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Material particulado atmosférico na cidade de São Carlos- SP: quantificação e identificação de fontes
(Universidade Federal de São Carlos, 2005-05-05) Bruno, Ricardo Luiz; Coury, José Renato; https://lattes.cnpq.br/3711547435042712
In the present work, breathable particulate matter (PM10) concentration was measured in their fine (PM2.5-10) and ultra-fine (MP2.5) fractions, in the municipal district of São Carlos. The samplings were carried out from 2001 to 2004 for PM10 (complemented with data from 1997 to 2001 taken from the research group databank) and for the period of 1 year (2001-2002) for PM2.5. PM10 was sampled with a high volumes sampler, while PM2.5 and PM2.5-10 were sampled with a dichotomous sampler. In order rationalize the seasonal variation MP, the year was separated in two different periods, the so-called dry period characterized by colder months and smaller incidence of rains and the rainy period, characterized by hotter months and by larger incidence of rains. After the collection, XRF analysis were carried out to quantify the chemical elements with mass molar superior to 12 a.m.u.. Also, DIC/DOC (dissolved organic and inorganic carbon) analysis were performed. The results showed 14 chemical elements, on average, both in fne and ultrafine fractions. The chemical elements that appear in larger concentrations in the PM are organic carbon, inorganic carbon, Al, Si, Ca, Ti, K, S and Fe. Two receptor models, the principal factors analysis (PFA) and chemical mass balance (CMB) were used to quantify the probable pollution sources for responsible for the sampled PM in the receptor site. PFA suggests that 3 main sources are responsible for the PM in the ultrafine fraction, both in the dry as well as in the rainy season. As for the fine fraction, the PFA suggests that 4 main sources are responsible for the pollution in the receptor site. The CMB analysis indicates that, for the ultrafine fraction the main source is the gas/particle conversion from sulfur, both in the dry and rainy periods. For the dry period, the biomass burning becomes significant as a pollution source. In the fine fraction of MP, the main sources identified were soil resuspension and vehicular emission.
Estudos moleculares da Selenocisteína Sintase (SELA) de Escherichia coli
(Universidade Federal de São Carlos, 2005-05-05) Cassago, Alexandre; Thiemann, Otávio Henrique; https://lattes.cnpq.br/4933022274560322
The study of translation processes attracts the interest of a wide range of research groups due to its main role in general cellular metabolism. In particular, the investigation of new amino acid residues, such as selenocysteine and pyrrolysin, which result in an expansion of the genetic code from the traditional 20 residues to a total of 22 residues up to the current time. The amino acid, selenocysteine represents the main biological form of the selenium element and its synthesis and co-translational incorporation into selenoproteins are due to an in-frame UGA stop codon using complex molecular machinery. On Escherichia coli, the main proteins involved in this pathway are: Selenocysteine Synthase (SELA), Selenocysteine Elongation Factor (SELB or EFSec), Selenophosphate Synthetase (SELD) and a tRNAsec uca specific for this pathway named Selenocysteine Insertion tRNA (SELC). The SELA protein, the subject of this study, was firstly purified by Forchhammer in 1991 and the sole structural analysis realized to this day was developed by Engelhardt in 1992, using the Scanning Transmission Electron Microscope (STEM) technique. With a monomer of approximately 50kDa, SELA assumes an homodecamerical spatial configuration, each dimmer capable of binding to a tRNAsec uca with the serine amino acid which will be converted in selenocysteine, in a reaction dependant of the enzymatic cofactor piridoxal 5 fosfato. On this work it was possible to develop a new purification protocol for the SELA protein, considerably reducing the steps and consequently the time involved for obtaining purified protein. The process also yielded better protein production when compared to literature, from 1mg/ml starting with 10 liters to approximately 4.5mg/ml starting with 3 liters of bacterial medium. As for the structural experiments, it was possible to predict by Dynamic Light Scattering (DLS) the molecular mass as about 442kDa, Circular Dichroism (CD) predicted the secondary structure as mainly composed by α-helices and Small Angle X-ray Scattering (SAXS) showed the global structure of SELA with a maximum diameter of 185Å, a molecular mass of about 527kDa and a radius of gyration of 67.3 Å
Modelagem da demanda de água de abastecimento para a cidade de Pirassununga - SP
(Universidade Federal de São Carlos, 2005-05-05) Silva, João Batista da; Barbassa, Ademir Paceli; https://lattes.cnpq.br/2979012440240781
Because it is a natural resource that is vital to animal and vegetable life, and considered a temporary resource, water must be used with responsibility, aiming at its protection and preservation so there is no lack of it in the near future. There are several factors that contribute to the scarcity of water, ranging from the lack of a conservationist policy to the lack of consumer awareness. Predicting the average water consumption based on historic data is an important tool to be used in the planning, in the estimate of the consumption and in the direction of the sanitation management. The objective of this work is to analyze and model the data on the urban water consumption in the city of Pirassununga, State of São Paulo, from 1993 to 2002. The explanatory variables used were: the number of inhabitants per connection, the marginal water price, the ‘per capita’ income per household (replaced by the next added value), the temperature, the precipitation and the relative humidity of the air. The method of consumption per connection, the method by unitary coefficient and the linear model of multiples coefficients were applied after the treatment and graphic analysis of the data. Although there was an increase of the total consumption of water, the consumption per connection presented a drop. The model that best explained the consumption function was that of multiple coefficients. Most of the explanatory variables used were significant and their coefficient signs were also the ones expected.