Ensaios mec��nico e aplica����o da l��gica fuzzy para avalia����o do canote do garfo

A inova����o tecnol��gica tem sido um dos fatores fundamentais que levam grandes empresas a permanecerem no topo do ranking mundial do mercado globalizado, de acordo com o avan��o tecnol��gico o setor de engenharia tem buscado solu����es que ofere��am resultados positivos em prol do crescimento de sua empresa ou organiza����o. Métodos de simulação para avalia����o do comportamento mec��nico de produtos submetidos a cargas est��ticas e cargas din��micas s��o extremamente necess��rias para redu����o dos custos de fabrica����o dos produtos. O uso de ensaios mec��nicos e virtuais �� de vital import��ncia para avalia����o do produto. O presente trabalho teve como objetivo a utiliza����o da l��gica fuzzy em um produto chamado canote do garfo da bicicleta, onde foi analisado al��m do grau de pertin��ncia variado entre 0 e 1, o grau de veracidade tamb��m variado entre 0 e 1, tendo como foco principal o comportamento do produto canote do garfo e sua valida����o.

Desenvolvimento de pain��is confeccionados a partir de fibras de coco para controle ac��stico de recintos

Uma boa alternativa para o controle de ru��do em ambientes fechados �� a utiliza����o de materiais de absor����o sonora, onde parte da energia ac��stica �� transformada em energia t��rmica atrav��s da viscosidade do ar, o que ocorre tanto em materiais porosos quanto fibrosos. A caracter��stica de absor����o ac��stica de um material �� determinada pelo coeficiente de absor����o sonora que depende principalmente da freq����ncia, ��ngulo de incid��ncia do som, densidade, espessura e estrutura interna do material. Da Amaz��nia, devido a sua sobrepujante biodiversidade, s��o retirados milhares de produtos e subprodutos naturais, alguns dos quais n��o s��o totalmente aproveitados. Dessa forma, muitos res��duos chegam a outros setores industriais, como �� o caso da fibra de coco que �� utilizada das mais diversas formas. Assim, o presente trabalho define e descreve um processo de fabrica����o de pain��is ac��sticos, a partir da fibra de coco, com a determina����o experimental dos principais par��metros visando o controle ac��stico de recintos, al��m de desenvolver um modelo num��rico para estabelecimento de par��metros de controle de qualidade e custo, que auxiliem no desenvolvimento e na fabrica����o de novos pain��is. Primeiramente, s��o coletadas as informa����es necess��rias para iniciar o processo de desenvolvimento dos pain��is de fibra de coco, seguindo uma metodologia de desenvolvimento de produto, baseada no ���projeto informacional���. Em seguida, s��o descritas todas as etapas do processo de fabrica����o destes pain��is, para posterior obten����o de suas principais propriedades f��sico-qu��micas, mec��nicas e ac��sticas. Com as simula����es num��ricas, buscou-se analisar e predizer o comportamento de um painel de fibra de coco (al��m de um painel de espuma comercialmente dispon��vel), e investigar a sua influ��ncia sobre os par��metros ac��sticos de um audit��rio (tempo de reverbera����o, decaimento da press��o sonora e inteligibilidade). Com o desenvolvimento dos pain��is pretende-se contribuir para a cria����o de novos setores na economia do estado, principalmente quando se considera o alto custo dos pain��is comercializados no sul do pa��s. Finalmente, outra vantagem significativa �� a possibilidade da utiliza����o destes pain��is dentro do contexto das linhas arquitet��nicas regionais, onde s��o real��ados os materiais da pr��pria regi��o.

Movimenta����o dos dentes artificiais em pr��teses totais com diferentes profundidades de palato

P��s-gradua����o em Odontologia - FOA

Controle da porosidade e das caracter��sticas ��cido-base de ��xidos mistos derivados da hidrotalcita para aplica����o em cat��lise

P��s-gradua����o em Qu��mica - IQ

Aluminas macro-mesoporosas produzidas pelo m��todo sol-gel para aplica����o em cat��lise heterog��nea

P��s-gradua����o em Qu��mica - IQ

S��ntese e caracteriza����o da MOF NH2-MIL-125(Ti) e sua aplica����o como catalisador na rea����o de condensa����o de Knoevenagel

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

S��ntese de aluminas macro-mesoporosas pelo m��todo sol-gel acompanhado de separa����o de fases

P��s-gradua����o em Qu��mica - IQ

Estrutura e algumas propriedades ��pticas de difenilfosfinatos de terras-raras

Coordination compounds of trivalent lanthanides cations with diphenylphosphinate are originated from direct reaction between a lanthanide salt and diphenylphosphinic acid. These complexes have peculiar and intriguing features, as (i) quickly obtainment through wet process precipitation, (ii) appreciable thermal stability, similar to inorganic phosphates, (iii) polymeric structure, and consequently, (iv) low solubility in both polar and non-polar solvents. Nowadays, coordination polymers are classified as coordination networks or, in case of porous materials, as metal-organic frameworks (MOFs). By this study, we aim to determine some optical properties of rare-earth diphenylphosphinate (RE = La3+, Eu3+, Gd3+, Lu3+) and conduct an updated classification of these compounds, bringing more details of its structure and the possible proposal of new materials with applications in lighting, detection of ionizing radiation and magnetism. The complexes of trivalent rare-earth cation with diphenylphosphinate were prepared by direct mixture of diphenylphosphinic acid with rare-earth metal chloride, both in ethanolic solution. The solution of diphenylphosphinic acid was kept in a beaker under constant stirring with pH measurements of the solution and gadolinium chloride solution was then dripped slowly with the aid of a burette until its complete addition; the following metal:ligand molar ratios were tested: 1:1, 1:2, 1:3, 2:1 e 3:1. The compounds were characterized by spectroscopic and structural techniques. By Fourier Transform Infrared Spectroscopy (FT-IR), it was possible to check the total ionization of diphenylphosphinic acid in synthesized complexes, confirmed by the absence of the band type A, B, C related to ��(O-H) of the acid (2663 cm-1, 2168 cm-1, 1684 cm-1), as well as the disappearance of ��(P-OH)=961 cm-1. Furthermore, the occurrence of bands shifts of ��(POO-) [symmetrical and asymmetrical] of...

Estrutura e algumas propriedades ��pticas de difenilfosfinatos de terras-raras

Coordination compounds of trivalent lanthanides cations with diphenylphosphinate are originated from direct reaction between a lanthanide salt and diphenylphosphinic acid. These complexes have peculiar and intriguing features, as (i) quickly obtainment through wet process precipitation, (ii) appreciable thermal stability, similar to inorganic phosphates, (iii) polymeric structure, and consequently, (iv) low solubility in both polar and non-polar solvents. Nowadays, coordination polymers are classified as coordination networks or, in case of porous materials, as metal-organic frameworks (MOFs). By this study, we aim to determine some optical properties of rare-earth diphenylphosphinate (RE = La3+, Eu3+, Gd3+, Lu3+) and conduct an updated classification of these compounds, bringing more details of its structure and the possible proposal of new materials with applications in lighting, detection of ionizing radiation and magnetism. The complexes of trivalent rare-earth cation with diphenylphosphinate were prepared by direct mixture of diphenylphosphinic acid with rare-earth metal chloride, both in ethanolic solution. The solution of diphenylphosphinic acid was kept in a beaker under constant stirring with pH measurements of the solution and gadolinium chloride solution was then dripped slowly with the aid of a burette until its complete addition; the following metal:ligand molar ratios were tested: 1:1, 1:2, 1:3, 2:1 e 3:1. The compounds were characterized by spectroscopic and structural techniques. By Fourier Transform Infrared Spectroscopy (FT-IR), it was possible to check the total ionization of diphenylphosphinic acid in synthesized complexes, confirmed by the absence of the band type A, B, C related to ��(O-H) of the acid (2663 cm-1, 2168 cm-1, 1684 cm-1), as well as the disappearance of ��(P-OH)=961 cm-1. Furthermore, the occurrence of bands shifts of ��(POO-) [symmetrical and asymmetrical] of...

Metal-free catalysts derived from lignin for efficient wet peroxide oxidation

In this work, a wheat and hemp lignin (Sarkanda, Granit S.A.) has been used as raw material for the development of metal-free activated carbons. These materials were tested in the catalytic wet peroxide oxidation (CWPO) of 4-nitrophenol (4-NP; 5 g L-1) during 24 h experiments conducted at relatively mild operating conditions (p = 1 atm, t = 50 ��C, pH = 3, catalyst load = 2.5 g L-1 and [H2O2]0 = 17.8 g L-1). First, the lignin was carbonized under N2 atmosphere followed by the activation of the obtained non-porous carbon (LG) under air atmosphere at different temperatures (150 to 350 ��C), leading to the generation of significant porosity.

Development of magnetic carbon xerogels for catalytic wet peroxide oxidation

Hybrid magnetic carbon composites have been recently proposed as the next step in the evolution of catalysts for catalytic wet peroxide oxidation (CWPO), with several synergistic effects arising from the combination of the high catalytic activity of metal species with the proven catalytic properties of carbon-based materials in CWPO [1]. Bearing this in mind, this work sought the development of novel magnetic carbon xerogels, composed by interconnected carbon microspheres with iron (Fe) and/or cobalt (Co) microparticles embedded in their structure. As inferred from the extensive characterization performed, materials with distinctive properties were obtained upon inclusion of different metal precursors during the sol-gel polymerization of resorcinol and formaldehyde, followed by thermal annealing.

Jogos de neg��cio : o que leva o docente de cursos da ��rea de Ci��ncias Sociais Aplicadas a adotar a ferramenta de ensino

The Business Games are a growing teaching strategy and alternative to the academic front through the new process of Teaching and Learning. Through literature review and semi-structured interviews, this work addresses the teachers considering their subjectivity in deciding JN as the three profiles suggested by Faria and Wellington (2004): those who use it, those who stopped using and those who do not. The research corpus is limited to contributions of 22 respondents between master and doctors teachers of Applied Social Sciences area courses in colleges of Bras��lia (DF), Goi��nia (GO), Ribeir��o Preto (SP) and Uberlandia (MG). The content analysis of the interviews allowed to infer that: (1) join the teaching strategy is a commitment to a complex planning, with constant training and proactivity related to student feedback; (2) abandons the practice is becoming less common, because managers tend to recommend it and there are more and more software available for specific disciplines. Its discussed also other contributions (motivations) given by respondents of the three groups that were not found in the literature. It is hoped that this work will serve (1) incentive to teachers on the use of Business Games as a teaching strategy (2) consultation by managers when they decide about purchasing simulation software. Finally, stands out that the educational success of JN depends not only on the various motivations of teachers, as well as the interest and commitment of the student.

Uma janela tropical: an��lise do desempenho luminoso de ambientes com aberturas sombreadas para o clima de Natal/RN

This master thesis introduces assessment procedures of daylighting performance in office rooms with shaded opening, recommendations for Natal-RN (Latitude 05,47' S, Longitude 35,11' W). The studies assume the need of window exterior shading in hot and humid climate buildings. The daylighting performance analyses are based on simulated results for three levels of illuminance (300,500 e 1000 lux) between 08h00 e 16h00, in rooms with 2,80 m height, 6 m large and 4 m, 6 m e 8 m depths, with a centered single opening, window wall ratio (20%, 40% e 60%), four orientations (North, East, South and West), and two types of sky (clear and partially cloudy). The sky characteristics were statistically determined based on hourly data from INPE-CRN solar and daylighting weather station. The lighting performance is resulted from dynamic computer simulation of 72 models using Troplux 3.12. The simulation results were assessed using a new parameter to quantify the use of interior daylighting, the useful percentage of daylight (PULN), which corresponds to the time fraction with satisfactory light, in accordance with the illuminance design. The passive zone depths are defined based on the PULN. Despite the failures of illuminance data from the weather station, the analyses ratified the high potential of daylighting for shaded rooms. The most influential variables on the lighting performance are the opening size and the illuminance of design, while the orientation is a little influential

M��ltiplas antenas como alternativa para aumentar a taxa de extra����o de chaves secretas em redes veiculares com desvanecimento lento

The communication in vehicular ad hoc networks (VANETs) is commonly divided in two scenarios, namely vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I). Aiming at establishing secure communication against eavesdroppers, recent works have proposed the exchange of secret keys based on the variation in received signal strength (RSS). However, the performance of such scheme depends on the channel variation rate, being more appropriate for scenarios where the channel varies rapidly, as is usually the case with V2V communication. In the communication V2I, the channel commonly undergoes slow fading. In this work we propose the use of multiple antennas in order to artificially generate a fast fading channel so that the extraction of secret keys out of the RSS becomes feasible in a V2I scenario. Numerical analysis shows that the proposed model can outperform, in terms of secret bit extraction rate, a frequency hopping-based method proposed in the literature.

Protocolo de roteamento para redes oportunistas utilizando otimiza����o por enxame de part��culas

In this research work, a new routing protocol for Opportunistic Networks is presented. The proposed protocol is called PSONET (PSO for Opportunistic Networks) since the proposal uses a hybrid system composed of a Particle Swarm Optimization algorithm (PSO). The main motivation for using the PSO is to take advantage of its search based on individuals and their learning adaptation. The PSONET uses the Particle Swarm Optimization technique to drive the network traffic through of a good subset of forwarders messages. The PSONET analyzes network communication conditions, detecting whether each node has sparse or dense connections and thus make better decisions about routing messages. The PSONET protocol is compared with the Epidemic and PROPHET protocols in three different scenarios of mobility: a mobility model based in activities, which simulates the everyday life of people in their work activities, leisure and rest; a mobility model based on a community of people, which simulates a group of people in their communities, which eventually will contact other people who may or may not be part of your community, to exchange information; and a random mobility pattern, which simulates a scenario divided into communities where people choose a destination at random, and based on the restriction map, move to this destination using the shortest path. The simulation results, obtained through The ONE simulator, show that in scenarios where the mobility model based on a community of people and also where the mobility model is random, the PSONET protocol achieves a higher messages delivery rate and a lower replication messages compared with the Epidemic and PROPHET protocols.