Navegando por Palavras-chave "Mechanical Properties"
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- ItemSomente MetadadadosAvaliação Das Propriedades Físico-Químicas Das Amostras Cristalizadas De Efavirenz E Seu Impacto Na Formação De Comprimidos E Na Dissolução(Universidade Federal de São Paulo (UNIFESP), 2017-05-31) Oliveira, Maira Paladini De [UNIFESP]; Cuffini, Silvia Lucia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)HIV infection is a complex disease of slow and uncertain course that leads the individual to develop the acquired immunodeficiency syndrome (AIDS, or, more commonly, its acronym in English, AIDS). In view of the complexity of the disease and the need for a chronic treatment of it, the improvement in the properties of drugs for the treatment of patients is increasing. Efavirenz (EFV), a major antiretroviral therapy agent, is the most commonly used non-nucleoside reverse transcriptase inhibitor (NNRIT) in highly active antiretroviral therapy (HAART) for the treatment of adults And as part of efforts to simplify and optimize first-line treatment, the World Health Organization (WHO) has recommended EFV as the first choice. EFV is a Class II drug under the Biopharmaceutical Classification System , Which has a low solubility and high permeability, and is therefore interested in the development of strategies to increase solubility and / or dissolution, as well as to control manufacturing processes such as compression Which could modify critical parameters in the dissolution as the polymorphism, the morphology among others. Is one of the manufacturing processes that has the greatest impact on the dissolution of a drug. During this process, some physical-chemical parameters such as crystalline or polymorphic structure, morphology and particle size, microstructure, etc. are modified. In this work, the EFV solvent crystallization was carried out, varying solvents, temperatures and agitation. Thus, they obtained 27 crystallized samples and from them were made physical-chemical analyzes to evaluate the impact of these samples in relation to the polymorphism, particle size, Hausner factor, Carr index in the compression of the drug. Thus, it was found that the compression performed, given the axial force applied to the tabletting had better result for Polymorph I tablets, as well as the hardness was also higher for these tablets. And finally, it evaluated the dissolution efficiency of the tablets formed by the compressor, and having the highest rate of dissolution reached was by a tablet of Polimorph II.
- ItemAcesso aberto (Open Access)Avaliação das propriedades mecânicas de misturas de PEAD e cápsulas de café.(Universidade Federal de São Paulo, 2020-10) Oliveira, Waldir Patrick Santos de [UNIFESP]; Passador, Fabio Roberto [UNIFESP]; http://lattes.cnpq.br/0152213852695153O café é uma das bebidas mais consumidas mundialmente, mantendo milhares de admiradores ao redor do globo. O hábito de tomar café está presente no dia a dia da maioria das pessoas, muitas vezes se repetindo ao longo do dia. Devido à isso, aos avanços tecnológicos e à correria do cotidiano, em que se valoriza cada vez mais a rapidez e a praticidade, ocorreu a popularização do mercado de cápsulas no cenário mundial. Apenas no Brasil, segundo uma pesquisa da Associação Brasileira da Indústria de Café (ABIC), são consumidas anualmente cerca de 3 bilhões de cápsulas, com tendência de crescimento de 17% ao ano até 2020. O grande problema, no entanto, está associado ao descarte das cápsulas pós uso e à sua composição, pois, apesar de serem compostas basicamente de poliolefinas e alumínio dependem de um mecanismo de separação de elevada complexidade, o que dificulta o processo de reciclagem, fazendo com que o destino de grande parte dessas cápsulas seja os aterros sanitários. De acordo com o apresentado, este trabalho de conclusão de curso visa apresentar uma alternativa de reciclagem para as cápsulas de café pós uso, na intenção de minimizar o descarte inadequado, dando a elas um destino ecologicamente correto e sustentável, e com isso reduzir os impactos ambientais negativos causados. Para isso, a reciclagem das cápsulas de café foi realizada a partir de uma mistura de cápsulas trituradas, compostas majoritariamente por polipropileno (PP) e alumínio, e polietileno de alta densidade (PEAD). Para a realização do projeto, foram disponibilizadas cápsulas de café descartadas no Instituto de Ciência e Tecnologia da Universidade Federal de São Paulo (UNIFESP). As cápsulas foram lavadas e trituradas. Diferentes teores de cápsulas foram utilizados com o PEAD e o processamento foi realizado por extrusão, seguido da prensagem dos corpos de prova. As composições foram caracterizadas por ensaios de tração uniaxial, resistência ao impacto Izod e dureza Shore D. A adição das cápsulas mostrou aumentar o módulo elástico e a dureza das composições, com uma respectiva diminuição da resistência ao impacto.
- ItemSomente MetadadadosEfeito Do Tempo De Moagem E Do Tratamento Térmico Nas Propriedades Mecânicas De Compósitos De Matriz De Alumínio Aa6061 Reforçados Por Nanotubos De Carbono De Paredes Múltiplas(Universidade Federal de São Paulo (UNIFESP), 2018-02-28) Rocha, Geovana Vilas Boas Da [UNIFESP]; Travessa, Dilermando Nagle [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Carbon Nanotubes (Cnt) Are Promising Materials To Strengthen Lightweight Aluminum Matrix Composites, But Their Dispersion Into The Metallic Matrix Is Challenge, Such As The Difficulty Of A Obtaining A Homogeneous Dispersion Of The Cnt Into The Matrix And The Maintenance Of Its Integrity During The Processing Conditions. In The Addition, Addition Of Cnt May Modify The Heat Treatment Cycle. This Study Aimed To Analyze The Influence Of Milling Time And Heat Treatment On The Mechanical Properties Of Aa6061 Aluminum Alloy Matrix Composites Reinforced By Multi Walled Carbon Nanotubes (Mwcnt). The Composites Were Previously Fabricated By Powder Metallurgy Route: Mechanical Alloying (6 And 10 Hours) And Subsequently Hot Extrusion. Mwcnt Are Added Under Different Conditions: Untreated, Functionalized And Functionalized And Decorated With Ag, In 1, 2 And 4% By Weight. Samples Were Also Produced With No Reinforced Addition (Reference Sample) For Comparison Purposes. The Composites Were Analyzed Under The Conditions As E
- ItemSomente MetadadadosEstudo Das Propriedades Termomecânicas E Características Morfológicas De Grafites Sintéticos De Uso Aeroespacial(Universidade Federal de São Paulo (UNIFESP), 2017-07-31) Motta, Jose Andre Da [UNIFESP]; Rezende, Mirabel Cerqueira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)In a rocket motor with solid propulsion, the energy of the combustion reaction of chemical propellant at high pressure results in the generation of gases at temperatures in the order of 2700 °C. These extreme operating conditions lead to the search for materials with adequate mechanical characteristics around 2500 °C, good heat conductors and which are little affected by severe thermal shock. In compliance with these strict requirements, one of the materials used is the synthetic graphite. Considering that there is no available direct correlation in the literature among morphological, thermal and mechanical characteristics of synthetic graphites for space use, the present work has the objective of characterizing three types of synthetic graphites by means of mechanical tests (tensile and compression strength), physical (porosity, density and of thermal expansion coefficients and thermal diffusivity measurements) and morphological (optical microscopy) analyses. The results obtained in morphological analyses show that the studied samples are anisotropic carbon materials with very different optical textures. The analysis of the surface porosity shows values between ~2.3 and 30%, depending on the type of graphite and the radial or longitudinal position of withdrawal of the specimen in the graphite billet. The apparent density varied between 1.72 and 1.79 g/cm3. The density values obtained by helium pycnometry ranged from 2.05 to 2.14 g/cm3. These results indicate that the samples present different volumes of open pores. BET and BJH analyses confirm that the samples present a micropores distribution with different shapes. Measurements of coefficient of thermal expansion (3.58-4.64x10-6 oC-1, in the range 25-500 oC) and thermal diffusivity (~ 14-26x10-6 m2/s at 850 oC) show the influence of grain direction and also indicate that one of the samples of graphite was probably obtained by uniaxial pressing and not by extrusion. The correlation of tensile (~10 to 26 MPa) and compression (~30 to 76 MPa) strength results as a function of surface porosity shows that these properties are affected by the porosity level in a non-linear manner. The results show that the evaluation of the optical textures and the distribution of surface pores and also the tensile and compression strength are priority requirements in the selection of synthetic graphite of space use.
- ItemSomente MetadadadosEstudo Do Comportamento Em Fadiga E Corrosão Da Liga De Alumínio 7075 Submetida A Diferentes Tratamentos Térmicos E Nitretação A Plasma(Universidade Federal de São Paulo (UNIFESP), 2018-02-26) Camarinha, Maria Gabriela Galvao [UNIFESP]; Reis, Danieli Aparecida Pereira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Aluminum Alloys Found Their Main Application In Structural Components Of Airplanes, Which Present As Predominant Failure Mode The Fatigue Process. The Great Presence Of Airports In Coastal Regions Makes Relevant The Study Of The Corrosive Process Of Aluminum Alloys Since The Localized Corrosion Causes Adverse Effects On Mechanical Properties Of The Material. In Order To Improve The Fatigue And Corrosion Behavior Of 7075-T6 Aluminum Alloy, This Work Evaluated And Compared The Effect Of Rra Thermal Treatment And Plasma Nitriding On The Mechanical And Corrosion Properties Of The Aa7075-T6 Alloy. Studies Were Carried Out Under Conditions Of Tensile Fatigue (R = 0.1), With Smooth And Notched Test Bodies, And Corrosion In 0.6 M Nacl Medium At 25 ° C And Ph~6. Microstructural And Aln Layer Analyzes Were Performed Using Optical Microscopy, Scanning And Transmission Electron Microscopy, Profilometry And Notch Sensitivity. The Microstructural Analysis Showed That The Rra Heat Treatment Maintained The Microstructure Wit
- ItemSomente MetadadadosExperimental characterization of the mechanical properties of railway wheels manufactured using class b material(Edicoes Loyola, 2016) Soares, H.; Zucarelli, T. [UNIFESP]; Vieira, M.; Freitas, M.; Reis, L.The railway system has an important role in developed countries, it is possible to see, nowadays, passenger trains crossing the Old Continent and achieving impressive speeds in the East