Ceramics - Science topic

This work evaluated the resistance of LaPO4 ceramics to CMAS attack at 1250oC and explored their interaction mechanisms. The chemical reaction between molten CMAS and LaPO4 involves two stages leading to formation of a continuous inner layer and outer polyhedron grains, which effectively prevents the infiltration of CMAS. The reaction layer in this...

Here, High Energy Ball Milling (HEBM) is used to prepare Cr doped ZnO (Zn 1-x Cr x O, x = 0-0.04) nanoceramics and their electrical behaviour is studied in detail. The X-ray diffraction suggests a hexagonal wurtzite structure. The Rietveld refinement XRD pattern of the sample calcined at 900 • C suggests that up to 4 at% of Cr can be doped into the...

Petrographic Analysis of Ceramics from Swifterbant S3 (Prov. Flevoland / NL) (c. 4300–4000 cal BC) This article presents a petrographic analysis of 18 ceramic sherds from Swifterbant S3. The Swifterbant pottery is rather homogeneous. Most vessels were made from a clay containing diatoms, spongia needles and mica and were tempered with stone materia...

Reversible protonic ceramic electrochemical cells (R-PCECs) are ideal, high-efficiency devices that are environmentally friendly and have a modular design. This paper studies BaFe 0.6 Zr 0.1 Y 0.3 O 3− δ (BFZY3) as a cobalt-free perovskite oxygen electrode for high-performance R-PCECs where Y ions doping can increase the concentration of oxygen vac...

In this work, we present phase and structural investigation of pure and Li (=0.08) modified perovskite structured 0.480. [Ba (Zr0.25Ti075)O3]-52(Ba0.75Ca0.25)TiO3 ceramics for versatile applications.Pure and Li modified BZT-BCT ceramic materials were synthesized by hydrothermal method. Powder X-ray diffraction studies showed single and pure rhomboh...

Con el objetivo de inducir efectos bactericidas en la superficie de una cerámica sanitaria esmaltada en condiciones propias de la industria, se incluyeron diferentes concentraciones de TiO2 en una composición estándar de referencia y se realizaron variaciones en el tratamiento térmico. Análisis ópticos de espectrofotometría UV/VIS y espectrofluorim...

Translucent, monoclinic-free, novel calcia-stabilised zirconia ceramics were developed utilising conventional (pressureless) sintering. The 10 mol% CaO-doped zirconia (10CaSZ) ceramic depicted a maximum transmittance of 81% at 600 nm for a 0.6 mm thick pellet while for 3 mol% CaO-doped zirconia (3CaSZ) phase-pure tetragonal system, the value was re...

En el año 2006 nace el programa de voluntariado para asistencia en vivienda ASUA-Construye de la Universidad Anáhuac México. En el que los alumnos construyen cada semestre para familias de bajos recursos de Huixquilucan cinco viviendas llave en mano a partir de un prototipo a base de paneles prefabricados de poliestireno expandido, que aunque son e...

The presence of moisture in buildings can be responsible for the development of pathological manifestations. Through computer simulations, it is possible to predict how the material will behave when exposed to different conditions and, for this, the hygrothermal characteristics of the construction elements are very important. In Brazil, there is a...

Persistent, catastrophic tailings facility failures and declining water resources in many major mining jurisdictions are generating intense scrutiny by investors and stakeholders. This paper summarizes a case study for the development of an alternative tailings management concept, which includes the implementation of a novel process flowsheet to ge...

This paper reports the preliminary results from three seasons of excavations in the Christian cemetery by the Tunisian-British Bulla Regia Archaeological Project. In 2017–2019, excavations in, and around, the Late Antique church in the western cemetery uncovered a complex funerary landscape with a variety of different tomb types, including mosaic c...

NiCoCrAlY coatings are commonly used as bond-coat in thermal barrier coatings due to their excellent high-temperature oxidation resistance and suitable thermal expansion coefficient between the superalloy substrate and ceramic top layer. Previous studies have shown that the NiCoCrAlY coatings prepared by cold spray (CS) exhibit excellent comprehens...

Class II ceramics are a material with high permittivity but low reliability of their capacitance and bias voltage due to high the temperature sensitivity of their dielectric permittivity. In this work, a BST-based (Ba0.9−xSrxCa0.1)TiO3·0.03(Bi2O3·3TiO2) (x = 0.2, 0.25, 0.3, 0.35, 0.4) composition with Y5U characteristics was investigated through co...

Na indústria cerâmica é de extrema importância o desenvolvimento de formas eficientes para processamento de matéria-prima, cuja dureza e resistência a altas temperaturas representam suas principais características. Dentre elas encontra-se o moinho planetário, máquina composta por 2 ou 4 jarros que apresenta rotações em sentidos variados. O alto cus...

RESUMO: A impressão 3D de materiais cerâmicos se destaca por permitir a fabricação de peças complexas e personalizadas com menor custo. Esta pesquisa apresenta a formulação, preparo e caracterização das matérias primas cerâmicas fotopolimerizáveis para uso em impressoras 3D comerciais não especializadas em cerâmica. Três pós cerâmicos de alumina fo...

Resum: Presentem dues noves inscripcions funeràries d'època romana que s'han trobat en el curs de sengles intervencions arqueològiques portades a terme en els darrers anys a la comarca de la Safor. La primera és una estela que es va trobar completa al centre terrisser de Pardines (Beniarjó) i la segona és un fragment de placa trobat a la vil·la del...

Cationic substitutions and sintering temperature both are crucial variables in modifying the structural and magnetic properties of M-type hexaferrites. The effect of the cationic substitutions on M-type BaFe10−xAl2MgxO19 hexaferrites is examined in the current work. An XRD analysis reveals that Fe2O3 phases are present as an impurity in all of the...

Las representaciones artísticas de formas espectrales han adquirido determinadas formas tradicionales perfectamente reconocibles en el mundo occidental, ya se trate de figuras humanas cadavéricas, a veces mostrando partes traslucidas de sus cuerpos, o formas voluminosas envueltas en mortajas que ocultaban su cuerpo y rostro. De hecho, algunos de su...

Crack propagation in ceramics is a highly quick, complex, and nonlinear process that occurs under thermal shock. It is challenging to directly observe the evolution process of cracks in experiments due to the high speed and unpredictability of crack propagation. Based on the phase-field fracture method, a phase-field numerical model combined with t...

Thermal oxidation (TO) has proven to be a cost-effective and efficient technique to engineer the surfaces of titanium and its alloys to achieve enhanced surface properties. The benefits of TO treatment in enhancing the tribological properties of titanium have been demonstrated by many investigators. However, most of the reported tribological studie...

The weakened pinning effect of oxygen vacancies due to the introduction of Mn on the transfer from polarization nanoregions to normal ferroelectric domains was investigated through the component design. The 0.85K0.5Na0.5NbO3-0.15Bi0.5Zn0.5Ti0.5O3-xMnO2 (abbreviated with KNN-BZT-xMn, x=0 and 0.1, i.e. KNN-BZT and KNN-BZT-Mn) ceramics were synthesize...

We fabricated porcelain ceramics embedded with WO3 nanoparticles (NPs) for radiation shielding applications. The linear attenuation coefficients were experimentally determined to study the efficiency of the manufactured samples against gamma rays. When the thickness increases from 0.5 to 2 cm, there is a reduction in the photon transmission through...

Metal particles play a significant role in inducing surface flashover of insulators. Alumina ceramic is commonly utilized as an insulator in electrical vacuum equipment due to its high insulation and corrosion resistance properties. To ensure the safe operation of such equipment, it is imperative to investigate the impact of metal particles on the...

Ceramics are considered to be candidate materials for galvanising pot bearing materials due to their excellent corrosion resistance in many molten metals. Galvanising pot roll bearings must have excellent wear resistance, and, therefore, it is important to understand the wear behaviour of prospective bearing materials. This study investigates the f...

Traditional isothermal aging treatments could not balance the relationship between mechanical properties and corrosion resistance of ultra-high-strength Al–Zn–Mg–Cu alloys. Therefore, the effect of non-isothermal aging (NIA) treatments on the microstructure and properties of TiC-TiB2 (BC) ceramic particles-reinforced spray-formed 7055 aluminum allo...

Atualmente, o mercado oferece diversas opções de cerâmica para o clínico, como dissilicato de lítio, porcelana feldspática, porcelana feldspática reforçada com leucita e dissilicato de lítio reforçado com zircônia. Esses tipos de cerâmica possuem alta proporção de vítreo. matriz que produz resultados altamente estéticos e excelente adesão ao ciment...

This study focuses on optimizing the composition and firing temperature of porcelain tiles using statistical analysis techniques. A full factorial design, including model adequacy checking, analysis of variance, Pareto charts, interaction plots, regression model, and response optimizer is employed. The key factors were the Seger ratios of SiO2/Al2O...

In Vitro Comparative of the Cutting Efficiency and Smear Layer of Ceramic Burs, Conventional Tungsten Carbide Burs and Diamond Stone.

The interdisciplinary project "The study of tunnels and caves in Teotihuacan", directed by Linda R. Manzanilla deals with Epiclassic and Late Postclassic occupations in the Teotihuacan Valley, as a result of the extensive excavations of four quarry tunnels to the east of the Pyramid of the Sun. The second volume includes the obsidian instruments of...

Recent excavations at Hrisosotira, on the western Black Sea coast, have yielded an abundance of archaeological material dating from late antiquity. The most spectacular find is a closed complex labelled Building 18, where three coin hoards have been found, one gold and two copper, as well as a rich inventory including scales, weights, a bronze lamp...

Resumo O artigo tem por objetivo descrever a prevalência de capacidade para o trabalho inadequada e analisar os fatores associados a essa condição em trabalhadores da indústria de revestimentos cerâmicos. O estudo caracteriza-se como transversal, foi realizado com trabalhadores de uma empresa produtora de revestimentos cerâmicos no sul do estado de...

2. Effect of Caries Removal Using Ceramic Bur on the Microtensile Bond Strength of Etch and Rinse and Self Etch Adhesive Systems

Esse artigo possui o objetivo de analisar as características de interferência/influência jesuítica dos Sítios Arqueológicos Alvim (Pirapozinho – SP), Castelinho (Presidente Epitácio – SP) e Taquaruçu (Sandovalina – SP), por meio da cadeia operatória de La Salvia e Brochado (1989) e o modelo tecnotipológico de Faccio (1992), além da revisão bibliogr...

Zirconia based oxygen conductors are state of the art solid electrolytes used for solid oxide fuel cell applications. In this study, we investigated zirconia double-doped with aluminium and scandium oxide. The Al0.04Sc0.06Zr0.9O1.95 electrolyte was prepared using Pechini method. In the 300–800 K temperature range, this material's structure is cubic...

Direct methane protonic ceramic fuel cells are promising electrochemical devices that address the technical and economic challenges of conventional ceramic fuel cells. However, Ni, a catalyst of protonic ceramic fuel cells exhibits sluggish reaction kinetics for CH4 conversion and a low tolerance against carbon-coking, limiting its wider applicatio...

2023 г. Д.А. Кириченко, А.М. Агаларзаде В статье представлены образцы керамики эпохи раннего железа, обнаруженной на поселении Худутепе, которое располагается на территории Джалилабадского района. В ходе археологических раскопок в культурном слое и во время сбора подъемного материала была выявлена, так называемая «Дворцовая керамика» государства Ур...

The ion diffusion phenomenon in ferroelectric-dielectric composite ceramics will deteriorate its dielectric properties. In this paper, Ba0.5Sr0.5TiO3-CuGa2O4 composite ceramics were prepared at different sintering heating rates. The phase composition, microstructure and dielectric properties were tested and analyzed. The effects of grain growth and...

Since January of 2010 pollen sampling and analysis of the water system structures underlying ancient Jerusalem's City of David (Ir David) excavations have been an ongoing project sponsored jointly by the universities of Haifa and San Diego. These have included Channel II, the Siloam Tunnel, the Siloam Pool, the Stepped Street and herein, as a final...

Background In clinical practice, control of the marginal fit of fixed dental prostheses is hindered by evaluation method, which needs to be further improved to increase its clinical applicability. This study aimed to quantitatively analyze the absolute marginal discrepancy of three-unit ceramic fixed dental prostheses fabricated by conventional and...

Since January of 2010 pollen sampling and analysis of structures and the ceramic artifacts recovered from them within excavations throughout the Galilee region have been an ongoing project sponsored jointly by the Israeli Antiquities Authority and the universities of Haifa and San Diego. This paper focuses primarily on fossil pollen recovered by po...

The paper presents the interdisciplinary results of three ceramic fragments from dolia‑type vessels, discovered in the archaeological excavations from Curtain X area of the late Roman citadel of Ibida. The samples were analyzed by OM, SEM‑EDX and μ‑FTIR techniques in order to identify some archaeometric characteristics, related to the nature of the...

Dynamic crack involves instabilities promoted by either external perturbation or intrinsic front oscillation. In an effort to decipher fracture surface markings of brittle materials, crack roughness of Wallner lines promoted by shear waves and surface corrugations induced by spontaneous front oscillations was investigated with silicon single crysta...

تعد الهوية البصرية والمحافظة عليها من أبرز القضايا المطروحة في وقتنا الحاضر وذلك لأهميتها وخطورتها لأن اهمالها يشكل تهديداً في المحافظة عليها، وجاءت هوية المدينة على مر الزمن نتيجة النشاط الحضاري والثقافي للإنسان في مجتمع ما، ومحافظة قنا في أمس الحاجة للتعبير عن هويتها وحضاراتها وتراثها وثقافتها حتى توثق لها هوية بصرية مبدعة ذات بصمة بهدف الترويج ل...

Burial urns and lids found in the Carthage tophet precinct play a pivotal role in our understanding of material trajectories. Significant differences in macroscopic features present problems as to where and how these vessels were made. In general, issues in sourcing north African ceramic materials stem from their compositional homogeneity, having m...

In many commercially utilized ferroelectric materials, the motion of domain walls is an important contributor to the functional dielectric and piezoelectric responses. This paper compares the temperature dependence of domain wall motion for BaTiO3 ceramics with different grain sizes, point defect concentrations, and formulations. The grain boundari...

The advent of zirconia ceramics with excellent mechanical, biomechanical and optical properties has made it an attractive metal-free substitute for titanium implants. Both animal and human studies have documented shortcomings with titanium implants. A review of the current literature on 3 iterations of zirconia implant designs has been challenging...

In this work, β-FeOOH precursors were grown on flat Al2O3 ceramic matrix by a hydrothermal-assisted sol-gel composite method, followed by heat treatment to obtain α-Fe2O3/Al2O3 photo-Fenton catalysts (FA). The effect of heat treatment temperature on the microstructure and photo-Fenton performance of α-Fe2O3/Al2O3 photo-Fenton catalysts was studied...

The article engages with the issue of changes in the technology of producing clay vessels based on the example of early medieval pottery from Wielkopolska. The focus was on the issue of the introduction of innovations and the process of technological change from the perspective of the techniques used and their importance in a broader cultural and s...

Dicing and filling is the most commonly used method to fabricate the piezoelectric composite by replacing part of the piezoelectric ceramics with the polymer. The dicing quality affects the composite performance, and the dicing mechanism is not clear now. In this study, a theoretical dicing mechanism for PZT-4H ceramics is introduced and validated...

Apresenta‑se o estudo do espólio cerâmico proveniente de uma escavação de minimização de impacte, realizada em 2015/2016, no sítio arqueológico de Carvalhais. Apesar de as estruturas exumadas não terem dado informação relevante, a pequena coleção cerâmica reúne condições para fornecer dados a ter em conta na caracterização da cultura material da al...

Thermoluminescent (TL) properties of monoclinic zirconium dioxide ceramics were studied in order to assess the possibility of their use for measuring high doses (on the order of kGy) of pulsed electron beams (130 keV). Two types of samples were used: those synthesized by sintering in an electric furnace at T = 700–1700 °C and those synthesized in a...

A recently emerged XRD-based cosα residual stress measurement method, which utilizes imaging plate detectors, has attracted special attention from both academia and industry. There are uncertainties about to which extent the method could be used and about the accuracy of the measurements when analyzing industrial components. This work investigates...

Solid state proton conductors are promising materials for various electrochemical applications. LaScO3 - based oxides are representatives of the proton-conducting oxides with perovskite structure, alternative to conventional cerates and zirconates of alkaline-earth elements. These oxides exhibit a sufficient level of proton conductivity with a comb...

The style of ancient ceramics has always been one of the most important factors affecting the sales of antique ceramic products. Although it has certain rules, due to the complexity of current product design and the limitations of designers in the design process, intelligent algorithms are needed to assist in design. In response to the diversity of...

Reductions in the cost of transporting manufactured goods have been an important element in economic development in the recent past, and previous research suggests that the Roman period in Britain also saw substantial reductions in such costs. The authors investigate how far it is possible to measure changes in transport costs by considering the sp...

Apresenta‑se um conjunto de dados, provenientes de recentes trabalhos e de pesquisa em arquivos de anteriores escavações, relativos à presença de uma oficina tardo‑antiga de produção cerâmica em Conimbriga. O forno, principal elemento reconhecido dessa oficina (escavado em 1966) é caracterizado como um forno de câmara simples de ventilação descende...

Ceramics offer several attractive properties of industrial relevance, e.g. high strength and hardness, low thermal conductivity, and chemical inertness in critical environments. There is thus interest among researchers to improve the fracture toughness of ceramics, which is generally low and considered a major drawback. Numerous experimental studie...

Resumen El objetivo de este artículo es examinar cómo se construyeron las tipologías de la cerámica a torno de dos de los yacimientos arqueológicos de la Primera Edad del Hierro más importantes del Sudeste de la península ibérica: por un lado, el estable-cimiento indígena de Peña Negra (Crevillent, Alicante) y, por otro, el fenicio de La Fonteta (G...

The Sn–Zr filler metal is developed to braze Ti–13Nb–13Zr (TNZ) alloy and ZrO2 ceramic for biomedical field. The impact of brazing processing parameters on the interfacial microstructure as well as mechanical properties is comprehensively examined and discussed. The typical interfacial microstructure of the joints is TNZ/Ti6Sn5/Ti6Sn5 + ZrSn2 + β-S...

In this paper, the microstructures of nanocomposite ceramic tool materials are represented through Voronoi tessellation. A cohesive element model is established to perform the crack propagation simulation by introducing cohesive elements with fracture criteria into microstructure models. Both intergranular and transgranular cracking are considered...

BaFe0.5Ta0.5O3ceramics has been successfully prepared by a solid state reaction method and structural analysis revealed that single perovskite phase was obtained in the ceramic sample. Room temperature magnetodielectric and magnetoimpedance properties of ceramics were investigated. Variations in the dielectric permittivity, loss tangent and impedan...

In multinary oxides such as perovskites ABO3, an applied voltage causes charged mobile species (ions, electrons) to move according to their electrochemical mobilities. For different electrochemical mobilities of the cations kinetic unmixing takes place, and after some time even kinetic decomposition may occur. Both kinetic effects are detrimental t...

A giant negative electro-caloric effect is present in PLZST ceramics over a wide range of temperatures at high fields for the new generation of the solid-state refrigeration process. The structural phase purity, ambiguity of phases, and coexistence of dual structural phase modulation over the substitution were identified clearly with the help of di...

Purpose of Study: To examine the roughness of slots of three ceramic brackets. Materials and Methods: Three ceramic bracket types (Encore, Reflections and Inspire ICE). The bottom of each slot of every bracket was selected for evaluation and pictures were taken by optical microscopy at magnification (20x) for a general estimation of the roughness....

A large body of literature within the additive manufacturing (AM) community has focused on successfully creating stable tungsten (W) microstructures due to significant interest in its application for extreme environments. However, solidification cracking and additional embrittling features at grain boundaries have resulted in poorly performing micr...

The main aim of this study was to produce hybrid metal matrix composites (HMMCs) using the stir casting method, by integrating different ceramic particles in a 3:2 ratio. The results of the scanning electron microscope (SEM) study revealed a uniform distribution of the reinforcing particles throughout the matrix of the hybrid metal matrix composite...

Studying the interrelationships between industrial development and urban form is key to understanding land development and spatial dynamics in any industrial region. Taking Morbi (Gujarat, India), as a case study, this research examines how the development of the ceramic industry has influenced urban morphology over the years. For this research, a...

In this paper, a novel 95Ag-2.5Ge-2.5Si (in wt %) filler is utilized for brazing yttria-stabilized zirconia (YSZ) electrolytes and commercial Crofer 22H interconnects for solid-oxide fuel cells’ (SOFCs) sealing application. Before brazing, surface metallization is applied on YSZ and Crofer 22H substrates to improve the wetting performance of the fi...

This article presents the influence of ecological measures, i.e., the addition of effective microorganisms and silver compounds to lubricating oil, on the operating parameters of an internal combustion engine. The basic diagnostic parameters of a reciprocating engine that determine its technical condition are described. In the Materials and Methods...