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Étude multi-échelle des variations structurales, géochimiques et des propriétés magnétiques des coulées basaltiques prismées : exemple de la coulée de La Palisse (Ardèche) et de Saint-Arcons-d’Allier (Haute-Loire) / Multi-scale study of structural, geochemical and magnetic properties variations in columnar basalt flows : example of the La Palisse (Ardèche) and Saint-Arcons-d’Allier (Haute-Loire) basalt flows.Boiron, Tiphaine 12 October 2011 (has links)
Des structures prismées sont fréquemment observées dans les coulées de lave comme la Chaussée des Géants (Irlande). Plusieurs théories existent pour expliquer ces formations, dont la plus répandue est celle de la contraction thermique. Or cette théorie permet difficilement de comprendre certaines observations de terrain comme la séparation fréquente des coulées en plusieurs niveaux. Afin de mieux comprendre la structuration au sein des coulées basaltiques, nous avons procédé à une étude pluridisciplinaire basée sur les propriétés magnétiques, les variations structurales et géochimiques de deux coulées prismées du Massif Central (La Palisse, Ardèche et Saint-Arcons-d’Allier, Haute-Loire). Notre approche permet de montrer que les fabriques cristallographiques et magnétiques sont gouvernées par l’écoulement de la lave. L’orientation du plagioclase contrôle la distribution des titanomagnétites à l’origine des fabriques magnétiques. Notre étude montre également que l’utilisation de l’ASM est un outil fiable pour déterminer l’orientation de l’écoulement à condition d’être contrôlée par des mesures de fabriques cristallographiques. Les mesures de la quantité d’eau et les analyses isotopiques (H et O) montrent que l’effet de l’altération météorique est faible et que l’eau contenue dans la roche est essentiellement de l'eau de constitution. De plus, à l’échelle du prisme, des variations de deuxième ordre sont observées comme celle des paramètres d’hystérésis qui indique des tailles de grains de titanomagnétites plus importantes vers le centre. Ces variations au sein du prisme semblent difficilement compatibles avec une structuration des coulées par la simple contraction thermique. / Columnar jointing is frequently observed in lava flows, as in the Giant Causeway (Ireland). The most common theory explaining the formation of prisms is by the thermal contraction. However, this theory hardly explains some field observations such as the frequent existence of three parts within the lavas flows, from the base to the top. To complete our understanding of the structuring lava flows, we carried out a multidisciplinary study based on the magnetic properties, structural and geochemical characterization of two basaltic flows from the French Massif Central (La Palisse, Ardèche and Saint-Arcons-d'Allier, Haute-Loire). Our approach shows that crystallographic and magnetic fabrics are governed by the flow. The distribution of titanomagnetite grains carrying the magnetic fabrics is mainly controlled by the plagioclase orientation. Our study also shows that the use of the AMS to determine the flow direction is a reliable tool, provided punctual control by measurements of crystallographic fabrics are performed. Measurements of the water content and isotopic analyses (H and O) show a limited weathering effect in the studied areas: rock water is mostly primary water in equilibrium with the magma. Moreover, second order changes are noted across the prism section such as hysteresis parameters associated to grain size variation of titanomagnetite (larger grains in the center). The variations of magnetic properties across the prism section suggest a gradient of the crystallization rate from the center to the edge of the prism, which seems difficult to reconcile with the structuring of the flow by thermal contraction only.
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Estudo do comportamento mecânico de cilindros de compósito epóxi/fibra de basalto em ensaios hidrostáticos / Study of mechanical behavior of epoxy/basalt fiber composite cylinders under hydrostatic testsLapena, Mauro Henrique 26 January 2017 (has links)
O objetivo deste trabalho foi estudar o comportamento mecânico de cilindros de compósito polimérico reforçado com fibras. Para isso, foram produzidos cilindros com extremidades abertas reforçados com fibra de basalto e fibra de vidro, utilizando a técnica de enrolamento filamentar (filament winding). Estes cilindros foram submetidos a ensaio hidrostático com carregamento circunferencial, ensaio de ruptura de anel (split disk test) e ensaio de resistência ao cisalhamento interlaminar (ILSS). Uma placa do compósito de fibra de basalto foi produzida por enrolamento filamentar, para caracterização por ensaio de resistência à tração. Todos cilindros submetidos ao ensaio hidrostático apresentaram fratura localizada em uma faixa de altura do cilindro, com extensas delaminações das camadas circunferenciais. Os compósitos epóxi/fibra de basalto superaram ou igualaram os de compósito epóxi/fibra de vidro nas comparações entre resultados dos valores das propriedades mecânicas avaliadas, nas porcentagens: resistência à tração aparente de ruptura de anel em 45% e 43% em resistência específica; ILSS, em 11%; resistência/tensão de membrana de ruptura no ensaio hidrostático, em 55%. / The aim of this work was to study the mechanical behavior of fiber reinforced polymer composite cylinders. For this purpose, cylinders reinforced with basalt and glass fibers were produced, with open-ended geometry, using filament winding technique. These cylinders were submitted to hydrostatic test under circunferential loading, split disk (ring segment) test and interlaminar shear strength (ILSS). A basalt fiber composite plate was produced by filament winding for characterization by tensile strength test. All cylinders submitted to hydrostatic test presented fracture located in the height range of the cylinder, with extensive delamination of the circumferential layers. The epoxy/basalt fiber composites overcame or equated the epoxy/glass fiber composites in comparisons between results of the mechanical properties, tensile strength in split disk, in 45% and 43% in specific strength; ILSS in 11%; membrane tensile strength in the hydrostatic test, in 55%.
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Propuesta de mejora de la carpeta asfáltica por medio de fibras de basalto y lignina, para el control de deformaciones permanentes en carreteras sometidas a carga vehicular pesada y altas temperaturas / Proposal to improve the asphalt layer by means of basalt and lignin fibers, for the control of permanent deformations on roads subjected to heavy vehicular load and high temperaturesFarfan Gonzales, Fabrizio Jesus, Huaquía Díaz, José Luis 30 August 2021 (has links)
La deformación permanente es una de las principales responsables del deterioro temprano de la capa asfáltica de carreteras. Este tipo de fenómeno, se ve impulsado en el país debido a la carga vehicular pesada y la variedad climática, en particular, las altas temperaturas. Se sabe que el comportamiento de la mezcla asfáltica, depende directamente de los materiales que la constituyen. Y ante condiciones desafiantes, estos materiales son insuficientes.
En ese sentido, la presente investigación busca mejorar las propiedades de una mezcla asfáltica convencional mediante la adición de fibras de basalto y lignina, de tal manera que sea menos propensa a sufrir deformaciones permanentes.
Para la parte experimental, se contó con agregados procedentes de la cantera Conchán, en Lima. Mediante la metodología de Marshall, se diseñaron dos mezclas asfálticas. La primera mezcla fue elaborada sin aditivos y en base a expedientes técnicos de la zona. La segunda mezcla se elaboró con los mismos componentes y con adición de 0.3% fibras de basalto y 0.3% de fibras de lignina. Las muestras fueron sometidas a ensayos de estabilidad y flujo, índice de rigidez, vacíos de agregado mineral y resistencia a la compresión.
Los resultados de la investigación mostraron que al incorporar fibras de basalto y fibras de lignina se aumentan la estabilidad de la mezcla en 7%, el índice de rigidez de Marshall en 6%, el porcentaje de vacíos de agregado mineral en 2% y la resistencia a compresión en 4%. De lo anterior de infiere que la mezcla asfáltica propuesta tiene una mayor capacidad para distribuir la carga, mayor resistencia a la deformación por fluencia, mayor capacidad de expansión para contrarrestar las altas temperatura y, en consecuencia, mayor resistencia a las deformaciones permanentes. / Permanent deformation is one of the main causes of the early deterioration of the asphalt layer of roads. This type of phenomenon is driven in the country due to the heavy vehicle load and the climatic variety, in particular, the high temperatures. It is known that the behavior of the asphalt mixture depends directly on the materials that make it up. And in challenging conditions, these materials are insufficient.
In this sense, the present research seeks to improve the properties of a conventional asphalt mixture by adding basalt and lignin fibers, in such a way that it is less prone to permanent deformation.
For the experimental part, it was used aggregates from the Conchán quarry, in Lima. Using Marshall's methodology, two asphalt mixes were designed. The first mixture was made without additives and based on technical files in the area. The second mixture was made with the same components and with the addition of 0.3% basalt fibers and 0.3% lignin fibers. The samples were subjected to stability and flow tests, stiffness index, mineral aggregate voids and compressive strength.
The results of the investigation showed that when incorporating basalt fibers and lignin fibers the stability of the mixture is obtained in 7%, the Marshall stiffness index in 6%, the percentage of voids of mineral aggregate in 2% and the resistance a compression in 4%. From the foregoing, it can be inferred that the proposed asphalt mix has a greater capacity to distribute the load, greater resistance to creep deformation, greater expansion capacity to counteract high temperatures and, consequently, greater resistance to permanent deformations. / Tesis
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Nízkoteplotní zkoušky a lomová houževnatost vybraných keramických materiálů / Low temperature tests and fracture toughness of selected ceramic materialsBeck, Branislav January 2015 (has links)
Diploma thesis deals with the determination of fracture toughness values of sintered silicon carbide and casted basalt using both the Single Edge V-Notch Beam (SEVNB) and the Chevron Notched Beam (CNB) methods at room and cryogenic temperatures. The first part of this thesis offers general overview and categorization of ceramic materials. Fracture mechanics of the ceramic materials and available fracture toughness testing methods are discussed in following chapters. The last section in the theoretical part is aimed to the microstructure and properties of the silicon carbide. Experimental part of the work summarizes methods used for characterization of selected materials from the microstructural and fracture point of view. Preparation of samples for microstructural observation and samples for fracture toughness determination are described in details. The results of the fracture toughness data for sintered silicon carbide and cast-basalt obtained at room temperature and at -100 °C are displayed. Consideration of possible measurements errors and application of various fracture toughness testing methods are discussed in the next chapter of this work. The difference in the fracture toughness values with the decrease of testing temperature was found. The difference depends on both, the used method of fracture toughness determination and the material used for the tests. The most important results gained during the experimental work are summarized in the chapter “Conclusions”.
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Vliv anorganických vláken na fyzikálně mechanické vlastnosti cihlářského střepu / The effect of fibres addition on the properties of brick bodyNovotný, David January 2017 (has links)
This diploma thesis will discuss possibilities of using inorganic fibers to improve the mechanical properties of the resulting physical body bricks. Assessment of the effect of fiber length, fiber thickness is in the order of micrometers. In this work we were used fibers which are commercially produced for the purpose of reinforcement, but also waste fibers, which mainly serves as an insulator.
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Propuesta de diseño de concreto permeable reforzado con fibras de basalto (18mm, l7 µm) para mejorar su desempeño aplicado en pavimentos urbanosChallco Estrada, Bianca Francesca, Tuesta Gonzales Zúñiga ,Lea Rebeca 27 January 2021 (has links)
El crecimiento acelerado de las urbes y el uso de materiales impermeables han impactado negativamente en el ciclo hidrológico. Las fuertes precipitaciones durante la época de lluvias generan el colapso de redes de alcantarillado en ciudades con la infraestructura inadecuada. Dicha escorrentía acelera el deterioro de los pavimentos, además de la incomodidad y peligro debido al hidroplaneo que impacta en los peatones. El concreto permeable es un material adecuado para mitigar estos problemas debido a su propiedad de discurrir el agua entre sus poros, además de ser ecológico y sostenible. Ya que su resistencia es menor a la del concreto convencional, su uso es limitado en pavimentos rígidos, por ello la incorporación de fibras le proporcionaría un mejor desempeño mecánico. Mediante un análisis cualitativo de diversos factores, se determinó que las fibras de basalto optimizarían el comportamiento del concreto permeable para su aplicación en pavimentos urbanos. Además, se tomó en consideración que el suelo del área de estudio es de grava y la infiltración requerida es de 192.22mm/h. El diseño de mezcla de referencia corresponde a similares características con el área de estudio y finalmente las cantidades requeridas en el diseño de esta investigación son 443.12 kg/m3 de cemento, 130.43 l/m3 de agua, 135.16 kg/m3 de agregado fino, 1312.04 kg/m3 de agregado grueso, 3.99 kg/m3 de aditivo superplastificante; añadido a fibras de basalto en porcentajes de 0%, 0.1%, 0.2% y 0.3% respecto del diseño de mezcla. / The accelerated growth of cities and the use of waterproof materials have negatively impacted the hydrological cycle. Heavy rainfall during the rainy season leads to the collapse of sewerage networks in cities with inadequate infrastructure. Such runoff accelerates the deterioration of pavements, in addition to the discomfort and danger due to hydroplaning that impacts pedestrians. Pervious concrete is a suitable material to mitigate these problems due to its property of running water through its pores, in addition to being ecological and sustainable. Since its resistance is less than that of conventional concrete, its use is limited in rigid pavements, therefore the incorporation of fibers would provide better mechanical performance. Through a qualitative analysis of various factors, it was determined that basalt fibers would optimize the behavior of pervious concrete for application in urban pavements. In addition, it was taken into consideration that the soil of the study area is gravel and the required infiltration is 192.22 mm/h. The reference mix design corresponds to similar characteristics with the study area and finally the quantities required in the design of this research are 443.12 kg/m3 of cement, 130.43 l / m3 of water, 135.16 kg/m3 of fine aggregate, 1312.04 kg/m3 of coarse aggregate, 3.99 kg/m3 of superplasticizer additive; added to basalt fibers in percentages of 0%, 0.1%, 0.2% and 0.3% with respect to the mix design. / Trabajo de investigación
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Geochemical stratigraphy of the Dooley rhyolite breccia and Tertiary basalts in the Dooley Mountain quadrangle, OregonWhitson, David Neale 01 January 1988 (has links)
The Dooley Rhyolite Breccia in northeast Oregon was erupted between 12 and 16 million years ago, from central vents and linear feeder dikes within the Dooley Mountain quadrangle. The peraluminous, high-silica rhyolites of the formation were erupted over an irregular highland of eroded pre-Tertiary metamorphic rocks locally overlain by intracanyon, Eocene Clarno-type basalt flow(s) . The Dooley Rhyolite Braccia is exposed in a tectonically disrupted, north-south trending graben across the Elkhorn Range. The formation is variable in thickness with maximum thickness exceeding 660 meters in the south and 600 meters in the north half of the quadrangle. Volumetrically the formation is dominated by block lava flows with lessor associated volcaniclastic and pyroclastic rocks. Although initial and waning phases of eruption of the formation produced ash-flow tuffs which extend well beyond the quadrangle boundaries, volcanism within the quadrangle appears to have been primarily effusive. At least nine geochemically distinct rhyolite subunits belonging to four related chemical groups have been identified in the formation stratigraphy which appear to represent unique eruptive episodes. Chronologic geochemical patterns within the formation are consistent with a petrogenetic model of repeated partial melting and eruption from multiple silicic magma chambers in an attenuated continental crust. Basalts correlative with the Powder River Basalt and the Strawberry Volcanics overlie the Dooley Rhyolite Braccia on the north flank of Dooley Mountain. Cale-alkaline basalts correlative with the Strawberry Volcanics are overlain by thoeliitic basalts of uncertain affinity on the south flank of the mountain. These basalt flows on respective flanks of the mountain were not continuous across the quadrangle. Rhyolitic volcanism in the Dooley Mountain quadrangle is contemporary with the strawberry Volcanics and the Picture Gorge Basalt of the Columbia River Basalt Group.
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Análisis experimental del fresado de materiales compuestos reforzados con fibra de basaltoNavarro Mas, María Dolores 29 November 2021 (has links)
[ES] Los materiales compuestos reforzados con fibra son ampliamente utilizados en diversos sectores, como el aeroespacial y el de automoción. Tras su conformado, estos materiales necesitan procesos de mecanizado para eliminar el material sobrante y facilitar la unión entre piezas. Debido a la naturaleza heterogénea y la anisotropía de estos materiales, su comportamiento ante el mecanizado es diferente que los metálicos. Las fibras abrasivas provocan un rápido desgaste de la herramienta y, además, la aparición del delaminado puede hacer necesario el reprocesado o rechazo de las piezas. El delaminado es un defecto que provoca la separación de capas del material compuesto y hace que la pieza presente un aspecto deshilachado en el borde mecanizado porque la herramienta dobla las fibras en vez de cortarlas, además de poder producir un daño superficial en la pieza.
En esta tesis se ha abordado el estudio experimental del fresado de materiales compuestos reforzados con fibra de basalto, en concreto, en la operación de contorneado. En el mecanizado de este material se ha estudiado el desgaste de la herramienta, el acabado superficial y el delaminado, analizando la influencia de los parámetros de corte (velocidad, avance y profundidad de pasada), y de las características del material compuesto (volumen y orientación de fibra). Con respecto al material de las fibras, casi todos los estudios existentes se han centrado en las fibras de carbono y de vidrio, no habiendo estudios con fibras de basalto, aunque este material es de origen natural y una buena alternativa a las fibras de vidrio. Con respecto al proceso de fresado, los estudios existentes en la bibliografía se han centrado más en la operación de ranurado que en la de contorneado.
Una parte fundamental de la tesis se ha centrado en el estudio del delaminado. Para ello se han definido y desarrollado los diferentes aspectos teóricos que caracterizan este defecto. Además, se han cuantificado los tipos de delaminado (Tipos I y II) mediante la definición y comparación de parámetros unidimensionales y de superficie, evaluando su evolución temporal. Los parámetros unidimensionales permiten evaluar la longitud de las fibras que sobresalen o dañan la superficie, mientras que los parámetros de superficie permiten cuantificar la densidad del delaminado.
Como complemento al estudio experimental, se han utilizado herramientas estadísticas (diseño de experimentos, ANOVA y modelos de regresión cuantílica) para estudiar el fresado de este tipo de materiales en relación a la rugosidad, el desgaste de la herramienta y el delaminado. / [CA] Els materials compostos reforçats amb fibra són àmpliament utilitzats en diversos sectors, com l'aeroespacial i el d'automoció. Després del seu conformat, aquests materials necessiten processos de mecanitzat per a eliminar el material sobrant i facilitar la unió entre peces. A causa de la naturalesa heterogènia i anisotropia d'aquests materials, el seu comportament davant el mecanitzat és diferent que els metàl·lics. Les fibres abrasives provoquen un ràpid desgast de l'eina i, a més, l'aparició de la delaminació pot fer necessari el reprocessament o rebuig de les peces. La delaminació és un defecte que provoca la separació de capes del material compost i fa que la peça presente un aspecte esfilagarsat en la vora mecanitzada perquè l'eina doblega les fibres en lloc de tallar-les, a més de poder produir un mal superficial en la peça.
En aquesta tesi s'ha abordat l'estudi experimental del fresat de materials compostos reforçats amb fibra de basalt, en concret, en l'operació de contornejat. En el mecanitzat d'aquest material s'ha estudiat el desgast de l'eina, l'acabat superficial i la delaminació, analitzant la influència dels paràmetres de tall (velocitat, avanç i profunditat de passada), i de les característiques del material compost (volum i orientació de fibra). Respecte al material de les fibres, quasi tots els estudis existents s'han centrat en les fibres de carboni i de vidre, no havent-hi estudis amb fibres de basalt, encara que aquest material és d'origen natural i una bona alternativa a les fibres de vidre. Respecte al procés de fresat, els estudis existents en la bibliografia s'han centrat més en l'operació de ranurat que en la de contornejat.
Una part fonamental de la tesi s'ha centrat en l'estudi de la delaminació. Per a això s'han definit i desenvolupat els diferents aspectes teòrics que caracteritzen aquest defecte. A més, s'han quantificat els tipus de delaminació (Tipus I i II) mitjançant la definició i comparació de paràmetres unidimensionals i de superfície, avaluant la seua evolució temporal. Els paràmetres unidimensionals permeten avaluar la longitud de les fibres que sobreïxen o danyen la superfície, mentre que els paràmetres de superfície permeten quantificar la densitat de la delaminació.
Com a complement a l'estudi experimental, s'han utilitzat eines estadístiques (disseny d'experiments, ANOVA i models de regressió quantílica) per estudiar el fresat d'aquesta mena de materials i predir alguns aspectes de la rugositat, el desgast de l'eina i la delaminació. / [EN] Fiber reinforced composites are widely used in diverse fields such as aeronautics and automotive. After their shaping, these materials require machining processes to remove excess material and facilitate joining between parts. Due to the heterogeneous nature and anisotropy of these materials, their behavior when being machined is different from metallic ones. Abrasive fibers trigger fast tool wear and delamination appearance can cause piece reprocessing or discard. Delamination is a defect which induces the separation of composite layers and makes the piece present a frayed appearance on the machined edge because the tool bends the fibers instead of cutting them, in addition to producing surface damage to the piece.
In this thesis, the experimental study of milling of basalt fiber reinforced composite materials has been approached, specifically, in edge trimming. In the machining of this material, tool wear, surface finish and delamination have been studied, analyzing the influence of cutting parameters (cutting speed, feed per tooth and depth of cut) and characteristics of the composite material (fiber volume fraction and fiber orientation). Regarding the fiber material, almost all existing studies have focused on carbon and glass fibers, there are no studies with basalt fibers, although this material is of natural origin and a good alternative to glass fibers. About the milling process, existing studies in the literature have focused more on the grooving operation than on the edge trimming operation.
A fundamental part of the thesis has focused on the study of delamination. To characterize this defect, different theoretical aspects have been defined and developed. Additionally, different types of delamination (types I and II) have been quantified through the definition and comparison of one-dimensional and surface parameters, evaluating their temporal evolution. One-dimensional parameters allow the evaluation of the length of the fibers that protrude or damage the surface, while the surface parameters allow the quantification of the density of delaminate.
As a complement to the experimental study, statistical tools (experiment design, ANOVA and quantile regression models) have been used to study the milling of this type of materials and predict certain roughness, tool wear, and delamination aspects. / Navarro Mas, MD. (2021). Análisis experimental del fresado de materiales compuestos reforzados con fibra de basalto [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/177645 / TESIS
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Eliminace negativních vlastností betonů vyvolaných použitím recyklovaného kameniva pomocí čedičových vláken / ELIMINATION OF NEGATIVE PROPERTIES OF CONCRETE INDUCED BY THE USE OF RECYCLED AGGREGATES USING BASALT FIBERSFittl, David January 2022 (has links)
The thesis summarises information about recycled aggregates and basalt fibres, their interaction in composite material such as concrete. It focuses on the potential deficiencies and properties of concrete due to the use of recycled aggregates and on the possibilities of their subsequent elimination of their negative impact by the use of basalt fibres. It characterizes individual raw materials and their interaction in concrete. It includes verification of the properties of the individual sub-components and the resulting concrete itself. An assessment is made of the impact of the use of recycled aggregates on the properties of concrete (compresive strength, static modulus of elasticity, residual flexure tensile strength and others). The thesis discusses the question of whether the same or similar mechanical properties of concrete can be achieved with natural and recycled aggregates using basalt reinforcing fibres. The work provides for the possibility of settlement the values of these concrete parameters by using basalt fibres as a dispersed reinforcement in concrete. The recycled aggregates come from concrete company JARO AS in the north of Norway, where this work was conducted with the financial support from Erasmus+ at The Arctic University of Norway - campus Narvik.
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Vývoj lepicí hmoty pro instalaci čedičových prvků na silikátový podklad v náročných expozičních podmínkách / Development of adhesive material for the installation of basalt elements on silicate foundations under severe exposure conditionsBergerová, Kamila January 2019 (has links)
The diploma thesis deals with research and subsequent development of a new adhesive material for the installation of nonabsorbent basalt elements on silicate foundations under severe exposure conditions. For commercially produced tile adhesives, only primary raw materials are used as fillers. The purpose of this work is to evaluate the possibility of utilization of secondary raw materials as fillers in the tile adhesive. The thesis is mainly focused on the durability of these materials after exposure to the aggressive environment.
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