Rheological model of the lithosphere along profile VII in the Eastern Carpathians

We used 2D integrated geophysical modelling approach to calculate the temperature distribution in the lithosphere along profile VII passing through the Eastern Carpathians. With assigned rheological parameters of rocks and obtained temperature field, we derived the rheological model of the lithosphere along the studied profile. We have calculated the strength distribution in the lithosphere, based on the brittle and ductile deformation, for compressional and extensional regimes and the vertically integrated strength along the profile. To illustrate the strength distribution in different tectonic units, we have calculated the yield strength envelopes for chosen lithospheric columns. Ours results show that the dominant regime is compressional and the largest strength occurs on the boundary between the upper and lower crust. Along the studied profile, the strength decreases from its high values in the European platform towards its minimum in the Trans-European Suture Zone (TESZ). In the Eastern Carpathians, the strength increases, reaches two maxima, the first in the Outer Eastern Carpathians, and the second in the Inner Eastern Carpathians, where the highest values of strength can be observed. Another local maximum along the profile can be observed in the Apuseni Mountains, while the minimal strength is observed in the Transylvanian Basin. The diverse rheological behaviour of studied tectonic units seems to be in accordance with their lithospheric structure and tectonics.

Download Full-text

Calculation of temperature distribution and rheological properties of the lithosphere along Profile 1 passing through Aswan

Contributions to Geophysics and Geodesy ◽

10.1515/congeo-2017-0005 ◽

2017 ◽

Vol 47 (1) ◽

pp. 69-80

Author(s):

Anwar H. Radwan ◽

Jana Dérerová ◽

Miroslav Bielik ◽

Barbora Šimonová ◽

Igor Kohút

Keyword(s):

Temperature Distribution ◽

Upper Mantle ◽

Lower Crust ◽

Strength Distribution ◽

Rheological Parameters ◽

Upper Crust ◽

Temperature Model ◽

Crust And Upper Mantle ◽

Rigid Deformation ◽

Modelling Approach

AbstractThe 2D integrated geophysical modelling approach has been used to determine the temperature distribution in the lithosphere along the profile passing through Aswan. Based on the temperature model and the rheological parameters, we have calculated strength distribution in the lithosphere for the studied profile. The strength envelopes have been calculated for both compressional and extensional regimes. Our results indicate that the strength is constant along the whole length of the profile passing through the Nubia plain. The largest strength can be observed within the upper crust which allows us to assume rigid deformation in this part of the lithosphere, with compressional processes predominant. Towards the lower crust and upper mantle, strength values rapidly decrease for both regimes, suggesting ductile deformations in the lower part of the lithosphere.

Download Full-text

Analytical Rheology of Honey: A State-of-the-Art Review

Foods ◽

10.3390/foods10081709 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1709

Author(s):

Célia Faustino ◽

Lídia Pinheiro

Keyword(s):

Sugar Content ◽

Rheological Behaviour ◽

Principal Component ◽

Rheological Parameters ◽

Experimental Conditions ◽

Thixotropic Behaviour ◽

Ancient Times ◽

Medicinal Properties ◽

Complex Relationships ◽

Temperature Time

Honey has been used as a nutraceutical product since ancient times due to its nutritional and medicinal properties. Honey rheology influences its organoleptic properties and is relevant for processing and quality control. This review summarizes the rheological behaviour of honeys of different botanical source(s) and geographical locations that has been described in the literature, focusing on the relation between rheological parameters, honey composition (moisture, water activity, sugar content, presence of colloidal matter) and experimental conditions (temperature, time, stress, shear rate). Both liquid and crystallized honeys have been addressed. Firstly, the main mathematical models used to describe honey rheological behaviour are presented highlighting moisture and temperature effects. Then, rheological data from the literature regarding distinct honey types from different countries is analysed and results are compared. Although most honeys are Newtonian fluids, interesting shear-thinning and thixotropic as well as anti-thixotropic behaviour have been described for some types of honey. Rheological parameters have also been successfully applied to identify honey adulteration and to discriminate between different honey types. Several chemometric techniques have also been employed to obtain the complex relationships between honey physicochemical and rheological properties, including partial least squares (PLS), principal component analysis (PCA) and artificial neural networks (ANN).

Download Full-text

Hole-Cleaning Fibers Improve Cuttings-Carrying Capacity

Journal of Petroleum Technology ◽

10.2118/0521-0063-jpt ◽

2021 ◽

Vol 73 (05) ◽

pp. 63-64

Author(s):

Chris Carpenter

Keyword(s):

Flow Regime ◽

Carrying Capacity ◽

Rheological Model ◽

Drilling Fluid ◽

Test Method ◽

Abu Dhabi ◽

Rheological Parameters ◽

Cleaning Efficiency ◽

Hole Cleaning ◽

Drilling Operations

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203147, “Investigating Hole-Cleaning Fibers’ Mechanism To Improve Cutting Carrying Capacity and Comparing Their Effectiveness With Common Polymeric Pills,” by Mohammad Saeed Karimi Rad, Mojtaba Kalhor Mohammadi, SPE, and Kourosh Tahmasbi Nowtarki, International Drilling Fluids, prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed. Hole cleaning in deviated wells is more challenging than in vertical wells because of the boycott effect or the eccentricity of the drillpipe. Poor hole cleaning can result in problems such as borehole packoff or excessive equivalent circulating density. The complete paper investigates a specialized fibrous material (Fiber 1) for hole-cleaning characteristics. The primary goal is to identify significant mechanisms of hole-cleaning fibers and their merits compared with polymeric high-viscosity pills. Hole-Cleaning Indices Based on a review of the literature, most effective parameters regarding hole cleaning in different well types were investigated. These parameters can be classified into the following five categories: - Well design (e.g., hole angle, drillpipe eccentricity, well trajectory) - Drilling-fluid properties (e.g., gel strength, mud weight) - Formation properties (e.g., lithology, cutting specific gravity, cuttings size and shape) - Hydraulic optimizations (e.g., flow regime, nozzle size, number of nozzles) - Drilling practices (e.g., drillpipe rotation speed, wellbore tortuosity, bit type, rate of penetration, pump rate) In this research, rheological parameters and parameters of the Herschel-Bulkley rheological model are considered to be optimization inputs to increase hole-cleaning efficiency of commonly used pills in drilling operations. The complete paper offers a detailed discussion of both the importance of flow regime and the role of the Herschel-Bulkley rheological model in reaching a better prognosis of drilling-fluid behavior at low shear rates. The properties of the fibrous hole-cleaning agent used in the complete paper are provided in Table 1. Test Method Two series of tests were performed. The medium of the first series is drilling water, with the goal of evaluating the efficiency of Fiber 1 in fresh pills. The second series of tests was per-formed with a simple polymeric mud as a medium common in drilling operations. Formulations and rheological properties of both test series are provided in Tables 4 and 5 of the complete paper, respectively.

Download Full-text

Biopolymer Drill-in Fluid Performance for Different Rheological Models using Statistical Characterisation

Ghana Mining Journal ◽

10.4314/gm.v19i1.10 ◽

2019 ◽

Vol 19 (1) ◽

pp. 86-92

Author(s):

M. Owusu ◽

H. Osei

Keyword(s):

Rheological Model ◽

Rheological Behaviour ◽

Primary Objective ◽

Least Square ◽

Model Parameters ◽

Drilling Fluids ◽

Cleaning Efficiency ◽

Rheological Models ◽

Least Square Regression ◽

Best Fit

Appropriate selection of rheological models is important for hydraulic calculations of pressure loss prediction and hole cleaning efficiency of drilling fluids. Power law, Bingham-Plastic and Herschel-Bulkley models are the conventional fluid models used in the oilfield. However, there are other models that have been proposed in literature which are under/or not utilized in the petroleum industry. The primary objective of this paper is to recommend a rheological model that best-fits the rheological behaviour of xanthan gum-based biopolymer drill-in fluids for hydraulic evaluations. Ten rheological models were evaluated in this study. These rheological models have been posed deterministically and due to the unrealistic nature have been replaced by statistical models, by adding an error (disturbance) term and making suitable assumptions about them. Rheological model parameters were estimated by least-square regression method. Models like Sisko and modified Sisko which are not conventional models in oil industry gave a good fit. Modified Sisko model which is a four parameter rheological model was selected as the best-fit model since it produced the least residual mean square of 0.61 Ibf2/100ft4. There is 95% certainty that the true best-fit curve lies within the confidence band of this function of interest. Keywords: Biopolymer; Least-Square Regression; Residual Mean Squares; Rheologram

Download Full-text

Rheological Characterization of Highly Concentrated Mineral Suspensions Using Ultrasound Velocity Profiling with Combined Pressure Difference Method

Applied Rheology ◽

10.1515/arh-2008-0020 ◽

2008 ◽

Vol 18 (6) ◽

pp. 62114-1-62114-10 ◽

Cited By ~ 1

Author(s):

Reinhardt Kotzé ◽

Rainer Haldenwang ◽

Paul Slatter

Keyword(s):

Pressure Difference ◽

Laser Doppler Anemometry ◽

Mining Industry ◽

Rheological Behaviour ◽

Ultrasound Velocity ◽

Rheological Parameters ◽

Rheological Characterization ◽

Newtonian Flows ◽

Line Measurement ◽

Mineral Suspensions

Abstract The rheological behaviour of non-Newtonian, highly concentrated and non-transparent fluids used in industry have so far been analysed using commercially available instruments, such as conventional rotational rheometers and tube viscometers. When dealing with the prediction of non-Newtonian flows in pipes, pipe fittings and open channels, most of the models used are empirical in nature. The fact that the fluids or slurries that are used normally are opaque, effectively narrows down the variety of applicable in-line rheometers even further, as these instruments are normally based on laser or visible light techniques, such as Laser Doppler Anemometry. In this research, an Ultrasonic Velocity Profiling technique (UVP), in combination with a pressure difference (PD) measurement, was tested to provide in-line measurement of rheological parameters. The main objective of this research was to evaluate the capabilities of the UVP-PD technique for rheological characterisation of different concentrations of non-transparent non-Newtonian slurries. Kaolin, bentonite, Carboxymethyl Cellulose (CMC) and water solutions were used as model non-Newtonian mining slurries. Results determined by the UVP-PD method were compared with results obtained by off-line rheometry and in-line tube viscometry. The agreement between the UVP-PD method, tube viscometry and conventional rheometry was found to be within 15 % for all of the highly concentrated mineral suspensions investigated over a given range of shear rates. This method, if used in combination with a pressure difference technique (PD), has been found to have a significant potential in the development process of new in-line rheometers for process control within the mining industry.

Download Full-text

Relationship between Rheological Behaviour and Final Structure ofAl2O3and YSZ Foams Produced by Replica

Advances in Materials Science and Engineering ◽

10.1155/2012/549508 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

S. Y. Gómez ◽

O. A. Alvarez ◽

J. A. Escobar ◽

J. B. Rodrigues Neto ◽

C. R. Rambo ◽

...

Keyword(s):

Mechanical Performance ◽

Raw Materials ◽

Rheological Behaviour ◽

Rheological Parameters ◽

Ceramic Structure ◽

Ceramic Foams ◽

Different Types ◽

Binder Type ◽

Ceramic Suspensions ◽

Ceramic Thickness

Using rheological parameters of ceramic suspensions, it is possible to taylor the structure of the ceramic foams produced by replica. This method consists in the impregnation of a polymeric flexible template (polyurethane foam) with a ceramic suspension (slurry) containing the appropriate additives, followed by burning out organic compounds and additives and sintering the ceramic structure. In this work, ceramic foams were produced by the replica method from Al2O3and 3% Y2O3-ZrO2. Rheological parameters of the ceramic suspensions were investigated to improve the mechanical performance of final structures. Different types and quantities of raw materials were combined in order to select the formulations for ceramic foams. The parameters that have a significant influence on the process are the binder type and the amount of solids. Significant changes on the hysteresis area of the suspensions resulted in a lower density of macrodefects in the material. Likewise, when the shear rate viscosity is enhanced, the thickness of the struts increased proportionally. Lastly, when the hysteresis area magnitude and the ceramic thickness increased, the material with higher uniformity was internally densified, and the stress concentration of the internal defects was smoothed

Download Full-text

Ductile shear zones – future perspectives

10.5194/egusphere-egu2020-4273 ◽

2020 ◽

Author(s):

Christoph Schrank

Keyword(s):

Shear Zone ◽

Research Effort ◽

Rheological Behaviour ◽

Shear Zones ◽

Ductile Deformation ◽

Field Observations ◽

Ductile Shear Zones ◽

In Situ Experiments ◽

Ductile Shear ◽

Physical Consequences

About 50 years ago, John Ramsay and colleagues established the thorough foundation for the field-scale observational and mathematical description of the structures, deformation, and kinematics in ductile shear zones. Since then, these probably most important instabilities of the ductile lithosphere enjoyed an almost explosive growth in scientific attention. It is perhaps fair to say that this tremendous research effort featured four main themes:&#160;[1] The historic scientific nucleus &#8211; quantification of shear-zone geometry, strain and associated kinematic history from field observations&#160;[2] Qualitative and quantitative analysis of microphysical deformation mechanisms in the field and the laboratory&#160;[3] Shear-zone rheology&#160;[4] The development of physically consistent mathematical models for shear zones, mainly using continuum mechanics.&#160;In concert, these four cornerstones of shear-zone research enabled tremendous progress in our understanding of why and how ductile shear zones form. So, what are some of the outstanding problems?&#160;A truly comprehensive model for ductile shear zones must account for the vast range of length and time scales involved, each easily covering ten orders of magnitude, as well as the associated intimate coupling between thermal, hydraulic, mechanical, and chemical processes. The multi-scale and multi-physics nature of ductile shear zones generates scientific challenges for all four research themes named above. This presentation is dedicated to highlighting exciting challenges in themes 2, and 3 and 4.&#160;In the microanalytical arena [2], the nano-scale is an exciting new frontier, especially when it comes to the interplay between metamorphism and ductile deformation. The nano-frontier can be tackled with new synchrotron methods. I showcase some applications to fossil shear-zone samples and discuss opportunities for in-situ experiments. In the domain of rheology [3], I present some simple experiments with strain-softening materials and field observations that support the notion: transient rheological behaviour is very important for shear localisation. In the modelling domain [4], some recent examples for the intriguing physical consequences predicted by new multi-physics and cross-scale coupling terms in ductile localisation problems are illustrated.

Download Full-text

The Fractional derivative rheological model and the linear viscoelastic behavior of hydrocolloids

Chemical and Process Engineering ◽

10.2478/v10176-012-0013-2 ◽

2012 ◽

Vol 33 (1) ◽

pp. 141-151 ◽

Cited By ~ 7

Author(s):

Magdalena Orczykowska ◽

Marek Dziubiński

Keyword(s):

Fractional Derivative ◽

Viscoelastic Properties ◽

Rheological Model ◽

Xanthan Gum ◽

Viscoelastic Behavior ◽

Rheological Parameters ◽

Rice Starch ◽

Linear Viscoelastic Behavior ◽

Linear Viscoelastic ◽

The Impact

The Fractional derivative rheological model and the linear viscoelastic behavior of hydrocolloids This study was aimed at evaluating the possibility to use the Friedrich-Braun fractional derivative rheological model to assess the viscoelastic properties of xanthan gum with rice starch and sweet potato starch. The Friedrich-Braun fractional derivative rheological model allows to describe viscoelastic properties comprehensively, starting from the behaviour characteristic of purely viscous fluids to the behaviour corresponding to elastic solids. The Friedrich-Braun fractional derivative rheological model has one more virtue which distinguishes it from other models, it allows to determine the relationship between stress and strain and the impact of each of them on viscoelastic properties on the tested material. An analysis of the data described using the Friedrich-Braun fractional derivative rheological model allows to state that all the tested mixtures of starch with xanthan gum form macromolecular gels exhibiting behaviour typical of viscoelastic quasi-solid bodies. The Friedrich-Braun fractional derivative rheological model and 8 rheological parameters of this model allow to determine changes in the structure of the examined starch - xanthan gum mixtures. Similarly important is the possibility to find out the trend and changes going on in this structure as well as their causes.

Download Full-text

Assessment of Impact of the Rheological Parameters Change on Sensitivity of the Asphalt Strain Based on the Test Results / Ocena Wpływu Zmiany Parametrów Reologicznych Na Wrażliwość Deformacji Mieszanek Mineralno - Asfaltowych Na Podstawie Wyników Badań

Civil and Environmental Engineering Reports ◽

10.1515/ceer-2015-0008 ◽

2015 ◽

Vol 16 (1) ◽

pp. 105-117

Author(s):

Artur Kurpiel ◽

Adam Wysokowski

Keyword(s):

Rheological Properties ◽

Creep Test ◽

Creep Curve ◽

Rheological Model ◽

Rheological Parameters ◽

Test Results ◽

Test Load ◽

Resistance To Deformation ◽

The Impact ◽

Non Destructive

Abstract The creep test under the static loading, that allows to determine rheological properties of asphalt based on the creep curve, is the most effective test nowadays. Applied loads are non-destructive and allow to observe the course of the strain after the test load. The test can be carried out on compressing, shearing, bending as well as on triaxial test, that depends on the applied apparatus implementing different intensity [1, 2, 3, 4, 5, 6]. Based on the creep test, the stress of different properties can be specified. Among them there are valuable rheological properties based on selected viscoelascity models [1]. The properties of the viscoelascity models are relevant indexes depicting resistance to deformation. They can be used to forecast the wheel-truck in the accepted rheological model [1]. In this article it is shown the impact of different rheological properties of the viscoelacity model on the wheel-truck as well as the impact of different properties on shape and the course of the creep curve. The asphalt mixtures presented in this article are characterized by variable rheological properties. It is therefore difficult to determine which property mostly affects the size of the strain. However, the authors of this article attempted to analyse the change of the asphalt strain value of the different variables in particular rheological model, called Bürgers’s model.

Download Full-text

Influence of Fructose and Sucrose on Small and Large Deformation Rheological Behaviour of Heated Amioca Starch Dispersions

Food Science and Technology International ◽

10.1177/1082013204042073 ◽

2004 ◽

Vol 10 (1) ◽

pp. 51-57 ◽

Cited By ~ 10

Author(s):

D. B. Genovese ◽

V. M. Acquarone ◽

K. -S. Youn ◽

M. A. Rao

Keyword(s):

Yield Stress ◽

Large Deformation ◽

Heating Temperature ◽

Ageing Time ◽

Rheological Behaviour ◽

Angular Frequency ◽

Rheological Parameters ◽

Static Yield ◽

Pasting Temperature ◽

Dynamic Yield

Effect of sucrose or fructose on the rheological behaviour of gelatinized 5% w/w amioca starch dispersions (GSDs), was studied by small and large deformation rheological techniques. Storage (G0) and loss (G00) moduli as a function of angular frequency (o), and shear stress (s) as a function of shear rate (_) data were obtained on GSDs with: 0, 30 and 60% w/w sugars. Magnitudes of Herschel–Bulkley yield stress (0-HB) were determined from – _ data. Using the vane method, the static yield stress (0s), the dynamic yield stress (0d) and the shear modulus (G) were determined. Effect of pasting temperature and ageing time were also studied by the vane method. Addition of sugars produced an increase in all rheological parameters except 0d, suggesting that sugars increased the strength of the internal bonds or cohesiveness of the GSDs; in general, fructose was slightly more effective than sucrose. Equivalent parameters: G0 and G, and 0-HB and 0s showed good agreement. Decreasing the heating temperature increased G. GSDs with fructose showed a clear increase in 0s and G with ageing time.

Download Full-text