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.
► 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.
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.
Para un creciente número de agentes interesados, el turismo en la alta montaña supone un conflictivo dilema entre el disfrute recreativo de ésta, su explotación económica y la conservación de las ...frágiles áreas donde aquel inevitablemente tiene su destino. La cuestión cobra especial relevancia en el sistema montañosos pirenaico. En este trabajo se realiza una revisión del impacto de los Centros Turísticos Recreativos de Alta Montaña (CTRAM) en el medio y del concepto de sostenibilidad. A continuación, se procede a describir un modelo para mejorarla, que muestra la naturaleza de las relaciones entre los distintos grupos de interés y sus diferentes grados de poder negociador a la hora de decidir la creación de valor sostenible. En este marco, la participación a través de la Economía Social, desempeña una función significativa debido a su trayectoria para impulsar y potenciar la implicación de diversos agentes y de la población local en el proceso.
High mountain tourism poses a dilemma for an increasing number of those concerned due to the conflict between recreational enjoyment of the area, its economic exploitation and conservation of the fragile areas that will inevitably be affected by it. This is a particularly important issue in the Pyrenees mountains. This paper looks at the impact on the environment of High Mountain Recreational Tourism Centres (CTRAM) and the concept of sustainability. We propose ways to improve the situation, describing the nature of the relationships between the different stakeholders and their differing degrees of bargaining power when taking decisions regarding the creation of sustainable value. Within this context, participation through Social Economy has a significant role, as it encourages and increases the involvement of the local population and different agents in the process.
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