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Auswahl der wissenschaftlichen Literatur zum Thema „Effets fluides“
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Zeitschriftenartikel zum Thema "Effets fluides"
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Fruman, D. H., und F. Beuzelin. „Effets thermiques dans la cavitation des fluides cryogéniques“. La Houille Blanche, Nr. 7-8 (Dezember 1992): 557–61. http://dx.doi.org/10.1051/lhb/1992057.
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Laycock, Dallin P., Rick D. Schroeder und Reza Safari. „Breaking boulders: experimental examination of hydraulic fracturing in the Montney Formation“. Bulletin of Canadian Energy Geoscience 71, Nr. 1 (01.03.2024): 41–62. http://dx.doi.org/10.35767/gscpgbull.71.1.41.
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Abstract The low permeabilities of unconventional reservoirs such as the Montney Formation require hydraulic fracturing to enhance fluid flow and achieve economic production of hydrocarbons. Efficient hydraulic fracturing operations rely on properly characterizing the controlling factors responsible for fracture complexity, fracture conductivity, and fracture dimensions. Since direct observation of fractures in the subsurface are very challenging, technologies have been developed to help characterize fractures in laboratories. However, the scale of these tools is insufficient to capture the fine detail needed to observe how these hydraulic fractures are interacting with the rock fabric, stress state, or fluid viscosity. Presented here is a laboratory experiment designed to evaluate the effects of rock fabric, stress anisotropies, and fluid viscosities using large boulders of Sulfur Mountain Formation (Montney Formation equivalent). These experiments were designed to simulate subsurface conditions and provide an opportunity to directly examine a scaled fracture face. Four large boulders were collected from outcrop and trimmed to fit inside a large stress frame. A borehole was drilled to facilitate the injection of fluids and generate scaled hydraulic fractures. Experiments tested the effects of different stress states, fluid viscosities, and rock fabric on the growth and geometry of hydraulic fractures. Of these factors, the fabric of the rock was the dominant factor controlling hydraulic fracture growth. In all stress regimes, hydraulic fractures were arrested, deflected, or bridged by pre-existing cemented and open natural fractures. Fluid viscosity had a minor effect on fracture complexity, but no discernable difference could be observed between any of the tested stress regimes. Subsurface core data provided additional data to support the laboratory experiments. Hardness measurements showed that finely laminated facies have variable hardness at the lamination scale. Darker laminations with more clay are softer than the more silt-rich light-coloured laminations. The result of this can be observed in both core and outcrop as natural fractures in these facies often display highly irregular geometries. In addition, fracture filling cement was significantly softer than the surrounding rock. The collective result of both core and laboratory data provides valuable insight into the role of rock fabric in the development of hydraulic fractures in the Montney Formation and that is not obtainable from traditional data collection methods. Résumé La faible perméabilité des réservoirs non conventionnels, tels que la Formation de Montney, nécessite la fracturation hydraulique pour améliorer l’écoulement des fluides et réaliser une production d’hydrocarbures rentables. Pour réaliser des opérations de fracturation efficientes, on doit caractériser proprement les facteurs qui régissent la complexité, la conductivité et la dimension des fractures. Puisque l’observation directe des fractures dans la subsurface reste un défi, des technologies ont été mises au point pour mieux caractériser les fractures en laboratoire. Toutefois, l’étendue de ces outils se révèle insuffisante pour saisir les fins détails nécessaires à l’observation de ces fractures hydrauliques qui interagissent avec la fabrique des roches, l’état de contrainte ou la viscosité des fluides. Le présent document expose une expérience en laboratoire conçue pour évaluer les effets de la fabrique des roches, des anisotropies de contrainte et des viscosités de fluides au moyen de gros blocs rocheux extraits de la Formation de mont Sulphur (équivalente à la Formation de Montney). Ces expériences permettent de simuler les conditions en subsurface et d’examiner directement un plan à l’échelle des fractures. Quatre gros blocs rocheux ont été extraits d’un affleurement puis taillés afin de les disposer dans un grand cadre de contrainte. Puis, un trou de sondage a été foré pour faciliter l’injection de fluides et générer des fractures hydrauliques à l’échelle. L’expérience visait à constater les effets de différents états de contrainte, de différentes viscosités des fluides et fabrique des roches sur la croissance et la géométrie des fractures hydrauliques. Entre tous ces facteurs, la fabrique de la roche était le facteur prédominant régissant la croissance des fractures hydrauliques. Dans tous les régimes de contrainte, les fractures hydrauliques ont été arrêtées, déviées ou pontées par des fractures cimentées préexistantes naturelles et ouvertes. La viscosité des fluides avaient eu un effet mineur sur la complexité des fractures, mais aucune différence discernable n’a pu être observée entre tous les régimes de contrainte testés. Les carottes de sondage de la subsurface ont apporté des données additionnelles pour appuyer les expériences en laboratoire. Le duromètre montrait que les faciès finement laminés présentaient une dureté variable à l’échelle de lamination. Les laminations plus foncées avec plus d’argile se révélaient plus molles que celles plus claires, riches en silt. Nous pouvons observer les résultats de ce qui précède dans les carottes de sondage et les affleurements puisque les fractures naturelles de ces faciès affichent souvent des géométrie fortement irrégulières. De plus, le ciment de remplissage des fractures était notablement plus mou que la roche adjacente. Les résultats collectifs des carottes de sondage et du laboratoire nous fournissent un aperçu précieux dans le rôle de la fabrique des roches dans l’évolution des fractures hydrauliques de la Formation de Montney, que l’on ne pourrait obtenir autrement par des méthodes de collecte de données traditionnelles. Michel Ory
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Al-Sharai, Abdo Ali, Chin Fhong Soon, Chan Hwang See, See Khee Yee, Kian Sek Tee und Mohammed Abdul Wahab. „MODELLING OF CO-AXIAL AND TRI-AXIAL MILLI-FLUIDIC DEVICES FOR CO-EXTRUSION OF SEMI-SOLID SOLIDS“. ASEAN Engineering Journal 13, Nr. 2 (31.05.2023): 93–100. http://dx.doi.org/10.11113/aej.v13.18953.
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With the use of a milli-fluidics device, it is possible to manipulate small amounts of fluid in the millimeter range with pinpoint accuracy. The milli-fluidics are currently lacking in studies of the relationship between fluid viscosity, output velocity and output pressure. Thus, this study examines the effects of viscosity on fluid dynamics in the co-axial and tri-axial milli-fluidics. This geometry of the co-axial and tri-axial milli-fluidics consist of single outlet, two inlets and three inlets, respectively. The tri-axial milli-fluidics is 46 mm long and 11.31 mm wide, while, the coaxial milli-fluidic is 64.73 mm long and 9.2 mm wide. The co-axial milli-fluidics constituted of 775 domain elements and 147 boundary elements, while, the tri-axial milli-fluidics mesh constituted of 1518 domain elements and 178 boundary elements. Laminar flow was observed for the flow of the materials through the channels. When the dynamic viscosity approaches 5 mPa.s, the simulation reveals that the flow rate is inversely proportional to the dynamic viscosity for co-axial milli-fluidics. It was difficult to combine fluids with different viscosities with small volume of water in a narrow boundary, thus the parallel flow of material was observed. When using the one outlet channel for the tri-axial milli-fluidics, the assemble pressure at the three inlets was decreased compared with co-axial milli-fluidic. Even when the dynamic velocity of the fluid at outlet 1 increased, its velocity remained consistent. An extruder using tri-axial milli-fluidics can be used if the interfacial tension for intake 1 is higher than for inlet 2 and the dynamic viscosity of fluid 1 is above 2 mPas, according to the volumetric fraction model. The tri-axial milli-fluidic was found to be suitable for producing cladding of material with the balanced pressure from the two side channels.
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Althobaiti, Nesreen. „Importance of Activation Energy on Magnetized Dissipative Casson-Maxwell Fluid through Porous Medium Incorporating Chemical Reaction, Joule Heating, and Soret Effects: Numerical Study“. Journal of Applied Mathematics 2024 (05.01.2024): 1–14. http://dx.doi.org/10.1155/2024/5730530.
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In recent decades, the study of non-Newtonian fluids has attracted the interest of numerous researchers. Their study is encouraged by the significance of these fluids in fields including industrial implementations. Furthermore, the importance of heat and mass transfer is greatly increased by a variety of scientific and engineering processes, including air conditioning, crop damage, refrigeration, equipment power collectors, and heat exchangers. The key objective of this work is to use the mathematical representation of a chemically reactive Casson-Maxwell fluid over a stretched sheet circumstance. Arrhenius activation energy and aspects of the magnetic field also have a role. In addition, the consequences of both viscous dissipation, Joule heating, and nonlinear thermal radiation are considered. The method transforms partial differential equations originating in fluidic systems into nonlinear differential equation systems with the proper degree of similarity which is subsequently resolved utilizing the Lobatto IIIA technique’s powerful computing capabilities. It is important to recall that the velocity profile drops as the Maxwell fluid parameter increases. Additionally, the increase in the temperature ratio parameter raises both the fluid’s temperature and the corresponding thickness of the boundary layer.
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Fetecau, Constantin, Dumitru Vieru, Lucian Eva und Norina Consuela Forna. „Memory Effects in the Magnetohydrodynamic Axial Symmetric Flows of Oldroyd-B Fluids in a Porous Annular Channel“. Symmetry 16, Nr. 9 (26.08.2024): 1108. http://dx.doi.org/10.3390/sym16091108.
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In this article, we analytically investigate the isothermal magnetohydrodynamic axial symmetric flows of ordinary and fractional incompressible Oldroyd-B fluids through a porous medium in an annular channel. The fluid’s motion is generated by an outer cylinder, which moves along its symmetry axis with an arbitrary time-dependent velocity Vh(t). Closed-form expressions are established for the dimensionless velocity fields of both kinds of fluids, generating exact solutions for any motion of this type. To illustrate the concept, two particular cases are considered, and the velocity fields corresponding to the flow induced by the outer cylinder are presented in simple forms, with the results validated graphically. The motion of fractional and ordinary fluids becomes steady over time, and their corresponding velocities are presented as the sum of their steady and transient components. Moreover, the steady components of these velocities are identical. The influence of magnetic fields and porous media on the flow of fractional fluids is graphically depicted and discussed. It was found that a steady state is reached earlier in the presence of a magnetic field and later in the presence of a porous medium. Moreover, this state is obtained earlier in fractional fluids compared with ordinary fluids.
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Lomba, Rosana F. T., Carlos H. M. de Sa´ und Edimir M. Branda˜o. „A New Approach to Evaluate Temperature Effects on Rheological Behavior of Formate-Based Fluids“. Journal of Energy Resources Technology 124, Nr. 3 (06.08.2002): 141–45. http://dx.doi.org/10.1115/1.1485293.
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Organic salt brines represent a good alternative to drill through deep productive zones. The literature presents these salts as thermal stabilizers of polymers used in the formulation of drill-in fluids. An extensive study was carried out to evaluate the rheological behavior of formate-based fluids as a function of temperature and density. An analytical expression was developed to correlate shear stresses with temperature for general drilling fluids and a special case of this expression results in a greatly simplified expression that is valid for a number of drilling and completion fluids produced using different alkali-metal salts of formic acid. The advantage of this new approach is the lack of dependence between the proposed correlation and the choice of a rheological model. Unlike many expressions presented in the literature, the expression proposed and methodology that follows allows the choice of a best-fit model to predict the fluid’s rheological behavior as a function of temperature. Experimental results show that formates do improve the thermal stability of polymers. The proposed correlations will soon be incorporated in a wellbore cleaning numerical simulator to compensate for thermal effects.
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Fetecau, Constantin, Shehraz Akhtar und Costică Moroşanu. „Porous and Magnetic Effects on Modified Stokes’ Problems for Generalized Burgers’ Fluids“. Dynamics 3, Nr. 4 (01.12.2023): 803–19. http://dx.doi.org/10.3390/dynamics3040044.
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In this paper, exact analytical expressions are derived for dimensionless steady-state solutions corresponding to the modified Stokes’ problems for incompressible generalized Burgers’ fluids, considering the influence of porous and magnetic effects. Actually, these are the first exact solutions for such motions of these fluids. They can easily be particularized to give similar solutions for Newtonian, second-grade, Maxwell, Oldroyd-B and Burgers’ fluids. It is also proven that MHD motion problems of such fluids between infinite parallel plates can be investigated when shear stress is applied at the boundary. To validate the obtained results, the velocity fields are presented in two distinct forms, and their equivalence is proven through graphical representations. The obtained outcomes are utilized to determine the time required to reach a steady state and to elucidate the impacts of porous and magnetic parameters on the fluid motion. This investigation reveals that the attainment of a steady state occurs later when a porous medium or magnetic field is present. Additionally, the fluid’s flow resistance is augmented in the presence of a magnetic field or through a porous medium. Thus, as was expected, the fluid moves slower through porous media or in the presence of a magnetic field.
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Yerin, C. V. „SPECTRAL DEPENDENCIES OF MAGNETOOPTICAL EFFECTS IN MAGNETIC FLUIDS“. Eurasian Physical Technical Journal 19, Nr. 2 (40) (15.06.2022): 86–92. http://dx.doi.org/10.31489/2022no2/86-92.
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The spectral dependences of the transmittance and optical anisotropy effects in magnetic fluid have been investigated. It is shown that the refractive index spectra of bulk magnetite known are of little use for the quantitativeand qualitative interpretation of optical effects in magnetic fluids. The transmission, birefringence, and dichroism spectra are calculated using the known refractive index spectra of magnetite. The best agreement with the experiment was obtained using the experimental spectra of the complex refractive index of the powder of magnetite nanoparticles. It is concluded that there is a significant difference in the spectra of the complex refractive index for bulk and nanosized magnetite.
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Song, Sanggeun, Seong Jun Park, Minjung Kim, Jun Soo Kim, Bong June Sung, Sangyoub Lee, Ji-Hyun Kim und Jaeyoung Sung. „Transport dynamics of complex fluids“. Proceedings of the National Academy of Sciences 116, Nr. 26 (07.06.2019): 12733–42. http://dx.doi.org/10.1073/pnas.1900239116.
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Thermal motion in complex fluids is a complicated stochastic process but ubiquitously exhibits initial ballistic, intermediate subdiffusive, and long-time diffusive motion, unless interrupted. Despite its relevance to numerous dynamical processes of interest in modern science, a unified, quantitative understanding of thermal motion in complex fluids remains a challenging problem. Here, we present a transport equation and its solutions, which yield a unified quantitative explanation of the mean-square displacement (MSD), the non-Gaussian parameter (NGP), and the displacement distribution of complex fluids. In our approach, the environment-coupled diffusion kernel and its time correlation function (TCF) are the essential quantities that determine transport dynamics and characterize mobility fluctuation of complex fluids; their time profiles are directly extractable from a model-free analysis of the MSD and NGP or, with greater computational expense, from the two-point and four-point velocity autocorrelation functions. We construct a general, explicit model of the diffusion kernel, comprising one unbound-mode and multiple bound-mode components, which provides an excellent approximate description of transport dynamics of various complex fluidic systems such as supercooled water, colloidal beads diffusing on lipid tubes, and dense hard disk fluid. We also introduce the concepts of intrinsic disorder and extrinsic disorder that have distinct effects on transport dynamics and different dependencies on temperature and density. This work presents an unexplored direction for quantitative understanding of transport and transport-coupled processes in complex disordered media.
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Alasaly, Hasanaliabbood, und Ibtehal Kareem Shakir. „Enhance the Properties of Lignosulfonate Mud by Adding Nanoparticles of Aluminum Oxide and Iron Oxide“. Iraqi Journal of Chemical and Petroleum Engineering 23, Nr. 4 (30.12.2022): 25–32. http://dx.doi.org/10.31699/ijcpe.2022.4.4.
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Oil well drilling fluid rheology, lubricity, swelling, and fluid loss control are all critical factors to take into account before beginning the hole's construction. Drilling fluids can be made smoother, more cost-effective, and more efficient by investigating and evaluating the effects of various nanoparticles including aluminum oxide (Al2O3) and iron oxide (Fe2O3) on their performance. A drilling fluid's performance can be assessed by comparing its baseline characteristics to those of nanoparticle (NPs) enhanced fluids. It was found that the drilling mud contained NPs in concentrations of 0,0.25, 0. 5, 0.75 and 1 g. According to the results, when drilling fluid was used without NPs, the coefficient of fraction (CoF) was 44%, when added Al2O3 NP and Fe2O3 NP at 0.75g reduced CoF by 31% and 33% respectively. When Al2O3 and Fe2O3 NPs were used, particularly at a concentration of 1g, the amount of mud filtration decreased from 13.5ml to 9.3 ml and 8.5 ml respectively. Additional improvements rheological properties as well as swelling when Fe2O3NPs and Al2O3 NPs were added at 1g. Overall, it was found that adding NPs to the Lignosulfonate-WBM at a concentration of 1g can improve rheological, swelling, and filtration properties as well as lubrication at 0.75g.
Dissertationen zum Thema "Effets fluides"
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Mohamad, Sawsan. „Effets de taille sur des membranes fluides d'étendue finie“. Phd thesis, Université du Maine, 2011. http://tel.archives-ouvertes.fr/tel-00658790.
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La technique de microscopie SEEC (Surface Enhanced Ellipsometric Contrast) permet l'observation directe de couches moléculaires. Notre objectif global est d'exploiter cette possibilité pour étudier la structure d'équilibre de domaines amphiphiles d'épaisseur nanométrique et d'étendue finie (quelques microns) déposés sur une surface solide. Ces domaines subissent une pression de Laplace importante, qui dépend de leur rayon R comme 1/R. Cette pression agit sur ces systèmes 2D comme une contrainte externe qu'on peut moduler en faisant varier la taille des domaines. La mesure de leur épaisseur en fonction de leur taille est donc une façon d'explorer les isothermes de ces systèmes, ce qui est le pendant pour des systèmes supportés des études effectuées au moyen d'une cuve de Langmuir sur les monocouches à la surface de l'eau. Idéalement, ces domaines se réduisent à une simple monoou bicouche. En pratique, ils adoptent souvent la forme de ziggourats constitués de plusieurs étages (gouttes terrassées). Le travail présenté dans cette thèse est une première étape dans la démarche évoquée ci-dessus. Il a permis de mettre en évidence pour la première fois les effets de la tension de Laplace sur la structure de domaines bicouches. L'étude est réalisée à l'aide de molécules amphiphiles de natures très différentes : 1) des copolymères à blocs symétriques, 2) des phospholipides. Elle exige la maîtrise du dépôt, de l'environnement et de l'évolution de nano-gouttes smectiques sur une surface, et le développement d'outils d'analyse adaptés. Elle implique principalement deux techniques : la Microscopie à Force Atomique (AFM) et la microscopie optique en contraste SEEC.
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Bour, Olivier. „Transferts de fluides dans les milieux fracturés : Effets d'echelle“. Phd thesis, Université Rennes 1, 1996. http://tel.archives-ouvertes.fr/tel-00619329.
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A la suite d'une demande de divers secteurs en développement, comme !'-enfouissement des déchets (nucléaires, industriels et ménagers), et l'amélioration des ressources géothermiques, pétrolières ou en eau souterraine, la recherche sur les circulations de fluides dans les milieux fracturés a connu un essor croissant ces dernières années. Malheureusement, la modélisation des écoulements dans ces milieux se heurte à la complexité géométrique des champs de failles qui présentent une large gamme de longueurs et d'ouvertures, ainsi qu'une distribution spatiale non-homogène. La superposition de ces paramètres géométriques conduit en particulier à des effets d'échelles sur les coefficients de transport qui restent encore mal définis. Après avoir entrepris une analyse statistique bi-dimensionnelle de la géométrie de plusieurs réseaux de failles naturels, nous avons développé une approche fondée sur la théorie de la percolation, dans le but de déterminer les principaux paramètres géométriques gouvernant les propriétés de transport des milieux fracturés. La description géométrique d'une faille nécessite au moins trois paramètres géométriques, que l'on peut supposer a priori indépendants : sa position dans l'espace, sa longueur et son orientation. Pourtant, en analysant séparément leurs distributions spatiales nous avons montré qu'entre les différents paramètres géométriques, il existe des corrélations nettes qui résultent probablement des interactions mécaniques inteNenant lors de la croissance des champs de failles. En particulier, nos résultats suggèrent l'existence d'une relation entre la dimension fractale des barycentres de failles et l'exposant de la loi d'échelle de la distribution des longueurs de failles. L'adaptation de la théorie de la percolation à la géométrie spécifique des milieux fracturés en général, et à leur très large distribution de longueurs, en particulier, a permis de décrire leurs propriétés de connectivité. Cette analyse théorique a pu être vérifiée en deux et trois dimensions, grâce à un .modèle numérique. Les implications de cette analyse reposent en grande partie sur une quantification du rôle des "grandes" et des "petites" failles, qui permet de définir l'obseNable pertinent. La géométrie des chemins de connection (amas percolant) et des chemins d'écoulement (backbone) au seuil de percolation est décrite sous la forme de lois d'échelles. Il est également montré comment certaines distributions de longueurs, fréquentes dans la nature, impliquent nécessairement l'existence d'une échelle au-dessus de laquelle les réseaux de failles sont bien connectés (longueur de corrélation finie). L'application de notre analyse à plusieurs réseaux de failles naturels a permis de montrer l'adéquation de l'approche théorique développée. Ce travail définit un cadre théorique qui permettra de fournir les bases d'une modélisation originale des propriétés de transport des systèmes fracturés. Cette proposition de modèle s'appuie à la fois sur l'éventuelle dépendance d'échelle des coefficients de transport, qui a par ailleurs été obseNée grâce à une étude expérimentale menée sur le site de Ploemeur (Morbihan), et sur l'utilisation de distributions géométriques appropriées aux systèmes fracturés.
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Bour, Olivier. „Transferts de fluides dans les milieux fractures : effets d'echelle“. Rennes 1, 1996. http://www.theses.fr/1996REN10112.
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La modelisation des ecoulements de fluides dans les milieux fractures se heurte a la complexite geometrique des reseaux de failles dont les effets d'echelle sont encore mal maitrises. Afin de determiner les implications de la geometrie des reseaux de failles sur les proprietes d'ecoulement, nous avons developpe une approche basee sur la theorie de la percolation. Cette approche a necessite: i) la caracterisation geometrique des reseaux de failles a l'aide de distributions statistiques ; ii) la determination des principaux parametres gouvernant les proprietes de connectivite des milieux fractures ; iii) la confrontation de nos resultats au milieu naturel. Nos resultats montrent que la distribution spatiale des positions de failles est fractale. En revanche, la distribution spatiale des traces de failles est uniforme. Nous montrons egalement qu'il existe des correlations entre les differents parametres geometriques (position, longueur). L'adaptation de la theorie de la percolation a la geometrie des milieux fractures a permis de decrire leurs proprietes de connectivite. Cette analyse theorique a pu etre verifiee en 2 et 3 dimensions a l'aide d'un modele numerique. La geometrie de l'amas percolant et du backbone au seuil de percolation sont decrites. Il est notamment montre comment certaines distributions de longueurs, frequentes dans la nature, impliquent necessairement une longueur de correlation finie des systemes fractures. Ce travail jette les bases d'une modelisation originale des proprietes de transport des systemes fractures a l'aide d'un modele conceptuel baptise milieu heterogene equivalent. Il s'appuie a la fois sur la dependance eventuelle des coefficients de transport avec l'echelle de mesure qui a, par ailleurs, ete observee grace a une etude experimentale et sur l'utilisation de distributions geometriques appropriees aux systemes fractures
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Mohamad, Sawsan. „Effets de taille sur des membranes fluides d’étendue finie“. Thesis, Le Mans, 2011. http://www.theses.fr/2011LEMA1013/document.
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La technique de microscopie SEEC (Surface Enhanced Ellipsometric Contrast) permet l’observation directe de couches moléculaires. Notre objectif global est d’exploiter cette possibilité pour étudier la structure d’équilibre de domaines amphiphiles d’épaisseur nanométrique et d’étendue finie (quelques microns) déposés sur une surface solide. Ces domaines subissent une pression de Laplace importante, qui dépend de leur rayon R comme 1/R. Cette pression agit sur ces systèmes 2D comme une contrainte externe qu’on peut moduler en faisant varier la taille des domaines. La mesure de leur épaisseur en fonction de leur taille est donc une façon d’explorer les isothermes de ces systèmes, ce qui est le pendant pour des systèmes supportés des études effectuées au moyen d’une cuve de Langmuir sur les monocouches à la surface de l’eau. Idéalement, ces domaines se réduisent à une simple monoou bicouche. En pratique, ils adoptent souvent la forme de ziggourats constitués de plusieurs étages (gouttes terrassées). Le travail présenté dans cette thèse est une première étape dans la démarche évoquée ci-dessus. Il a permis de mettre en évidence pour la première fois les effets de la tension de Laplace sur la structure de domaines bicouches. L’étude est réalisée à l’aide de molécules amphiphiles de natures très différentes : 1) des copolymères à blocs symétriques, 2) des phospholipides. Elle exige la maîtrise du dépôt, de l’environnement et de l’évolution de nano-gouttes smectiques sur une surface, et le développement d’outils d’analyse adaptés. Elle implique principalement deux techniques : la Microscopie à Force Atomique (AFM) et la microscopie optique en contraste SEECLa technique de microscopie SEEC (Surface Enhanced Ellipsometric Contrast) permet l’observation directe de couches moléculaires. Notre objectif global est d’exploiter cette possibilité pour étudier la structure d’équilibre de domaines amphiphiles d’épaisseur nanométrique et d’étendue finie (quelques microns) déposés sur une surface solide. Ces domaines subissent une pression de Laplace importante, qui dépend de leur rayon R comme 1/R. Cette pression agit sur ces systèmes 2D comme une contrainte externe qu’on peut moduler en faisant varier la taille des domaines. La mesure de leur épaisseur en fonction de leur taille est donc une façon d’explorer les isothermes de ces systèmes, ce qui est le pendant pour des systèmes supportés des études effectuées au moyen d’une cuve de Langmuir sur les monocouches à la surface de l’eau. Idéalement, ces domaines se réduisent à une simple monoou bicouche. En pratique, ils adoptent souvent la forme de ziggourats constitués de plusieurs étages (gouttes terrassées). Le travail présenté dans cette thèse est une première étape dans la démarche évoquée ci-dessus. Il a permis de mettre en évidence pour la première fois les effets de la tension de Laplace sur la structure de domaines bicouches. L’étude est réalisée à l’aide de molécules amphiphiles de natures très différentes : 1) des copolymères à blocs symétriques, 2) des phospholipides. Elle exige la maîtrise du dépôt, de l’environnement et de l’évolution de nano-gouttes smectiques sur une surface, et le développement d’outils d’analyse adaptés. Elle implique principalement deux techniques : la Microscopie à Force Atomique (AFM) et la microscopie optique en contraste SEEC
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Bour, Olivier. „Transferts de fluides dans les milieux fracturés : effets d'échelle /“. Rennes : Géosciences, Université de Rennes I, 1997. http://catalogue.bnf.fr/ark:/12148/cb36193356d.
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Hallez, Yannick. „Mélange gravitationnel de fluides en géométrie confinée“. Phd thesis, Toulouse, INPT, 2007. http://oatao.univ-toulouse.fr/7616/1/hallez.pdf.
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Ce travail basé sur la simulation numérique directe porte sur le mélange en géométrie confinée de deux fluides miscibles de densités différentes. Le mouvement des fluides est induit par la gravité. Différentes géométries sont étudiées : un tube cylindrique, un canal de section carrée et un écoulement purement bidimensionnel. Les simulations numériques confirment pleinement les résultats expérimentaux de Séon et al. en tube cylindrique, avec notamment la mise en évidence de trois régimes différents suivant l’inclinaison du tube. La comparaison des géométries montre que les écoulements tridimensionnels en tube et en canal inclinés présentent des comportements similaires tandis que le « modèle » bidimensionnel est incapable de donner des informations pertinentes sur un écoulement réel tridimensionnel tant au niveau quantitatif qu’au niveau phénoménologique. Une attention particulière est portée à l’analyse conjointe du champ de concentration et de la dynamique tourbillonnaire sous-jacente qui permet d’expliquer plusieurs aspects subtils de la dynamique du mélange.
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Masselon, Chloé. „Effets non locaux dans un écoulement microfluidique de micelles géantes“. Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13635/document.
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L’étude des fluides complexes présente un grand intérêt de par la richesse des phénomènes que font intervenir leur écoulement. Une étude de rhéologie locale de systèmes de micelles géantes en microcanal droit est effectuée. L’expérience montre que les propriétés du fluide soumis à un fort gradient de contrainte ne peuvent être décrites que par une équation rhéologique comportant des termes non locaux. Nous montrons alors l’influence du système de micelles géantes, du confinement ainsi que de la nature des surfaces du microcanal sur ces effets non locaux. Une étude des phénomènes temporels intervenant dans ces écoulements en microcanaux est alors proposée, ainsi qu’une étude préliminaire concernant les écoulements dans des milieux poreux modèlesThe study of complex fluids flows is of great interest according to the diversity of phenomenon it involves. A study of the local rheology of wormlike micelles flowing in a simple straight microchannel is proposed. Experiments show that the properties of such a fluid undergoing a strong shear stress gradient can only be described by an equation including non local terms. We thereafter show the influence of the wormlike micelles system, of the confinement and of the nature of the microchannel walls on those non local effects. A study of the temporal phenomenon occurring in microfluidic flows of wormlike micelles is then proposed, as well as a preliminary study concerning flows in porous media
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Khodja, Mohamed. „Les fluides de forage : étude des performances et considérations environnementales“. Phd thesis, Toulouse, INPT, 2008. http://oatao.univ-toulouse.fr/7728/1/khodja.pdf.
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Lors des forages pétroliers, la traversée des formations argileuses pose des problèmes dont la résolution est étroitement liée à la compréhension des interactions argile - fluide de forage. Vu les imperfections des fluides à base d'eau (WBM) face aux problèmes des argiles, les systèmes de fluides émulsionnés à base d'huile (OBM) ont apporté des améliorations significatives. Cependant, la pollution qu’ils engendrent rend indispensable un traitement des boues usagées. Au cours de ce travail, nous avons voulu confronter le maximum de données de laboratoire à des données effectives de chantier et ce, dans l’espoir d’apporter une contribution à la résolution des problèmes réels. Trois systèmes modèles de fluides du type WBM on été sélectionnés : ils contiennent, en plus des polymères conventionnels (xanthane et cellulose polyanionique), des inhibiteurs de gonflement et de dispersion des argiles (polyacrylamide partiellement hydrolysé, silicates de sodium, polyalkylèneglycols). La comparaison de leurs perfo rmances, grâce à l'utilisation d'une nouvelle méthode basée sur la filtration sur pastilles compactées, a été discutée : - du point de vue macroscopique par l'analyse de leurs caractéristiques rhéologiques et de filtration, le suivi des interactions argile -fluide par l'étude des propriétés électrocinétiques, granulométriques et de rétention des polymères, - et à l'échelle microscopique par diffraction X in -situ (wet cell) et par diffraction de la lumière. Les caractéristiques rhéologiques et de filtration ont été corrélées aux propriétés électrocinétiques et complétées par l'étude des propriétés interfaciales et de mouillage. Le système aux silicates présente les meilleures performances en termes d'inhibition. L'étude de la stabilité des systèmes émulsionnés (OBM) a porté sur l'influence du type et de la concentration des tensioactifs, de la proportion de phase dispersée et de la présence d’autres additifs. La concentration optimale est celle donnant un compromis entre une stabilité électrique acceptable, un p ourcentage d’émulsion élevé et une meilleure résistance à la centrifugation. Le suivi de la variation de la phase émulsionnée, de la stabilité électrique et de la distribution granulométrique a permis de classer les différents émulsifiants. Parallèlement aux mesures rhéologiques, l'analyse des structures formées (émulsion-argile organophile) par diffusion des neutrons aux petits angles (SANS) a permis d'expliquer les mécanismes de stabilisation. Une nouvelle formulation d'émulsifiants, proposée pour un essa i sur chantier, a donné des résultats encourageants par rapport aux formulations commerciales. Au niveau du réservoir, l’impact des fluides de forage est appréhendé par l’étude des processus d’endommagement de la roche. Un de nos objectifs était de corrél er les résultats globaux obtenus pour la formulation complète avec l'endommagement induit par les additifs seuls. Les essais réalisés ont montré l'influence de la nature, de la composition chimique, et de la granulométrie des additifs. Vu la complexité des phénomènes mis en jeu, la prévision de l'endommagement par une tentative de modélisation a décelé des liens entre les propriétés des fluides utilisés, les caractéristiques de la roche et l'importance de l'endommagement induit. La filtration statique favor ise la formation du "cake" alors que la filtration dynamique contribue à l'invasion du filtrat. Sur le plan environnemental, en plus des pertes de circulation des fluides pendant et après le forage, le bourbier, en tant que collecteur des produits liquide s et solides issus du forage, représente une grande source de pollution et de danger. Le diagnostic des techniques de traitement utilisées a montré des imperfections majeures pouvant induire des nuisances pour la santé humaine, l'écosystème et l'environnement. Le présent travail s’est focalisé sur quelques éléments de réponse à l'équation performance -coûtenvironnement, en proposant un traitement biologique.
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Géraud, Baudouin. „Mouillage et dynamique confinée de fluides complexes“. Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10170.
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Les fluides complexes tels que les gels, les pâtes ou les émulsions présentent une large gamme d'applications, tant dans la vie quotidienne que dans l'industrie. Parmi ces fluides, les fluides dits ”à seuil” se comportent soit comme des solides élastiques, soit comme des fluides nonnewtoniens selon la contrainte qu'on leur applique. Ces propriétés sont décrites par des lois phénoménologiques (telle que la loi d'Herschel Bulkley), bien que leurs origines soient encore mal comprises. Dans cette thèse, nous nous intéressons à la question des petites échelles, où la structure et les phénomènes interfaciaux jouent des rôles prépondérants dans les écoulements. Ce travail expérimental a été essentiellement mené sur du carbopol, un microgel de polymères et un fluide à seuil modèle. L'étude se concentre essentiellement sur trois points : – La caractérisation rhéologique et structurale des échantillons. L'accent est porté sur l'influence du protocole de préparation sur les propriétés des gels.– Le cas des écoulements confinés de fluides complexes. Ce travail met en évidence l'existence d'effets non-locaux aux échelles micrométriques, faisant intervenir une taille caractéristique interprétée dans le cadre du modèle de fluidité. – Les ascensions capillaires de fluides complexes, aux échelles millimétriques. En revisitant l'expérience classique des ascensions capillaires dans le cas des fluides complexes, cette étude propose une extension de la loi de Jurin au cas des fluides à seuil. Il est montré que cette expérience simple permet de mesurer la tension de surface et quelques paramètres rhéologiques de fluides complexes tels que le seuil et l'exposant d'Herschel-BulkleyComplex fluids such as gels, pastes or emulsions have a wide range of applications, both in everyday life and in the industry. Among them, Yield Stress Fluids (YSF) behave either as solids or as non-Newtonian fluids depending on the shear stress applied. These features are modeled by phenomenological laws ( such as the Herschel-Bulkley one ) although their origins are still poorly understood. In this thesis, we focus on the issue of small lengthscales where the structure and interfacial phenomena play predominant roles in the flows. This experimental work was essentially carried out on carbopol, a polymer microgel and a model YSF. The study mainly focuses on three points : – The rheological and structural characterization of the samples. The emphasis is put on the influence of the preparation protocol on the microgel properties. – The case of confined flows of complex fluids. This work highlights the existence of nonlocal effects at the micrometer scales, involving a characteristic length, interpreted in the frame of the fluidity model. – Capillary ascents of complex fluids, involving millimeter scales. This work suggests an extension of Jurin’s law to the case of YSFs. It is shown that this simple experiment allows to measure the surface tension and some rheological parameters of complex fluids such as the yield stress and the Herschel-Bulkley exponent
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Huber, Grégory. „Modélisation des effets d'interpénétration entre fluides au travers d'une interface instable“. Phd thesis, Aix-Marseille Université, 2012. http://tel.archives-ouvertes.fr/tel-00833037.
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Les explosions sphériques entraînent des perturbations importantes de l'interface entre les produits de détonation et l'air. Ces instabilités jouent un rôle dominant dans la détermination du volume de la "boule de feu". Un calcul sphérique unidimensionnel classique conduit un volume de sphère très inférieur à celui mesuré expérimentalement. De plus, des réactions de post-combustion peuvent avoir lieu dans la zone de mélange, libérant une énergie deux fois supérieur à celle de la détonation, déjà considérable. À une échelle suffisamment petite, on distingue les longueurs d'onde des instabilités et les tailles de jets, mais à une échelle plus globale, on observe une couche de mélange où la forme précise de l'interface n'est plus visible. Les deux phases (produits détonation et de l'air) s'interpénètrent, et par conséquent, l'interface devient une zone de mélange. Pour calculer correctement chacune des instabilités, une approche multidimensionnelle semble s'imposer. Cependant, un grand nombre de cellules est nécessaire pour calculer une structure unique de la zone de mélange. En outre, pour une instabilité isolé, le maillage entraînent des instabilités parasites qui dépendent fortement de la viscosité numérique du schéma utilisé. L'approche multidimensionnelle, basée sur la simulation numérique directe, présente donc des difficultés. En réalité, nous ne voulons pas calculer la forme exacte des instabilités de l'interface, mais seulement l'épaisseur de la couche de mélange et les champs de concentrations des phases dans celle-ci. Ainsi, une approche unidimensionnelle peut être suffisante. L'objectif est d'écrire un modèle unidimensionnel décrivant le phénomène d'interpénétration. Trois modèles ont alors été construits à partir du modèle diphasique de l'Baer et Nunziato (1986). Nous obtenons des résultats intéressants avec les deux premiers sur des problématiques d'épaississement d'interface, mais ils sont insuffisants. Le dernier modèle, qui dérive des deux premiers, a été validé sur des tests d'explosions sphériques.
Bücher zum Thema "Effets fluides"
1
Andrés, Negro-Vilar, und Conn P. Michael, Hrsg. Peptide hormones: Effects and mechanisms of action. Boca Raton, Fla: CRC Press, 1988.
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2
L, Ash Robert, und United States. National Aeronautics and Space Administration., Hrsg. Viscous effects on a vortex wake in ground effect. Norfolk, Va: Old Dominion University Research Foundation, Dept. of Mechanical Engineering & Mechanics, College of Engineering & Technology, Old Dominion University, 1992.
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Carroll, Michael M., und Michael A. Hayes, Hrsg. Nonlinear Effects in Fluids and Solids. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-0329-9.
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M, Carroll Michael, und Hayes M. A, Hrsg. Nonlinear effects in fluids and solids. New York: Plenum Press, 1996.
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Totten, GE, DK Wills und DG Feldmann, Hrsg. Hydraulic Failure Analysis: Fluids, Components, and System Effects. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2001. http://dx.doi.org/10.1520/stp1339-eb.
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Zappoli, Bernard, Daniel Beysens und Yves Garrabos. Heat Transfers and Related Effects in Supercritical Fluids. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9187-8.
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Hilibrand, Alan Sander. The effects of hydration fluids during prolonged exercise. [New Haven: s.n.], 1990.
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Weitsman, Y. Jack. Fluid Effects in Polymers and Polymeric Composites. Boston, MA: Springer US, 2012. http://dx.doi.org/10.1007/978-1-4614-1059-1.
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Tse, Kathryn Louise. Bubble coalescence in a range of fluids: Surface and viscous effects. Birmingham: University of Birmingham, 2000.
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Baines, Peter G. Topographic effects in stratified flows. Cambridge: Cambridge University Press, 1995.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "Effets fluides"
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Malbrain, Manu L. N. G., Adrian Wong, Luca Malbrain, Prashant Nasa und Jonny Wilkinson. „Terms and Definitions of Fluid Therapy“. In Rational Use of Intravenous Fluids in Critically Ill Patients, 3–46. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42205-8_1.
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AbstractThe book “Rational Fluid Therapy” aims to provide guidance on the appropriate use of intravenous (IV) fluids, which are often overlooked as medications despite being a cornerstone of patient care. In this introductory chapter, the importance of seeing IV fluids as drugs with indications, contra-indications, and potential adverse effects is emphasized. Inappropriate fluid therapy can have deleterious effects and cause patient morbidity and mortality. Therefore, the need for careful oversight and guidance is stressed in fluid prescription, as well as the implementation of fluid stewardship and organ function monitoring. Different terms related to fluid therapy, such as fluid overload and hypervolemia, are often used interchangeably despite indicating different clinical situations. Clear definitions are provided for these terms to avoid misunderstandings and misinterpretations that may lead to inappropriate therapeutic decisions. These definitions will be repeated throughout the book to ensure clarity and consistency.
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Takabe, Hideaki. „Basic Properties of Plasma in Fluid Model“. In Springer Series in Plasma Science and Technology, 15–97. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-45473-8_2.
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AbstractIf the spatial variation of plasma is longer than the particle mean free path and the time variation is sufficiently longer than the plasma Coulomb collision time, the plasma can be approximated as being in local thermal equilibrium (LTE) at any point (t, r). Then the velocity distribution functions of the particles become Maxwellian. In addition, assuming Maxwellian is also a good assumption in many cases even for collisionless plasmas such as high-temperature fusion plasmas. In the fluid model of plasmas, The plasmas can be described in terms of five variables characterizing local Maxwellian: the density n(t, r), flow velocity vector u(t,r), and temperature T(t, r). So, the mathematics used in fluid physics is widely applicable to studying plasma phenomena.Although conventional fluids are neutral, plasma fluids of electrons and ions couple with electromagnetic fields. It is, therefore, necessary to solve Maxwell’s equations simultaneously. It is also possible to approximate electrons and ions as two different fluids or as a single fluid in case-by-case. This requires an insight into what kind of physics is important in our problem.After reviewing the basic equation of fluids, several fluid models for plasmas are shown. Especially, a variety of waves appears because of charged particle fluids are derived to know why waves are fundamental to knowing the plasma dynamics. The mathematical method to obtain the wave solutions as an initial value problem is explained as well as the meaning of the resultant dispersion relations.Magneto-hydrodynamic equations (MHD) are derived to explain the effects of the Biermann battery, magnetic dynamo, etc. The relationship of magnetic field and vortex flow is studied. Resistive MHD is derived including the Nernst effect, which becomes important for the magnetic field in strong electron heat flux.Finally, electromagnetic (EM) waves in magnetized plasmas are derived to see how to use for diagnostics in the laboratory and observation of wide range of electromagnetic waves from the Universe.
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Hamilton, Mark F., und Christopher L. Morfey. „Model Equations“. In Nonlinear Acoustics, 39–61. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-58963-8_3.
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AbstractThe chapter begins with the full equations of fluid mechanics for viscous, heat conducting, homogeneous fluids. Exact implicit solutions are developed for plane waves in ideal fluids, as well as an exact nonlinear wave equation for nonplanar waves in a perfect gas. Ordering procedures are introduced that permit structured derivations of approximate wave equations accounting for quadratic nonlinearity in thermoviscous fluids. A second-order wave equation that includes both cumulative and local nonlinear effects is derived, from which are obtained the Westervelt, Burgers, and KZK equations, and a generalized Burgers equation for cylindrical and spherical waves and waves in horns.
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Choudhuri, Anirban Hom, und Kiranlata Kiro. „Perioperative Fluid Manangement“. In Rational Use of Intravenous Fluids in Critically Ill Patients, 363–78. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42205-8_18.
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AbstractA perioperative clinician should have in-depth knowledge about the composition of body fluids, effects of metabolic stress response on fluid shifts and the indications for timely de-resuscitation. Over the years, the principles of perioperative fluid management have largely focussed on aggressive fluid administration without checks thereby ignoring many harmful side effects. To achieve a good surgical outcome, fluid therapy based on checks and balances is an absolute necessity. Overzealous administration of large volumes of any fluid can lead to more harm than benefit. Hence, the current practice is to individualize the fluid therapy based upon need which can be assessed dynamically by a large number of gadgets. While research about liberal versus restrictive approaches has often yielded divergent results, the benefits of a goal-directed therapy has remained equivocal. The type and duration of the surgery largely influence fluid balance and their understanding is pivotal towards patient safety.
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Wong, Adrian, Jonny Wilkinson, Prashant Nasa, Luca Malbrain und Manu L. N. G. Malbrain. „Introduction to Fluid Stewardship“. In Rational Use of Intravenous Fluids in Critically Ill Patients, 545–65. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42205-8_27.
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AbstractIntravenous (IV) fluids are commonly prescribed drugs in healthcare. However, inappropriate fluid administration is associated with higher morbidity and mortality. Fluid stewardship is defined as a series of coordinated interventions for judicious IV fluid administration, with a primary goal of limiting the deleterious effects of inappropriate fluid prescription and fluid overload or accumulation and optimizing the clinical outcomes. The success of Stewardships in healthcare can achieve success by strategy and policy development, designing overarching systems, encouraging collaboration and ensuring robust governance and accountability processes. The components of fluid stewardship are optimum fluid prescription (5Ps of the fluid prescription), comprehensive fluid guidelines, continuous staff education and an audit or quality improvement framework. The optimum fluid prescription includes the 6 D’s (definitions, diagnosis, drug, dose, duration, de-escalation and documentation at discharge) of IV fluid administration.
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Singh, Ajeet, und Shrikanth Srinivasan. „Understanding Heart-Lung Interactions: Concepts of Fluid Responsiveness“. In Rational Use of Intravenous Fluids in Critically Ill Patients, 113–38. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42205-8_5.
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AbstractThis chapter focuses on the impact of fluid administration and ventilation on hemodynamics in critically ill patients. The chapter emphasizes the importance of determining fluid responsiveness before administering fluids to avoid volume overload, which can lead to increased morbidity and mortality. The parameters for predicting fluid responsiveness are based on cyclic variations in respiration on cardiac filling and require an understanding of heart-lung interactions. The chapter discusses the basics of respiratory and cardio-circulatory physiology, including the two components of the cardiovascular system (the circuit and pump), and how they are affected by transmural pressure. It will discuss the different functional hemodynamic monitoring tools with their indications and pitfalls. A thorough understanding of the effects of spontaneous and positive pressure ventilation on the cardiovascular system is important for anticipating and predicting hemodynamic effects after fluid administration and developing strategies to avoid or treat fluid infusion-related complications.
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Rangasamy, Nithin, Roan Kirwin und C. S. Rakurty. „A Comparative Sustainability Assessment of Cutting Fluids Usage in Band Sawing“. In Lecture Notes in Mechanical Engineering, 21–29. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28839-5_3.
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AbstractCutting fluids used in machining have received a lot of attention due to their adverse environmental and economic effects. Researchers have studied cutting fluid usage in traditional machining processes such as turning, facing, milling, etc. However, few studies focused on the cutting fluid used in band sawing applications. This study reports a literature review of the usage of the cutting fluid in band sawing and their sustainable and economic aspects. A review of the literature and industrial data has shown that the majority of band saw blades use high-speed steel as the cutting tool material for cutting metal. This study presents a metric-based sustainability assessment and a detailed analysis of recent economic factors such as the cost of the cutting fluids used in band sawing through industrial case studies. A global survey of the cutting fluid usage in the bandsawing application has shown that the majority of the industry is employing flood coolant application. The flood coolant application cost can be as high as 8% of the total consumables cost of the band sawing process.
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Singh, Amandeep, und Aayush Chawla. „The Place of Crystalloids“. In Rational Use of Intravenous Fluids in Critically Ill Patients, 205–26. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-42205-8_9.
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AbstractCrystalloids are commonly used in medicine as solutions containing electrolytes dissolved in water, with or without glucose. They can be used as maintenance, replacement, or resuscitation fluids, but should be administered with caution. This chapter provides an overview of basic definitions, terminology, and concepts regarding crystalloids, including their categorization by tonicity, their balanced or unbalanced nature, and the importance of strong ion difference (SID). Improper administration of crystalloids can lead to morbidity, particularly hyperchloremic metabolic acidosis (HMA) and fluid overload. Moreover, saline with a SID of zero can cause a positive sodium balance and subsequent fluid accumulation, which can lead to renal dysfunction and the need for vasopressors and renal replacement therapy. Recent systematic reviews and post-hoc analyses of six major fluid trials have shown that balanced solutions (not containing glucose) reduce mortality by 1%, making them a good first choice for resuscitation in patients with sepsis and septic shock, burns, or diabetic ketoacidosis. Traumatic brain injury and gastrointestinal losses may be the only indications left for (ab)normal saline. The pediatric community still favors isotonic solutions for maintenance, although a growing body of evidence supports hypotonic crystalloids as a better choice. Hypertonic crystalloids have been described for small volume resuscitation in specific patient populations, such as post cardiac arrest, but their sodium burden may outweigh the temporarily beneficial hemodynamic effects. In case of excessive losses, fluids should be substituted or replaced by those that mimic the fluids that are lost, such as blood. Prescribing crystalloid solutions should be done with care. Fluid overload or accumulation and HMA should be avoided, as it can induce extra morbidity and mortality. Choosing the right fluid, indication, dose, and duration is crucial for preventing morbidity and mortality: it is all about giving the right dose of the right fluid at the right time for the right patient!
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Friedman, Avner. „Nonlinear effects in electrorheological fluids“. In Mathematics in Industrial Problems, 115–28. New York, NY: Springer New York, 1998. http://dx.doi.org/10.1007/978-1-4612-1730-5_11.
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Reader-Harris, Michael. „Installation Effects“. In Experimental Fluid Mechanics, 245–80. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-16880-7_8.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "Effets fluides"
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Liao, Quanwen, Zhichun Liu und Wei Liu. „THE THERMAL CONDUCTIVITY OF POLYMERS DEPENDING ON COMBINED EFFECTS OF HYDROGEN BOND AND STRETCHING EFFECT“. In Second Thermal and Fluids Engineering Conference. Connecticut: Begellhouse, 2017. http://dx.doi.org/10.1615/tfec2017.mnt.017433.
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Holtmann, F., M. Woerdemann, J. Imbrock und C. Denz. „Micro-fluidic Velocimetry by Photorefractive Novelty Filtering“. In Photorefractive Effects, Photosensitivity, Fiber Gratings, Photonic Materials and More. Washington, D.C.: OSA, 2007. http://dx.doi.org/10.1364/pr.2007.sud3.
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Meller, Michael A., Matthew J. Bryant und Ephrahim Garcia. „Energetic and Dynamic Effects of Operating Fluid on Fluidic Artificial Muscle Actuators“. In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3210.
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Pneumatic artificial muscles (PAMs) are a relatively common type of lightweight, fluid power actuation. Some disadvantages of PAMs include the compressibility of the working fluid and low damping. These characteristics result in low efficiencies, poor dynamic response, as well as undesired oscillations of the actuators. This paper presents utilizing hydraulic liquid as the working fluid instead of compressed air. Hydraulic operation resulted in almost triple the efficiency of pneumatic operation. The artificial muscles are experimentally characterized both quasi-statically and dynamically. The quasi-static experiments include the tension-strain relationship as a function of pressure, and an actuator net work efficiency analysis. The dynamic tests consist of a free vibration experiment to determine the change in effective spring constant and damping terms. These experiments are conducted for both PAMs and HAMs (hydraulic artificial muscles), and the results are presented herein.
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Georges, Marc P., Luc Joannes, Cedric Thizy, Frank Dubois, Olivier Dupont, Philippe C. Lemaire und Jean-Claude Legros. „Holographic camera with BSO applied to microgravity fluid experiment aboard ISS“. In Photorefractive Effects, Materials, and Devices. Washington, D.C.: OSA, 2001. http://dx.doi.org/10.1364/pemd.2001.18.
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GORODKIN, S., R. JAMES und W. KORDONSKI. „IRREVERSIBLE EFFECTS IN MAGNETORHEOLOGICAL FLUIDS“. In Proceedings of the 12th International Conference. WORLD SCIENTIFIC, 2011. http://dx.doi.org/10.1142/9789814340236_0065.
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Liberman, V., M. Rothschild, S. T. Palmacci, P. A. Zimmerman und A. Grenville. „Laser durability studies of high index immersion fluids: fluid degradation and optics contamination effects“. In Advanced Lithography, herausgegeben von Donis G. Flagello. SPIE, 2007. http://dx.doi.org/10.1117/12.723958.
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Siginer, Dennis A., und Thomas E. Jacks. „Thermocapillary Convection of Viscoinelastic Fluids in Layered Fluid Systems“. In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0490.
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Abstract The flow dynamics of a finite two layered fluid system driven by thermocapillary effects when heated from the side is studied in the absence of gravity. The configuration is of low aspect ratio with a third dimension several orders of magnitude larger. The case of a low Prandtl number Newtonian fluid in the bottom layer encapsulated by a high Prandtl number viscoinelastic fluid with a shear rate and temperature dependent viscosity in the top layer is investigated numerically using the method of finite volumes together with the case of a high Prandtl number viscoinelastic fluid encapsulating another high Prandtl number viscoinelastic fluid in the lower layer both when the top surface is free and a no-slip solid cover. In either case, the top surface is considered to be insulated together with the bottom and viscous dissipation is taken into account. Free surface and interface deformations are neglected. The results are reported for both high and low Marangoni numbers. Appropriate values of the ratio of the interfacial Marangoni number to the free surface Marangoni number are determined to bring the convective motion in the lower layer to a virtual halt.
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Johnson, John, und Andrew K. Wojtanowicz. „Experimental Assessment of Drilling Fluid and Wall Slippage for Wellbore Displacement“. In ASME 2024 43rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2024. http://dx.doi.org/10.1115/omae2024-129807.
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Abstract In the ideal plug-flow mode Bingham-type drilling fluids display strong frontal displacement potential at a very low flowrate. The rate may be significantly increased with the fluid’s wall slippage so that maximum size of the fluid’s plug is maintained. Based on this concept the study qualifies the wall slippage effect as a rheological property to be used in fluid’s selection and evaluation for the purpose of wellbore displacement. The effect is analyzed using a conceptual model of fluid motion between two parallel plates to define the relationship between velocity of undisturbed fluid plug (slip velocity) and shearing rate for the maximum slippage effect. Applying the analysis to coaxial geometry gives practical formulas and a simplified procedure for fluid testing using either modified or conventional rotational viscometer. Also defined are new parameters of the fluid’s displacement performance: Maximum Slip Velocity and Plug Displacement Index. The study evaluates a variety of water-base drilling fluids such as high-molecular-weight polymer solutions, dispersed clay suspensions and suspensions flocculated with different electrolytes. The results show that the best-performing displacement fluid is a prehydrated bentonite suspension flocculated with sodium chloride.
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Chen, Hongbo, und Ergun Kuru. „Dynamic Filtration Loss Control Through Optimization of Drilling Fluid Rheological Properties: A Comparative Study of the Fluid Viscoelasticity Versus Shear Viscosity Effects“. In ASME 2023 42nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/omae2023-100573.
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Abstract Shear viscosity and elasticity have been identified as two of the most influential factors controlling the volume of drilling fluid invasion into reservoir and the resultant formation damage. Past studies were inconclusive regarding individual effects of fluid shear viscosity vs elasticity, as it was challenging to disintegrate and measure their impacts independently. Therefore, we investigated the relative contributions of the fluid shear viscosity and the elasticity on the fluid invasion and the resultant productivity impairment. 24 water-based drilling fluids were prepared using various blends of three different molecular weight PHPA polymers. Detailed rheological characterizations of these fluids were carried out by conducting amplitude sweep and controlled shear rate tests. Viscoelastic properties of the fluids were quantified in terms of energy dissipation, which physically signifies the amount of energy required per unit volume to cause an irreversible deformation in the fluid’s internal structure. Static filtration tests and core flooding experiments were conducted to determine the static fluid loss, pressure drop across the cores at different flow rates, and the resultant formation damage induced by each fluid. Using a unique technique we developed in our previous work, we have formulated two groups of fluids; one group with the same shear viscosity and variable elasticity and the other group with the same elasticity and variable shear viscosities. Hence, we could investigate the individual effects of shear viscosity and elasticity on the static and dynamic filtration loss and the resultant formation damage. By investigating the independent effects of viscoelasticity and shear viscosity on the fluid filtration loss characteristics, we have observed that: 1-) The static filtration rate can be more effectively reduced by altering fluid viscoelasticity as compared to the fluid shear viscosity. 2-) Both shear viscosity and viscoelasticity have a direct relationship to the pressure drop associated with the core flow. However, the effect of viscoelasticity on the pressure drop is more pronounced. 3-) Increasing fluid viscoelasticity inhibits fluid invasion into the formation better than that of the fluid shear viscosity. 4-) The results have suggested that viscoelasticity can be effectively used for developing non-invasive fluids, which would reduce static filtration rate, increase pressure drop (i.e. building internal cake), and minimize formation damage by effectively reducing fluids invasion. The study introduces an innovative approach to investigate the fluid loss and formation damage characteristics of viscoelastic, solids-free drilling fluids. The sole effects of shear viscosity and viscoelasticity on filtration loss characteristics were investigated and compared. Understanding the mechanisms of internal cake formation and their quantitative relation to fluid viscous and elastic properties will help the design of optimum drilling and completion fluids and, hence, minimize the productivity reduction associated with applications of these fluids.
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Haque, Ainul, und Ameeya Kumar Nayak. „Mixed Electroosmotic Pressure Driven Flow and Heat Transfer of Power Law Fluid in a Hydrophobic Microchannel“. In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69525.
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In this paper, a mathematical model has been developed to analyze the combined electroosmotic and pressure driven flow of power law fluids in a micro channel in the presence of Joule heating effects. The effects of Navier slip boundary condition and thermal radiation is examined for effective heat transfer in a hydrophobic microchannel. The analytical treatment has been performed for fluid flow and heat transfer effects in terms of flow governing parameters. This study highlights the effect of channel height to the electric double layer thickness and observed the flow variation due to heat transfer effect with the available scientific data. For a pure EOF, velocity slip have more significant role to get a maximum flow rate as expected. For both pseudo-plastic and dilatent fluids Nusselt number is decreased with the increment of the hydrophobic parameter and dimensionless pressure gradient where as increment in Joule heating effect enhance the heat transfer rate.
Berichte der Organisationen zum Thema "Effets fluides"
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Phelps, M. R., M. O. Hogan und L. J. Silva. Fluid dynamic effects on precision cleaning with supercritical fluids. Office of Scientific and Technical Information (OSTI), Juni 1994. http://dx.doi.org/10.2172/10165549.
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Phelps, M. R., W. A. Willcox, L. J. Silva und R. S. Butner. Effects of fluid dynamics on cleaning efficacy of supercritical fluids. Office of Scientific and Technical Information (OSTI), März 1993. http://dx.doi.org/10.2172/10136973.
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Phelps, M. R., W. A. Willcox, L. J. Silva und R. S. Butner. Effects of fluid dynamics on cleaning efficacy of supercritical fluids. Office of Scientific and Technical Information (OSTI), März 1993. http://dx.doi.org/10.2172/6665473.
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Apps, Christopher, und Tyler Johnson. PR244-173902-R01 On-water Leak Detection System Evaluation. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), Juli 2018. http://dx.doi.org/10.55274/r0011504.
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The hydrocarbon industry is directing efforts towards reducing the environmental impact of operation through improving pipeline performance and addressing evolving regulatory requirements. As a result, many different external leak detection technologies have been recently developed; however, it is challenging to test these systems with real hydrocarbon products. The research project described herein evaluated the performance of six external leak detection systems intended to identify the presence of hydrocarbon products on the surface of water. The scope was limited to an idealized freshwater environment. Tests were conducted with five hydrocarbon test fluids (gasoline, diesel, Synthetic Sweet Blend, Access Western Blend and Cold Lake Blend) along with three additional test fluids (canola oil, salt water and motor oil). Canola oil was considered as a candidate surrogate fluid and salt water as a possible source of false alarms, while motor oil was considered as a candidate surrogate fluid or a false alarm trigger, depending on the field application. Testing was performed by releasing each test fluid onto the surface of a water basin with six sensors located equidistant from the release point. Each sensor's response to contact with the test fluid was monitored and compared based on time to detection and estimated slick thickness at detection.
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Weitsman, Y. J. Effects of Fluids on Polymeric Composites - A Review. Fort Belvoir, VA: Defense Technical Information Center, Juli 1995. http://dx.doi.org/10.21236/ada297030.
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Remy, David, und Leonard A. Levasseur. The Effects of Supercritical Fluids on High Performance Polymers. Fort Belvoir, VA: Defense Technical Information Center, Februar 1989. http://dx.doi.org/10.21236/ada206515.
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Kirkpatrick, J. R. Fluid flow effects on electroplating. Office of Scientific and Technical Information (OSTI), September 1990. http://dx.doi.org/10.2172/6430941.
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Hawley, Adam, Mustexist Gutierrez und John McCleney. PR-015-19605-R01 Effect of Upstream Piping on Ultrasonic Meter Bias - End Treatment Effects. Chantilly, Virginia: Pipeline Research Council International, Inc., April 2023. http://dx.doi.org/10.55274/r009999.
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This project evaluated current end treatment designs that are used in the natural gas industry and used Computational Fluid Dynamics (CFD) to determine the end treatment with the best flow characteristics when installed upstream from an ultrasonic flow meter. The project team optimized the end treatment design and additional CFD and experimental testing was conducted. The experimental results of the developed end treatment were shown to provide results within ±0.25% relative to the baseline configuration with various inlet conditions and numbers of ultrasonic paths.
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Hawley, Adam, Luis Gutierrez und Amy McCleney. PR-015-19605-R01 Effect of Upstream Piping on Ultrasonic Meter Bias - End Treatment Effects. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), April 2023. http://dx.doi.org/10.55274/r0012256.
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This project evaluated current end treatment designs that are used in the natural gas industry and used Computational Fluid Dynamics (CFD) to determine the end treatment with the best flow characteristics when installed upstream from an ultrasonic flow meter. The project team optimized the end treatment design and additional CFD and experimental testing was conducted. The experimental results of the developed end treatment were shown to provide results within �0.25% relative to the baseline configuration with various inlet conditions and numbers of ultrasonic paths.
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McCleney, Amy, und Terry Grimley. PR-015-17604-R02 Static Mixer Assessment Laboratory Testing. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2020. http://dx.doi.org/10.55274/r0011771.
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Static mixers are nonmoving mixing devices that allow for the inline continuous mixing of fluids within a pipeline. Liquid samples are typically extracted downstream of the mixer to evaluate the composition of the fluid. However, the ability of mixers to provide a uniformly mixed sample and the acceptable distances at which this sample can be taken from the pipe for this composition evaluation are currently unknown. A testing effort was initiated to determine the effectiveness of two different static mixer designs, as well as sampling locations, by flowing known quantities of oil and water past these devices at a constant flow rate, with two oil viscosity values of 3 cSt and 400 cSt, and with two nominal water-cut values of 1% and 10%. To evaluate their mixing abilities, fluid samples were drawn from the pipe at three locations downstream of the mixers and at three pipe elevations. These samples were assessed using two different analysis methods: a centrifuge method using ASTM D4007 (2016) for the nominal 10% water-cut tests and a Karl Fisher analysis method using ASTM D4928 (2018) for the nominal 1% water-cut tests. The results from the sample measurements will allow the PRCI members to assess the mixing and stratification effects of different static mixer designs and at different sample locations.