Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure

first_pagesettingsOrder Article Reprints Open AccessArticle Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy * Author to whom correspondence should be addressed. Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602 Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023 Downloadkeyboard_arrow_down Browse Figures Review Reports Versions Notes Abstract SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings

New family host and records of Acanthocrios furnarii (Cordero & Vogelsang, 1928) (Hemiptera: Cimicidae) from Argentina, and implications in the transmission mechanism of cimicid bugs among birds’ nests

Acanthocrios furnarii (Cordero & Vogelsang, 1928) [Hemiptera: Cimicidae: Haematosiphoninae] is an ectoparasite on avian hosts from Argentina and Uruguay. It has been mostly found in mud nests of Furnarius rufus (Gmelin, 1788) [Aves: Furnariidae], but its true hosts are some of the inquiline birds that use F. rufus nests. These inquiline hosts belong to the families Emberizidae, Hirundinidae, Icteridae, Passeridae, and Troglodytidae. Outside F. rufus mud nests, A. furnarii has been found in nests of other Furnariidae, Hirundinidae, and Passeridae. The present work adds the first nonpasserine host (Falconidae) of A. furnarii, together with new records in La Pampa, Argentina. The transmission mechanism of A. furnarii, together with all other cimicid bugs from Argentina and adjacent countries, is increased considering this new host; and we also take into account the birds that nidificate in nest boxes, the cavity-nesting birds in trees and earth, and the inquiline birds in stick nests of Furnariidae and Psittacidae.Fil: Di Iorio, Osvaldo Rubén. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Turienzo, Paola Noemí. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bragagnolo, Laura Araceli. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santillán, Miguel Ángel. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; ArgentinaFil: Grande, Juan Manuel. Universidad Nacional de La Pampa. Facultad de Ciencia Exactas y Naturales. Departamento de Recursos Naturales. Centro para el Estudio y Conservación de Aves Rapaces; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

Developmet effects on working memory and category learning in children

Se han reportado diferencias relacionadas con la edad en el desempeño de diversas tareas dependientes del lóbulo frontal, incluyendo tareas de memoria de trabajo (Luciana and Nelson, 1998; Luna et al. 2001; Bunge et al., 2002). Se han encontrado también efectos de edad y género sobre la memoria de trabajo en niños (Vuontela et. al, 2003). Además, el aprendizaje de categorías ha sido asociado con la actividad del lóbulo frontal (Dickins, 2000; Schlund 2007). El presente trabajo investigó los efectos de la edad y el género sobre la memoria de trabajo y el aprendizaje de categorías en niños de 8 a 13 años. Se encontraron efectos de edad y género sobre la memoria de trabajo, y en la tarea de aprendizaje de categorías sólo se observaron efectos de la edad. Los resultados sugieren que el desempeño de memoria de trabajo podría estar asociado con la velocidad de procesamiento en el aprendizaje de categorías.Age-related differences have been reported in the performance of several frontal lobe-dependent tasks, including working memory (Luciana and Nelson, 1998; Luna et al. 2001; Bunge et al., 2002). Effects of age and gender on working memory have been found in children (Vuontela et. al, 2003). On the other hand, category learning has also been associated with frontal lobe activity (Dickins, 2000; Schlund 2007). The present study addressed the effects of age and gender on working memory and category learning, in 8-13 year old children. Age and gender effects were found on the working memory task, and age effects only were observed on category learning. The results suggest that working memory performance might be associated with processing speed in the category learning task.Fil: Sánchez, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tabullo, Angel Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marro, Claudia Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sánchez, María Laura.Fil: Iorio, Alberto Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segura, Enrique Teodoro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Normas Primárias e Secundárias do Setor de Telecomunicações - 2011

Statutes, regulations, administrative and judicial decisions applied to the telecommunications sector in Brasil in 2011.Leyes, reglamentos, actos administrativos y decisiones judiciales relativas al sector de telecomunicaciones en Brasil en 2011.Leis, regulamentos, atos administrativos e decisões judiciais relativas ao setor de telecomunicações no Brasil em 2011

Methods for preparation and administration of lutetium-177 oxodotreotide 3.7 GBq: proceedings from an Italian advisory board

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Measured Copper Toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae) and Predicted by Biotic Ligand Model in Pilcomayo River Water: A Step for a Cross-Fish-Species Extrapolation

In order to determine copper toxicity (LC50) to a local species (Cnesterodon decemmaculatus) in the South American Pilcomayo River water and evaluate a cross-fish-species extrapolation of Biotic Ligand Model, a 96 h acute copper toxicity test was performed. The dissolved copper concentrations tested were 0.05, 0.19, 0.39, 0.61, 0.73, 1.01, and 1.42 mg Cu L−1. The 96 h Cu LC50 calculated was 0.655 mg L−1 (0.823 − 0.488). 96-h Cu LC50 predicted by BLM for Pimephales promelas was 0.722 mg L−1. Analysis of the inter-seasonal variation of the main water quality parameters indicates that a higher protective effect of calcium, magnesium, sodium, sulphate, and chloride is expected during the dry season. The very high load of total suspended solids in this river might be a key factor in determining copper distribution between solid and solution phases. A cross-fish-species extrapolation of copper BLM is valid within the water quality parameters and experimental conditions of this toxicity test

Group follow up proposal for elderly with hearing aids

Implementing rehabilitation programs to hearing impaired adults is of great importance, mainly in the elderly population, and it is necessary to add them to the routine of outpatient care programs. AIM: to present a group care program for elderly patients who are fitted with hearing aids. MATERIAL AND METHOD: to carry out a pilot study of clinical and experimental type, with the participation of 40 elderly users of hearing aids donated by the government, distributed within six groups, with maximum of eight participants jointly with their respective companions. Program consisted of three meetings every fifteen days, where information and education on the proper use hearing aids was transmitted. RESULTS: Most of the patients participated actively in the meetings spontaneously giving their opinion or answering questions when so requested. All elderly had been informed as to the importance of accepting their auditory deficiency and on the need to be motivated towards using hearing aids. Moreover, listening to depositions of other elderly users seemed to facilitate understanding of their own difficulties and stimulated them in the process of getting used to the sound amplification. CONCLUSION: Groups structure facilitated interaction among aged ones, helping them to clarify communication doubts and strategies and, consequently, it promoted their adaptation.A implantação de programas de reabilitação para o deficiente auditivo adulto é de grande importância, principalmente na população geriátrica, sendo necessário incorporá-los à rotina dos serviços ambulatoriais. OBJETIVO: Apresentar um programa de atendimento em grupo voltado para idosos protetizados. MATERIAL E MÉTODO: Realizar um estudo piloto do tipo clínico e experimental, com a participação de 40 idosos usuários de próteses auditivas, doadas em um Serviço Público, distribuídos em seis grupos, com no máximo oito idosos mais seus respectivos acompanhantes. O programa constou de três encontros quinzenais, onde foram transmitidas informações e orientações necessárias para adequada adaptação dos idosos ao uso das próteses auditivas. RESULTADOS: A maioria dos idosos participou dos encontros ativamente, expondo suas opiniões espontaneamente ou respondendo as questões quando solicitado. Todos os idosos foram orientados quanto à importância da aceitação da deficiência auditiva e sobre a necessidade de motivação para o uso das próteses auditivas. Além disso, ouvir depoimentos dos outros idosos pareceu facilitar a compreensão das suas próprias dificuldades e os estimulou no processo de adaptação à amplificação. CONCLUSÃO: a formação de grupos facilitou a interação entre idosos, permitiu o esclarecimento das dúvidas e estratégias de comunicação e, conseqüentemente, favoreceu o processo de adaptação.UNIFESP-EPMUNIFESP-EPM Núcleo Integrado de Atendimento, Pesquisa e Ensino em AudiçãoNIAPEAHospital São Paulo Centro Auditivo Teuto Brasileiro Centro de Deficiente AuditivoUNIFESP-EPM Departamento de FonoaudiologiaUNIFESP, EPM, Núcleo Integrado de Atendimento, Pesquisa e Ensino em AudiçãoHospital São Paulo Centro Auditivo Teuto Brasileiro Centro de Deficiente AuditivoUNIFESP, EPM Depto. de FonoaudiologiaSciEL