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A new circular position sensor based on giant magnetoresistances has been developed. The sensing film is an AgCo nanogranular thin film patterned in a circular Wheatstone bridge configuration. This alloy shows a high magnetoresistance (8%) at room temperature within the field generated by an NdFeB permanent magnet that provides a sensitivity of 440 μV/V/(°). The operational temperature range of this sensor is -40°C/+120°C, although the magnetic film tolerates higher temperatures up to 200°C. These parameters and the contactless way of sensing make this device appropriate for automotive applications. The developed sensor presents excellent characteristics for life, since it is not sensitive to pollution; it is frictionless and does not present any type of electrical noise generated by contacts. [ABSTRACT FROM PUBLISHER]

Toxic gas detection is a common issue of interest in domestic as well as industrial environments. There are, in fact, accurate methods to measure gas concentrations (Fourier transform infrared, gas chromatographs, or mass spectrometers) but they are too expensive and require skilled operators. Therefore, these complex detection systems are not useful for many applications, such as hazardous gas level detection in domestic appliances. In this paper, investigations lead to the fabrication of a micromachined tin oxide device for carbon monoxide detection in domestic environments. Relevant parameters that influence gas detection are analyzed and thus the device fabrication process defined by means of microtechnologies. Throughout the material optimization for CO detection, three different additive adding methods by dc sputtering PVD technique are studied and compared for two additives: Pt and Pd. [ABSTRACT FROM PUBLISHER]

Abstract: The combustion of methane has been studied over 1% Pd catalysts supported on commercial silica with different hydrophobicity, prepared by chlorine free precursors. It was found that, when no water is added to the feed, the degree of hydrophobicity of the silica does not affect significantly the behavior of the catalysts. The results show that the activation and deactivation processes are similar for both catalysts. Furthermore, contrary to what is observed on Pd/Al2O3 and Pd/ZrO2 catalysts, the apparent reaction order with respect to water for Pd/SiO2 catalysts is -0.25. When water is added to the feed, however, the different hydrophobicity of the supports affects the inhibition produced by the adsorption of water on the catalytic surface. Regardless of the hydrophobicity of the support, the addition of water also speeds up the deactivation process of the Pd catalysts supported on silica. [Copyright &y& Elsevier]

Several sets of staircased Quaternary marine deposits can be observed along the Gibraltar coast ranging from 1 to 210 m above the present mean sea level. Geomorphological mapping establishes, from the relationship between shore, scree and dune sedimentary formations, five main morphotectonic steps on the Rock: marine terraces between 1 and 25 m, 30–60 m, 80–130 m, 180–210 m, and above. Each terrace level and its slope-aeolian linked sediments is backed by a steep relict sea cliff margin, so forming a composite cliff. The most recent coastal landforms and sediments are associated with the last 250 ka linked to Oxygen Isotope Stages (OIS) 1, 3, 5 and 7. These landforms determine a morphosedimentary highstand-lowstand sequence, with several staircased and offlapped episodes, comprising a major morphotectonic step. A well-developed palaeocliff usually separates the highstand marine terraces of OIS 9 from those of OIS 7. The Gibraltar mean tectonic uplift value of 0.05±0.01 mm/yr is maintained from 200 ka to the present. Before this, at least to 250 ka, the mean uplift rate was higher (0.33±0.05 mm/yr), possibly compatible with major tectonic events in response to a NNW–SSE compressive stress field between Africa and Iberia. [Copyright &y& Elsevier]