Effect of Temperature on the Flow Properties of Drilling Fluids

1967 ◽  
Author(s):  
L.E. Bartlett
Author(s):  
Se-Ra Hong ◽  
Dong-Soo Sun ◽  
Whachun Yoo ◽  
Byoungseung Yoo

Gum-based food thickeners are widely used to care for patients with dysphagia in Korea. In this study, the flow properties of commercially available gum-based food thickeners marketed in Korea were determined as a function of temperature. The flow properties of thickeners were determined based on the rheological parameters of the power law and Casson models. Changes in shear stress with the rate of shear (1-100 s-1) at different temperatures (5, 20, 35, and 50 oC) were independent of the type of thickener. All thickeners had high shear-thinning behavior (n=0.08-0.18) with yield stress at the different temperatures tested. In general, apparent viscosity (na,50) values progressively decreased with an increase in temperature. In addition, the consistency index (K) and Casson yield stress (σoc) values did not change much upon an increase in temperature from 5 to 35 oC, except for sample B. In the temperature range of 5-50 oC, the thickeners followed an Arrhenius temperature relationship with a high determination coefficient (R2=0.93-0.97): activation energies (Ea) for the flow of thickeners were in the range of 2.44 - 10.7 kJ/mol. Rheological parameters demonstrated considerable differences in flow behavior between the different gum-based food thickeners, indicating that their flow properties are related to the type of thickener and the flow properties of gum.


Author(s):  
Zurriye Yilmaz ◽  
Mehmet Dogan ◽  
Mahir Alkan ◽  
Serap Dogan

In the food industry, rheological properties, such as viscosity, shear rate, and shear stress, are the most important parameters required in the design of a technological process. Therefore, in this study, we determined the flow behavior and the time-dependent flow properties of Turkish Delight (TD) in the temperature range of 25-75°C using a capillar rheometer. The structure and thermal properties of TD were investigated by XRD and a simultaneous DTA/TG analysis. The shear rate values ranged from 5 to 300s-1. We found that: (i) TD behaved as non- Newtonian pseudoplastic foodstuff; (ii) while the measurement temperature increased, viscosity decreased; and (iii) TD was a rheopectic material. The effect of temperature on viscosity was described by means of the Arrhenius equation. The activation energies for the flow of pseudoplastic TD varied from 50.1-74.2 kJ/mol, depending on shear rate. Three models were used to predict the flow behavior of TD, namely, the Power law, Bingham and Casson models. The Power law model adequately described well the flow behavior of TD at different temperatures.


2013 ◽  
Vol 829 ◽  
pp. 818-824
Author(s):  
Sahar Kafashi ◽  
Ramin Taghdimi ◽  
Gholamreza Karimi

This study was aimed to investigate the rheological properties and the possibility of nano(Na, Ca )- bentonites nanoproducts to meet the required drilling mud properties. Sepiolite (Sp) and the mixture of 2% nanoNaB with 1% Sp were collected and prepared from Irans oil Company (NIOC). The nanoclay performance evaluation involved the experimental tests of the rheological properties, filtration and gel strength. According to the results obtained from flow properties tests for the mixture, it was indicated that the mixture was not adequate to be a suitable drilling fluid. The main objective was to make stable dispersions with nanobentonite and sepiolite by using a water soluble polymer as stabilizer. The changes in the rheological properties of bentonite were investigated at various concentrations of polyvinyl alcohol (PVA) to discover the stability of the dispersions. The standard API tests were applied for drilling fluid to determine the properties of dispersions.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1342
Author(s):  
Loredana Dumitrașcu ◽  
Nicoleta Stănciuc ◽  
Iuliana Aprodu

In the current study, the effect of temperature on the potential of soy proteins to ensure the encapsulation and gastric stability of bioactives, such as anthocyanins from cornelian cherry fruits, was investigated. The powders obtained after freeze-drying were analyzed in relation to flow properties, encapsulation retention and efficiency, stability in simulated gastrointestinal medium, color, and morphology. Preheating the soy proteins generated a powder with low density. Powders obtained with native soy proteins allowed the highest encapsulation efficiency and the lowest was obtained when using preheated soy proteins. The heat treatment of the mixture of soy proteins and cornelian cherry fruits prior to encapsulation generated powders with the highest lightness and the lowest intensity of red shades among all samples. The in vitro experiments revealed that the highest protection in simulated gastric environment was provided when protein was heat treated either alone or in combination with bioactives to be encapsulated. The morphological analysis highlighted that powders consisted of large and rigid structures.


2020 ◽  
Vol 10 (6) ◽  
pp. 7120-7134

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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