Viscometry
Mostrando 1-12 de 36 artigos, teses e dissertações.
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1. Effect of shrimp shells milling on the molar mass of chitosan
Abstract Shrimp shells are a raw material rich in chitin, a precursor of chitosan biopolymer. The variables of processing (demineralization, deproteination and deacetylation) can be manipulated to determine the main characteristics of chitosan, the degree of deacetylation (DD), and average molar mass. This study evaluated the influence of one of the unit ope
Polímeros. Publicado em: 2017-03
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2. The effect of gamma radiation on mechanical properties of biodegradable polymers poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
Brazilian poly(3-hydroxybutyrate), P(3-HB), and its copolymer, poly (3-hydroxybutyrate-co-3-hydroxyvalerate), P(3-HB-co-3-HV) were irradiated with gamma radiation (60Co) at room temperature and in the presence of oxygen. The viscosity-average molar mass (Mv) was analyzed by viscometry using an Ostwald-type capillary viscometer. Both polymers showed a decreas
Mat. Res.. Publicado em: 11/12/2012
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3. Determining the viscous behavior of non-Newtonian fluids in a flume using a laminar sheet flow model and Ultrasonic Velocity Profiling (UVP) system
The flow of non-Newtonian fluids in rectangular open channels has received renewed interest over the past number of years especially as large flumes are being used to transport tailings in countries like Chile. The effect of yield stress on the flow behavior is complex and not yet fully understood. The Ultrasonic Velocity Profiling (UVP) technique has been u
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-09
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4. Solution properties of a hydrophobically associating polyacrylamide and its polyelectrolyte derivatives determined by light scattering, small angle x-ray scattering and viscometry
Uma poliacrilamida hidrofobicamente modificada e dois dos seus derivados parcialmente hidrolisados, contendo grupos hidrofóbicos e carboxila, foram preparados por polimerização micelar e pós-hidrólise. A massa molar, o segundo coeficiente do virial e o raio de giração foram determinados por espalhamento de luz estático (SLS). O espalhamento de luz di
Journal of the Brazilian Chemical Society. Publicado em: 2011-03
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5. Estudo Viscosimétrico de Soluções de Pré-Polímeros Uretânicos à Base de Poli(Glicol Propilênico) e Diisocianato de Isoforona. / Viscometric study of urethanic prepolymers based on poly(propylene glycol) and isophorone diisocyanate.
Neste estudo, o comportamento em solução diluída de pré-polímeros uretânicos à base de poli(glicol propilênico) (PPG) e diisocianato de isoforona (IPDI) foi avaliado por medidas viscosimétricas a 30 C em dois tipos de solventes, com diferentes polaridades: isopropanol e tolueno. Os pré-polímeros foram sintetizados em massa, ou seja, na aus
Publicado em: 2006
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6. UTILIZAÇÃO DE PARÂMETROS REOLÓGICOS PARA VERIFICAR A APTIDÃO AO DESAGUAMENTO DE LODOS DE UMA ESTAÇÃO DE TRATAMENTO DE ESGOTOS DO TIPO UASB + BFs CONDICIONADOS COM POLIELETRÓLITOS
This research aims at the rheological description of the sludge produced by an UASB + BAF wastewater treatment works and evaluates the application of the rheological parameters on the selection of polyeletrolyts, and its optimal dose, used to increase the sludges dehydration ability. The tests with raw sludge included rotational rheo-viscosimetry, cup with a
Publicado em: 2003
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7. Evaluation of the red cell deformability through ektacytometry in iron deficiency / Avaliação da deformidade eritrocitária através da ectacitometria na deficiência de ferro
The deformability allows the 7 to 8 cm red cell to circulate through capillaries of 3 cm. This phenomenon depends on cellular geometry, internal viscosity and viscoelastic properties of the membrane. Among the various techniques of erytrocyte deformability (ED) analysis such as: micropipette aspiration, filtration and reoscopy, we chose ektacytometry. This t
Publicado em: 2002
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8. Drenagem de espumas usadas em incendios classe B : influencia da presença de polimeros redutores de atrito hidrodinamico
Poly(ethylene oxide), PEO, is one of the most efficient drag reducing polymers. Its application in foam jels for fire-fighting can improve and even assure the fighting efficiency. In order to evaluate the viability of the application of PEO in foams of high stability used in class B fires (inflammable liquids), the effect of the polymer on the stability of f
Publicado em: 1997
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9. Caracterização de latex poliestirenicos por centrifugação em gradiente de densidade
This thesis contains five parts: Synthesis of polystyrene and poly[styrene-co-(acrylic acid)] latices, containing the basic information on emulsion polymerization together with the procedures used in this work, in the synthesis of PS and PSAA latices. Characterization of the latices of polystyrene and poly[styrene-co-(acrylic acid)], where the products of sy
Publicado em: 1994
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10. Precipitação de parafina em misturas de petroleo : medidas experimentais e modelagem termodinamica
The appearance and development of a solid-phase in the liquid solution of a petroleum fluid can occur when it is subjected to low temperatures. The solid phase - formed by high molecular wheight components - may cause serious operational problems that can even lead to an interruption of the mixture production. Hence, it is important to predict the way it hap
Publicado em: 1994
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11. Is the bithiazole moiety of bleomycin a classical intercalator?
Bleomycin is a widespread anticancerous drug, the biological activity of which having been extensively studied. Its metal ion-chelating portion has been shown to cleave DNA whereas the role of the bithiazole moiety is still questionable. In order to elucidate this problem some 2', 4-disubstituted bithiazoles structurally related to the "tripeptide S" moiety
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12. Interaction of DNA with a porphyrin ligand: evidence for intercalation.
The porphyrin photosensitizer, meso-Tetra (4-N-methylpyridyl) porphine tetraperchlorate binds to calf thymus DNA by intercalation and by external electrostatic association. This was concluded from the results of measruements involving Scatchard analysis, viscometry, thermal denaturation, and circular dichroism.