Research and Development of Multifunctional Porous Materials on the Basis of Clay and Glass Waste

2021 ◽  
Author(s):  
◽  
Andrejs Šiškins

The Ph. D. Thesis is devoted to the obtaining of porous ceramics from Latvian clay and household waste ‒ glass cullet. Using modern technological approaches porous and highly porous clay-glass ceramics were obtained, their properties and practical application possibilities were studied. The Doctoral Thesis consists of an introduction, literature review, methodical part, evaluation of the results of the experimental part, conclusions, and bibliography.

2019 ◽  
Vol 770 (5) ◽  
pp. 51-56
Author(s):  
Yu.G. BORISENKO ◽  
◽  
R.M. AZAN ◽  
D.P. SHVACHEV ◽  
D.A. VOROBIEV ◽  
...  

2020 ◽  
Vol 2 (1) ◽  
pp. 4-11
Author(s):  
Marcia Borba ◽  
Paula Benetti ◽  
Giordana P. Furini ◽  
Kátia R. Weber ◽  
Tábata M. da Silva

Background: The use of zirconia-based ceramics to produce monolithic restorations has increased due to improvements in the optical properties of the materials. Traditionally, zirconiabased ceramics were veneered with porcelain or glass-ceramic and were not directly exposed to the oral environment. Therefore, there are several doubts regarding the wear of the monolithic zirconia restoration and their antagonists. Additionally, different surface treatments are recommended to promote a smooth surface, including glaze and several polishing protocols. To support the correct clinical application, it is important to understand the advantages and limitations of each surface treatment. Objective: The aim of this short literature review is to investigate the factors that may affect the wear of monolithic zirconia restorations in service and their antagonists. Methods: Pubmed/Medline database was accessed to review the literature from a 10-year period using the keywords: zirconia, monolithic, prosthesis, wear. Both clinical and in vitro studies were included in the review. Results: Studies investigated the effect of several surface treatments, including grinding with diamond- burs, polishing and glazing, on the surface roughness, phase transformation and wear capacity of monolithic zirconia. The wear behavior of monolithic zirconia was frequently compared to the wear behavior of other ceramics, such as feldspathic porcelain, lithium disilicate-based glassceramic and leucite-reinforced glass-ceramic. Human tooth, ceramics and resin composites were used as antagonist in the investigations. Only short-term clinical studies are available (up to 2 years). Conclusion: Literature findings suggest that zirconia monolithic restorations are wear resistant and unlikely to cause excessive wear to the antagonist, especially when compared to feldspathic porcelain and glass-ceramics. Monolithic zirconia should be polished rather than glazed. Yet, none of the polishing systems studied was able to completely restore the initial surface conditions of zirconia after being adjusted with burs. More clinical evidence of the antagonist tooth wear potential of monolithic zirconia is needed.


2020 ◽  
Vol 67 (1) ◽  
pp. 148-155
Author(s):  
Anatoliy V. Fedotov ◽  
Viktor S. Grigoriev ◽  
Dmitriy A. Kovalev ◽  
Andrey A. Kovalev

To speed up the wastewater treatment under aerobic conditions and to optimize the processes of anaerobic wastewater treatment in digesters, immobilization technologies of microorganisms and enzymes on solid carriers are used. Ceramic carriers based on aluminosilicates and alumina are one of the promising inorganic biomass carriers. (Research purpose) To study the structure of porous ceramic biomass carriers for anaerobic processing of organic waste and evaluate the prospects for their use. (Materials and methods) The substrate for anaerobic digestion was a mixture of sediments of the primary and secondary sewage sumps of the Lyubertsy treatment facilities. K-65 cattle feed was used to ensure the constancy of the composition of organic substances in substrates as a cosubstrate. The authors used the method of low-temperature nitrogen adsorption of Bruner-Emmett-Teller to study the pore structure and specific surface of solid carriers on a specific surface analyzer Quntachrome Autosorb-1. (Results and discussion) The main characteristics (specific surface, volume of micro- and mesopores, predominant pore radius, water absorption and others) of chamotte foam lightweight and highly porous corundum ceramics were determined. It was revealed that ceramic materials with a developed surface and electrically conductive material provided an increase in biogas yield by 3.8-3.9 percent with an increase in methane content by an average of 5 percent. (Conclusions) The results of anaerobic digestion showed a positive effect of both a conductive carrier and highly porous ceramic materials on the process of anaerobic bioconversion of organic waste into biogas. It is advisable to expand experimental studies on the use of a conductive carrier with a developed surface based on highly porous ceramics.


Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 74
Author(s):  
Alejandro Sobron ◽  
David Lundström ◽  
Petter Krus

Testing of untethered subscale models, often referred to as subscale flight testing, has traditionally had a relatively minor, yet relevant use in aeronautical research and development. As recent advances in electronics, rapid prototyping and unmanned-vehicle technologies expand its capabilities and lower its cost, this experimental method is seeing growing interest across academia and the industry. However, subscale models cannot meet all similarity conditions required for simulating full-scale flight. This leads to a variety of approaches to scaling and to other alternative applications. Through a literature review and analysis of different scaling strategies, this study presents an overall picture of how subscale flight testing has been used in recent years and synthesises its main issues and practical limitations. Results show that, while the estimation of full-scale characteristics is still an interesting application within certain flight conditions, subscale models are progressively taking a broader role as low-cost technology-testing platforms with relaxed similarity constraints. Different approaches to tackle the identified practical challenges, implemented both by the authors and by other organisations, are discussed and evaluated through flight experiments.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2798
Author(s):  
Konstanty M. Gawrylczyk ◽  
Szymon Banaszak

The paper provides a review of the modelling techniques used to simulate the frequency response of transformer windings. The aim of the research and development of modelling methods was to analyze the influence of deformations and faults in the windings on the changes in the frequency response. All described methods are given with examples of the modelling results performed by the authors of this paper and from literature sources. The research is prefaced with a thorough literature review. There are described models based on lumped parameters with input data coming from direct calculations based on the winding geometry and obtained from FEM modelling software and models considering the wave phenomena in the windings. The analysis was also performed for practical problems in winding modelling: the influence of windings other than the modelled one and the influence of parallel wires in a winding.


2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.


2015 ◽  
Vol 63 (1) ◽  
pp. 305-314 ◽  
Author(s):  
S. Skoczypiec

Abstract One of the research and development trends in nowadays manufacturing technology is integration of different manufacturing techniques into single machine tool. In the first part of the paper possibilities, goals, reasons and advantages of thermal and electrochemical interaction have been characterized. As literature review indicates such a connection can be realized as sequential or hybrid machining. The second part of the paper focuses on detailed analysis of laser assisted electrochemical process. For this purpose, the mathematical model of workpiece heating has been developed. Based on obtained results and literature review possibilities of technical realization and potential application have been discussed.


2021 ◽  
Author(s):  
◽  
Nick van Dijk

<p>Multiphonics is the production of more than one tone at a time from an instrument that would normally play a single line. The aim of this work is to identify and explore the elements of multiphonics as played by jazz brass players and to examine the production and development of multiphonics with particular reference to Albert Mangelsdorff’s mature technique. The research procedure includes a literature review, transcription and analysis of relevant music, and reflection on personal practice. The findings and discussion are used to draw conclusions in order to derive applicable testable techniques. The research points to where the accretion and extension of Mangelsdorff’s playing style may lead, and demonstrates the acquisition of discovered multiphonic techniques by the performance of transcriptions and new or extended musical applications of multiphonics in two recorded assessed recitals. The body of the paper gives brief biographical information on the main practitioners, with specific focus on how each of them acquired particular technical elements. Reference is made to prior research and specific recordings and players are mentioned in regard to their innovations and stylistic techniques. Elements were discovered and explored in the researcher’s own practice over the previous decade and specifically the duration of the masters study from February 2008 – June 2009, and the effects of various approaches and exercises are discussed. This discussion includes the areas of mental and physical preparation, limitations and parameters of the physical playing, and the method used for developing multiphonic technique. The summary identifies the main findings and makes specific reference to how they might relate to practice. It suggests areas where further research can be developed to support the acquisition and practical application of multiphonic technique and extended techniques in brass performance. The work is presented as a paper and accompanying DVD that demonstrates findings as played by the researcher in live recitals.</p>


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