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Análise de pavimentos de edifícios em concreto préfabricado considerando o efeito diafragma
(Universidade Federal de São Carlos, 2012-02-13) Raymundo, Henrique; Carvalho, Roberto Chust; https://lattes.cnpq.br/3633394168236221; https://lattes.cnpq.br/1811900837627447
One of the main differences in the structures composed of prefabricated elements of the conventional structures (cast in situ) refers to the way of how structural elements are connected together. The operation of such links is essential to perform an accurate analysis of stability and removed from these buildings. A place where the connection is very important in verifying the structural behavior is among the cellular elements of the slab. In a conventional structure, usually made of solid slabs for floors, it is observed that the behavior of slabs have a great influence on the distribution of efforts arising from actions horizontal resistance between the porch and, consequently, the stability of the same. This phenomenon, defined as a rigid diaphragm, can also be found in precast buildings, with floors composed of hollow core slabs. In order to verify the necessity of including some details of connection between the slab elements (joints between the slabs and among other things) will be proposed in this paper the analysis of five structures with different characteristics, considering the different possibilities of bracing and disposal of prefabricated slabs in the floor. Consideration will be given the difference in the distribution efforts of the pavements, considering the application of shear walls and gateways, as well as the provision of slabs parallel and perpendicular to side action. The interference of the cover structure will also be analyzed in a number of examples. From a modeling specific to the floors of these buildings and different situations with different levels of horizontal actions, one can determine the stresses at specific points of the same, thus indicating the types of reinforcements to be willing to actually floors act as a diaphragm. Finally, we intend to discuss the organization of prefabricated elements interfere in the distribution of efforts on the pavement (joints between the slab elements), based on different amounts of reinforcing bars of each type of pavement structure will require.
Avaliação do consumo de bactérias pelo zooplâncton em um reservatório eutrófico raso (Reservatório do Monjolinho São Carlos SP)
(Universidade Federal de São Carlos, 2012-02-13) Hisatugo, Karina Ferreira; Seleghim, Mirna Helena Regali; https://lattes.cnpq.br/5998337634888263; https://lattes.cnpq.br/6799589581281644
Bacteria, found in terrestrial and aquatic environments, besides their important role in organic matter decomposition and nutrient cycling, are a food source for organisms of the higher trophic levels in the food chain, such as protozooplanktonic and metazooplanktonic organisms. This study aimed to evaluate the relative importance of protozooplanktonic (ciliates and heterotrophic nanoflagellates) and metazooplanktonic organisms (rotifers, cladocerans and copepods) as bacterial consumers throughout a year, which included a rainy and a dry season, in a eutrophic environment (Monjolinho reservoir-SP) by quantifying their ingestion rates. For this purpose, grazing experiments were carried out bimonthly during one year at the sub-surface of a central station of the reservoir using fluorescently labeled bacteria (FLB) dyed with DTAF. In each survey, besides the experiments, limnological (pH, dissolved oxygen, temperature, conductivity, water transparency and nutrients) and biological (chlorophyll-a and phaeophytin concentrations, bacterioplankton, protozooplankton and metazooplankton density) water parameters were also sampled. The heterotrophic nanoflagellates (HNF) showed higher population ingestion rates than the ciliates in dry and rainy seasons, and the HNF smaller than 5μm were the main consumers of bacteria. Among the metazooplanktonic organisms, the rotifers dominated the bacterial ingestion, and the organisms belonging to the genus Filinia and Keratella and to the families Testudinellidae and Brachionidae were the main bacterial consumers. Besides ingesting bacteria, however, protozoa and rotifers population also seemed to be controlled by cladocerans and copepods predation, which, in turn, seemed to be regulated by predation of larger organisms, such as small vertebrates. Thus, the predation control (top-down) occured both on bacterial communities and protozooplanktonic and metazooplanktnic communities and bacteria were regulated both by direct and indirect predation of zooplanktonic population. The resources control (bottom-up) semmed to be higher during the dry season, while in the rainy season bacterial communities were more controlled by predation. The greatest impact on bacterial communities was caused by HNF and ciliates during the rainy season and by HNF and rotifers during the dry one.
Compostos com potencial alelopático em Aristolochia esperanzae O. Kuntze
(Universidade Federal de São Carlos, 2012-02-13) Jatoba, Luciana de Jesus; Perez, Sonia Cristina Juliano Gualtieri de Andrade; https://lattes.cnpq.br/9973185407856723; https://lattes.cnpq.br/1762622258880441
ABSTRACT Allelopathy is defined as any process involving secondary metabolites that influence the growth and development of natural and cultivated systems. Plants of the Aristolochia genus are known for their use in traditional medicine, but few studies have been conducted on the ecological importance of their secondary compounds and their possible application in agriculture. This study aimed at the isolation, characterization and evaluation of the allelopathic activity of A. esperanzae secondary metabolites. Extraction, bioassay-guided isolation, spectroscopic and spectrometric analysis of the isolated compounds was carried out. The phytotoxic activity of the active extracts from A. esperanzae different organs on the development of species of cultivated crops and weeds, and of the active semipurified sample in the initial growth of Triticum aestivum L. (wheat) was evaluated. The EtOAc extracts of A. esperanzae mature leaves and roots showed phytotoxic activity similar to the herbicide used as control over the weed species. Biossayguided isolation of compounds with allelopathic activity from mature leaves of A. esperanzae has led to the isolation of three isomeric compounds with mass fragments with m/z 321 Da and 161 Da, and ultraviolet absorption at 234 nm and between 286 nm and 287 nm. Analysis by 1D- and 2D-NMR of one of these compounds allowed to stabilish its partial structure. The semi-purified ISO sample, obtained from A. esperanzae mature leaves and composed mainly by the isomeric mixture isolated, showed allelopathic activity on the early development of wheat, with inhibition of root development and formation of necrotic abnormalities over the shoots of these seedlings, with hormetic behavior. The activity of the compounds present in the ISO fraction showed to be different from that presented by the commercial herbicide, and may lead to the development of bioherbicides..
Álgebra e formação docente : o que dizem os futuros professores de matemática
(Universidade Federal de São Carlos, 2012-02-13) Pires, Flávio de Souza; Sousa, Maria do Carmo de; https://lattes.cnpq.br/6637658562543505; https://lattes.cnpq.br/4768933864136828
The main object of this study is the analysis of some speeches from a group of future Mathematics teachers from São Carlos, São Paulo State, in relation to algebraic language teaching in Basics Education. The question which led to the development of this research was to investigate what future Mathematics teachers say about the algebraic language in Basics Education based on their past and actual perception of their under graduation course. This qualitative research has foundation in an analytical-descriptive nature. The data collection was carry out by students group participation of Mathematics Degree from São Carlos, São Paulo State, whom had already taken part of an internship program in Basics Education. The data analysis was accomplished through future teachers written statements on a questionnaire disposed into categories. The mixed questionnaire was compounded by three distinct moments: the first involved some aspects concerning Algebra, Algebraic Thought and Algebraic Teaching; the second brought more specifically the movement of teacher s formation; and the third tried to identify the future teachers profile. From these statements we could identify some difficulties with algebra learning from future teachers since Basics Education, which was reinforced along academic life in Higher Education. Besides, we noticed future teachers worry about teaching when they compare scholar and academic algebra to their own learning experiences, indicating dissociation between them.
Estrutura da comunidade microbiana e a importância da bacterivoria por protozoários em uma represa subtropical (Represa do Lobo, SP, Brasil)
(Universidade Federal de São Carlos, 2012-02-13) Mansano, Adrislaine da Silva; Seleghim, Mirna Helena Regali; https://lattes.cnpq.br/5998337634888263; https://lattes.cnpq.br/0101649577482109
Planktonic bacteria play important role in the organic matter decomposition, nutrient cycling and as food for organisms of higher trophic levels such as flagellates and ciliates, thus representing fundamental components in planktonic food webs. This study analyzed the microbial community structure and evaluated the importance of heterotrophic nanoflagellates (HNF) and ciliates bacterivory in a subtropical environment predominantly mesotrophic (Lobo-Broa reservoir, Brazil) by the quantification of their ingestion rates during one year period. The in situ experiments using fluorescently labelled bacteria (FLB) were conducted on the surface of two sampling points that have different trophic degrees. In parallel, physical, chemical and biological water variables were also evaluated. The ciliates showed a higher specific ingestion rate of bacteria (3,3 x 103 bact ind-1 h-1) than HNF (79,7 bact ind-1 h-1) due to differences in size and food acquisition among the two protozoans. The ingestion rates for both ciliates and HNF were always higher in the point 2 (P2) probably due to the higher water temperatures, which accelerate the protozoans metabolism, and higher bacterial densities. Concerning total protozoan bacterivory, the HNF populations had the greatest grazing impact (60%) on the reservoir bacterial community, especially the HNF smaller than 5 μm. The data showed that HNF grazing, in addition to regulation the bacteria abundance, probably also induced changes in the bacterial community structure, such as increasing bacterial filaments numbers and size. The ciliates contributed significantly to the bacterivory, especially in P2, where high densities and ingestion rates were verified. The main ciliate consumers of bacteria were from Spirotrichea, Peritrichia, Haptoria and Scuticociliatia groups. The bottom-up control was more important in the dry season and the top-down control was more important in the rainy one. Thus, in an annual basis, the resource availability and protozoan predation are equally important to the bacterial abundance regulation in the Lobo reservoir.
Produção e caracterização de recobrimentos de aço, empregando a liga amorfizável Fe-Cr-Nb-B
(Universidade Federal de São Carlos, 2012-02-13) Melle, Ana Karla; Kiminami, Claudio Shyinti; https://lattes.cnpq.br/5443002033733395; https://lattes.cnpq.br/5690810293811991
The equipments used to oil flow are submitted in an aggressive environment with the presence of hydrogen sulphide, carbon dioxide and sand, which contribute to corrosion and wear of the surface. To resist of these requests one alternative is the inner coating using materials with high properties of corrosion and wear. Amorphous coatings iron based have good prospects for this application. These alloys, beyond high properties, are low cost system and, therefore, they are viable economically. In this context, the aim of this work is the production and the characterization of coatings, using the amorphous alloy Fe60Cr8Nb8B24 (%at), with special focus on hardness and wear properties. Initially, preliminary studies were made for the evaluation of glass forming ability for selected composition and the influence of impurities on this behavior. The second step of this work was the production of coatings through two different routes. The first was thermal spraying process LVOF (low velocity oxygen fuel), with utilization of two distinct raw materials: (i) amorphous powders produced by atomization and (ii) amorphous powders made by high energy milling. In the other route, coatings were manufactured by spray forming process using prelayer of nickel alloys, whose aim was to allow the adhesion of particles on the substrate. All coatings produced were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wear and hardness tests and porosity and oxygen content measurements. The results shown the feasibility of production of amorphous coatings by the two routes analyzed, with interesting properties when compared to conventional materials.