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El conocimiento que tenemos sobre el entorno marítimo de la ciudad de Gadir/Gades durante la Antigüedad se ha visto incrementado exponencialmente en los últimos años gracias a diversos trabajos de investigación desarrollados en la bahía, destacando entre ellos las prospecciones y sondeos arqueológicos realizados en La Caleta y los bajos adyacentes (2008-2010), zonas en las que no se habían obtenido resultados con las aplicaciones de nuevas tecnologías. El resultado fue la localización e identificación de una serie de yacimientos evidenciados por concentraciones de material, mayoritariamente de época fenicio-púnica, republicana y altoimperial. En este trabajo se presenta una panorámica de las evidencias cerámicas recuperadas en este proyecto, en concreto aquellas correspondientes a la etapa republicana de Gades. Esto permitirá estudiar la dinámica de emisión y recepción de productos a partir de los nuevos datos aquí aportados.

Ceramic sherds from the archaeological site of Suta, Leyva Valley, Colombia, have been dated by the electron paramagnetic resonance (EPR). The Ti-H center, generated by radiation in quartz, was detected by EPR and used to determine the age of the ceramic sherds studied here. The annual dose rate (AD) received by the pottery was evaluated from the contributions of external and internal radiation sources. Two dates were obtained from the absolute chronological data of the samples taken from the excavated archaeological units: 665.3 ± 130 and 1048.8 ± 110 AD years. This indicates an extended settlement period of 380 years for the two excavated sites. [ABSTRACT FROM AUTHOR]

The aim of the study is to assess the effect of accelerated aging on high translucency zirconia, through an in vitro investigation on phase transformation and fracture resistance. Blocks of conventional zirconia (Y-TZP N=05) and high translucency zirconia (HTZ N=05) were sectioned to generate specimens with dimensions of 12mm x 1.2mm. The specimens were evaluated for morphological analysis using a Scanning Electron Microscope (SEM) and structural analysis using X-Ray Diffraction (XRD), before and after thermal aging for 10,000 cycles with baths (5°C±1°-55°C±1°). Following aging, the experimental groups underwent biaxial flexural strength testing. One-way ANOVA (p<0.05) was employed. Morphological analysis post-aging revealed an increase in grain size in both groups: in the Y-TZP group, from 762.69nm to 1,215.25nm; in the HTZ group, from 671.56nm to 768.44nm. Chemical analysis confirmed the presence of Zirconium and Oxygen in both ceramics. XRD analysis revealed distinctive post-aging behavior, indicating a potential phase change in the Y-TZP group. Mechanical strength showed that Y-TZP presented a higher value compared to HTZ, with a statistically significant difference (p=0.000). Accelerated aging in high translucency zirconia does not seem to cause phase changes, presenting grain sizes similar to the non-aged condition. Conversely, conventional zirconia exhibited changes in grain size and post-aging morphological condition, yet still demonstrated mechanical superiority compared to high translucency zirconia. [ABSTRACT FROM AUTHOR]

The transparent relaxor ferroelectric ceramics of the system lanthanum modified lead magnesium niobate (PLMN-13PT) have been investigated for a variety of electro-optic, properties; good electro-optic switching times and modest half-wave voltages. In this work, the dependence of microstructural, structural, dielectrical, optical, and electro-optical properties in function of Rare Earth (RE = Tm3+, Nd3+, Yb3+, Er3+ and Ho3+) has been reported. PLMN-13PT:RE with excellent properties were obtained, highlighting the electrical, optical, and electrooptical properties, suitable for the fabrication of multifunctional devices. The most prominent or important feature is the largest quadratic Electro-optic coefficient achieved ((9.37 ± 0.39) × 10−16 m2/V2) corresponding to PLMN-13PT:Ho transparent ceramics. This result in addition to the electrical and photoluminescence properties becomes a promising alternative to building multifunctional devices. Resumen: Las cerámicas ferroeléctricas relajantes transparentes del sistema niobato de plomo y magnesio modificado con lantano (PLMN-13PT) han sido investigadas por una variedad de propiedades electroópticas; buenos tiempos de conmutación electroóptica y modestos voltajes de media onda. En este trabajo se ha informado de la dependencia de las propiedades microestructurales, estructurales, dieléctricas, ópticas y electroópticas en función de las tierras raras (RE = Tm3+, Nd3+, Yb3+, Er3+ y Ho3+). Se obtuvieron cerámicas del sistema PLMN-13PT:RE con excelentes propiedades, destacando las eléctricas, ópticas y electroópticas, aptas para la fabricación de dispositivos multifuncionales. La característica más destacada o importante es el mayor coeficiente electroóptico cuadrático alcanzado ((9,37 ± 0,39) × 10-16 m2/V2) correspondiente a la cerámica transparente PLMN-13PT: Ho. Este resultado, además de las propiedades eléctricas y de fotoluminiscencia, convierte a este sistema en una alternativa prometedora para la construcción de dispositivos multifuncionales.

Bi2Ca2−xNaxCo2Oy materials with x = 0 ≤ x ≤ 0.125, have been prepared either by sintering through the classical ceramic method, or textured using the laser floating zone technique. XRD results have shown that Bi2Ca2Co2Oy phase is the major one, independently of the Na content, in both kind of samples. SEM studies have shown a drastic microstructural modification between sintered and laser-textured materials. Na-doping increases density and grain sizes in sintered materials, while it enhances grain alignment in laser-grown materials. Moreover, it decreases secondary phase content in all cases. Electrical resistivity is also drastically reduced through texturing, when compared to the sintered samples, and Na-doping further decreases it. The lowest values determined in the laser-textured samples (26 mΩ cm at 650 °C) are around 40% lower than the best in sintered materials. On the other hand, S has been only slightly affected for Na-doping or processing method for all samples. Consequently, the highest power factor at 650 °C (0.18 mW/K2 m) has been obtained in laser-grown 0.075Na-doped samples, which is around 20 and 70% higher than the measured in undoped laser-textured samples, and sintered ones, respectively. Resumen: Se han preparado materiales de composición Bi2Ca2-xNaxCo2Oy, con x = 0 ≤ x ≤ 0,125, por el método de estado sólido, además de texturarlos mediante la técnica de zona flotante inducida por láser. Los resultados de XRD han mostrado que la fase Bi2Ca2Co2Oy aparece como la mayoriraria, independientemente del contenido de Na, en ambos tipos de muestras. Los estudios SEM han encontrado una drástica modificación microestructural entre materiales sinterizados y texturados. El dopado con Na aumenta la densidad y el tamaño de grano en materiales sinterizados, mientras que mejora la orientación de los granos en materiales texturados. Además, disminuye el contenido de fases secundarias en todos los casos. La resistividad eléctrica disminuye drásticamente con el texturado, en comparación con las muestras sinterizadas, mientras que el dopado con Na la disminuye aún más. Los valores más bajos determinados en muestras texturadas (26 mΩ cm a 650 °C) son alrededor del 40% menor que los mejores datos publicados en materiales sinterizados. Por otro lado, S solo se ha visto afectado levemente, tanto por el dopado como por el método de procesado. En consecuencia, el máximo factor de potencia a 650 °C (0,18 mW/K2 m) se ha obtenido en muestras dopadas con 0,075 Na y texturadas, que es alrededor de un 20 a un 70% superior al medido en muestras texturadas sin dopar y sinterizadas, respectivamente.

A core region is the first place for expected shifts in archaeological materials before, during, and after political changes like state emergence and imperial consolidation. Yet, studies of ceramic production have shown that there are sometimes limited or more subtle changes in the ceramic economy throughout such political fluctuations. This article synthesizes recent efforts to address political economic changes via geochemical characterization (neutron activation analysis; NAA) in the Lake Pátzcuaro Basin in western Mexico. This region was home to the Purépecha state and then empire (Tarascan; ca. AD 1350–1530), one of the most powerful kingdoms in the Americas before European arrival. The combined ceramic dataset from four sites in the region result in eight geochemical groups. Our analysis indicates that the region experienced long-term and relatively stable ceramic production that was not substantially altered by the emergence of the state and empire. In addition, we find evidence for (1) dispersed, localized production; (2) long-lived compositional ceramic recipes; and (3) a complex ceramic economy with differential community participation. We discuss why documenting local ceramic production and craft production more generally is important for the study of past political economies. [ABSTRACT FROM AUTHOR]

Este artigo analisa a deposição de cerâmicas em contextos funerários da Idade do Ferro bretã. O enfoque será dado à região de Yorkshire durante os séculos IV-II a.C., discutindo dados obtidos em um total de cento e vinte e três sepultamentos. O artigo começa com uma discussão sobre os contextos dos achados cerâmicos, incluindo uma discussão de sinais de usos prévios dos artefatos em ritos de comensalidade. Em seguida, aborda o uso de estratégias mnemônicas durante os sepultamentos, com foco particular na quebra intencional de vasos. Em terceiro lugar, a discussão examina, ainda, os perfis das pessoas sepultadas com tais artefatos, em particular no tocante ao seu sexo e idade. Nesse sentido, procura indicar a existência de certos padrões de distribuição — particularmente entre indivíduos do sexo feminino em idade adulta—, variável significativamente conforme a faixa etária em ambos os sexos. O artigo argumenta, por fim, que a deposição de cerâmicas em sepultamentos indica uma realidade de relativa fluidez e compartilhamento entre os gêneros na esfera funerária. Paralelamente à análise central, a discussão oferece também uma avaliação crítica do debate historiográfico sobre a estética das cerâmicas da Idade do Ferro bretã.

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Copyright of Brazilian Dental Science is the property of Brazilian Dental Science Journal-ICT-UNESP 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.)

En los numerosos conjuntos cerámicos de la Edad del Hierro recogidos en Alcácer do Sal, tanto en la necrópolis del Olival do Senhor dos Mártires, como en el poblado correspondiente (Castillo) y en el santuario de la Travessa do Rato, en el área ribereña, los platos, (de engobe rojo, de cerámica gris y de cerámica común) son una presencia constante. Muchos corresponden a modelos “clásicos” y así bien conocidos en el mundo orientalizante peninsular. Otros, en cambio, tienen una morfología muy particular, que se desarrolla en el siglo V a.n.e., pudiendo considerarse una evolución local de los platos de engobe rojo de origen fenicia.

Actualmente, la estética dental presenta un papel relevante dentro de las relaciones interpersonales y la autoestima de los pacientes, es por eso que la demanda de tratamientos estéticos y conservadores son cada vez más frecuentes en la consulta dental, esta demanda compromete a los profesionales a una mayor preparación para identificar los procedimientos más adecuados a ejecutarse. Para el odontólogo es un reto conseguir una completa armonización e integración de los tratamientos efectuados en el sector anterior y más aún cuando se requiere reemplazar un único elemento dentario. El presente reporte de caso tiene por objetivo describir un caso de rehabilitación de alta complejidad de un incisivo central superior fracturado, cuyas características de color y forma fueron recreadas a través de un correcto intercambio de información entre el odontólogo y el técnico dental, obteniendo una corona de disilicato de litio con una excelente mimetización.

Ca3Co4O9 + xwt.% TiC (x = 0, 0.25, 0.5, 0.75, and 1.0) polycrystalline thermoelectric ceramics have been prepared through the classical ceramic route. XRD characterization has demonstrated that all samples are mainly composed by the Ca3Co4O9 phase, while microstructural observation has shown that no reaction between both components has been produced. Moreover, TiC particles are well distributed for small additions, and start to agglomerate from 0.75 wt.% content. Density measurements showed that nearly no changes have been produced by TiC addition and nearly the whole porosity appears as open one. Furthermore, electrical resistivity decreases up to 0.75 wt.% addition, increasing for higher content. On the other hand, Seebeck coefficient has been maintained unchanged in all samples. In spite of an irregular behaviour of thermal conductivity with temperature, it tends to decrease when the temperature is raised, displaying the lowest values for the 0.25 wt.% samples. These data led to an increase of about 40% in ZT values at 800 °C for samples with 0.25 wt.% addition, when compared with the pure ones. Finally, linear thermal expansion coefficient is decreased when TiC content is increased, which can be exploited to fit the thermal expansion coefficients of all the components used to build a power generation thermoelectric module. Resumen: Se han preparado cerámicas de composición Ca3Co4O9 + x% en peso de TiC (x = 0, 0,25; 0,5; 0,75, y 1,0) utilizando el método clásico de estado sólido. La caracterización por XRD mostró que la fase termoeléctrica Ca3Co4O9 aparecía como mayoritaria. Las observaciones microestructurales determinaron que no se produce reacción entre esta fase y las partículas de TiC. Estas partículas aparecen bien distribuidas cuando hay pequeñas adiciones y comienzan a aglomerarse a partir del 0,75% en peso. Las medidas de densidad indicaron que este parámetro no se modifica con la adición de TiC y, además, que se produce una porosidad de tipo abierto. La presencia de TiC modifica la resistividad eléctrica de forma que disminuye hasta el 0,75% en peso de TiC, aumentando para contenidos mayores, sin afectar el coeficiente de Seebeck. La conductividad térmica muestra un comportamiento irregular, pero tiende a disminuir al aumentar la temperatura, alcanzando los menores valores en muestras con 0,25% en peso de TiC. Estos resultados llevaron a un aumento del 40% en los valores de ZT a 800 °C en muestras con 0,25% TiC en peso, comparados con los medidos en muestras sin TiC. Finalmente, el coeficiente de dilatación lineal disminuye al aumentar el contenido de TiC, lo que puede utilizarse para ajustar los coeficientes de dilatación de todos los componentes al construir un módulo termoeléctrico de generación de potencia.

This paper analyses the deposition of ceramics in funerary contexts of Iron Age Britain. The study focuses on the Yorkshire region during the 4th-2nd centuries BC, drawing on data obtained from a total of one hundred and twenty-three burials. The paper begins with a discussion of the contexts of the ceramic finds, including an exploration of the artefacts' previous uses in relation to commensality rites. It next addresses the use of mnemonic strategies during burials, with a particular focus on the intentional breaking of vases. Thirdly, the discussion delves into the profiles of the people buried with ceramics, with particular regard to sex and age. In this vein, it seeks to indicate the existence of certain patterns of distribution -- particularly among adult females -- which vary significantly according to the age of death among both sexes. The paper ultimately concludes that the deposition of ceramics in burials indicates a reality of relative fluidity among genders in the funerary sphere. Alongside the central analysis, the discussion also provides a critical assessment of the historiographical debate on the aesthetics of British Iron Age pottery. [ABSTRACT FROM AUTHOR]

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Here, we consider the last decades of ceramic manufacture among the Pawnee in the Central Great Plains, using petrographic analysis to explore raw material availability and use at the Kitkahahki Town site (14RP1). Historical documents reveal tremendous regional pressures and conflicts in the Kitkahahki Town area during its occupation in the late eighteenth and early nineteenth centuries-processes that could have altered or restricted the movement of women outside village boundaries. Contact-era Pawnee pottery from Kitkahahki Town exhibits atypical paste textures, atypical inclusions, or both. At least one potter used atypical materials available immediately adjacent to the village, which suggests that ceramic raw material collection was at least occasionally adjusted to reduce risk. Petrographic analysis contributes to our understanding of Indigenous communities in colonial settings, particularly to questions of technological change and landscape use when both were intensely negotiated and rapidly changing. [ABSTRACT FROM AUTHOR]

Introducción. El objetivo de la investigación consistió en emplear nanopartículas de arcillas, sales de fosfatos de calcio y cerámicas, combinados con sustratos fluorogénicos y cromogénicos, para acortar significativamente el período de diagnóstico microbiológico. Métodos. Se seleccionaron combinaciones de bases nutritivas, co-enzimas, co-factores que aceleran el desarrollo y metabolismo microbiano, se acoplaron estos componentes a nanopartículas y sustratos fluorogénicos y cromogénicos para obtener diferentes nanocompuestos. Las nanopartículas y los nanocompuestos se caracterizaron en su composición, estructura y funcionalidad con cepas aisladas de microorganismos y en muestras clínicas, aguas, entre otras. Resultados. Las nanopartículas y los agregados de halositas, bentonita, tierra silícea, hidroxiapatitas, de fosfatos cálcicos y zeolitas, mostraron elevadas relación superficie/volumen, porosidad y rugosidad de la superficie, con tamaños de partículas y de poros del orden nanométrico. Se combinaron extractos e hidrolizados de proteínas con un conjunto de sales y co-enzimas que posibilitaron la rápida multiplicación celular y la síntesis de enzimas microbianas detectadas en sólo minutos por la degradación de una combinación de sustratos fluorogénicos y cromogénicos. Se acoplaron las nanopartículas y agregados a los demás componentes obteniendo diferentes estructuras que permitieron reducir el tiempo de incubación para la detección, identificación, aislamiento y recuento a mínimos de 10 min a 60 min en muestras directas. Como conclusión se logró una plataforma de diagnóstico rápido de microorganismos empleando nanopartículas y agregados de arcillas y cerámicas acoplados a sustratos que revelan la actividad enzimática en solo minutos.

Currently, CAD / CAM systems have been increasingly used in Dentistry, however due to the characteristic of the technique, since it is milled from a ceramic block, some flaws, such as fractures, become a challenge after the piece is cemented. To avoid the complete replacement of the part, the technique through intraoral repair of the fractured region is ideal for these cases. There are several protocols for this technique, this study aims to review the literature regarding the techniques and protocols for ceramic repair of the CAD / CAM system. A literature review was carried out on the Pubmed database using the terms Ceramic repair, Adhesive and Composite resin searching for studies published in the period from 2000 to 2020. 104 articles were found, after reading 32 articles were selected because they presented a greater correlation with the present study. There was unanimity among the authors about the importance of a surface treatment on the ceramic to be repaired, 70% of them still indicated the roughness with drills and conditioning with hydrofluoric acid due to the ease of the technique and good result. The combination of several surface treatments in the same region to be repaired produces better tensile strength. The use of the silane agent in a separate step presents better bonding strength results when compared to the universal type adhesive system with silane incorporated in the formula. [ABSTRACT FROM AUTHOR]

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Copyright of Acta Odontologica Latinoamericana: AOL is the property of Acta Odontologica Latinoamericana 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 Journal of Clinical Dentistry & Research is the property of Dental Press International 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.)

A wide variety of dental ceramics is launched every year. Therefore, clinicians should constantly study and update themselves to correctly indicate these materials. This cross-sectional study aimed to assess the association of dentists' academic aspects with their knowledge and the indication of dental ceramics for metal-free restorations. All the dentists from private clinics who affirmed to perform prosthetic treatments on their patients in a Southern Brazilian city were personally invited to this research to avoid dropouts. Participants answered questions related to their knowledge of different dental materials, their information sources and usage frequency of ceramic materials, and related to their academic training/education. Chi-square tests were performed to evaluate the association among the outcomes (knowledge of different materials, information sources considered for material selection and their frequencies of use) and exposure variables (time since graduation and post-graduation degree). Significant associations were also submitted to Chi-square residual analysis. A response rate of 73.3% was reached. The most known and used materials were Y-TZP and porcelain veneered zirconia, respectively, whereas the least known was leucite-based ceramic. The majority of the professionals with at least 25 years since graduation claimed not to know lithium disilicate or leucite-based ceramics, and a significant number of these professionals allow the laboratory prostheses technician to choose the restorative material. In addition, most of dentists with no post-graduation said they did not have knowledge about leucite and lithium disilicate. It was evidenced that continuing education plays an important role in the dentists' attitudes regarding ceramic materials. [ABSTRACT FROM AUTHOR]

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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.)

Introduction: the purpose of this study was to assess the mechanical behavior of lithium disilicate, alumina, and zirconia-based ceramic restorations, as well as metal-ceramic restorations, under static and dynamic load, in an upper anterior fixed site. Methods: four models of fixed partial dentures (FPD) were designed, representing alumina, zirconia, and metal-ceramic two-layered systems and a lithium disilicate monolithic system, with a 9 mm2 connector. The variables included were elastic modulus, Poisson’s ratio, and ultimate tensile strength. A static load of 100 N was applied up to 800 N, as well as a dynamic load of 100 and 200 N, calculating von Mises stress and maximum and minimum principal stresses. Results: all models showed a greater concentration of stress under static and dynamic load on the connector region, without exceeding the maximum tensile stress of metal and ceramic structures. The two-layered models showed greater stress concentration on the veneering ceramic compared with the structure. Conclusions: all stresses concentrated on the connector region, producing failure risk at this point of the structures. The veneering ceramic has a greater probability of failure in all two-layered models. The disilicate model can be considered as an alternative for clinical use. The metal-ceramic dentures showed the best distribution on the connector compared to all other models, confirming that they are the gold standard.

Se presentan las excavaciones realizadas en la escombrera del taller de vasos de alabastro de Rodén (Zaragoza). Se exponen las características de la actuación, se analiza la estratigrafía y cronología del yacimiento, los rasgos técnicos del tipo de artesanía documentada y se estudian los elementos asociados, especialmente las cerámicas, con producciones prehistóricas, medievales y modernas registradas a lo largo de una secuencia que se extiende desde el siglo v a.C. hasta el xviii. Como resultado ha sido posible determinar la naturaleza del hallazgo —una escombrera de desechos de producción—, fijar la cronología del taller en la primera mitad del siglo xi, coincidiendo con el desarrollo de la taifa de Zaragoza, y explicar la evolución del yacimiento entre los siglos xiv y xviii a partir de las cerámicas entre las que resultan especialmente significativas las producciones esmaltadas.

Atualmente há uma busca crescente pela melhoria da estética do sorriso juntamente com a evolução dos materiais restauradores odontológicos que vem aperfeiçoando e melhorando técnicas adesivas minimamente invasivas, sendo de suma importância para os profissionais da área odontológica, compreender e dominar sobre esse assunto. As restaurações do tipo faceta confeccionadas em resina composta ou em cerâmicas odontológicas são procedimentos estéticos amplamente indicados principalmente quando há alterações na morfologia da estrutura dental, na coloração e textura de superfície além de divergências de simetria e proporção. Este trabalho visa abordar através de uma revisão de literatura sobre restaurações diretas em resina composta e indiretas em cerâmica realizadas em dentes anteriores apontando suas principais vantagens, desvantagens fatores de sucesso e principais motivos de falha que irão influir sobre sua longevidade clínica. Pode-se concluir que as restaurações diretas e indiretas em dentes anteriores apresentam um alto índice de sucesso clínico em longo prazo, sendo o motivo de falha das facetas de resina composta relacionadas à estética, já as facetas em cerâmica apresentaram como principal falha a fratura da restauração. Entretanto quando bem indicadas e executadas a taxa de sobrevida destes procedimentos é considerada alta.

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Copyright of Conservar Património is the property of Associacao Profissional de Conservadores-Restauradores de Portugal 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 Boletin de Geologia is the property of Universidad Industrial de Santander 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.)

El conocimiento de la ocupación visigoda y paleoislámica en el valle del Ebro resulta un tanto difuso, más por falta de investigaciones y por la escasa visibilidad de los asentamientos, que por un efectivo despoblamiento. En este artículo presentamos los resultados de nuestras investigaciones en el yacimiento de Los Pedregales, en la provincia de Huesca, un sas cronologías (romanos, altomedievales, modernos…) junto con numerosas estructuras pétreas en un área completamente alterada por procesos erosivos. Una minuciosa prospección y la excavación de algunas estructuras en el marco de un estudio geoarqueológico, nos ha permitido explicar la ocupación principal del yacimiento como un campo de silos datado entre los siglos vi y ix, que aporta una nueva referencia para la comprensión de los paisajes rurales antiguos y las comunidades campesinas dispersas que los ocupan. En el artículo se describen e interpretan las estructuras, se estudian los materiales más relevantes, especialmente los cerámicos, y se contextualiza el yacimiento con relación al poblamiento y los procesos históricos que afectan a este territorio.

Resumo Composições contendo dois diferentes tipos de resíduos, vidro de garrafas transparentes, VGT (50-70%), e lodo de estação de tratamento de efluentes, ETE (30-50%), e formador de poros, CaCO3 (2-10%), foram preparadas para a produção de isolantes térmicos para fins estruturais. As matérias-primas das composições formuladas foram, em uma etapa posterior, misturadas, compactadas uniaxialmente a 40 MPa e, após secagem (110 °C/2 h), queimadas entre 750 e 1000 °C com patamares de 15 a 60 min. As matérias-primas e os materiais obtidos foram caracterizados do ponto de vista de suas propriedades químicas, físicas e microestruturais. Os resultados obtidos mostraram que é possível produzir isolantes térmicos, a partir de composições otimizadas contendo 70% de VGT, 30% de lodo de ETE e 5% de CaCO3, queimados entre 750 e 1000 °C/60 min, os quais apresentaram porosidades entre 3 e 62% com condutividades térmicas entre 1,25 e 0,5 W/m.K e com resistência à compressão entre 8,7 e 5,4 MPa. Os materiais obtidos são fortes candidatos em aplicações estruturais tais como painéis para isolamento térmico, os quais requerem uma combinação adequada de condutividade térmica, porosidade e resistência mecânica.

Este artigo refere-se à análise do material arqueológico do Sítio Mandaguari encontrado no distrito de Floresta do Sul, no município de Presidente Prudente/SP. Essa avaliação dá conta de que o sítio encontrado é de natureza litocerâmica, sendo que foram encontrados urnas, vasilhames e artefatos líticos polidos e lascados. Pode-se inferir tratar-se de duas populações pré-históricas, uma de coletores/caçadores autores das pontas de projétil e outra de lavradores ceramistas.

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.

Objective: The objective of this study was to evaluate the effect of different surface treatments on the pigmentability of the ceramic after immersion in staining solution. Materials and Methods: 44 disks of 10 mm radius and 3 mm thickness were made. Samples were randomly assigned among 4 experimental groups (n=11) receiving surface treatment according to the different groups M, H, B, L. (n=10) were distributed for color evaluation and Roughness (RU) and a sample of each group used for scanning electron microscopy (SEM) analysis. For (RU), the data were subjected to ANOVA on ranks (a=0.05), and for the color ANOVA a factor (a=0.05). In the microphotographs of the surface, a qualitative/descriptive analysis was carried out. Results: In the (RU) compared before and after immersion for each group, no statistical difference was observed (p> 0.05). When comparing the types of polish before immersion, a difference was observed between the L group with the other M, H, B (p <0.05). In the analysis of the groups after immersion, there was a difference of group L with B and M (p <0.05). When comparing the color alteration, after immersion, there was a difference between all the ANOVA groups (p <0.05). In the analysis by (SEM) all groups had partially porous surfaces; however, the varnishes produced the best result groups H and B. Conclusions: The texture of the surface is an important factor in the pigmentability of ceramics. the varnished materials showed less color alteration. [ABSTRACT FROM AUTHOR]

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.)

Copyright of Journal of Clinical Dentistry & Research is the property of Dental Press International 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 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.)

Copyright of Implant Dentistry is the property of Lippincott Williams & Wilkins 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.)

A tenacidade à fratura, K IC, é uma importante propriedade dos materiais cerâmicos, pois ela mede a resistência ao início da propagação de trinca. O problema é selecionar o método adequado para determinar K IC, já que existem vários, cada um com suas particularidades. Por comodidade, escolhe-se o método da indentação, IF, que apresenta certos inconvenientes, principalmente para cerâmicas porosas, Sendo o método mais adequado, o SEVNB. Nesse trabalho são mostrados resultados de K IC para três materiais: carbeto de silício (SiC), alumina (Al2O3) e um a base de argila, uma telha cerâmica. Os resultados mostraram que os valores de K IC são maiores quando é utilizado o método IF, sendo que quanto mais porosa é a cerâmica mais difícil é a aplicação desse método, e que o método SEVNB, pode ser aplicado com êxito. Os resultados de K IC, medidos pelo método SEVNB são 3,8 MPa.m½, 2,5 MPa.m½ e 0,4 MPa.m½ para SiC, Al2O3 e telha, respectivamente.

Compósitos polímero/cerâmica à base de poli (fluoreto de vinilideno), PVDF, e cerâmicas ferroelétricas de titanato zirconato de chumbo modificado com lantânio, PLZT, foram sintetizados a partir da dispersão de partículas de cerâmica na solução polimérica. A temperatura de secagem dos materiais, para a evaporação dos solventes usados na dissolução da matriz polimérica e na mistura com as partículas cerâmicas, foi um parâmetro controlado visando obter compósitos com a maior concentração de fase β, na qual o polímero apresenta ferroeletricidade. Através dessa rota, foi possível obter filmes de compósitos com grande fração de fase β para todas as temperaturas de secagem, apesar de constar na literatura a pouca existência dessa fase em filmes de PVDF preparados a partir da solução, com altas temperaturas de secagem. Observou-se que a concentração da fase β nos compósitos se mostrou não somente uma função da temperatura de secagem do material, mas também uma função da concentração de dopantes cerâmicos, de modo que independente da temperatura, se conseguiu obter concentrações de fases β superiores a 90%, com concentrações de cerâmica acima de 20% em peso.

Copyright of eHumanista is the property of Professor Antonio Cortijo-Ocana 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.)