Estudo de materiais mesoporosos funcionalizados com diferentes aminas para captura do dióxido de carbono através do processo de adsorção

Intensive use of machinery and engines burning fuel dumps into the atmosphere huge amounts of carbon dioxide (CO2), causing the intensification of the greenhouse effect. Climate changes that are occurring in the world are directly related to emissions of greenhouse gases, mainly CO2, gases, mainly due to the excessive use of fossil fuels. The search for new technologies to minimize the environmental impacts of this phenomenon has been investigated. Sequestration of CO2 is one of the alternatives that can help minimize greenhouse gas emissions. The CO2 can be captured by the post-combustion technology, by adsorption using adsorbents selective for this purpose. With this objective, were synthesized by hydrothermal method at 100 °C, the type mesoporous materials MCM - 41 and SBA-15. After the synthesis, the materials were submitted to a calcination step and subsequently functionalized with different amines (APTES, MEA, DEA and PEI) through reflux method. The samples functionalized with amines were tested for adsorption of CO2 in order to evaluate their adsorption capacities as well, were subjected to various analyzes of characterization in order to assess the efficiency of the method used for functionalization with amines. The physic-chemical techniques were used: X- ray diffraction (XRD), nitrogen adsorption and desorption (BET/BJH), scanning electron microscopy (SEM), transmission electron microscopy (TEM), CNH Analysis, Thermogravimetry (TG/DTG) and photoelectron spectroscopy X-ray (XPS). The CO2 adsorption experiments were carried out under the following conditions: 100 mg of adsorbent, at 25 °C under a flow of 100 ml/min of CO2, atmospheric pressure and the adsorption variation in time 10-210 min. The X-ray diffraction with the transmission electron micrographs for the samples synthesized and functionalized, MCM-41 and SBA-15 showed characteristic peaks of hexagonal mesoporous structure formation, showing the structure thereof was obtained. The method used was efficient reflux according to XPS and elemental analysis, which showed the presence of amines in the starting materials. The functionalized SBA -15 samples were those that had potential as best adsorbent for CO2 capture when compared with samples of MCM-41, obtaining the maximum adsorption capacity for SBA-15-P sample

Estratigrafia de sequências do intervalo aptiano ao albino na Bacia do Araripe, NE do Brasil

This study has as a main objective to make a detailed stratigraphic analysis of the Aptian-Albian interval in the east part of Araripe Basin, NE of Brazil which correspond, litostratigraphically, to Rio Da Batateira, Crato, Ipubi and Romualdo formations. The stratigraphic analysis was based on three different stages, the 1D, 2D and 3D analysis; these ones were adapted to the sequence stratigraphy concepts in order to create a chronostratigraphic framework for the study area within the basin. The database used in the present study contains field and well information, wells that belong to Santana Project, carried out by the Ministério de Minas e Energia- DNPM- CPRM from 1977 to 1978. The analysis 1D, which was done separately for each well and outcrop allowed the recognition of 13 sedimentary facies, mainly divided based on predominant litologies and sedimentary structures. Such facies are lithologically represented by pebble, sandstones, claystones, margas and evaporates; these facies are associated in order to characterize different depositional systems, that integrate from the continental environment (fluvial system and lacustre), paralic system (delta system and lagunar) to the marine environment (shelfenvironment). The first one, the fluvial system was divided into two subtypes: meandering fluvial system, characterized by fill channel and floodplain deposits; the facies of this system are associated vertically according to the textural thinning upward cycles (dirting-up trend pattern in well logs). Lacustrine environment is mainly related with the lithotypes of the Crato Formation, it shows a good distribution within the basin, been composed by green claystone deposits and calcareous laminated. Deltaic System represented by prodelta and delta front deposits which coarsening upward tendency. Lagunar system is characterised by the presence of anhydrite and gypsum deposits besides the black claystone deposits with vegetal fragments which do not contain a fauna typically marine. The marine platform system is composed by successions of black and gray claystone with fossiliferous fauna of Dinoflagellates (Spiniferites Mantell, Subtilisphaera Jain e Subtilisphaera Millipied genre) typical of this kind of depositional system. The sedimentary facies described are vertically arranged in cycles with progradational patterns which form textural coersening upward cycles and retrogradational, represented by textural thinning dowward cycles. Based in these cycles, in their stack pattern and the vertical change between these patterns, the systems tracks and the depositional sequences were recognized. The Low System Track (LST) and High System Track (HST) are composed by cycles with progradational stack pattern, whereas the Trangessive System Track (TST) is composed by retrogradational stack pattern cycles. The 2D stratigraphic analysis was done through the carrying out of two stratigraphic sections. For the selection of the datum the deepest maximum flooding surface was chosen, inside the Sequence 1, the execution of these sections allowed to understand the behaviour of six depositional systems along the study area, which were interpreted as cycles of second order or supercycles (cycles between 3 and 10 Ma), according to the Vail, et al (1977) classification. The Sequence 1, the oldest of the six identified is composed by the low, transgressive and high systems tracks. The first two system tracks are formed exclusively by fluvial deposits of the Rio da Batateira Formation whereas the third one includes deltaic and lacustrine deposits of the Crato Formation. The sequences 2 and 3 are formed by the transgressive systems tracks (lake spreading phase) and the highstand system track (lake backward phase). The TST of these sequences are formed by lacustrine deposits whereas HST contains deltaic deposits, indicating high rates of sedimentary supply at the time of it s deposition. The sequence 4 is composed by LST, TST and HST, The TST4 shows a significant fall of the lake base level, this track was developed in conditions of low relation between the creation rate of space of accommodation and the sedimentary influx. The TST4 marks the third phase of expansion of the lacustrine system in the section after the basin´s rift, the lacustrine system established in the previous track starts a backward phase in conditions that the sedimentary supply rate exceeds the creation rate of space accommodation. The sequence 5 was developed in two different phases, the first one is related with the latest expansion stage of the lake, (TST5), the basal track of this sequence. In this phase the base level of the lake rose considerably. The second phase (related to the TST5) indicates the end of the lacustrine domain in the Araripe Basin and the change to lagunar system ant tidal flat, with great portions in the supratidal. These systems were formed by restricted lagoons, with shallow level of water and with intermittent connections with the sea. This, was the phase when the Araripe Basin recorded the most several arid conditions of the whole interval studied, Aptian Albian, conditions that allow the formation of evaporitic deposits. The sequence 6 began its deposition after a significant fall of the sea (LST6). The sequence 6 is without any doubtlessly, the sequence that has deposits that prove the effective entrance of the sea into the Araripe Basin. The TST6, end of this sequence, represents the moment which the sea reaches its maximum level during the Aptian Albian time. The stratigraphic analysis of the Aptian Albian interval made possible the understanding that the main control in the development of the depositional sequences recognized in the Araripe Basin were the variations of the local base level, which are controlled itself by the climate changes

As relações entre tectonismo e seqüências deposiconais no rifte potiguar - porção SW do Graben de Umbuzeiro, bacia potiguar emersa

Through an integrated approach, using litho, chrono and biostratigraphic data, the relative importance of climate variations and tectonics were recognized in rift sediments of the onshore Potiguar Basin, Northeast Brazil. Concepts of sequence stratigraphy were applied as a template to integrate sedimentological and geochemical data (oxygen isotopes), as well as quantitative palynologic methods to address and recognize the main depositional patterns produced in a rift basin. The main objective was to address the relative importance of climate changes and tectonics to the resultant stratigraphic architecture. The results of computer simulations of sedimentary basin fills of rift basins were quite useful to test working hypothesis and mimic the process of filling a half graben during a rift event. The studied section includes a neovalanginian-eobarremian (Lower Cretaceous) rift interval from the Pendência Formation, located in the southwestern portion of Umbuzeiro Graben, in the offshore Potiguar Basin. The depositional setting is interpreted as progradational deltaic system entering a lake from its flexural margin. Sismoestratigraphyc and well logs analyses allowed to interpret two regressive intervals (Green and Yellow Sequences), separated by a broad transgressive interval (Orange Sequence), known as the Livramento Shale. The depositional history encompass three stages: two tectonically active phases, during the deposition of the Green and Yellow Sequences, and a tectonically quiescent phase, during the deposition of the Orange Sequence. Paleoclimatic interpretation, based on quantitative palynology and geochemical data (��18O), suggests a tendency to arid conditions during the tectonically active phases and wet conditions during the tectonically quiescent phase. Stratigraphic modeling and backstripping techniques, supported by paleoclimatic/paleoecologic interpretations provide a powerful methodology to evaluate the tectonic and climatic controls on tectonic lakes

Structure and function of the foregut and salivary glands of the synanthropic diplopod Urostreptus atrobrunneus (Spirostreptidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Variações interanuais na fenologia de uma comunidade arbórea de floresta semidecídua no sudeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Socio-climatic hotspots in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of liming on residual soil respiration and chemical properties in a tropical no-tillage system

Devido às mudanças climáticas do planeta, principalmente ao aquecimento global, as formas de utilização dos solos na agricultura têm atraído grande atenção de pesquisadores. Mudanças de manejo podem influenciar a respiração do solo e, por conseguinte, alterar drasticamente o sequestro de C. Os objetivos deste trabalho foram avaliar, em semeadura direta, a influência da calagem nas emissões de CO2 do solo e correlacioná-las aos atributos químicos deste após dois anos da calagem. Utilizou-se o delineamento em blocos casualizados, com seis repetições. Os tratamentos constituíram de quatro doses de calcário e uma testemunha. Decorridos dois anos da calagem, avaliou-se a emissão residual de CO2 do solo, coletaram-se amostras nas camadas de 0-5, 5-10, 10-20 e 20-30 cm de profundidade e determinaram-se os teores de P, Ca2+ e Mg2+ e valores de pH e de saturação por bases. A emissão residual de CO2 do solo, quando a dose recomendada foi aplicada, foi 24,1 % superior, quando comparada à do solo sem aplicação de calcário, e 47,4 % maior, quando se aplicou o dobro da dose recomendada. A calagem melhorou as condições químicas do solo, e a emissão de CO2 aumentou linearmente com o aumento das doses. A emissão de CO2 do solo apresentou correlações positivas com os teores de P, Ca2+ e Mg2+ e com os valores de pH e de saturação por bases e negativas com os teores de H + Al e Al3+. Maiores coeficientes de correlação entre as taxas de emissão de CO2 do solo e os atributos químicos deste ocorreram na camada de 10-20 cm.

Variabilidade temporal e meridional de estimativas de Satélite da concentração de clorofila superficial na plataforma continental brasileira

Forecast of biological consequences of climate changes depend on both long-term observations and the establishment of carbon budgets within pelagic ecosystems, including the assessment of biomasses and activities of all players in the global carbon cycle. Approximately 25% of oceanic primary happen over continental shelves, so these are important sites for studies of global carbon dynamics. The Brazilian Continental Shelf (BCS) has sparse and non-systematic in situ information on phytoplankton biomass, making products derived from ocean color remote sensing extremely valuable. This work analyzes chlorophyll concentration (Chl) estimated from four ocean color sensors (CZCS, OCTS, SeaWiFS and MODIS) over the BCS, to compare Chl and annual cycles meridionally. Also, useful complementary ocean color variables are presented. Chl gradients increased from the central region towards north and south, limited by estuarine plumes of Amazon and La Plata rivers, and clear annual Chl cycles appear in most areas. In southern and central areas, annual cycles show strong seasonal variability while interannual and long-term variability are equally important in the remaining areas. This is the first comparative evaluation of the Chl over the BCS and will aid the understanding of its long-term variability; essential initial step for discussions of climate changes.

Os Paradigmas da imprensa na cobertura das políticas ambientais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ferramentas matemáticas para modelagem da temperatura com aplicação em graus-dias para otimização da produção agrícola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Instrumentos jurídicos do MDL - mecanismo de desenvolvimento limpo na implementação de reserva legal para fins energéticos no Brasil

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Uso de filtro de mangas para tratamento de gases resultantes da combustão de bagaço de cana

Pós-graduação em Engenharia Mecânica - FEB

Alterações climáticas e a percepção dos munícipes de Rio Claro - SP

Pós-graduação em Geografia - IGCE

Análise do campo térmico de cidades de médio porte: estudo de caso no pólo textil de Americana - SP

Pós-graduação em Geografia - IGCE