735 research outputs found

    Development and application of I_SUM : an index of sustainable urban mobility

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    This work describes the construction process of an Index of Sustainable Urban Mobility (I_SUM). Important aspects regarding its application as a mobility planning and management supporting tool are also discussed. The index is based on a hierarchy of criteria built essentially with data obtained from planners and technicians of eleven cities, what resulted in eighty-seven Indicators forming thirty-seven Themes, under nine Domains. Weights for the Themes and Domains were obtained through a panel of experts. A viability analysis of the index application was carried out in a city with around 220,000 inhabitants located in the state of São Paulo, Brazil. The analysis of the results has shown that a significant number of indicators could be calculated in the short term and with good quality data in the studied city. The main conclusion drawn from the application was the confirmation that I_SUM is flexible enough to be applied not only in a developing country medium-sized city, but also in cities with diverse characteristics. It is important to highlight the fact that the tool also gives the opportunity to assess the relative contribution of any specific aspects of mobility to the Social, Economic, and Environmental dimensions of sustainability. That I_SUM feature can be used to help in the formulation of either integrated or stand-alone policies per sector aiming at the development of the sustainable urban mobility. Moreover, it can help in the public participation process due to the possibility of building up scenarios based on hypothetical changes of the indicator values

    Sustainable urban mobility: a comparative study and the bases for a management system in Brazil and Portugal

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    There is a clear need for the implementation of sustainability principles and guidelines in urban areas, as well as for strategies for controlling the elements that shape the urban environment. As a consequence, indicators become essential tools in providing the knowledge and information required for understanding particular aspects and problems of the cities. Therefore, the main objective of this work was to identify indicators that are suitable for monitoring the urban mobility conditions of selected cities in Brazil and Portugal. The first step taken in order to reach that objective was the selection and analysis of mobility indicators extracted from several national and international experiences of sustainability indicators. Those indicators were organized under a framework of Categories and Themes and also submitted to the evaluation of groups of experts in both countries, in order to determine their relative importance for monitoring urban mobility conditions. The final outcome of the analysis was a common set of mobility indicators for Brazilian and Portuguese cities, in addition to a more complete list of indicators that could better serve each country in particular. © 2005 WIT Press.(undefined

    Higher Order Asymptotics of Decaying Solutions of some Generalized Burgers Equations

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    We study the large-time behavior of solutions to a generalized Burgers Equation, with initial zero mass data. Our main purpose is to present a modified version of the Renormalization Group map, which is able to provide the higher order asymptotic properties of the solution to the Cauchy problem of a class of nonlinear time-evolution problems.Comment: 25 page

    Impact of percentage and particle size of sugarcane biochar on the sorption behavior of clomazone in Red Latosol

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    Biochar is a carbonaceous material that has excellent potential as a fertilizer and soil conditioner. However, there is a lack of information concerning the effects of the amount and particle size of this pyrogenic material on the soil sorption capacity. In this work, evaluation was made of changes in clomazone (CMZ) sorption in a Red Latosol following soil conditioning using different percentages (0.25, 0.5, and 1% w/w) of sugarcane biochar in three particle sizes (<106, 106-508, and 508-610 μm). The conditioned soils presented apparent sorption coefficients (Kd) up to 1300 times higher than that of pure soil, besides changes in the behavior of CMZ sorption. The biochar particle size and percentage influenced sorption of the herbicide as well as its retention in the amended soil during desorption processes. Both sorption and desorption Freundlich constants were linearly correlated with the external surface area of the biochar present in the soil

    Schwinger multichannel method: A study of a Feshbach resonance in e-H_2 collisions

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    We present results of the application of the Schwinger multichannel method to study the role of Feshbach resonances on the elastic and electronic excitation cross sections in e-H_2 collisions. Using a ^2Σ_g^+2 resonance associated with the a ^3Σ^+_g and E^1Σ^+_g states of H_2 as an example, we quantitatively illustrate the dramatic influence of open channels on the decay of such Feshbach resonances in electron-molecule collisions

    Development and characterization of an active chitosan-based film containing quercetin

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    This work aims at developing an active chitosan film through the incorporation of quercetin and the evaluation of physical and functional properties of the films made thereof. The addition of quercetin showed to influence films properties in terms of surface morphology, tensile strength, and opacity while elongation-at-break, thickness, water vapor, and oxygen permeability were not significantly affected with incorporation of quercetin. The color parameters of chitosan films were affected by quercetin incorporation with a decrease of the values of L* and a*. The film exhibited a high free-radical scavenging activity, showing antioxidant activity. The film-forming solutions of chitosan with or without quercetin showed antibacterial activity against four Gram-negative and three Gram-positive bacteria. These results showed that quercetin incorporation in chitosan-based films has potential to be used as a solution for active food packaging.Author Marthyna Pessoa de Souza thanks the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) for fellowships. Miguel A. Cerqueira and Helder D. Silva (SFRH/BPD/72753/2010 and SFRH/BD/81288/2011, respectively) are recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE Portugal). This research was financially supported by research grants and fellowships from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), as well as the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE). The authors also thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON. 2-O Novo Norte), QREN, FEDE

    Band structure model of magnetic coupling in semiconductors

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    We present a unified band structure model to explain magnetic ordering in Mn-doped semiconductors. This model is based on the pp-dd and dd-dd level repulsions between the Mn ions and host elements and can successfully explain magnetic ordering observed in all Mn doped II-VI and III-V semiconductors such as CdTe, GaAs, ZnO, and GaN. This model, therefore, provides a simple guideline for future band structure engineering of magnetic semiconductors.Comment: 4+ pages, 5 figure

    Atividade antimicrobiana de subfrações padronizadas da planta Arrabidaea chica Verl.

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    Este estudo analisou o potencial terapêutico de extratos e subfrações padronizadas da planta amazônica Arrabidaea chica, visando seu uso tópico como medicamento e eficácia comprovada em doenças cutâneas
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