44,644 research outputs found
Estudo da adsorção de cobre (II) usando como adsorvente pó da casca de coco verde ativada com hidróxido de sódio
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Química.A poluição por metais pesados vem se tornando um sério problema ambiental. O uso de biomassas como adsorvente para a remoção de metais tóxicos de efluentes industriais aparece como uma alternativa promissora às tecnologias existentes. Dentro deste contexto surge a casca de coco verde, que pode ser utilizada como adsorvente apresentando como uma vantagem o baixo custo do material. O objetivo deste trabalho de conclusão de curso foi determinar a capacidade de adsorção de cobre (II) pela casca de coco verde tratada com NaOH 0,1 mol L-1. No processo de adsorção foram avaliados o efeito do pH na adsorção, o mecanismo cinético de adsorção, o equilíbrio de adsorção, e a dessorção do metal. Observou-se que a adsorção de cobre (II) é dependente do pH da solução e a quantidade máxima adsorvida ocorreu em pH 6,0. O estudo cinético revelou que o equilíbrio foi atingido em 9 horas. Os modelos cinéticos de pseudo primeira-ordem, pseudo segunda-ordem e difusão intrapartícula, em suas formas linearizadas, foram testados para avaliar o mecanismo cinético que controla o processo de adsorção. Verificou-se que o modelo de pseudo segunda-ordem foi o que melhor correlacionou os dados experimentais. Obtiveram-se boas percentagens de remoção para o cobre (II), sendo que, em concentrações inicias inferiores a 100 mg g-1 foram obtidas percentagens de remoção entre 40 a 96,1%. Para a interpretação dos dados de equilíbrio de adsorção, foram utilizados os modelos de isoterma de Langmuir e Freundlich. A análise dos resultados permitiu concluir que o modelo de isoterma de Langmuir forneceu o melhor ajuste dos dados experimentais para o sistema estudado. A capacidade máxima de adsorção (qm ) observada para o adsorvente foi de 13,04 mg g-1. O estudo de dessorção do íon metálico cobre (II), foi realizado com soluções eluentes de HNO3 e EDTA em diferentes concentrações, e revelou que a melhor performance de dessorção de cobre (II) ocorreu com solução de EDTA. Os resultados apresentados mostram que a casca de coco verde apresenta as características apropriadas para o processo de adsorção de cobre (II) e que pode ser utilizada como uma alternativa de descontaminação de efluentes
A Guide to CoCo
No full textCoCo is a program for estimation, test and model search among hierarchical interaction models for large complete contingency tables. The name CoCo is derivated of "Co"mplete "Co"ntingency tables, since the initial program could only handle complete tables, but the program has been enhanced to handle incomplete tables. CoCo works especially efficiently on graphical models, and some of the commands are designed to handle graphical models.
The Effect of Morphometry, Land-Use and Lithology on Landslides Susceptibility: An Exploratory Analysis
No full textGIS features provide simple and useful tools for landslides susceptibility and hazard studies, allowing the identification and the quantification of predisposing factors, and their relative importance. In lithologically homogeneous areas, the most influent factor of landslides is slope morphometry, in particular inclination, height and form. Moreover, within a hydrographic basin, landslides are coupled with drainage network. In fact landslides density and drainage density are positively correlated. Furthermore, human activity strongly influences the development of landslides. In our previous works, we introduced MSI (Morphometric Slope Index) as general index for slope morphometry, combining the main linear and areal morphometric features (area, form, length, inclination, width). Its formula is: MSI=A3D/A2D·L·Rc (where A3D is the three-dimensional area of the slope, A2D is its plan area, L is the slope length and Rc is the circularity ratio). We tested MSI as driver of different erosion landforms, demonstrating its influence in determining, on the one hand, the development and the final arrangement of calanchi drainage network (the typical Italian badlands), and, on the other hand, the erosion processes within them, mainly gullies and landslides. The present study is an exploratory application of this index to landslides susceptibility, aimed to analyze the combined effect of slope morphometry (summarized in MSI), lithology and land-use on the distribution of landslides in small catchments. The study is located in the Italian periadriatic foredeep, in the Abruzzo Region. This study has reinforced our perspective about the validity of the application of the techniques of geomorphometric analysis to the landslides susceptibility. Especially we consider this approach an efficient tool to summarize different controlling factors
INVENTORY AND CHARACTERIZATION OF SICILIAN BADLANDS
No full textThe United Nations Convention to Combat Desertification (UNCCD, 1994) addressed desertification as a global problem defining it as “land degradation in arid, semi-arid, and dry sub-humid areas, resulting from various factors, including climate variations and human activity”. In the Mediterranean areas, this phenomenon results from the interaction of various factors such as climate, lithology, vegetation and land use. The study of the predisposing factors allows the time/space assessment of the phenomenon and a continuous field monitoring allows to quantify the data in terms of vulnerability degree and to develop decision-making tools for integrated land use planning. One of the most fragile ecosystems are the badlands areas in Sicily. Their geological and climatic features (erosive rocks and marginal soils, and highly variable rainfall) and often a negative human impacts (inadequate land use and agricultural practices) led to increasing soil erosion and vegetation degradation, predisposing the terrain to the badlands. Moreover, the slope topography can be considered as a driver factor for the inception and the evolution of the badlands, in particular if we considered the badlands as miniature drainage systems, fully comparable to small river basins.
The present work focused on the role of the pre-incision slope topography on the typologies and characteristics of the Sicilian badlands. The badlands areas of the entire Sicily were mapped in order to create an inventory of landforms based on morphological criteria. The digital orthophotos (2007-2008) at a nominal scale of 1:10.000 available in the WebGIS server of the Regione Sicilia and the Google Earth images of the same periods were closely examined. The landforms were digitized as polygons by means of a GIS software and recorded into a geo-database. The channel networks of each badland were traced and their drainage density (D) were calculated. The numbers of furrows directly tributary to the external drainage network were measured by using the index Gully Tributary (GT). This allowed to distinguish two typologies of badlands drainage pattern: dendritic for GT=1 (with only one main furrow) and parallel for GT>1 (with several parallel furrows). For each landform, the pre-erosion topography was reconstructed by filling the incision, using the heights of the watershed divide as point values in a topography interpolation tool in GIS. It represented the slope topography prior to the development of the current drainage network. The pre-incision slope morphometry of each landform was characterized by calculating the Morphometric Slope Index (MSI) considered as general index for slope morphometry. MSI, GT and D were compared via statistics in order to detect the influence of pre-erosion slope morphometry on the typology and the arrangement of the badlands drainage networks
O Ambiente cantado e contado pelos brincantes de coco de roda e ciranda da Paraíba
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação. Programa de Pós-Graduação em EducaçãoEsta pesquisa buscou outros modos de ver e narrar o ambiente. Através de entrevistas, história oral e registros em audiovisual, busquei perceber como o ambiente é contado e cantado por brincantes de duas manifestações populares da Paraíba - o coco de roda e a ciranda. Para a realização do trabalho de campo visitei brincantes pertencentes a comunidades quilombolas, tanto no interior do estado quanto no litoral, áreas urbanas de João Pessoa e as terras indígenas Potiguara. Acompanhei ainda o Projeto Inventário de Cocos como Patrimônio Imaterial Brasileiro, o que me propiciou conhecer e conversar com muitos mestres populares e grupos culturais da Paraíba. E o que existia em comum entre essas pessoas que me levou até elas? Além de serem mestres e brincantes de cultura popular, eram conhecidos como bons cantadores ou contadores de causos. A pergunta que me movia era que histórias eles tinham para contar sobre o ambiente em que viviam e com que canções o representariam. Analisei as letras dos cocos e cirandas que foram cantados, em seus vários aspectos, considerando o contexto da brincadeira em que estão inseridos. Que representações de ambiente estão contidas nessas letras? Através das histórias que registrei pude perceber a amplitude da noção de ambiente para os meus colaboradores: podia estar se referindo tanto ao local em que vivem e realizam suas atividades cotidianas, povoado por animais e plantas ou ainda um ambiente encantado, povoado por seres fantásticos Comadre Fulozinha, Pai do Mangue, Mãe D'água. Assim, foi se desvelando diante de mim, através de causos e cantos, um ambiente vazado, impossível de ser apreendido.This research searches for other ways to see and narrate environment. Through interviews, oral history and audiovisual records, I tried to perceive how the environment is told and sung by the playing, singers and players (brincantes) from two popular manifestations of Paraíba - coco de roda and ciranda. To conduct fieldwork, I visited brincantes pertaining to Maroon communities in the coast and interior of the state, at the urban areas of João Pessoa and the Potiguara indigenous lands. I have also accompanied the Projeto Inventário de Cocos como Patrimônio Imaterial Brasileiro (Project for the Inventary of Cocos as Brazilian Immaterial Patrimony), and during this process I was able to talk to many popular teachers and cultural groups from Paraíba. What was the common thing between all these people that lead me to them? Besides being masters and players in popular culture, they were all known as good singers and storytellers. I was motivated by the questions of which stories they had to tell about the environment in which they lived and which songs represented this environment. I have analysed the lyrics of the cocos and cirandas, considering the playful context in which they are inserted. Which representations of the environment are present in these lyrics? Through the stories I have registered I was able to perceive that for my colaborators environment was a broad concept: it could refer to the place were they live and perform their daily activities, inhabited by plants and animals; or to an enchanted environment, populated by fantastic beings - Comadre Fulozinha, Pai do Mangue, Mãe D'água. Thus, through tales and songs I learned about a permeable environment, impossible to apprehend
Active breaks in primary school: Teacher awareness
No full textThe need for movement, which characterizes the current generations of children, has become urgent and worrying. Despite the continuous projects carried out in primary school, few seems to improve health and motivation to adopt active lifestyles. Among the many projects carried out in recent years, active breaks seem to be gaining ground for their easiness of realization and sustainability over time. The active breaks proved to be very effective towards well being and cognitive activation representing an additional dose of physical activity that can help children in meeting the recommended levels of daily physical activity. Moreover, the active breaks represent an innovative strategy to improve the classroom climate and facilitate the educational action of teachers. Teachers, involved in the I-MOVE and ABS studies, of an inter-university study group (University of Bologna and University of Roma Tre), responded with great enthusiasm to the practice of active breaks. Teachers highlighted that active break produced a positive effect toward school routine, learning environment and activation of cognitive functions in children. The present paper reports data related to the awareness of teachers, with regard to the application of active breaks in their school day, in terms of feasibility, management and organization in the face of effects considered absolutely positive for the daily school experience
H-1 Nuclear Magnetic Resonance Study of Olive Oils Commercially Available as Italian Products in the United States of America
No full textMultivariate analysis of H-1 NMR data has been used for the characterization of 12 blended olive oils commercially available in the U. S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U. S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy's leading olive oil producers, Picual (Spain), Kalamata (Greece) and Sfax (Tunisia). The olive oils commercially available as Italian products in the U. S. market clustered into 3 groups. Among them only the first (7 samples) and the second group (2 samples) showed PCA ranges similar to European references. Two oils of the third group (3 samples) were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils) tested were closer to Greek (in particular) and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic) and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions
A Novel 2-D Ray tracing Procedure for the Localization of EM Field Sources in Urban Environment
No full textSpecchi e unicorni: l'ambiguità della percezione in 'Rosencrantz and Guildenstern are Dead' di Tom Stoppard
No full texta cura di M. Billi, L. Curti, E. Di Piazza, D. Coron
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