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Estudo químico e histoquímico das glândulas metapleural e labial de formigas cortadeiras e a influência destas nas relações simbiontes presentes nos jardins de fungo
(Universidade Federal de São Carlos, 2015-02-18) Malaquias, Karla da Silva; Fernandes, João Batista; https://lattes.cnpq.br/2691336077459602; https://lattes.cnpq.br/9355137132419735
Leaf-cutting ants are considered the most derived insects on the planet. The performance in maintaining the aseptic conditions of the colonies is a key factor of the ecological success of these ants. Several defenses are used by ants, among them stand out chemical defense and mutualistic associations. The last of which is variable as it is dependende the species and / or environment in which they are the nests. So this article aims at a more detailed study the action of chemical defense mode, the form it manifests itself in different species of leaf-cutting ants, which have different degrees of derivation. The study was divided into two parts, the first investigated the chemical and histochemical composition of metapleural and labial glands of five species of leaf-cutting ants. Acids and hydroxy acids were identified and quantified, as main cosntituintes. These have antimicrobial action to pathogens present in the colony. The concentration and ratio of the compounds is directly related to species and variety. Histochemical analyzes revealed great similarity between species, demonstrating a relationship with the function of these glands. Enzymes that play an important role in the social order were evidenced by histoenzimáticos experiments. In the second part, as it was known the morphology of the glands, the search for inhibitors of enzymes present in the gland that provide natural protection to the colony to break the natural chemical defense. An enzyme that plays a major role in the secretion of acid is the fatty-acid synthase (FAS). At the present stage, cerulenin analogues were synthesized, known inhibitors of FAS in order to study the structure-activity relationship of these compounds.
Sentidos e significados manifestos por licenciandos e pós-graduandos ao produzirem atividades de ensino de matemática na perspectiva lógico-histórica
(Universidade Federal de São Carlos, 2015-02-18) Rezende, João Paulo; Sousa, Maria do Carmo de; https://lattes.cnpq.br/6637658562543505; https://lattes.cnpq.br/5466506680401535
This current research, of qualitative nature, has been led by the question: which senses and meanings can be produced by undergraduate and graduate students while they experience, study and create teaching activities from a logical-historical perspective? Our aim was to identify and analyze the senses and meanings manifested by two subjects that composed a group of ten undergraduate and three graduate students, who gathered virtually and in person, over a semester, to reflect collectively upon the organization of teaching by means of teaching activities founded by the logical-historical perspective. To conduct the research, we sought theoretical fundaments in the logical-historical dialectical perspective on theoretical constructs that deal with Teaching Orienting Activities (AOE in Portuguese) and with the concepts of sense and meaning studied by Vygostsky. The gatherings took place in the context of the Integration, Teaching, Research and Extension Curricular Activity (ACTEPE in Portuguese) entitled: “When the history of Mathematics becomes a teaching methodology,” and they were split in three blocks: the first was aimed at motivation to work under a logicalhistorical perspective; the second one, at the study and deep analysis of it; and the third one, at the organization of teaching activities founded by this perspective. The following instruments were used to constitute research data: a field journal; narratives; audio recording of the gatherings, which were transcribed; forums held in a virtual environment; and propositions of activities that were designed or adapted by the participants and presented in the last gatherings. Upon these propositions and three specific criteria, two participants, whose trajectories were followed along the sixteen gatherings, were selected. The senses and meanings manifested by the subjects, in the context of the present study, show that organizing teaching from a logical-historical perspective can allow the involved students to seize the concepts through the exercise of thinking about them, making it possible for the learners to feel the need for developing the concept. They also show that the conceptual nexuses - both internal and external - are important theoretical constructs when working under this perspective, for they perceive internal nexuses as those which are not made explicit to the students by a formal concept representation, but they are fundamental to understand it. This meaning makes it important to evince these nexuses to organize teaching. Nevertheless, it is necessary to learn them and history can make it possible, for it holds the conceptual development process and the product of that development.
Oxidação de monóxido de carbono sobre catalisadores à base de ferro ou manganês suportados ou trocados em zeólitas H-mordenita ou Ce-mordenita
(Universidade Federal de São Carlos, 2015-02-18) Sena, Homero Jacinto; Urquieta-González, Ernesto Antonio; https://lattes.cnpq.br/0220906938149410; http://lattes.cnpq.br/2389975677904655
The fluid catalytic cracking (FCC) is one of the most important process in the petroleum refining industry, being responsible for the increase of the yield of the most valuable light hydrocarbons. On the other hand, the FCC process generates big amounts of CO, NOx and SOx emissions. The CO emissions from the most of pollution sources are abatement using noble metal based catalysts. However, the growing demand and scarcity of those metals have caused an increase in the process cost and consequently promoting studies to find alternative catalysts with comparable efficiency and lower in cost. In this respect, the literature had presented interesting results with transitions metal catalysts. Thus, the objective of this work was to prepare exchanged or impregnated Fe or Mn on H-mordenite or Ce-mordenite, which were evaluated between 150 and 550 oC in the CO oxidation with O2, in the presence or absence of interfering compounds (water steam or SO2). The catalysts were characterized by ICP-OES, DRX, DRS-UV-VIS and Mössbauer spectroscopy. The results showed that the preparation procedures of the interchanged or impregnated Fe or Mn catalysts were adequate, and no mordenite crystallinity loss was observed. Contrary to the exchanged Fe or Mn based catalysts, those based on impregnated Fe or Mn oxides showed a important potential as catalysts in the CO oxidation with O2. Then, in the applied operational conditions the Ce-MOR/Fe10, Ce-MOR/Mn5, Ce-MOR/Mn10 e H-MOR/Mn5 catalysts were able to produce an effluent with CO content lower than 500 ppm, which is the allowed limit by the environmental regulations related with FCC units. In the presence of water steam the evaluated Fe or Mn catalysts presented activity loss that was recovered after the elimination of that interfering from the feed. Nevertheless, in the presence of SO2, the tested catalysts showed an irreversible and significantly activity loss.