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Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents the analysis of the Dicionário da Língua de Sinais do Brasil: a Libras em suas mãos by Capovilla et al. (2019). It is the most relevant and widespread Libras dictionary in the country, being the most recent version of the dictionaries produced by Capovilla's team. This study is part of the doctoral research in Letters at the Federal University of Rio Grande Sul. The aim of this work is to analyze the dictionary in its constitutive components, in order to identify the paths and challenges for writing the dictionary of our research. As a methodology, we apply in this study the principles of canonical structuring for semasiological dictionaries (macro, microstructure, and Front Matter) from Borba and Bugueño-Miranda (2012), Bugueño-Miranda (2007), Bugueño-Miranda and Farias (2013) and Seliste (2019). As a result, we recognized the need to better define the essential features of the work, such as the user profile and its function, in order to structure the canonical components according to the real needs of potential users. [ABSTRACT FROM AUTHOR]

Copyright of Domínios de Lingu@gem is the property of Dominios de Lingu@gem and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Contexto: O presente artigo analisa a primeira condenação de spoofing no Brasil pela CVM no Processo Administrativo Sancionador nº 19957.005977/2016-18. O spoofing é uma forma de manipulação do preço de valores mobiliários no Mercado de Capitais, caracterizada pela inserção de ordens artificiais de compra e venda, que são canceladas após milésimos de segundos e alteram o preço de negociação. Entretanto, a dificuldade de caracterização da conduta e as especificidades das negociações em alta frequência apontam para o risco de não se obter uma imposição (enforcement) adequada pela CVM. Objetivo e Metodologia: Nesse contexto, a partir do método dedutivo e de revisão bibliográfica, avalia-se a estrutura do mercado de capitais brasileiro a partir da disseminação das negociações de alta frequência sob a perspectiva da literatura econômica que trata da Microestrutura de Mercado. Assim, será possível fazer uma análise inicial da atuação da CVM na dissuasão do spoofing. A literatura de Law and Economics será utilizada para determinar se o padrão de punição pela CVM, no caso, é capaz de gerar a dissuasão da conduta e, de forma geral, ganhos efetivos para o mercado de capitais brasileiro. Conclusão: Observa-se a necessidade de desenvolvimento da matéria no Brasil para proporcionar o devido poder de dissuasão.

O presente artigo tem por objetivo apresentar uma análise da microestrutura dos verbetes “autismo” e “autista” em dicionários da Língua Portuguesa. Para tanto, foram utilizados cinco dicionários disponíveis online. A microestrutura das palavras-entrada “autismo” e “autista” foi analisada de forma descritiva e quantitativa, por meio de quadros comparativos, nos quais distribuímos as informações conforme registro nos dicionários. Pautamo-nos nos pressupostos teóricos de Biderman (2001), Garriga Escribano (2003), Medina Guerra (2003), Porto Dapena (2002), Welker (2004); bem como consideramos as contribuições advindas das produções científicas existentes no tocante ao Transtorno do Espectro Autista (TEA). Foi possível constatar que os verbetes “autismo” e “autista” em geral não apresentam suas definições conforme os conhecimentos mais recentes sobre o transtorno, bem como nem sempre mencionam a nomenclatura vigente “TEA”.

Resumo As cerâmicas porosas podem ser utilizadas nas mais diversas aplicações, como na indústria petroquímica e na área da saúde. No entanto, é difícil produzir cerâmicas com formas complexas usando processos convencionais. Neste trabalho, diferentes termoplásticos (PEBD, ABS e PLA) foram utilizados para a extrusão de filamentos com alumina submicrométrica. Estes filamentos foram extrudados com e sem ácido esteárico que, posteriormente, foram utilizados na manufatura aditiva para a impressão de estruturas porosas (scaffolds) pelo método de fabricação por filamento fundido. Foram obtidas imagens por microscopia eletrônica de varredura das amostras com e sem o ácido esteárico, antes e após a sinterização. Estas imagens mostraram que a presença do ácido esteárico reduziu a formação de defeitos, pois além de atuar como dispersante também facilitou a posterior remoção do veículo orgânico do scaffold, antes da sinterização final.

Copyright of Revista Opinião Jurídica is the property of Revista Opiniao Juridica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The third generation of advanced high strength steels have been developed to reach an excellent combination of strength and ductility, ensuring passengers' safety and good conformability for automotive components. For instance, there are the medium manganese steels, that contain 4 up to 12 wt.% Mn. They exhibit an ultra-fine microstructure with a significant amount of retained austenite. This phase transforms into martensite during mechanical loading due to the TRIP effect (Transformation Induced Plasticity), which provides an attractive combination of the properties previously mentioned. This work, carried out on a pilot scale, evaluated the influence of intercritical annealing temperature on the retained austenite volume fraction of a medium Mn steel. Additionally, it was determined the necessary thickness reduction to eliminate the discontinuous yielding through an additional skin pass step. Thus, the results showed a high austenite volume fraction for all analyzed conditions and the elimination of the discontinuous yielding after skin pass with thickness reductions above 5,5%. These outcomes lead to a significant strength and ductility increase, with a high potential application in the automotive industry. [ABSTRACT FROM AUTHOR]

The use of titanium dental implants for the total or partial rehabilitation of masticatory function is a common clinical practice in dentistry. These implants have osseointegration and are produced by machining titanium bars. The possibility of using additive manufacturing (MA) to make complex parts opens up the possibility of manufacturing custom implants. A disadvantage of the Ti alloy MA is that the products require heat treatment to relieve residual stresses arising from rapid cooling during manufacture. The present work aimed to produce dental implants of Ti-6Al-4V ELI by MA and to analyze the influence of sub-βtrans heat treatment on hardness and microstructure. The implants were subjected to heat treatments at temperatures of 400, 450, and 500 oC, which are inferior to the transformation of the α-β phase (sub-βtrans) of the alloy. Before and after the heat treatments, microstructure analyzes of the implants were performed by optical and scanning electron microscopy, the phase transformation temperatures were quantified by differential scanning calorimetry, the phases were identified by X-ray diffraction and the Vickers microhardness was determined. The microhardness and grain size data were subjected to statistical analysis. The results showed that all heat treatments changed the microstructure and microhardness of the implants. The most relevant changes in the microstructure were in the samples treated at 500 oC, indicating that this heat treatment induces greater stress relief without reducing the hardness of the implants. [ABSTRACT FROM AUTHOR]

In view of the large field of industrial application of bronze alloys, it becomes essential to carry out detailed metallurgical studies seeking the development of these alloys, specifically nickel-aluminum bronze, and one of the main technological fronts in which bronze is inserted is in aerospace applications, which require specific mechanical properties for the engineering material to support the efforts involved. One of the possibilities of reaching the properties is through the imposition of the variables present in the heat treatment, which influences the microstructure, due to the fact that bronze has martensitic transformation represented by β phase, and, consequently, on the mechanical behavior of the material. The objective of this work is to show the relationship between hardening by quenching, with subsequent tempering, and the mechanical properties generated in the aerospace bronze UNS C63000. The results show that the score in the order of 785, 835 and 885 °C followed by sudden cooling in water promotes an increase in the mechanical results, however, it is noted a gradual reduction in the percentage of α phase. [ABSTRACT FROM AUTHOR]

Copyright of Trabalhos em Lingüística Aplicada is the property of Universidade Estadual de Campinas - Portal de Periodicos Eletronicos Cientificos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Resumo A indústria de papel gera enorme volume de resíduo de lama de papel. Neste trabalho foi desenvolvido um novo suporte cerâmico poroso usando resíduo de lama de papel como matéria-prima alternativa. Os suportes cerâmicos foram produzidos por prensagem e sinterizados entre 1000 e 1200 ºC. A influência da incorporação do resíduo de lama de papel nas propriedades físicas e microestrutura sinterizada foi investigada. Os resultados indicaram que o resíduo de lama de papel atua como um agente formador de poro. Os suportes cerâmicos produzidos apresentaram massa específica aparente de 1,16 a 2,01 g/cm3, porosidade aparente de 14,6% a 46,7% e tensão de ruptura à flexão de 15,4 a 39,9 MPa. Análise microestrutural indicou que os suportes cerâmicos apresentaram estrutura morfológica altamente porosa. Tais resultados indicaram que suportes cerâmicos contendo até 30% em massa de resíduo de lama de papel têm potencial para serem empregados na fabricação de membranas de filtração.

Resumo: A Lexicologia, a Lexicografia, a Terminologia e a Terminografia, todas subáreas da Linguística, abarcam os estudos teóricos e a produção de dicionários, de vocabulários e de glossários. Este artigo objetiva o estudo da microestrutura de verbetes de especialidade em dicionários de Linguística e a proposta de um paradigma definicional para os termos linguagem e Linguística Descritiva. Para tanto, definimos o que são as microestruturas conforme as normas da ISO 1087 e as contribuições de Rey-Debove (1971), de Hartmann e James (2002), de Béjoint (2010) e outros. Abordamos as definições de outside matter, middle matter e back matter. Em seguida, exploramos os paradigmas informacional, definicional e pragmático, sem deixar de considerar o paradigma de formas equivalentes para dicionários bilíngues. A seguir, baseamo-nos nas normas ISO 1087 e na teoria de Barbosa (1995, 2001) para definir o que é um dicionário, um vocabulário e um glossário. Depois, fizemos um breve estudo comparativo entre alguns dicionários de especialidade pertencentes à área da Linguística. Nessas obras, fizemos a análise da microestrutura: dos enunciados lexicográficos e dos paradigmas definicionais, focando nos verbetes linguagem e fraseologismos do termo signo, e diferenciamos o que é a microestrutura de um dicionário e a de um glossário. Finalmente, após a exposição dos conceitos e análise das obras, propusemos padrões de microestrutura e definitórios, em diferentes áreas da Linguística, cujo público-alvo seria o alunado leigo dos Cursos de Letras. Palavras-chave: terminologia; terminografia; dicionários de especialidade; macroestrutura; microestrutura. Abstract: Lexicology, Lexicography, Terminology and Terminology, all sub-areas of Linguistics, encompass theoretical studies and the making of dictionaries, vocabularies and glossaries. This article aims to study the microstructure of specialized entries in dictionaries of Linguistics and the proposal of a definitional paradigm for the term language and sign phraseologies. To that end, we defined the microstructures according to ISO 1087 norms and the contributions of Béjoint (2010), Rey-Debove (1971), Hartmann and James (2002) and others. We approach the definitions of outside matter, middle matter and back matter. Next, we explore the informational, definitional and pragmatic paradigms, while considering the paradigm of equivalent forms for bilingual dictionaries. Then, we rely on ISO 1087 and Barbosa’s theory (1995, 2001) to define what a dictionary, a vocabulary and a glossary is. Afterward, we carried out a brief comparative study among some specialty dictionaries in the area of Linguistics. In these works, we analyzed the microstructure: lexicographic statements and definitional paradigms, focusing on the entries language and sign phraseologies, and we distinguished what the microstructure of a dictionary and a glossary is. Finally, after the exposition of the concepts and analysis of the works, we proposed a microstructure and a definition standard for the entries language and descriptive linguistics, in the area of Historical Linguistics, whose target audience would be the freshmen from Language and Literature courses. Keywords: terminology; terminography; specialized dictionaries; microstructure.

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Da mistura de solos com ligantes hidráulicos resultam materiais cimentados artificialmente através de ligações físicas (minerais resultantes da hidratação do ligante). A geometria das ligações é controlada pela quantidade de água usada no processo construtivo que, por sua vez, depende de requisitos de trabalhabilidade e da adição ou não de adjuvantes. Na compactação a quantidade de água é baixa e as ligações tendem a concentrar-se nos contactos entre as partículas, onde a água fica retida num solo não saturado. Na injecção a quantidade de água é alta (assim como a dosagem) e as ligações são dispersas. Discute-se de que forma a geometria das ligações resultante do processo de mistura afecta o comportamento hidro-mecânico de solos arenosos tratados com cimento Portland. Usa-se como exemplo os resultados de ensaios realizados em amostras de uma areia tratada com diferentes dosagens de cimento e relações água/cimento, que permitiram a caracterização do seu comportamento mecânico e hidráulico, e ainda ensaios não destrutivos para caracterização dessas ligações. Observa-se porosidade dupla quando as ligações são concentradas, o que afecta essencialmente as características hidráulicas. As características mecânicas dependem essencialmente da dosagem de cimento, mas a quantidade de água usada também afecta as características da pasta de cimento endurecida.

RESUMO 1

Copyright of Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental is the property of Revista Eletronica em Gestao, Educacao e Tecnologia Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Resumo A microencapsulação é um processo indicado para proteger substâncias que são susceptíveis à degradação ou redução da sua funcionalidade por causa de diferentes reações, por exemplo, oxidação, hidrólise, entre outras. O objetivo deste estudo foi avaliar o efeito da microencapsulação, usando como materiais de parede maltodextrina ou amido modificado, sobre a estabilidade de hidrolisados proteicos de okara. A pesquisa analisou a microestrutura, a capacidade antioxidante e a cor das amostras durante a estocagem dos pós por 120 dias a 35 °C. As micrografias obtidas por microscopia eletrônica de varredura indicaram que o processo de microencapsulação favoreceu a integridade física das partículas. A diferença de cor observada entre as amostras encapsuladas e não encapsuladas foi proveniente, provavelmente, da adição de materiais de paredes que contribuíram para a mudança da cor do pó obtido por spray drying. Os resultados indicaram que as microcápsulas obtidas por spray drying usando maltodextrina ou amido modificado mantiveram a cor dos pós e apresentaram boa habilidade em sequestrar o radical livre ABTS e teor de substâncias redutoras do reagente Folin-Ciocalteu durante a estocagem.

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The experimental and theoretical investigations of mechanical properties of porous materials are one of the priority areas of development of condensed matter physics. Diatomite ceramics can serve as a raw material for structural heat and sound insulating materials and additives to some types of cement, as a polisher for metals and marble. Diatomite-based ceramics are also used for thermal insulation in aluminum production. The foamdiatomite ceramics is a promising porous material. But the properties of diatomite ceramics are not well studied, which determines the relevance of the study. The main task of the present work is the investigation of porosity and elastic moduli of diatomite ceramics, as well as the effect of thermal treatment on its physical-mechanical properties. The work deals with studying mechanical properties of porous ceramics based on diatomite -- a sedimentary rock composed predominantly of shells with micro- and nanopores of 50 to 500 µm. From the results of studying the microstructure of porous diatomite-based ceramics, the average porosity of samples (~50%) was determined, and the values of static (35 to 45 GPa) and dynamic (0.3 to 0.8 GPa) elastic moduli were experimentally measured. It was found that the values of elastic moduli decrease as material porosity increases. The experiment showed that the elastic modulus of the considered high-porous material was two orders of magnitude less than that of the crystalline one. [ABSTRACT FROM AUTHOR]

Lexicology, Lexicography, Terminology and Terminology, all sub-areas of Linguistics, encompass theoretical studies and the making of dictionaries, vocabularies and glossaries. This article aims to study the microstructure of specialized entries in dictionaries of Linguistics and the proposal of a definitional paradigm for the term language and sign phraseologies. To that end, we defined the microstructures according to ISO 1087 norms and the contributions of Béjoint (2010), Rey-Debove (1971), Hartmann and James (2002) and others. We approach the definitions of outside matter, middle matter and back matter. Next, we explore the informational, definitional and pragmatic paradigms, while considering the paradigm of equivalent forms for bilingual dictionaries. Then, we rely on ISO 1087 and Barbosa's theory (1995, 2001) to define what a dictionary, a vocabulary and a glossary is. Afterward, we carried out a brief comparative study among some specialty dictionaries in the area of Linguistics. In these works, we analyzed the microstructure: lexicographic statements and definitional paradigms, focusing on the entries language and sign phraseologies, and we distinguished what the microstructure of a dictionary and a glossary is. Finally, after the exposition of the concepts and analysis of the works, we proposed a microstructure and a definition standard for the entries language and descriptive linguistics, in the area of Historical Linguistics, whose target audience would be the freshmen from Language and Literature courses. [ABSTRACT FROM AUTHOR]

Abstract The present work aimed to evaluate the effect of the antifreeze protein on the microstructure and physicochemical properties of hidroponic strawberries, evaluating the titratable acidity, pH, colour and optical microscopy before freezing both in natura (IN) and impregnated with the protein (IP), and after thawing without the protein (TWP) and impregnated (TIP) with the antifreeze protein (AFP Type I from fish) by vacuum impregnation. After thawing, the treatment was also compared in terms of drip losses. The antifreeze protein impregnated strawberries showed no statistical differences with respect to the physicochemical properties, but the drip loss was statistically lower from the thawed strawberries treated with the antifreeze protein. The vacuum impregnated thawed strawberries showed less damage to the microstructure. The cells of the thawed samples with antifreeze protein conserved the structure of the reference samples of in natura strawberry.

This work has characterized an original serpentinite sample and after calcination in a muffle furnace at 1200°C. Analytical techniques were used: chemical analysis, X-ray diffractometry (XRD), microstructures by SEM and EDS. The XRD confirmed the phyllosilicate minerals, lizardite and talc, as the main constituents of this sample, and magnetite in a smaller quantity. Thermogravimetry (TG and DTG) was performed up to 1450°C and the results showed a total mass loss of 12.15%, in addition to two peaks: lizardite at 645°C and talc at 729°C.To analyze the ferrous phases, Mössbauer spectroscopy was used, with spectra recorded at room temperature. In addition, the calcined sample was also analyzed at the very low temperature of 25K. These results have confirmed the phase composition, with the decreasing amount of magnetite and the significant presence of magnesioferrite. The dominant phases were forsterite and enstatite, both containing iron in their composition. By microstructure analysis, the morphological change of the particles was observed, with an expressive decrease of the fine fibers, for more rounded rod-like shapes indicating the beginning of the sintering process. [ABSTRACT FROM AUTHOR]

The aim of the present research was to evaluate differences in chemical properties and physical structure of yoghurt produced with milk from different species (sheep, cow, and goat). For each trial, whole raw sheep (S), cow (C), and goat (G) milk were used to manufacture 4L of yoghurts (Y) from each species (SY, CY, and GY, respectively). The SY demonstrated the greatest (P<0.05) values of total solids, protein, and lipid contents, reflecting on greater (P<0.05) firmness, apparent viscosity and water-holding capacity, and lower (P<0.05) syneresis index than CY and GY. Consequently, SY exhibited a more compact microstructure and homogeneous matrix with fewer pores. Furthermore, CY and GY microstructure contained a greater number of pores, which exhibited greater size heterogeneity than SY. Therefore, based on the evaluated physicochemical and microstructural properties of yoghurt, SY demonstrated the most desirable parameter values for dairy industry representing an alternative substitution for cow's milk yogurt. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Resumo Os objetivos deste trabalho foram a obtenção de uma ferrita de chumbo e cobre com a estrutura do espinélio, a caracterização da sua microestrutura e a determinação das suas propriedades magnéticas. A ferrita de cobre e chumbo é um material com baixa coercividade magnética, alta resistividade elétrica e alta permeabilidade magnética. Amostras com estequiometria PbxCu1-xFe2O4, com (x= 0, 0,1 e 0,2), foram produzidas pelo processo de metalurgia do pó e sinterizadas a 800 °C por 6 h em atmosfera ambiente. As caracterizações estrutural, microestrutural e magnética foram realizadas utilizando as técnicas de difração de raios X, microscopia eletrônica de varredura, magnetômetro de amostra vibrante e análise termogravimétrica magnética. Os resultados mostram que as amostras são formadas exclusivamente pela estrutura do espinélio tetragonal. As curvas de histerese mostram características de materiais magnéticos moles e sua magnetização de saturação aumentou com a concentração de chumbo. O valor da temperatura de Curie diminuiu com o aumento da concentração de chumbo.

Abstract In the cellulose industry the Kraft process is widely used to produce cellulose. This process generates huge volumes of inorganic solid wastes, including the grits waste. In Brazil, the final disposal of this solid waste is of high economical and environmental interest. The present work assesses the influence of the addition of grits waste on the densification behavior of soil-cement bricks. The raw materials used were soil, Portland cement, and grits waste. Soil-cement bricks containing up to 30 wt.% grits waste in partial replacement of Portland cement were prepared by uniaxial pressing and cured for 28 days. The following technological properties were determined: water absorption, compressive strength, and durability. The microstructure was evaluated by scanning electron microscopy and X-ray diffraction. The experimental results indicated that the addition of grits waste influenced positively the densification behavior of the soil-cement bricks. Moreover, the grits waste could be incorporated into the soil-cement brick composition up to 20 wt.% as a partial replacement of Portland cement.

Ceramic materials are of technical and commercial interest due to their chemical, mechanical and thermal performance, leading ceramics to meet many engineering requirements. Alumina (aluminum oxide) is one of the primary representatives of this class of materials because of its high fracture toughness, hardness and density, which enable its use in the production of highly critical parts. One such application involves protection against abrasion and erosion wear. The wear properties of a ceramic can be improved not only by controlling its material characteristics but also by controlling the fabrication process, which defines the material's microstructure. Many studies of the effects of the microstructure on these properties have been published. The objective of this study was to review the effects of the microstructure on the erosive wear resistance of alumina-based ceramics. Four factors that control the erosive wear of alumina were identified: (i) the effects of dopants on the diffusivity of the grain boundaries, (ii) the fabrication route, (iii) the sintering mechanisms and (iv) the alumina grain size. The published experimental results related to these topics are described and provide a clear understanding of the erosive wear of alumina.

When exposed to elevated temperatures, concrete suffers physicochemical changes, resulting in reduction of mechanical properties, cracking and spalling. These macroscopic changes are related to changes in the microstructure of concrete. In this paper, the microstructure of thermally damaged concrete from real-scale reinforced concrete columns was studied, using scanning electron microscopy (SEM) and x-ray diffraction (XRD). Two real-scale reinforced concrete columns, with different concrete mixtures, were exposed to ISO 834 fire standard curve for 4 hours. After heating, concrete core samples were drilled, sectioned and analyzed in different column section depths. Core samples from reference column not exposed to high temperatures, were also obtained. Macroscopic observations showed a change in the color of concrete exposed to high temperatures. SEM micrographs presented distinct changes in morphology, like coarsening, and the presence of cracks and voids. XRD diagrams showed a reduction of portlandite and presence of larnite as depth increases. [ABSTRACT FROM AUTHOR]

A Nickel superalloy, Inconel 625®, was studied in the current work. Friction Stir Welding was carried out with tool rotational speeds ranging from 1200 to 200 rpm and welding speed between of 1 mm/s. In addition, metallographic and microhardness analyzes were performed in the joints. The solid state process was effective and resulted in increased microhardness in the welded joints. Finally, it is suggested that a lower heat input leads to sound welds. Increasing the tool rotational speed (1200 rpm) achieved a higher heat input and porosity formation. [ABSTRACT FROM AUTHOR]

In a scenario of blast furnace slag shortage, the use of BOF slag (Blast Oxygen Furnace) as a partial substitute in cement production is a low cost alternative. In this paper, BOF (Blast Oxygen Furnace) slag samples were melted in an experimental electric arc furnace (EAF), with different modifiers materials (Al top dross reject, slag from FeSi iron alloy production, et al.) with different rates of additions, subject to differentiated cooling in specifically designed experimental apparatus. The objective was to search the formation of different phases formed during a process of BOF slag modification, for different materials additions containing Al2O3 and SiO2 and subjected to different cooling conditions. Modified slags, with basicity (CaO/SiO2) below 1.1 and Al2O3 contents less than 5%, subjected to cooling rates up to 21°C/s, favor the formation of crystalline phases; no amorphous phases were detected in this trial. Modified slag tests with basicity below 1.2 and Al2O3 content between 10.0% and 12.5% favor both the formation of crystalline (majority) and amorphous phases (between 25% and 30%). The influence of the cooling rate up to 21°C/s on amorphous phase formation in this trial was not conclusive. [ABSTRACT FROM AUTHOR]

To obtain a copper and niobium ferrite with the structure of spinel samples were produced by solid state reaction process stoichiometry NbxCu1-xFe2O4 (x = 0.0, 0.10 and 0.20) and sintered at 1000°C for 8 h and subsequent characterization of its microstructure and determine their magnetic properties. The structural characterizations, microstructural and magnetic were performed using the techniques of X-ray diffraction, scanning electron microscopy (SEM), vibrating sample magnetometer of and magnetic thermal analysis. The results showed that the sample with x = 0.00 was formed by the phase cubic and tetragonal spinel structure. The stoichiometry samples with x = 0.10 and 0.20 were formed exclusively by the phase cubic spinel structure and Nb2FeO6 phase with orthorhombic structure. The hysteresis curves showed soft magnetic material characteristics and its saturation magnetization increased with the concentration of niobium. As electrical permissivity measurements and impedance characterization of the samples, the range of 1 Hz to 10 MHz, suggest that the electrical characteristics of the samples suffer greater influence of the grain boundary. [ABSTRACT FROM AUTHOR]

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Copyright of Domínios de Lingu@gem is the property of Dominios de Lingu@gem and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)