, this means that near the optimal set of process variables, cycle times and size factors can be accommodated to the plant structure, with little effect on the cost of equipment.Fil: Montagna, Jorge Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Vecchietti, Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Iribarren, Oscar Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Pinto, José M.. Universidade de Sao Paulo; BrasilFil: Asenjo, Juan A.. Universidad de Chile; Chil

    MÉTODOS DE EFICIÊNCIA ENERGÉTICA E DE MITIGAÇÃO DE EMISSÕES DE GASES POLUENTES PARA NAVIOS E OS IMPACTOS NO SETOR DE TRANSPORTE MARÍTIMO

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    O presente artigo apresenta e categoriza, em 6 grupos de atuação, as diversas técnicas e métodos que vem sendo utilizados e desenvolvidos em todo o mundo para a redução de emissões de gases poluentes provenientes da exaustão de Navios. A utilização e combinação destas técnicas são apontadas como indispensáveis para o cumprimento das metas da Organização Marítima Internacional (IMO) para 2050 e já definem novos parâmetros para os futuros e atuais projetos de Navios, fortalecendo cada vez mais o conceito de “GreenShips”. No entanto a aplicação destas técnicas de mitigação geram impactos consideráveis no comércio marítimo. Alguns destes impactos são abordados e discutidos neste artigo.

    Impact is a Gcn2 inhibitor that limits lifespan in caenorhabditis elegans

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The General Control Nonderepressible 2 (GCN2) kinase is a conserved member of the integrated stress response (ISR) pathway that represses protein translation and helps cells to adapt to conditions of nutrient shortage. As such, GCN2 is required for longevity and stress resistance induced by dietary restriction (DR). IMPACT is an ancient protein that inhibits GCN2. Results: Here, we tested whether IMPACT down-regulation mimics the effects of DR in C. elegans. Knockdown of the C. elegans IMPACT homolog impt-1 activated the ISR pathway and increased lifespan and stress resistance of worms in a gcn-2-dependent manner. Impt-1 knockdown exacerbated DR-induced longevity and required several DR-activated transcription factors to extend lifespan, among them SKN-1 and DAF-16, which were induced during larval development and adulthood, respectively, in response to impt-1 RNAi. Conclusions: IMPACT inhibits the ISR pathway, thus limiting the activation of stress response factors that are beneficial during aging and required under DR.The General Control Nonderepressible 2 (GCN2) kinase is a conserved member of the integrated stress response (ISR) pathway that represses protein translation and helps cells to adapt to conditions of nutrient shortage. As such, GCN2 is required for longev141115CNQP - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)444424/2014-8474397/2011-42010/52557-02015/01316-72015/04264-82012/24490-42009/52047-52014/17145-42012/04064-02014/25068-02014/25270-32014/10814-8We thank Dr. T. Keith Blackwell and Dr. David Ron for providing the Patf-

    Overview of phlorotannins’ constituents in Fucales

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    Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020. Thanks to PTDC/BAA-AGR/31015/2017, “Algaphlor—Brown algae phlorotannins: From bioavailability to the development of new functional foods”, co-financed by the Operational Programme for Competitiveness and Internationalization— POCI, within the European Regional Development Fund (FEDER), and the Science and Technology Foundation (FCT), through national funds. Silva S. thanks FCT for funding through program DL 57/2016–Norma transitória (Ref. SFRH/BPD/74299/2010)

    Enhancing entanglement with the generalized elephant quantum walk from localized and delocalized states

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    Quantum walks are paradigmatic models for studies spanning from fundamental properties of quantum theory to realizations of quantum algorithms. For many years, a plethora of important results based on such models appeared in literature. Recently, a quantum walk with a nonstandard step operator was proposed and named the elephant quantum walk (EQW). With proper statistical distribution for the steps, the generalized EQW (gEQW) can be programmable to exhibit a myriad of dynamical behavior ranging from diffusion and superdiffusion to ballistic and hyperballistic spreading. Such a rich phenomenology makes the gEQW a promising model. In this work we study the influence of the statistics of the step size and the delocalization of the initial states on the entanglement entropy of the coin. Our results show that the gEQW generates maximally entangled states for almost all initial coin states and coin operators considering initially localized walkers and for the delocalized ones, taking the proper limit, the same condition is guaranteed.Comment: 11 pages, 10 figure

    Estrategia para el desarrollo del terminal portuario de Paita

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    El gran crecimiento del comercio mundial ha convertido al transporte y la infraestructura que lo soporta en elementos cada vez m?s relevantes para el progreso econ?mico de las naciones. La mayor parte del tr?fico mundial de carga se realiza por la v?a mar?tima, lo cual ha demandado una serie de transformaciones en la industria portuaria que, con el fin de adecuarse a las nuevas demandas, se ha visto obligada a desarrollar infraestructura, procesos, equipos y tecnolog?a especializada, gr?as, muelles y patios, as? como tecnolog?as de informaci?n. Frente a esta realidad, es importante que el Per? se esfuerce por mejorar los niveles de eficiencia de sus puertos en busca de mayor competitividad. Un puerto con este potencial es el Terminal Portuario de Paita (localizado en el departamento de Piura) porque se conecta directamente con departamentos de la costa, sierra, lo cual abre una posibilidad de comercio con el Brasil. El objetivo de esta investigaci?n es identificar una estrategia de desarrollo para este puerto mediante el aprovechamiento de sus oportunidades y la reducci?n de sus puntos d?biles. Para ello se ha realizado un estudio de la situaci?n actual del puerto y se le ha comparado con los cuatro puertos m?s destacados de Sudam?rica: Valpara?so (Chile), San Antonio (Chile), Cartagena (Colombia) y Guayaquil (Ecuador)

    Bis(tetra­phenyl­phospho­nium) bis­[N-(trifluoro­methyl­sulfon­yl)dithio­carbimato(2−)-κ2 S,S′]zincate(II)

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    The title salt, (C24H20P)2[Zn(C2F3NO2S3)2], consists of a complex dianion and two tetra­phenyl­phospho­nium cations. The ZnII ion displays a distorted tetra­hedral coordination environment with four S atoms from two S,S′-chelated N-(trifluoro­methyl­sulfonyl­)dithio­carbimate anions. In the crystal, besides the ionic inter­action of the oppositely charged ions, inter­molecular C—H⋯O inter­actions between cations and anions are observed. One of the cations inter­acts with an inversion-related equivalent by π–π stacking between phenyl rings, with a centroid–centroid distance of 3.932 (4) Å

    The Sao Paulo Lightning Mapping Array (SPLMA): Prospects to GOES-R GLM and CHUVA

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    This paper presents the characteristics and prospects of a Lightning Mapping Array to be deployed at the city of S o Paulo (SPLMA). This LMA network will provide CHUVA campaign with total lightning, lightning channel mapping and detailed information on the locations of cloud charge regions for the thunderstorms investigated during one of its IOP. The real-time availability of LMA observations will also contribute to and support improved weather situational awareness and mission execution. For GOES-R program it will form the basis of generating unique and valuable proxy data sets for both GLM and ABI sensors in support of several on-going research investigation
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