Academic literature on the topic 'Pointe polymère'
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Journal articles on the topic "Pointe polymère":
1
Pelletier, H., C. Gauthier, and R. Schirrer. "Analyses des sillons viscoélastiques lors d'un contact entre une pointe rigide et la surface d'un polymère." Matériaux & Techniques 96, no. 3 (2008): 111–20. http://dx.doi.org/10.1051/mattech:2008026.
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Chen, Weifeng, Shaona Chen, Weimin Hu, Dejiang Li, and Zhongxu Dai. "The Preparation Approaches of Polymer/graphene Nanocomposites and their Appilcation Research Progress as Electrochemical Sensors." Journal of New Materials for Electrochemical Systems 20, no. 4 (October 31, 2017): 205–21. http://dx.doi.org/10.14447/jnmes.v20i4.356.
Abstract:
Graphene, a two-dimensional sheet of sp2-hybridized carbon atoms packed into a honeycomb lattice, can be combined with various polymers through different methods and techniques. Polymer/graphene nanocomposites are expected to not only preserve the fa-vorable properties of graphene and polymers, but also greatly enhance the intrinsic properties due to the synergetic effect between them. In this review, the preparation approaches of graphene/polymer nanocomposites, including melt blending, solution blending, in-situ polymeri-zation and in-situ synthesis, were presented comprehensively in order to study the relationship between these approaches and the final characteristics and performances. Each approach had different influences on the final properties of the nanocomposites. The advantages and disadvantages of the preparation methods were discussed respectively. Additionally, the application researches of the polymer/graphene nanocomposites as electrochemical sensors, were introduced in detail. With regard to some important or novel sensors, the mechanisms were proposed for reference. Finally, conclusions were given and the issues waiting to be settled for further development were pointed out. The current review demonstrates that polymer/graphene nanocomposites exhibit superior electrochemical performances and will be applied practically in the field of sensor devices.
3
Ma, Liang. "Comparing the Principles of Reversible Covalent Chemistry and Supramolecular Chemistry Points to New Directions in the Development of Polymers." Highlights in Science, Engineering and Technology 26 (December 30, 2022): 446–54. http://dx.doi.org/10.54097/hset.v26i.4025.
Abstract:
Polymers are some of the most widely used materials for human use and have greatly facilitated people's lives. However, with the use of polymer materials, traditional thermoplastic and thermoset materials are unable to meet the more diverse needs, and traditional processing methods are not able to significantly improve the performance of polymer materials. Some researchers have found that by applying the principles of reversible covalent and supramolecular chemistry in dynamic chemistry in the development of polymers, the properties and functions of polymers can be changed from the bottom up. Therefore, this paper analyses the similarities and differences between the principles of reversible covalent chemistry and supramolecular chemistry by collecting applications of reversible covalent chemistry and supramolecular chemistry in the field of polymer synthesis and comparing the two to provide assistance for future developments in the field of polymers.
4
Hu, Jin Lian, and Jing Lu. "Shape Memory Polymers in Textiles." Advances in Science and Technology 80 (September 2012): 30–38. http://dx.doi.org/10.4028/www.scientific.net/ast.80.30.
Abstract:
This paper highlight the most important areas and directions of shape memory polymers in textiles. The textiles of shape memory polymers involve fibre spinning (including wet-spinning, melt-spinning and electro-spinning), fabric, smart apparel, actively finishing technology and WVP investigation. Based on the molecular structure of shape memory polymer, the shape memory transformation from polymer to textiles and application theory are illustrated and stated. Additionally, the challenges of shape memory polymers in textiles are pointed out and some research directions are also suggested in this paper.
5
Valenzuela, Loreto M., Doyle D. Knight, and Joachim Kohn. "Developing a Suitable Model for Water Uptake for Biodegradable Polymers Using Small Training Sets." International Journal of Biomaterials 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/6273414.
Abstract:
Prediction of the dynamic properties of water uptake across polymer libraries can accelerate polymer selection for a specific application. We first built semiempirical models using Artificial Neural Networks and all water uptake data, as individual input. These models give very good correlations (R2>0.78for test set) but very low accuracy on cross-validation sets (less than 19% of experimental points within experimental error). Instead, using consolidated parameters like equilibrium water uptake a good model is obtained (R2=0.78for test set), with accurate predictions for 50% of tested polymers. The semiempirical model was applied to the 56-polymer library of L-tyrosine-derived polyarylates, identifying groups of polymers that are likely to satisfy design criteria for water uptake. This research demonstrates that a surrogate modeling effort can reduce the number of polymers that must be synthesized and characterized to identify an appropriate polymer that meets certain performance criteria.
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Zore, Ashish, Peng Geng, Yuwei Zhang, and Michael R. Van De Mark. "Defining the Collapse Point in Colloidal Unimolecular Polymer (CUP) Formation." Polymers 14, no. 9 (May 7, 2022): 1909. http://dx.doi.org/10.3390/polym14091909.
Abstract:
Colloidal unimolecular polymer (CUP) particles were made using polymers with different ratios of hydrophobic and hydrophilic monomers via a self-organization process known as water reduction. The water-reduction process and the collapse of the polymer chain to form a CUP were tracked using viscosity measurements as a function of composition. A vibration viscometer, which allowed for viscosity measurement as the water was being added during the water-reduction process, was utilized. The protocol was optimized and tested for factors such as temperature control, loss of material, measurement stability while stirring, and changes in the solution volume with the addition of water. The resulting viscosity curve provided the composition of Tetrahydrofuran (THF)/water mixture that triggers the collapse of a polymer chain into a particle. Hansen as well as dielectric parameters were related to the polymer composition and percentage v/v of THF/water mixture at the collapse point. It was observed that the collapse of the polymer chain occurred when the water/THF composition was at a water volume of between 53.8 to 59.3% in the solvent mixture.
7
Browne, Emer, Zelalem A. Worku, and Anne Marie Healy. "Physicochemical Properties of Poly-vinyl Polymers and Their Influence on Ketoprofen Amorphous Solid Dispersion Performance: A Polymer Selection Case Study." Pharmaceutics 12, no. 5 (May 8, 2020): 433. http://dx.doi.org/10.3390/pharmaceutics12050433.
Abstract:
When developing an amorphous solid dispersion (ASD), a prudent choice of polymer is critical to several aspects of ASD performance including: processability, solid state stability and dissolution rate. However, there is little guidance available to formulators to aid judicious polymer selection and a “trial and error” approach is often taken. This study aims to facilitate rational polymer selection and formulation design by generating ASDs using a range of poly-vinyl polymers and ketoprofen as a model active pharmaceutical ingredient (API) and evaluating several aspects of their performance. The molecular weight of the polymer and the ratio of vinyl pyrrolidone to vinyl acetate in the polymer were found to influence the relative humidity at which the relative humidity induced glass transition occurred, as well as the extent of ketoprofen supersaturation achieved during dynamic solubility testing. Interestingly, ASD tablets containing polymers with the vinyl pyrrolidone functional group exhibited higher tensile strengths than those without. This points towards the binder functionality of vinyl pyrrolidone. In conclusion, the physicochemical properties of poly-vinyl polymers greatly influence ketoprofen ASD performance and due regard should be paid to these properties in order to develop an ASD with the desired attributes.
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Nizina, T. A., Dmitrii R. Nizin, N. S. Kanaeva, N. M. Kuznetsov, and D. A. Artamonov. "Applying the Fractal Analysis Methods for the Study of the Mechanisms of Deformation and Destruction of Polymeric Material Samples Affected by Tensile Stresses." Key Engineering Materials 799 (April 2019): 217–22. http://dx.doi.org/10.4028/www.scientific.net/kem.799.217.
Abstract:
The paper proposes an approach to study the mechanism of deformation of epoxy polymers based on the methods of fractal calculations. The advantages of the method for determining the fractality index of the deformation curves of polymer samples using the minimum coverage method are shown. An algorithm for the quantitative determination of the location of the "critical" points of the deformation curves of polymer samples under tension is proposed. It is shown that the use of the developed methodology for the fractal analysis of time series on the basis of a set of points of deformation curves of epoxy polymer samples under tension, provides valuable information about the processes occurring in the structure of composite materials affected by mechanical loads and various aggressive factors.
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Peram, Shyamsundar Reddy, Madhava Rao Byraboina, Narendran Dama, Suryanarayana Murthy Kurivella, and Jagadish Mandava. "An Overview of Thermal Behavior of Polymers: Lead Acid Battery Applications." European Journal of Engineering and Technology Research 7, no. 1 (January 10, 2022): 12–17. http://dx.doi.org/10.24018/ej-eng.2022.7.1.2704.
Abstract:
Thermal analysis is the analysis of a change in a property of a material, which is related to the temperature difference. Polymer samples are typically in solid form and undergo various thermal transitions upon heating, including melting, phase transition, sublimation, and decomposition. The purpose of this study is to demonstrate how thermal techniques such as DSC and TGA may be used to evaluate polymer thermal stability through the examination of polymer characteristics such as glass transition temperatures, melting points, and mass changes. Different polymers have been investigated and used in lead-acid batteries for various applications based on their mechanical and thermal characteristics. Few lead-acid battery-related polymers like Polypropylene (PP), Polyethylene (PE) Separator, Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) and Acrylonitrile butadiene styrene (ABS) were studied and explained.
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Peram, Shyamsundar Reddy, Madhava Rao Byraboina, Narendran Dama, Suryanarayana Murthy Kurivella, and Jagadish Mandava. "An Overview of Thermal Behavior of Polymers: Lead Acid Battery Applications." European Journal of Engineering and Technology Research 7, no. 1 (January 10, 2022): 12–17. http://dx.doi.org/10.24018/ejeng.2022.7.1.2704.
Abstract:
Thermal analysis is the analysis of a change in a property of a material, which is related to the temperature difference. Polymer samples are typically in solid form and undergo various thermal transitions upon heating, including melting, phase transition, sublimation, and decomposition. The purpose of this study is to demonstrate how thermal techniques such as DSC and TGA may be used to evaluate polymer thermal stability through the examination of polymer characteristics such as glass transition temperatures, melting points, and mass changes. Different polymers have been investigated and used in lead-acid batteries for various applications based on their mechanical and thermal characteristics. Few lead-acid battery-related polymers like Polypropylene (PP), Polyethylene (PE) Separator, Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) and Acrylonitrile butadiene styrene (ABS) were studied and explained.
Dissertations / Theses on the topic "Pointe polymère":
1
Pham, Thi Nhung. "Fabry-Perot interferometer based on end-of-fiber polymer microtip for chemical sensing." Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0006.
Abstract:
Les interféromètres Fabry-Perot (FPI) ont reçu un grand intérêt pour leur utilisation en tant que capteurs. Les FPI sont constitués d'une cavité optique avec des surfaces parallèles qui réfléchissent la lumière incidente, produisant un signal interférométrique optique. Ce signal dépend de la distance entre les surfaces réfléchissantes et de l'indice de réfraction de la cavité, qui sont sensibles aux variations d’humidité, de température, de pression et du matériau. Les FPI peuvent être attachés à des fibres optiques, qui fonctionnent comme un guide d'ondes pour le signal incident et le signal réfléchi, et former ainsi des capteurs compacts. Cette thèse présente des capteurs chimiques à base de FPI incorporant une micropointe en polymère structurée à l'extrémité d'une fibre optique, étudiés pour la détection d'humidité, d'eau et de cibles chimiques.Tout d'abord, nous développons une pointe de triacrylate de pentaérythritol (PETA) sur la facette d'une fibre optique par photopolymérisation autoguidée. Une extrémité de la fibre est placée dans une goutte de PETA et la photopolymérisation est activée par un laser de 375 nm injecté à l'autre extrémité de la fibre. Les conditions optimales pour former une pointe PETA mécaniquement stable sont 1μW de puissance laser × 1s de temps d'exposition. Cependant, les chaînes PETA ne sont pas complètement polymérisées lors de cette étape, ce qui entraîne une fréquence de résonance instable de la pointe. La pointe doit donc être post-polymérisée sous une lampe UV de 365nm pour obtenir une caractéristique dynamique stable, avant leur application en tant que capteur.Deuxièmement, nous démontrons que la pointe PETA est un capteur efficace pour détecter l'humidité. Elle fonctionne comme une cavité optique formée entre le cœur de la fibre/PETA et l'interface PETA/environnement, ce qui permet d'obtenir un signal interférométrique clair. Le signal FPI de la pointe est très sensible à l'humidité de l'air grâce aux groupes hydroxyles du PETA, qui absorbent les molécules d'eau dans l'air humide, induisant un gonflement de la pointe. La longueur et/ou l'indice de réfraction sont donc modifiés, ce qui entraîne une variation du signal interférométrique. La pointe présente une sensibilité constante de 90 pm/%RH, équivalent à une sensibilité relative de 104 ppm/%RH pour une plage d'humidité de 30 à 80 %. La détection est hautement reproductible et stable. En outre, l'effet de la température est négligeable, favorisant leur potentiel d’application.Ensuite, nous appliquons les pointes PETA basées sur le FPI pour déterminer la teneur en eau de solutions de glycérol et d'éthylène glycol. Le signal FPI de la pointe PETA varie de manière non linéaire lorsque la teneur en eau passe de 0 à 100% en poids. La variation du signal FPI est due à la contraction de la pointe, qui est liée à la perte d'eau à l'intérieur de la structure PETA. Lorsque la contamination par l'eau est inférieure à 10%, la pointe présente une sensibilité de 394 pm/wt.% et 226 pm/wt.% pour les solutions de glycérol et d'éthylène glycol, respectivement. Ainsi, la pointe PETA basée sur le FPI présente un grand potentiel pour la détermination de la teneur en eau de solutions aqueuses, y compris les hydrocarbures.Enfin, une pointe constituée d'un cœur PETA et d'une enveloppe de polymères à empreintes moléculaires (MIP) a été mise au point pour détecter la Dansyl-L-phénylalanine. La pointe PETA est initialement fabriquée en utilisant la polymérisation autoguidée et les MIP sont ensuite copolymérisés pour former une fine couche d'enveloppe autour de la pointe PETA. Lors de la détection sélective de la Dansyl-L-phénylalanine, l'indice de réfraction de la couche de MIP change, ce qui entraîne une modification du signal FPI de l'ensemble de la pointe PETA/MIP. Cette méthode simple offre de nouvelles possibilités pour créer des capteurs à fibre optique MIP à base de FPI applicables à une large gamme d'analytes, qu’ils soient fluorescents ou nonFabry−Perot interferometers (FPIs) have received a significant attention for their use in sensor applications. FPIs consist of an optical cavity with separate parallel reflecting surfaces which reflect incident light, resulting in an optical interferometric signal. The FPI signal depends on the distance between the reflecting surfaces and the refractive index of the cavity medium, which are sensitive to variation of environment humidity, temperature, pressure, and material. FPIs can be attached to optical fibers to form compact fiber optic FPI-based sensors in which the optical fiber works as a waveguide for both incident and reflected signal. This thesis presents FPI-based chemical sensors incorporating a polymer microtip located at the end of an optical fiber and characterizes their sensing capabilities for humidity, water, and chemical targets.Firstly, we develop a pentaerythritol triacrylate (PETA) tip on the facet of an optical fiber by a self-guiding photopolymerization. One end of the optical fiber is placed inside a PETA droplet and the self-guiding photopolymerization of PETA is actuated by a 375 nm laser injected to the other end of the fiber. The optimal conditions to form a straight and mechanically stable PETA tip are 1.0 μW of laser power × 1.0 second of exposure time. However, the PETA chains do not completely polymerize during this self-polymerization, leading to an unstable dynamic resonant frequency of the tip. Thus, the tip needs a post-polymerization under a UV 365 nm lamp to achieve a stable dynamic characteristic, which is applicable for further sensing applications.Secondly, we demonstrate the PETA tip as an effective sensor to detect humidity. The PETA tip acts as an optical cavity formed between the fiber-core/PETA and the PETA/environment interface, resulting in a clear interferometric signal. The FPI signal of the tip is highly sensitive to humidity in the air. This is due to hydroxyl groups within the PETA structure, which strongly absorb water molecules in the humid air and significantly swell the tip. The length and/or the refractive index of the tip are therefore changed, resulting in a FPI shift. The tip exhibits a consistent sensitivity of 90pm/%RH, equivalent to a relative sensitivity of 104 ppm/%RH in the humidity range from 30 to 80%. The sensing performance is highly reproducible and stable. Furthermore, the cross effect of the temperature is negligible, indicating a great practical potential for the devices.Next, we apply the FPI-based PETA tips to determine the water content in glycerol and ethylene glycol solutions. The FPI signal of the PETA tip shifts nonlinearly towards longer wavelengths as the water content increases from 0 to 100 wt.%. The shift in the FPI signal occurs due to the contraction in the tip length, which is linked to the loss of water inside the PETA structure caused by the hydrophilic solutions. When the water contamination is below 10 wt.%, the tip shows a sensitivity of 394 pm/wt.% and 226 pm/wt.% for glycerol and ethylene glycol solutions, respectively. Therefore, the FPI-based PETA tip shows a great potential in determining water content in hydrophilic aqueous solutions, including hydrocarbons.Finally, a tip consisting of a PETA core and a shell of molecularly imprinted polymers (MIPs) is developed for detecting Dansyl-L-phenylalanine. The PETA tip is initially fabricated using the self-guiding polymerization and MIPs are then copolymerized to form a thin shell layer around the PETA tip. Upon the selective binding of Dansyl-L-phenylalanine, the refractive index of the MIP layer changes, leading to the change in the FPI signal of the whole PETA/MIP tip. This straightforward and affordable method offers new innovative possibilities for creating FPI-based MIP fiber optic sensors, which can be applied for a wide range of analytes, including both non-fluorescent and fluorescent targets
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Piluso, Pierre. "Développement de nouvelles formulations à base de polymères fonctionnels pour la mise au point de papiers techniques à propriétés spécifiques." Electronic Thesis or Diss., Lyon, 2018. http://www.theses.fr/2018LYSE1090.
Abstract:
Cette thèse a consisté à étudier la réaction d'acétalisation en milieu aqueux de l'alcool polyvinylique (PVA) par un aldéhyde non hydrosoluble à longue chaîne alkyle (10-14 carbones) porteur d'une fonctionnalité vinyle en bout de chaîne, pour des conditions spécifiques : concentration en polymère de 8 % massique et degrés d'acétalisation (DA) faibles (<5,6 mol%). L'objectif de cette réaction de greffage est l'obtention de films obtenus par évaporation de solvant ayant une fonctionnalité de surface. L'influence des paramètres de réaction (concentration en réactifs, pH) sur la cinétique a été étudiée sur un composé modèle, le pentane-2,4-diol, puis sur le PVA. Une méthode de dosage par RMN 1H a permis d'identifier et de quantifier les composés en présence dans le milieu de réaction.Un objectif de la thèse a été de maximiser le DA en conservant une viscosité adéquate pour un procédé d'enduction. Pour cela, l'impact du greffage par le 10-undécénal sur l'organisation et les propriétés rhéologiques des solutions d'un PVA référence à 8 % massique a été étudié en premier lieu jusqu'à un DA de 1,85 mol%. Une méthode de quantification de faibles quantités de groupements vinyle en surface des films de PVA acétalisé a permis d'étudier leur orientation en surface pour une gamme de DA de 0 à 1,48 mol%.L'influence de la masse molaire du PVA et de la longueur de chaîne alkyle de l'aldéhyde sur la cinétique d'acétalisation et son impact sur la viscosité des solutions ont également été étudiés. L'utilisation d'un PVA de masse molaire plus faible apparait être un moyen efficace de maximiser le DA tout en conservant une viscosité acceptable pour un procédé d'enductionThis PhD work dealt with the study of the acetalization reaction of polyvinyl alcohol (PVA) in aqueous medium by non-water soluble aldehydes bearing long alkyl chains and a vinyl end group such as 10-undecenal in specific conditions: in 8 wt% concentrated PVA solutions and with low acetalization degree (AD) from 0.33 mol% to 5.6 mol%. The main purpose of this grafting reaction is to obtain an activated surface on water casted polymer films. First, the impact of reactants concentrations, pH and reaction atmosphere on the acetalization kinetics was studied with a model compound first, pentane-2,4-diol, then with PVA. A new 1H NMR titration method allowed to carry out in situ quantification of the amount of reactant and of grafted aldehyde.On main objectives of this work was to obtain the highest DA while keeping PVA solutions viscosity as low as possible to keep a sufficiently low solution viscosity for a solvent cast process. The impact of AD by 10-undecenal on PVA solution organization and on the rheological properties of 8 wt% PVA aqueous solutions were investigated first until 1.85 mol% AD. A surface vinyl groups quantification method was developed through chemical labeling of the vinyl groups at the surface of solvent casted PVA films and 1H NMR titration of the labels. This method allowed the study of vinyl groups orientation toward the surface of acetalized PVA films until 1.48 mol% AD.The influence of PVA molar mass and of aldehyde alkyl chain length on acetalization kinetics and solutions viscosity was also studied. The use of a low molar mass polymer appeared to be an efficient way to obtain highly modified films while keeping a low 8 wt% acetalized PVA solution viscosity
3
Piluso, Pierre. "Développement de nouvelles formulations à base de polymères fonctionnels pour la mise au point de papiers techniques à propriétés spécifiques." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1090.
Abstract:
Cette thèse a consisté à étudier la réaction d'acétalisation en milieu aqueux de l'alcool polyvinylique (PVA) par un aldéhyde non hydrosoluble à longue chaîne alkyle (10-14 carbones) porteur d'une fonctionnalité vinyle en bout de chaîne, pour des conditions spécifiques : concentration en polymère de 8 % massique et degrés d'acétalisation (DA) faibles (<5,6 mol%). L'objectif de cette réaction de greffage est l'obtention de films obtenus par évaporation de solvant ayant une fonctionnalité de surface. L'influence des paramètres de réaction (concentration en réactifs, pH) sur la cinétique a été étudiée sur un composé modèle, le pentane-2,4-diol, puis sur le PVA. Une méthode de dosage par RMN 1H a permis d'identifier et de quantifier les composés en présence dans le milieu de réaction.Un objectif de la thèse a été de maximiser le DA en conservant une viscosité adéquate pour un procédé d'enduction. Pour cela, l'impact du greffage par le 10-undécénal sur l'organisation et les propriétés rhéologiques des solutions d'un PVA référence à 8 % massique a été étudié en premier lieu jusqu'à un DA de 1,85 mol%. Une méthode de quantification de faibles quantités de groupements vinyle en surface des films de PVA acétalisé a permis d'étudier leur orientation en surface pour une gamme de DA de 0 à 1,48 mol%.L'influence de la masse molaire du PVA et de la longueur de chaîne alkyle de l'aldéhyde sur la cinétique d'acétalisation et son impact sur la viscosité des solutions ont également été étudiés. L'utilisation d'un PVA de masse molaire plus faible apparait être un moyen efficace de maximiser le DA tout en conservant une viscosité acceptable pour un procédé d'enductionThis PhD work dealt with the study of the acetalization reaction of polyvinyl alcohol (PVA) in aqueous medium by non-water soluble aldehydes bearing long alkyl chains and a vinyl end group such as 10-undecenal in specific conditions: in 8 wt% concentrated PVA solutions and with low acetalization degree (AD) from 0.33 mol% to 5.6 mol%. The main purpose of this grafting reaction is to obtain an activated surface on water casted polymer films. First, the impact of reactants concentrations, pH and reaction atmosphere on the acetalization kinetics was studied with a model compound first, pentane-2,4-diol, then with PVA. A new 1H NMR titration method allowed to carry out in situ quantification of the amount of reactant and of grafted aldehyde.On main objectives of this work was to obtain the highest DA while keeping PVA solutions viscosity as low as possible to keep a sufficiently low solution viscosity for a solvent cast process. The impact of AD by 10-undecenal on PVA solution organization and on the rheological properties of 8 wt% PVA aqueous solutions were investigated first until 1.85 mol% AD. A surface vinyl groups quantification method was developed through chemical labeling of the vinyl groups at the surface of solvent casted PVA films and 1H NMR titration of the labels. This method allowed the study of vinyl groups orientation toward the surface of acetalized PVA films until 1.48 mol% AD.The influence of PVA molar mass and of aldehyde alkyl chain length on acetalization kinetics and solutions viscosity was also studied. The use of a low molar mass polymer appeared to be an efficient way to obtain highly modified films while keeping a low 8 wt% acetalized PVA solution viscosity
4
Torri, Niccolò. "Phénomènes de localisation et d’universalité pour des polymères aléatoires." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10114/document.
Abstract:
Le modèle d'accrochage de polymère décrit le comportement d'une chaîne de Markov en interaction avec un état donné. Cette interaction peut attirer ou repousser la chaîne de Markov et elle est modulée par deux paramètres, h et β. Quand β = 0 on parle de modèle homogène, qui est complètement solvable. Le modèle désordonné, i.e. quand β > 0, est mathématiquement le plus intéressant. Dans ce cas, l'interaction dépend d'une source d'aléa extérieur indépendant de la chaîne de Markov, appelée désordre. L'interaction est réalisée en modifiant la loi originelle de la chaîne de Markov par une mesure de Gibbs et la probabilité obtenue définit le modèle d'accrochage de polymère. Le but principal est d'étudier et de comprendre la structure des trajectoires typiques de la chaîne de Markov sous cette nouvelle probabilité. Le premier sujet de recherche concerne le modèle d'accrochage de polymère où le désordre est à queues lourdes et où le temps de retour de la chaîne de Markov suit une distribution sous-exponentielle. Dans notre deuxième résultat nous étudions le modèle d'accrochage de polymère avec un désordre à queues légères et le temps de retour de la chaîne de Markov avec une distribution à queues polynomiales d'exposant α > 0. On peut démontrer qu'il existe un point critique, h(β). Notre but est comprendre le comportement du point critique quand β -> 0. La réponse dépend de la valeur de α. Dans la littérature on a des résultats précis pour α < ½ et α > 1. Nous montrons que α ∈ (1/2, 1) le comportement du modèle dans la limite du désordre faible est universel et le point critique, opportunément changé d'échelle, converge vers la même quantité donnée par un modèle continuThe pinning model describes the behavior of a Markov chain in interaction with a distinguished state. This interaction can attract or repel the Markov chain path with a force tuned by two parameters, h and β. If β = 0 we obtain the homogeneous pinning model, which is completely solvable. The disordered pinning model, i.e. when β > 0, is most challenging and mathematically interesting. In this case the interaction depends on an external source of randomness, independent of the Markov chain, called disorder. The interaction is realized by perturbing the original Markov chain law via a Gibbs measure, which defines the Pinning Model. Our main aim is to understand the structure of a typical Markov chain path under this new probability measure. The first research topic of this thesis is the pinning model in which the disorder is heavy-tailed and the return times of the Markov chain have a sub-exponential distribution. In our second result we consider a pinning model with a light-tailed disorder and the return times of the Markov chain with a polynomial tail distribution, with exponent α > 0. It is possible to show that there exists a critical point, h(β). Our goal is to understand the behavior of the critical point when β -> 0. The answer depends on the value of α and in the literature there are precise results only for the case α < ½ et α > 1. We show that for α ∈ (1/2, 1) the behavior of the pinning model in the weak disorder limit is universal and the critical point, suitably rescaled, converges to the related quantity of a continuum model
5
Massines, Françoise. "Mise au point d'une technique ultrasonore pour la caracterisation des polymeres en fonction de la temperature et de la pression." Toulouse 3, 1987. http://www.theses.fr/1987TOU30030.
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Boivin, Mathieu. "Contrôle de la morphologie dans les cellules solaires hybrides polymère-points quantiques colloïdaux." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27761/27761.pdf.
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Gargouri, Myriem. "Mise au point de nanoparticules polycationiques pour le transfert de gènes." Thesis, Nancy 1, 2010. http://www.theses.fr/2010NAN10061/document.
Abstract:
L'objectif de cette étude est de développer des « outils vecteur d'ADN » à base de polymères. Les nanoparticules développées ont été formulées par nanoprécipitation ou par double émulsion et évaporation de solvant, et on été caractérisées physicochimiquement comprenant la détermination de la taille, le potentiel zêta et la quantité d'ADN adsorbée à leur surface. La cytotoxicité et l'efficacité de transfection des différents vecteurs d'ADN ont été étudiées sur différentes lignées cellulaires. Pour améliorer le franchissement des membranes cellulaires, la technique d'internalisation photochimique a été utilisée. L'association des vecteurs à cette méthodologie n'a pas atteint les résultats escomptés, les vecteurs synthétisés représentent à nos yeux une alternative prometteuse en thérapie génique pour élaborer des outils stables, efficaces pour le transport d'acides nucléiques dans les cellules et utilisables directement au chevet du patientThe aim of this study is to develop non-viral delivery systems for DNA. Nanoparticles were prepared by using nanoprecipitation and double emulsion methods. The nanoparticles were characterized physicochemical. Cytotoxicity and transfection efficiency of nanoparticles were performed in different cell lines. Cytotoxicity tests based on mitochondrial activity revealed that all type of nanoparticles had limited cytotoxicity, but depending on both the cell type and the nanoparticles concentration. In order to increase transfection efficiency, photochemical internalization was used to improve endosomal release of nanoparticles. All the results revealed the difficulty to elaborate an efficient DNA vector presenting a low cytotoxicity
8
Leblanc, Jonathan. "Étude et mise au point d'un procédé d'élaboration de mélanges à base de polyamides combinant un pilote de polycondensation et des mélangeurs statiques." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL046N.
Abstract:
Ces travaux de recherche portent sur le développement d’un procédé permettant de mélanger, directement en sortie de polycondensation, du polyamide fondu avec d’autres polymères immiscibles en tant qu’additifs. Ce procédé se distingue ainsi des méthodes d’élaboration conventionnelles pour lesquelles une fusion préalable des polymères est nécessaire. L’étude concerne le mélange de polymères de viscosités très différentes (polyamide 66 et polyéthylène glycol) et le mélange de polymères de viscosités similaires (polyamide 66 et copolymère d’éthylène propylène, en présence ou non d’un agent d’interface : polypropylène greffé par de l’anhydride maléique).Une première partie de ce travail a consisté à caractériser la dispersion de ces mélanges élaborés selon des procédés conventionnels. Ce travail a conduit à développer un modèle reliant la taille de la phase dispersée aux principaux paramètres opératoires de chaque procédé, pour le cas rarement recensé dans la littérature, des mélanges de polymères de viscosités très différentes.La seconde partie a été consacrée à la conception et à la réalisation d’une installation constituée d’un pilote de polycondensation équipé, en sortie de réacteurs, d’un dispositif de mélange reposant sur la technologie des mélangeurs statiques. Son fonctionnement a ensuite été éprouvé pour les deux mélanges considérés, grâce des expériences qui ont permis d’analyser l’influence de différentes conditions opératoires sur la morphologie des mélanges générés. La comparaison des résultats obtenus à ceux issus des procédés conventionnels, a alors permis de préciser les performances et les limites du procédé développé dans cette étudeThe aim of this work is to develop a process, which enables to blend polyamide in molten state with others polymers, directly at the outlet of a polycondensation reactor. Contrary to currently industrial processes, no remelting stage is needed in this one. The study has been carried out with polyamide 66 / polyethylene glycol blends (products with very different viscosities) and with polyamide 66 / ethylene propylene blends (products with similar viscosities), with or without polypropylene-graft-maleic-anhydride as interfacial agent. The first part of this work deals with the characterization of the dispersions obtained for these blends when their elaborations are carried out using conventional processes. Only few studies are available on blends, which exhibit a large difference between components viscosity. This work led us to develop a model to correlate, in this case, the dispersed phase size to the main operating conditions of each processes.The second part is dedicated to the design and the realization of an experimental installation, which is composed of polycondensation plant equipped, at the outlet of reactors, with a blending device based on static mixers technology. Its operation has been tested and experiments have been carried out in order to study the influence of the different processing parameters on blends morphology. The comparison of the results with those previously obtained using conventional processes allowed then to precise the performances and the limits of the process developed in this study
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Gerard, Eric-Jack. "Synthese, caracterisation et comportement de polyurethannes hydrophiles : etude du mecanisme de la polycondensation reticulante." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13192.
Abstract:
Synthese d'hygrogels, constitues de chaines elastiques de polydioxolanne. Les reticulats sont synthetises en milieu organique par couplages multiples des extremites hydroxylees, du polydioxolanne precurseur avec un compose isocyanate plurifonctionnel. Apres reaction, un echange progressif du solvant organique par l'eau permet d'obtenir les hydrogels
10
Tran, Van-Thanh. "Mise au point de microparticules biodégradables en vue de la libération prolongée d'une protéine." Angers, 2010. http://www.theses.fr/2010ANGE0076.
Books on the topic "Pointe polymère":
1
Tieu, Doan. A dynamic optimization package and the application of an end-point collocation method to batch polymer reactors. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1992.
2
Granados, Manuel Laopez, and David Martin Alonso. Furfural: An Entry Point of Lignocellulosic Biomass to Renewable Chemicals, Polymers, and Biofuels. World Scientific Publishing Co Pte Ltd, 2018.
3
Luh, Song-ping. The cloud point composition and flory-huggins interaction parameters of polyethylene glycol and sodium lignin sulfonate in water-ethanol mixtures. 1987.
4
SIMON, Guilhem, ed. Spectroscopies vibrationnelles. Editions des archives contemporaines, 2020. http://dx.doi.org/10.17184/eac.9782813002556.
Abstract:
Les spectroscopies vibrationnelles sont des techniques de caractérisation optique très répandues et utilisées dans de nombreux domaines scientifiques et industriels. Elles bénéficient depuis plusieurs années d’un grand essor, de par les nombreuses innovations technologiques qui les rendent de plus en plus performantes et utilisables sur des nombreux matériaux (cristaux et céramiques, polymères, verres…), molécules (organiques et inorganiques), sous diverses formes (liquide, gaz ou solide), sur des milieux biologiques, naturels, et sur des objets du patrimoine culturel. Les temps de mesures sont désormais compatibles avec des process industriels et les échelles spatiales de mesures tendent vers la résolution nanométrique. Ce livre est un ouvrage collectif et collaboratif entre chercheurs universitaires, CNRS et industriels, utilisateurs de ces techniques et au service de ces spectroscopies. Il s'adresse à un public large et se propose de faire le point à la fois sur la théorie de la spectroscopie vibrationnelle, mais aussi sur la définition, les caractéristiques et la mise en oeuvre de ces diverses techniques à travers des exemples variés d'utilisation.
5
Gavrilenko, Vladimir I. Optics of Nanomaterials. Taylor & Francis Group, 2010.
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Gavrilenko, Vladimir I. Optics of Nanomaterials. Jenny Stanford Publishing, 2019.
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Gavrilenko, Vladimir I. Optics of Nanomaterials. Taylor & Francis Group, 2019.
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Gavrilenko, Vladimir I. The Optics of Nanomaterials. World Scientific Publishing Company, 2007.
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Epstein, Irving R., and John A. Pojman. An Introduction to Nonlinear Chemical Dynamics. Oxford University Press, 1998. http://dx.doi.org/10.1093/oso/9780195096705.001.0001.
Abstract:
Just a few decades ago, chemical oscillations were thought to be exotic reactions of only theoretical interest. Now known to govern an array of physical and biological processes, including the regulation of the heart, these oscillations are being studied by a diverse group across the sciences. This book is the first introduction to nonlinear chemical dynamics written specifically for chemists. It covers oscillating reactions, chaos, and chemical pattern formation, and includes numerous practical suggestions on reactor design, data analysis, and computer simulations. Assuming only an undergraduate knowledge of chemistry, the book is an ideal starting point for research in the field. The book begins with a brief history of nonlinear chemical dynamics and a review of the basic mathematics and chemistry. The authors then provide an extensive overview of nonlinear dynamics, starting with the flow reactor and moving on to a detailed discussion of chemical oscillators. Throughout the authors emphasize the chemical mechanistic basis for self-organization. The overview is followed by a series of chapters on more advanced topics, including complex oscillations, biological systems, polymers, interactions between fields and waves, and Turing patterns. Underscoring the hands-on nature of the material, the book concludes with a series of classroom-tested demonstrations and experiments appropriate for an undergraduate laboratory.
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Banerjee, Diptonil, Amit Kumar Sharma, and Nirmalya Sankar Das. Nano Materials Induced Removal of Textile Dyes from Waste Water. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/97898150502951220101.
Abstract:
Nanotechnology has progressed to the point where it can mimic natural systems such as porous membranes or the structure of leaves. Technological advances have resulted in a boom in the use of nanotechnology in different areas of engineering, including water purification systems. This book explores nanomaterials used for removing various textile dyes from water. It compiles 8 chapters that discuss the materials and nano systems used in these processes. This reference is designed to provide answers to common questions for scholars, academicians and technologists about fundamentals of nanoscience and nanomaterial induced removal of textile dyes. College students (physics, chemistry and materials science, engineering) will be able to easily understand the subject matter. Key Features: Covers the basics of nano systems, from synthesis to applications Explains the basics of nanomaterial behavior and characterization Describes the classifications of dyes Explains the interactions nanomaterials with different dyes Explains the reaction mechanisms of photocatalysis and the kinetics behind adsorption two important methods for removing dyes from water Discusses nano systems that are useful for textile dye removal from water. 3 types of nano systems are included: carbon based, oxide based, polymer based or nitride based systems Includes references for further reading Simple presentation for easy and quick understanding of the subject
Book chapters on the topic "Pointe polymère":
1
Gooch, Jan W. "Nodal Points." In Encyclopedic Dictionary of Polymers, 487. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_7929.
2
Gooch, Jan W. "Flash Points." In Encyclopedic Dictionary of Polymers, 310. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_5039.
3
Gooch, Jan W. "Brittle Point." In Encyclopedic Dictionary of Polymers, 94. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_1598.
4
Gooch, Jan W. "Clear Point." In Encyclopedic Dictionary of Polymers, 147. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_2441.
5
Gooch, Jan W. "Cloud Point." In Encyclopedic Dictionary of Polymers, 148. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_2467.
6
Gooch, Jan W. "Critical Point." In Encyclopedic Dictionary of Polymers, 179. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_3094.
7
Gooch, Jan W. "Curie Point." In Encyclopedic Dictionary of Polymers, 187. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_3197.
8
Gooch, Jan W. "Dew Point." In Encyclopedic Dictionary of Polymers, 203. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_3467.
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Gooch, Jan W. "Set Point." In Encyclopedic Dictionary of Polymers, 655. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10488.
10
Gooch, Jan W. "Silver Point." In Encyclopedic Dictionary of Polymers, 666. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10671.
Conference papers on the topic "Pointe polymère":
1
Shankar, Vivek, Shekhar Sunit, Robert Zagitov, Abhishek Kumar Gupta, Suresh Kumar, Ritesh Kumar, Kumarish Pahari, Rahul Agarwal, Petro Nakutnyy, and Santhosh Veerabhadrappa. "Evaluation of Alternative Polymers for Mangala Polymer Flood." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211461-ms.
Abstract:
Abstract Mangala field is under polymer-flood since 2015. The polymer-flood is very successful in accelerating recovery compared to waterflood. As the flood matured, field performance indicated that part of the injected polymer was degrading in the reservoir. Lab studies and polymer samples collected from the reservoir suggest that the most likely reason of degradation is increased hydrolysis due to thermal ageing. This degradation compels higher dosing of polymer to make up for the lost viscosity and increases operating costs. Polymer precipitation in the reservoir may also lead to loss of reservoir permeability. Literature survey and preliminary lab studies showed that polymers with Acrylamide-Tertiary-Butyl-Sulfonic acid monomer units (referred as ATBS polymers) could be a suitable option for Mangala. To evaluate the hypothesis, team did a series of lab and core flood studies. The studies include accelerated thermal ageing, rheology, dynamic adsorption, injectivity, water flood with fresh and degraded samples and compatibility studies with topside chemicals. Two HPAM polymers with different DOH and two ATBS polymers were evaluated. The selected ATBS polymer was then tested for compatibility with surface topside chemicals. The studies show that the classic 20-25% DOH HPAM suffers viscosity degradation and possible precipitation in Mangala reservoir conditions. ATBS polymers and a lower DOH HPAM provide superior results to the incumbent HPAM with an acrylamide (86)-ATBS (14) copolymer providing the best results. ATBS polymers were especially resistance to cloud point lowering and provide some superiority in shear degradation. ATBS monomer was resistant to hydrolysis in the period of testing. Contrary to published literature ATBS polymers showed higher adsorption and their propagation through cores required higher pressure drop. ATBS polymer seemed to plug a low permeability section of the core stack. All polymers reach their peak viscosity at 30-40% hydrolysis and decline sharply after 40%. However, viscosity and cloud points measured during accelerated ageing are possibly conservative. A large-scale pilot of ATBS injection in Mangala is underway to validate the laboratory test results. ATBS polymer can be a suitable polymer for some layers of Mangala with high residence time and permeability. The choice is driven by the economics of the incremental cost of ATBS for the benefits it offers. In some sands with shorter inter wells pacing, a lower DOH HPAM may work out to be a more cost-effective solution. The study results provide insights to operators to understand the reservoir performance of existing polymer-floods and plan for future polymer-floods.
2
Zhang, Yadong, Liming Wang, Tatsuo Wada, and Hiroyuki Sasabe. "Carbazole Main-Chain Polymers with Di-Acceptor-Substituents for Nonlinear Optics." In Organic Thin Films for Photonic Applications. Washington, D.C.: Optica Publishing Group, 1993. http://dx.doi.org/10.1364/otfa.1993.wd.8.
Abstract:
Polymeric second-order nonlinear optical (NLO) materials have been studied extensively in recent years for applications in electrooptic devices [1,2]. There are three types of polymer materials developed for this purpose: guest-host systems [3], side-chain polymers [4-6], and main-chain polymers [7-9]. The second-order NLO effects of these materials were demonstrated after electric poling above the polymer glass transition temperature (Tg). While many guest-host and side-chain NLO polymers have been developed, relatively few main-chain polymers have been prepared. Most of the main-chain polymers reported are heat-to tail; namely, all the Chromophore dipole moments point in the same direction along the polymer main chain.
3
Zeni, Luigi. "Surface plasmon resonance in polymer optical fibers for point of care analysis." In Biophotonics in Point-of-Care III, edited by Michael T. Canva, Ambra Giannetti, Julien Moreau, and Hatice Altug. SPIE, 2024. http://dx.doi.org/10.1117/12.3016714.
4
Gross, K. A., F. Y. Yan, C. C. Berndt, and G. P. Simon. "Repair of Multi-Layered, Polymer-Based Thermal Spray Coatings." In ITSC2005, edited by E. Lugscheider. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2005. http://dx.doi.org/10.31399/asm.cp.itsc2005p0074.
Abstract:
Abstract Polymeric coatings manufactured by thermal spray processes exhibit variable mechanical and adhesion properties that depend on their exact processing schedules. One important advantage of these coatings is that they can be readily repaired by re-spraying any delaminated or otherwise defective regions. In some instances the repaired region exhibits better mechanical attributes than the original coating. In this study the repairability of several classes of polymeric and polymer-ceramic composite coatings were investigated with a focus on the interfacial adhesion properties. The coatings include those of monolayer and bilayer ethylene methacrylic acid (EMAA), and CaCO3-EMAA composites. The coating thickness did not influence the interfacial adhesive strength between the coating and substrate; while a higher preheat temperature produced a greater interfacial cohesion for the monolayer coating on a metal substrate. The substrate preheat temperature played a dominant role concerning the peel strength of the coating. Greater peel strengths were achieved between polymers, at least twofold greater than that between the polymer and the steel substrate when the pre-heat temperature was greater than the melting point of the polymer. The peel strength of the composite coating decreased with filler content; both on the steel substrate and on a previously sprayed polymer coating. On the basis of these observations, the adhesion mechanism between polymers was explained with a model that relied on the formation of welding points.
5
Morozov, Yevhenii M., Nestor Gisbert Quilis, Fiona Diehl, Sven Klees, Jonas Grün, Ulrich Jonas, and Jakub Dostálek. "One- and two-photon crosslinked polymer hydrogel microstructures for optical spectroscopy and biosensing applications." In Biophotonics in Point-of-Care II, edited by Michael T. Canva, Ambra Giannetti, Julien Moreau, and Hatice Altug. SPIE, 2022. http://dx.doi.org/10.1117/12.2621516.
6
Hasler, Roger, Ivana Vísová, Markéta Vrabcová, Milan Houska, Monika Spasovová, Hana Lísalová, and Jakub Dostálek. "Fiber optic probe with antifouling polymer brush biointerface for bi-modal biosensing in complex liquid samples." In Biophotonics in Point-of-Care II, edited by Michael T. Canva, Ambra Giannetti, Julien Moreau, and Hatice Altug. SPIE, 2022. http://dx.doi.org/10.1117/12.2621192.
7
Seright, Randall Scott, and Dongmei Wang. "Impact of Salinity, Hardness, Lithology, and ATBS Content on HPAM Polymer Retention for the Milne Point Polymer Flood." In SPE Western Regional Meeting. SPE, 2023. http://dx.doi.org/10.2118/212946-ms.
Abstract:
Abstract At the Milne Point polymer flood (North Slope of Alaska), polymer retention is dominated by the clay, illite. Illite (and kaolinite) cause no delay in polymer propagation in Milne Point core material, but they reduce the effective polymer concentration and viscosity by a significant amount (e.g., 30%), thus reducing in efficiency of oil displacement until the full injected polymer concentration is regained (which requires several pore volumes of throughput). This work demonstrates that polymer retention on illite is not sensitive to monovalent ion concentration, but it increases significantly with increased divalent cation concentration. Incorporation of a small percentage of ATBS monomers into HPAM polymers is shown to dramatically reduce retention. Results are discussed in context with previous literature reports. Interestingly, an extensive literature review reveals that polymer retention is typically only modestly sensitive to the presence of oil. Extensive examination of literature on inaccessible pore volume suggests the parameter was commonly substantially overestimated, especially in rock/sand more permeable than 500 md (which comprises the vast majority of existing field polymer floods).
8
Maji, Debashis, and Soumen Das. "Simulation and feasibility study of flow sensor on flexible polymer for healthcare application." In 2013 IEEE Point-of-Care Healthcare Technologies (PHT). IEEE, 2013. http://dx.doi.org/10.1109/pht.2013.6461302.
9
Dennar, Linda, Mohammed Amro, and Sven Reichmann. "Polymer Selection for Enhanced Oil Recovery in a Niger-Delta Formation Via Laboratory Experiments." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/211928-ms.
Abstract:
Abstract Several Scholarly articles have been written on the efficacy of Local and Foreign Polymers as agents of mobility control in Enhanced Oil Recovery Systems. Polymers are Non-Newtonian Fluids that are significantly affected by the reservoir properties. The Polymer chemistry is strongly dependent on Temperature and Salinity of injection/formation water thus the need for laboratory investigations of compatibility. Polymer solutions also undergo losses through adsorption and entrapment during propagation within the reservoir and subsequently create poor sweep if this happens. This research has investigated the suitability of two Polymers in the Niger Delta Formation: Xanthan Gum which is a biopolymer and Polyacrylamide a Synthetic polymer. Using an Analogue core sample having similar properties with the "Case Study" and a 2.8g/l polymer concentration obtained via 3-Dimensional simulation model, a laboratory core flood experiment was performed. The essence of the flooding analysis was to investigate The Residual Resistant Factor associated with the polymer solutions which is also an indication of the property changes associated with the reservoir post flooding. The benefits and economic viability of Polymer slug sizes with the addition of CO2 (Polymer Alternating Gas-PAG) was also investigated. Unsteady State single-phase permeability The Resistance Factor for the reservoir Results from the 2.8g/l solution of Polyacrylamide flooding shows a favorable Residual Resistance Factor of 0.97 to 7.05. Indications from the results suggests that using smaller slug models would not be favorable for such deployments. Larger slug models yield better RRFs, while a combination of Larger Slugs + CO2 results in a more economic resource use as less polymer is deployed. 2.8g/l Xanthan solution though having good Rheology showed very high RRFs (75-124) suggesting a possibility of encountering injectivity issues. Further investigations will be required to ascertain the effects of reducing the concentration of Xanthan on the injectivity and generally on the recovery process. A good handle on the concentration and chemical suitability of polymers with the inherent reservoir properties is the starting point of an efficient deployment of polymers as mobility control agents.
10
de Mello, J. C. "Plastic electronics for point-of-care diagnostics." In IET Seminar on Polymer Electronics: Towards the Future. IET, 2009. http://dx.doi.org/10.1049/ic.2009.0064.
Reports on the topic "Pointe polymère":
1
Hayes, Michael. Introduction of Continuous Fiber-reinforced Polymer: A New Additive Manufacturing Path for Aerospace. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, August 2023. http://dx.doi.org/10.4271/epr2023019.
Abstract:
<div class="section abstract"><div class="htmlview paragraph">To grow the application space of polymer additive manufacturing (AM), the industry must provide an offering with improved mechanical properties. Several entities are working towards introducing continuous fibers embedded into either a thermoplastic or thermoset resin system. This approach can enable significant improvement in mechanical properties and could be what is needed to open new and exciting applications within the aerospace industry.</div><div class="htmlview paragraph"><b>Introduction of Continuous Fiber Reinforced Polymer: A New Additive Manufacturing Path for Aerospace</b> examines a couple of unsettled issues that are beginning to come to light regarding these materials and focuses on the ability to design and provide robust structural analysis for continuous fiber reinforced polymer AM—unsung aspects that can make or break this new technology as it finds its way into the aerospace market. Without solutions to them, adoption by the aerospace industry will be limited to point design applications, thus constraining the technology to being nothing more than a specialized tool.</div><div class="htmlview paragraph"><a href="https://www.sae.org/publications/edge-research-reports" target="_blank">Click here to access the full SAE EDGE</a><sup>TM</sup><a href="https://www.sae.org/publications/edge-research-reports" target="_blank"> Research Report portfolio.</a></div></div>
2
Committee on Toxicology. New Approach Methodologies (NAMs) In Regulatory Risk Assessment Workshop Report 2020- Exploring Dose Response. Food Standards Agency, March 2024. http://dx.doi.org/10.46756/sci.fsa.cha679.
Abstract:
The UK Food Standards Agency (FSA) and the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) held an “Exploring Dose Response” workshop in a multidisciplinary setting inviting regulatory agencies, government bodies, academia and industry. The workshop provided a platform from which to address and enable expert discussions on the latest in silico prediction models, new approach methodologies (NAMs), physiologically based pharmacokinetics (PBPK), future methodologies, integrated approaches to testing and assessment (IATA) as well as methodology validation. Using a series of presentations from external experts and case study (plastic particles, polymers, tropane alkaloids, selective androgen receptor modulators) discussions, the workshop outlined and explored an approach that is fit for purpose applied to future human health risk assessment in the context of food safety. Furthermore, possible future research opportunities were explored to establish points of departure (PODs) using non-animal alternative models and to improve the use of exposure metrics in risk assessment.
3
Acosta, Felipe, and Guillermo Riveros. Repair of corroded steel girders of hydraulic steel structures (HSS) using fiber-reinforced polymers (FRP). Engineer Research and Development Center (U.S.), August 2023. http://dx.doi.org/10.21079/11681/47404.
Abstract:
Although steel hydraulic structures have a protective system to prevent corrosion, this type of deterioration will eventually occur due to the constant exposure to harsh environmental conditions. There are several techniques that can be implemented to repair corroded steel structural elements. This report presents a numerical study to evaluate the mechanical behavior of corroded steel girders used in hydraulic steel structures and to evaluate several carbon fiber–reinforced polymers (CFRP) layups to repair them. The girders were modeled as simply supported with four-point loading boundary conditions. The corrosion deterioration was modeled as loss in section as 10%, 25%, and 40%. The effectiveness of the deterioration was established based on the level of stresses at the steel compared with the undamaged condition after it is strengthened with CFRP. It was found that CFRP repair is more practical for reducing the stresses at the steel in the shear dominated zone if deterioration is below 25%. At the tensile dominated zone, CFRP is effective for reducing the stresses for deterioration below 40%.