scholarly journals Rheological Properties of Some Honeys in Liquefied and Crystallised States

2016 ◽  
Vol 60 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Sławomir Bakier ◽  
Krzysztof Miastkowski ◽  
Jan Robert Bakoniuk
Keyword(s):  
Quantitative Analysis ◽  
Shear Rate ◽  
Dynamic Viscosity ◽  
Apparent Viscosity ◽  
Steady Shear ◽  
Dynamic Measurements ◽  
Rheological Measurements ◽  
Rotary Shear ◽  
The Media ◽  
Good Agreement

Abstract The paper presents the results of rheological measurements conducted on three types of Polish honey: rape, multi-floral, and buckwheat honeys. The investigations involved identification of the properties of the honeys in both liquefied (by heating) as well as crystallised states. Both steady shear as well as dynamic rheological tests were performed. As a result, it was possible to show that the liquefied honeys behave like Newtonian fluids. Good agreement of the results between the rotary shear and oscillation rotary tests was observed, thus fulfilling the Cox-Mertz rule. The structure of the honeys was subjected to qualitative scrutiny by analysing photographs of the crystals taken in the conditions of shearing interferometry. The quantitative analysis was made by presenting a numerical distribution of crystal colonies with reference to the maximum dimensions of individual crystals. The geometric measurements of the crystals were carried out using analiSIS software. In the crystallised form, the media showed a thixotropic effect, and their apparent viscosity was many times higher than the dynamic viscosity in the liquid state. After plasticising by deformation with an increasing shear rate of up to 450s−1, the equilibrium melting curves of the crystallised honeys were described by the Ostwald-de Waele model. One particular reason for the research was to show that the results obtained for the honeys crystallised by the steady shear method, were qualitatively different from the results obtained in the dynamic measurements. The Cox-Mertz rule cannot be applied for the crystallised honeys.

Rheological Measurements on Molten Metals

1999 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Measurement Technique ◽  
Dynamic Viscosity ◽  
Apparent Viscosity ◽  
Liquid Metals ◽  
Molten Metals ◽  
Alloy Composite ◽  
Rheological Measurements ◽  
Special Procedure

Abstract The rotational measurement technique has been developed to measure the dynamic viscosity of liquid metals. A special procedure is accomplished to eliminate both end and eccentricity effects. The technique was calibrated and tested with liquids of known rheology. The apparent viscosity of low melting alloy composite is measured by means of the technique.

scholarly journals CHROMATOGRAPHIC, RHEOLOGICAL AND CYTOCHEMISTRY EVALUATION OF “BACURI” PULP (Platonia insignis MART.)

2014 ◽  
Vol 32 (1) ◽  
Author(s):  
ANDRÉA CARDOSO DE AQUINO ◽  
CÍCERO DE SOUZA LIMA ◽  
FILIPE XAVIER FEITOSA ◽  
MARIA IZABEL GALLÃO ◽  
GUSTAVO ADOLFO SAAVEDRA PINTO ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
Physicochemical Characterization ◽  
Effect Of Temperature ◽  
Rheological Measurements ◽  
Cytochemical Analysis ◽  
Linalool Oxide ◽  
Increasing Temperature ◽  
Good Agreement ◽  
Newtonian Behavior

“Bacuri” pulp was evaluated for volatile compounds, rheological behavior, and cytochemical analysis. The pulp was also submitted to physicochemical characterization. The effect of temperature on rheological behavior of whole “bacuri” pulp was investigated in this work. The rheological measurements were carried out using a Brookfield Rheometer (Model DV-II +) at shear rate range from 0.25 to 1.50 s-1 at temperatures of 30, 40, 50, 60 and 70 °C. A total of 36 compounds were detected in the headspace of the “bacuri” pulp - 34 of which were identified. The major compounds were the following: linalool, cis-linalool, trans-linalool oxide, and hotrienol, respectively. The experimental data was adjusted using a power law rheological model, with good agreement. “Bacuri” pulp shows a non-Newtonian behavior, with an apparent viscosity decreasing with increasing temperature. The “bacuri” pulp obtained activation energy at shear rate 1.50 s-1 was -14.03 kJ/mol.

scholarly journals Viscosity and Rheological Properties of Graphene Nanopowders Nanofluids

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 979
Author(s):  
Abderrahim Bakak ◽  
Mohamed Lotfi ◽  
Rodolphe Heyd ◽  
Amine Ammar ◽  
Abdelaziz Koumina
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Dynamic Viscosity ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Heat Extraction ◽  
Rheological Characterization ◽  
Shear Rates ◽  
Rheological Measurements

The dynamic viscosity and rheological properties of two different non-aqueous graphene nano-plates-based nanofluids are experimentally investigated in this paper, focusing on the effects of solid volume fraction and shear rate. For each nanofluid, four solid volume fractions have been considered ranging from 0.1% to 1%. The rheological characterization of the suspensions was performed at 20 ∘C, with shear rates ranging from 10−1s−1 to 103s−1, using a cone-plate rheometer. The Carreau–Yasuda model has been successfully applied to fit most of the rheological measurements. Although it is very common to observe an increase of the viscosity with the solid volume fraction, we still found here that the addition of nanoparticles produces lubrication effects in some cases. Such a result could be very helpful in the domain of heat extraction applications. The dependence of dynamic viscosity with graphene volume fraction was analyzed using the model of Vallejo et al.

Rheological Behavior and Fluidity of Semi-Solid SiCp/A357 Composites with Different SiC Addition Levels

2016 ◽  
Vol 256 ◽  
pp. 126-132 ◽  
Author(s):  
Zhen Lin Zhang ◽  
Zhi Feng Zhang ◽  
Jun Xu ◽  
Wei Min Mao
Keyword(s):  
Shear Rate ◽  
Solid Fraction ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Stir Casting ◽  
Sic Particles ◽  
Semi Solid ◽  
Test Casting ◽  
Good Agreement

The apparent viscosities of the semi-solid SiCp/A357 composites with 0vol.%, 10vol.% and 20vol.% SiC particles manufactured by stir casting were investigated using a Couette type viscometer, and the composite fluidity was examined with a test casting. The results showed that, the viscosities of the semi-solid SiCp/A357 composites decreased with an increase in shear rate, but increased with the increasing of solid fraction, and apparent viscosity of 10vol.% SiCp/A357 composite was the lower than that of 20vol.% SiCp/A357 composite at the same solid fraction; and the composite fluidity results were in a good agreement with the viscosity ones.

Viscosity of Diluted Aqueous K2CO3/KHCO3 Solutions

1992 ◽  
Vol 57 (9) ◽  
pp. 1879-1887 ◽  
Author(s):  
Zdeněk Palatý
Keyword(s):  
Dynamic Viscosity ◽  
Correlation Equation ◽  
Viscosity Data ◽  
Electrolyte Mixtures ◽  
Interaction Coefficients ◽  
Basic Solutions ◽  
Good Agreement

The applicability of the equation derived for calculating the dynamic viscosity of ternary non-electrolyte mixtures, to the correlation of viscosity data of the H2O- K2CO3/KHCO3 system is verified in this work. It was found out that the values of dynamic viscosity obtained experimentally are in good agreement with the viscosity values calculated from this equation. The equation constants - interaction coefficients - were determined from the measurements of dynamic viscosity on mixing the basic solutions of K2CO3 and KHCO3 of known concentration. The correlation equation makes it possible to calculate viscosity of the K2CO3/KHCO3 solutions in the K2CO3 and KHCO3 concentration range from 0 to about 2.0 kmol m-3.

Understanding Populism and Why It Matters

2017 ◽  
Author(s):  
Paul D. Kenny
Keyword(s):  
Quantitative Analysis ◽  
Liberal Democracy ◽  
Political Ideology ◽  
Party Systems ◽  
Negative Consequences ◽  
Political Movement ◽  
Electoral Success ◽  
The Media ◽  
Or Organization ◽  
Populist Party

This chapter discusses the concept of populism in greater detail and also describes how party systems are measured and classified. Rather than conceive of populism as a type of thin political ideology, this book understands populism as a distinctively personalistic type of political movement or organization in which charismatic leaders look to directly mobilize mass constituencies through the media and other means. The chapter next distinguishes between programmatic, patronage, and populist party systems, based on which type of party is most common. Finally, the chapter provides a quantitative analysis of the consequences of populist electoral success for democracy across a number of indicators. It shows that populist rule has generally negative consequences for the functioning of liberal democracy, which makes the effort to understand populist electoral success all the more pressing.

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

Rheological Study on of PBT with High Melt Flow Index

2012 ◽  
Vol 487 ◽  
pp. 644-648
Author(s):  
Yuan Liu ◽  
Lin Wang ◽  
Qing Yan Xu ◽  
Pei Jie Lin ◽  
Zhi Hong Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Flow Activation Energy ◽  
Nonwoven Fabrics ◽  
Flow Activation ◽  
High Flexibility

Melt-blown generated PBT nonwoven fabrics usually have small fibril diameter, high flexibility, well heat and oil resistance. Therefore, they would have promising application such as vehicle filtering media. The rheological behavior of PBT with High Melt Flow Index for Melt-blown is investigated in this paper. It is a direction of the technology design and fabrication parameters .The relation of apparent viscosity and shear rate is analyzed, as well as flow activation energy and Non-Newtonian indexes. The results suggest that PBT with High Melt Flow Index is Non-Newtonian fluid. Apparent viscosity and flow activation energy show gradually decrease with increasing shear rate, exhibiting typical shear-thinning behavior.

Influence of Fillers on the Viscosity Properties of One-Pack Polyurethane Sealants

2021 ◽  
Vol 410 ◽  
pp. 605-610
Author(s):  
Kseniya A. Timakova ◽  
Yuriy T. Panov ◽  
Evgeniy A. Timakov
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Sharp Increase ◽  
Sharp Decrease ◽  
Shear Forces ◽  
Complex Orientation ◽  
Developed Surface ◽  
Mineral Fillers ◽  
Constant Shear Rate ◽  
Shape Of Particles

The paper investigates the effect of fillers on the viscosity properties of one-pack polyurethane sealants. It is noted that with the introduction of such mineral fillers as Mikarb, Midol, MTD2 chalk and aluminum hydroxide, the dynamic viscosity of the composition increases uniformly, while when filled with chemically precipitated Calofort SV chalk and MT-GShM talc, an abnormally sharp increase in viscosity is observed. Such an increase in viscosity for Calofort SV is explained by a highly developed surface, in contrast to other fillers. Talc is characterized by a plate-like shape of particles, which leads to a complex orientation of talc particles in the composition and shear difficulties.It was found that a sealant filled with chemically precipitated chalk has more than 100 pts. wt.(parts by weight), per 100 pts. wt. of the prepolymer under the influence of shear forces (at a constant shear rate) during the first 10 minutes of exposure, a sharp decrease in viscosity is observed, which is characteristic of thixotropic compositions, reaching a constant value after 5-10 minutes. After 10 minutes, the thixotropy of the sealant is restored. Talc does not impart thixotropic properties to the sealant composition.

scholarly journals The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Sulaiman Al-Zuhair, Mirghani I. Ahmed and Yousif A. Abakr
Keyword(s):  
Shear Rate ◽  
Boundary Conditions ◽  
Palm Oil ◽  
Apparent Viscosity ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Optimum Operating ◽  
Crude Palm Oil ◽  
Different Boundary Conditions ◽  
Rotary Viscometer

This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words:  Crude palm oil, apparent viscosity, shear rate, modelling, separation 

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