Mostrando recursos 1 - 20 de 56

  1. La educación intercultural bilingüe en la educación superior Argentina: identidades juveniles, diversidad cultural y políticas públicas

    Macarena Ossola, María; Vieira, Ricardo
    info:eu-repo/semantics/publishedVersion

  2. The decrease of NAD(P)H:quinone oxidoreductase 1 activity and increase of ROS production by NADPH oxidases are early biomarkers in doxorubicin cardiotoxicity

    Lagoa, Ricardo; Gañán, Carlos; López-Sánchez, Carmen; García-Martínez, Virginio; Gutierrez-Merino, Carlos
    info:eu-repo/semantics/publishedVersion

  3. A comparative study of alginate beads and an ion-exchange resin for the removal of heavy metals from a metal plating effluent

    Silva, Rui M. P.; Manso, João P. H.; Rodrigues, Joaquim Rui; Lagoa, Ricardo
    The capacity of dry protonated calcium alginate beads to sorb metals from an industrial effluent was studied and compared with a commercial ion-exchange resin (Lewatit TP 207). Both sorbents decreased zinc, nickel, iron and calcium concentrations in the effluent, and released sodium during treatment. Alginate beads removed lower amounts of heavy metals than the resin, but exhibited faster uptake kinetics. Zinc desorption from the sorbents was achieved in 30 minutes using 0.1 M HCl or 0.1 M H(2)SO(4). Desorption ratios with these acids varied between 90 and 100% for alginate, and 98 to 100% for the ion-exchange resin. Reusability tests...

  4. Copper ions binding in cu‐alginate gelation

    Rodrigues, Joaquim Rui; Lagoa, Ricardo
    Alginate polysaccharide forms viscous aqueous dispersions and has the ability to form gels in the presence of divalent cations such as calcium and copper. In this work, we have studied cooper ions binding during Cu‐alginate gelation, obtaining quantitative information about the amount and kinetics of cation binding. Our results indicate that copper binding during gelation occurs until a Langmuir‐type equilibrium is reached between bound and free ions in the gel‐contacting solution. The kinetics of metal ions binding can be modeled using Ritchie equation–derived models, allowing the prediction of ionic binding and gel formation temporal evolution. The ratio between cationic and...

  5. Evaluation of dry protonated calcium alginate beads for biosorption applications and studies of lead uptake

    Lagoa, Ricardo; Rodrigues, Joaquim Rui
    Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was...

  6. Evaluation of dry protonated calcium alginate beads for biosorption applications and studies of lead uptake

    Lagoa, Ricardo; Rodrigues, Joaquim Rui
    Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was...

  7. Kinetic analysis of metal uptake by dry and gel alginate particles

    Lagoa, Ricardo; Rodrigues, Joaquim Rui
    The kinetics of metal uptake by gel and dry calcium alginate beads was analysed using solutions of copper or lead ions. Gel beads sorbed metal ions faster than the dry ones and larger diffusivities of metal ions were calculated for gel beads: approximately 10−4 cm2/min vs. 10−6 cm2/min for dry beads. In accordance, scanning electron microscopy and nitrogen adsorption data revealed a low porosity of dry alginate particles. However, dry beads showed higher sorption capacities and a mechanical stability more suitable for large-scale use. Two sorption models were fitted to the kinetic results: the Lagergren pseudo-first order and the Ho...

  8. Life Stories, Cultural Metissage, and Personal Identities

    Vieira, Ricardo
    This article encompasses an underlying notion of personal identities and processes of interaction, which distinguish essentialist identity from relational identity in contexts involving subjects, fields of possibilities, and cultural metamorphosis. It addresses the idea of the individual and her/his transformations: “I am who I want to be if I can be that person.” Any one of us could hypothetically have been someone else. The question of the reconstruction of individual identities is a vital aspect in the relationship between objective social conditions and what each person subjectively does with them, in terms of auto-construction. The complexity of this question reflects...

  9. Tourism through the gaze of stakeholders: the case of Óbidos Lagoon in Portugal

    Rebelo, Cátia Filipa Cerqueira; Alves, Carlos Pedro Ferreira; Moiteiro, Gilberto Coralejo; Ezequiel, Graça Maria Gomes; Brasão, Inês Paulo Cordeiro; Vasconcelos, João Viljoen de; Carvalho, Mário João Paulo de Jesus
    Coastal lagoons are valued and sensitive ecosystems often threatened by human pressure. In our study we focused on the development of local activities in the Óbidos lagoon and we aimed to understand the stakeholders’ view about the best solutions for local development. Stakeholders were divided into residents, tourists, groups of interest and surveys and interviews were applied. The results indicated that although the lagoon is considered a dynamic economical resource for the local economy communities, tourism was identified by all stakeholders as the strategic tool for development in the lagoon. These results suggest the urgency to promote sustainable guidelines for the local tourism development.

  10. Usos e abusos do formal e não formal em educação

    Vieira, Ana Maria; Vieira, Ricardo

  11. Social professionals in school: a comparative study

    Vieira, Ana Maria

  12. Identidades, aprendizagem e mediação intercultural: uma análise antropológica

    Vieira, Ana Maria; Vieira, Ricardo

  13. Ciência, teoria social contemporânea e educação

    Vieira, Ricardo; Vieira, Ana Maria
    Os modelos científicos vigentes acabam por refletirem sempre nas práticas escolares, nas pedagogias dominantes, na educação. O objetivo principal deste ensaio é correlacionar os paradigmas científicos com os paradigmas pedagógicos e mostrar como, em parte, “somos filhos de Descartes”. Foi com ele que aprendemos o que era a ciência, o método científico, no singular, e a objetividade como valor sagrado da ciência. Foi o seu Discurso do Método que marcou a ciência do século XX e, também, a pedagogia escolar e a educação em geral. Aprendemos a pensar com a cabeça e não com o coração; desumanizamos, desantropomorfizamos a ciência, o que teve efeitos diretos na...

  14. A análise de redes sociais no estudo do processo da construção da ajuda mútua da pessoa com doença oncológica com blogue

    Damásio, Carla; Nunes, Lucília; Sobral, José Manuel
    Os recentes desenvolvimentos na saúde, sociedade e tecnologia, têm conduzido a novas formas de estar. Encarar hoje a doença oncológica (DO) é enfrentar um desafio. A comunicação, também sofreu evolução e a Internet assume um espaço crescente na sociedade. O blogue revolucionou a partilha de experiências, como é o caso da vivência da DO, podendo ser gerador de um processo de construção de ajuda mútua. Emergiu a questão: Quais os bloguitas mais ativos e dominantes numa rede de pessoas com doença oncológica com blogue? Este artigo tem como objetivos: Identificar as pessoas com DO com blogue; Identificar as pessoas mais...

  15. Avaliação da qualidade de vida infantil: O Inventário Sistémico de Qualidade de Vida para Crianças

    Fonseca, Marta
    A avaliação da qualidade de vida infantil apresenta especificidades metodológicas. O objetivo do presente estudo é analisar as características psicométricas da versão portuguesa do Inventaire Systémique de Qualité de Vie pour Enfants(ISQV-C), que assenta numa abordagem conceptual e metodológica inovadora para a autoavaliação da qualidade de vida, por ser interativo e lúdico, possuir uma psicometria que explora diversas pontuações e permitir uma análise de cada domínio de vida. Participaram do estudo 120 crianças portuguesas, dos 8 aos 12 anos de idade. Os resultados apontam para uma consistência interna satisfatória das quatro pontuações do ISQV-C (Estado, Objetivo, Importância e Qualidade de...

  16. La escuela portuguesa en el siglo XXI : autonomía y participación

    Silva, José Manuel; Silveirinha, Conceição; Rodrigues, Célia; Mineiro, João Paulo; Felício, Paulo
    En el presente artículo, se hace un análisis de la situación de la enseñanza en Portugal en este principio del siglo XXI. Se destacan las cuestiones de la autonomía de la escuela y los modelos organizativos de administración y gestión que refuerzan la participación de las familias y de la comunidad en la dirección estratégica de los centros educativos y que, además, afirman el liderazgo del director con vistas a garantizar el mejoramiento del servicio público de educación. La concreción de este modelo exige el refuerzo de la cooperación del mundo de la docencia con los ayuntamientos y otras instituciones del...

  17. The impact of polytechnic institutes on the local economy

    Alves, João; Carvalho, Luísa; Carvalho, Renato; Correia, Florbela; Cunha, Jorge; Farinha, Luís; Fernandes, Joana; Ferreira, Manuela; Lucas, Eugénio; Mourato, Joaquim; Nicolau, Ana; Nunes, Sara; Nunes, Sandra; Oliveira, Pedro; Pereira, Cristina; Pinto, Sandra; Silva, José Manuel
    Higher education institutions and, particularly, polytechnic institutes in Portugal are, generally speaking, recognised as key stakeholders in regional development. However, due to the economic recession of recent years and the consequent budget constraints, higher education institutions, now more than ever, need to demonstrate the social and cultural impact of their activities within their communities and, also, their contribution to its economic development. Thus, the aim of this paper is to estimate the economic impact of a group of polytechnic institutes located in regions with diverse socioeconomic realities, by using a common methodology. This common framework enables a comparative study and a better identification of the variables that differentiate the realities of...

  18. El proceso de elaboración del Diccionario de galicismos en el lenguaje deportivo del español peninsular (1976-2006)

    Gillain, Romain
    En esta comunicación, se explica de manera esquemática cómo se ha llevado a cabo la confección del Diccionario de galicismos en el lenguaje deportivo del español peninsular (1976-2006), objeto principal de la tesis titulada Diccionario comentado de galicismos en el lenguaje deportivo del español peninsular (1976-2006), que se presentó en la Universidad de Oviedo en enero de 2011. Antes de comenzar con la descripción del proceso de constitución del corpus lexicográfico, se especificarán los requisitos espacio-temporales y lingüísticos que cumplen los 650 elementos inventariados en esta obra de consulta y, a continuación, se detallará la metodología empleada para la identificación...

  19. Análise dos fundamentos da teoria baseada nos recursos

    Pedrosa, António José Pinto; Carvalho, Fernando
    Frequentemente as hipóteses da teoria baseada nos recursos (RBV) são testadas utilizando uma abordagem centrada na heterogeneidade dos recursos, permitindo apenas identificar que recursos ou capacidades específicas devem ser exploradas para alcançar a vantagem competitiva. Neste artigo, utilizamos uma abordagem conceptual procurando testar se as combinações de recursos e capacidades com valor, raridade e inimitabilidade, mais do que a sua especificidade, determinam maior vantagem competitiva e performance. Os resultados obtidos de 368 questionários validados por gestores de empresas de vários setores económicos portugueses corroboram as hipóteses de que, o aumento do valor, da raridade e da inimitabilidade das combinações testadas...

  20. Uncoupling techniques for the dynamic characterization of sub-structures

    Batista, F. C.; Maia, N. M. M.
    The characterization of the dynamic behavior of sub-structures may be of great importance in certain complex structures. A possible approach is through the use of uncoupling techniques. This is the subject of the present paper, where various issues are raised and different possibilities to circumvent the encountered problems are discussed. These problems are mostly due to numerical instabilities associated to the calculation procedures, namely to the ill-conditioning that often appears and causes complications in the inversion of the involved matrices. The location of the possible points of measurement may also influence the results. Several variations to the main algorithms are tried...

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