Jesús Barrasa Rodríguez

Upgrading relational legacy data to the semantic web

In this poster, we describe a framework composed of the R2O mapping language and the ODEMapster processor to upgrade relational legacy data to the Semantic Web. The framework is based on the declarative description of mappings between relational and ontology elements and the exploitation of such mapping descriptions by a generic processor capable of performing both massive and query driven data upgrade.

Temperature effects on the wear behavior of particulate reinforced Al-based composites

Particulate reinforced Al-based composites exhibit lower wear rates in comparison to the unreinforced monolithic alloys. To study the influence of temperature on the tribological behavior of two aluminum alloys, 2014 and 6061, reinforced with aluminum oxide particles, wear tests were carried out in an oscillating friction machine with tempered steel spheres as counterbodies in the temperature range 293 to 473 K. Examination of the worn specimens by scanning electron microscopy clarified the prevailing physical mechanism of wear in these materials. The test results were also used to determine wear resistance and friction coefficient vs. temperature. Numerical modeling by finite elements has been carried out to investigate the actual stress state near the contact.

Modeling the effect of temperature on the wear resistance of metals reinforced with ceramic particles

Abstract The wear resistance of a 2014 Al alloy reinforced with Al 2 O 3 ceramic particles was studied as a function of temperature. The wear rate increased with temperature and a transition from mild to severe wear was detected above 170°C. A zone containing comminuted ceramic particles was found below the contact surface, and the thickness of this region was proportional to the wear rate in the whole temperature range. Three-dimensional finite element analyses were carried out to compute the stresses in the composite as a function of the distance to the contact surface. They were used to estimate the stresses acting on the ceramic particles and to calculate the thickness of the fragmented-particle region. The theoretical results were in agreement with the experimental data, and they illustrate the effect of temperature on the wear resistance of metals reinforced with ceramic particles.

Materials selection to excavator teeth in mining industry

Abstract Hard alloys are normally used as materials for excavators teeth in mining industry. In most cases these alloys do not have enough anti-wear properties and coatings are employed as a good alternative. The objective of this work is to test the abrasive wear resistance of several cast irons alloyed with different elements. Laboratory tests based on the ASTM G105-89 standard were compared to tests carried out under real working conditions of excavator teeth in mines. The experimental results show an acceptable correspondence between laboratory and field tests. To complete the laboratory research, hardness and microhardness measurements and optical micrographs were performed to identify the mechanism of wear. As a result of the experimental work, an economic evaluation of materials was also performed.

Semantic Upgrade and Publication of Legacy Data

Nowadays an enormous quantity of data can be found on web pages generated from relational databases. This information is often referred to as the Deep Web [7] as opposed to the surface web comprising static web pages. The same can be said about almost every organization’s legacy data which usually hides behind all kinds of applications, and publishing systems like intranets, web portals, blogs, etc. For these large amounts of data the challenge is no longer to head for better performances, i.e., to store more and more information in less space and to answer queries faster; the database community has realized that now it is all about the provision of “smart information”, information which can easily be interchanged, combined, integrated among systems and processes or automatically reasoned about. In other words, we face the challenge of “upgrading” this large amount of existing content into Semantic Web content. But this challenge clashes with a huge problem: that of the absence of explicit data semantics. These two ideas are summarized in the following quotation appearing in [10]:

Effect of cold deformation on the abrasive resistance of coatings with applications in the mining industry

Abstract Machinery components of the mining industry are often involved in severe wear processes. This is the case of the support wheels of the crawler track of the excavators in the open cast mine. Surface coating technologies are essential to improve the surface performance of such components. In this work, the effect of cold deformation on the wear resistance of several Fe–Cr–Mn alloys welding coated over a steel substrate is studied. After being coated, the specimens were pressed by means of a block hammer which produced surface distortion and thickness variation. This deformation process generates micro structural changes and material which may improve the abrasive wear resistance. Abrasion wear tests were carried out based on the standard test method for conducting wet sand/rubber wheel abrasion tests (ASTM G105-89).

A semantic portal for fund finding in the EU: semantic upgrade, integration and publication of heterogeneous legacy data

FundFinder is a Semantic Web portal that allows searching for and navigating through information about funding opportunities. This application has been created following a set of techniques and using a set of tools for the upgrade of legacy content to the Semantic Web, including databases and semi-structured documents. This process consists in extracting and populating knowledge from heterogeneous information sources and making it available on the Web.