Diffusional Effects
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Effect of an Organo-Modified Montmorillonite on the Barrier Properties of PET Nanocomposites Using a Polyester Ionomer as a Compatibilizing Agent
Poly(ethylene terephthalate)/organically modified montmorillonite (PET/o-Mt) nanocomposites were prepared via melt intercalation in a twin-screw extruder using a polyester ionomer (PETi) as compatibilizer. The o-Mt content used was 0, 1, 3 or 5 wt% and the compatibilizer/o-Mt mass ratio was 0/1, 1/1 or 3/1. The main objective was to study the effects of the
Mat. Res.. Publicado em: 09/05/2017
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2. Ultrasound effects on the mass transfer processes during drying kinetic of olive leaves (Olea Europea, var. Serrana).
The large amount of materials derived from olive trees pruning may constitute a source of compounds with antioxidant activity. The air drying of raw matter is a previous stage before extraction preserving the raw matter and avoiding the interference of water on the process but it constitutes a slow and high energy demanding process. In this sense, the applic
Defect and Diffusion Forum. Publicado em: 2011
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3. Correlação entre parâmetros da cinética de intumescimento com características estruturais e hidrofílicas de hidrogéis de poliacrilamida e metilcelulose
In this paper, the effects of acrylamide (AAm), methylcellulose (MC) contents, pH and ionic strength on kinetic, network and hydrophilic properties of polyacrylamide and methylcellulose hydrogels were investigated. The hydrogels were characterized by evaluating of network [average molecular weight between crosslinks (M C), crosslink density (q) and the numbe
Química Nova. Publicado em: 2009
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4. Avaliação da secagem do bagaço de cajá usando planejamento fatorial composto central
This work deals with the kinetics assay of Cajá (Spondias mombin L.) bagasse drying by an experimental design using a tray dryer. In order to add-value to this product a kinetic study has been carried out. A central composite experimental design has been carried out to evaluate the influence of the operational variables: input air temperature (55; 65 e 75C)
Publicado em: 2008
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5. Desenvolvimento de um modelo matematico mais rigoroso para polimerização radicalar controlada mediada por radicais nitroxido de estireno / Development of more detailed mathematics model for nitroxide mediated living free radical polymerization (NMRP)
Living Free-Radical Polymerization (LFRP) has been target of much attention in the last years, because it allows getting polymers with a highly controlled microstructure, with narrow distribution of the average molecular weights and polydispersity (PDI) close to unit, and with complex molecular structures (e.g. pure block copolymers), with different architec
Publicado em: 2007
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6. Aplicação da ressonancia de plasmon de superficie e da microbalança de cristal de quartzo na investigação de processos interfaciais visando o desenvolvimento de sensores / Applications of surface plasmon resonance and quartz crystal microbalance in the investigation of interface processes intending the sensors development
The present work describes the applications of surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) in the investigation of interface processes in the attempt to improve the understanding and application of the investigated systems as well as the establishment of the applications of the SPR allied with electrochemical techniques. In this sen
Publicado em: 2006
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7. Determination of the enzyme reaction rate in a differential fixed-bed reactor: a case study
The reaction rate of starch hydrolysis catalyzed by a glucoamylase covalently bound to chitin particles was measured in a Differential Fixed-Bed Reactor (DFBR). Under selected test conditions the initial reaction rate may represent biocatalyst activity. Some aspects which influence measurement of the initial reaction rate of an immobilized enzyme were studie
Brazilian Journal of Chemical Engineering. Publicado em: 2001-03
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8. Extração de oleo essencial de cravo-da-india em leito fixo com dioxido de carbono liquido suberitico
The extraction of clove oil with sub critical carbon dioxide (liquefied carbon dioxide at. pressures just below 72.3 kgf/cm2 and temperatures below 31.8°C) was studied. Apparatus was set up to operate with carbon dioxide at two different pressures (66 and 70 kgf/cm gauge ) and variable temperature. Grinde clove buds were packed into a fixed bed extractor (3
Publicado em: 1989
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9. Estudo cinetico da invertase livre e imobilizada em alginato de calcio
In this work special emphasis was given to the study of the kinetics of sucrose hydrolysis by invertase. The enzyme was used in free as well immobilized in calcium alginate forms. The kinetic parameters ware determined considering the initial rates of reaction, in order to avoid the iinhibition phenomena caused by the products glucose and fructose. The pH an
Publicado em: 1989
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10. Electrostatic and hydrodynamic orientational steering effects in enzyme-substrate association.
Diffusional encounters between a dumbbell model of a cleft enzyme and a dumbbell model of an elongated ligand are simulated by Brownian dynamics. The simulations take into account electrostatic and hydrodynamic interactions between the molecules. It is shown that the primary effect of inclusion of hydrodynamic interactions into the simulation is an overall d
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11. Hydrodynamic steering effects in protein association.
Protein-ligand reaction rates are often limited by the rate of diffusional encounter of the protein and ligand in solution. Reaction rates, however, can be much greater than expected, given the necessity for correct orientation before reaction. A number of forces can affect the orientation of the protein and ligand in solution, and thus increase the reaction
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12. A bioresorbable, polylactide reservoir for diffusional and osmotically controlled drug delivery
The purpose of this study was to design and characterize a zero-order bioresorbable reservoir delivery system (BRDS) for diffusional or osmotically controlled delivery of model drugs including macromolecules. The BRDS was manufactured by casting hollow cylindrical poly (lactic acid) (PLA): polyethylene glycol (PEG) membranes (10×1.6 mm) on a stainless steel
Springer-Verlag.