Foot-turistic multimedia: designing interactive multimedia installations for shoe shops

The amount of money spent in a store is positively correlated with the amount of time spent inside. We argue this is an opportunity for multimedia installations that can entertain shoppers and promote interaction with the shop??s products. This was the main principle behind our design idea for two interactive installations specifically conceived for shoe shops. We present two applications of interactive multimedia to shoe shopping: an interactive semantic mirror and an interactive window logo. We also describe the results of ethnographic studies, before and after the design process. Our contribution is two-fold: (i) we develop and apply a new multimedia architecture that combines RFID in-store technology with high-end motion detection algorithms, and (ii) we describe one of the first few studies about multimedia installations for improving the shoe shopping experience, in what we call ??foot-turistic?? interactions.     

Electrochemical and structural characterization of copper recycled from anodes of spent Li-ion batteries

In this study, the charge efficiency, nucleation growth, and morphology of electrodeposited copper from spent Li-batteries were studied. The charge efficiency for these deposits shows a maximum value of 99.41%, under a charge density of 5.0 C cm^?2. Studies with the SEM technique at pH 2.0 show well-formed nuclei. At pH 4.5, the deposits take the form of dendrites. XRD analysis shows that, in both cases, a Cu₂O structure is present, but with a large amount at pH 4.5, evidenced by peaks of [002] and [110] directions.     

Evaluation of the impact of access to electricity: A comparative analysis of South Africa,China, India and Brazil

Most developing countries include rural electrification programs in their efforts to improve social conditions. There are, however, several obstacles to the evaluation of such programs and therefore of their social, economic, environmental and energy impacts on the target population, particularly on impoverished communities located in remote areas. Evaluation of the efficacy of public policies aimed at rural electrification in South Africa, China, India and Brazil enables such actions to be quantified and re-considered so as to bolster the sustainability of their planning and implementation and also so as to enable comprehension of the significance of access to electricity in relation to other aspects of the drive to improve living standards. The provision of electric energy amounts to more than access to a public service and should be considered an essential right, in a context of social equity and justice, which permits social integration and the access to other equally essential services.     

CO and methanol electrooxidation on Pt/Ir/Pt multilayers electrodes

This work describes the CO and methanol electrooxidation over an Ir/Pt bilayer electrodeposited on a platinum polycrystalline substrate. In the blank acidic solution it was observed that the electrochemical behavior of both the polycrystalline Pt and Pt/Ir/Pt nanostructured electrodes were very similar. The electroactive area, calculated using the hydrogen desorption method, are the same for both materials. In order to investigate the effect of the thickness change of Ir interlayer, two different samples were prepared. One with 1 Ir monolayer and the second with 3 monolayers thick. CO stripping voltammograms showed a shift in the anodic peak potential towards the negative direction of 160 and 180 mV for Pt/Ir/Pt 3:1 and 1:1 ML, respectively, compared to polycrystalline Pt. Besides, for methanol electrooxidation, the Pt/Ir/Pt electrodes presented an increase of 170% in the peak current density compared to polycrystalline Pt. These results are in agreement with the calculated activation energies which were 31.5, 39.0 and 43.5 kJ mol⁻¹ for Pt/Ir/Pt 1:1, 3:1 ML and polycrystalline Pt electrodes, respectively. Using the electrochemical impedance spectroscopy, surprisingly, the Pt/Ir/Pt electrodes, did not exhibit the inductive arc which means that the poisoning of the electrode surface is not important in this case.     

Electrical characteristics of magnetic memory cells comprisingmagnetic tunnel junctions and GaAs diodes

Magnetic tunnel junctions have been the subject of study for use in nonvolatile magnetic memories. To cancel leakage paths in the memory array, a semiconductor switch is integrated per cell. Successful integration with GaAs diodes, dominating the cell performance, is described. Good resistance matching between both elements is essential to optimise the output characteristics. i.e. the absolute voltage or current difference between the two magnetic states     

Failure analysis of a gear wheel of a marine azimuth thruster

A failure analysis of two helical gear wheels of a ducted azimuth thruster is presented. The research work consisted of a fracture examination of the material in order to determine the damage root causes. The samples for the failure analysis were obtained from two broken teeth of two helical gear wheels. An analysis through the scanning electron microscope (SEM) was carried out close to the crack initiation. It was found that the damage in the bevel gears were by the fatigue fracture mode. The SEM analysis showed that the gear teeth were under severe contact stress during the operation aggravated by an inappropriate lubricating. A possible misalignment between the pinions and the gear wheels teeth could also contribute for the premature failure.     

Expected render performance assessment based on impact resistance in situ determination

External renders must fulfil certain functions to ensure a good in-service performance of façades such as: waterproofing and protection of the walls, finishing of the surfaces, durability in face of the external degradation agents, and adequacy to use. Defective surface resistance of the renders (significant deterioration under impact and friction actions inherent to the normal use of the building) accelerates the degradation process, leading to a significant loss of physical and aesthetical performance. Based on laboratory experimental testing and on-site investigation, with various types of renders and using the Martinet-Baronnie device, the parameters of surface resistance are discussed, in terms of resistance to the impact of hard objects (with and without cutting edges). The results allowed criteria to be proposed for the in situ assessment of external renders in buildings with brick masonry walls (characterization of predicted surface impact resistance in-service conditions).     

Failure prediction of composite T-beams subjected to lateral load on the web

A study of the design and mechanical behaviour of co-cured T-beams subjected to lateral loading on the web is presented. The T-beams were manufactured by press moulding from pre-pregs of uni-directional and fabric glass reinforced high performance epoxy matrix. A special fixture was designed in order to carry out tests where the T-beams were laterally loaded on the web and clamped on the flange. Analytical and numerical studies were performed to predict the failure load to compare with the experimental results. The multilayer anisotropic continuum theory for delamination analysis of curved beams subjected to end moments and forces was used to compute the delamination stresses in the quarter cylindrical beam of the junction between the flange and the web. Finite element analyses of the T-beams were performed using plate/shell elements and two models were used for the joining between web and flange, to compute the planar stresses in the beam. The scatter obtained in the experimental results can be explained by the presence of two failure modes: one due to delamination associated with the through the thickness stresses developed in the curved part of the beam, the other related with failure occurring due to tangential stresses in the most highly stressed plies.     

Effect of shear displacement on the aperture and permeability of a rock fracture

The results of experiments using radial and unidirectional flow in a carefully described single rough aperture are reported and compared with numerical predictions. Aperture replicas of a natural sandstone fracture were made at 0, 1 and 2 mm shear displacements using silicone rubber, with a reproducibility of better than 2%. The experimental arrangement permitted shear displacement to be obtained without causing damage to the two displaced surfaces, which thus retained their original (and essentially matching) geometry. Both the number of contact points and the fractional contact area decreased with increasing shear displacement. With increasing shear displacement, mean aperture and standard deviation increased and the ratio of standard deviation to mean aperture increased slightly. Semivariogram studies indicated that as shear displacement increased in the direction normal to the roughness ridges, the aperture distribution became more closely correlated in the direction parallel to the roughness ridges than in the shear direction. Flow tests showed that with increasing shear displacement, the fracture became heterogeneous and anisotropic and became more permeable in the direction perpendicular to the shear displacement than in the direction parallel to the displacement. Simulations were made of flow through the fracture using the Reynolds equation and the actual aperture distribution; the measured hydraulic apertures were generally about 20% lower than those measured numerically.     

Resource competition as a mechanism for B cell homeostasis

Cellular competition for survival signals offers a cogent and appealing mechanism for the maintenance of cellular homeostasis [Raff, M. C. (1992) Nature (London) 356, 397-400]. We present a theoretical and experimental investigation of the role of competition for resources in the regulation of peripheral B cell numbers. We use formal ecological competition theory, mathematical models of interspecific competition, and competitive repopulation experiments to show that B cells must compete to persist in the periphery and that antigen forms a part of the resources over which B cells compete.