Literatura científica selecionada sobre o tema "From viscosimetry to rheometry"
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Artigos de revistas sobre o assunto "From viscosimetry to rheometry"
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Figueroa-Ochoa, Edgar Benjamín, Lourdes Mónica Bravo-Anaya, Ricardo Vaca-López, Gabriel Landázuri-Gómez, Luis Carlos Rosales-Rivera, Tania Diaz-Vidal, Francisco Carvajal, Emma Rebeca Macías-Balleza, Yahya Rharbi e J. Félix Armando Soltero-Martínez. "Structural Behavior of Amphiphilic Triblock Copolymer P104/Water System". Polymers 15, n.º 11 (31 de maio de 2023): 2551. http://dx.doi.org/10.3390/polym15112551.
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A detailed study of the different structural transitions of the triblock copolymer PEO27–PPO61–PEO27 (P104) in water, in the dilute and semi-dilute regions, is addressed here as a function of temperature and P104 concentration (CP104) by mean of complimentary methods: viscosimetry, densimetry, dynamic light scattering, turbidimetry, polarized microscopy, and rheometry. The hydration profile was calculated through density and sound velocity measurements. It was possible to identify the regions where monomers exist, spherical micelle formation, elongated cylindrical micelles formation, clouding points, and liquid crystalline behavior. We report a partial phase diagram including information for P104 concentrations from 1 × 10−4 to 90 wt.% and temperatures from 20 to 75 °C that will be helpful for further interaction studies with hydrophobic molecules or active principles for drug delivery.
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WAGNER, Oliver, Herwig SCHÜLER, Peter HOFMANN, David LANGER, Peter DANCKER e Juergen BEREITER-HAHN. "Sound attenuation of polymerizing actin reflects supramolecular structures: viscoelastic properties of actin gels modified by cytochalasin D, profilin and α-actinin". Biochemical Journal 355, n.º 3 (24 de abril de 2001): 771–78. http://dx.doi.org/10.1042/bj3550771.
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Polymerization and depolymerization of cytoskeletal elements maintaining cytoplasmic stiffness are key factors in the control of cell crawling. Rheometry is a significant tool in determining the mechanical properties of the single elements in vitro. Viscoelasticity of gels formed by these polymers strongly depends on both the length and the associations of the filaments (e.g. entanglements, annealings and side-by-side associations). Ultrasound attenuation is related to viscosity, sound velocity and supramolecular structures in the sample. In combination with a small glass fibre (2mm×50µm), serving as a viscosity sensor, an acoustic microscope was used to measure the elasticity and acoustic attenuation of actin solutions. Changes in acoustic attenuation of polymerizing actin by far exceed the values expected from calculations based on changes in viscosity and sound velocity. During the lag-phase of actin polymerization, attenuation slightly decreases, depending on actin concentration. After the half-maximum viscosity is accomplished and elasticity turns into steady state, attenuation distinctly rises. Changes in ultrasound attenuation depend on actin concentration, and they are modulated by the addition of α-actinin, cytochalasin D and profilin. Thus absorption and scattering of sound on the polymerization of actin is related to the packing density of the actin net, entanglements and the length of the actin filaments. Shortening of actin filaments by cytochalasin D was also confirmed by electron micrographs and falling-ball viscosimetry. In addition to viscosity and elasticity, the attenuation of sound proved to be a valuable parameter in characterizing actin polymerization and the supramolecular associations of F-actin.
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Götz, Joachim, Hartmut Balzer e Ruth Hinrichs. "Characterisation of the Structure and Flow Behaviour of Model Chocolate Systems by Means of NMR and Rheology". Applied Rheology 15, n.º 2 (1 de abril de 2005): 98–111. http://dx.doi.org/10.1515/arh-2005-0005.
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Abstract In order to characterise the structure and flow behaviour of model chocolate systems Nuclear Magnetic Resonance (NMR) and rheometry were used to determine the T1 - and T2 - NMR relaxation times and their corresponding flow functions. T1 and T2 characterise the molecular mobility of fluids and correlate with both the zero-shear-rate and infinity viscosity of various chocolate model systems (determined with rotational rheometry and capillary rheometry). Based on this correlation, NMR provides the possibility to determine characteristic viscosities of chocolate masses by means of NMR-relaxation experiments. The viscosities of chocolate masses are important process parameters, as they are used for quality control of the production process. An online process viscosimetry via T2 relaxation would allow the installation of an efficient process control and, thus, a process automation. This NMR application with comparatively short measuring times is especially interesting for disperse systems where the use of conventional rheometric techniques may cause large errors. The only prerequisite for the measurement of the viscosities using NMR is a previous calibration. This was performed with the help of rotational and capillary rheometry. The NMR self-diffusion experiments are especially appropriate to characterise the influence of emulsifiers on the structure and the flow behaviour of chocolate masses.
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Strobelt, Jonas, Joerg Bauer, Marc Dreissigacker, Ole Hoelck, Tanja Braun, Karl-Friedrich Becker, Martin Schneider-Ramelow e Klaus-Dieter Lang. "COMBINING ADVANTAGES OF RHEOMETRY AND INLINE VISCOMETRY FOR IMPROVED VISCOSITY MODELING". International Symposium on Microelectronics 2019, n.º 1 (1 de outubro de 2019): 000568–72. http://dx.doi.org/10.4071/2380-4505-2019.1.000568.
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Abstract In microelectronic packaging, encapsulation by compression and transfer molding is a crucial process block to ensure device reliability. Material properties of encapsulants, highly filled systems of reactive epoxy molding compounds (EMC), strongly depend on process conditions in a complex manner and vary over time. Shear-thinning behavior, as well as time- and temperature-dependent conversion strongly impact the viscosity of the polymer melt. In all fields of application, such as automotive or IoT, demands towards miniaturization, lifetime and environmental conditions increase. Thus, detailed understanding of the complex material behavior is of vital importance. Typically, shear-thinning behavior of polymer melts is characterized using a conventional rheometer in oscillation mode under varying shear-rates and temperatures. Limitations of this approach are, that measurements at process temperature typically cannot be performed due to the high reactivity of the encapsulant at these temperatures (e.g. 175 °C for transfer molding). Therefore extrapolation to the correct temperature range is required. Furthermore, measurements in oscillation mode cannot necessarily be transferred to real process conditions, where a continuous flow is present. To overcome these limitations the inline viscometer can be used, a specially designed measurement tool for a transfer molding machine developed by Fico/Besi. The polymer melt is pressed through a narrow slit under known volumetric flow at process temperature. By measuring the pressure difference before and after the slit, the viscosity can be calculated. In order to better understand and also predict material behavior, inline viscosimetry is combined with rheometer measurements. This allows to maintain the advantages of conventional rheometry regarding material consumption and large shear-rate measuring range. At the same time, the inline approach provides relevant data under process conditions. The synthesis of both approaches yields a correction of the rheometer measurements, ultimately improving viscosity modeling and being an improved basis for process simulation.
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Faria, Hugo, F. M. Andrade Pires e A. Torres Marques. "Modeling the rheology of SR1500 and LY556 epoxies under manufacturer's recommended cure cycles after viscosimetry and rheometry characterization". Polymer Engineering & Science 54, n.º 4 (24 de junho de 2013): 831–39. http://dx.doi.org/10.1002/pen.23607.
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Tan, Grace, Weizhong Zou, Mike Weaver e Ronald G. Larson. "Determining threadlike micelle lengths from rheometry". Journal of Rheology 65, n.º 1 (janeiro de 2021): 59–71. http://dx.doi.org/10.1122/8.0000152.
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Manzhai, V. N., S. G. Kulyshkina, L. V. Chekantseva e I. G. Yashchenko. "COMPOSITION AND STRUCTURE OF HIGH-VISCOSITY OILS FROM VARIOUS DEPOSITS". Oil and Gas Studies, n.º 1 (1 de março de 2018): 112–18. http://dx.doi.org/10.31660/0445-0108-2018-1-112-118.
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The article presents the results of investigations of oil samples from various deposits. The samples contain asphaltenes, resins and paraffins in different concentrations. It is established that all oil samples are non-Newtonian fluids and they have pseudoplastic properties. Due to the results of experiments, which were carried out by the method of rotational viscosimetry, size of complex structural units of oils at various sliding velocities was calculated.
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Postema, Michiel, Christine Gering, Nicole Anderton, Craig S. Carlson e Minna Kellomäki. "Monitoring the gelation of gellan gum with torsion rheometry and brightness-mode ultrasound". Current Directions in Biomedical Engineering 8, n.º 2 (1 de agosto de 2022): 33–36. http://dx.doi.org/10.1515/cdbme-2022-1010.
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Abstract Gellan gum is a hydrogel with several applications in ultrasonic imaging, novel drug delivery, and tissue regeneration. As hydrogels are dynamic entities, their viscocelastic and therefore their acoustic properties change over time, which is of interest to monitor. To determine the speed of sound from brightness-mode images, however, rather large quantities of hydrogel are needed. In this study, we investigated torsion rheometry as a means to determine acoustic properties. Perceived speeds of sound were derived and computed from torsion rheometry measurements of gelating gellan gum mixed with spermidine trihydrochloride crosslinker. For comparison, brightness-mode ultrasonic images were recorded of the same material inside a phantom well. The rheometry data converged to a speed of sound within a standard devitation of the speed of sound measured from the brightness-mode images.We have shown that dynamic acoustic properties of gelating gellan gum can be simulated and experimentally determined using torsion rheometry.
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Schindler, Ralf, Elke Weichselsdorfer, Oliver Wagner e Jürgen Bereiter-Hahn. "Aldolase-localization in cultured cells: Cell-type and substrate-specific regulation of cytoskeletal associations". Biochemistry and Cell Biology 79, n.º 6 (1 de dezembro de 2001): 719–28. http://dx.doi.org/10.1139/o01-137.
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The role of aldolase as a true F- and G-actin binding protein, including modulating actin polymerization, initiating bundling, and giving rise to supramolecular structures that emanate from actin fibrils, has been established using indirect immunofluorescence, permeabilization of XTH-2 cells and keratocytes, and microinjection of fluorescence-labeled aldolase. In addition, binding to intermediate filaments, vimentin, and cytokeratins has been demonstrated. In permeabilized cells in the presence of fructose-1,6-bisphosphate (202000 µM) aldolase shifts from association with actin fibres to intermediate filaments. Plenty of free binding sites on microtubules have been revealed by addition of fluorochromed aldolase derived from rabbit skeletal muscle. However, endogenous aldolase was never found associated with microtubules. Differences in actin polymerization in the presence of aldolase as revealed by pyrene-labeled actin fluorimetry and viscosimetry were explained by electron microscopy showing the formation of rod-like structures (10 nm wide, 2060 nm in length) by association of aldolase with G-actin, which prevents further polymerization. Upon the addition of fructose-1,6-bisphosphate, G-actinaldolase mixture polymerizes to a higher viscosity and forms stiffer filaments than pure actin of the same concentration.Key words: aldolase, cytoskeleton, electron microscopy, viscosimetry.
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Kavehpour, H. P., e G. H. McKinley. "Tribo-Rheometry: From Gap-Dependent Rheology to Tribology". Tribology Letters 17, n.º 2 (agosto de 2004): 327–35. http://dx.doi.org/10.1023/b:tril.0000032471.06795.ea.
Texto completo da fonteTeses / dissertações sobre o assunto "From viscosimetry to rheometry"
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Paschoal, Mateus Faria de Andrade. "Mouvement de particules magnétiques dans un fluide à seuil". Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0240.
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Cette thèse présente une investigation approfondie, mettant en œuvre des approches expérimentales et numériques, sur un viscosimètre à chute de bille modifié utilisé pour déterminer les propriétés rhéologiques des fluides. Le fluide étudié ici est le Carbopol, modélisé comme un fluide de type Herschel-Bulkley. Il s'agit d'une gamme de fluides appelés fluides viscosplastiques, caractérisés par une contrainte seuil d'écoulement et d'un comportement rhéofluidifiant sous écoulement. Initialement, la configuration classique du viscosimètre, à savoir une bille soumise à la gravité tombant dans un tube rempli de fluide viscoplastique, a été analysée expérimentalement. Les résultats expérimentaux pour cette configuration classique concordent avec la littérature : pour de faibles valeurs de contrainte seuil, la bille tombe avec une vitesse verticale constante. L'analyse des données obtenues dans ces conditions a révélé des effets de confinement, mettant en évidence le défi de la reproductibilité dans l'expérience classique de la boule tombante. Pour résoudre cette problématique, une nouvelle configuration de viscosimètre a été proposée en introduisant un aimant permanent dans le système pour contrôler la dynamique de la bille lors de sa chute, assurant ainsi des données reproductibles. Dans ce nouvel dispositif, la compréhension de toutes les forces agissant sur la bille et leur influence sur sa dynamique est cruciale. Tout d'abord, les efforts se sont portés sur la détermination de la force magnétique par des approches analytiques et numériques, validées par des mesures expérimentales. Les trajectoires des données expérimentales du viscosimètre modifié ont ensuite été comparées pour valider le calcul de cette force nouvellement ajoutée. Les résultats démontrent que tandis que l'analyse de la position radiale reste difficile, les données de position verticale concordent avec les simulations. Afin de compléter les données de la littérature, la force de traînée seule a également été étudiée dans la configuration classique du viscosimètre. Un développement détaillé a été réalisé pour étudier la force de traînée statique, le résultat obtenu correspond la valeur bien connue de la littérature. Par des approches analytiques et numériques, nous aboutissons à une nouvelle corrélation pour le coefficient de traînée qui inclue cette force statique, les propriétés rhéologiques du fluide d'Herschel-Bulkley mais aussi les paramètres géométriques, notamment le rapport des rayons du tube et de la bille. Ce travail enrichit la littérature existante en fournissant de résultats originaux et en présentant de nouvelles perspectives par l'ajout d'une force de volume connue qui vient modifier la dynamique de la billeThis thesis presents an in-depth investigation, using experimental and numerical approaches, on a modified falling ball viscometer used to determine the rheological properties of fluids. The fluid studied here is Carbopol, modeled as a Herschel-Bulkley type fluid. This is a range of fluids called viscoplastic fluids, characterized by a yield stress and shear-thinning behavior under flow. Initially, the classic configuration of the viscometer, i.e., a ball subject to gravity falling in a tube filled with viscoplastic fluid, was analyzed experimentally. The experimental results for this classic configuration align with the literature: for low yield stress values, the ball falls with a constant vertical velocity. The analysis of the data obtained under these conditions revealed confinement effects, highlighting the challenge of reproducibility in the classic falling ball experiment. To address this issue, a new viscometer configuration was proposed by introducing a permanent magnet into the system to control the dynamics of the ball during its fall, thus ensuring reproducible data. In this new device, understanding all the forces acting on the ball and their influence on its dynamics is crucial. First, efforts focused on determining the magnetic force through analytical and numerical approaches, validated by experimental measurements. The trajectories of the experimental data from the modified viscometer were then compared to validate the calculation of this newly added force. The results show that while the analysis of the radial position remains difficult, the vertical position data align with the simulations. To complement the literature data, the drag force alone was also studied in the classic viscometer configuration. A detailed development was carried out to study the static drag force, and the result obtained matches the well-known value in the literature. Through analytical and numerical approaches, we arrive at a new correlation for the drag coefficient that includes this static force, the rheological properties of the Herschel-Bulkley fluid, as well as geometric parameters, notably the tube-to-ball radius ratio. This work enriches the existing literature by providing original results and presenting new perspectives by adding a known volumetric force that modifies the ball’s dynamics
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Zeman, Jan. "Studium interakcí polyelektrolytů s kladně nabitými dusíkatými amfifilními látkami". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216955.
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The study deals with interactions of polyelectrolytes polystyrene sulfonate and hyaluronic acid with nitrogenic amphiphilic substances, represented by lysine and albumine. To study the interactions pH-metry, conductance, viscositic and turbidity measurement, DLS and reometry were used. All mixtures of different concentrations were measured and the data were compered with data obtained from measurement of samples with amphiphilic sumstances without polyelectrolytes. Observed interactions occured in the aminoacid concentrations between 0 to 20 mmoldm-3, then the PSS interaction groups were fully bonded by lysine and no more interactions were recognized. The same behaviour were observed in albumine solutions with concentration under 2 gdm-3.
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Nguyen, Tien Cuong. "In-situ and ex-situ multi-scale physical metrologies to investigate the destructuration mechanisms of lignocellulosic matrices and release kinetics of fermentescible cellulosic carbon". Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0036/document.
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La bioconversion des biomasses lignocellulosiques est actuellement un grand défi pour le développement de technologies de bio-raffinage. Le manque de connaissances des mécanismes de liquéfaction et de saccharification est l’un des principaux facteurs qui pénalisent le développement des procédés de bio-raffinage. Ce travail est centré sur le développement d’analyses physiques et biochimiques in-situ (viscosimétrie, focus beam reflectance measurement) et ex-situ (rhéometrie, granulométrie laser, morphogranulométrie, sédimentation…) pour améliorer la compréhension des mécanismes de déstructuration desfibres lignocellulosiques et caractériser les cinétiques de libération de carbone fermentescible. Des substrats modèles (cellulose microcristalline, papier Whatman) et industriels (pâte à papier, bagasse de canne à sucre) ont été utilisés avec différentes conditions d'hydrolyse (1% à 30%w/v, 0.1 à 0.5mL enzyme/ g cellulose). Les résultats obtenus ont permis:- de proposer et de valider les mesures in-situ de la viscosité de la suspension et de la distribution des longueurs de corde des particules, ainsi que sa conversion en distribution de diamètre.- de montrer l'impact de la nature et de la concentration de substrat et des ratios enzyme/substrat sur les évolutions des paramètres physico-biochimiques lors de l'hydrolyse. Ces effets ont été quantifiés sur les limitations de transfert.- d'établir un modèle phénoménologique de comportement rhéologique des suspensions initiales- de montrer que les cinétiques physico et bio-chimiques sont des cinétiques du second ordre- de montrer que, pour des hydrolyses à haute teneur en matière sèche, on peut réduire considérablement la limitation des transferts liée aux hautes concentrations et contrôler la cinétique de production de glucose par une stratégie d’ajouts cumulés desubstratIn the context of biofuels and chemicals production of petroleum substitutes from renewable carbon, bioconversion of lignocellulose biomasses is currently a major challenge. The limited knowledge of liquefaction and saccharification mechanisms stands as the main factor which penalizes bio-refinery progress. The present work is centred on the development of in-situ(viscosimetry, focus beam reflectance measurement) and ex-situ (rheometry, diffraction light scattered, morphometry, decantation…) physical and biochemical analysis to expand our understanding of the destructuration mechanisms of lignocellulose fibres and to characterise the release kinetics of fermentable cellulosic carbon. Model (microcrystalline cellulose,Whatman paper) and industrial (paper-pulp, sugarcane bagasse) lignocellulose matrices under a large range of hydrolysis conditions (1% up to 30%w/v and 0.1 up to 0.5mL enzyme/g cellulose) were studied during 24h hydrolysis experiments (pertinent period to appreciate transfer limitations). Our scientific results allow:- to propose and validate the in-situ measurements of the suspension viscosity and chord length distribution together with its conversion into particle size distribution.- to demonstrate the impact of the substrate nature and concentration and of the enzymatic ratios on the evolution of physical- and biochemical parameters during hydrolysis. Their impacts on transfer phenomena were quantified.- to establish phenomenological models for rheological behaviour of initial suspensions.- to describe all physical (viscosity, particle size) and biochemical (substrate and product) kinetics by second order reaction models.- to demonstrate that, for high dry matter concentration hydrolysis, a cumulative feeding substrate strategy allows considerably reducing the transfer limitations linked to high concentrations and to control the glucose production kinetics
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Goswami, Rituparna. "Characterization of the nuclear envelope mechano- transduction in Arabidopsis : from supracellular stress to chromatin remodeling". Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAJ102.
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Les cellules végétales détectent et répondent à divers stimuli mécaniques externes comme le toucher ou le vent, et internes comme la pression osmotique et la tension des parois cellulaires. Dans cette étude, j'ai démontré que la forme et la rigidité du noyau sont affectées de manière réversible en condition de stress hyperosmotique et sont corrélées à l’expression de gènes. Afin d'identifier les bases moléculaires de cette réponse, nous avons étudié différents mutants. En particulier, les protéines GIP lient cytosquelette, enveloppe nucléaire et chromatine ; nous avons observé que le mutant gip1gip2 présente une réponse nucléaire de type hyperosmotique constitutive et acquiert même une résistance physiologique au stress hyperosmotique. De façon plus exploratoire, j’ai commencé à analyser l’impact du nucléosquelette (mutant crwn1) et de la paroi (mutant eli1) sur la forme des noyaux et leurs réponses au stress hyperosmotique. Notre étude ouvre le champ de la mécanotransduction nucléaire chez les plantes, et offre de nombreuses perspectivesPlant cells sense and respond to external mechanical stimuli such as touch or wind, and to internal mechanical stimuli, such as turgor pressure and cell wall tension. In this study I have demonstrated that the nuclear shape and mechanics are impacted upon hyperosmotic stress in a reversible manner and are correlated with gene expression. To identify the molecular bases of this response, we have investigated different mutants. First the GIP proteins are at the nexus between cytoskeleton, nuclear envelope, and chromatin. We found that the gip1gip2 mutant defects exhibits a constitutive hyperosmotic nuclear response and is already primed to resist hyperosmotic stress. As a more exploratory work, I also analysed the contribution of the nucleoskeleton (crwn1 mutant) and cell wall (eli1 mutant) on nucleus behaviour in response to hyperosmotic stress. Our study opens the path to nuclear mechanotransduction in plants, while also offering several prospects for future research in this area
Capítulos de livros sobre o assunto "From viscosimetry to rheometry"
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Kulicke, Werner-Michael, e Christian Clasen. "Determination of the Polymer Coil Dimensions from the Intrinsic Viscosity". In Viscosimetry of Polymers and Polyelectrolytes, 91–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-10796-6_7.
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Laun, H. M. "Wall Slip of Polymer Melts From Squeeze Flow and Capillary Rheometry". In Progress and Trends in Rheology V, 26–29. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_9.
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Fuller, Gerald G. "Design of Optical Instruments". In Optical Rheometry of Complex Fluids, 149–80. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195097184.003.0008.
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Abstract The design of an optical instrument begins with a consideration of the structural and dynamic information that is desired from a sample, and their relationship to its optical properties. This information must be combined with the particular flow or sample geometry that will be probed and the timescales of the dynamics to be monitored.
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Fuller, Gerald G. "Propagation of Electromagnetic Waves". In Optical Rheometry of Complex Fluids, 3–22. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195097184.003.0001.
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Abstract The experimental methods presented in this monograph concern the interaction of light with complex materials for the purpose of elucidating aspects of structure and dynamics. The interactions range from simple transmission and reflection, to scattering and nonlinear responses. Measurement of changes in the properties of the light (polarization, intensity, or frequency) is used to infer the microstructural characteristics of the sample and for this reason, the basic nature of light propagation in macroscopic media must be understood. This chapter presents the basic field equations governing the propagation of electromagnetic waves and the boundary conditions by which they are constrained.
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Fuller, Gerald G. "Microstructural Theories of Optical Properties". In Optical Rheometry of Complex Fluids, 109–48. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195097184.003.0007.
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Abstract The optical measurements presented in the previous chapters can be used to either characterize local, microstructural properties or as probes of bulk responses to orientation processes. In either case, it is normally desirable to make the connection between experimental observables and their molecular or microstructural origins. The particular molecular properties that are probed will naturally depend on the physical interaction between the light and the material. This chapter explores molecular models and theories that describe these interactions and identifies the properties of complex materials that can be extracted from measurements of optical anisotropies. The presentation begins with a discussion of molecular models that are applied to polymeric materials. Using these models, optical phenomena such as birefringence, dichroism, and Rayleigh and Raman scattering are predicted. Models appropriate for particulate systems are also developed.
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Fuller, Gerald G. "Reflection and Refraction of Light: Ellipsometry". In Optical Rheometry of Complex Fluids, 45–51. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195097184.003.0003.
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Abstract Light reflected or refracted from a planar interface will be altered in its phase and amplitude. Measurement of the transfonnation of light following such an interaction can be used to characterize physical properties of the interface. If a thin film is contained at the surface between two media, for example, its refractive index and thickness can be determined. Polarimetry methods used to measure the electric vector emitted in the process of reflection or refraction are commonly referred to as ellipsometry, although, in principle, this term can be used interchangeably with polarimetry to describe any technique used to measure the polarization properties of light. In this chapter, the analysis of light interactions with planar interfaces containing any number of stratified thin films is discussed. The treatment of this topic is necessarily brief, and the monograph by Azzam and Bashara [5] is recommended for a more detailed discussion of ellipsometry.
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Taborda, Esteban, Yurany Villada, Lady J. Giraldo, Diana A. Estenoz, Camilo A. Franco e Farid B. Cortés. "Application of nanotechnology in the petroleum industry: A view from Rheology". In Rheological Measurement Techniques and Analysis Methods [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1004893.
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The objective of this chapter is to demonstrate the use of rheology as a fundamental tool for fluid characterization in processes of the oil industry assisted by nanotechnology. In more detail, the chapter will present three important processes in the oil and gas industry: (i) increase the mobility and transport conditions of heavy and extra-heavy crude oil, (ii) improve the performance of drilling fluids, and (iii) improve polymer injection technology in enhanced recovery (EOR) processes, through the use of nanomaterials. To this end, steady-state rheometry and dynamic rheology are incorporated to understand the phenomena and relate the performance and microstructure of the fluids used. The content of the chapter presents interesting results of a disruptive technology of great importance to the energy industry in general. It will be of great technical contribution to the readers of the book.
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C.Clark, R. "Extensional viscosity of some food hydrocolloids". In Gums and stabilisers for the Food industry 6, 73–85. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780199632848.003.0007.
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Abstract Conventional rheological techniques such as steady shear viscosity and dynamic oscillatory rheometry have long been used to characterize differences between hydrocolloid solutions. Useful information on structure and conformation has been obtained in this way. A complementary method, extensional viscosity, is now available to study these solutions. The newly released Rheometrics Extensional Rheometer (RFX) measures extensional viscosity by means of an opposing jet design. The fluid being tested is drawn into two opposing nozzles from a test beaker. The area between the nozzles undergoes an extensional flow. Such instruments are called stagnation point devices and have been used to study molecular alignment via optical techniques. However, these devices were not able to quantitate the extensional viscosity.
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Naveed, Muhammad. "Advances in measuring mechanical properties of soil in relation to soil health". In Advances in measuring soil health, 215–40. Burleigh Dodds Science Publishing, 2021. http://dx.doi.org/10.19103/as.2020.0079.15.
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Although mechanical properties of soil are fast and easy to measure, they have not been used as indicators of soil health apart from cone penetration resistance. The confined compression test is traditionally used for the prediction of soil compaction risks. Other mechanical tests such as soil rheometry, miniature indentation test, and tensile strength are used for assessing the impact of certain amendments on the stability of the soil. Rheological techniques are appropriate to investigate microstructural stability of soil on a particle-particle scale. Miniature indentation test is very useful to perform when mechanical properties of soil are required to measure at the mm scale. Measurement of the tensile strength of soil has an advantage as it eliminates the effect of water content. There is clearly a need for more practical and rigorous testing on comparing different mechanical properties of the soil to test how they perform relative to each other.
Trabalhos de conferências sobre o assunto "From viscosimetry to rheometry"
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Estellé, Patrice, Christophe Lanos, Yannick Mélinge, Arnaud Perrot, Albert Co, Gary L. Leal, Ralph H. Colby e A. Jeffrey Giacomin. "Couette Rheometry from Differential Approach: Comparative Study and Experimental Application". In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964587.
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Talmon, Arno, Ebi Meshkati e Floris van Rees. "Lessons Learned, and Pitfalls to Avoid in Modern Rheometry". In The 20th International Conference on Transport and Sedimentation of Solid Particles. Wydawnictwo Uniwersytetu Przyrodniczego we Wrocławiu (WUELS Publishing House)), 2023. http://dx.doi.org/10.30825/4.14-13.2023.
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Rheometry is the measurement of rheological properties. Rheometry is essential to understanding and quantifying the flow behaviour of non-Newtonian fluids. Results may differ from one research group to another, or from machine to machine. We will address discrepancies that may arise from the conversion of the machine’s rotational velocity to physical shear rate, ill-defined protocols, the occurrence of wall slip, (bottom) gap size variations, and differences in sample preparation. We confine ourselves to materials consisting of fine colloidal constituents, which form a homogenous carrier fluid with eventual coarse material augmenting the rheology, but are inert by themselves and prone to jamming your rheometer or may settle during the rheometric measurement. Wall slip may occur in rheometry, especially in smooth-walled geometries. Wall slip transpires when the composition of the mixture near the wall differs from that in the interior. A method to identify wall slip in rheometry involves comparing flow curves obtained from various geometrical dimensions, such as pipe/capillary diameter, sheared gap size, or radical testing with vane. Coarse constituents may promote wall slip, but surprisingly, we also encountered it in natural fluid mud without coarse particles. Measurements show that the narrow bottom gap, the mechanical default of the concerned rheometer using vanes, impacts results. The application of dedicated protocols to measure specific properties is another crucial aspect that is emphasized in this paper.
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Läuger, Jörg, Michael Krenn, Albert Co, Gary L. Leal, Ralph H. Colby e A. Jeffrey Giacomin. "From Sample Changer to the Robotic Rheometer: Automation and High Throughput Screening in Rotational Rheometry". In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964515.
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Andertova´, Jana, e Frantisˇek Rieger. "Rheology and Rotational Rheometry of Concentrated Clay Based Ceramic Suspensions: Steps From Measured to Relevant Data". In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-38487.
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The rheological behavior of ceramic suspensions affects significantly wet ceramic processing. On the base of knowledge of rheological parameters the technological parameters of various processes (mixing, batching, spray drying, slip casting, of rheological parameters the selection of proper geometry and sensors must be done. From the data measured the flow curves must be designed and parameters of appropriate rheological models must be calculated. The power-law is the simplest model mostly used for description of rheological behavior of non-Newtonian fluids. Using this model, the dependence of shear stress on shear rate can be expressed. The aim of this paper is to show how the flow curves necessary for parameters of rheological model evaluation can be obtained from primary experimental data received from measurements on rotational viscometer. The two arrangements of rotational viscometer method were used in rheological measurements. The procedure of experimental data to obtain parameters K (coefficient of consistency) and n (flow behavior index) is presented.
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Ahmadzadegan, Arash, Anil Saigal e Michael A. Zimmerman. "Numerical and Experimental Measurements of Die Swell for a LCP and an Amorphous Polymer". In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63723.
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It is known that liquid crystalline polymer (LCP) melts have a high elasticity which can be measured from its effect on the rheology on the cessation of shear. On the other hand, LCPs show very limited die swell after extrusion. In this paper, the results of experimental measurements of the die swell for a liquid crystalline material and polypropylene (PP), an amorphous polymer, are presented. The extrudate thickness 5 cm below the die lip is optically measured and the results are analyzed using ImageJ software. A numerical simulation of the die swell based on the capillary rheometry data and oscillatory rheometry is performed for LCP materials using ANSYS ® POLYFLOW ®. Different viscoelastic properties are used to model the LCP and optimum properties to model the die swell for the base volume flow rate are determined. Results show similarity between die swell modeling for the LCP at the base volume flow rate but increasing the die swell results in some deviation from the experimental results.
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Plohl, Gregor, e Günter Brenn. "Measurement of polymeric time scales from linear drop oscillations". In ILASS2017 - 28th European Conference on Liquid Atomization and Spray Systems. Valencia: Universitat Politècnica València, 2017. http://dx.doi.org/10.4995/ilass2017.2017.4686.
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The oscillating drop method allows material properties of liquids to be measured from damped drop oscillations. Theliterature discusses, e.g., the measurement of the liquid dynamic viscosity and the surface tension against the ambient medium, predominantly for Newtonian liquids. We use this method for measuring pairs of material properties of polymeric liquids. Pairs of properties may be measured, since the quantity measured is a complex frequency with a real and an imaginary part. For the measurements, individual drops are levitated in air by an ultrasonic levitator and imaged with a high-speed camera. Amplitude modulation of the ultrasound drives shape oscillations of the levitated drop. When the modulation is switched off, with the levitating force maintained, the drop performs free oscillations which are damped due to the liquid viscosity. The data acquired from the images recorded are the angular frequency and the damping rate which are used as an input into the characteristic equation of the oscillating drop. Our measurements intend to yield either two viscoelastic time scales with the zero-shear viscosity known, or one time scale and the zero-shear viscosity, with the other time scale known. The two time scales are the stress relaxation and the deformation retardation times. The latter is difficult to get for polymer solutions.The present contribution presents results from a large set of measurements of the deformation retardation time. Liquids studied are aqueous solutions of poly(acryl-amides) at varying concentration. The corresponding values of the zero-shear viscosity agree well with the values from shear rheometry. Values of the deformation retardation time differ substantially from the values commonly used in viscoelastic flow simulations. Furthermore, the measured values disagree with the predictions from the viscous-elastic stress splitting approach in linear viscoelasticity. With our study we will provide a consistent set of material properties for the Oldroyd-B model in linear viscoelasticity. This will beimportant for material modelling in viscoelastic spray simulations.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4686
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Bazargan, Vahid, e Boris Stoeber. "Formation of Temporary Separating Walls in Microfluidic Devices". In ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2008. http://dx.doi.org/10.1115/icnmm2008-62360.
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This work demonstrates a new mechanism for changing the architecture of microfluidic channels during device operation. This method uses an aqueous solution of a thermally responsive polymer (Pluronic), which undergoes reversible gel formation at elevated temperatures. This gelation temperature is lowered through the presence of sodium phosphate. A phase diagram for this material system is derived from rheometry experiments. Formation of a temporary gel wall in a microfluidic device occurs at the diffusive interface between a Pluronic solution and a sodium phosphate solution. The wall thickness increases along the channel, and it decreases at high flow rates. The wall thickness also increases with saline concentration. These observations are explained through scaling arguments for the diffusion problem and with the established phase diagram.
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AlSofi, Abdulkareem M., e Waleed A. Dokhon. "Toward Deep Diversion for Waterflooding and EOR: From Representative Delayed Gelation to Practical Field-Trial Design". In SPE Improved Oil Recovery Conference. SPE, 2022. http://dx.doi.org/10.2118/209457-ms.
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Abstract Conformance control via near-wellbore mechanical and chemical treatments is well established. However, for extreme heterogeneities, effective conformance control mandates deep treatments. Such deep treatments or diversion would sustain sweep enhancement far from wells, deep into the reservoir. Deep diversion is even more mandatory for enhanced oil recovery (EOR) to assure the expensive injectants optimally contact the remaining oil. In this paper, we comprehensively present efforts to research, develop, and trial a crosslinked-gel system for deep diversion. We started by reviewing conformance control options including crosslinked systems. The review supported the immaturity of deep conformance control. Various gel-based solutions, especially preformed particle gels (PPGs) and colloidal dispersed gels (CDGs), were proposed; however, diversion effects were not clearly illustrated. For crosslinked-gels, all systems exhibited fast gelation, something suitable for near-wellbore treatments. We then studied the key crosslinked systems. We characterized their behavior using rheometry, bottle tests, and single-phase corefloods. We assessed their potential through oil-displacement corefloods in artificially fractured cores with and without in-situ imaging. In-house studies, on key gel systems demonstrated the feasibility of gels to affect diversion and enhance recovery but corroborated the extreme challenge to design systems with delayed gelation. To assure representative gelation, we developed, and utilized a continuous bi-directional injection protocol to assess gelation times in-situ. From there, we collaboratively developed, and characterized a unique delayed-gelation formulation. The collaborative study addressed this challenge where systems with delayed gelation were developed. In-situ gelation time estimation confirmed this delayed gelation capacity. Further corefloods addressed the key uncertainties including injectivity losses, limited propagation, and ineffective blockage. Simulations were performed to assess the process feasibility.The simulation studies supported the utility of deep diversion treatments. Simulation also guided the initial design of a trial. We focused on the design of a practical field trial.For further derisking, the first trial was optimized to serve as a practical proof-of-concept. Taking into account economics, success measurement, flow assurance, and depth of placement, we diverged from a trial where we observe deep diversion (and infer delayed gelation and effective blockage) then converged into a trial where we infer deep diversion (by observing delayed gelation and effective blockage). With that, we screened candidates with a clear hierarchy of screening criteria. Through this program, and for the first-time in the industry, we demonstrate the potential utility and feasibility of a crosslinked-gel system for deep diversion applications. This potential is supported by comprehensive experimentation including novel in-situ estimation of gelation times. Finally, a consistent workflow to design a practical field trial is laid out. This, in terms of design considerations and hierarchal screening, is believed to be of extreme value to the practicing reservoir engineers.
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Ochoa, O. O., e P. A. Parker. "Electrical Resistance Measurements in Carbon-Carbon Composites". In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-1203.
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Abstract In-situ electrical resistance measurements of carbon-carbon laminates were obtained in an oxidizing environment at 900 C. Scanning electron and optical microscopy were utilized to interpret the physical damage incurred from oxidation and its impact on the mechanical and electrical properties of the carbon-carbon substrate. The interpretation of the relationships between the percent mass loss, shear modulus, and electrical resistance provided an excellent venue to design future tests. Rescor 780 alumina oxide castable ceramic test fixture used for the electrical resistance measurement was designed and fabricated in our lab. Microscopy observations of specimens exposed for forty minutes revealed preferential fiber loss in both longitudinal and transverse directions. Rheometry tests revealed that the in-plane shear modulus degraded with increasing oxidation time and mass loss. On the other hand the electrical resistance increased with increasing oxidation time and mass loss. The electrical resistance change is controlled primarily by the bulk electrical resistivity, which is a matrix controlled characteristic. As oxidation time increased, the electrical properties of the specimen approached those of the matrix. The carbon-carbon specimens used had four constituents; Silicon carbide (SiC) coating at the top and bottom surfaces of the substrate composed of T-300 carbon fibers, carbon matrix, and the oxidation inhibitor boron carbide (B4C) which chemically react with oxygen and become boric oxide (B2O3). Each of these four components contributes to the oxidation characterization of the specimen and can be represented by a simple, parallel electrical resistance model. Consequently, for a given value of either the shear modulus, electrical resistance, or mass loss the other two values can be easily obtained. The results show that the analytical simulation is on average within 4.7% of the averaged experimental value. Correlation between the shear modulus and the electrical resistance is illustrated in Figure 1.
Relatórios de organizações sobre o assunto "From viscosimetry to rheometry"
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Mittermayr, D., W. Roland e J. Fischer. Investigating the effect of liquid state decontamination on the material properties of post-consumer high impact polystyrene recyclate. Universidad de los Andes, dezembro de 2024. https://doi.org/10.51573/andes.pps39.ss.cep.8.
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The global focus on environmental sustainability has intensified the need for innovative plastic waste management solutions, especially in the food packaging industry. This study explores liquid state decontamination processes of recyclates produced by post-consumer waste recycling of polystyrene yogurt cups and their effects on the material properties of the recycled material. For this purpose, different decontamination processes based on a twin-screw extruder with vacuum degassing and an industrial-scale recycling machine were applied. Tests such as tensile testing, Charpy impact testing, melt flow rate (MFR) measurement, plate-plate rheometry, high-pressure capillary rheometry (HCR), and differential thermal analysis (DTA) were conducted to assess the mechanical and thermo-rheological properties as well as the oxidation induction temperature as an indicator of polymer degradation. The findings provide a comprehensive understanding of the achievable properties of polystyrene from post-consumer waste and reveal insights into the different process-induced degradation processes of the recycled polystyrene.