The use of a waste from mineral processing, a spodumene-bearing rock, was investigated as a flux for bone china composition, partially replacing feldspar. The effect of lithium oxide in bone china ...body was favorable for reducing firing temperature. The presence of LI sub(2)O reacting with other oxides and silicates formed a liquid phase of lower viscosity, which was favorable for densification through viscous flow sintering, and to a higher mechanical strength. It was obtained a large plateau for firing, without deformation on firing (pyroplastic deformation) of parts; which is not an easy task to be achieved in bone china processing. Rheological and casting properties were also investigated. Microstructures of the fired bodies were discussed. They correlated well with the final properties of the parts.
Abstract
Bone china is known for its technical and aesthetical quality with distinguishable whiteness, brightness and high mechanical strength. In this work, the use of waste glass was investigated ...in a bone china composition. This makes the production of this porcelain even more interesting from the environmental point of view, since most of its raw materials are from recyclable sources. Potash feldspar was partially replaced by waste glass, and the technical and slip rheological properties, phase development and microstructure after firing of the ceramic bodies were evaluated. The results revealed that waste glass provides a reduction in firing temperature and large plateau for firing while maintaining the quality of the final porcelain, including thermal expansion and mechanical strength.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
► In this paper we propose a fast and robust system for quality assessment of electric resistance welds. ► The system implements a technique which assesses the quality of the welds based on ...statistical analysis. ► The signal processing tasks carried out by the system are real-time compliant in order to meet the deadline imposed by other systems.
Assessing the quality of a weld in the steelmaking industry is a complex task. The level of complexity increases when the assessment is based on non-destructive tests. Skilled technicians are often required to make a decision based on automatic assessments of welds. Technicians consider the results of the automatic assessments and use their expert knowledge in order to make a final decision about the quality of the weld. In this paper we propose a decision support system to assess the quality of resistance seam welds of steel strips based on statistical analysis of both the mechanical and electrical variables involved in the welding process to be assessed as well as previously recorded historical data of similar welds. The proposed system is designed following component model based software architecture. The system consists of a set of orthogonal modules: welding variable measurement, welding variable processing and welding quality assessment, communicated by means of dedicated interfaces. The proposed system has been installed in three steel manufacturing lines. With the reduction in the time spent by technicians to make a decision about each weld, the productivity of the manufacturing line has greatly improved. Furthermore, production costs have been reduced since the number of defective welds assessed as non-defective was reduced, and thus the failures in the manufacturing lines due to weld breakages. The experimental results after two years of use in a steel strip galvanizing line are shown.
According to estimates by the World Health Organization, about 285 million people suffer from some kind of visual disability, of whom 39 million are blind, resulting in 0.7% of the world population. ...Computer vision techniques and image analysis can help improve visually-impaired people. In this project, a system that allows for facial recognition and detection of spoofing adapted to the needs of disabled people is proposed, implemented and validated. The architecture has been carefully selected and subsequently implemented following an innovative facial normalization algorithm in order to increase both the recognition rate of facial identification and spoofing detection. The information provided to the user is composed by the name of the person identified and whether it is real or fake image (photograph). This information is provided by means of a text-to-speech tool. This architecture can be integrated into video door-phone installations (videointercom installations), devices with reduced computing capabilities or the users´ mobile phones. The architecture has been validated in a real environment with both real users and printed images achieving very good results.
Atmospheric pollution is one of the biggest problems and concerns in modern society, especially in industrial and highly populated areas. Poor air quality can have adverse impact on human health and ...ecosystems. For this reason, air quality forecasting becomes increasingly important, especially for governments and administrations, which use these predictions to enhance the design of mitigation actions in order to reduce air pollution in urban areas. In this framework, process of pollutant dispersion simulation is the best way to predict the most affected areas by industrial and other kinds of emissions. To carry out these simulations, there is a great number of computational tools currently available. However, not all of them have the same functionalities, nor can they be applied to the same case studies, so it is necessary to establish the advantages and disadvantages of each one of them in order to choose the most suitable tool in each case. Therefore, the objective of this paper is to identify the main available simulation tools and to make a comparative review between them in order to define advantages and disadvantages.
Air pollution is one of the major environmental problems, especially in industrial and highly populated areas. Remote sensing image is a rich source of information with many uses. This paper is ...focused on estimation of air pollutants using Landsat-5 TM and Landsat-8 OLI satellite images. Particulate Matter with particle size less than 10 microns (PM10) is estimated for the study area of Principado de Asturias (Spain). When a satellite records the radiance of the surface received at sensor, does not represent the true radiance of the surface. A noise caused by Aerosol and Particulate Matters attenuate that radiance. In many applications of remote sensing, that noise called path radiance is removed during pre-processing. Instead, path radiance was used to estimate the PM10 concentration in the air. A relationship between the path radiance and PM10 measurements from ground stations has been established using Random Forest (RF) algorithm and a PM10 map was generated for the study area. The results show that PM10 estimation through satellite image is an efficient technique and it is suitable for local and regional studies.
A crescente preocupação ambiental trouxe grande interesse na reutilização e reciclagem de materiais. Dentro desse contexto, está o propósito do presente trabalho de estudar a utilização de um resíduo ...de embalagens de vidro em porcelana de ossos. Especificamente, foi analisado o comportamento reológico de formulações de porcelana de ossos, nas quais o fundente feldspato foi parcialmente substituído por vidro reciclado. Avaliou-se a reologia em relação ao comportamento da viscosidade e da tensão de cisalhamento em função da taxa de cisalhamento, e da viscosidade em função da concentração de dispersante, considerando-se a especificidade de cada matéria-prima. As peças coladas foram avaliadas em relação à facilidade de desmoldagem, tempo de formação de parede e qualidade visual do colado. Obteve-se uma barbotina com o vidro com estabilidade e comportamento reológico próximo da de feldspato.
The growing environmental concern brought great interest in recycling of materials. This paper shows the use of waste glass in bone china, and the analysis of the rheological behavior of bone china compositions, in which the feldspar flux was partially replaced by recycled glass. We evaluated slip viscosity, shear stress, shear rate, and viscosity in function of dispersant addition, considering the specificity of each raw material. The casting pieces were analyzed for ease of demoulding, wall-forming time and visual quality of the parts. The slip with glass showed stability and rheological behavior similar to the feldspar slip.
O uso dos ossos bovinos, subproduto da indústria de gado de corte, na manufatura de produtos cerâmicos pode ser uma alternativa para a valorização desse material no mercado. A produção de um tipo ...especial de porcelana conhecida como "bone china" emprega cerca de 50% em peso de ossos calcinados, valorizando a utilização de matéria-prima reciclada na manufatura de louças de qualidade refinada. No caso de porcelanas processadas por colagem de barbotina, o tratamento realizado sobre os ossos, para a remoção da matéria orgânica, afeta diretamente as propriedades reológicas das suspensões contendo esta matéria-prima. O presente estudo avalia a influência das condições de calcinação sobre as características físico-químicas dos ossos para a aplicação em porcelanas processadas por colagem de barbotina. Foram analisadas as propriedades do pó de ossos por meio de espectrocopia por infravermelho, difração de raios X, granulometria a laser, área superficial específica e microscopia eletrônica de varredura. O comportamento reológico dos ossos em suspensão é avaliado em função da concentração de sólidos e do tipo e quantidade de dispersante utilizado em solução. Os resultados obtidos indicam que a temperatura de calcinação afeta as propriedades do pó, alterando sua reologia e a quantidade de dispersante necessária à estabilização das suspensões.
The use of bovine bone, a byproduct of the cow meat industry, in the manufacture of ceramic products can be an alternative for a higher value of such material on the market. The production of a special type of porcelain known as "bone china" employs about 50% by weight of calcined bones, emphasizing the use of recycled raw material in the manufacture of quality refined porcelain. In the case of porcelain processed by slip casting, the treatment performed on bone, to remove the organic matter directly affects the rheological properties of the slips containing this raw material. The present study evaluates the influence of calcination conditions on the physicochemical characteristics of the bones for use in porcelain processed by slip casting. We analyzed the properties of the bone powder by means of infrared spectroscopy, X-ray diffraction, laser particle size, specific surface area and scanning electron microscopy. The rheological behavior of the bone slip is evaluated as a function of solids concentration and the type and amount of dispersant used in solution. The results indicate that the calcination temperature affects the properties of the powder, changing its rheology and amount of dispersant required for stabilizing suspensions.
On the absorption of ozone by water Carus, L.
The London, Edinburgh and Dublin philosophical magazine and journal of science,
18/1/1/, Letnik:
44, Številka:
296
Journal Article
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007.
Title from title screen (site viewed Nov. 9, 2007). PDF text: 131 p. : facsims. ; 11 Mb. UMI publication number: AAT 3263484. Includes ...bibliographical references. Also available in microfilm and microfiche formats.
PDF
