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Estudos sobre a fotodegradação de poluentes catalisada por semicondutores: avaliação do papel do dopante nitrogênio na atividade de TiO2
(Universidade Federal de São Carlos, 2013-04-12) Soares, Gabriela Byzynski; Oliveira, Cauê Ribeiro de; https://lattes.cnpq.br/5321313558714462; https://lattes.cnpq.br/9466363821556466
The photodegradation of organic pollutants in water, catalyzed by semiconductors, is an important and well-known area but it is still necessary develop new materials showing visible photoactivity, in order to take advantage of solar energy. One important material that have gained attention in this field is TiO2 doped with nitrogen (N:TiO2), which absorbs in wavelengths until 450 cm-1. However, its photocatalytic activity is in discussion, and the mechanisms increasing its activity are not clear understood yet, such as when the dopant could be deleterious to the activity. Therefore, this work has as principal goal the discussion about TiO2 and N:TiO2 photocatalytic activity from consolidated literature evaluations and comparatively with electrochemical experiments, which can infer how electronic proprieties are modified in the doping process. For that, a simple method for TiO2 doping with nitrogen was developed, by modifying a polymeric precursor with urea. The predominant crystalline phase was anatase and the characterization indicated that the doping method was effective. The calcination temperature variation resulted in different N substitutional and interstitial quantities and the relation about both presented fundamental importance for the doped nanoparticles photocatalytic activity in visible light. Also, it was observed that visible activity is better associated with dye sensitizing mechanism than with oxidants radicals generation. Thus, electrochemical studies with solid electrodes produced by the same nanoparticles synthesized before (and not as thin films) were done, which showed lower less efficiencies for N:TiO2 electrode. It was also observed that the doping process reduces the semiconductor band gap energy and the Fermi level to more negatives potential values, decreasing the energetic barrier for electronic transfer between Fermi level and conduction band. These results confirmed the doping importance on the direct transfer electronic mechanism for the organic substrates over the hydroxyls radical generation mechanism, which is more common on the advanced oxidative process.
Análise etofarmacológica do labirinto em cruz elevado aberto para avaliar comportamentos defensivos e a antinocicepção induzida pelo medo em camundongos
(Universidade Federal de São Carlos, 2013-04-12) Sorregotti, Tatiani; Souza, Ricardo Luiz Nunes de; https://lattes.cnpq.br/9354501882831474
Exposure of rodents to an open elevated plus-maze (oEPM) elicits antinociception and increases plasma corticosterone levels. However, no studies have yet assessed the defensive behaviour repertoire of animals in this modified test situation. In Experiment 1, factor analysis was employed to characterise the behavioural profile of mice exposed to the oEPM. Experiments 2 and 3 assessed the effects of acute alprazolam (0.5-1.5 mg/kg), diazepam (0.5-1.5 mg/kg), pentylenetetrazole (10.0-30.0 mg/kg), yohimbine (0-6 mg/kg), mCPP (0-3 mg/kg), and acute and chronic fluoxetine (10.0-30.0 mg/kg) and imipramine (1.0-15.0 mg/kg) on the various behaviours identified in Experiment 1. Experiment 4 assesed the effect of nociceptive stimulus (formalin test) on behavioural profile of mice exposed to the oEPM. Experiment 5 evaluated the effects of alprazolam in mice exposed to the oEPM under noxious stimuli. The factor analyses revealed that behaviour in the oEPM can largely (77% total variance) be accounted for in terms of 3 factors: factor 1 ( depth exploration ; e.g. head-dipping on the arms), factor 2 ( cautious exploration of arms ; e.g. flatback approach), and factor 3 ( risk assessment ; stretched attend postures). Experiments 2 and 3 showed that, over the dose range used, alprazolam selectively attenuated all measures of defensiveness. Similar, though more modest, effects were seen with diazepam. Pentylenetetrazole decreased total entries and head dipping outside the central square, but did not change other behavioural measures. Although acute fluoxetine or imipramine treatment failed to modify behaviour in the oEPM, chronic fluoxetine (but not chronic imipramine) attenuated total flat back approach and increased head dipping outside the central square. While yohimbine decreased SAP frequency in the central square and flat-back total, mCPP increased the latter behaviour. Experiment 4 showed that effects of nociceptive stimulus were opposite effect of alprazolam: increased SAP in the proximal areas and arm-ends and decreased head-dipping in the arms. Experiment 5 replicated the effects observed in Experiment 2 (treatment with alprazolam per se). Together, the results indicate that the oEPM induces behavioural defensive responses that are sensitive to alprazolam and to formalin test.
Ecologia populacional de espécies lenhosas clonais em savana neotropical
(Universidade Federal de São Carlos, 2013-04-12) Lucena, Isabela Codolo de; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/8039678256614548
The aims of this thesis were: to investigate the heterogeneity of soils and to evaluate the contribution of clonal growth to the population dynamics of woody species under contrasting soil conditions. In the Cerrado-Pantanal ecotone (15º43 S; 56º04 W), the soil possesses typical features from both the soil of Cerrado in the Central Plateau and the soil of the Pantanal Plain. Given the variability of soil and pluviosity, our hypothesis is that clonal growth is the demographic parameter that most contributes to the population growth rate () of five woody species in this ecotone area. This study was carried out in five Cerrado areas. We identified four soil categories; three of them typic Litoplinthic Petric Plintosol, typic Dystrophic Yellow Latosol and Dystrophic Yellow Latosol with plinthite had not yet been described for the study site. The chemical attributes aluminum saturation, magnesium, calcium, pH and manganese explained 38.7% of the variability of the soils in the study sites. The spatial distribution of the edaphic attributes was heterogeneous. These attributes differed between the soils in the Cerrado Pantanal ecotone and the soils of Cerrado in the Central Plateau and of the Pantanal Plain. The population dynamics of Curatella americana, a dominant species with wide geographical distribution, was evaluated in Petric Plintosol (P) and in Yellow Latosol (L), in the dry and rainy seasons. Sexual reproduction and seedling growth were higher in P, whereas clonal growth was higher in L. The population growth rate (λ) was higher in P. The adult survival rate exerted the strongest effect on λ for the two soil categories and the dry and rainy seasons. The interaction between soil category and pluviosity exerted the strongest effect on λ. We also analyzed the dynamics of species with small populations (Bowdichia virgilioides and Roupala montana) and large populations (Curatella americana and Caryocar brasiliense), to determine which demographic parameters characterize woody clonal species with different sizes. For the species with small populations, the rate of sexual reproduction and the density of all life stages were smaller, whereas the clonal growth was higher. Small populations were more susceptible to variations in soil and pluviosity. The rates that most contributed to the λ of Bowdichia virgilioides and Roupala montana in L and P were: respectively, the survival of young ramets and immatures, in the dry season; and for both species, the survival of adults, in the rainy season. For C. americana and C.brasiliense, the survival of adults was the parameter that most contributed to λ, independently of soil category and season. The study indicated an heterogeneity of the superficial layer of the soil and of the soil categories that occur in this area. Soils with contrasting attributes exerted an important effect on the dynamics of woody clonal species. The survival of young and immature individuals, originated from clonal growth, was the rate that most contributed to the λ of the small-sized populations of woody clonal species B. virgilioides and R. montana , whereas the survival of adults was the rate that most contributed to the λ of the large-sized populations C. americana and C. brasiliense.
Produção e caracterização de material de referência de forrageira para nutrientes e contaminantes inorgânicos
(Universidade Federal de São Carlos, 2013-04-12) Bossu, Carla Maíra; Nogueira, Ana Rita de Araújo; https://lattes.cnpq.br/7034773971317045; https://lattes.cnpq.br/2789193033004313
The main aim of this work was to produce a candidate material for national reference material, the forage Brachiaria brizantha Stapf. cv. Marandu, containing known levels of contaminants (Cr, Pb, Cd, and As) and macro and micronutrients (Ca, P, Mg, K, Cu, Fe, Mn, Zn and Na). Brachiaria brizantha Stapf cv. Marandu was shown in 400 pots containing 25 kg of soil. The pots were kept in a greenhouse at Embrapa Southeast Livestock located in Sao Carlos, SP. A previous study was conducted in order to establish an appropriate concentration of contaminants that would not harm the dry matter production critically. In order to produce a reference material containing inorganic contaminants in its structure, the dose of 25 mmol/pots was chosen and added into 375 pots. The first harvest occurred after approximately 60 days of plant growth, and the second one after 120 days. Then, the samples were oven-dried at 45°C for 72 hours and grounded first in a cutting mill and then in an ultra-centrifugal mill to reduce particle size. It was produced 20 kg of dried and grounded material. After this, the homogenization and other processes were carried out, including packaging and gamma irradiation dosage in the range of 5-10 kGy to increase the shelf life. Other relevant studies were also undertaken, such as: particle size distribution, betweenbottles and within-bottle homogeneity evaluation, short and long term stability tests using ICP-MS techniques for As, Cd, Cr and Pb, and ICP OES for Ca, P, Mg, K, Cu, Fe, Mn , Zn and Na. Relative humidity and homogeneity between-bottles were also carried out using INAA. All tests presented results within the range of 95%, assuring homogeneity and stability of the candidate material for forage reference material. The consensus values for the 13 elements were determined by collaborative program. All these experiments were performed in accordance with the ISO Guides 30 to 35.
Desenvolvimento de um programa e avaliação de material autoinstrucional para formação de agentes favorecedores de comportamento de estudo
(Universidade Federal de São Carlos, 2013-04-12) Coser, Danila Secolim; Cortegoso, Ana Lúcia; https://lattes.cnpq.br/1387766161450223
The engagement of parents, and adults in general, with the academic activities of children is an important factor for establishing adequate study conditions as early as possible, avoiding that this kind of learning happens by chance, through trial and error and coercive control. Based on the behavior analysis theory and the teaching technology denominated educational programming , the current work aims to develop and evaluate an individualized material for training adults for being agents that favor the studying behavior of children. The research was divided in two phases: 1. Elaboration of teaching material, based on teaching programming procedures and knowledge gathering already available. 2. Evaluation of the material regarding its efficiency as a condition for training agents for favoring the studying behavior. At the first step the following activities were done: a. description of the problem in which intervenes through the teaching programming; b. proposal of terminal teaching objectives, which could solve the problem, in a behavior form.; c. decomposition of the terminal objectives proposed in all the necessary actions to achieve them; d. identification of the working parts and intermediary objectives; e. definition of the starting repertoire of the apprentices in a behavior manner; f. teaching objectives sequencing according to complexity levels; g. teaching and evaluation planning; h. instructions, information, texts redacting for six modules of the teaching programming. The first phase results highlights the teaching programming potential, given that, compared to other subjects of the area, the defined teaching objectives seem more complete. During the second phase of the research, five participants used different parts of the individualized teaching material for training adults for being favoring behavioral studying agents; the same participants answered an evaluation form before, during and after the exposition to the teaching programming. The retrieved data allows affirming that the teaching programming material developed in this study is adequate as self-teaching material, with personalizes rhythm and composition, with an specific selection and sequencing of teaching units to be met. The systematic evaluation of the apprentices performance during the program activities shows some aspects of the programming teaching conditions that need to be reviewed. However, the verification of the training effects was impaired by the fact that the material was applied only partially for each participant and in a period near the children school holyday, preventing the conclusion of the practical activities. Finally, it is discussed aspects that should be considerate for future researches in this topic, such as: full teaching application programming; application period for the apprentices; development of all modules foreseen in teaching programming; review of the teaching conditions regarding the applied resources, amongst others.
Grupo focal e pesquisa ação: processos norteadores na construção de práticas de cuidado nas disfunções da articulação temporomandibular em uma equipe de saúde da família
(Universidade Federal de São Carlos, 2013-04-12) Minorin, Thiago Stedile; Joaquim, Regina Helena Vitale Torkomian; https://lattes.cnpq.br/7719481657895650; https://lattes.cnpq.br/2468739112832134
Considered as a disease with chronic character and multifactorial etiology, and with intensity and duration that may vary according to the intensity of the present factors and to the interaction between these factors, the Temporomandibular Dysfunctions (TMD) may, in extreme cases, become incapacitating, or even cause the loss of working or studying days. According to researches developed in different populations, TMD present high levels of prevalence, a fact that requires more attention from the public health authorities. The treatment to this disease is more preferentially multiprofessional, therefore, the Family Health Team is the main entrance door for the patients to have access to the brazilian public health system and is a multiprofessional team, should be adequately prepared to identify, refer and follow up the cases of TMD in their territories. The presented research intended, by the application of the focal group and research-action strategies, identify and resolve the eventual lacks of knowledge concerning the TMD, helping the team to build and organize collectively this knowledge, targeting to qualify the care offered to the patients who have TMD. The participants, professionals working in the Family Health Team, were separated in groups and each group had an heterogeneous configuration referring to TMD. As a final result of this research, a flowchart has been developed by the team, with the intention of offering a better care to possible cases of patients with TMD. This step has been executed by using the tool know as Flowchart Analyzer. To achieve this result, seven meetings and a few strategies were necessary, such as: mobile visualization technic, group dinamics, expositive activity of cientific content, and daily evaluations on the work done. In conclusion, the focal group and the research-action have shown appropriate and having enough power to identify and to fill in the blanks presented by the knowledge of the team members. In addition to that, the participation on this research has been an appropriate way to acquire important knowledge that permeate the care practices that the team offers to the patients in their territory.
Flux avalanches in patterned superconducting thin films: ac susceptibility, morphology and related studies
(Universidade Federal de São Carlos, 2013-04-12) Motta, Maycon; Ortiz, Wilson Aires; https://lattes.cnpq.br/0241177338066307; https://lattes.cnpq.br/8340540626164812
Avalanches are sudden dramatic phenomena that occur in nature. The technique of magneto-optical imaging (MOI) has allowed us to observe abrupt flux entrances in superconductors, the so-called ux avalanches, due to thermomagnetic instabilities in the vortex matter. Their morphology is fascinating, especially in superconducting thin films, where they develop in dendritic patterns. From a practical point of view, the flux avalanches undermine applications of superconducting thin films. In the last years, however, several steps have been reached to fully understand the fundamental physics of the phenomenon and also on how to suppress their occurrence. The present thesis deals with the study of flux avalanches in structured superconducting thin films. We have studied crystalline Nb and amorphous Mo79Ge21 thin films decorated with arrays of antidots (ADs or holes) produced by electron beam lithography. The magnetic response of these specimens has been investigated by means of MOI, dc magnetization and ac susceptibility. Firstly, we have established a link among those three techniques in the regime dominated by flux avalanches. We have observed that the reentrant behavior in the ac susceptibility at low temperatures occurs as a consequence of flux avalanches. Essentially, there is reuse of the channels created by the first ac cycle in a regime where the signal is weakly dependent on the temperature. Our results show that measurements of ac susceptibility versus ac field amplitude can be used to detect flux avalanches, since the signature of the flux avalanches appears as noisy curves of both ac susceptibility components. As a consequence, the critical current density as a function of temperature [Jc.T ] obtained by using the Bean model whose validity is assured by Cole-Cole plots is smooth for higher temperatures and, below a certain temperature onset, a non-smooth and noisy behavior takes place due to the avalanches. The temperature dependence of Jc.T,H was determined for different values of the applied magnetic field. The stability/instability frontier was then identified as the limiting temperature below which the curve Jc.T,H becomes noisy, indicating the occurrence of avalanches. Associated with this limiting temperature, the threshold critical current density to trigger avalanches is essentially independent of the magnetic field. This frontier corresponds to the upper threshold limit for the occurrence of avalanches. The effect in a thin film of a graded distribution of ADs which follows nearly the flux profile described by the Bean model has been studied. Compared to the uniform distribution, there is an increase of the critical current density at low fields. Moreover, viii the flux avalanches, highly induced by the presence of an array of ADs, have their activity reduced in temperature and magnetic field. For the first time, flux avalanches have been visualized in amorphous Mo79Ge21 thin film, both in plain and decorated thin films. Finally, we have investigated the influence of the lattice symmetry and AD geometry on the flux avalanche morphology. We have observed avalanches with the habit of forming trees where the trunk is parallel to the main axis of the square lattice and the branches form angles of 45 degrees. In addition to that, we have found an anisotropic penetration in a Nb thin film decorated with a square lattice of triangular ADs. Besides that, a sample having one half of the ADs in the form of squares, and the other half being circles, has been observed to present avalanches of different morphologies on each of its halves. We have also studied an a-MoGe thin film with a centered rectangular 2D Bravais lattice with square ADs which shows penetrations with different angles depending on the edge. The overall features of the avalanches, and in particular the 45-degree direction of the branches, have been confirmed by numerical simulations using the thermomagnetic model. Superconductivity, structured thin films, flux avalanches, magneto-optical imaging.