Dimensionamento de sistemas de aterramento em linhas de transmissão para escoamento eficiente de correntes de surtos atmosféricos

This work presents in a simulated environment, to analyze the length of cable needed counterweight connected to ground rod, able to avoid the phenomenon of flashover return, back flashover, the insulator chains of transmission lines consisting of concrete structures when they are subjected to lightning standardized regarding certain resistivity values of some kinds of soil and geometric arrangements of disposal of grounding systems structures

Desenvolvimento de uma unidade laboratorial para quantificação de BTX como poluentes atmosféricos, usando microextração em fase sólida

This dissertation aims the development of an experimental device to determine quantitatively the content of benzene, toluene and xylenes (BTX) in the atmosphere. BTX are extremely volatile solvents, and therefore play an important role in atmospheric chemistry, being precursors in the tropospheric ozone formation. In this work a BTX new standard gas was produced in nitrogen for stagnant systems. The aim of this dissertation is to develop a new method, simple and cheaper, to quantify and monitor BTX in air using solid phase microextraction/ gas chromatography/mass spectrometry (SPME/CG/MS). The features of the calibration method proposed are presented in this dissertation. SPME sampling was carried out under non-equilibrium conditions using a Carboxen/PDMS fiber exposed for 10 min standard gas mixtures. It is observed that the main parameters that affect the extraction process are sampling time and concentration. The results of the BTX multicomponent system studied have shown a linear and a nonlinear range. In the non-linear range, it is remarkable the effect of competition by selective adsorption with the following affinity order p-xylene > toluene > benzene. This behavior represents a limitation of the method, however being in accordance with the literature. Furthermore, this behavior does not prevent the application of the technique out of the non-linear region to quantify the BTX contents in the atmosphere.

Poluentes atmosféricos: monóxido e dióxido de carbono no nordeste do Brasil

The interference of man in the middle atmosphere can be evidenced by the presence of carbon monoxide, gas associated with burning fossil fuels and carbon dioxide content, essential for respiration of plants and thermal balance of the Earth. In this thesis we initially evaluated the intensity of the spatial distribution of carbon monoxide in the Northeast of Brazil, and subsequently the behavior of temporal variations of the pollutants carbon monoxide and carbon dioxide in the atmospheric boundary layer Maxaranguape / RN. Research has shown that, driven by speculation and promoting the occupation of land for agriculture, cattle ranching and tourism in the Northeast of Brazil, the changes established by the man in the middle geomorphological affect the lower troposphere on a large scale, with a predominance of concentrations in central Pernambuco, Paraiba's south-central and central-west of Alagoas. However, the study of Maxaranguape / RN results showed little variation in carbon monoxide and carbon dioxide, with the speed of the wind persisting with values greater than 7.8 m / s, showing dispersion and diffusion of pollutants which resulted in faster renewal of local atmospheric air

Desenvolvimento e calibração de fotômetro solar para medições da profundidade óptica por aerossóis e coluna de água precipitável

Instrumentation is a tool of fundamental importance for research in several areas of human knowledge. Research projects are often unfeasible when data cannot be obtained due to lack of instruments, especially due to impor ting difficulties and the high costs there associated. Thus, in order to collaborate with the enhancement of a national technology, a multiband hand - held sun p hotometer (FSM - 4) was developed to operate in the 500 nm, 670 nm, 870 nm and 940 nm bands. In the 500 nm, 670 nm and 870 nm bands aerosols are monitored for evaluation of the AOD (Aerosol Optical Depth), and the PWC (Precipitable Water Column) is evaluated in the 940 nm band. For the development of the mech anical and electronic parts for the FSM - 4, th e materials and componen ts should combine low cost and quality of the data collected. The calibration process utilized the Langley method (ML) and Modified Langley Method (MLM). These methods are usually applied at high altitudes in order to provide atmosp heric optical stability. This condition however can be found in low height sites as shown in the research by Liu et al. (2010). Thus, for calibration of the FSM - 4, we investigated the atmospher ic optical stability utilizing the ML and MLM at a site in the cit y of Caicó / RN, located in the s emiarid region in northeastern Brazil. This site lies in a region far aw ay from large urban centers and activities generating anthropogenic atmospheric pollution. Data for calibration of the prototype were collected usin g the FSM - 4 in two separate operations during the dry season, one in December 2012 and another in September 2013. The methodologies showed optical atmospheric instability in the studied region through the dispersion of the values obtained for the calibrati on constant. This dispersion is affected by the variability of AOD and PWC during the appl ication of the above mentioned methods . As an alternative to the descr ibed sun photometer calibration , a short study was performed using the sun photometer worldwide network AERONET/NASA (AERsol RObotic NETwork – US Space Agency), installed in Petrolina / PE in Brazil. Data were collected for three days utilizing the AERONET instruments and the FSM - 4, operating simultaneously on the same site. By way of the ML and MLM techniques, convergent test values were obtained for the calibration constants, despite the low amount of data collected. This calibration transfer methodology proved to be a viable alternative to the FSM - 4 calibration .

Genotoxicidade e composição do material particulado emitido pela queima de Biomassa: um estudo de caso em Tangará da Serra, Região da Amazônia Brasileira

Tangara da Serra is located on southwestern Mato Grosso and is found to be on the route of pollutants dispersion originated in the Legal Amazon s deforestation area. This region has also a wide area of sugarcane culture, setting this site quite exposed to atmospheric pollutants. The objective of this work was to evaluate the genotoxicity of three different concentrations of organic particulate matter which was collected from August through December / 2008 in Tangara da Serra, using micronucleus test in Tradescantia pallida (Trad-MCN). The levels of particulate matter less than 10μm (MP10) and black carbon (BC) collected on the Teflon and polycarbonate filters were determined as well. Also, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified on the samples from the burning period by gas chromatography detector with flame ionization detection (GC-FID). The results from the analyzing of alkanes indicate an antropic influence. Among the PAHs, the retene was the one found on the higher quantity and it is an indicator of biomass burning. The compounds indene(1,2,3-cd)pyrene and benzo(k)fluoranthene were identified on the samples and are considered to be potentially mutagenic and carcinogenic. By using Trad-MCN, it was observed a significant increase on the micronucleus frequency during the burning period, and this fact can be related to the mutagenic PAHs which were found on such extracts. When the period of less burnings is analyzed and compared to the negative control group, it was noted that there was no significant difference on the micronuclei rate. On the other hand, when the higher burning period is analyzed, statistically significant differences were evident. This study showed that the Trad-MCN was sensible and efficient on evaluating the genotoxicity potencial of organic matter from biomass burning, and also, emphasizes the importance of performing a chemical composition analysis in order to achieve a complete diagnosis on environmental risk control

Avaliação da biodessulfurização de 4-metildibenzotiofeno por Rhodococus rhodochrous (NRRL B-2149)

Crude oil has between 0.04 up to 5% of sulphur, the higher the oil the higher the sulphur levels. Sulphur usually gives problems such as corrosion in refinery, and once burnt produces SO2 that goes to atmosphere. This work aim to investigate the capacity of Rhodococcus rhodochrous (NRRL B-2149) to metabolize the model compound 4-methyldibenzotiophene (4-MDBT), to remove the sulphur and transform it in 2-hydroxybiphenyl (2-HBF) and sulphite using the 4S pathway. Kynetic runs were carried out in shaker at 120 rpm and 32°C. Samples were taken every 12h to assay substrate consume as well as cells production using HPLC. Results showed that R. rhodochrous NRRL B-2149 can use the 4S pathway in order to remove sulphur without change the carbon chain of the molecule as well as that cells and 4-MDBT affects the product formation. The production of 2-hydroxybiphenyl has interest for industry once it is a potent biocide. However, evaluation is necessary in order to obtain better results compatible with industry needs

Modelagem estocástica do índice de radiação ultravioleta na costa leste do nordeste do Brasil

The increase in ultraviolet radiation (UV) at surface, the high incidence of non-melanoma skin cancer (NMSC) in coast of Northeast of Brazil (NEB) and reduction of total ozone were the motivation for the present study. The overall objective was to identify and understand the variability of UV or Index Ultraviolet Radiation (UV Index) in the capitals of the east coast of the NEB and adjust stochastic models to time series of UV index aiming make predictions (interpolations) and forecasts / projections (extrapolations) followed by trend analysis. The methodology consisted of applying multivariate analysis (principal component analysis and cluster analysis), Predictive Mean Matching method for filling gaps in the data, autoregressive distributed lag (ADL) and Mann-Kendal. The modeling via the ADL consisted of parameter estimation, diagnostics, residuals analysis and evaluation of the quality of the predictions and forecasts via mean squared error and Pearson correlation coefficient. The research results indicated that the annual variability of UV in the capital of Rio Grande do Norte (Natal) has a feature in the months of September and October that consisting of a stabilization / reduction of UV index because of the greater annual concentration total ozone. The increased amount of aerosol during this period contributes in lesser intensity for this event. The increased amount of aerosol during this period contributes in lesser intensity for this event. The application of cluster analysis on the east coast of the NEB showed that this event also occurs in the capitals of Paraiba (João Pessoa) and Pernambuco (Recife). Extreme events of UV in NEB were analyzed from the city of Natal and were associated with absence of cloud cover and levels below the annual average of total ozone and did not occurring in the entire region because of the uneven spatial distribution of these variables. The ADL (4, 1) model, adjusted with data of the UV index and total ozone to period 2001-2012 made a the projection / extrapolation for the next 30 years (2013-2043) indicating in end of that period an increase to the UV index of one unit (approximately), case total ozone maintain the downward trend observed in study period

Análise cintilográfica da deposição pulmonar de radioaerossol após associação da nebulização através dos dispositivos mesh e jato com a ventilação não invasiva em indivíduos normais e com pneumopatias obstrutivas crônicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Classificação de imagens de ambientes coralinos: uma abordagem empregando uma combinação de classificadores e máquina de vetor de suporte

The use of the maps obtained from remote sensing orbital images submitted to digital processing became fundamental to optimize conservation and monitoring actions of the coral reefs. However, the accuracy reached in the mapping of submerged areas is limited by variation of the water column that degrades the signal received by the orbital sensor and introduces errors in the final result of the classification. The limited capacity of the traditional methods based on conventional statistical techniques to solve the problems related to the inter-classes took the search of alternative strategies in the area of the Computational Intelligence. In this work an ensemble classifiers was built based on the combination of Support Vector Machines and Minimum Distance Classifier with the objective of classifying remotely sensed images of coral reefs ecosystem. The system is composed by three stages, through which the progressive refinement of the classification process happens. The patterns that received an ambiguous classification in a certain stage of the process were revalued in the subsequent stage. The prediction non ambiguous for all the data happened through the reduction or elimination of the false positive. The images were classified into five bottom-types: deep water; under-water corals; inter-tidal corals; algal and sandy bottom. The highest overall accuracy (89%) was obtained from SVM with polynomial kernel. The accuracy of the classified image was compared through the use of error matrix to the results obtained by the application of other classification methods based on a single classifier (neural network and the k-means algorithm). In the final, the comparison of results achieved demonstrated the potential of the ensemble classifiers as a tool of classification of images from submerged areas subject to the noise caused by atmospheric effects and the water column

Avaliação da capacidade de adsorção do CO2 em zeólita 12X com gases sintéticos e originados da pirólise do lodo de esgoto

This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The activities were divided into four stages: study batch adsorption capacity of the adsorbent with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption studies were carried out under the following operating conditions: temperature 40 °C (for the pyrolysis of the sludge T = 600 °C), pressures of 0.55 to 5.05 bar (batch process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7 h and on the fixed bed was around 180 min. The results of this study showed that in batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed CO2 increases with the increases pressure, decreases with temperature increases and rises due the increase of activation temperature adsorbent. In the batch process were evaluated the breakthrough curves, which were compared with adsorption isotherms represented by the models of Langmuir, Freündlich and Toth. All models well adjusted to the experimental points, but the Langmuir model was chosen in view of its use in the dynamic model does not have implications for adsorption (indeterminacy and larger number of parameters such as occurred with others) in solving the equation. In the fixed bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the maximum adsorption percentage 46.7% at 40 °C temperature and 50 mL/min of flow rate. The model was satisfactorily fitted to the three breakthrough curves and the parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45 dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge showed a fast saturation with traces of aerosols presents in the gas phase into the fixed bed under the reaction process

Parâmetros físico-químicos de estrelas com planetas na missão CoRoT

In the present study we compute the atmospheric parameters (Teff , log g and vmic, [Fe/H]) and chemical abundance of 16 ions (Fe I, Fe II, O I, Si I, Na I, Mg I, Al I, Ca I, Ti I, Co I, Ni I, Rb I, Zr I, Ba II, La II and Cr I) for 16 solar-like stars with masses between 0:8 and 1:2 Mfi aproximatedly, including 10 planet-host stars detected by the CoRoT Space Mission. For this study, we use data from the ESO public archive: (i) high resolution spectra (R 47000) from the UVES spectrograph on the VLT/UT2-ESO (for 7 stars, covering the wavelength range 3450-4515 Å and 5500-9400 Å) and (ii) high resolution spectra from HARPS spectrograph on the La Silla-ESO 3.60 m telescope (for 9 stars, covering the wavelength range 4200-6865 Å). Our spectral analysis is based on MARCS models of atmosphere and Turbospectrum spectroscopic tools. On the base of the computed parameters, the referred abundances appears to follow the same behavior of the solar curve abundances. Further, one observes a signifficant correlation between the abundance ratio [m/Fe] and condensation temperature (Tc) of refractory elements (Tc > 900 K). The behavior of the projected rotational velocity (v sin i) versus the computed abundances [m/Fe] is also analyzed, presenting no clear trends. This study oers additional constraints to trace the evolutive history of solar-like stars with planets, including the search for chemical dierences between stars with and without transit planets and anomalies in the studied abundances

Três alternativas estocásticas para modelar morbimortalidade por doenças respiratórias e cardiovasculares via variáveis atmosféricas

Climate and air pollution, among others, are responsible factors for increase of health vulnerability of the populations that live in urban centers. Climate changes combined with high concentrations of atmospheric pollutants are usually associated with respiratory and cardiovascular diseases. In this sense, the main objective of this research is to model in different ways the climate and health relation, specifically for the children and elderly population which live in São Paulo. Therefore, data of meteorological variables, air pollutants, hospitalizations and deaths from respiratory and cardiovascular diseases a in 11-year period (2000-2010) were used. By using modeling via generalized estimating equations, the relative risk was obtained. By dynamic regression, it was possible to predict the number of deaths through the atmospheric variables and the betabinomial-poisson model was able to estimate the number of deaths and simulate scenarios. The results showed that the risk of hospitalizations due to asthma increases approximately twice for children exposed to high concentrations of particulate matter than children who are not exposed. The risk of death by acute myocardial infarction in elderly increase in 3%, 6%, 4% and 9% due to high concentrations CO, SO2, O3 and PM10, respectively. Regarding the dynamic regression modeling, the results showed that deaths by respiratory diseases can be predicted consistently. The beta-binomial-poisson model was able to reproduce an average number of deaths by heart insufficiency. In the region of Santo Amaro the observed number was 2.462 and the simulated was 2.508, in the Sé region 4.308 were observed and 4.426 simulated, which allowed for the generation of scenarios that may be used as a parameter for decision. Making with these results, it is possible to contribute for methodologies that can improve the understanding of the relation between climate and health and proved support to managers in environmental planning and public health policies.

Modelagem estatística e atribuições dos eventos de precipitação extrema na Amazônia brasileira

Intense precipitation events (IPE) have been causing great social and economic losses in the affected regions. In the Amazon, these events can have serious impacts, primarily for populations living on the margins of its countless rivers, because when water levels are elevated, floods and/or inundations are generally observed. Thus, the main objective of this research is to study IPE, through Extreme Value Theory (EVT), to estimate return periods of these events and identify regions of the Brazilian Amazon where IPE have the largest values. The study was performed using daily rainfall data of the hydrometeorological network managed by the National Water Agency (Agência Nacional de Água) and the Meteorological Data Bank for Education and Research (Banco de Dados Meteorológicos para Ensino e Pesquisa) of the National Institute of Meteorology (Instituto Nacional de Meteorologia), covering the period 1983-2012. First, homogeneous rainfall regions were determined through cluster analysis, using the hierarchical agglomerative Ward method. Then synthetic series to represent the homogeneous regions were created. Next EVT, was applied in these series, through Generalized Extreme Value (GEV) and the Generalized Pareto Distribution (GPD). The goodness of fit of these distributions were evaluated by the application of the Kolmogorov-Smirnov test, which compares the cumulated empirical distributions with the theoretical ones. Finally, the composition technique was used to characterize the prevailing atmospheric patterns for the occurrence of IPE. The results suggest that the Brazilian Amazon has six pluvial homogeneous regions. It is expected more severe IPE to occur in the south and in the Amazon coast. More intense rainfall events are expected during the rainy or transitions seasons of each sub-region, with total daily precipitation of 146.1, 143.1 and 109.4 mm (GEV) and 201.6, 209.5 and 152.4 mm (GPD), at least once year, in the south, in the coast and in the northwest of the Brazilian Amazon, respectively. For the south Amazonia, the composition analysis revealed that IPE are associated with the configuration and formation of the South Atlantic Convergence Zone. Along the coast, intense precipitation events are associated with mesoscale systems, such Squall Lines. In Northwest Amazonia IPE are apparently associated with the Intertropical Convergence Zone and/or local convection.

Genotoxicidade e composição do material particulado emitido pela queima de Biomassa: um estudo de caso em Tangará da Serra, Região da Amazônia Brasileira

Tangara da Serra is located on southwestern Mato Grosso and is found to be on the route of pollutants dispersion originated in the Legal Amazon s deforestation area. This region has also a wide area of sugarcane culture, setting this site quite exposed to atmospheric pollutants. The objective of this work was to evaluate the genotoxicity of three different concentrations of organic particulate matter which was collected from August through December / 2008 in Tangara da Serra, using micronucleus test in Tradescantia pallida (Trad-MCN). The levels of particulate matter less than 10μm (MP10) and black carbon (BC) collected on the Teflon and polycarbonate filters were determined as well. Also, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified on the samples from the burning period by gas chromatography detector with flame ionization detection (GC-FID). The results from the analyzing of alkanes indicate an antropic influence. Among the PAHs, the retene was the one found on the higher quantity and it is an indicator of biomass burning. The compounds indene(1,2,3-cd)pyrene and benzo(k)fluoranthene were identified on the samples and are considered to be potentially mutagenic and carcinogenic. By using Trad-MCN, it was observed a significant increase on the micronucleus frequency during the burning period, and this fact can be related to the mutagenic PAHs which were found on such extracts. When the period of less burnings is analyzed and compared to the negative control group, it was noted that there was no significant difference on the micronuclei rate. On the other hand, when the higher burning period is analyzed, statistically significant differences were evident. This study showed that the Trad-MCN was sensible and efficient on evaluating the genotoxicity potencial of organic matter from biomass burning, and also, emphasizes the importance of performing a chemical composition analysis in order to achieve a complete diagnosis on environmental risk control

Avaliação da biodessulfurização de 4-metildibenzotiofeno por Rhodococus rhodochrous (NRRL B-2149)

Crude oil has between 0.04 up to 5% of sulphur, the higher the oil the higher the sulphur levels. Sulphur usually gives problems such as corrosion in refinery, and once burnt produces SO2 that goes to atmosphere. This work aim to investigate the capacity of Rhodococcus rhodochrous (NRRL B-2149) to metabolize the model compound 4-methyldibenzotiophene (4-MDBT), to remove the sulphur and transform it in 2-hydroxybiphenyl (2-HBF) and sulphite using the 4S pathway. Kynetic runs were carried out in shaker at 120 rpm and 32°C. Samples were taken every 12h to assay substrate consume as well as cells production using HPLC. Results showed that R. rhodochrous NRRL B-2149 can use the 4S pathway in order to remove sulphur without change the carbon chain of the molecule as well as that cells and 4-MDBT affects the product formation. The production of 2-hydroxybiphenyl has interest for industry once it is a potent biocide. However, evaluation is necessary in order to obtain better results compatible with industry needs