Effect of Temperature on the Rheological Behaviour, Slip Casting Rate and Densification of Calcium Hydroxyapatite Slurry

The purpose of this study is to investigate the rheological properties of sumac extract in different concentrations at different temperatures as well as its flow behavior in sudden expansion-contraction and at 90o elbow with CFD. The rheological behaviour of sumac extract in different concentrations (45.65%, 50.44%, 55.53%, 60.32%, and 65.13% total solids) were evaluated using a rotational viscometer at different temperatures (10, 20, 30, 40 and 50 C). Sumac extract samples showed Newtonian flow properties in these temperature ranges. Arrhenius equation was used to determine the effect of temperature. Ea value varied in the range of 11.16-34.35 kJ/mol, which diminished with a decrease in concentration. Power and Exponential models were used to characterize the effect of concentration on flow behavior. Time average velocity vector and contours, vorticity contours, kinetic energy contours, and pressure contours are given to show the flow behavior of sumac extract.

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Simple Rheological Tests and Protocols for SME Ceramic Producers

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.68.65 ◽

2010 ◽

Vol 68 ◽

pp. 65-74 ◽

Cited By ~ 1

Author(s):

Davide Gardini ◽

Carmen Galassi

Keyword(s):

Flow Behavior ◽

Slip Casting ◽

Rheological Behaviour ◽

Critical Issue ◽

Thixotropic Behavior ◽

History Of ◽

Control Procedures ◽

Jet Printing ◽

Ceramic Suspensions ◽

Printing Ink

The rheological behaviour of ceramic suspensions affects the quality of the products and the yield of the processes. Therefore, rheology control is needed to obtain materials with enhanced properties and to reduce energy consumption. The importance of rheology control in slip casting, spray-drying, screen-printing, ink-jet printing, glazing, and so on, either for Quality Control (QC) aims or for system formulation, has been acknowledged from many years. As in these control procedures the determination of the rheological behavior is a critical issue, this work is focused on the assessment of viscosity (flow behavior) and its dependency on time (usually, thixotropic behavior). Most of ceramic factories still use simple and cheap instruments to investigate rheological behaviors (or something related to it). However, the information provided by such instruments is not completely satisfactory. Therefore, optimization of the procedures is important to improve reproducibility and precision. Suggestions about simple tests and protocols applicable to viscometers ordinarily available in ceramic factories are given. Protocols consider besides a precise description of the tests, all other factors that can affect the results, such as the thermo-mechanical history of the samples before testing.

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Modelling of Rheological Behaviour of Pulps and Purées from Fresh and Frozen-Thawed Murta (Ugni molinae Turcz) Berries

International Journal of Food Engineering ◽

10.1515/1556-3758.2738 ◽

2012 ◽

Vol 8 (3) ◽

Cited By ~ 3

Author(s):

Kong S. Ah-Hen ◽

Antonio Vega-Gálvez ◽

Nelson O. Moraga ◽

Roberto Lemus-Mondaca

Keyword(s):

Experimental Data ◽

Activation Energy ◽

Rapid Change ◽

Correlation Coefficients ◽

Rheological Behaviour ◽

Type Equation ◽

Effect Of Temperature ◽

Rheological Models ◽

Temperature Activation ◽

Ugni Molinae

Abstract The rheological behaviour of purées and pulps from fresh and frozen-thawed murta (Ugni molinae Turcz) berries was studied at 30, 45, 60 and 75 °C. The Mitschka method was shown to be applicable to the murta berries, with its products showing non-Newtonian pseudoplastic behaviour. Rheological models as Ostwald-de Waele, Herschel-Bulkley, Bingham, Casson and Mizrahi-Berk fitted the experimental data with high values for correlation coefficients. Effect of temperature was evaluated using an Arrhenius-type equation. Compared to the murta pulp, the fresh or frozen-thawed murta purées had higher apparent viscosity at any shear rate and would undergo a more rapid change in viscosity with temperature. Activation energy for fresh and frozen-thawed purées were 22.335 kJ mol-1 (R2 = 0.9225), and 16.478 kJ mol-1 (R2 = 0.9654) respectively, while for fresh and frozen-thawed pulp Ea values of 8.967 kJ mol-1 (R2 = 0.9618) and 6.943 kJ mol-1 (R2 = 0.9773) were determined respectively.

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Rheological behaviour of enzyme clarified Indian gooseberry juice

International Agrophysics ◽

10.2478/v10247-012-0021-y ◽

2012 ◽

Vol 26 (2) ◽

pp. 145-151 ◽

Cited By ~ 3

Author(s):

S. Manjuantha ◽

P. Raju ◽

A. Bawa

Keyword(s):

Activation Energy ◽

Shear Rate ◽

Viscous Flow ◽

Rheological Behaviour ◽

Soluble Solids ◽

Effect Of Temperature ◽

Exponential Equation ◽

Indian Gooseberry ◽

Solids Concentration ◽

Soluble Solids Concentration

Rheological behaviour of enzyme clarified Indian gooseberry juiceThe rheological behaviour of enzyme clarified depectinated Indian gooseberry juice and its concentrate was studied as a function of total soluble solids concentration in the range of 8.2 to 35.9°Bx and temperatures from 20 to 80°C using coaxial controlled stress rheometer up to a shear rate of 600 s-1. The results indicated that the enzyme clarified gooseberry juice behaves like a Newtonian fluid with a viscosity ranging from 3.92 to 7.94 mPa s. The effect of temperature on viscosity of different concentration of juice was described by an Arrhenius type relationship (R >0.99). The activation energy for viscous flow was found to be in the range 4.34 to 5.37 KJ mol-1depending upon the concentration of the juice. The activation energy of viscous flow on concentration was modeled by exponential equation (R>0.99). The effect of concentration on viscosity followed an exponential type relationship (R>0.98) at the temperature used.

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EFFECT OF TEMPERATURE ON RHEOLOGY BEHAVIOUR OF BANANA PEEL PECTIN EXTRACTED USING HOT COMPRESSED WATER

Jurnal Teknologi ◽

10.11113/jt.v80.11467 ◽

2018 ◽

Vol 80 (3) ◽

Author(s):

Noor Azwani Mohd Rasidek ◽

Mariam Firdhaus Mad Nordin ◽

Yus Aniza Yusoff ◽

Hideaki Tokuyama ◽

Yuichiro Nagatsu

Keyword(s):

Particle Size ◽

Regression Analysis ◽

Rheological Behaviour ◽

Total Sugar ◽

Effect Of Temperature ◽

Banana Peel ◽

Model Flow ◽

Similar Range ◽

Flow Deformation ◽

Hot Compressed Water

Banana peel pectin is extracted from banana peel waste using a hot compressed water extraction (140-160°C, 5 minutes, 1.18 mm particle size). Physicochemical contents of banana peel pectin were found to be in a similar range with commercial pectin, and is comprised of moisture (7.44-8.47%), ash (3.45-4.98%), protein (1.08-1.92%), fat (0.04-3.42), carbohydrate (83-86%), total sugar (1.77-3.41%), energy (353-369 kcal/100g) and specific heat (1.42-1.62 kJ/kg°C). These contents possibly related to their flow deformation of rheological behaviour. Regression analysis displayed good agreements in all models applied, apart from the Casson Model. Flow behaviour indices, n<1 and decreasing of apparent viscosity within increasing of shear rate indicates that banana peel pectin has excellent shear thinning behaviour with a presence of yield stress.

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