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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Vetores de mudança na multifuncionalidade da paisagem costeira do Litoral Norte de São Paulo. /

Pierri-Daunt, Ana Beatriz January 2019 (has links)
Orientador: Thiago Sanna Freire Silva / Resumo: As paisagens são a expressão da interação dinâmica entre processos naturais e atividades humanas. A região do Litoral Norte do Estado de São Paulo apresenta uma grande diversidade de fitofisionomias do bioma Mata Atlântica, e um rico patrimônio material e imaterial, em função da histórica interação do homem com a natureza. São inúmeros os vetores que agem simultaneamente sobre essa paisagem, resultando em efeitos cumulativos que transformam sua multifuncionalidade e multidimensionalidade. Este estudo objetivou a compreensão dos vetores de mudanças na paisagem do Litoral Norte do Estado de São Paulo. A transformação histórica da paisagem na área de estudo foi investigada buscando compreender a modificações dos cenários paisagísticos na sua integridade desde o início da colonização europeia na região de estudo. Através desta revisão histórica, demonstramos que a política econômica impulsionou investimentos em instalações tecnológicas e de acesso a região, que influenciaram no aumento das taxas de crescimento populacional, resultando num rápido crescimento das áreas urbanas após meados do século XX. O segundo capítulo quantificou as mudanças físicas da paisagem, através de séries históricas de imagens da série de satélites Landsat, utilizando o algoritmo Random Forests para classificação supervisionada do uso e cobertura da terra. Pudemos então, demonstrar que a região apresenta tendência a uma dicotomia no uso da terra, entre o uso urbano e a conservação ambiental. Entre 1985 e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Landscapes are an expression of the dynamic interaction between natural environments and human activities. The Northern Coast of São Paulo State has a high diversity of Atlantic Forest vegetation types, and the Serra do Mar mountain range has a rich material and immaterial heritage due to ancient human-nature interactions. There are several different driving forces of change acting together over these landscapes, resulting in a cumulative effect over time. Our study sought to understand the causes and consequences of landscape change in the Northern Coast of São Paulo state, from 1985 to present. We described the land use history and landscape changes since the Europeans arrived in the region, during the XVI century. We identified that national economic policies and interests have led to investment in improved access and technological development, which in turn influenced migration to the region and resulted in fast urban expansion. In the second chapter, we have shown that land use change in the Northern Coast of São Paulo poses a dichotomy between two main land cover change trajectories over 30 years: forest persistence and fast urban growth. We found only 100 km² (8%) of forest disturbance within the State Parks, while dense urban settlements grew 167% outside the park, replacing mainly rural land uses. To identify and understand the driving forces of change in the region, we used Partial Least Squares - Path Modelling to model the relation between driving forces and lands... (Complete abstract click electronic access below) / Doutor
302

Sentidos e significados que professores atuando em escolas de periferia constituem para as dificuldades e desafios encontrados em sua profissão

Vieira, Elisandra Felix 16 October 2013 (has links)
Made available in DSpace on 2016-04-28T20:56:39Z (GMT). No. of bitstreams: 1 Elisandra Felix Vieira.pdf: 1657483 bytes, checksum: eb7fd84e293cdad229033a4de94385d3 (MD5) Previous issue date: 2013-10-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to grasp the senses and meanings that outlying public school teachers constitute for the difficulties and challenges they faced in their profession as well as how, according to them, these problems affect their ways of thinking, feeling and acting. Nowadays, teachers work is affected by proletarization, precarization and intensification of work, since they act in organizations with low budgets, doing a variety of functions that are not directly related to their profession, with rare opportunities of continuing professional development and, moreover, having to double or triple their daily schedule in order to make a paltry salary. Given this situation, we found it necessary to understand how these hardships affect teaching, more specifically that of Cristina, a teacher within the public school network of the municipality of São Paulo, in a Unified Educational Centre (CEU). From her narrative, as well as those of six other educators, it was possible to identify different indicators of subjective senses in these educational situations. Through articulation of the speeches, significations were identified that were gleaned as part of a dialectically determined society by means of social mediation, forming a picture that is, as the actual literature frequently points out, probably shared by the teaching professionals. The data obtained was analyzed according to the procedure suggested by Aguiar e Ozella (2006, 2013) and named Nuclei of Significations. In light of theoretical and analytical assumptions of sociocultural psychology and its main categories of analysis (historicity, mediation, thought, speech, senses and meanings), the results revealed that the distance between what is expected of the teachers and the little that they are offered in terms of resources and training has created feelings of abandonment and the desire to abscond from their professional responsibilities, as well as indifference and depersonalization, resulting from institutional problems which oppress them, producing an incapability to theorize beyond what they experienced and to understand the historical, political and economic determinations that impoverish the teaching career. Restricted by a precarious initial and continuous professional formation and by the limits of time and economic resources, the teachers need to be satisfied to teach at a level that is hardly related to pedagogical scientific knowledge / O presente estudo tem como objetivo compreender quais são os sentidos e significados que professores atuando em escolas de periferia constituem para as dificuldades e desafios encontrados em sua profissão e a maneira como, segundo eles, tais percalços afetam sua forma de pensar, sentir e agir. O trabalho docente na atualidade, em termos de processo, é afetado pela proletarização, precarização e intensificação do trabalho, uma vez que os docentes não estão isentos de trabalhar em estruturas organizacionais com baixos recursos, exercendo uma multiplicidade de funções alheias a sua formação, com escassas oportunidades de desenvolvimento profissional e, no mais das vezes, tendo que duplicar ou triplicar sua jornada de trabalho para fazer jus a um salário menos que razoável. Inseridos nesta lógica precária, achamos oportuno entender como esses percalços afetam o trabalho docente, especificamente o de uma professora da rede pública de São Paulo, que exerce sua profissão em um Centro Educacional Unificado (CEU). De seu relato, bem como do de outros seis educadores, foi possível identificar diferentes indicadores de sentidos subjetivos configurados nessas situações educacionais. A articulação das falas revela significações que são apreendidas como parte dialeticamente determinada da totalidade via mediações sociais, formando um retrato que é, possivelmente, compartilhado pelo coletivo profissional do magistério, como aponta, com frequência, a literatura atual. Os dados obtidos foram analisados de acordo com o procedimento de análise e interpretação proposto por Aguiar e Ozella (2006; 2013), núcleos de significações. À luz dos pressupostos teóricos e metodológicos da Psicologia Sócio-Histórica, e subsidiados pelas principais categorias de análise que sustentam o referencial adotado (historicidade, mediação, pensamento e linguagem, sentidos e significados), os resultados obtidos desta pesquisa revelaram que a distância entre o que se espera dos docentes e o pouco que lhes é oferecido em termos de recursos e formações têm produzido neles sentimentos de abandono e fuga frente às responsabilidades profissionais que lhes competem, além de indiferença e despersonalização, fruto das mazelas institucionais que os oprimem, produzem a incapacidade de sair do empírico e compreender as determinações históricas, políticas e econômicas que empobrecem a carreira do magistério. Restritos por uma formação inicial precária e pelas limitações de tempo e de recursos financeiros, os docentes precisam satisfazer-se em desempenhar uma docência pouco articulada ao conhecimento científico pedagógico
303

Preparation, characterization and carrier gas transport characteristics of inorganic and organic membranes for application in lactic acid esterification with ethanol

Okon, Edidiong January 2018 (has links)
Ethyl lactate (EL) plays a major role as green solvent and also a replacement for most petrochemical solvents. The esterification process of lactic acid and ethanol to produce EL is an equilibrium-limiting reaction and the selective removal of one of the reaction products can be improved using a membrane reactor and when coupled with a heterogeneous catalyst offers an opportunity for process intensification. This thesis investigates the batch process esterification reaction involving lactic acid (LA) and ethanol (EL) in the presence of a water selective membrane using different cation-exchange resin catalysts. The product was analysed using gas chromatograph coupled with mass spectrometry detector (GC-MS). The analytical methods used for the characterisation of the cation-exchange resins and membrane include Fourier transform infrared coupled with attenuated total reflectance (FTIR-ATR), scanning electron microscopy attached to energy dispersive analyser (SEM/EDAX), Liquid nitrogen physisorption and nuclear magnetic resonance (NMR) respectively. A novel method was developed for carrying out esterification reaction in a gaseous phase system using a flat sheet polymeric membrane. Prior to the esterification reaction, different carrier gases were tested with ceramic membrane to determine the suitable carrier gases for the analysis of esterification product. The four carrier gases used for the permeation test were argon (Ar), helium (He), carbon dioxide (CO2) and nitrogen (N2). A 15nm pore size commercially available tubular ceramic support, consisting of 77%Al2O3 and 23%TiO2 with the porosity of 45% was used for the carrier gas investigation. The support was modified with silica based on the sol-gel dip-coating techniques. The dip-coated membrane exhibited a higher molar flux with He (0.046mol m-2s-1) and Ar (0.037mol m-2s-1) with a much lower flux for N2 (0.037mol m-2s-1) and CO2 (0.035 mol m-2s-1) at 0.30 bar. Helium gas with the highest permeation rate were identified as the suitable carrier gas for the analysis of esterification product with GC-MS. The esterification reaction in the presence of four cation-exchange resins to produce ethyl lactate was carried out between 60-160 oC in a batch and membrane processes to determine the effectiveness resin catalysts for LA esterification. The effect of external mass transfer diffusion limitation between the liquid components and the resin catalysts was avoided by increasing the agitation time of the esterification reaction. The percentage conversion rate of the lactic acid feed from the batch process esterification was found to be in the range of 98.6 to 99.8%. The reaction kinetics of the esterification reaction was described based on two simplified mechanisms of Langmuir Hinshelwood model to describe the adsorption components on the surface of the catalysts. The lactic acid feed gave a conversion rate of up to 100 % confirming the effectiveness of the acetate membrane impregnated resin catalysts in the selective removal of water for the separation of ethyl lactate. The significance of producing ethyl lactate through batch process intensified by a water-selective membrane processes can be recommended for industrial LA production.
304

Global trade, food production and ecosystem support : Making the interactions visible

Deutsch, Lisa January 2004 (has links)
Modern food production is a complex, globalized system in which what we eat and how it is produced are increasingly disconnected. This thesis examines some of the ways in which global trade has changed the mix of inputs to food and feed, and how this affects food security and our perceptions of sustainability. One useful indicator of the ecological impact of trade in food and feed products is the Appropriated Ecosystem Areas (ArEAs), which estimates the terrestrial and aquatic areas needed to produce all the inputs to particular products. The method is introduced in Paper I and used to calculate and track changes in imported subsidies to Swedish agriculture over the period 1962-1994. In 1994, Swedish consumers needed agricultural areas outside their national borders to satisfy more than a third of their food consumption needs. The method is then applied to Swedish meat production in Paper II to show that the term “Made in Sweden” is often a misnomer. In 1999, almost 80% of manufactured feed for Swedish pigs, cattle and chickens was dependent on imported inputs, mainly from Europe, Southeast Asia and South America. Paper III examines ecosystem subsidies to intensive aquaculture in two nations: shrimp production in Thailand and salmon production in Norway. In both countries, aquaculture was shown to rely increasingly on imported subsidies. The rapid expansion of aquaculture turned these countries from fishmeal net exporters to fishmeal net importers, increasingly using inputs from the Southeastern Pacific Ocean. As the examined agricultural and aquacultural production systems became globalized, levels of dependence on other nations’ ecosystems, the number of external supply sources, and the distance to these sources steadily increased. Dependence on other nations is not problematic, as long as we are able to acknowledge these links and sustainably manage resources both at home and abroad. However, ecosystem subsidies are seldom recognized or made explicit in national policy or economic accounts. Economic systems are generally not designed to receive feedbacks when the status of remote ecosystems changes, much less to respond in an ecologically sensitive manner. Papers IV and V discuss the problem of “masking” of the true environmental costs of production for trade. One of our conclusions is that, while the ArEAs approach is a useful tool for illuminating environmentally-based subsidies in the policy arena, it does not reflect all of the costs. Current agricultural and aquacultural production methods have generated substantial increases in production levels, but if policy continues to support the focus on yield and production increases alone, taking the work of ecosystems for granted, vulnerability can result. Thus, a challenge is to develop a set of complementary tools that can be used in economic accounting at national and international scales that address ecosystem support and performance. We conclude that future resilience in food production systems will require more explicit links between consumers and the work of supporting ecosystems, locally and in other regions of the world, and that food security planning will require active management of the capacity of all involved ecosystems to sustain food production.
305

Design and Evaluation of Pressure-based Sensors for Mechanomyography: an Investigation of Chamber Geometry and Motion Artifact

Posatskiy, Alex 19 December 2011 (has links)
Mechanomyography (MMG) has been proposed as a control modality for alternative access technologies for individuals with disabilities. However, MMG recordings are highly susceptible to contamination from limb movements. Pressure-based transducers are touted to be the most robust to external movement although there is some debate about their optimal chamber geometry, in terms of low frequency gain and spectral flatness. To investigate the question of preferred geometry, transducers with varying chamber shapes were designed, manufactured and tested. The best performance was achieved with a transducer consisting of a low-frequency MEMS microphone, a 4 micron thick aluminized mylar membrane and a rigid conical chamber 7 mm in diameter and 5 mm in height. Furthermore, microphone-derived MMG spectra were found to be less influenced by motion artifact than corresponding accelerometer-derived spectra. However, artifact harmonics were present in both spectra, suggesting that bandpass filtering may not remove artifact influences permeating into MMG frequency bands.
306

Design and Evaluation of Pressure-based Sensors for Mechanomyography: an Investigation of Chamber Geometry and Motion Artifact

Posatskiy, Alex 19 December 2011 (has links)
Mechanomyography (MMG) has been proposed as a control modality for alternative access technologies for individuals with disabilities. However, MMG recordings are highly susceptible to contamination from limb movements. Pressure-based transducers are touted to be the most robust to external movement although there is some debate about their optimal chamber geometry, in terms of low frequency gain and spectral flatness. To investigate the question of preferred geometry, transducers with varying chamber shapes were designed, manufactured and tested. The best performance was achieved with a transducer consisting of a low-frequency MEMS microphone, a 4 micron thick aluminized mylar membrane and a rigid conical chamber 7 mm in diameter and 5 mm in height. Furthermore, microphone-derived MMG spectra were found to be less influenced by motion artifact than corresponding accelerometer-derived spectra. However, artifact harmonics were present in both spectra, suggesting that bandpass filtering may not remove artifact influences permeating into MMG frequency bands.
307

Agricultural intensification, biological pest control and spatio-temporal changes in food web structure / Intensivierung der Landwirtschaft, biologische Schädlingsbekämpfung und räumlich-zeitliche Veränderungen in der Struktur des Nahrungsnetzes

Gagic, Vesna 04 November 2011 (has links)
No description available.
308

Einfluss von ökologischem Landbau und Landschaftskomplexität auf die Wirbeltierdiversität und Ökosystemfunktionen / Effects of farming practice and landscape complexity on vertebrate diversity and ecological functioning in agroecosystems

Fischer, Christina 20 May 2010 (has links)
No description available.
309

Economic valuation of of land use change - A case study on rainforest conversion and agroforestry intensification in Central Sulawesi, Indonesia / Die ökomische Bewertung des Landnutzungswandels - Eine Fallstudie über die Umwandlung von Regenwald und die Intensivierung von Agroforstsystemen in Zentral-Sulawesi, Indonesien

Juhrbandt, Jana 08 July 2010 (has links)
No description available.
310

Adoption and impacts of system technologies in smallholder agriculture - the system of rice intensification in Timor Leste / Annahme und Wirkungen von Systemtechnologien in der kleinbäuerlichen Landwirtschaft - das System der Reis Intensivierung in Timor Leste

Noltze, Martin 24 May 2012 (has links)
No description available.

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