Navegando por Data de Publicação, começando com "2010-06-29"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 4 de 4

Partilha de polinizadores por espécies quiropterófilas em um fragmento de Cerrado, São Paulo
(Universidade Federal de São Carlos, 2010-06-29) Teixeira, Reinaldo Chaves; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/0597199857360007
Flowering plants need some external pollen vectors to accomplish sexual reproduction. For plants, the access of sexual mates by pollinators agents is a limiting factor, wich make pollen vectors a critical resource for plants to reproduce successfully. Simpatric plants that share the same pollination guild avoid direct competition differing the pollinators use mode. These thesis investigate in a cerrado community the coexistence mechanisms between plant species that use the same pollinators guild, the bats. The work was carried out in a cerrado area in Brazilian southeast, between July, 2007 and June, 2009. First of all, I assessed the chiropterophilous species composition in the area, describe the floral biology and the interactions with their flower visitors. I found nine species framed in the chiropterophily syndrome, and which the flowers received visits mainly from the bat Glossophaga soricina (except in Irlbachia alata). The species flowers are adjusted to the bats morphology, ethology and physiology, and offer flowers all year long, assuring food for the bats. Then I verify the mechanisms that allow the chiropterophilous species coexistence or the facilitative interactions in the area by pollinators share. I assess the floral characteristics, blooming phenology, nectar attributes and floral visitors. Nine plant species share similar floral characteristics that are noted by the bats sense, which play as facilitative interaction between species, which produces a single floral display for attract the pollen vector in common. However, the plant species differ in the places for pollen deposition in the bats body due to differing in floral morphology, species offered distinct nectar volume and concentration which may select/segregate the pollinator and share the pollinator use during the year by flowering at different moments, which allows species that share pollinators to coexist. At last, I checked how two species in the same genus and that use the same bats as pollinators differ in the way to use the same pollen vector. I estimate the bats role in the plants species floral biology and if the species differ in floral characteristics, nectar attributes and secretion time, flowering period. I verified that group - flowers with different size shall avoid pollen mixture among species, nectar with distinct soluble concentration shall attract higher number of visitors in distinct moments, massive flowering in different periods and sequentially, allows the Bauhinia holophylla and B. longifolia coexistence in the area, even sharing the G. soricina use as main pollinator.
Cultura e nação brasileiras no discurso da reforma de Estado: a nova burocracia paulista e a modernização do Estado
(Universidade Federal de São Carlos, 2010-06-29) Silva, Victor Hugo Fischer Ribeiro da; Leirner, Piero de Camargo; https://lattes.cnpq.br/6682239833879808
Modelagem de sistemas de manufatura usando Redes de Petri Coloridas Fuzzy focando a solução de conflitos
(Universidade Federal de São Carlos, 2010-06-29) Sgavioli, Mayra; Kato, Edilson Reis Rodrigues; https://lattes.cnpq.br/8517698122676145; https://lattes.cnpq.br/6722587587201794
A Flexible Manufacturing System is a production system where more than one event can occur simultaneously in parallel, asynchronously or concurrently. These are designed to meet the needs of the market, demand for improved product quality, lower costs and shorter delivery times. Due to the complexity and flexibility of these systems, conflicts can occur when more than one process requests the same resource, such as machines or AGVs, or when a product can be produced in more than one production routing. Thus, a conflict resolution policy is needed in this type of environment. This study uses Fuzzy Coloured Petri Nets for modeling a manufacturing system. The manufacturing system is modeled considering the resources, buffers, production routings, AGV routes and identifying conflict points. The conflict resolution is performed considering both information on the shop floor and production management. Fuzzy rules are constructed to prioritize conflicting processes and a fuzzy rule-based system is modeled on Fuzzy Coloured Petri Nets in the same network as the manufacturing system, making the model of the system independent of other systems of support for the resolution of conflicts. In this work we considered the conflicts that can occur when loading and unloading station and the input and output buffer. According to the source of conflict, a rule base is shaped to assign priorities to processes. From this model it is possible to make the control system and ensure that identified conflicts are resolved.
Desenvolvimento de ligas de Mg em formas maciças para armazenagem de hidrogênio
(Universidade Federal de São Carlos, 2010-06-29) Lima, Gisele Ferreira de; Kiminami, Claudio Shyinti; https://lattes.cnpq.br/5443002033733395; https://lattes.cnpq.br/9313100199075545
In the present work, bulk magnesium metallic hydrides (MgH2 and Mg2FeH6) were produced. Commercially pure Mg and mixtures of 2Mg-Fe were processed by severe plastic deformation (SPD) by using High Pressure Torsion (HPT) method, and also by hot extrusion. Studies were accomplished with relationship to the possibility of bulk hydrides production from those materials. Also, it was evaluated the influence of the obtained microstructure from different processing conditions and also the influence of the iron in the hydrogen sorption properties. It was verified that cycles of hydrogenation do not cause bulk disintegration in any samples. The formation of Mg2FeH6 was verified in all samples of the 2Mg-Fe mixtures. This hydride is known by the difficulty of synthesizing. In spite of the excellent results regarding the hydrogenation properties improvement and, in the ability to resist superficial oxidation, a large limitation still exists regarding the use of these results in automotive applications. Bulk hydrides were produced following the conditions studied in this work, however the kinetics is still reasonably slow and the operational temperatures are still high. This fact takes to the consideration of the verification of others possibilities of application types. In the current state of this work, the most probable application is in the static storage of hydrogen, where such problems are not so significant.