Literatura académica sobre el tema "Aluminum (CZA)"
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Artículos de revistas sobre el tema "Aluminum (CZA)"
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Li, Yongsheng, Chunhuan Luo y Qingquan Su. "Performance of Cu/ZnO/Al2O3 Catalysts Prepared by Sol–Gel Methods on Methanol Steam Reforming". Energies 16, n.º 23 (27 de noviembre de 2023): 7803. http://dx.doi.org/10.3390/en16237803.
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Cu/ZnO/Al2O3 catalysts were prepared for online methanol steam reforming (MSR) using a conventional sol–gel method in this study. The optimal preparation conditions, including the calcination temperature, Cu loading, molar ratio of citric acid to metal ions (CA/M), and pH, were investigated. CZA50 exhibited the highest MSR activity among all catalysts. It was prepared at a calcination temperature of 350 °C; Cu, Zn, and Al molar fractions of 50%, 30%, and 20%; CA/M of 1.5; and without adjusting pH. Furthermore, a modified sol–gel method was proposed to enhance the mechanical strength of Cu/ZnO/Al2O3 catalysts by using γ-Al2O3 powders as catalyst precursors instead of aluminum nitrates. In this modified method, part of Cu2+ and Zn2+ ions were impregnated firstly on γ-Al2O3 powders, and then the remaining metal ions formed sol–gel with citric acid. MCZA-0.25 catalysts prepared by this modified method showed superior catalytic activity at an Al/(Cu+Zn) ratio of 0.25. The methanol conversion rates of CZA50, MCZA-025, and CZA-Commercial were 82.9%, 79.4%, and 74.7% at the temperature of 200 °C and methanol liquid phase space velocity (LHSV) of 1.0/h, respectively. The average crushing strength of CZA50, MCZA-0.25, and CZA-Commercial were measured as 28 N/cm, 37 N/cm, and 32 N/cm, respectively.
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Olaniyan, O. S., A. A. Olanipekun, D. A. Akeredolu, A. T. Bello y J. P. Olojede. "Determination of the Pozzolanicity of Cocoa Pod Ash at Different Temperatures". LAUTECH Journal of Civil and Environmental Studies 1, March 2018 (1 de marzo de 2018): 82–86. http://dx.doi.org/10.36108/laujoces/8102/10(0121).
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Pozzolans are siliceous or aluminous materials which possess little or no cementing property but chemically react with calcium hydroxide at ordinary temperature to form compounds possessing cementitious properties. There is paucity of information on the pozzolanicity of Cocoa Pod Ash (CPA). Hence, this study investigated the pozzolanicity of CPA. Cocoa pods were obtained from selected farms in Egba Odeda, Ogun State Nigeria. The Cocoa pods were washed, sundried and calcinated to ashes in a furnace between 600° C to 1000° C at Science Laboratory Technology Department, Federal Polytechnic Ilaro, Ogun State. Chemical analyses and X-ray Crystallography were carried out on the CPA to determine the types of oxides present and their varying percentages. The oxides were Silica (SiO,), Ferric (Fe,O,), combined percentages of Ferric and Aluminum oxides (Fe,O, and Al,O,), Calcium (CaO), Magnesium (MgO) and Sulphur (SO,). The moisture content and the Loss of Ignition (LOD) of the CPA samples were also determined.The oxides of Silicon, Ferric, Aluminium, Calcium and Magnesium oxide ranged between 6.39-8.00; 0.78 – 0.89; 1.74- 2,29; 7.15-8.42 and 4.38-5.16% respectively. Sulphur trioxide and LOI ranged 3.51- 3.78 and 27.2- 32.0%, respectively. The Xray crystallography showed that the total percentage composition of SiO, Al,O, and Fe,O, in CPA varied from 14.87-24.21%. The study showed that CPA did not satisfy the minimum 70% requirements stipulated by ASTM C618 (2005) for a pozzolan after the analysis of the oxides but it satisfied all the requirements for LOI, hence CPA is a weak pozzolan
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Walbridge, Scott, Denis Beaulieu y Federico M. Mazzolani. "Recent Development of Codes for Design of Aluminum Structures in Canada". Key Engineering Materials 710 (septiembre de 2016): 451–57. http://dx.doi.org/10.4028/www.scientific.net/kem.710.451.
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In 2011, a new chapter was added to the Canadian Highway Bridge Design Code (CAN/CSA S6) [1] enabling the design of aluminum bridge components and structures in Canada. In 2016, activities are well underway, which will result in significant modifications to the Canadian aluminum structures code: “Strength Design in Aluminum” (CAN/CSA S157) [2] and the Canadian code for welding of aluminum structures: “Welded Aluminum Construction” (CAN/CSA W59.2) [3]. This paper discusses the philosophies employed in the development and modernization of these design codes and highlights some of the major changes to these codes. In the case of CAN/CSA S6, the new aluminum chapter was basically written from scratch. However, a practical approach was employed of using material from existing codes, where appropriate (including CAN/CSA S157, the AASHTO Bridge Design Specification [4], the U.S. Aluminum Design Manual [5], and the Eurocode [6]), and organizing the chapter to resemble as closely as possible the chapter for steel bridge structures, so that designers would be relatively comfortable with the new material. In the case of CAN/CSA S157, a significant reorganization of the code contents will be occurring in the latest edition, in order to bring it closer to the Canadian steel structures code (CAN/CSA S16) [7] where possible, again to make the code more user friendly. In the case of the aluminum welding code (CAN/CSA W59.2), changes are being considered to allow the use of technologies such as friction stir welding (FSW) and post-weld treatments (e.g. peening, grinding) for improving fatigue performance. This work is being done with input from Canadian industry experts and academics, in consultation with international experts from the U.S. and Europe. It is expected that this work will lead to substantially improved design codes, resulting in significant benefits in terms of the economics and safety implications of designing aluminum structures in Canada.
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Costa, Joseane Dunga da, Jeane Cruz Portela, Phâmella Kalliny Pereira Farias, Francisco Ernesto Sobrinho, Carolina Malala Martins Souza, Thaís Cristina de Souza Lopes y Francisco Wellington Andrade Silva. "Characterization and Classification of Soils of the Terra da Esperança Settlement Project in Chapada do Apodi, Brazil". Journal of Agricultural Science 11, n.º 4 (15 de marzo de 2019): 235. http://dx.doi.org/10.5539/jas.v11n4p235.
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Soil characterization and pedological classification are essential to define its main potentials and restrictions. The objective of this work was to classify the morphological, physical, chemical, and pedological attributes of soils of the Terra da Esperança Settlement Project (TESP) in Chapada do Apodi, Brazil, and find the most sensitive attributes for distinguishing them using multivariate analysis. The research was carried out in the TESP, in the municipality of Governor Dix-Sept Rosado, state of Rio Grande do Norte, Brazil. Ten sites were chosen to open representative soil profiles: Native Forest Area 1 (NFA1), 2 (NFA2), and 3 (NFA3), Collective Area with Native Forest (CNF), Agroecological Area (AEA), Cashew crop Area (CCA) Collective Area with Pasture 1 (CAP1), and 2 (CAP2), Permanent Preservation Area (PPA), and Cajaraneira (Spondia sp.) Orchard Area (COA). Disturbed and undisturbed soil samples were collected and subjected to physical and chemical analysis for soil classification. The soils classes found were: Cambissolo Haplico Carbonatico vertissolico (NFA1), Cambissolo Haplico Carbonatico tipico (CNF, and AEA), Cambissolo Haplico Ta Eutrofico tipico (CAP2, NFA2, and COA), Cambissolo Haplico Ta Eutrofico vertissolico (NFA3), Argissolo Vermelho Distrofico latossolico (CCA), Chernossolo Rendzico Ortico saprolitico (CAP1), and Neossolo Fluvico Ta Eutrofico tipico (PPA). The material of origin of the soils contributed to the presence of a calcic horizon in the profiles NFA1, CNF, AEA, CCA (Cambissolos), and CAP1 (Chernossolos). The textural class of the soils varied from sand to clay. The Argissolo (CCA) presented acid character, high aluminum saturation, low base saturation, dystrophic character, and low cation exchange capacity, forming horizons with chemical limitations, due to its latossolico character. The most sensitive attributes for distinguishing the soil classes were related to the source material, which directly influenced the soil physical (silt and clay) and chemical (acidity, salinity, nutrient availability, and clay activity) attributes.
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Saidy, A. R., A. Haris, M. Septiana, B. J. Priatmadi, H. Ifansyah y M. Mahbub. "The improvement of available phosphorous of reclaimed-mining soils with coal fly ash and empty fruit bunches of oil palm treatments". IOP Conference Series: Earth and Environmental Science 1377, n.º 1 (1 de julio de 2024): 012115. http://dx.doi.org/10.1088/1755-1315/1377/1/012115.
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Abstract Reclaimed-mining soil (RMS) were categorized as having an acidic pH, low organic carbon (C), low available phosphorous (P), and high contents of aluminium (Al) and iron (Fe); therefore, soil ameliorants were essentially added to this soil for improving soil fertility. The purpose of the research was to measure the impact of combining empty fruit bunches of oil palm (EFBOP) and coal fly ash (CFA) on the available P of RMS. Three rates of CFA application: 0, 75, and 150 Mg ha−1 and three rates of EFBOP application: 0, 25, and 50 Mg ha−1 were organized using a completely randomized design. A 1000 g of soil was placed to an experimental pot, and then CFA and EFBOP according to the treatment were added to the pot. The mixture of soils, CFA, and EFBOP were homogenized, and then incubated at 70% water holding capacity for 45 days. Available P, total P, Al-P, Fe-P, soil pH, and exchangeable Al were quantifies following the completion of incubation period. The findings of this research indicated that available P rose from 3 mg kg−1 of control (soil without treatment) to 5-41 mg kg−1 of soils with different amounts of CFA and EFBOP addition. The application of CFA and EFBOP also resulted in increases in soil pH from 4.33 in the control to pH 4.48-6.23. Additionally, the levels of Al-P, Fe-P, and exchangeable aluminum decreased with the application of CFA and EFBOP. The findings of this study highlight the potency utilizing industrial and agricultural wastes as soil ameliorants for improving available P to support plant growth on the reclaimed-mining soils.
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Liu, Yang. "Thermal enhancement of the oxidation layer of micron-sized aluminum powder and its anti-oxidation performance". Cambridge Science Advance 2024, n.º 1 (27 de enero de 2024): 43–54. http://dx.doi.org/10.62852/csa/2024/5.
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Micron-sized aluminum powder, with its typical core-shell structure, exhibits oxidation behavior upon slow heating in an oxidative atmosphere that is related to the particle size of the aluminum powder. A particle size-dependent thermal response mechanism for micron-sized aluminum powder is established: a "shell-breaking eruption" thermal response mechanism. The oxide layer is thermally enhanced, and the anti-oxidation reaction behavior mechanism of the enhanced samples is studied. Aluminum powder samples, heated slowly to specific temperatures to obtain changes in the oxide layer structure, are analyzed using a thermal analyzer to compare the slow heating response behavior of aluminum powder before and after the oxidation layer changes. It was found that after thermal enhancement of the aluminum powder oxidation layer, which changed from amorphous to γ-phase and whose thickness increased to twice the original thickness, the slow oxidation process of micron-sized aluminum powder was inhibited, and the aluminum powder was completely deactivated in the slow heating response.
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Kissell, J. Randolph. "Recent Developments in North American Aluminum Structural Design Codes". Key Engineering Materials 710 (septiembre de 2016): 427–32. http://dx.doi.org/10.4028/www.scientific.net/kem.710.427.
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Since INALCO 2013, the two main North American aluminum structural design codes – the Canadian Standards Association’s (CSA) S157 Strength Design in Aluminum and the Aluminum Association’s Specification for Aluminum Structures – have undergone significant changes. S157’s 2015 edition is the first significant revision of the Canadian aluminum structural standard since 2005, and the 2015 update of the Specification for Aluminum Structures is the first since 2010. This paper addresses the specific changes and their trends, viewed from a larger perspective to anticipate the future direction of these codes.
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Pham Thi Mai Huong y Nguyen Thi Huong. "Study ability of protection effect of organic acids for multi-metallic anti-corrosion additive system in ethylene glycol-water coolants". Vietnam Journal of Science and Technology 62, n.º 1 (23 de febrero de 2024): 48–57. http://dx.doi.org/10.15625/2525-2518/17071.
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In this work, the electrochemical behavior of carbon steel, brass, bronze and aluminum alloys in the presence of various important organic acids (sebacic acid (SbA), terephthalic (TPA), 2-ethylhexanoic (E2C6A), and octanoic (C8A)) and the effect that these have on the growth and protectiveness of the alloys have been investigated. The results show that the presence of organic acids in the coolant increases the protective effect of the system by forming a film on the surface of the alloys. The EIS impedance results demonstrate the formation of active and passive protective layers on the surface of the alloys. The results of surveying 04 types of organic acids for the protection of different alloy substrates show that TPA and SbA acid additives are more effective than C8A and E2C5A. The additive C8A not only did not inhibit corrosion but also promoted this process strongly, especially with aluminum alloys and the TPA has the best anti-corrosion effect for steel, followed by C1 copper alloy and aluminum.
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Mold, Cottle, King y Exley. "Intracellular Aluminium in Inflammatory and Glial Cells in Cerebral Amyloid Angiopathy: A Case Report". International Journal of Environmental Research and Public Health 16, n.º 8 (24 de abril de 2019): 1459. http://dx.doi.org/10.3390/ijerph16081459.
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(1) Introduction: In 2006, we reported on very high levels of aluminium in brain tissue in an unusual case of cerebral amyloid angiopathy (CAA). The individual concerned had been exposed to extremely high levels of aluminium in their potable water due to a notorious pollution incident in Camelford, Cornwall, in the United Kingdom. The recent development of aluminium-specific fluorescence microscopy has now allowed for the location of aluminium in this brain to be identified. (2) Case Summary: We used aluminium-specific fluorescence microscopy in parallel with Congo red staining and polarised light to identify the location of aluminium and amyloid in brain tissue from an individual who had died from a rare and unusual case of CAA. Aluminium was almost exclusively intracellular and predominantly in inflammatory and glial cells including microglia, astrocytes, lymphocytes and cells lining the choroid plexus. Complementary staining with Congo red demonstrated that aluminium and amyloid were not co-located in these tissues. (3) Discussion: The observation of predominantly intracellular aluminium in these tissues was novel and something similar has only previously been observed in cases of autism. The results suggest a strong inflammatory component in this case and support a role for aluminium in this rare and unusual case of CAA.
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Begen, Deniz, Gokce Calis-Ismetoglu, Omer Yunus Gumus y Halil Ibrahim Unal. "A comparative study of coal fly and bottom ashes as sustainable electroactive vibration damping materials". Environmental Engineering Research 29, n.º 4 (22 de noviembre de 2023): 230561–0. http://dx.doi.org/10.4491/eer.2023.561.
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Coal is used in most of the power and chemical plants to meet energy needs which produce various waste ashes. Reuse of these ashes as electroactive materials has great importance for sustainable development. In this study, it was detected that the main components of coal fly (CFA) and bottom ashes (CBA) were oxides of silica (SiO<sub>2</sub>), iron (Fe<sub>2</sub>O<sub>3</sub>), aluminium (Al<sub>2</sub>O<sub>3</sub>), and magnesium (MgO), besides carbon. These are well-known electrorheological (ER) active materials. The aim of this study is to reveal dielectric and electroactive vibration damping capabilities of CFA and CBA. According to the dielectric and ER flow tests carried out in insulating silicone oil (SO), the optimum concentration of particles was determined to be 35 wt.% for both ashes. Higher ER yield stress (τ<sub>y</sub> = 135 Pa), higher ER efficiency (32.8), and better viscoelastic properties (τ<sub>c</sub> = 128 Pa, G' = 680 kPa) under 3.0 kV mm<sup>-1</sup> applied electric field were obtained for 35CFA/SO suspension system compared to 35CBA/SO (τ<sub>y</sub> = 125 Pa, ER<sub>eff</sub> = 24.0, τ<sub>c</sub> = 55 Pa, G' = 260 kPa). Although it was concluded that both ashes can be upcycled to sustainable and smart vibration damping alternative materials, better performance was observed for CFA particles.
Tesis sobre el tema "Aluminum (CZA)"
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Duran, Martinez Laura Elizabeth. "Dévelοppement et οptimisatiοn d'un prοcédé de prοductiοn de mοlécules d'intérêt par hydrοgénatiοn du CΟ2 à partir d'hydrοgène renοuvelable". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMIR21.
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La transition des combustibles fossiles vers les sources d’énergie renouvelables est de plus en plus urgente en raison de leur contribution significative au changement climatique mondial. L'augmentation des niveaux de dioxyde de carbone dans l'atmosphère souligne le besoin critique d'alternatives durables. La conversion du CO₂ en molécules à valeur ajoutée (vecteurs énergétiques) offre une solution prometteuse pour réduire la dépendance aux combustibles fossiles. Cette thèse explore le potentiel de l'hydrogénation catalytique du CO₂ pour produire des produits chimiques à valeur ajoutée tels que le méthane, le méthanol et le di-méthyl éther (DME). Ces procédés offrent non seulement un moyen de réduire les émissions de CO₂, mais également une voie vers une production de carburant durable. La recherche explore divers processus catalytiques, en mettant particulièrement l'accent sur la catalyse thermique en raison de son efficacité supérieure et de sa pertinence pour une mise en œuvre industrielle. L'hydrogénation du CO₂ en une seule étape pour produire du DME est le cas étudié. Des expériences préliminaires ont été menées dans un réacteur à lit fixe de laboratoire pour mieux comprendre la performance des catalyseurs. Différents catalyseurs ont été testés pour la synthèse du DME. Étant donné que les réactions impliquées dans l'hydrogénation du CO₂ pour produire du DME comprennent la synthèse du méthanol à partir de CO₂ suivie de la déshydratation du méthanol, un mélange de catalyseurs a été réalisé pour la synthèse directe du DME. Pour le mélange de poudres, deux catalyseurs CuO/ZnO/Al₂O₃ (CZA), l'un commercial et l'autre développé, ont été testés pour la synthèse du méthanol, et deux zéolites CZA (HY et HZSM-5) ont été testées pour la déshydratation du méthanol. Le mélange physique de CZA-C avec HZSM-5 a été choisi pour une analyse plus approfondie. L'effet de la température, de la pression, du rapport molaire d'alimentation (H₂/CO₂) et de la vitesse spatiale horaire des gaz (GHSV) ont été évalués pour le développement de la cinétique de la synthèse du DME. Un modèle cinétique de Langmuir-Hinshelwood pour la synthèse du méthanol a été proposé, ainsi qu'une nouvelle relation pour la déshydratation du méthanol en DME, car la réaction n'est pas à l'équilibre. Un réacteur à Profil Optimal de Température (POT) intégrant le modèle cinétique développé a été étudié pour un contrôle précis de la température afin de maximiser la conversion du CO₂. Les simulations et optimisations ont confirmé que des temps de séjour plus longs, en ajustant la masse des catalyseurs, sont plus efficaces pour une conversion plus élevée du CO₂. Un avantage minimal (<1%) a été identifié en termes de conversion du CO₂ pour le réacteur POT par rapport à un réacteur isotherme. Cependant, la productivité combinée de DME et de méthanol a montré une meilleure performance (>4,4%) par rapport au réacteur isotherme. Un réacteur multitubulaire POT avec température de refroidissement variable, comprenant 958 tubes, a atteint une conversion du CO₂ de 34,18 % et un taux de production combiné de méthanol et de DME de 30,84 mol.h⁻¹ par tube, approchant l'équilibre thermodynamique sans recirculationThe transition from fossil fuels to renewable energy sources is becoming increasingly urgent due to their significant contribution to global climate change. The rising levels of carbon dioxide in the atmosphere highlight the critical need for sustainable alternatives. Converting CO₂ into value-added molecules (energy carriers) offers a promising solution to reduce reliance on fossil fuels. This thesis explores the potential of the catalytic hydrogenation of CO₂ to produce value-added chemicals such as methane, methanol, and dimethyl ether (DME). These processes not only offer a means to reduce CO₂ emissions but also provide a path toward sustainable fuel production. The research explores various catalytic processes, with a particular emphasis on thermal catalysis due to its higher efficiency and suitability for industrial implementation. The one-step CO₂ hydrogenation to DME is the case of study. Preliminary experiments were conducted into a laboratory fixed bed reactor to better understand catalyst performance. Different catalysts were tested for DME synthesis. Since the reactions that take place into CO₂ hydrogenation to DME comprise the methanol synthesis from CO₂ followed by methanol dehydration, a mixture of catalysts was done for the direct DME synthesis. For the powder mixture, two different CuO/ZnO/Al₂O₃ (CZA) catalysts, one commercial and one developed, were tested for methanol synthesis and two CZA zeolites (HY and HZSM-5) were tested for methanol dehydration. The physical mixture of CZA-C plus HZSM-5 was chosen for further analysis. The effect of temperature, pressure, feed molar ratio (H₂/CO₂) and gas hourly space velocity (GHSV) were assessed for the development of the kinetics of DME synthesis. A Langmuir–Hinshelwood kinetic model for methanol synthesis was proposed, along with a novel relationship for methanol dehydration to DME, since the reaction is not at equilibrium. An Optimal Temperature Profile (OTP) reactor integrating the kinetic model developed was studied for precise temperature control to maximise CO₂ conversion. Simulations and optimisations confirmed that longer residence times by adjusting catalysts mass is more effective for higher CO₂ conversion. A minimal advantage (<1%) was identified in terms of CO₂ conversion for the OTP reactor over an isothermal reactor. However, the combined productivity of DME and methanol had a better performance (>4.4%) over the isothermal reactor. An OTP multi-tubular reactor with variable coolant temperature, comprising 958 tubes, achieved 34.18% CO₂ conversion and a combined methanol and DME production rate of 30.84 mol.h⁻¹ per tube, approaching to thermodynamic equilibrium without recirculation
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Kadok, Joris. "Le système binaire aluminium-iridium, du diagramme de phases aux surfaces atomiques". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0202/document.
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Un alliage métallique complexe (CMA) est un composé intermétallique dont la maille élémentaire est constituée d’un nombre important d’atomes formant bien souvent des aggrégats de haute symmétrie. De la complexité de ces composés peuvent découler des propriétés physico-chimiques intéressantes pour divers domaines d’application. Le système binaire aluminium-iridium est un système qui présente de nombreux composés intermétalliques dont la moitié sont des CMA. Malgré l’étude approfondie dont ce système a fait l’objet dans la littérature, certaines incertitudes demeuraient irrésolues, nous amenant ainsi à réexaminer le diagramme de phase Al-Ir. Nous avons également exploré les systèmes ternaires dits "push-pull" Al-Au-Ir et Al-Ag-Ir, propices à la formation de phases CMA selon certains auteurs. Au total, une centaine d’échantillons ont été préparés par fusion à l’arc puis analysés par diverses techniques de caractérisations: diffraction des rayons X (XRD), microscopie électronique à balayage (SEM), analyse dispersive en énergie (EDS) et analyse thermique différentielle (DTA). Quatre nouveaux composés intermétalliques ont ainsi été identifiés: Al2.4Ir, Al72Au2.5Ir29.5, Al3AuIr et Al11SiIr6, ce dernier étant issu d’une manipulation accidentelle. La structure cristallographique de chacun de ces composés a été résolue, révélant Al2.4Ir et Al72Au2.5Ir29.5 comme étant des CMA possédant une centaine d’atomes dans la maille. Des calculs basés sur la théorie de la fonctionnelle de la densité (DFT) sont venus apporter des précisions concernant la stabilité des composés Al3AuIr et Al11SiIr6. Pour le système Al-Ir, une variante structurale de deux CMA déjà connus de la littérature a également pu être mise en évidence. Les structures cristallographiques de la variante de Al2.75Ir et de celle de Al28Ir9 ont ainsi été approchées, présentant 240 et 444 atomes dans leur maille respective. Les propriétés de surface comptent parmi les aspects les plus intéressants des CMA, par exemple pour la catalyse hétérogène. En l’absence de monocristaux de taille macroscopique, nous avons étudié la possibilité de former des composés de surface par dépôt de Ir sur une surface Al(100) suivi de recuits. Des caractérisations par diffraction d’électrons lents (LEED), spectroscopie de photoélectrons excités par rayons X (XPS) et microscopie à effet tunnel (STM) supportés par ces calculs ab initio ont révélé qu’à partir de 320°C, le composé Al9Ir2 se formait en surface mais également dans une partie du volume du substratA complex metallic alloy (CMA) is an intermetallic compound whose unit cell contains a large number of atoms oftenly forming highly-symmetric clusters. From the complexity of these compounds can arise physical and chemical properties interesting for various fields of application. The aluminium-iridium binary system exhibits numerous intermetallic compounds of which half of them are actually CMAs. Despite this system being extensively studied in the literature, some uncertainies remained unsolved, leading us to reinvestigate the Al-Ir phase diagram. In addition, the "push-pull" systems Al-Au-Ir and Al-Ag-Ir, favorable for the formation of CMA according to the literature, have been explored. Thus, near a hundred of samples have been prepared by arc-melting before being analyzed with different characterizations techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and differential thermal analysis (DTA). From this study, 4 new intermetallic compounds could be identified: Al2.4Ir, Al72Au2.5Ir29.5, Al3AuIr and Al11SiIr6, the latter being the result of a fortuitous manipulation. The crystallographic structure of each of these compounds has been solved, revealing Al2.4Ir and Al72Au2.5Ir29.5 to be two CMAs with around one hundred of atoms in their unit cell. Calculations based on the density functional theory (DFT) brought further details about the stability of the two other Al3AuIr and Al11SiIr6 compounds. In the Al-Ir binary system, a structural variant of two well-known CMAs has been also unveiled. The crystallographic structures of the Al2.75Ir and Al28Ir9 variant have been approached, revealing 240 and 444 atoms in their respective unit cell. The CMAs oftently exhibit interesting surface properties. In order to study the Al-Ir compound surfaces, iridium adsorption on Al(100) surface followed by annealing has been investigated. The characterizations by lowenergy electrons diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning tunneling miscoscopy (STM) supported by ab initio calculations revealed that, from 320 C, the Al9Ir2 compound is formed at the surface but also in the substrate bulk
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Antoun, Marc. "Vers une meilleure compatibilité ciment/mâchefer (MIDND) dans la formulation de matériaux cimentaires intégrant un ciment sulfo-alumineux". Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2019. http://www.theses.fr/2019MTLD0002.
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Dans un contexte accru d’économie circulaire et de valorisation des matières premières recyclées, les mâchefers d’incinération de déchets non dangereux (MIDND) constituent des déchets granulaires minéraux identifiés comme ressources renouvelables potentiellement valorisables dans la filière construction, notamment dans le domaine des matériaux cimentaires (type mortier/béton). Compte tenu de l'origine et de la nature des granulats de mâchefers, dans une finalité de concourir à une meilleure compatibilité mâchefer/ciment, il apparait essentiel en premier lieu de considérer des fractions minérales de mâchefers au mieux épurées par l’optimisation de l’enlèvement des métaux ferreux, non-ferreux et indésirables. En second temps, tenant compte des spécificités physico-chimiques résultantes des mâchefers, le choix de la base cimentaire constitue le second facteur prépondérant en sus de la nécessité de meilleure qualité de la fraction minérale de mâchefer. Le présent travail doctoral traite spécifiquement de l’apport de l’utilisation d’un ciment sulfo-alumineux dans le contexte de valorisation des mâchefers en matrice cimentaire. Des sables de mâchefers améliorés de fraction 0/2 mm ont été élaborés et utilisés pour l’étude. Dans une première partie, les résultats de formulation de mortiers cimentaires (ciment Portland, noté OPC / ciment sulfo-alumineux, noté CSA) à base de mâchefers en substitution volumique partielle du sable naturel (25, 50 et 75 %) et totale (100 %), mettent en évidence l’apport bénéfique du ciment CSA sur les résistances en compression par comparaison aux mortiers OPC. Une analyse expérimentale du réseau poreux des mortiers à 90 jours révèle que la frange de porosité supérieure à 50 nm est nettement plus faible pour les mortiers CSA. La thèse met en évidence un résultat majeur et pionnier : en interaction mâchefer, le niveau de basicité du milieu réactionnel joue un rôle prépondérant sur le potentiel de dégagement gazeux (hydrogène) après la mise en œuvre et avant la prise. Ce gaz impacte le niveau de porosité de la frange la plus grossière des mortiers durcis. La seconde partie concerne l’étude physique et microstructurale des mortiers soumis à l’attaque à l’eau pure ou à attaque sulfatique pour des substitutions volumiques de 50 et 100 %, avec les témoins pour référentiels. Les observations MEB sur les différentes matrices mettent en évidence une nette moindre sensibilité des mortiers mâchefer/CSA que des mortiers mâchefer/OPC, traduit par des porosités, fissurations et épaisseurs dégradées moindresIn a world where circular economy and the valorization of raw materials is taking a greater importance, municipal solid waste incineration (MSWI) bottom ash is identified as potentially renewable resource in the construction field and more specifically in cementitious materials like mortar and concrete. Given the origin of the bottom ash and in order to have a better cement/MSWI bottom ash compatibility, the fraction used was as refined as possible by removing ferrous, non-ferrous and unwanted materials. The choice of the cement used is a critical factor as well because it affects the quality of the end product since MSWI bottom ash has particular physicochemical properties. The work in this PhD studies the advantages of using a sulfo-aluminate cement to valorize an improved 0/2 mm fraction of bottom ash that has been developed to be used in cementitious matrices. The first part presents the results of the mortar sample mixes containing bottom ash in a substitution by volume of the standard sand. To better highlight the effect of using a sulfo-aluminate (CSA), CSA mortars containing bottom ash were compared to a Portland cement (OPC) mortars, with substitution rates of 25 %, 50 %, 75 % and 100 % were used. A study of the porosity was then conducted at 90 days ; it shows that the pores larger to 50 nm are remarkably less present for CSA mortars. This thesis brings forward a major and innovative result : the level of alkalinity of the mortar plays an important role in the release of hydrogen gas after mixing and before setting. The presence of these gases creates large porosity in the hardened mortar samples. The second part studies the physical and microstructural aspects of the mortars after being immersed in aggressive environments : pure water and sulfate solution. The substitution rates used in this experiment were 50 % and 100 % by volume as well as the reference mortars with no bottom ash. These samples were then studied in the SEM which showed that CSA/bottom ash mortars were clearly less affected than the OPC/bottom ash mortars. This was highlighted by the porosity, the cracking and the depth of degraded zone
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Chen, Jianqiang. "Déchirure ductile des tôles en alliages d'aluminium-lithium 2198 pour application aéronautique". Phd thesis, École Nationale Supérieure des Mines de Paris, 2011. http://pastel.archives-ouvertes.fr/pastel-00657028.
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L'objectif de cette thèse est de progresser dans la compréhension de l'influence de la microstructure sur l'anisotropie plastique et la ténacité de deux nuances d'alliage Al-Cu-Li 2198 sous forme de tôle. L'épaisseur de tôles est 2 mm et 6 mm. Deux traitements thermiques (T351 et T851) ont été étudiés pour chaque nuance. Différentes techniques de caractérisation multi-échelles telles que la microscopie optique, la microscopie électronique en transmission ou encore la tomographie à rayons X ont été utilisées pour identifier les microstructures des matériaux et les micro-mécanismes d'endommagement. L'anisotropie plastique et l'effet d'épaisseur sur la plasticité ont été étudiés via des essais de traction sur les éprouvettes lisses et entaillées selon différentes directions. Les résultats montrent que le comportement plastique est anisotrope dans le plan de tôle. Le comportement en déchirure ductile a été examiné en utilisant des éprouvettes de petite taille de type Kahn ainsi que des plaques larges de type M(T). L'anisotropie de ténacité a été étudiée sur les éprouvettes chargées selon différentes configurations. La fractographie par microscope électronique à balayage (MEB) et la tomographie synchrotron aux rayons X ont clarifié le rôle des structures granulaires et des traitements thermiques sur les mécanismes de la rupture inter-granulaire et trans-granulaire. La croissance de cavités reste limitée dans la zone de propagation de fissure. En fin, la simulation de la déchirure ductile par élément finis est basée sur l'approche locale de la rupture en utilisant un modèle de zone cohésive (CZM). Les paramètres cohésifs ont été ajustés sur les éprouvettes Kahn. Les paramètres identifiés ont été employés pour prédire la déchirure ductile des essais M(T). Les résultats montrent que la simulation des essais M(T) est plus sensible aux valeurs des paramètres ajustés que la simulation des essais Kahn. L'effet d'épaisseur a été évalué à l'aide de la technique de relâchement des nœuds en analysant la variation de la contrainte et de la déformation dans la direction de l'épaisseur.
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Pimenidou, Panagiota, N. Shanmugapriya y N. Shah. "Performance and emissions study of diesel and waste biodiesel blends with nanosized CZA2 of high oxygen storage capacity". 2018. http://hdl.handle.net/10454/16857.
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yesIn this work, the effect of the nanosized CZA2 (cerium-zirconium-aluminium) on the performance and emissions in a two- cylinder indirect injection (IDI) diesel engine, was studied. CZA2 was dispersed in diesel (D100) and waste cooking oil and tallow origin biodiesel-diesel blends (B10, B20, B30) and tested at different engine loads and constant speed. The nanocatalyst (CZA2) increased the brake specific fuel consumption (BSFC) and decreased the brake thermal efficiency (BTE, %) of all tested fuels, at all loads, except B20 at the lowest load. CZA2 reduced nitrogen oxides (NOx) from D100 at low and high engine loads, as well as carbon monoxide (CO) and unburned hydrocarbons (HC) at medium and high tested loads. The dispersion of CZA2 promoted the combustion of the biodiesel blends by almost eliminating HC while reducing NOx and CO emissions at various loads. Thermogravimetric analysis (TGA) coupled with Attenuated Total Reflectance- Fourier Transform Infrared (ATR-FTIR) spectroscopy revealed that the addition of CZA2 in diesel and biodiesel under pyrolysis and oxidation conditions resulted in the presence of saturated species like ketones and final oxidation products such as CO2, supporting their improved combustion and emissions’ reduction in the engine tests.
The full text will be available at the end of the publisher's embargo, 29th Nov 2019
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"Tio₂nanocatalysts: synthesis, layer-by-layer immobilisation on glass slides and their support on carbon-covered alumina (cca) for application in drinking water treatment". Thesis, 2012. http://hdl.handle.net/10210/5977.
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D.Phil.Clean water (i.e. water that is free of toxic chemicals and pathogens) is essential to human health and in South Africa the demand is fast exceeding the supply. The prevalence of toxic contaminants in water remains a huge challenge for water supplying companies and municipalities. However, the presently used water treatment technologies either fail to remove these contaminants to acceptable levels or they transform them into more toxic substances (e.g., DBPs). Nanocatalysts, especially TiO2 (titania) have a proven potential to treat ‘difficult-to-remove’ contaminants and hence are expected to play an important role in solving many serious environmental and pollution challenges. In this study TiO2 nanocatalysts were used for the degradation of Rhodamine B dye both under UV and visible light irradiation. Two phases of titania, i.e. anatase and rutile phases, were compared for the degradation of Rhodamine B under UV light irradiation. The anatase titania was found to be more photocatalytically active for the degradation of Rhodamine B than the rutile phase. It completely degraded 100 mg ℓ–1 (100 mℓ) of Rhodamine B within 270 min and was two times more photocatalytically active than the rutile phase (Kapp of 0.017 min–1 compared to 0.0089 min–1). To extend the band edge of the titania nanocatalysts towards visible-light, TiO2 was doped with metal ions (Ag, Co, Ni and Pd). These metal-ion-doped titania nanocatalysts were photocatalytically active under visible-light illumination. The Pd-doped titania had the highest photodegradation efficiencies, followed by Ag-doped and Co-doped, while Ni-doped had the lowest. The optimum metal-ion loading percentage was found to be at 0.4%, with the exception of Co-doped titania as it had the highest efficiencies at 1% loadings. The free and metal-ion-doped titania nanocatalysts were embedded on carbon-covered alumina (CCA) supports. The CCA-supported TiO2 nanocatalysts were more photocatalytically active under visible light illumination than they were under UV-light irradiation. The CCA-supported metal-ion-doped titania nanocatalysts were more photocatalytically active under visible light than their unsupported counterparts. The CCA-supported Pd-TiO2 nanocatalysts were the most active while CCA-supported Ni-TiO2 catalysts were the least active. The improved photocatalytic activities observed were as a result of increased surface areas of the CCA-supported nanocatalysts. Also, supporting the nanocatalysts did not destroy the anatase phase of the titania while doping with metal ions and supporting on CCAs resulted in decreased band gap energies, hence the visible-light photocatalytic activities. Finally, the metal-ion-doped titania nanocatalysts were supported on glass slides using the layer-by-layer thin film self-assembly technique. This was to overcome the aggregation and post treatment problems associated with the use of TiO2 in suspension form. PAH and PSS were the polyelectrolytes used. These metal-ion-doped titania thin films were highly porous and strongly adhered by the polyelectrolytes onto the glass slides. The thin films were photocatalytically active for the degradation of Rhodamine B under visible light irradiation. The photocatalytic degradation efficiencies observed were similar for all four metal-ions (i.e. Ag, Co, Ni and Pd) with average degradation of 30%, 50%, 70% and 90% for 5 catalysts (5 glass slides) of 1, 3, 5 and 10 bi-layers, respectively, after 330 min. Although, these were less active than the suspended titania nanocatalysts, this study proved as a stepping stone towards large scale use of titania nanocatalysts using solar energy as the irradiation source. Also, catalyst reusability studies were performed and the PAH/PSS m-TiO2 thin films were found to be highly stable over the five cycles it was tested for.
Libros sobre el tema "Aluminum (CZA)"
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Voinescu, Alexandra, Nadia Wasi Iqbal y Kevin J. Martin. Management of chronic kidney disease-mineral and bone disorder. Editado por David J. Goldsmith. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0118_update_001.
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In all patients with chronic kidney disease (CKD) stages 3–5, regular monitoring of serum markers of CKD-mineral and bone disorder, including calcium (Ca), phosphorus (P), parathyroid hormone (PTH), 25-hydroxyvitamin D, and alkaline phosphatase, is recommended. Target ranges for these markers are endorsed by guidelines. The principles of therapy for secondary hyperparathyroidism include control of hyperphosphataemia, correction of hypocalcaemia, use of vitamin D sterols, use of calcimimetics, and parathyroidectomy. of hyperphosphataemia is crucial and may be achieved by means of dietary P restriction, use of P binders, and P removal by dialysis. Dietary P restriction requires caution, as it may be associated with protein malnutrition. Aluminium salts are effective P binders, but they are not recommended for long-term use, as Aluminium toxicity (though from contaminated dialysis water rather than oral intake) may cause cognitive impairment, osteomalacia, refractory microcytic anaemia, and myopathy. Ca-based P binders are also quite effective, but should be avoided in patients with hypercalcaemia, vascular calcifications, or persistently low PTH levels. Non-aluminium, non-Ca binders, like sevelamer and lanthanum carbonate, may be more adequate for such patients; however, they are expensive and may have several side effects. Furthermore, comparative trials have failed so far to provide conclusive evidence on the superiority of these newer P binders over Ca-based binders in terms of preventing vascular calcifications, bone abnormalities, and mortality. P removal is about 1800–2700 mg per week with conventional thrice-weekly haemodialysis, but may be increased by using haemodiafiltration or intensified regimens, such as short daily, extended daily or three times weekly nocturnal haemodialysis. Several vitamin D derivatives are currently used for the treatment of secondary hyperparathyroidism. In comparison with the natural form calcitriol, the vitamin D analogue paricalcitol seems to be more fast-acting and less prone to induce hypercalcaemia and hyperphosphataemia, but whether these advantages translate into better clinical outcomes is unknown. Calcimimetics such as cinacalcet can significantly reduce PTH, Ca, and P levels, but they have failed to definitively prove any benefits in terms of mortality and cardiovascular events in dialysis patients. Parathyroidectomy is often indicated in CKD patients with severe persistent hyperparathyroidism, refractory to aggressive medical treatment with vitamin D analogues and/or calcimimetics. This procedure usually leads to rapid improvements in biochemical markers (i.e. significant lowering of serum Ca, P, and PTH) and clinical manifestations (such as pruritus and bone pain); however, the long-term benefits are still unclear.
Capítulos de libros sobre el tema "Aluminum (CZA)"
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Wang, Ru. "The Role of Polymer in Calcium Sulfoaluminate Cement-Based Materials". En Springer Proceedings in Materials, 171–80. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72955-3_16.
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AbstractIn order to realize sustainable development, new types of cements were paid more attention. Calcium sulfoaluminate (CSA) cement is a kind of eco-friendly cement that has the characteristics of low carbon emission, low energy consumption, fast setting and hardening, and so on. But the main hydration product ettringite (AFt) is quite sensitive to curing conditions that makes CSA cement-based materials sensitive to temperature and ageing. Polymer plays a key role in improving the properties of CSA cement mortar. Our researches showed that styrene-butadiene copolymer (SB) could result in a big reduction of zeta potential and conductivity of the CSA cement paste, retard the very initial hydration of CSA cement but not after 3 h, and lead to the generation of more AFt and aluminium hydroxide (AH3). With SB addition increasing, the yield stress, viscosity, thixotropy, fluidity and thus workability of CSA cement mortar were significantly improved. The mechanical strength of CSA cement mortar showed a reduction after a certain age, but when SB was added there was no reduction anymore under various curing conditions. SEM observation of the morphology accounts well for the changes in mechanical properties. The shrinkage, water capillary adsorption, and durability such as resistance to freezing and thawing cycle, carbonization and sulfate attack were also investigated. This paper reviewed the role of polymer in CSA cement-based materials taking SB as an example based on recent research work of our group.
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Franco, Thiago Teixeira y Roberto Seno Junior. "Votorantim Metals - CBA Alumina Refinery Precipitation Modeling". En Light Metals 2014, 31–37. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118888438.ch5.
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Franco, Thiago Teixeira y Roberto Seno Junior. "Votorantim Metais — CBA Alumina Refinery Precipitation Modeling". En Light Metals 2014, 33–37. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-48144-9_5.
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Sun, Chen, Minghua Dai, Liang Ying, Kai Du, Zhigang Chen y Ping Hu. "Experimental and Numerical Simulation on Formability and Failure Behavior of Thermoplastic Carbon Fiber/AL Composite Laminates". En Lecture Notes in Mechanical Engineering, 383–93. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-58006-2_30.
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AbstractCarbon fiber reinforced thermoplastic/aluminum alloy (CFRTP/AL) composite laminates have the advantages of low density, high specific strength, and good fatigue resistance, which is a new type of engineering composite material to realize lightweight vehicle body. Heterogeneous interface delamination failure occurs in the forming process of the fiber metal laminates (FMLs). It is necessary to establish an effective finite element simulation strategy to accurately predict the delamination failure behavior of FMLs. In this work, thermoplastic PA6 continuous carbon fiber/AL FMLs were taken as the research object, and the double cantilever beam (DCB) and the end-notched flexure (ENF) experiments were carried out to determine the basic mechanical parameters between the interlayer interfaces of CFRTP/AL. Furthermore, a numerical simulation model based on ABAQUS software was developed to describe the progressive damage failure behavior of the CRFTP/AL in the forming process by using the equivalent modeling strategy of discontinuous micro-shear, which realized the effective prediction of ply directional damage failure of FMLs on the basis of the S-beam model. The results show that the established damage constitutive model and numerical method coupled with cohesive zone model (CZM) can effectively predict the ply directional damage failure behavior of CFRTP/AL composites during the large deformation forming.
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Haus, Steffen, Allan Borges, Natalia Almeida y Anderson Duck. "Results of Metso Outotec Calciner Optimizer Operation at CBA Alumina Calcination Plants". En Light Metals 2022, 22–30. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92529-1_3.
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Begum, Fathimunnisa, Sasidhar Gurugubelli y N. Ravi Kumar. "Observational Exposition of Metal Matrix Composite Aluminum 6069 (Al) Fraction Variance Strengthened with Molybdenum (Mo) and Coconut Shell Ash (CSA)". En Recent Advances in Manufacturing, Automation, Design and Energy Technologies, 105–13. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-4222-7_12.
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Mahlambi, Mphilisi M., Ajay K. Mishra, Shivani B. Mishra, Rui W. Krause, Bhekie B. Mamba y Ashok M. Raichur. "Synthesis and characterization of carbon-covered alumina (CCA) supported TiO2 nanocatalysts with enhanced visible light photodegradation of Rhodamine B". En Nanotechnology for Sustainable Development, 89–99. Cham: Springer International Publishing, 2012. http://dx.doi.org/10.1007/978-3-319-05041-6_7.
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Rosas, Marcelo M. F. O., Raul D. S. G. Campilho, Isidro J. Sánchez-Arce, Raul D. F. Moreira y Ricardo J. B. Rocha. "Evaluation of the Optimal Tubular Adhesive Joint Geometry for Structural Applications". En Versatile Approaches to Engineering and Applied Sciences: Materials and Methods. Özgür Yayınları, 2023. http://dx.doi.org/10.58830/ozgur.pub50.c73.
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Adhesive bonding technology have been widespread in several industrial sectors owing to relevant benefits in comparison to conventional mechanical fastening methods like bolting or riveting. Bonded joints, in their varied formats, have been utilized in many industries as is the case of aeronautical, automotive, naval, wind energy, among others. Tubular adhesive joints (TAJ), although being rarely studied, have found their space and applicability in the construction, motor sports or pipeline industries. In this work it was performed a numerically study, involving cohesive zone modelling (CZM), aiming to assess the influence of geometrical changes on the performance of aluminium TAJ connected with Araldite® 2015 adhesive. The numerical axisymmetric CZM models used in this work were previous validated with experimental results. The geometrical variations for TAJ considered in this work were an outer chamfer, an inner chamfer (both in the adherends), and adding an adhesive fillet at the overlap ends. The geometrical variations analysed in this work have shown significant stress reductions although they are not reflected in an elevated increase in terms of the joint maximum strength, this is mainly due to plasticization of the aluminium adherends.
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"Effects of Doping and Post-Treatments on PANI Films". En Advances in Chemical and Materials Engineering, 138–56. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9896-1.ch005.
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It is well known that the sample preparation, experimental measurement, and technique have played a vital role in empirical research work. In this chapter, the detailed discussions on the doping and various post-treatments on the PANI thin films have been made. The in-depth studies on gold, silver, aluminum, lithium, HCl, and camphor sulfonic acid (CSA) doped PANI nanocomposites and thin films have been undertaken in this chapter, followed by discussing the effect of post-annealing treatment and ion reaction medium. The impact of different doping and post-treatment on the properties of PANI films viz. microstructural, optical-electrical, thermal, etc., have been analyzed herein. The structural and optoelectrical properties of PANI films and its nanocomposites have also been discussed in which metal-nanoparticles inserted PANI films achieve particular consideration due to its relatively thought-provoking non-linear optical properties.
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M. Lankapati, Henilkumar, Kalpana C. Maheria y Ajay K. Dalai. "Transformation of Waste Coal Fly Ash into Zeolites for Environmental Applications". En Coal Energy in the 21st Century [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.108252.
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The generation of a large quantity of waste coal fly ash (CFA) via coal combustion process during power generation is of major concern as disposal of such huge quantity of fly ash causes serious threats to the environment. There is an exigent need to find out the proper solution for its disposal/utilization to reduce its harmful effects. The composition of waste coal fly ash mostly consists of silica and alumina. Hence, the researchers are tempted to utilize waste coal fly ash as a starting ingredient to make value-added materials like zeolites. It is anticipated that such research efforts will act as a valuable aid to reduce the disposal cost of fly ash and ultimately reduce harmful effects of fly ash to the environment. In this review, various synthesis methods to synthesize different types of zeolites from CFA, such as Zeolite-A, Zeolite-X and Zeolite-P, have been summarized and their potential for various applications such as sorption and catalysis has been explored.
Actas de conferencias sobre el tema "Aluminum (CZA)"
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Duck, Anderson R. K., André L. Arantes, Wagner L. S. Guerra, Tiago B. Carriel y Thiago T. Franco. "Aumento de yield na produção de alumina da CBA". En ANAIS DO 9° CONGRESSO INTERNACIONAL DO ALUMíNIO. Galoa, 2024. http://dx.doi.org/10.17648/congressoaluminio-2024-183791.
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Pandit y Buchheit. "Control schemes for a cyclically operating aluminum extruder plant". En Proceedings of IEEE International Conference on Control and Applications CCA-94. IEEE, 1994. http://dx.doi.org/10.1109/cca.1994.381427.
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Ghisleni, Geisiele y Janaíde Cavalcante Rocha. "AVALIAÇÃO EXPERIMENTAL DE SUBPRODUTOS COMO PRECURSORES NO DESENVOLVIMENTO DE SISTEMAS ÁLCALI ATIVADOS". En XVIII ENCONTRO NACIONAL DE TECNOLOGIA DO AMBIENTE CONSTRUÍDO. UFRGS, 2020. http://dx.doi.org/10.46421/entac.v18i.991.
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O uso de cimentos alternativos intensifica-se na construção civil, uma vez que, a produção de cimento Portland emite quantidades consideráveis de CO2, devido a queime do clínquer. Os sistemas álcali ativados são uma proposta, onde, o aglomerante convencional é substituído por precursores, que na sua maioria são resíduos industriais ou subprodutos, que juntos tencionam a minimização dos impactos ambientais. O presente estudo objetivou testar os resíduos cinza pesada (CZP), cinza de casca de arroz (CCA) e lama vermelha (LV), por meio de avaliações experimentais a capacidade de estes serem precursores no desenvolvimento de sistemas álcali ativados. A pesquisa delineou-se em caracterizar e amostrar os precursores com beneficiamento de secagem e/ou a calcinação, buscando o melhoramento da microestrutura do material. Aplicou-se nestes, o teste de pH em solução por 24horas, a difração de raio-X (DRX) e a energia de dispersão de raios-X (EDX). Os resultados demonstraram que todos os precursores obtêm pH alcalino, fator que contribui na interação da reatividade nas reações químicas, entretanto, a CCA corroborou resultados interessantes, com maior superfície especifica o que contribui na reatividade e uma composição de 92,74% de sílica, entretanto, ausência de alumina. Conclui-se que o CCA destaca-se como um precursor para a composição binária de sistemas álcali ativados.
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Duck, Anderson R. K., Raquel M. Montagnoli, Ricardo C. Padilha y Daniel Bigongiari. "Redução de emissões de CO2 na refinaria de alumina da CBA". En ANAIS DO 9° CONGRESSO INTERNACIONAL DO ALUMíNIO. Galoa, 2024. http://dx.doi.org/10.17648/congressoaluminio-2024-183797.
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Leblanc, Jean-M. y Jean-Pierre Rozelot. "Large active mirror in aluminium". En San Diego, '91, San Diego, CA, editado por Gary W. Wilkerson. SPIE, 1991. http://dx.doi.org/10.1117/12.48308.
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Goto, Kenta, Takehiro Higuchi, Ohmi Fuchiwaki y Wataru Nakao. "Performance of Capsule-Type Micro Actuator Using Hydrogen Storage Alloys". En ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3084.
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Capsule-type micro actuator driven by the volume change of hydrogen storage alloys (HSA-CMA) was proposed to be applied as an actuator mounted on the joints of the super multilink manipulator to capture space debris. This actuator consists of a hollow sphere frame made of aluminum, a membrane of hydrogen storage alloys and a valve, and is compact and lightweight. The aim of this study was to evaluate the availability of HSA-CMA. Finite element analyses were performed to investigate the actuator displacement and the generating force as the static performance, and the obtained static performances were compared with that of other smart actuators. The analysis on the actuator displacement led to the design map of HSA-CMA. The comparison result suggests that HSA-CMA has the actuator displacement and the generating force as well or better than other smart actuators and that it is suitable for use in space.
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Kraft, Edward, Kevin Laux, Albert To y Mark L. Kimber. "Thermal-Hydraulic Performance of Aluminum Foam Heat Exchangers with Varying Cellular Lattice Structures". En Second Thermal and Fluids Engineering Conference. Connecticut: Begellhouse, 2017. http://dx.doi.org/10.1615/tfec2017.cfa.018116.
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Tomie, Toshihisa, Isao Okuda, Isao Matsushima, Yoshiro Owadano, R. Staffin, M. Yano, H. Kondo y James N. Broughton. "High-density aluminum plasma produced by a picosecond KrF laser pulse". En San Diego, '91, San Diego, CA, editado por Szymon Suckewer. SPIE, 1992. http://dx.doi.org/10.1117/12.134823.
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Ancelet, O., S. Marie, L. Allais, P. Wident, L. Brianc¸on, D. Guilbaud, D. Bonne y A. F. Bonnot. "Presentation of a Toughness Benchmark on a Low Ductility Material: 6061-T6 Aluminium". En ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25668.
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The aluminum alloy 6061-T6 is a material used for some part of experimental reactor for its interesting physical and mechanical proprieties. To respect the European rules on pressure equipments, a material must present some minimal characteristics for toughness and ductility. In particular, a preventive analysis against abrupt break can be performed in order to ensure the integrity of the structure. In this frame, some characterizations of the toughness were undertaken. Some tests present singular propagation at the beginning of the crack propagation. These singular crack propagation brings some difficulties in the interpretation of the testing and in the J0,2BL/JIC determination. It is the reason why a benchmark on the determination of this value for such material was organized between three different laboratories: the LISN of the French atomic commission (CEA), the LC2M of the CEA and the CESMAN of the DCNS industry. All participants receive a piece of the same material and realize some toughness testing according to its own usage. The benchmark allows comparing the different experimental methodology (machining specimen, pre-crack, testing conditions, equipments …) and the interpretation methodology (ASTM 1820 and ISO 12135 application). This leads to propose a list of recommendations on the realization of the toughness testing and more specifically some necessary adaptation of the ASTM 1820 and ISO 12135 standard for such material.
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Hubert, H., F. Blein, A. Freslon, M. Jeandin, C. Le Paven y P. Houdy. "Role of Atmosphere During Plasma Processing for Application to Plasma Spraying of Aluminum Onto Polyethyleneterephtalate (PET)". En ITSC 1998, editado por Christian Coddet. ASM International, 1998. http://dx.doi.org/10.31399/asm.cp.itsc1998p1469.
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Abstract Polymeric substrates have to be severely cooled during the plasma spraying process to limit detrimental effect due to the high heating flow from the plasma jet. The « Atmosphere and Temperature Controlled process » (ATC, patented by CEA) was used to maintain the substrates near room temperature. However, the PET substrates might undergo some superficial modifications which could result from the plasma jet heating and particle heating at the impact. This paper deals with a study of chemical modifications in PET as a function of surrounding atmospheres during plasma processing. Aluminum coating adhesion was determined using tensile tests.
Informes sobre el tema "Aluminum (CZA)"
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Kuo, Chu K. y James J. Brophy. Conductivity Fluctuations in Mixed Na/Ca Beta Alumina. Fort Belvoir, VA: Defense Technical Information Center, febrero de 1989. http://dx.doi.org/10.21236/ada205416.
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Czahor, Charles. Aluminum/calcium deformation metal-metal composites after conversion to Al2Ca intermetallic reinforcement. Office of Scientific and Technical Information (OSTI), diciembre de 2016. http://dx.doi.org/10.2172/1505194.
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Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen y Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils: Speciation, Transport, and Accumulation. United States Department of Agriculture, junio de 2011. http://dx.doi.org/10.32747/2011.7697103.bard.
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Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.