940 resultados para 2G three-axis super-conducting rock magnetometer


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A presente pesquisa, de natureza qualitativa, está direcionada à análise das políticas educacionais ligadas à democratização da gestão escolar e demais processos escolares ligados à avaliação. Nesse contexto, é evidenciado o Conselho de Classe e Série, pois esse vem se concretizando como um dos espaços que favorecem a participação de pais e alunos, tornando-se fator determinante para a qualidade da democratização da gestão escolar e do ensino-aprendizagem. A pesquisa desenvolveu-se em três momentos: (1) análise da documentação escolar; (2) estudo de caso em duas instituições escolares da Rede Pública de São Paulo e (3) entrevistas com pais, alunos, professores e gestores que serviram de parâmetros para saber como estão realizadas as reuniões de Conselho de Classe e Série. Os objetivos da pesquisa foram voltados para verificar como vem sendo estruturada a participação da comunidade na construção da gestão democrática da escola, principalmente nas práticas do Conselho de Classe e Série.(AU)

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SINNMR (Sonically Induced Narrowing of the Nuclear Magnetic Resonance spectra of solids), is a novel technique that is being developed to enable the routine study of solids by nuclear magnetic resonance spectroscopy. SINNMR aims to narrow the broad resonances that are characteristic of solid state NMR by inducing rapid incoherent motion of solid particles suspended in a support medium, using high frequency ultrasound in the range 2-10 MHz. The width of the normal broad resonances from solids are due to incomplete averaging of several components of the total spin Hamiltonian caused by restrictions placed on molecular motion within a solid. At present Magic Angle Spinning (MAS) NMR is the classical solid state technique used to reduce line broadening, but: this has associated problems, not least of which is the appearance of many spinning side bands which confuse the spectra. It is hoped that SlNNMR will offer a simple alternative, particularly as it does not reveal spinning sidebands The fundamental question concerning whether the use of ultrasound within a cryo-magnet will cause quenching has been investigated with success, as even under the most extreme conditions of power, frequency and irradiator time, the magnet does not quench. The objective of this work is to design and construct a SINNMR probe for use in a super conducting cryo-magnet NMR spectrometer. A cell for such a probe has been constructed and incorporated into an adapted high resolution broadband probe. It has been proved that the cell is capable of causing cavitation, up to 10 MHz, by running a series of ultrasonic reactions within it and observing the reaction products. It was found that the ultrasound was causing the sample to be heated to unacceptable temperatures and this necessitated the incorporation of temperature stabilisation devices. Work has been performed on the investigation of the narrowing of the solid state 23Na spectrum of tri-sodium phosphate using high frequency ultrasound. Work has also been completed on the signal enhancement and T1 reduction of a liquid mixture and a pure compound using ultrasound. Some preliminary "bench" experiments have been completed on a novel ultrasonic device designed to help minimise sample heating. The concept involves passing the ultrasound through a temperature stabilised, liquid filled funnel that has a drum skin on the end that will enable the passage of ultrasound into the sample. Bench experiments have proved that acoustic attenuation is low and that cavitation in the liquid beyond the device is still possible.

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Three types of crushed rock aggregate were appraised, these being Carboniferous Sandstone, Magnesian Limestone and Jurassic Limestone. A comprehensive aggregate testing programme assessed the properties of these materials. Two series of specimen slabs were cast and power finished using recognised site procedures to assess firstly the influence of these aggregates as the coarse fraction, and secondly as the fine fraction. Each specimen slab was tested at 28 days under three regimes to simulate 2-body abrasion, 3-body abrasion and the effect of water on the abrasion of concrete. The abrasion resistance was measured using a recognised accelerated abrasion testing apparatus employing rotating steel wheels. Relationships between the aggregate and concrete properties and the abrasion resistance have been developed with the following properties being particularly important - Los Angeles Abrasion and grading of the coarse aggregate, hardness of the fine aggregate and water-cement ratio of the concrete. The sole use of cube strength as a measure of abrasion resistance has been shown to be unreliable by this work. A graphical method for predicting the potential abrasion resistance of concrete using various aggregate and concrete properties has been proposed. The effect of varying the proportion of low-grade aggregate in the mix has also been investigated. Possible mechanisms involved during abrasion have been discussed, including localised crushing and failure of the aggregate/paste bond. Aggregates from each of the groups were found to satisfy current specifications for direct finished concrete floors. This work strengthens the case for the increased use of low-grade aggregates in the future.

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The pine rocklands of South Florida, characterized by a rich herbaceous flora with many narrowly endemic taxa beneath an overstory of south Florida slash pine (Pinus elliottii var. densa), are found in three areas: the Miami Rock Ridge of southeastern peninsular Florida, the Lower Florida Keys, and slightly elevated portions of the southern Big Cypress National Preserve. Fire is an important element in these ecosystems, since in its absence the pine canopy is likely to be replaced by dense hardwoods, resulting in loss of the characteristic pineland herb flora. Prescribed fire has been used in Florida Keys pine forests since the creation of the National Key Deer Refuge (NKDR), with the primary aim of reducing fuels. Because fire can also be an effective tool in shaping ecological communities, we conducted a 4-year research study which explored a range of fire management options in NKDR. The intent of the study was to provide the Fish and Wildlife Service and other land managers with information regarding when and where to burn in order to perpetuate these unique forests.

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The goal of this research is to check if the strategic planning developed between 2001 and 2009 into the State University of Para (Universidade Federal do Pará - UFPA) was consolidated into its Academic Centers as a management practice. To this end, we identified the planning formalization degree of the Academic Centers, the conceived tools for the planning, the conception and the methodological process used in the tools elaboration, as also its implementation. The research used a qualitative approach: it is descriptive and it uses the case study technique. The data were gathered from primary and secondary sources, through bibliography, documents, and field researches through semi-structure interviews. The analysis and data interpretation were done by each investigated Academic Center from the analytics categories guided by the specifics goals. We used theoretic fundamental based principles and the university as a study empiric reference based on its structure analysis, organizational processes and institutional strategic plan. We inspected how the strategic planning process was developed throughout the fixed period and how the investigated Academic Centers are from the collected documents and interviews. The theoretical foundation was built from three axis: the Brazilian undergraduate and posgraduate education system; the university itself including its singularity and complexity as an organization; and the planning as a strategic management process. The main results show us that the UFPA has updated regulatory milestones, presenting organizational structure, laws, instructions, manuals and deployed management model that give the strategic planning development conditions beyond its administration, i. e., into its Academic Centers. The centers also present those established milestones and develop the basic planning processes of the institution. Those processes are conceived based on the institutional strategic planning and the managers mainly use the procedural orientation defined by the university management, from where the conceptual foundation is originated and propagated. According to the literature and to the research done in this work, we can conclude that the Academic Centers from the UFPA developed the strategic planning practice. This planning is organized and founded and guided the plans and decisions which avoided the disordered management and, according to the managers, allowed the advances and performance improvement. We can conclude that the UFPA built an important foundation with respect to the management professionalization. On the other hand, we can not conclude that the management practice is consolidated since there are weaknesses into the structuring of the technical teams and there is not any management tool for the implementation of the elaborated plans

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The goal of this research is to check if the strategic planning developed between 2001 and 2009 into the State University of Para (Universidade Federal do Pará - UFPA) was consolidated into its Academic Centers as a management practice. To this end, we identified the planning formalization degree of the Academic Centers, the conceived tools for the planning, the conception and the methodological process used in the tools elaboration, as also its implementation. The research used a qualitative approach: it is descriptive and it uses the case study technique. The data were gathered from primary and secondary sources, through bibliography, documents, and field researches through semi-structure interviews. The analysis and data interpretation were done by each investigated Academic Center from the analytics categories guided by the specifics goals. We used theoretic fundamental based principles and the university as a study empiric reference based on its structure analysis, organizational processes and institutional strategic plan. We inspected how the strategic planning process was developed throughout the fixed period and how the investigated Academic Centers are from the collected documents and interviews. The theoretical foundation was built from three axis: the Brazilian undergraduate and posgraduate education system; the university itself including its singularity and complexity as an organization; and the planning as a strategic management process. The main results show us that the UFPA has updated regulatory milestones, presenting organizational structure, laws, instructions, manuals and deployed management model that give the strategic planning development conditions beyond its administration, i. e., into its Academic Centers. The centers also present those established milestones and develop the basic planning processes of the institution. Those processes are conceived based on the institutional strategic planning and the managers mainly use the procedural orientation defined by the university management, from where the conceptual foundation is originated and propagated. According to the literature and to the research done in this work, we can conclude that the Academic Centers from the UFPA developed the strategic planning practice. This planning is organized and founded and guided the plans and decisions which avoided the disordered management and, according to the managers, allowed the advances and performance improvement. We can conclude that the UFPA built an important foundation with respect to the management professionalization. On the other hand, we can not conclude that the management practice is consolidated since there are weaknesses into the structuring of the technical teams and there is not any management tool for the implementation of the elaborated plans

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Technology has an important role in children's lives and education. Based on several projects developed with ICT, both in Early Childhood Education (3-6 years old) and Primary Education (6-10 years old), since 1997, the authors argue that research and educational practices need to "go outside", addressing ways to connect technology with outdoor education. The experience with the projects and initiatives developed supported a conceptual framework, developed and discussed with several partners throughout the years and theoretically informed. Three main principles or axis have emerged: strengthening Children's Participation, promoting Critical Citizenship and establishing strong Connections to Pedagogy and Curriculum. In this paper, those axis will be presented and discussed in relation to the challenge posed by Outdoor Education to the way ICT in Early Childhood and Primary Education is understood, promoted and researched. The paper is exploratory, attempting to connect theoretical and conceptual contributions from Early Childhood Pedagogy with contributions from ICT in Education. The research-based knowledge available is still scarce, mostly based on studies developed with other purposes. The paper, therefore, focus the connections and interpellations between concepts established through the theoretical framework and draws on the almost 20 years of experience with large and small scale action-research projects of ICT in schools. The more recent one is already testing the conceptual framework by supporting children in non-formal contexts to explore vineyards and the cycle of wine production with several ICT tools. Approaching Outdoor Education as an arena where pedagogical and cultural dimensions influence decisions and practices, the paper tries to argue that the three axis are relevant in supporting a stronger connection between technology and the outdoor.

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We present a suite of new high-resolution records (0-135 ka) representing pulses of aeolian, fluvial, and biogenic sedimentation along the Senegalese continental margin. A multiproxy approach based on rock magnetic, element, and color data was applied on three cores enclosing the present-day northern limit of the ITCZ. A strong episodic aeolian contribution driven by stronger winds and dry conditions and characterized by high hematite and goethite input was revealed north of 13°N. These millennial-scale dust fluxes are synchronous with North Atlantic Heinrich stadials. Fluvial clay input driven by the West African monsoon predominates at 12°N and varies at Dansgaard-Oeschger time scales while marine productivity is strongly enhanced during the African humid periods and marine isotope stage 5. From latitudinal signal variations, we deduce that the last glacial ITCZ summer position was located between core positions at 12°26' and 13°40'N. Furthermore, this work also shows that submillennial periods of aridity over northwest Africa occurred more frequently and farther south than previously thought.

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The magnetic microparticle and nanoparticle inventories of marine sediments from equatorial Atlantic sites were investigated by scanning and transmission electron microscopy to classify all present detrital and authigenic magnetic mineral species and to investigate their regional distribution, origin, transport, and preservation. This information is used to establish source-to-sink relations and to constrain environmental magnetic proxy interpretations for this area. Magnetic extracts were prepared from sediments of three supralysoclinal open ocean gravity cores located at the Ceará Rise (GeoB 1523-1; 3°49.9'N/41°37.3'W), the Mid-Atlantic Ridge (GeoB 4313-2; 4°02.8'N/33°26.3'W), and the Sierra Leone Rise (GeoB 2910-1; 4°50.7'N/21°03.2'W). Sediments from two depths corresponding to marine isotope stages 4 and 5.5 were processed. This selection represents glacial and interglacial conditions of sedimentation for the western, central, and eastern equatorial Atlantic and avoids interferences from subsurface and anoxic processes. Crystallographic, elemental, morphological, and granulometric data of more than 2000 magnetic particles were collected by scanning and transmission electron microscopy. On basis of these properties, nine particle classes could be defined: detrital magnetite, titanomagnetite (fragmental and euhedral), titanomagnetite-hemoilmentite intergrowths, silicates with magnetic inclusions, microcrystalline hematite, magnetite spherules, bacterial magnetite, goethite needles, and nanoparticle clusters. Each class can be associated with fluvial, eolian, subaeric, and submarine volcanic, biogenic, or chemogenic sources. Large-scale sedimentation patterns are delineated as well: detrital magnetite is typical of Amazon discharge, fragmental titanomagnetite is a submarine weathering product of mid-ocean ridge basalts, and titanomagnetite-hemoilmenite intergrowths are common magnetic particles in West African dust. This clear regionalization underlines that magnetic petrology is an excellent indicator of source-to-sink relations. Hematite encrustations, magnetic spherules, and nanoparticle clusters were found at all investigated sites, while bacterial magnetite and authigenic hematite were only detected at the more oxic western site. At the eastern site, surface pits and crevices were seen on the crystal faces indicating subtle early diagenetic reductive dissolution. It was observed that paleoclimatic signatures of magnetogranulometric parameters such as the ratio of anhysteretic and isothermal remanent magnetizations can be formed either by mixing of multiple sources with separate, relatively narrow grain size ranges (western site) or by variable sorting of a single source with a broad grain size distribution (eastern site). Hematite, goethite, and possibly ferrihydrite nanoparticles occur in all sediment cores studied and have either high-coercive or superparamagnetic properties depending on their partly ultrafine grain sizes. These two magnetic fractions are generally discussed as separate fractions, but we suggest that they could actually be genetically linked.