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1
Custer, Jay F. "Problems and Prospects in Northeastern Prehistoric Ceramic Studies." North American Archaeologist 8, no. 2 (October 1987): 97–123. http://dx.doi.org/10.2190/8rg1-qq9q-5mkj-hl83.
Повний текст джерелаАнотація:
Three major research topics can be addressed using Northeastern ceramic data. First, different technological developments are seen in the earliest ceramics. Flat-bottomed wares develop in the Middle Atlantic and coiled, conoidal wares are earliest in New England. Second, the Abbott Farm and Delmarva Adena complexes of the central Middle Atlantic can be distinguished from surrounding Early and Middle Woodland complexes on the basis of ceramics; social complexity may be related to ceramic traits. Finally, Late Woodland ceramic design motifs and design “grammars” can be used to distinguish ethnic groups and study population movements throughout the Northeast.
2
de Matos, Jefferson David Melo, Guilherme Rocha Scalzer Lopes, Daher Antonio Queiroz, Leonardo Jiro Nomura Nakano, Nathália Carvalho Ramos Ribeiro, Adriano Baldotto Barbosa, Lilian Costa Anami, and Marco Antonio Bottino. "Dental Ceramics: Fabrication Methods and Aesthetic Characterization." Coatings 12, no. 8 (August 22, 2022): 1228. http://dx.doi.org/10.3390/coatings12081228.
Повний текст джерелаАнотація:
This study aimed to describe different staining protocols for the main dental ceramics. A bibliographic search was conducted in the main health databases PubMed and Scholar Google, in which 100 studies published were collected. In vitro and in silico studies, case reports, and systematic and literature reviews, on ceramic materials, were included. Therefore, articles that did not deal with the topic addressed were excluded. Ceramics can be classified into glass-matrix ceramics (etchable), polycrystalline (non-etchable), and hybrid ceramics. In this context, different fabrication methods, method indications, and characterization layers can be used for each ceramic group and numerous protocols differ according to the choice of material. Several ceramic systems are available, thus professionals in the prosthetic area need constant updates on dental ceramic restorations and their proper characterizations.
3
Siripuram, Rajesh, P. Satya Gopal Rao, and Suresh Sripada. "Comparative studies of structural and optical properties of Nb2O5–Sb2O3–TeO2 glass and glass-ceramics." Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B 63, no. 3 (2022): 65–85. http://dx.doi.org/10.13036/17533562.63.3.02.
Повний текст джерелаАнотація:
A new, transparent antimony-tellurite glass and glass-ceramic systems doped with Nb2O5 have been prepared by using the conventional melt quenching method and heat treatment process, respectively. Various physical, optical and structural studies were reported through XRD, TEM, SEM, ultraviolet-visible, Raman, infrared and ESR investigations. XRD analysis of glass and glass-ceramic samples revealed their amorphous and crystalline natures, respectively. The Williamson-Hall approach was used to determine the average crystallite size of synthesised glass-ceramics and the values were found to be in the range of 23 to 85 nm. The SEM result reveals that glass-ceramics contain perspicuous and haphazardly distributed nanoclusters possessing sizes in the range of 45 to 120 nm. TEM analysis shows the size of particles in the glass-ceramics is in the range of 10 to 90 nm. The Eopt of the glass system has decreased from 2·873 to 2·606 eV, whereas in the glass-ceramic system it is observed to increase from 1·340 to 1·748 eV. Raman and infrared spectral analysis confirm the existence of various structural units such as TeO4, TeO3+1, TeO3, NbO6, NbO4, SbO3 in the glass and glass ceramic systems.The ESR spectral analysis reveals that the (Δg‖/Δg^) parameter seems to decrease from 4·444 to 2·453 in glass sytem, whereas in glass-ceramics it is observed to increase from 2·357 to 4·188. Glass transition temperature and onset crystalline temperatures are influenced by the Nb2O5 in both glass and glass-ceramic samples.
4
Zhang, Lijian, and Guangfu Liu. "Ceramic Shape Design Based on Intelligent Space Simulation Technology." Journal of Sensors 2022 (June 2, 2022): 1–9. http://dx.doi.org/10.1155/2022/5251436.
Повний текст джерелаАнотація:
With the development of the times, intelligent space simulation technology has gradually emerged in the design of ceramic forms, and the development of modern ceramics has gradually transformed into artistic development. The development of ceramics must conform to the design trend, adjust the rhythm, and seek development opportunities. Organic design opens up a green channel for ceramics and integrates into the lives of today’s people. This paper mainly discusses the external form of ceramics and studies from two levels of curve form and bionic form. Through the intelligent space simulation technology, the shape design of ceramics is studied, and the optimal shape of ceramics is obtained, which enables people to have a better understanding of ceramic art.
5
Beena, P., and HS Jayanna. "Dielectric studies and AC conductivity of piezoelectric barium titanate ceramic polymer composites." Polymers and Polymer Composites 27, no. 9 (June 17, 2019): 619–25. http://dx.doi.org/10.1177/0967391119856140.
Повний текст джерелаАнотація:
In this work, ceramics barium titanate (BT) polymer composites were prepared with BT/polyvinyl alcohol (PVA) having a ceramic concentration of 10, 30, and 50% by weight using solution casting method. The prepared thin film samples were characterized by X-ray diffraction for phase analysis. Scanning electron microscope (SEM) studies on composite films revealed ceramic crystallites are well dispersed in the polymer matrix. The dielectric constant ( εr) and the AC conductivity at room temperature and at different frequencies (100 Hz–5 MHz) of the piezoelectric composites with different concentrations were investigated. The result shows that the dielectric constant of ceramic-PVA composites was found to increase as ceramic concentration increases and the dielectric loss tangent decreased with increasing concentration. AC conductivity of the composites increased with increasing frequency.
6
Reedy, Chandra L., Jenifer Anderson, Terry J. Reedy, and Yimeng Liu. "Image Analysis in Quantitative Particle Studies of Archaeological Ceramic Thin Sections." Advances in Archaeological Practice 2, no. 4 (November 2014): 252–68. http://dx.doi.org/10.7183/2326-3768.2.4.252.
Повний текст джерелаАнотація:
AbstractThin-section petrography is a crucial tool for the study of archaeological ceramics, and in recent years, image analysis has emerged as a powerful quantitative enhancement of that tool. Exploratory applications of image analysis to archaeological ceramic thin sections, and related work by sedimentary geologists, have indicated its usefulness to the field. In this paper, we first present the results of experimental work testing the consistency and reproducibility of image analysis. We identify procedures for fast and reliable analysis of thin sections using laboratory-prepared ceramic specimens of simple clay-sand systems. We then show how those procedures can be slightly modified to accommodate more complex archaeological specimens. We conclude with a discussion of the role of image analysis within the overall context of thin-section petrography of ceramic materials, as one among a repertoire of techniques, adding quantitative data and increasing the usefulness of ceramic thin sections for addressing archaeological research questions.
7
Deshpande, V. K., and V. U. Rahangdale. "Study of PbTiO3-Based Glass Ceramics Containing SiO2." ISRN Ceramics 2012 (November 4, 2012): 1–5. http://dx.doi.org/10.5402/2012/823903.
Повний текст джерелаАнотація:
Glass samples with composition 50PbO : 25TiO2 : (25-X) B2O3 : XSiO2 (with X = 0, 1.5, 2.5, 3.5, and 5 mol%) were prepared by conventional quenching technique. These glass samples were converted to glass ceramics by the two-stage heat treatment schedule. Formation of ferroelectric lead titanate phase in the glass ceramics was confirmed from the XRD. The density, CTE, and dielectric constant of the glass and glass-ceramic samples were measured. The glass-ceramic sample containing 2.5 mol% SiO2 exhibited the highest dielectric constant. The SEMs of glass-ceramic samples were studied. The P-E hysteresis loop studies also revealed the highest remnant polarization for this sample, which has a potential for being developed for practical applications.
8
Chaklader, A. C. D., G. Roemer, W. N. Hardy, J. H. Brewer, J. F. Carolan, and R. R. Parsons. "STUDIES ON CERAMIC SUPERCONDUCTORS." Advanced Ceramic Materials 2, no. 3B (July 1987): 556–61. http://dx.doi.org/10.1111/j.1551-2916.1987.tb00119.x.
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9
Alisin, Valery V. "Improving the Tribological Properties of Ceramic Dies." Key Engineering Materials 887 (May 2021): 339–44. http://dx.doi.org/10.4028/www.scientific.net/kem.887.339.
Повний текст джерелаАнотація:
The article is devoted to tribological studies of a ceramic composite with a zirconia-based die in order to replace carbide wire drawing dies with ceramic. Sliding friction was done according to the scheme finger-disk without lubrication and with lubrication. The wear rate and friction coefficients were determined, on the basis of which it is proposed to produce portage dies-blanks from zirconium ceramics. The influence of sintering temperature on the mechanical properties of ceramics, especially cracking resistance, was studied. The optimum sintering temperature was determined by the criterion of fracture toughness. The formation of defects after the final firing was investigated. It was found that sintering at a temperature of 1600 ° C is more promising. An trial batch of zirconium ceramic dies showed positive results in the process of drawing copper wire in industrial situations.
10
La Duc, Elizabeth, and Angela Chang. "Analysis and Replication Studies of Prehistoric Chinese Ceramics from the Qijia Culture." MRS Advances 2, no. 35-36 (2017): 1849–67. http://dx.doi.org/10.1557/adv.2017.156.
Повний текст джерелаАнотація:
ABSTRACTEleven ancient Chinese ceramics from the early Bronze Age Qijia culture (c. 2200 – 1600 BCE) in the collection of the Harvard Art Museums were the subject of an interdisciplinary research project to explore questions about manufacturing techniques, specifically details of formation and decoration. While the Qijia culture, centered in the Gansu and Qinghai provinces of northwest China, is historically important as one of the earliest metalworking cultures of China and as a center of intercultural communication between China and central Asia, detailed scholarship about the culture is still emerging. Qijia ceramics have been categorized by typology, but little has been done regarding methods of manufacture. This study used visual examination and digital X-radiography to investigate ceramic production, especially the use of a wheel. In addition, the ceramic paste, including natural inclusions and temper, was examined. While film radiography has often been used to study ceramics, digital radiography presented new capabilities as well as challenges. Experimentation through the making of test vessels and tiles at the Harvard Ceramics Program provided additional insights into Qijia ceramics’ manufacture and surface decoration techniques, often described as cord-impressed.
11
Pogodin, A. I., I. O. Shender, S. M. Bereznyuk, M. Y. Filep, O. P. Kokhan, L. M. Suslikov, and I. P. Studenyak. "Structure and Electrical Properties of Superionic Ceramics Based on Silver-Enriched (Cu0.25Ag0.75)7SiS5I Solid Solution." Ukrainian Journal of Physics 66, no. 6 (July 6, 2021): 489. http://dx.doi.org/10.15407/ujpe66.6.489.
Повний текст джерелаАнотація:
(Cu0.25Ag0.75)7SiS5I-based superionic ceramics were fabricated by using the micro- and nanopowders. The XRD technique and microstructural analysis are applied for the structural studies of powders and ceramic samples. The impedance measurements of ceramic samples are carried out in the frequency range from 10Hz to 2 × 106 Hz and temperature interval from 292 K to 383 K. The contributions of ionic and electronic conductivities into the total electrical conductivity are determined, and their temperature dependences are investigated. The influence of the size effect on ionic and electronic conductivities and their activation energies in (Cu0.25Ag0.75)7SiS5I-based ceramics is studied.
12
Alayad, Abdullah Saeed. "Ceramic Fracture in Bilayered All-ceramic Indirect Restoration: A Review of the Literature." Journal of Advanced Oral Research 10, no. 1 (April 4, 2019): 5–12. http://dx.doi.org/10.1177/2320206819831560.
Повний текст джерелаАнотація:
Background: High incidence of fracture of all-ceramic crowns may compromise the clinical outcome and is a source of hassle for both patients and dentist. Objective: The objective of the present review was to identify reasons for high ceramic fracture or chipping and to minimize these incidents in dental settings. Methods: The final search strategy was executed on Medline via OvidSP, PubMed, and Web of Knowledge. Studies meeting the following inclusion criteria were included in the current review. (1) Literature in English language only, (2) in vitro studies, (3) studies providing evidence on ceramic fracture, and (4) studies only related to indirect restoration and ceramics. Moreover, the exclusion criteria were based on (1) articles other than English, (2) studies reporting direct restoration, (3) any non–peer-reviewed gray literature, and (4) studies discussing fracture other than ceramic material. Results: From the initial search strategy, 101 studies were retrieved from different databases. A total of 3 studies were scrutinized through other resources. Following duplicate removal (n = 24), 80 studies were screened for the title and abstract. Moreover (n = 49) studies were shortlisted for full text and review. Following review and discussion in the final result, only 26 studies were included. Conclusions: Many improvements in the material, its fabrication process, and surface treatments can reduce the incidence of fracture within the material.
13
Ohnishi, Kazumasa, and Takashi Morohashi. "Studies on the Characteristics of Ceramic Fiber Reinforced Piezoelectric Ceramics." Japanese Journal of Applied Physics 28, S2 (January 1, 1989): 71. http://dx.doi.org/10.7567/jjaps.28s2.71.
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14
Pilathadka, Shriharsha, and Dagmar Vahalová. "Contemporary All-ceramic Systems – Part 2." Acta Medica (Hradec Kralove, Czech Republic) 50, no. 2 (2007): 105–7. http://dx.doi.org/10.14712/18059694.2017.64.
Повний текст джерелаАнотація:
Current all-ceramic materials offer a accepted level of fracture resistance, fit and aesthetics. High fracture resistance recommends it to be a material to support fixed partial denture (FPD) in a stress bearing area with clinical success. This part of the present literature review covers the success rate, selection criteria of all ceramic systems, cementation technique, finishing and polishing. In vitro and in vivo studies of new high strength ceramics were well documented. Data suggest that single crowns in the anterior and posterior region are more predictable than bridges. Well-studied longterm success rate for FPDs are very limited.
15
Lampropoulou, Paraskevi, and Dimitrios Papoulis. "Halloysite in Different Ceramic Products: A Review." Materials 14, no. 19 (September 23, 2021): 5501. http://dx.doi.org/10.3390/ma14195501.
Повний текст джерелаАнотація:
The increased demands of our rapidly developing way of life lead to the broadening of the ceramic market among other effects. Due to the advanced ceramic properties of halloysite and its abundance, combined with its good synergistic effect with other materials, it has been investigated for multifarious possible applications to produce traditional and advanced ceramics as well as ceramic composites. In this review, a substantial number of studies by several investigators into halloysite-based ceramics were are summarized. The possibilities and limitations of different halloysite-based ceramic materials for future applications are also discussed in this manuscript and new fields of research are proposed. The summarization of published results indicates a constant scientific interest in halloysite-based traditional ceramics and new potential uses in the future. Additionally, investigations on different novel ceramic composites with low cost halloysite nanotubes (HNTS) have rapidly increased, covering different scientific and technological areas. On the other hand, research into advanced ceramics (SiAlONS) has been pursued due to its highly cost effective technology treatments on a large scale.
16
Dulnev, A. "Applications of ceramics in composite protective structures." Transactions of the Krylov State Research Centre 2, no. 396 (May 21, 2021): 52–66. http://dx.doi.org/10.24937/2542-2324-2021-2-396-52-66.
Повний текст джерелаАнотація:
Object and purpose of research. The object of the study is ceramic-containing protective structures. The purpose of the study is to substantiate the feasibility and effectiveness of using ceramics as part of standard ship structures for protection against the effects of high-speed damaging elements. Materials and methods. Composites of the "ceramic + steel", "ceramic + fiberglass" type, made with the use of poly-crystalline ceramic materials based on boron carbide, nitride and silicon carbide, aluminum oxide and some other types, are considered. The study is based on an analytical approach, the results of ballistic tests of ceramic-containing composites and computational collapse simulation of ceramics in the composition of armor structures. Main results. The results of experimental studies demonstrating the level of efficiency of ceramic-containing structures are presented. The influence of the fragmentation features of various types of ceramics on the ballistic robustness of protective structures is shown. Structural and technological solutions aimed at increasing the survivability and ensuring the mounting of ceramic-containing structures on the ship are presented. Conclusion. The high efficiency of ceramics use in ship structures for protection against the impact of high-speed damaging elements is demonstrated. The use of ceramics in protective structures allows to get a significant increase in the ballistic robustness of structures while ensuring their ballistic survivability.
17
Porojan, Liliana, Florin Topală, and Sorin Porojan. "Numerical Simulation of the Occlusal Contacts in Roots Restored with Complete Ceramic Materials." Applied Mechanics and Materials 404 (September 2013): 152–57. http://dx.doi.org/10.4028/www.scientific.net/amm.404.152.
Повний текст джерелаАнотація:
Different high-strength, all-ceramic restorative systems are available for the restoration of endodontically treated roots. To date, many studies on fracture strength and fracture pattern have been conducted. Most of these studies focused on investigating stress distribution in the root dentin of abutment teeth restored with a post and core system. The objective of this study was to evaluate, by means of the finite element analysis, stresses induced in an endodontically treated maxillary central incisor that was restored with different all-ceramic systems during contacts with the antagonists. The first step of the study was to achieve 3D models in order to design and analyze teeth, all ceramic post and core systems and pressed ceramic crowns. Stress analysis was performed on the restored incisor during protrusion. As post and core materials pressed ceramics and zirconia were chosen, and for the full crown pressed ceramics was selected. Maximal equivalent stresses were recorded in the tooth structures and in the restorations for all contact areas. In the zirconia post and core systems stresses were higher than in the pressed ceramics post and core systems. The use of zirconia posts with a higher modulus of elasticity than pressed ceramics induce lower stresses in the dentin and higher in the crown than pressed ceramics posts.
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Moreira, Alana Mirely Félix, Cicera Denise Pinheiro Bezerra Borges, Larissa Araújo Lopes Barreto, Manassés Tercio Vieira Grangeiro, and Viviane Maria Gonçalves De Figueiredo. "Coroas cerâmicas bi-layers: Uma revisão de literatura sobre tipos de cerâmicas, processamento cerâmico e tensão residual." Journal of Dentistry & Public Health 11, no. 1 (June 5, 2020): 52. http://dx.doi.org/10.17267/2596-3368dentistry.v11i1.2880.
Повний текст джерелаАнотація:
INTRODUCTION: The usage of ceramic materials as a restoration strategy faces some problems, such as interferences between porcelain and zirconia, being the first one used as ceramic cover and the second one as infrastructure or coping. OBJECTIVE: review the literature on bi-layer ceramic crowns, through the types of ceramics, ceramic processing and residual stress.METHODOLOGY: Databases for this review were Bireme, Pubmed, Scielo and Virtual Libraries. Keywords were searched on Mesh. Inclusion criteria were Studies, Laboratorial and Clinical, Systematic Review and Meta-Analysis, papers and specific literature regarding the theme, in both English and Portuguese. Exclusion criteria were letter to the editor, clinical case and opinion piece, literatures that don’t face the theme and papers that analyze other odontological ceramics. Literature and papers were selected through summaries and abstracts. FINAL CONSIDERATIONS: Residual tension in bi-layers ceramics crowns with zirconia infrastructure and porcelain cover occur due to a lot of factors such as coefficient of thermal expansion, cooling speed, processing, and thickness of ceramic cover.
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Sevilla, Pablo, Carlos Lopez-Suarez, Jesús Pelaez, Celia Tobar, Veronica Rodriguez-Alonso, and María J. Suarez. "Influence of Low-Pressure Plasma on the Surface Properties of CAD-CAM Leucite-Reinforced Feldspar and Resin Matrix Ceramics." Applied Sciences 10, no. 24 (December 10, 2020): 8856. http://dx.doi.org/10.3390/app10248856.
Повний текст джерелаАнотація:
The introduction of new ceramic materials for dental restorations is currently a reality; however, little information is available on their surface treatment for the bonding process. Furthermore, surface treatment with plasma on ceramic materials has been recently introduced, although not many studies are available. The aim of this study was to evaluate the surface properties of a leucite-reinforced feldspar ceramic (LIC) and resin matrix ceramic (RMC) after low-pressure plasma treatment. From each material, 48 discs were prepared and subject to surface treatment. The LIC group was treated by hydrofluoric acid (HF) (LIC-HF), plasma with oxygen (LIC-O2), and plasma with argon (LIC-Ar). The RMC group was treated by sandblasting with alumina (RMC-SB), plasma with oxygen (RMC-O2), and plasma with argon (RMC-Ar). The groups whose surfaces were not subjected to treatment were considered as the control group. Surface wettability and roughness was analyzed. The results showed significant differences among the treatments for both ceramics regarding wettability and roughness. Plasma treatments increased the wettability and had a very low effect on the roughness. Plasma treatments achieved similar values for both surface properties in each ceramic group with no differences between both treatments. Plasma treatment seems to be a promising alternative for ceramic surface treatments since it increased the surface energy of the ceramics analyzed and hardly affects the roughness. Further studies are necessary to evaluate the effect of plasma treatment on the bond strength of ceramics.
20
Tan, Xiaoli, Hui He, and Jian-Ku Shang. "In situ Transmission Electron Microscopy Studies of Electric-field-induced Phenomena in Ferroelectrics." Journal of Materials Research 20, no. 7 (July 1, 2005): 1641–53. http://dx.doi.org/10.1557/jmr.2005.0213.
Повний текст джерелаАнотація:
High electric fields were delivered to specimens during imaging in the transmission electron microscopy (TEM) chamber to reveal details of electric field-induced phenomena in ferroelectric oxides. These include the polarization switching in nanometer-sized ferroelectric domains and the grain boundary cavitation in a commercial lead zirconate titanate (PZT) polycrystalline ceramic, the domain wall fracture in a Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal, and the transformation of incommensurate modulations in Pb0.99Nb0.02[(Zr1−xSnx)1−yTiy]0.98O3 (PZST100x/100y/2) polycrystalline ceramics. In the PZT ceramic, a cavitation process was uncovered for the electric field-induced intergranular fracture. In the ferroelectric single crystal, a preexisting crack was observed to deflect and to follow a 90° domain wall, indicating the presence of severe incompatible piezoelectric strains at thedomain wall. In the antiferroelectric PZST ceramics, the electric field-induced antiferroelectric-to-ferroelectric phase transformation was accompanied with the disappearance of incommensurate modulations.
21
Prasad, N. V., B. Ramaiah, V. Nathanial, and M. Chandra Sekhar. "Electrical Studies on PZT Ceramic." Advanced Materials Research 560-561 (August 2012): 816–19. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.816.
Повний текст джерелаАнотація:
Polycrystalline sample of PZT (52/48) was prepared by solid-state reaction method. X-ray analysis indicated the formation of single-phase. Electrical and impedance-spectroscopy plots were employed to analyze the electrical behavior of the sample, as a function of frequency, in the range of 0.01 Hz to 1 M Hz at different temperatures. Spectroscopic and complex plots indicated non-Debye dielectric relaxation. Detailed electrical studies revealed that the conduction is through hoping of electrons (extrinsic region) at lowers temperature and migration of oxygen vacancies at high temperature (intrinsic region). The results are explained using Euryod’s conduction model and confirmed with pyroelectric and ferroelectric data.
22
Galusek, D., Z. Lencés, P. Sajgalík, and Ralf Riedel. "Thermal analysis study of polymer-to-ceramic conversion of organosilicon precursors." Journal of Mining and Metallurgy, Section B: Metallurgy 44, no. 1 (2008): 35–38. http://dx.doi.org/10.2298/jmmb0801035g.
Повний текст джерелаАнотація:
The organosilicon precursors attract significant attention as substances, which upon heating in inert or reactive atmosphere convert directly to oxide or non-oxide ceramics, like nitrides, carbides, carbonitrides, boroncarbonitrides, oxycarbides, alons, etc. In characterisation, and in study of conversion of these polymers to ceramics thermal analysis plays an important role. The degree of cross-linking of the polymer vital for achievement of high ceramic yield is estimated with the use of thermal mechanical analysis (TMA). Decomposition of polymers and their conversion to ceramics is studied by the combination of differential thermal analysis (DTA), differential scanning calorimetry (DSC) thermogravimetry(TG), and mass spectrometry (MS). The use of these methods in study of the polymer-to-ceramic conversion is illustrated by case studies of a commercially available poly(allyl)carbosilane as the precursor of SiC, and a poly(hydridomethyl)silazane as the precursor of SiCN.
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Labunet, Anca, Andreea Kui, and Sorina Sava. "Laser Use in Creating Orthodontic Adhesion to Ceramic Surfaces." Applied Sciences 11, no. 6 (March 11, 2021): 2512. http://dx.doi.org/10.3390/app11062512.
Повний текст джерелаАнотація:
Orthodontists must sometimes bond attachments to ceramic crowns, by using one of the surface preparations available, such as sandblasting or acid etching with hydrofluoric acid. Research shows that different laser systems may also be used for this purpose. The aim of this review is to determine which laser type and modality of use is the most effective in increasing shear bond strength of brackets bonded to ceramic surfaces. Two independent researchers studied the current literature 1990–2018 and selected original articles focusing on in vitro research on laser use for ceramic surface preparation for bonding metallic or ceramic attachments. Twelve articles have met the criteria and have been thoroughly revised, focusing on 2 fractional, Nd:Yag, Er:Yag, femtosecond and Ti:Sapphire lasers. There is little difference shown by the current studies between ceramic types and information on orthodontic bonding to non-feldspathic ceramics is scarce. Femtosecond laser is a good alternative to classical surface preparation with hydrofluoric acid. Nd:Yag laser is more suitable for surface preparation of ceramics than different types of Er:Yag lasers. Difference in laser power may achieve different results, but the golden standard for lasers use has not been found. Laser usage does not obtain the same results as hydrofluoric acid and cannot, so far, eliminate its application.
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Godoy, Ana Lucia Exner, José Carlos Bressiani, and Ana Helena de Almeida Bressiani. "Influence of Addition of Polysiloxane on Sintering of Al2O3." Materials Science Forum 798-799 (June 2014): 696–702. http://dx.doi.org/10.4028/www.scientific.net/msf.798-799.696.
Повний текст джерелаАнотація:
The effects of adding polysiloxane (polymethylsilsesquioxane) on the sintering behavior, microstructure and hardness of alumina ceramics have been studied. The sintering kinetics of cold-pressed specimens was studied by dilatometry. Polymer sintering aid was used for alumina based ceramics sintered at 1650o C. The sintered materials were characterized using helium picnometry, x-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectrometry and Vickers indentation. The addition of polymethylsilsesquioxane yielded alumina/Si2Al4O4N4 composites. The sintering studies in nitrogen atmosphere (1650 °C/1h) revealed that the highest densities were obtained for specimens with 1wt% PMS. The materials prepared with ceramic polymer precursors had higher hardness than the standard specimen. The preparation of ceramic composites using small amounts of polymer precursors is suited for alumina based ceramics. The processing route being simple, it has the potential to enable the manufacture of complex shaped pieces.
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Intapong, Supansa, and Anirut Raksudjarit. "Treatment of Agricultural Wastewater Using Porous Ceramics Composite of Hydroxyapatite and Silica." Advanced Materials Research 622-623 (December 2012): 915–18. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.915.
Повний текст джерелаАнотація:
Porous ceramics filter was prepared by sintering of hydroxyapatite (HA) and silica composite nanopowder. Silica nanopowder of 50 wt% are incorporated into HA nanopowder. The mixing powders are uniaxially compact and then sintering at 900°C-1050°C in air. The characterization of the porous was carried out by scanning electron microscopy (SEM). Filtration studies using porous ceramic were performed for agricultural wastewater. The studies of the water filtration and flow through these porous showed that the sintered ceramic filter at all temperatures reduced the TDS, TS, conductivity, and arsenic (As) content. The water permeated through porous ceramic composites could be compared to drinking water quality.
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Reedy, Chandra L., Jenifer Anderson, and Terry J. Reedy. "Quantitative Porosity Studies of Archaeological Ceramics by Petrographic Image Analysis." MRS Proceedings 1656 (July 18, 2014): 337–53. http://dx.doi.org/10.1557/opl.2014.711.
Повний текст джерелаАнотація:
ABSTRACTPores in archaeological ceramics can form in a number of different ways, and reflect both deliberate choices and uncontrollable factors. Characterizing porosity by digital image analysis of thin sections holds a number of advantages as well as limitations. We present the results of experiments aimed at improving this method, focusing on high-resolution scans of entire thin sections. We examine the reproducibility of pore measurements by petrographic image analysis of ceramic thin sections using laboratory-prepared specimens of clay mixed with sand of known amount and size. We outline protocols for measuring Total Optical Porosity, using the Image-Pro Premier software package. We also briefly discuss use of pore size and pore shape (aspect ratio and roundness) in characterizing archaeological ceramics. While discerning reasons for observed amounts, sizes, and shapes of pores is an extremely complex problem, the quantitative analysis of ceramic porosity is one tool for characterizing a ware and comparing a product to others. The methods outlined here are applied to a case study comparing historic bricks from the Read House in New Castle, Delaware; the porosity studies indicate that different construction campaigns used bricks from different sources.
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Zeng, Qun, and Yong Heng Zhou. "Studies on Structural, Microwave Dielectric Properties, and Low-Temperature Sintering of 1.52Li2O-0.36Nb2O5-1.34TiO2 Ceramic." Key Engineering Materials 512-515 (June 2012): 1226–30. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.1226.
Повний текст джерелаАнотація:
The structure, microwave dielectric properties and low-temperature sintering of a new Li2O-Nb2O5-TiO2 system ceramic with the Li2O: Nb2O5: TiO2 mole ratio of 1.52: 0.36: 1.34 have been investigated in this study. The 1.52Li2O-0.36Nb2O5-1.34TiO2 (LNT) ceramic is composed of two phases, the “M-Phase” and Li2TiO3 solid solution (Li2TiO3ss) phase. This new microwave dielectric ceramic has low intrinsic sintering temperature ( ~ 1100 oC ) and good microwave dielectric properties of middle permittivity (εr ~38.6), high Q×f value up to 7712 GHz, and near zero τf value (~ 4.64 ppm/oC). In addition, the sintering temperature of the LNT ceramics could be lowered down effectively from 1100 oC to 900 oC by adding 1 wt.% B2O3. Good microwave dielectric properties of εr = 42.5, Q*f =6819 GHz and τf = 2.7 ppm/oC could be obtained at 900 oC, which indicate the ceramics would be promising candidates for low-temperature co-fired ceramics (LTCC) applications.
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D’Ercole, Giulia. "Seventy Years of Pottery Studies in the Archaeology of Mesolithic and Neolithic Sudan." African Archaeological Review 38, no. 2 (April 17, 2021): 345–72. http://dx.doi.org/10.1007/s10437-021-09432-y.
Повний текст джерелаАнотація:
AbstractThis review article examines seventy years of research and methodological approaches to the analysis of Mesolithic and Neolithic pottery in Sudan. It begins with the studies done by A. J. Arkell at the end of the 1940s, leading to the definition of the Khartoum Mesolithic and Khartoum Neolithic ceramic traditions. The article then discusses the application of the concepts of ware, fabric, decorative technique, and chaîne opératoire to the analysis of pottery and the use of new classification tools and archaeometric methodologies. The implication of the concepts of cultural encounter and the communicative role of material culture for ceramic studies and the insights that ceramics can provide for understanding the interrelationships between humans and the landscape are also discussed.
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Usman, Jamilu, Mohd Hafiz Dzarfan Othman, Ahmad Fauzi Ismail, Mukhlis A Rahman, Juhana Jaafar, and Tijjani Abdullahi. "Comparative study of Malaysian and Nigerian kaolin-based ceramic hollow fiber membranes for filtration application." Malaysian Journal of Fundamental and Applied Sciences 16, no. 2 (April 15, 2020): 182–85. http://dx.doi.org/10.11113/mjfas.v16n2.1484.
Повний текст джерелаАнотація:
Ceramic membrane has gained increasing interest in water filtration application due to its inherent characteristics. Low-cost clay materials are preferred to fabricate an efficient and cost-effective ceramic membrane. Among the ceramics, kaolin displays better mechanical, thermal, and chemical properties. However, natural properties of kaolin vary from different studies. Hence, cost-effective Nigeria (NK) and Malaysia (MK) kaolins were compared to study the fabrication of kaolin hollow fiber ceramic membrane for filtration application. The effects of kaolin loading concentration (34 and 37 wt. %) and sintering temperature (1200, 1350, 1400, and 1500 °C) on kaolin membrane fabrication were also studied. XRF studies indicated that the hydroxyl silica and alumina compositions were 56.76wt.% and 41.97wt% for NK and 55.21wt.% and 40.33wt% for MK. MK exhibited intense kaolinite peak with a broad range of particle size distribution. The mechanical stability of kaolin ceramic membrane increased with the increase of sintering temperature and kaolin loading concentration. Membrane morphology also varied with MK and NK. Interestingly, 34wt% kaolin at a sintered temperature of 1350 °C produced ceramic membrane with a high water flux. A similar trend was observed in both MK and NK, where the flux of 34wt% MK and NK are 565 and 460 L/m2h, respectively.
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Puli, Venkata Sreenivas, Shiva Adireddy, Manish Kothakonda, Ravinder Elupula, and Douglas B. Chrisey. "Low temperature sintered giant dielectric permittivity CaCu3Ti4O12 sol-gel synthesized nanoparticle capacitors." Journal of Advanced Dielectrics 07, no. 03 (June 2017): 1750017. http://dx.doi.org/10.1142/s2010135x17500175.
Повний текст джерелаАнотація:
This paper reports on synthesis of polycrystalline complex perovskite CaCu3Ti4O[Formula: see text] (as CCTO) ceramic powders prepared by a sol–gel auto combustion method at different sintering temperatures and sintering times, respectively. The effect of sintering time on the structure, morphology, dielectric and electrical properties of CCTO ceramics is investigated. Tuning the electrical properties via different sintering times is demonstrated for ceramic samples. X-ray diffraction (XRD) studies confirm perovskite-like structure at room temperature. Abnormal grain growth is observed for ceramic samples. Giant dielectric permittivity was realized for CCTO ceramics. High dielectric permittivity was attributed to the internal barrier layer capacitance (IBLC) model associated with the Maxwell–Wagner (MW) polarization mechanism.
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Yadava, Yogendra Prasad, and Ricardo Arthur Sanguinetti Ferreira. "Study of Sintering Behavior of Ba2AlSnO5.5 Ceramic Powder Compacts as Substrate for Temperature Sensing Devices." Materials Science Forum 591-593 (August 2008): 661–66. http://dx.doi.org/10.4028/www.scientific.net/msf.591-593.661.
Повний текст джерелаАнотація:
Ceramic components are frequently used as substrates for the production of temperature sensing devices in petroleum industries, in view of their high thermal and electrical resistance and inertness in hostile ambient conditions. Complex cubic perovskite oxide ceramics have a great advantage in terms of their varied physico-chemical characteristics with the substitution of structural elements in the respective formula units. In this context, we have produced Ba2AlSnO5.5 ceramics by solid state reaction process. Structural characteristics, studied by powder x-diffraction, reveal that Ba2AlSnO5.5 ceramic has an ordered complex cubic perovskite structure. Ba2AlSnO5;5 ceramics were sintered in the form of circular discs of 10 and 15 mm diameters and 2 mm thickness, in the temperature 1200 to 14000C by normal sintering process. The microstrutural characteristics were studied by scanning electron microscopy on both polished and fracture surfaces. The SEM micrographs show homogenous surface morphology and particle size distribution. Mechanical hardness of the sintered Ba2AlSnO5.5 ceramics were studied by Vicker´s hardness tests. The results of these studies have been presented and discussed in this work
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Francisco, Inês, Raquel Travassos, Catarina Nunes, Madalena Ribeiro, Filipa Marques, Flávia Pereira, Carlos Miguel Marto, et al. "What Is the Most Effective Technique for Bonding Brackets on Ceramic—A Systematic Review and Meta-Analysis." Bioengineering 9, no. 1 (January 3, 2022): 14. http://dx.doi.org/10.3390/bioengineering9010014.
Повний текст джерелаАнотація:
Background: There has been an increase in demand for orthodontic treatment within the adult population, who likely receive restorative treatments using ceramic structures. The current state of the art regarding the most effective method to achieve an appropriate bond strength of brackets on ceramic surfaces isn’t consensual. This systematic review aims to compare the available surface treatments to ceramics and determine the one that allows to obtain the best bond strength. Methods: This systematic review followed the PRISMA guidelines and the PICO methodology was used, with the question “What is the most effective technique for bonding brackets on ceramic crowns or veneers?”. The research was carried out in PubMed, Web of Science, Embase and Cochrane Library databases. In vitro and ex vivo studies were included. The methodological quality was evaluated using the guidelines for reporting of preclinical studies on dental materials by Faggion Jr. Results: A total of 655 articles searched in various databases were initially scrutinized. Sevety one articles were chosen for quality analysis. The risk of bias was considered medium to high in most studies. The use of hydrofluoric acid (HF), silane and laser afforded the overall best results. HF and HF plus laser achieved significantly highest bond strength scores in felsdphatic porcelain, while laser was the best treatment in lithium disilicate ceramics. Conclusions: The most effective technique for bonding brackets on ceramic is dependent on the type of ceramic.
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Seto, Tsz Ho, Anastasiia Grymak, Vidya Mudliar, and Joanne Jung Eun Choi. "Effect of Enamel Bleaching on the Bond Strength of Ceramic—A Systematic Review." Oral 2, no. 2 (June 15, 2022): 182–97. http://dx.doi.org/10.3390/oral2020018.
Повний текст джерелаАнотація:
The increase in aesthetic demands has increased the use of ceramic dental restorations in dentistry. Ceramic restorations are bonded to the tooth structure using adhesives. There is a lack of standard guidelines in terms of post-bleaching time intervals and bond strengths of ceramic restorations. Bleaching products have also been stated to affect the morphology of enamel. Therefore, the purpose of this systematic review is to evaluate the bond strength between ceramic and enamel and the changes in the surface roughness of enamel post teeth bleaching. An electronic search was performed in the databases PubMed, OVID MEDLINE, Scopus, and Web of Science with MESH terms: “adhesion OR bonding”, “ceramic OR ceramics OR dental porcelain”, “tooth bleaching OR teeth bleaching OR tooth whitening OR teeth whitening” and “enamel OR dental enamel OR enamels OR dental enamels”. The articles were screened, and the final selection of articles was obtained by using the inclusion and exclusion criteria. Of the 170 studies identified from the search, only 12 studies met the inclusion criteria and were selected for full-text review. A further search by hand was performed, and additional 48 studies were selected. From the 60 full-text studies, 18 studies met the inclusion criteria and were included for data extraction. The results were based on a descriptive analysis of the effect on bond strength of ceramic to enamel after a bleaching protocol and the changes in the surface roughness of enamel post bleaching protocol. In conclusion, bleaching protocols alter the surface roughness of enamel and, thus, the shear bond strength between ceramic and enamel. Bleaching treatments with a higher concentration of hydrogen peroxide reduce the bond strength between ceramic and enamel. Delaying bonding after bleaching for up to 7 days increases the bond strength between ceramic and enamel.
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Lukáš, Petr, Miroslav Vrána, Jan Šaroun, Vasyl Ryukhtin, Jef Vleugels, Guy Anné, Omer Van der Biest, and Michael M. Gasik. "Neutron Diffraction Studies of Functionally Graded Alumina/Zirconia Ceramics." Materials Science Forum 492-493 (August 2005): 201–6. http://dx.doi.org/10.4028/www.scientific.net/msf.492-493.201.
Повний текст джерелаАнотація:
New functionally graded Al2O3/Y-ZrO2 ceramics are developed as a new material for production of hip prosthesis, especially all-ceramic hip bearings. The used concept of graded ceramics is expected to provide better long-term performance based on improved mechanical properties and lower clinical risks. Mechanical properties are strongly dependent on the distribution of residual stresses resulting mainly from phase specific stresses after cooling from the sintering temperature. However, these stresses could be optimized by an appropriate selection of a concentration profile of constituent phases. The non-destructive neutron diffraction mapping of residual stresses has been used to investigate this problem experimentally. In addition, the smallangle neutron scattering technique was applied to study the porosity in the ceramics as function of the production parameters.
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J., Mu. "CERAMIC DISHES WITH HANDLES IN ALTAI: BRIEF OVERVIEW OF STUDIES, ANALYSIS OF SOURCES AND RESEARCH PERSPECTIVES." Preservation and study of the cultural heritage of the Altai Territory 27 (2021): 249–55. http://dx.doi.org/10.14258/2411-1503.2021.27.38.
Повний текст джерелаАнотація:
Ceramic dishes with handles appeared in Altai approximately in the 2nd half of the 6th century B.C. Their design is very peculiar and has no parallel in the cultures of the preceding period. This article investigates the results of the earlier studies and talks about the spread of ceramics with handles in China (in Gansu and Xinjiang) and its adjacent regions. The article also presents published opinions of scientists about the finds in the Pazyryk burials. Comparative analysis has allowed us to make the assumption that the presence of ceramics with handles in the Early Iron Age monuments in Central Asia is a reflection of migration during which people mastered the technologies of making such ceramic ware. Further comprehensive research of the existing data on these archaeological finds will provide a more detailed picture of the interaction between different ancient populations. Thus, this article describes the research lines which are ought to be carried out. Keywords: altai, Eastern Xinjiang, bronze age, early Iron Age, ceramics with handles, Pazyryk culture, migration, technology diffusion
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J., Mu. "CERAMIC DISHES WITH HANDLES IN ALTAI: BRIEF OVERVIEW OF STUDIES, ANALYSIS OF SOURCES AND RESEARCH PERSPECTIVES." Preservation and study of the cultural heritage of the Altai Territory 27 (2021): 249–55. http://dx.doi.org/10.14258/2411-1503.2021.27.38.
Повний текст джерелаАнотація:
Ceramic dishes with handles appeared in Altai approximately in the 2nd half of the 6th century B.C. Their design is very peculiar and has no parallel in the cultures of the preceding period. This article investigates the results of the earlier studies and talks about the spread of ceramics with handles in China (in Gansu and Xinjiang) and its adjacent regions. The article also presents published opinions of scientists about the finds in the Pazyryk burials. Comparative analysis has allowed us to make the assumption that the presence of ceramics with handles in the Early Iron Age monuments in Central Asia is a reflection of migration during which people mastered the technologies of making such ceramic ware. Further comprehensive research of the existing data on these archaeological finds will provide a more detailed picture of the interaction between different ancient populations. Thus, this article describes the research lines which are ought to be carried out. Keywords: altai, Eastern Xinjiang, bronze age, early Iron Age, ceramics with handles, Pazyryk culture, migration, technology diffusion
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Sutrisno, Sutrisno Sutrisno, and Dyah Rachmawati Lucitasari. "Determination of Optimal Process Parameters In The Process Of Making Ceramics To Maximize Flexural Strength Using the Taguchi Method (Case Study at the Kasongan Ceramics UKM Center, Bantul, DIY)." OPSI 14, no. 1 (June 24, 2021): 66. http://dx.doi.org/10.31315/opsi.v14i1.4498.
Повний текст джерелаАнотація:
Kasongan Ceramic UKM Center is an association of UKM which makes goods made from clay. Kasongan Ceramic UKM Center, located in Bantul Regency, DIY. The problem that is often experienced by Kasongan Ceramics Center is that products that are often cracked, warped, and easily brittle. The total production of Kasongan UKM Center from September 2019 to February 2020 was 32,256 units, with the number of defective products amounting to 3,873 or 12% of the total production. Based on the studies that have been done, it can be concluded that the defects of cracks, curling, and brittleness that occur are one of them caused by the less than optimal flexural strength of the ceramic products produced. To maximize the flexural strength of the ceramic products produced, the optimal ceramic manufacturing process parameters will be determined using the Taguchi method. To maximize the flexural strength in the process of making ceramics using the Taguchi method, it is necessary to do an experimental design. The first thing to do is to determine the controlled factors and levels in the ceramic manufacturing process that affect the flexural strength. After that determine a suitable orthogonal array and perform experiments based on the specified orthogonal array. The experimental results will be tested for its flexural strength in the laboratory. The resulting flexural strength data will be processed to determine the optimal ceramic manufacturing process parameters that maximize the bending strength of ceramics. Based on the data processing carried out, it is found that the optimal ceramic-making process parameters at the Kasongan Ceramics UKM Center that maximize flexural strength are the composition of 3 parts Godean clay, 3 parts Kasongan clay composition, 1 part sand composition, and burning using an open tub.
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Ryschenko, M. I., O. Yu Fedorenko, M. Yu Lisytkina, O. V. Shevtsov, K. V. Bіlohubkina, and N. M. Reheda. "Regularities of phase formation, structure and properties of chemically and thermally resistant ceramic materials." Scientific research on refractories and technical ceramics 118 (July 11, 2018): 119–31. http://dx.doi.org/10.35857/2663-3566.118.11.
Повний текст джерелаАнотація:
Based on the compositions of MgO—Al2O3—TiO2—SiO2 system, the chemically and thermally resistant ceramic was obtained at a firing temperature of 1250 °C by the directed synthesis of tialite and mullite phases. The influence of alternative raw materials of natural and technogenic origin on the operational properties and phase composition of porous and densely-sintered ceramic materials was studied. The using expediency of pyrophyllite containing waste of quartzite mining and ferrotitanium production wastes as the phase forming components of ceramic masses is established. The mechanism of structure- and phase formation of tialite and mullite-tialite ceramics was investigated. It was established that, stabilization of the tialite phase at a temperature of 1200—1250 oC occurs while maintaining the ratio of TiO2/Al2O3 oxides ~ 1.4 and the presence of 1.3 wt. % Fe2O3, as the mineralizing component included in the waste. The possibility of obtaining tialite containing ceramic materials at a lower firing temperature (1200 oC) due to the formation of a tialite solid solution (Mg0.3Al1.4Ti1.5O5) while maintaining the ratio of MgO : TiO2 oxides = 0.18 was proved. Technological principles of the production of chemically and thermally resistant ceramics both with the densely-sintered and with the porous structure, the total porosity of which is respectively 0.41 and 60 %, have been developed. The permeability of porous ceramic materials of mullitе-tialite composition was determined (water permeability coefficient P = 5.39∙10-5 cm2/s), as well as parameters of sorption processes (diffusion rate of Cr2O7-2 and MnO4- ions is 6.38∙10-6 and 1.06∙10-5 cm2/s respectively). This indicates the possibility of using the developed porous ceramics for the manufacture of industrial wastewater filters. Complex studies of the phase composition, structure and properties of the developed ceramic materials confirmed the promise of their use for the manufacture of parts of equipment operating in corrosive environments.
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Cucchi, Davide, Martin Gathen, Robert Streicher, and Dieter Wirtz. "Ceramic-on-Ceramic in Total Hip Replacement Revision." Zeitschrift für Orthopädie und Unfallchirurgie 156, no. 03 (February 27, 2018): 272–80. http://dx.doi.org/10.1055/s-0043-124767.
Повний текст джерелаАнотація:
Abstract Background The use of Ceramic-on-Ceramic (CoC) bearings in primary total hip arthroplasty (THA) is increasing and has been intensively analysed. This bearing plays a particularly relevant role in young, active patients and shows advantages over other bearings in biocompatibility, wear rate and lubrication properties. On the contrary, CoC bearings in revision THA are seldom used and scarcely analysed. The aim of this study is to systematically review the available literature on CoC bearings in revision THA. Methods A systematic research in the English literature was performed to identify all studies reporting results of THA revisions using ceramic-on-ceramic bearing. The initial search strategy revealed 555 articles for consideration. On the basis of eligibility criteria, 26 studies were included in this review. Results Twenty-six studies, accounting for 1846 procedures, were eligible and included in the review. No studies of Level I were identified. Eighteen studies reported on revisions of CoC implants for various reasons, performed either with CoC or different bearings. In 111 patients a CoC bearing was used for the revision. Six studies consistently reported outcome measures for CoC bearing THA revisions, so that a quantitative synthesis of the data was possible. The range of follow-up across the six studies varied between 2.1 and 19 years, with a cumulative avearage follow-up of 9.3 years. A good functional result was documented, with a cumulative weighted mean for postoperative Harris Hip Score (HHS) of 87 points. The rate of dislocation in this group was 3.45% and the risk of fracture of an alumina ceramic head was 0.35% (1 study). Squeaking was reported as complication of CoC bearing THA revisions in three studies, with a calculated incidence of 0.52%. Conclusion Modern CoC bearings show advantages in preclinical and retrospective studies over other bearings also in revision cases and are therefore to be considered a promising alternative for this kind of operation. Reasonable indications for CoC bearing in revision THA are revisions for aseptic loosening or recurrent dislocation in young patients, fractures of ceramic components, large acetabular defects or in patients that are allergic to bone cement components. Nevertheless, prospectively designed or randomized studies are lacking and needed to confirm CoC as optimal solution for revision THA cases.
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KALEMTAS, AYSE. "Low - Temperature Sintering of Porous Ceramics via Sodium Borate Addition." Material Science Research India 16, no. 1 (January 25, 2019): 48–55. http://dx.doi.org/10.13005/msri/160107.
Повний текст джерелаАнотація:
In the current study, sodium borate-bonded highly open porous ceramics successfully produced by starch consolidation technique. Open porous ceramic production was carried out by using an economical grade a-Si3N4, corn starch, CC31 commercial-grade kaolin, and borax decahydrate (Na2B4O7.10H2O). Borax decahydrate was used as a sintering aid in the system and total ceramic (a-Si3N4 + CC31): borax decahydrate ratio was kept constant at 5:1. Sintering studies of the shaped samples carried out in an air atmosphere at a relatively low sintering temperature, 1100°C, for one hour. Scanning electron microscopy investigations of the porous ceramic samples revealed that due to the high amount of borax based sintering additive a significant amount of liquid phase formed during the sintering process of the designed ceramics. Highly open porous(~66-74%) and lightweight(~0.64-0.83 g/cm3) ceramics were produced via starch consolidation technique and low-temperature sintering at atmospheric conditions.
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Camilo, Claudia C., C. A. Fortulan, N. A. Parizotto, and B. de M. Purquerio. "Porous Alumina Scaffolds with Bioactive Coating: Implants in the Rat Tibia and In Vitro Studies." Key Engineering Materials 396-398 (October 2008): 699–702. http://dx.doi.org/10.4028/www.scientific.net/kem.396-398.699.
Повний текст джерелаАнотація:
Ceramic scaffolds, mechanically qualified, highly porous, non biodegradable and with bioactive coating have been manufactured. The aim of this study was evaluated mechanical and in vivo responses of the porous alumina scaffolds with bioactive coating. The bioactive coating was performed under vacuum with bio-glass (45S5®)) and hydroxyapatite (HAp). Alumina ceramics (Al2O3) are used for bone implants in function of the biocompatibility and the high mechanical reliability of this material. Unfavourably alumina is a bioinert material and bone ingrowths are hard to occur and any implant anchorage becomes difficult. To improve this, ceramic scaffold samples were made with porosity concentration around 75vol% and with average pores diameters around 190.0µm. They were mechanically characterized through macro and micro structural analyses and mechanical tests and biologically through cell culture tests with fibroblastic VERO cell line for cytotoxicity and animal experiments on tibiae rats – Rattus norvegiicus albinos – aiming histological and line scan analysis in order to check the scaffold-bone cellular interaction. Current results seem to suggest the promising properties of the bioactive coated alumina ceramic scaffolds tested. The concentration of 75vol% alumina showed to be the great alternative for an economical solution for porous alumina ceramic scaffolds related to the mechanical properties and bone integration.
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Ramanathan, S., and M. F. Modest. "High‐speed photographic studies of laser drilling of ceramics and ceramic composites." Journal of Laser Applications 7, no. 2 (June 1995): 75–82. http://dx.doi.org/10.2351/1.4745376.
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Goryainova, Kristina E., Egor S. Morokov, Marina V. Retinskaja, Fedor S. Rusanov, Samvel V. Apresyan, and Igor Yu Lebedenko. "The Micromorphological Research of the Internal Structure of Chairside CAD/CAM Materials by the Method of Scanning Impulse Acoustic Microscopy (SIAM)." Open Dentistry Journal 12, no. 1 (January 31, 2018): 125–32. http://dx.doi.org/10.2174/1874210601812010125.
Повний текст джерелаАнотація:
Aim:The aim of the present work was to compare the elastic properties and internal structure of 4 different CAD/CAM chairside materials, by the method of Scanning Impulse Acoustic Microscopy (SIAM).Methods:Four chairside CAD/CAM materials with different structures from hybrid ceramic (VITA Enamic, VITA Zahnfabrik), feldspatic ceramic (VITABlocs Mark II, VITA Zahnfabrik), leucite glass-ceramic (IPS Empress CAD, Ivoclar Vivadent) and PMMA (Telio CAD, Ivoclar Vivadent) were examined by Scanning Impulse Acoustic Microscope (SIAM).Results:The results of micromorphological research of CAD/CAM chairside materials using SIAM method showed differences between the internal structures of these materials. The internal structure of feldspatic and glass-ceramic samples revealed the presence of pores with different sizes, from 10 to 100 microns; the structure of polymer materials rendered some isolated defects, while in the structure of hybrid material, defects were not found.Conclusion:Based on the results obtained from the present study, in cases of chairside production of dental crowns, it would be advisable to give preference to the blocks of hybrid ceramics. Such ceramics devoid of quite large porosity, glazing for CAD/CAM crowns made from leucite glass-ceramic and feldspatic ceramic may be an option. For these purposes, commercially available special muffle furnace for clinical and laboratory individualization and glazing of ceramic prostheses were provided. Further studies are needed to confirm the evidence emerging from the present research.
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Kennett, Douglas J., Barbara Voorhies, and Josue Gomez. "Reconsidering the Age and Typological Character of “Pox Pottery” from Guerrero, Mexico." Latin American Antiquity 32, no. 3 (May 3, 2021): 503–16. http://dx.doi.org/10.1017/laq.2021.14.
Повний текст джерелаАнотація:
We revisit the age and typological character of “Pox Pottery” that was reported in the 1960s by Charles Brush who considered it to be uniquely early (~2440 BC). Investigating the same two sites in coastal Guerrero where Brush excavated, we recovered Early Formative ceramics, some with the “pox” attribute. Here, we report potsherd frequencies for these deposits at both sites according to regional ceramic typologies, as well as AMS 14C dates used to establish a Bayesian stratigraphic chronology for each site to better constrain the age of these Early Formative period deposits. We argue that “Pox Pottery” is not a ceramic type per se and that the “pox” attribute occurs in multiple Early Formative period ceramic types. The earliest pottery is similar to other Red-on-Buff ceramic traditions from the Central Mexican Highlands and west of the Isthmus of Tehuantepec. Our chronological work demonstrates that these ceramics date between 1820 and 1400 cal BC, consistent with other recent studies indicating an early age of Red-on-Buff ceramics and suggesting shared cultural traditions distinct from the contemporary Locona interaction sphere that emerged in parallel.
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Sugiyama, Toyohiko. "Construction of a Glaze Database." Key Engineering Materials 608 (April 2014): 37–40. http://dx.doi.org/10.4028/www.scientific.net/kem.608.37.
Повний текст джерелаАнотація:
In the research of ceramic glazes, the process of preparing the glaze test pieces and improving the recipe is repeated. Our institute, AIST Japan, has more than 300,000 glaze test pieces from over 80 years of ceramic studies. These pieces are the physical evidence of the processes and the results of glaze test experiments. As such, they provide valuable information for glaze and ceramic research. The Ceramic Color Database has been constructed to make this fundamentally important information widely accessible in support of R&D in the ceramics industry. The database includes: glaze name, firing temperature, firing atmosphere, coloring, chemical composition, recipe, physical state, and other information, as well as images of the glaze pieces. The database has been used in recent ceramics research, and its effectiveness has been verified. It was also recognized that the vast amount of data provided by the database is useful in the material development and basic research of fields other than ceramics. The database has been improved based on such usage status. In this paper, the structure and usage of the database are described and the future development of the database is discussed.
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Nutt, S. R., and P. Lipetzky. "Creep Damage Mechanisms in Ceramic Composites." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 922–23. http://dx.doi.org/10.1017/s0424820100088920.
Повний текст джерелаАнотація:
Whisker-reinforced ceramics show improvements in a variety of mechanical properties, and because of the inherent thermal and chemical stability of ceramics, it is natural to consider issues related to mechanical behavior at high temperatures. Implementation of ceramic materials in high-temperature structural applications is often limited by creep, and recent studies on Al2O3-SiCw have shown that creep resistance of ceramics can be enhanced by whisker reinforcement. These studies demonstrated that creep response is strongly affected by the presence of the reinforcing phase and the properties of the whisker-matrix interface, in addition, oxidation reactions that occurred during creep degraded interface properties, facilitated microstructural damage, and accelerated creep. The objective of the present study was to determine the effects of test ambients on creep damage mechanisms in Al2O3-SiCw composites and to correlate these observations with compressive creep response under different stress-temperature conditions.
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Lynn, Ciarán J., Ravindra K. Dhir, and Gurmel S. Ghataora. "Sewage sludge ash characteristics and potential for use in bricks, tiles and glass ceramics." Water Science and Technology 74, no. 1 (March 24, 2016): 17–29. http://dx.doi.org/10.2166/wst.2016.040.
Повний текст джерелаАнотація:
The characteristics of sewage sludge ash (SSA) and its use in ceramic applications pertaining to bricks, tiles and glass ceramics have been assessed using the globally published literature in the English medium. It is shown that SSA possesses similar chemical characteristics to established ceramic materials and under heat treatment achieves the targeted densification, strength increases and absorption reductions. In brick and tile applications, technical requirements relating to strength, absorption and durability are achievable, with merely manageable performance reductions with SSA as a partial clay replacement. Fluxing properties of SSA facilitate lower firing temperatures during ceramics production, although reductions in mix plasticity leads to higher forming water requirements. SSA glass ceramics attained strengths in excess of natural materials such as granite and marble and displayed strong durability properties. The thermal treatment and nature of ceramic products also effectively restricted heavy metal leaching to low levels. Case studies, predominantly in bricks applications, reinforce confidence in the material with suitable technical performances achieved in practical conditions.
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Sokovnin, S. Yu, and M. E. Balezin. "Optical studies of metal ceramic cathode." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1010 (September 2021): 165562. http://dx.doi.org/10.1016/j.nima.2021.165562.
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Ixer, Rob A. "Ceramic studies: examining the full spectrum." Antiquity 92, no. 362 (April 2018): 531–33. http://dx.doi.org/10.15184/aqy.2018.24.
Повний текст джерелаАнотація:
These three books range from the clinical (Hunt) to the folksy (Woodward and Hill), and might be seen as a progression. One travelling from the Hunt-edited encyclopaedia with its emphasis on new and exotic scientific analytical techniques, rigorous theoretical approaches and data analysis, through the Integrative approaches book using techniques and ideas that have proved effective for decades (this book is firmly within the mainstream of recent excellent pot books that have a very strong US contribution, as exemplified by Quinn 2009), to the English, and almost quaint, re-issue of Woodward and Hill outlining post-processualist concerns and quite devoid of any black box ‘gee-whiz’. Their combined 1200 pages, heavily featuring petrography, often alongside geochemistry, show that these sorts of ceramic studies, although often regarded as comatose-inducing, are in favour again.
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Chadwick, A. V., F. Colombo, G. E. Rush, R. A. Davies, and M. S. Islam. "EXAFS studies of ceramic proton conductors." Radiation Effects and Defects in Solids 155, no. 1-4 (November 2001): 421–24. http://dx.doi.org/10.1080/10420150108214148.
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