Dielectric behaviour of Hf-doped CaCu3Ti4O12 ceramics obtained by conventional synthesis and reactive sintering

CaCu3(Ti4xHfx)O12 ceramics (JC = 0.04, 0.1 and 0.2) were prepared by conventional synthesis (CS) and through reactive sintering (RS), in which synthesis and sintering of the material take place in one single step. The microstructure and the dielectric properties of Hf-doped CCTO (CCTOHf) have been studied by XRD, FE-SEM, AFM, Raman and impedance spectroscopy (IS) in order to correlate the structure, microstructure and the electrical properties. Samples prepared by reactive sintering show slightly higher dielectric constant than those prepared by conventional synthesis in the same way than the pure CCTO. Dielectric constant and dielectric losses decrease slightly increasing Hf content. For CCTOHf ceramics with x> 0.04 for CS and x> 0.1 for RS, a secondary phase HfTi04 appears. As expected, the reactive sintering processing method allows a higher incorporation of Hf in the CCTO lattice than the conventional synthesis one.

D-depth profiling in as-implanted and annealed Li-based breeder blanket ceramics

In future power plants (i.e. DEMO), the nuclear fusion of hydrogen isotopes will be used for energy production. The behaviour of hydrogen isotopes in lithium-enriched ceramics for breeder blankets (BBs) is one of the most important items to be understood. In this paper we present the chemical, microstructural and morphological features of Li4SiO4, Li2TiO3 and a third ceramic candidate with a higher Li:Si proportion (3:1), implanted with D at an energy of 100 keV and at room temperature at a fluence of 1 × 1017 cm−2. The D depth-profile in as-implanted and annealed ceramics (at T ⩽ 200 °C) was characterised by Resonance Nuclear Reaction Analysis (RNRA). The RNRA data indicate that the total amount of D is retained at room temperature, while annealing at 100 °C promotes D release and annealing at T ⩾ 150 °C drives D to completely desorb from all the studied ceramics. D release will be discussed as a function of the microstructurural and morphological features of each material.

Mechanical properties up to 1900 K of Al2O3/Er3Al5O12/ZrO2 eutectic ceramics grown by the laser floating zone method

Directionally solidified Al2O3–Er3Al5O12–ZrO2 eutectic rods were processed using the laser floating zone method at growth rates of 25, 350and 750 mm/h to obtain microstructures with different domain size. The mechanical properties were investigated as a function of the processing rate. The hardness, 15.6 GPa, and the fracture toughness, 4 MPa m1/2, obtained from Vickers indentation at room temperature were practically independent of the size of the eutectic phases. However, the flexural strength increased as the domain size decreased, reaching outstanding strength values close to 3 GPa in the samples grown at 750 mm/h. A high retention of the flexural strength was observed up to 1500 K in the materials processed at 25 and 350 mm/h, while superplastic behaviour was observed at 1700 K in the eutectic rods solidified at the highest rate of 750 mm/h

Precursores funcionalizantes de poros à base de alginato para obtenção de cerâmicas bioativas

A complexidade de desenvolver novas tecnologias para aplicações em reconstituição óssea se deve à necessidade de combinar várias propriedades químicas e físicas para que o material proporcione o desempenho almejado. Particularmente, em aplicações que visam osteogênese, os enxertos sintéticos devem ser bioativos, possuir porosidade com volume, geometria e interconectividade de poros controlados, além de ter boas propriedades mecânicas, dentro de limites relativamente rígidos. Por essa razão, o recobrimento de materiais bioinertes com cerâmicas bioativas se tornou o foco da presente pesquisa. O objetivo desse estudo foi desenvolver um novo método de produção de enxertos cerâmicos com macroporosidade funcionalizada, onde a formação e o revestimento dos poros são realizados em uma única etapa. Foi realizado o estudo de recobrimento com vidro bioativo e fosfato de cálcio. Para isso, agentes porogênicos na forma de grânulos (de 600 μm a 2 mm de diâmetro) foram sintetizados pelo método da gelificação de uma solução aquosa de alginato de sódio gotejada em solução de nitrato de cálcio (0,5 M), com incorporação de outros elementos para a formação de biovidro ou fosfato de cálcio. Esses grânulos foram conglomerados a um vidro ou alumina em pó, formando um compósito, que foi tratado termicamente para sinterização e formação de poros. No caso da matriz vítrea, a sinterização ocorreu com cristalização simultânea e concorrente. As cerâmicas resultantes foram caracterizadas por microscopia óptica e eletrônica de varredura, sendo possível observar a formação de macroporos aproximadamente esféricos (de 600 μm a 2 mm de diâmetro) revestidos internamente por uma camada de material com possível composição bioativa.

The Composition and Drivers of Energy Prices and Costs in Energy-Intensive Industries: The Case of Ceramics, Glass and Chemicals. CEPS Special Report No. 85, 27 March 2014

In May 2013, the European Commission received a mandate from the European Council to “to present an analysis of the composition and drivers of energy prices and costs in Member States, with a particular focus on the impact on households, SMEs and energy intensive industries, and looking more widely at the EU's competitiveness vis-à-vis its global economic counterparts”. Following such mandate and in view of the preparation by the Commission of a Communication and a Staff Working Document, DG Enterprise and Industry commissioned CEPS to carry out a set of studies aimed at providing well-grounded evidence about the evolution and composition of energy prices and costs at plant level within individual industry sectors. A team of CEPS researchers conducted the research, led by Christian Egenhofer and Lorna Schrefler. Vasileios Rizos served as Project Coordinator. Other CEPS researchers contributing to the project included: Fabio Genoese, Andrea Renda, Andrei Marcu, Julian Wieczorkiewicz, Susanna Roth, Federico Infelise, Giacomo Luchetta, Lorenzo Colantoni, Wijnand Stoefs, Jacopo Timini and Felice Simonelli. In addition to an introductory report entitled “About the Study and Cross-Sectoral Analysis”, CEPS prepared five sectoral case studies: two on ceramics (wall and floor tiles and bricks and roof tiles), two on chemicals (ammonia and chlorine) and one on flat glass. Each of these six studies has been consolidated in this single volume for free downloading on the CEPS website. The specific objective was to complement information already available at macro level with a bottom-up perspective on the operating conditions that industry stakeholders need to deal with, in terms of energy prices and costs. The approach chosen was based on case studies for a selected set (sub-)sectors amongst energy-intensive industries. A standard questionnaire was circulated and respondents were sampled according to specified criteria. Data and information collected were finally presented in a structured format in order to guarantee comparability of results between the different (sub-)sectors analysed. The complete set of files can also be downloaded from the European Commission’s website: http://ec.europa.eu/enterprise/newsroom/cf/itemdetail.cfm?item_id=7238&lang=en&title=Study-on-composition-and-drivers-of-energy-prices-and-costs-in-energy-intnsive-industries The results of the studies were presented at a CEPS Conference held on February 26th along with additional evidence from other similar studies. The presentations can be downloaded at: http://www.ceps.eu/event/level-and-drivers-eu-energy-prices-energy-inten...

Summaries of physical research in research in metallurgy, solid state physics and ceramics.

"January 1957 (TISE Issuance Date)."

Summaries of physical research in research in metallurgy, solid state physics and ceramics.

"July 1959 (TIS Issuance Date)."

Summaries of the UDAEC basic research programs in metallurgy, solid state physics and ceramics.

"January 1964 (DTIE Issuance Date)."

Summaries of the UDAEC basic research programs in metallurgy, solid state physics and ceramics : (fiscal year 1964)

"January 1965 (DTIE Issuance Date)."

Asiatic Art, VII century B.C.-XVIII century A.D., including sculpture in bronze & stone, ceramics, miniatures and textiles.

Exhibition and sale at the American Art Galleries, New York.

Summaries of the UDAEC basic research programs in metallurgy, solid state physics and ceramics.

"June 1961 (OIT Issuance Date)."