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Carboxymethyl lignin as stabilizing agent in aqueous ceramic suspensions

Cerrutti, B. M.; de Souza, C. S.; Castellan, A.; Ruggiero, R.; Frollini, Elisabete
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
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Identifying new uses for residues of industries that process large quantities of biomass, as in bioethanol production, is essential for a sustainable development with reduced impact on the environment, which is the reason why many efforts have been devoted to find noble uses for lignins. in this study, a lignin obtained from sugarcane bagasse in a bioethanol producing plant was carboxymethylated to yield the water-soluble carboxymethyl lignin (CML), which was then used as stabilizing agent in aqueous alumina (Al2O3) suspensions. CML had a degree of substitution 0.46 +/- 0.01, in relation to the C9 unit of lignin, and behaved as a polyelectrolyte in a large pH range owing to the dissociation of carboxylic groups. The action of CML as stabilizing agent of alumina aqueous suspensions was investigated using viscometry, zeta potential, and photon correlation spectroscopy (PCS) measurements, mainly as a function of pH and time. Overall, the results showed that CML had a good performance as a deflocculating agent, because it led to dispersions with low viscosity and small change in particle size as a function of time. The positive effect from the addition of CML was confirmed in the morphological features of the material obtained from the alumina suspensions after elimination of water...

Preparação e estabilização de uma suspensão cerâmica de porcelana de ossos.; Preparation and stabilization for ceramics suspensions of bone porcelain.

Vera Alatrista, Gerardo Augusto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 31/07/2008 PT
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O estudo da dispersão e estabilização de barbotinas de porcelana de cinza de ossos é uma etapa muito importante no processo de conformação de peças cerâmicas, assim como também a etapa de obtenção da sua principal matéria-prima que é a cinza de ossos, devido a que constitui 50% em peso da porcelana e por ser uma matéria-prima renovável, reciclável e com alto valor agregado na fabricação de porcelana. Neste trabalho se investigou a influência das temperaturas de calcinação dos ossos (700, 800, 900 e 1000 °C) moídos e lavados, no seu tamanho, forma das partículas, composição química, comportamento elétrico superficial das partículas com o meio líquido, grupos funcionais e possíveis contaminantes nas superfícies das partículas dos ossos calcinados, que poderiam prejudicar a preparação de barbotinas de porcelana de ossos. Mostra-se também a dispersão, preparação e a estabilização da mistura de porcelana de ossos (50% cinza de ossos, 25% de caulim, 25% de feldspato) por meio dos ensaios de viscosidade e mobilidade eletroforética, conseguindo dispersar, homogeneizar e estabilizar as suspensões de porcelana de ossos aplicando tempos de envelhecimentos apropriados.; The study of the dispersion and stabilization of slip casting of bone porcelain is a very important stage in the process of preparation of suspensions ceramic...

"Estabilização de suspensões aquosas de alumina pela adição de taninos e quitosana quaternizada"; Stabilization of aqueous alumina suspensions by addition of tannin and quaternized chitosan

Cerrutti, Bianca Machado
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/09/2005 PT
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A indústria cerâmica tem destinado produtos para as mais diversas áreas e, com a crescente exigência de alta qualidade, tornou-se necessário desenvolver novas técnicas para o processamento cerâmico. O objetivo consiste em produzir corpos a verde (antes da queima) mais homogêneos, com menor incidência de micro-defeitos. Tais materiais podem ser produzidos preparando-se suspensões aquosas de pós cerâmicos como o óxido de alumínio (Al2O3), conhecido como alumina. Estas suspensões possuem um alto teor de sólidos no meio. A adição de outras espécies ao meio auxilia a dispersão das partículas, aumentando a estabilidade da suspensão. Estas espécies podem ser polieletrólitos (polímeros com cargas) que interagem com a superfície das partículas de alumina, através de vários mecanismos, promovendo um impedimento à aproximação de outras partículas. Neste trabalho, foram utilizados três tipos de taninos, que são macromoléculas de origem vegetal, de nome comercial Weibull e Macrospec; e Dispersan, sendo que a diferença entre eles está na quantidade de grupos hidroxila, maior em Macrospec com relação a Weibull, e na mistura com polímero sintético, o poliacrilato de sódio, caso do Dispersan. Um derivado quaternizado de quitosana...

Biomacromoléculas carboximetiladas: atuação como agentes de estabilização de suspensões aquosas de alumina; Carboxymethylated biomacromolecules: used as stabilizing agents for aqueous alumina suspensions

Cerrutti, Bianca Machado
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/08/2010 PT
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A estabilização de suspensões de alumina é essencial para a fabricação de vários produtos, especialmente na indústria cerâmica e com o controle das propriedades que se pode atingir usando polímeros como agentes estabilizantes. Na busca de processos industriais que preservem o meio ambiente, polímeros sintéticos podem ser substituídos por biopolímeros, com a vantagem adicional de encontrar usos nobres para rejeitos, como quitina, da qual se obtêm a quitosana e ligninas. Nesta tese, os derivados carboximetilados de celulose, a carboximetilcelulose (CMC) e quitosana, a carboximetilquitosana (CMQ) foram preparados e caracterizados por Espectroscopia de Ressonância Magnética Nuclear de Próton (1HRMN), Espectroscopia na Região do Infravermelho (FTIR), Termogravimetria (TG), Calorimetria Diferencial Exploratória (DSC), Difração de raios X, Cromatografia de Exclusão por Tamanho (SEC). O derivado obtido da lignina, a carboximetil-lignina, (CML) foi caracterizado por Espectroscopia na Região do Infravermelho (FTIR), Termogravimetria (TG), Calorimetria Diferencial Exploratória (DSC). Os três derivados obtidos foram usados como agentes estabilizantes para suspensões aquosas de alumina. A reação de carboximetilação ocorreu em meio heterogêneo...

Influence of viscoelastic characteristics of the colloidal suspensions on the formation of SnO2 supported membranes

Santos, L. R B; Larbot, A.; Santilli, C. V.; Pulcinelli, S. H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1738-1741
ENG
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SnO2 supported membranes have been prepared by sol-casting on alumina tubular substrate, using aqueous colloidal suspensions prepared by sol-gel route. The viscoelastic behaviour during sol ageing was analyzed by dinamic rheologial measurements. The complex viscosity and the storage and loss moduli have been followed during the sol-gel transition and the results have been correlated with the linear aggregates growth and the scalar percolation models. The scanning electron microscopy has evidenced that the homogeneity and thickness of the membrane depend on the sol ageing time. Crack-free and homogeneous membranes have been obtained for coated layers of 0.5μm thickness. © 1997 Trans Tech Publications.

Reologia de suspensões-modelo : efeito da concentração de solidos e da matriz dispersante; Model-suspensions rheology : effect of solids concentration and matrix characteristics

Ana Carla Kawazoe Sato
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/06/2009 PT
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A influência das características físicas e químicas do meio dispersante sobre a reologia de suspensões-modelo foi avaliada visando o entendimento do comportamento de sistemas reais como as polpas de frutas. Para isto, o trabalho foi dividido em duas etapas: 1) estudo do efeito da composição de sistemas-modelo de soro de polpas de frutas no comportamento reológico, e 2) estudo de suspensões-modelo de diferentes partículas dispersas em matrizes com diferentes propriedades físicas e químicas. Na primeira etapa, foi verificado o efeito da presença de pectinas de alto e baixo grau de metoxilação, assim como de suas misturas. Os resultados mostraram um efeito sinergístico da mistura destes diferentes tipos de pectinas, devido à maior viscosidade e pseudoplasticidade dos sistemas mistos quando comparados aos sistemas com um único tipo de pectina. Assim, ressaltou-se a importância dos diferentes tipos de ligação no comportamento reológico destes sistemas. A segunda etapa permitiu a compreensão das interações entre partículas e partícula-solvente e a sua influência no comportamento reológico de suspensões-modelo. De um modo geral, as interações entre partículas e partícula-solvente foram maiores nos meios menos viscosos e polares. Tais resultados foram refletidos pelo valor ajustado da fração máxima de empacotamento (fm) por diferentes modelos...

The deflocculation of kaolin suspensions : the effect of various electrolytes

Penkavová, V.; Guerreiro, Margarida; Tihon, J.; Teixeira, J. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 14/10/2013 ENG
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The deflocculation effect of conventional additives to kaolin suspensions is evaluated from the results standard rheological measurements. Several widely used electrolytes (NaOH, Na2C03, Na2Si03, SHMP = sodium hexametaphosphate, and CMC = sodium salts of carboxymethylcellulose) have been tested. The optimal concentrations of these deffloculants, in respect to reaching the maximum reduction of initial suspension viscosity, are found. The stability of deflocculated kaolin suspensions against sedimentation is evaluated and different aspects of the observed flow enhancement discussed. Inorganic electrolytes are found to be more effective in viscosity reduction, but on the other hand, low-molecular organic CMC additives produce more stable final suspensions.; Czech Science Foundation GACR through the contract P101/12/0585

Fluid Flow and Solid/Fluid Suspensions Flow in 3-D Packed Beds of Spheres: the effect of periodicity of fixed beds

Serrenho, Ana; Miguel, Antonio F
Fonte: TRANS. TECH. PUBLICATIONS, Switzerland, UK, USA Publicador: TRANS. TECH. PUBLICATIONS, Switzerland, UK, USA
Tipo: Artigo de Revista Científica
ENG
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A 3-D numerical study is performed to investigate the effects of periodicity (geometry) on flow of fluid and on flow of solid/fluid suspensions in packing arrangements of fixed beds of spheres. The porosity is fixed at 0.58 and the following packing arrangements are studied: simple cubic, face-centered cubic, hexagonal, rhomboedric hexagonal and tetragonal. Simulations are carried out at Reynolds numbers ranging from 0.1 and 50, and using solid suspensions with different sizes (0.2, 2 and 10 micron) and densities (200 and 2000 kg/m3). The effect of the periodicity on fluid flow characteristics (permeability and inertia parameter) and on the penetration efficiency of solid suspensions within the packed beds is analyzed and quantified.

Voluntary Trading Suspensions and Media Coverage on the LSE

Brailsford, Tim; Cross, Tony; Hodgson, Allan
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Working/Technical Paper Formato: 264974 bytes; application/pdf
EN_AU
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The study examines voluntary suspensions and subsequent relistings on the London Stock Exchange. The results show that voluntary suspensions produce an abnormal return series very similar in pattern to the exchange-initiated suspensions observed elsewhere. The paper then examines the role of media coverage on price movements around the suspension. In the pre-suspension period the quantity of news is positively associated with abnormal returns. Subsequent to relisting, the impact of media coverage switches from a quantitative role to a more qualitative informative role. Other evidence shows that firms associated with takeover activity have lower volatility of returns around the suspension consistent with a convergence of beliefs, that the length of the suspension period is not significant, and media coverage does not increase the heterogeneity of investor beliefs. Overall the results suggest incremental media information may have a significant accociation with price movements.; no

Yield stress measurements in suspensions: an inter-laboratory study

Nguyen, Q.; Akroyd, T.; De Kee, D.; Zhu, L.
Fonte: Korean Society of Rheology Publicador: Korean Society of Rheology
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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The first international inter-laboratory study, involving six laboratories, has been conducted to examine issues associated with yield stress measurements in suspensions. The initial focus of the project was to evaluate the reliability and reproducibility of several common yield stress measuring techniques employed in different laboratories and with different instruments. Aqueous suspensions of colloidal TiO2 at concentrations of 40-70 wt% solids were used as the test fluids. A wide range of instruments and techniques employing both direct and indirect methods were used to determine the yield stress of the samples prepared according to a prescribed procedure. The results obtained indicated that although variations of results existed among different techniques, direct yield stress measurements using static methods produced more reliable and repeatable results than other methods. Variability of the yield stress measured using different techniques within any laboratory however was less significant than variability of the results among different laboratories. The nature and condition of the test suspensions was identified as the most likely factor responsible for the poor reproducibility of yield stress measurements from different laboratories.; © 2006 by The Korean Society of Rheology

Electroacoustic characterization of bidisperse suspensions

Jim??nez Olivares, Mar??a Luisa; Arroyo Rold??n, Francisco J.; Ahualli, Silvia; Rica Alarc??n, Ra??l; Delgado, ??ngel V.
Fonte: Croatian Chemical Society Publicador: Croatian Chemical Society
Tipo: Artigo de Revista Científica
ENG
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Electroacoustic techniques are promising tools for the size determination and electrokinetic characterization of concentrated colloidal suspensions. When particles are not homogeneous in size and/or density, the dynamic mobility obtained is a kind of average of the mobilities of every particle. In this paper, we try to discern which averaging procedure provides a better description of the dynamic mobility of bidisperse suspensions consisting of a mixture of two very different types of particles. The results show that the amplitude of the sound wave induced by an applied ac field (electrokinetic sonic amplitude) is not just the sum of the amplitudes of the waves generated by every particle but has a larger contribution from the larger particles, although the small size entities considerably influence the behaviour of the latter because of their interference in the fluxes of the fluid and ions around them.

General electrokinetic model for concentrated suspensions in aqueous electrolyte solutions: electrophoretic mobility and electrical conductivity in static electric fields

Carrique Fern??ndez, F??lix; Ruiz-Reina, Emilio; Roa, Rafael; Arroyo Rold??n, Francisco J.; Delgado, ??ngel V.
Fonte: Elsevier Publicador: Elsevier
Tipo: Pré-impressão
ENG
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In recent years different electrokinetic cell models for concentrated colloidal suspensions in aqueous electrolyte solutions have been developed. They share some of its premises with the standard electrokinetic model for dilute colloidal suspensions, in particular, neglecting both the specific role of the so-called added counterions (i.e., those released by the particles to the solution as they get charged), and the realistic chemistry of the aqueous solution on such electrokinetic phenomena as electrophoresis and electrical conductivity. These assumptions, while having been accepted for dilute conditions (volume fractions of solids well below 1 %, say), are now questioned when dealing with concentrated suspensions. In this work, we present a general electrokinetic cell model for such kind of systems, including the mentioned effects, and we also carry out a comparative study with the standard treatment (the standard solution only contains the ions that one purposely adds, without ionic contributions from particle charging or water chemistry). We also consider an intermediate model that neglects the realistic aqueous chemistry of the solution but accounts for the correct contribution of the added counterions. The results show the limits of applicability of the classical assumptions and allow one to better understand the relative role of the added counterions and ions stemming from the electrolyte in a realistic aqueous solution...

On the theory of magnetoviscous effect in magnetorheological suspensions

Zubarev, Andrey; Iskakova, Larisa; L??pez-L??pez, Modesto T.; Kuzhir, Pavel; Bossis, Georges
Fonte: Society of Rheology Publicador: Society of Rheology
Tipo: Artigo de Revista Científica
ENG
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Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.; The following article appeared in Zubarev, A.; et al. On the theory of magnetoviscous effect in magnetorheological suspensions. Journal of Rheology, 58: 1673 (2014) and may be found at http://dx.doi.org/10.1122/1.4889902; A theoretical model of magnetoviscous effect in a suspension of nonBrownian linearly magnetizable particles is suggested. A simple shear flow in the presence of an external magnetic field aligned with the velocity gradient is considered. Under the action of the applied field, the particles are supposed to form dense highly elongated droplike aggregates. Two different scenarios of the aggregates??? destruction under shearing forces are considered, namely, a ???bulk??? destruction of aggregates into pieces and an ???erosive??? destruction connected to the rupture of individual particles from the aggregate surface. Both models are based on a balance of forces acting either on the whole aggregate or on individual particles. The two approaches lead to qualitatively different Mason number (Ma) behaviors of the magnetic suspensions: The suspension viscosity scales as either Ma^-2/3 for the bulk destruction of aggregates or Ma^-4/5 for the erosive destruction. In any case...

Deterministic solution of the kinetic theory model of colloidal suspensions of structureless particles

MAÎTREJEAN, Guillaume; AMMAR, Amine; CHINESTA, Francisco; GRMELA, Miroslav
Fonte: Springer Publicador: Springer
EN_US
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A direct modeling of colloidal suspensions consists of calculating trajectories of all suspended objects. Due to the large time computing and the large cost involved in such calculations, we consider in this paper another route. Colloidal suspensions are described on a mesoscopic level by a distribution function whose time evolution is governed by a Fokker–Plancklike equation. The difficulty encountered on this route is the high dimensionality of the space in which the distribution function is defined. A novel strategy is used to solve numerically the Fokker–Planck equation circumventing the curse of dimensionality issue. Rheological and morphological predictions of the model that includes both direct and hydrodynamic interactions are presented in different flows.

Suspensões magneto-reologicas de pos de ferro carbonilo : um estudo da influencia das propriedades magneticas e do tamanho das paritculas; Magneto-rheological suspensions: a study of the influence of the magnetic properties and particle size of carbonyl iron powder

Antonio Jose Faria Bombard
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/04/2005 PT
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O tamanho, distribuição de tamanhos de partículas e a susceptibilidade magnética de alguns pós de ferro carbonilo comerciais (BASF AG CC, CS, HQ, OX e SM) foram medidas. O tamanho das partículas aumenta na seguinte ordem: HQ < SM < CC ~ OX < CS. A susceptibilidade magnética aumenta na ordem: HQ ~ OX << SM ~ CC ~ CS. Suspensões magneto-reológicas (SMR) com 66% massa/massa de pó de ferro foram preparadas e suas propriedades reológicas foram avaliadas na ausência de campo magnético, e sob campos de 100, 200 e 300 Oersted. A tensão de escoamento sob 300 Oe, medida através da deformação causada na amostra por uma rampa controlada de tensão de cisalhamento, aumentou na ordem: HQ ~ OX < SM < CC < CS, indicando uma correlação direta com a susceptibilidade magnética. A viscosidade plástica sem campo magnético aumentou na ordem: CS < CC < OX < SM < HQ, uma correlação inversa com o tamanho das partículas. Estes resultados preliminares mostram que o tamanho e ou a distribuição de tamanhos de partículas pode ser outra importante propriedade dos pós, juntamente com a susceptibilidade magnética, na formulação otimizada de SMR. Em um outro estudo, SMR baseadas também em pós de ferro carbonilo (BASF AG CL, HQ, OX e SM) e dois tipos de sílicas pirogênicas (Cab-O-Sil M5 - hidrofilica...

Effect of solid loading and aggregate size on the rheological behavior of PDMS/Calcium Carbonate suspensions

Behzadfar,E.; Abdolrasouli,M. H.; Sharif,F.; Nazockdast,H.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
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The purpose of this study is to examine the effect of solid loading and aggregate size on the rheological behavior of PDMS (polydimethylsiloxane)/CC (calcium carbonate) suspensions. Mixtures containing 10 to 40 vol% of CC were prepared; the effect of shear rate and particle content on aggregate size and rheological properties was studied. Rheological properties including viscosity, loss modulus, storage modulus and yield stress were measured using rotational and oscillatory rheometry. Casson's equation was found to satisfactorily model the samples' stress response as a function of shear rate for different solid content. While solid content did not have any effect on the aggregate size, shear rate did influence the aggregate median diameter. It was observed that suspensions with higher aggregate size had a higher viscosity. In general, for a given volume fraction, a small change in the aggregate size had a significant impact on the viscosity, particularly at low shear rates.

Why pH titration in lysozyme suspensions follow a Hofmeister series

Bostrom, Mathias Anders; Ninham, Barry
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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We present theoretical results that provide new insights into the Hofmeister effects observed in protein suspensions. With a buffered solution at a supposedly fixed pH, measurements of that pH with glass electrodes in protein suspensions depend strongly o

Quality control of liquid pigment-based suspensions using ultrasounds

Sierra Sánchez, Carlos José; Resa López, Pablo Ismael; Elvira Segura, Luis
Fonte: Sociedad Española de Acústica Publicador: Sociedad Española de Acústica
Tipo: Comunicación de congreso Formato: 396370 bytes; application/pdf
ENG
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Ponencia presentada en el XIX Congreso Internacional de Acústica (ICA2007), Madrid, 2-7 Sep 2007.-- PACS: 43.35.Bf.; The determination of particle size in suspensions is a relevant issue in many industrial applications, for which this size represent a quality parameter of primary importance. The use of particle size ultrasonic measuring systems is becoming widespread especially in those applications dealing with concentrate suspensions, where optic methods are less efficient. In this work, the analysis of amplitude and time of flight variations by means of pulse-echo a through-transmission techniques of different size and nature pigments and solvents is presented. Different frequencies and temperatures were used to detect variations of ultrasonic wave propagation characteristics in the suspensions. The preliminary results presented here show the viability of using the measurement of amplitude and time of flight to asses the quality of suspensions and therefore, to develop noninvasive and non-destructive methods to control the pigment production.; This work was done with funding obtained from the CSIC by means of the project 200550F0190 during the joining of a pre Ph-D fellowship I3P financed by the Social European Fund.; Peer reviewed

Magnetic Manipulation and Assembly of Multi-component Particle Suspensions

Erb, Randall Morgan
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 6383465 bytes; application/pdf
Publicado em //2009 EN_US
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This thesis will investigate previously unexplored concepts in magnetic manipulation including controlling the assembly of magnetic and nonmagnetic particles either in bulk fluid or near a substrate. Both uniform glass interfaces and substrates with magnetic microstructures are considered. The main goal of this work is to discuss new strategies for implementing magnetic assembly systems that are capable of exquisitely controlling the positions and orientations of single-component as well as multi-component particle suspensions, including both magnetic and non-magnetic particles. This work primarily focuses on controlling spherical particles; however, there are also several demonstrations of controlling anisotropically shaped particles, such as microrods and Janus colloids.

Throughout this work, both conventional magnetophoresis and inverse magnetophoresis techniques were employed, the latter relying on ferrofluid, i.e. a suspension of magnetic nanoparticles in a nonmagnetic carrier fluid, which provides a strong magnetic permeability in the surrounding fluid in order to manipulate effectively non-magnetic materials. In each system it was found that the dimensionless ratio between magnetic energy and thermal energy could be successfully used to describe the degree of control over the positions and orientations of the particles. One general conclusion drawn from this work is that the ferrofluid can be modeled with a bulk effective permeability for length scales on the order of 100 nm. This greatly reduces modeling requirements since ferrofluid is a complex collection of discrete nanoparticles...

The Viscosity of Aqueous Suspensions of Cellulose Fibres: Part 2. Influence of Temperature and Mix Fibres

Ferreira,Abel G.M.; Silveira,Maria Teresa; Lobo,Lélio Q.
Fonte: Unidade de Silvicultura e Produtos Florestais Publicador: Unidade de Silvicultura e Produtos Florestais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2003 EN
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Measurements were made of the viscosity of aqueous fibre suspensions of bleached kraft pulps from eucalyptus and pine trees over the temperature range 15 to 75ºC and consistencies from 0.20 to 1.00 mass per cent. In addition, the viscosity of mixed aqueous suspensions of eucalyptus and pine cellulose fibres was measured at 25ºC, varying the mass fraction of short fibres (from eucalyptus) and long fibres (from pine) from 0.25 to 0.75 for consistencies ranging from 0.05 to 0.70 per cent. The viscosities of the mixed suspensions can be shown to be the mass average of the viscosities of the aqueous suspensions of the two species. Correlations describing the dependency of viscosity on temperature and on consistency were established for both species.