scholarly journals Temperature Effects on Rheological Properties of Fresh Thickened Copper Tailings that Contain Cement

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Wang ◽  
Aixiang Wu ◽  
Zhuen Ruan ◽  
Hongjiang Wang ◽  
Yiming Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Rheological Properties ◽  
Yield Stress ◽  
Apparent Viscosity ◽  
Temperature Effects ◽  
Underground Mining ◽  
Effect Of Temperature ◽  
Large Temperature ◽  
Pipeline Transport

Cemented paste backfill (CPB) is an economic and environmental friendly technique applied in underground mining for supporting surrounding rock and replacing the pillar. However, little is known about the temperature effects on CPB in mines having a large temperature fluctuation. The main purpose of this research was to investigate the effect of temperature change on the rheological properties (e.g., shear stress and apparent viscosity) of CPB with copper mine tailings. Specifically, a series of rheological tests were conducted on 6 CPB samples using a Brookfield R/S+ Rheometer under various temperatures (2°C, 10°C, 20°C, 30°C, 40°C, and 60°C). Our results showed that both shear stress and apparent viscosity of these tailing samples increased with temperature rising from 2 to 60°C. Likewise, temperature has a significant impact on the Bingham yield stress of thickened tailings. The yield stress decreased from 122 Pa (2°C) to 112 Pa (20°C) and then increased to 152 Pa (60°C). Moreover, the pipeline transport pressure drop of CPB at various temperatures was calculated, illustrating an obvious effect on the paste pipeline transport. Compared with 20°C, the pressure drop under 2°C and 60°C increased by 11% and 22%, respectively. The results of this study indicate that the temperature plays an essential role in determining rheological properties of CPB and its engineering application in mines particularly with naturally fluctuating temperatures.

scholarly journals RHEOLOGICAL ANALYSIS OF VEGETABLE OILS USED FOR BIODIESEL PRODUCTION IN BRAZIL

2015 ◽  
Vol 14 (2) ◽  
pp. 31 ◽  
Author(s):  
L. E. Silva ◽  
C. A. C. Santos ◽  
J. E. S. Ribeiro ◽  
C. C. Souza ◽  
A. M. S. Sant’Ana
Keyword(s):  
Shear Stress ◽  
Rheological Properties ◽  
Vegetable Oils ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Biodiesel Production ◽  
Viscosity Data ◽  
Concentric Cylinder ◽  
Lower Shear ◽  
Different Temperatures

Rheology attempts to define a relationship between the stress acting on a given material and the resulting deformation and/or flow that takes place. Thus, the knowledge of rheological properties of fluid materials such as vegetable oils generates auxiliary data that can be used in its storage and application. In this context, the aim of this study was to evaluate the rheological behavior of vegetable oils (cotton, canola, sunflower, corn and soybean) at different temperatures, using four rheological models (Ostwald- de-Waelle, Herschel-Bulkley, Newton and Bingham). The rheological properties were determined using a Thermo Haake rheometer with concentric cylinder geometry. Measurements were taken at 30, 45 and 60 °C by controlling the temperature using a thermostatic bath coupled to the equipment. The software Rheowin Pro Job Manager was used for process control and data record. The rheograms were obtained by measuring the values of shear stress varying the shear rate from 100 to 600 s-1 within 250 seconds. For the analysis of the apparent viscosity at different shear rates was applied simple linear regression until 2nd degree with the aid of SAS (SAS/Stat 9.2) program. The apparent viscosity data were submitted to analysis of variance and the averages were compared by Tukey test at 5% of probability. Higher temperatures of the samples were correlated to lower shear stress values, hence lower values for viscosity and consistency index were obtained, since it is known that the density and viscosity are highly sensitive to temperature and that the increase in temperature results in reduction of viscosity, benefiting the fluid flow. The models of Newton and Ostwald-de-Waelle were chosen to evaluate the rheological behavior of the samples, showing a good fit for the rheological data.

Flow Behaviors of Commercial Food Thickeners Used for the Management of Dysphagia: Effect of Temperature

2012 ◽  
Vol 8 (2) ◽  
Author(s):  
Se-Ra Hong ◽  
Dong-Soo Sun ◽  
Whachun Yoo ◽  
Byoungseung Yoo
Keyword(s):  
Shear Stress ◽  
Yield Stress ◽  
Flow Behavior ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
High Shear ◽  
Flow Properties ◽  
Different Temperatures ◽  
Management Of Dysphagia ◽  
Arrhenius Temperature

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.

scholarly journals Studying the Rheological Properties of Non-Newtonian Fluids under the Effect of temperature Using Different Chemical Additives

2020 ◽  
Vol 21 (2) ◽  
pp. 47-56
Author(s):  
Douaa Hussein Ali ◽  
Muhannad A.R. Mohammed
Keyword(s):  
Rheological Properties ◽  
Yield Point ◽  
Apparent Viscosity ◽  
Methyl Cellulose ◽  
Plastic Viscosity ◽  
Newtonian Fluids ◽  
Effect Of Temperature ◽  
Chemical Additives ◽  
Bingham Plastic ◽  
Low Viscosity

   This research studies the rheological properties ( plastic viscosity, yield point and apparent viscosity) of Non-Newtonian fluids under the effect of temperature using different chemical additives, such as (xanthan gum (xc-polymer), carboxyl methyl cellulose ( High and low viscosity ) ,polyacrylamide, polyvinyl alcohol, starch, Quebracho and Chrome Lignosulfonate). The samples were prepared by mixing 22.5g of bentonite with 350 ml of water and adding the additives in four different concentrations (3, 6, 9, 13) g by using Hamilton Beach mixer. The rheological properties of prepared samples were measured by using Fan viscometer model 8-speeds. All the samples were subjected to Bingham plastic model. The temperature range studied is from 50 to 200 °F. The results shows that the rheological properties (plastic viscosity, apparent viscosity and yield point) decreased as temperature increased for all prepared samples of non-Newtonian fluids.

Rheology of pulp suspensions of bleached sugarcane bagasse: Effect of consistency and temperature

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 601-606 ◽  
Author(s):  
JORGE H. SÁNCHEZ ◽  
GERMÁN C. QUINTANA ◽  
MERY E. FAJARDO
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Yield Stress ◽  
Sugarcane Bagasse ◽  
Power Law ◽  
Apparent Viscosity ◽  
Power Law Model ◽  
Pulp Suspensions ◽  
Concentric Cylinders ◽  
Rate Controlled

Rheological properties, such as yield stress and apparent viscosity, of pulp suspensions of bleached sugarcane bagasse were studied in a stress-shear rate controlled rheometer using concentric cylinders geometry. Results were statistically analyzed and presented as a function of the suspension consistency (0.5% ≤ Cm ≤ 4.0%) and temperature (20°C, 40°C, and 60°C). The yield stress was influenced by the consistency and temperature. The apparent viscosity was influenced only by the consistency. A power law model was fitted to the experimental results of yield stress. In flow tests, all the suspensions showed shear-thinning behavior, which was in agreement with the Carreau-Yasuda model.

Effect of temperature and concentration on density and rheological properties of melon (Cucumis melo L. var. Inodorus) juice

2014 ◽  
Vol 44 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Ali Mohamadi Sani ◽  
Ghazaleh Hedayati ◽  
Akram Arianfar
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Apparent Viscosity ◽  
Flow Behavior ◽  
Effect Of Temperature ◽  
Plastic Behavior ◽  
Linear Quadratic ◽  
Concentric Cylinder ◽  
Rotational Viscometer ◽  
Content Type

Purpose – The aim of this study was to measure the apparent viscosity, flow behavior and density of melon juice as a function of temperature and juice concentration and to obtain simple equations to correlate experimental data. Design/methodology/approach – Melon juice was concentrated in a rotary evaporator to 40±1, 52.5±1 and 65±1°Brix at 50°C, 80 rpm and stored at 4°C until analysis. Density of melon juice was determined with 25 ml pycnometer at 15, 25 and 35°C and was expressed as kg/m3. All experiments were conducted in triplicate. Experimental data were fitted to different models (linear, quadratic, exponential, quadratic exponential and polynomial) using Minitab 16. Significant differences in the mean values were reported at p<0.05. The flow behavior of melon juice was determined using a concentric cylinder rotational viscometer at shear rate range of 13.2-330 s−1 and temperatures of 15, 25 and 35°C. The experimental data were analyzed Slide Write V7.01 Trial Size (p<0.05) and the rheograms was plotted by Microsoft Excel 2007. Findings – Results showed that the four-term polynomial model is the best model for computing density values from temperature and concentration (R2=0.999). The measured shear stress was within 1.69-780 Pa, corresponding to viscosity range of 0.016-0.237 Pa · s. Within the tested conditions, the concentrate exhibited a pseudo plastic behavior. Temperature had an inverse effect on shear stress and apparent viscosity. Originality/value – No research had been done on production of melon juice concentrate.

Rheological properties of two high polymers suspended in an abrasive slurry jet

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 186-193
Author(s):  
Xinyong Wang ◽  
Dapeng Zhou ◽  
Guodong Zhu ◽  
Chuwen Guo
Keyword(s):  
Rheological Properties ◽  
Newtonian Fluid ◽  
Apparent Viscosity ◽  
Methyl Cellulose ◽  
Effect Of Temperature ◽  
Abrasive Particles ◽  
Nonlinear Fitting ◽  
Abrasive Slurry Jet ◽  
Series Of Experiments ◽  
Carboxy Methyl

Abstract With high polymer added into suspension, the use of abrasive slurry jet (ASJ) has significant advantages in energy management. The quality and efficiency of ASJ are affected distinctly by its structure and the flow field feature, both of which depend on the rheological properties of the abrasive slurry. Therefore, this paper carries out a series of experiments to study the rheological properties of abrasive slurry with polyacrylamide (PAM) and carboxy methyl cellulose (CMC) commonly used in ASJ. The paper also explores the effect of temperature and abrasive on the apparent viscosity of the abrasive slurry. Experimental results show that PAM and CMC solutions behave as a pseudoplastic non-Newtonian fluid in the selected concentration range, whose apparent viscosity increases with the concentration. In addition, specific non-Newtonian fluid constitutive equations of the power-law model for PAM and CMC solution were obtained by nonlinear fitting calculation. The apparent viscosity decreases with the growth of temperature because it leads to the increase in spacing between molecules, making the attraction between molecules smaller and smaller. However, the abrasive has no influence on the apparent viscosity of abrasive slurry for these molecular bonds, and their mechanical entanglements are not destroyed by abrasive particles in the suspension.

scholarly journals Rheological properties of tomato ketchup

10.5219/1161 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 730-734
Author(s):  
Vojtěch Kumbár ◽  
Sylvie Ondrušíková ◽  
Šárka Nedomová
Keyword(s):  
Shear Stress ◽  
Shear Strain ◽  
Rheological Properties ◽  
Apparent Viscosity ◽  
Shear Thinning ◽  
Flow Behaviour ◽  
Flow Index ◽  
Strain Rates ◽  
Shear Strain Rate ◽  
Tomato Ketchup

The objective of this paper was to determine the rheological properties especially shear stress and apparent viscosity vs. shear strain rate, and density of commercially available but also homemade tomato ketchup. The effect of tomato content of density and apparent viscosity of tomato ketchup was also described. Shear stress and apparent viscosity were observed in shear strain rates range from 0.1 s-1 up to 68 s-1. All measurements were carried out at a constant temperature of 22 °C. Experimental results were modeled using a power-law (also known as Ostwald-de Waele) model (R2 ranged from 0.9508 up to 0.9991). The flow behaviour of all measured tomato ketchup samples exhibited non-Newtonian pseudoplastic (shear thinning) behavior where the flow index (n) showed values between 0 and 1. Flow index (n) and consistency coefficient (K) can be used especially in numerical simulation of the flow behaviour of pseudoplastic (shear thinning) liquids.

scholarly journals Field-Dependent Rheological Properties of Graphite Based Magnetorheological Grease

2021 ◽  
Author(s):  
Nur Alyaa Mohd Nasir ◽  
Nurhazimah Nazmi ◽  
Norzilawati Mohamad ◽  
Ubaid Ubaidillah ◽  
Nur Azmah Nordin ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Apparent Viscosity ◽  
Reference Sample ◽  
Chain Structure ◽  
Environmental Scanning ◽  
Application Performance ◽  
Field Dependent ◽  
Linear Viscoelastic ◽  
Near Future

Abstract The utilization of high viscous grease as a medium in Magnetorheological grease (MRG) has benefits in avoiding the sedimentation from occurred, however, it limits the expansion of yield stress in on-state condition thus reduced the application performance upon operation. Therefore, in present study, improvement of the rheological properties of MRG has been investigated by introduction of graphite as an additive. MRG with 10 wt% of graphite (GMRG) was fabricated and the analysis of the properties was compared to the reference sample, MRG. The microstructure of GMRG was characterized through Environmental Scanning Electron Microscope, (ESEM). While, the rheological properties including apparent viscosity, yield stress and viscoelastic properties for both samples were examined using shear rheometer under rotational and oscillatory mode. The results demonstrated slightly increment of apparent viscosity in GMRG and shows a significant improvement in term of yield stress by 38.8% at 3A with growth about 32.7% higher compared to MRG from 0A to 3A. Also, an expansion of linear viscoelastic region (LVE) from 0.01 to 0.1% was observed in the GMRG credited to the domination of elastic properties on the sample. These results obtained was confirmed based on ESEM that displayed the contribution of graphite towards constructing more stable chain structure in GMRG. In conclusion, this study highlights the influence of graphite towards improving the rheological properties of MRG. Hence, addition of graphite in MRG is a great potential to be applied in many applications in near future.

scholarly journals Rheological Performance of Magnetorheological Grease with Embedded Graphite Additives

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5091
Author(s):  
Nur Alyaa Mohd Nasir ◽  
Nurhazimah Nazmi ◽  
Norzilawati Mohamad ◽  
Ubaidillah Ubaidillah ◽  
Nur Azmah Nordin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Rheological Properties ◽  
Yield Stress ◽  
Apparent Viscosity ◽  
Chain Structure ◽  
Environmental Scanning ◽  
Application Performance ◽  
Linear Viscoelastic ◽  
Near Future ◽  
Scanning Electron

The use of highly viscous grease as a medium in magnetorheological grease (MRG) provides the benefit of avoiding sedimentation from occurring. However, it limits the expansion of yield stress in the on-state condition, thus reducing the application performance during operation. Therefore, in this study, the improvement in the rheological properties of MRG was investigated through the introduction of graphite as an additive. MRG with 10 wt % graphite (GMRG) was fabricated, and its properties were compared to a reference MRG sample. The microstructure of GMRG was characterized using an environmental scanning electron microscope (ESEM). The rheological properties of both samples, including apparent viscosity, yield stress, and viscoelasticity, were examined using a shear rheometer in rotational and oscillatory modes. The results demonstrated a slight increase in the apparent viscosity in GMRG and a significant improvement in yield stress by 38.8% at 3 A with growth about 32.7% higher compared to MRG from 0 to 3 A. An expansion of the linear viscoelastic region (LVE) from 0.01% to 0.1% was observed for the GMRG, credited to the domination of the elastic properties on the sample. These obtained results were confirmed based on ESEM, which described the contribution of graphite to constructing a more stable chain structure in the GMRG. In conclusion, the findings highlight the influence of the addition of graphite on improving the rheological properties of MRG. Hence, the addition of graphite in MRG shows the potential to be applied in many applications in the near future.

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