scholarly journals Estimation of semolina dough rheological parameters by inversion of a finite elements model

2015 ◽  
Vol 46 (3) ◽  
pp. 95
Author(s):  
Angelo Fabbri ◽  
Chiara Cevoli
Keyword(s):  
Finite Elements ◽  
Rheological Properties ◽  
Inverse Method ◽  
Rheological Parameters ◽  
Percentage Error ◽  
Food Material ◽  
Food Engineering ◽  
Traditional Procedure ◽  
The Difference ◽  
Finite Elements Model

The description of the rheological properties of food material plays an important role in food engineering. Particularly for the optimisation of pasta manufacturing process (extrusion) is needful to know the rheological properties of semolina dough. Unfortunately characterisation of non-Newtonian fluids, such as food doughs, requires a notable time effort, especially in terms of number of tests to be carried out. The present work proposes an alternative method, based on the combination of laboratory measurement, made with a simplified tool, with the inversion of a finite elements numerical model. To determine the rheological parameters, an objective function, defined as the distance between simulation and experimental data, was considered and the well-known Levenberg-Marqard optimisation algorithm was used. In order to verify the feasibility of the method, the rheological characterisation of the dough was carried also by a traditional procedure. Results shown that the difference between measurements of rheological parameters of the semolina dough made with traditional procedure and inverse methods are very small (maximum percentage error equal to 3.6%). This agreement supports the coherence of the inverse method that, in general, may be used to characterise many non-Newtonian materials.

scholarly journals Newly Developed Correlations to Predict the Rheological Parameters of High-Bentonite Drilling Fluid Using Neural Networks

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2787
Author(s):  
Ahmed Gowida ◽  
Salaheldin Elkatatny ◽  
Khaled Abdelgawad ◽  
Rahul Gajbhiye
Keyword(s):  
Rheological Properties ◽  
Drilling Fluid ◽  
Rheological Parameters ◽  
Percentage Error ◽  
Cleaning Efficiency ◽  
Periodic Monitoring ◽  
Data Points ◽  
Ann Models ◽  
Artificial Neural Network Ann ◽  
Marsh Funnel

High-bentonite mud (HBM) is a water-based drilling fluid characterized by its remarkable improvement in cutting removal and hole cleaning efficiency. Periodic monitoring of the rheological properties of HBM is mandatory for optimizing the drilling operation. The objective of this study is to develop new sets of correlations using artificial neural network (ANN) to predict the rheological parameters of HBM while drilling using the frequent measurements, every 15 to 20 min, of mud density (MD) and Marsh funnel viscosity (FV). The ANN models were developed using 200 field data points. The dataset was divided into 70:30 ratios for training and testing the ANN models respectively. The optimized ANN models showed a significant match between the predicted and the measured rheological properties with a high correlation coefficient (R) higher than 0.90 and a maximum average absolute percentage error (AAPE) of 6%. New empirical correlations were extracted from the ANN models to estimate plastic viscosity (PV), yield point (YP), and apparent viscosity (AV) directly without running the models for easier and practical application. The results obtained from AV empirical correlation outperformed the previously published correlations in terms of R and AAPE.

scholarly journals A New Mixed Functional-probabilistic Approach for Finite Element Accuracy

2020 ◽  
Vol 20 (4) ◽  
pp. 799-813
Author(s):  
Joël Chaskalovic ◽  
Franck Assous
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Asymptotic Relation ◽  
Probabilistic Approach ◽  
Random Variable ◽  
High Order ◽  
Relative Accuracy ◽  
The Difference ◽  
New Perspective

AbstractThe aim of this paper is to provide a new perspective on finite element accuracy. Starting from a geometrical reading of the Bramble–Hilbert lemma, we recall the two probabilistic laws we got in previous works that estimate the relative accuracy, considered as a random variable, between two finite elements {P_{k}} and {P_{m}} ({k<m}). Then we analyze the asymptotic relation between these two probabilistic laws when the difference {m-k} goes to infinity. New insights which qualify the relative accuracy in the case of high order finite elements are also obtained.

scholarly journals Influence of biopolymers on the rheological properties of seafloor sediments and the runout behavior of submarine debris flows

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jun Kameda ◽  
Hamada Yohei
Keyword(s):  
Rheological Properties ◽  
Debris Flows ◽  
Extracellular Polymeric Substances ◽  
Flow Behavior ◽  
Mass Movement ◽  
Rheological Parameters ◽  
Natural Environments ◽  
Natural Systems ◽  
Chemical Conditions ◽  
Seafloor Sediments

AbstractSubmarine debris flows are mass movement processes on the seafloor, and are geohazards for seafloor infrastructure such as pipelines, communication cables, and submarine structures. Understanding the generation and run-out behavior of submarine debris flows is thus critical for assessing the risk of such geohazards. The rheological properties of seafloor sediments are governed by factors including sediment composition, grain size, water content, and physico-chemical conditions. In addition, extracellular polymeric substances (EPS) generated by microorganisms can affect rheological properties in natural systems. Here we show that a small quantity of EPS (~ 0.1 wt%) can potentially increase slope stability and decrease the mobility of submarine debris flows by increasing the internal cohesion of seafloor sediment. Our experiments demonstrated that the flow behavior of sediment suspensions mixed with an analogue material of EPS (xanthan gum) can be described by a Herschel–Bulkley model, with the rheological parameters being modified progressively, but not monotonously, with increasing EPS content. Numerical modeling of debris flows demonstrated that the run-out distance markedly decreases if even 0.1 wt% of EPS is added. The addition of EPS can also enhance the resistivity of sediment to fluidization triggered by cyclic loading, by means of formation of an EPS network that binds sediment particles. These findings suggest that the presence of EPS in natural environments reduces the likelihood of submarine geohazards.

Study of the physical, chemical and rheological properties of oil mixtures transported through the Uzen - Atyrau - Samara pipeline

2021 ◽  
pp. 420-427
Author(s):  
Берик Картанбаевич Саяхов ◽  
Александр Геннадьевич Дидух ◽  
Гульнара Амангельдиевна Габсаттарова ◽  
Марат Давлетович Насибулин ◽  
Жасулан Канатович Наурузбеков
Keyword(s):  
Rheological Properties ◽  
Pour Point ◽  
Heating Temperature ◽  
High Viscosity ◽  
Rheological Parameters ◽  
Polarization Microscopy ◽  
Oil Pipeline ◽  
Physical Chemical ◽  
Wide Range ◽  
Oil Mixtures

На начальных участках магистрального нефтепровода Узень - Атырау - Самара формируются партии низкозастывающих бузачинских и высокозастывающих мангышлакских нефтей. По маршруту транспортировки осуществляются дополнительные подкачки нефтей с различными физико-химическими и реологическими характеристиками, что может оказывать существенное влияние на свойства перекачиваемых нефтесмесей. Цель настоящей работы - исследование физико-химических и реологических свойств бузачинской и мангышлакской нефтесмесей на маршруте поставки Узень - Атырау, а также диапазона и причин изменений характеристик бузачинской нефти (основной в компонентном составе нефтесмесей, перекачиваемых по нефтепроводу Узень - Атырау - Самара). По результатам исследований установлено, что свойства мангышлакской нефтесмеси изменяются в незначительных пределах. Для бузачинской нефтесмеси свойственна нестабильность реологических параметров, которые могут изменяться в широком диапазоне в результате путевой подкачки на различных участках нефтепровода. Колебания реологических параметров наиболее показательных проб партий бузачинской нефтесмеси рекомендуется учитывать для решения задач повышения текучести высоковязких нефтей и оптимизации технологических режимов работы трубопроводов, по которым осуществляется перекачка таких нефтей. Методами газохроматографического анализа молекулярно-массового распределения тугоплавких парафинов и поляризационной микроскопии определена температура нагрева бузачинской и мангышлакской нефтесмесей, оптимальная для ввода депрессорной присадки. At the initial sections of the Uzen - Atyrau - Samara main oil pipeline, batches of low pour point Buzachinsky and high pour point Mangyshlak oils are formed. Additional pumping of oils with different physical, chemical and rheological characteristics is carried out along the transportation route, which can have a significant effect on the properties of the pumped oil mixtures. The purpose of this study is to examine the physical, chemical and rheological properties of Buzachi and Mangyshlak oil mixtures on the Uzen - Atyrau supply route, as well as the range and causes of changes in the characteristics of Buzachinsky oil (the main oil mixture in the blend composition pumped through the Uzen - Atyrau - Samara pipeline). According to the research results, it was found that the properties of the Mangyshlak oil mixture vary within insignificant limits. The Buzachinsky oil mixture is characterized by instability of rheological parameters, which can vary in a wide range as a result of route pumping at different pipeline sections. Fluctuations of the rheological parameters of the most indicative samples of batches of the Buzachinsky oil mixture are recommended to be taken into account in order to increase the fluidity of high-viscosity oils and optimize the process modes of operation of pipelines through which such oils are pumped. Using the methods of gas chromatographic analysis of the molecular weight distribution of high-melting-point paraffins, as well as polarization microscopy, the optimal heating temperature for the introduction of a pour point depressant into the Buzachinsky and Mangyshlak oil mixtures has been determined.

RHEOLOGICAL PROPERTIES OF HUMIC SUBSTANCES OF PEAT AND BROWN COAL

2021 ◽  
pp. 169-174
Author(s):  
Ivan I. Lishtvan ◽  
Vera N. Aleinikova
Keyword(s):  
Rheological Properties ◽  
Humic Substances ◽  
Structure Formation ◽  
Humic Substance ◽  
Brown Coal ◽  
Oil Wells ◽  
Alkaline Media ◽  
Rheological Parameters ◽  
Acid Media ◽  
Brown Coals

Knowledge about structure and rheological peculiarities of drilling solutions and reagents applied for the proceeding of oil wells has significant value for the forecasting of oil wells drilling. The research results of the structure of the humic substances of peat and brown coals precipitated in different pH ranges from the standpoint of their ability to structure formation on the base of the rheological curves obtaining of the flow of their dispersions and determining of their rheological parameters in terms of their application in drilling practice are given in the article. It is established that during transition from fraction, beset into alkaline media (12.0–8.5) to fraction beset into acid media (5.0–2.0) the decrease of the rheological indicators of caustobiolate humic substance is occurred. Rheological curves of the flow of the disperse of caustobiolate humic substances of the fraction 1 and 2 are characterized for strong fossil structures, disperses of humic substances of the fraction 3 is for less strong coagulation structures. Less structured are humic substances of brown coal so that their use is preferable for the regulation of the structure and rheological peculiarities of drilling solutions.

scholarly journals HOTS (Higher Order Thinking Skill) Based Monopoly Development as Learning Media for Animal and Food Materials

2020 ◽  
Vol 5 (2) ◽  
pp. 83-87
Author(s):  
Rischa Dwi Arianti ◽  
Arfilia Wijayanti ◽  
Filia Prima Artharina
Keyword(s):  
Higher Order Thinking ◽  
Development Stage ◽  
Higher Order ◽  
Research Model ◽  
Thinking Skill ◽  
Food Material ◽  
Implementation Phase ◽  
Class Average ◽  
Evaluation Stage ◽  
The Difference

This research model uses several stages, namely the analysis phase, the design phase, the development stage, the implementation phase, the evaluation stage. The results showed the difference in class average between classes using media and not using monopoly media based on HOTS (Higher Order Thinking Skill). This is evidenced by the results of the t-test in which the number of t arithmetic (3,590)> ttable (1,708). So the result is effectiveness in the use of HOTS (Higher Order Thingking Skill) based animal and food material monopoly in grade IV SD 01 Kalicari.

scholarly journals Bias and error in modelling thermochronometric data: resolving a potential increase in Plio-Pleistocene erosion rate

2021 ◽  
Vol 9 (5) ◽  
pp. 1153-1221
Author(s):  
Sean D. Willett ◽  
Frédéric Herman ◽  
Matthew Fox ◽  
Nadja Stalder ◽  
Todd A. Ehlers ◽  
...  
Keyword(s):  
Error Analysis ◽  
Inverse Method ◽  
Synthetic Data ◽  
Systematic Bias ◽  
Exhumation Rate ◽  
Erosion Rates ◽  
The Difference ◽  
Path Lengths ◽  
Using Data ◽  
Exhumation History

Abstract. Thermochronometry provides one of few methods to quantify rock exhumation rate and history, including potential changes in exhumation rate. Thermochronometric ages can resolve rates, accelerations, and complex histories by exploiting different closure temperatures and path lengths using data distributed in elevation. We investigate how the resolution of an exhumation history is determined by the distribution of ages and their closure temperatures through an error analysis of the exhumation history problem. We define the sources of error, defined in terms of resolution, model error and methodological bias in the inverse method used by Herman et al. (2013) which combines data with different closure temperatures and elevations. The error analysis provides a series of tests addressing the various types of bias, including addressing criticism that there is a tendency of thermochronometric data to produce a false inference of faster erosion rates towards the present day because of a spatial correlation bias. Tests based on synthetic data demonstrate that the inverse method used by Herman et al. (2013) has no methodological or model bias towards increasing erosion rates. We do find significant resolution errors with sparse data, but these errors are not systematic, tending rather to leave inferred erosion rates at or near a Bayesian prior. To explain the difference in conclusions between our analysis and that of other work, we examine other approaches and find that previously published model tests contained an error in the geotherm calculation, resulting in an incorrect age prediction. Our reanalysis and interpretation show that the original results of Herman et al. (2013) are correctly calculated and presented, with no evidence for a systematic bias.

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