893 resultados para Research Subject Categories::SOCIAL SCIENCES::Social sciences::Sociology
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Paper based on the text to be published in Moniz, A.B. and Okuwada, K. (2016), Technology Assessment in Japan and Europe, Karlsruhe, KIT Scientific Publishing
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As questões ligadas às desonerações tributárias como fomento ao desenvolvimento do país vêm ganhando muita importância e destaque no cenário político e econômico brasileiro. Sendo assim, este estudo de caso fictício tem como objetivo promover uma reflexão acerca dos fatores que sejam relevantes para a desoneração da cadeia produtiva do pescado e atingir objetivos educacionais expondo aos estudantes às interdependências e consequências ao longo do processo. O caso também pretende promover uma discussão sobre as ações gerenciais apropriadas, com utilização de ferramentas de planejamento para orientar tomadas de decisões e, para tanto, apresenta alguns fatores facilitadores e obstáculos, bem como benefícios alcançados, que são impactados por múltiplos fatores. Dentro dos parâmetros estabelecidos, as conclusões levam ao entendimento de que a solução mais indicada seria a de trabalhar na desoneração e mais especificamente nas rações do pescado, que, com a redução dos custos, proporcionaria mais demanda, maior produção, mais investimentos em tecnologia, mais formalização da economia e tantos outros benefícios econômicos e sociais.
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Hay una amplia tradición de investigación que nos dice que las y los docentes desarrollan saberes propios, apropiados para enseñar. Esa tradición no ha tenido en cuenta la diferencia de ser maestra y de ser maestro como una fuente de sentido, como algo significativo. Eso es lo que hace la investigación –tanto de académicas como de maestras– generada en el ámbito de la pedagogía de la diferencia sexual. Una investigación que nombra y da valor a la experiencia femenina en la escuela, en la educación, capaz de crear un conocimiento teórico no abstracto, no desvinculado de la experiencia, que puede y debe ser el referente fundamental tanto para la propia práctica como para la formación de las futuras maestras, de los futuros maestros. La presencia de las mujeres en la escuela es una riqueza. Reconocer y nombrar sus saberes es necesario y urgente, porque son reales y porque prestan atención a dimensiones fundamentales para el desarrollo de la vida de cada criatura, y para la vida social. Saberes que priorizan lo vivo (en vez de lo abstracto), la relación (y no la competitividad y el enfrentamiento), el amor (frente a la indiferencia), la política primera (la palabra antes que la norma), la relación sin fin (en lugar de la relación instrumental).
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Link to article on publisher site: https://www.press.jhu.edu/journals/portal_libraries_and_the_academy/portal_pre_print/articles/belanger.pdf
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Aerosol size distributions from the Mt. Bachelor Observatory for 7/30/2015 to 9/23/2015.
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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 and McKay pseudo-second order equations. The former was found to be the most adequate to model metal uptake by dry alginate beads and kinetic constants in the orders of 10−3 and 10−2 min−1 were obtained for lead solutions with concentrations up to 100 g/m3. The pseudo-first order model was also found to be valid to describe biosorbent operation with a real wastewater indicating that it can be used to design processes of metal sorption with alginate-based materials.
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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 the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.
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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 the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.
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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 polysaccharide quantities in the gelation system determines the kinetics of gelation and the characteristics of the gel formed. The experimental results and models applied in the work give more insights on alginate gelation and contribute to a reliable design and control of production methods for alginate gel structures.