Safety First? Users’ Perception of Wearable Sensor Networks for Aging

Mobile Networks and Applications - Population aging is considered to be one of the most significant social transformations of the twenty-first century. In this paper, we evaluate the acceptability...     

Surface functionalization of bioactive glasses and hydroxyapatite with polyphenols from organic red grape pomace

An extract of polyphenols was obtained from organic red grape pomace, chemically analyzed, and used for functionalization of two bioactive glasses and porous hydroxyapatite. Functionalization is effective on hydroxyapatite and the bioactive glass with higher surface reactivity with a different grafting mechanism. Grafting does not inhibit redox and radical scavenging activity of polyphenols. The grafted polyphenols make a continuous layer with an almost complete surface coverage. Polyphenols are released with different kinetics according to the mechanism of grafting and maintain their redox activity. A homogeneous thin layer of polyphenols is still firmly grafted on both substrates after 28 days of soaking and it still maintains radical scavenging activity. The functionalized samples can be sterilized by gamma irradiation.     

Engineering Design Study on an Innovative Hydrokinetic Turbine with on Shore Foundation

Tidal currents are a resource of great potentiality and not yet fully explored. Several efforts have been made to exploit these resources, but the costs associated to the deployment of tidal plants in marine environments are usually too high. The aim of this work is to present a system able to handle with the above mentioned problems, through the development of a particular hydrokinetic turbine design. In previous works, the authors described a basic turbine configuration achieving interesting performances, although some operational inconveniences were detected. Those problems have been existing so the solution should be optimized and redesigned. As a result, a new design of the turbine is proposed, consisting of a double rotor spinning in opposite directions in order to balance the induced mechanical torque. From preliminary evaluations related to the Messina Strait tidal cycles （Punta Pezzo site, RC, Italy）, a single 12 m diameter turbine can supply a power of about 500 kW with a peak current speed of 3 m/s and deliver up to 450 MWh/year.     

On the form and function of forgiving: Modeling the time-forgiveness relationship and testing the valuable relationships hypothesis.

In two studies, the authors sought to identify the mathematical function underlying the temporal course of forgiveness. A logarithmic model outperformed linear, exponential, power, hyperbolic, and exponential-power models. The logarithmic function implies a psychological process yielding diminishing returns, corresponds to the Weber-Fechner law, and is functionally similar to the power law underlying the psychophysical function (Stevens, 1971) and the forgetting function (Wixted & Ebbesen, 1997). By 3 months after their transgressions, the typical participant's forgiveness had increased by two log-odds units. Individual differences in rates of change were correlated with robust predictors of forgiveness. Consistent with evolutionary theorizing (McCullough, 2008), Study 2 revealed that forgiveness was uniquely associated with participants' perceptions that their relationships with their offenders retained value. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can weathering improve the toughness of a fractured rock? A case study using the San Giacomo granite

The physical–mechanical behaviour of the weathered San Giacomo granite, Sardinia, has been investigated using a combination of physical–mechanical tests and microstructural analysis. Fieldwork and microscopy suggest a pervasive microfracture system developed on a pre-existing magmatic quartz anisotropy. Alteration indices, chemical analyses and mineralogy indicate that the yellow staining is produced by the circulation of oxygen-rich rainwater through microfractures in the rock, resulting in the oxidation of biotites. Apart from the obvious modification of the original grey colouring, the precipitation of Fe-oxides and hydroxides has welded fractures together, leading to the partial recovery of the physical–mechanical properties previously compromised due to microfracturing.     

A Cortical-Inspired Geometry for Contour Perception and Motion Integration

In this paper we develop a geometrical model of functional architecture for the processing of spatio-temporal visual stimuli. The model arises from the properties of the receptive field linear dynamics of orientation and speed-selective cells in the visual cortex, that can be embedded in the definition of a geometry where the connectivity between points is driven by the contact structure of a 5D manifold. Then, we compute the stochastic kernels that are the approximations of two Fokker Planck operators associated to the geometry, and implement them as facilitation patterns within a neural population activity model, in order to reproduce some psychophysiological findings about the perception of contours in motion and trajectories of points found in the literature.     

Cellulose as a renewable resource for the synthesis of wood consolidants

Crosslinkable cellulose ethers as allyl cellulose, allyl carboxymethyl cellulose, and allyl n‐hydroxypropyl cellulose were synthesized and characterized, and their use as consolidating agents for waterlogged wood was studied. For this kind of application, structural properties similar to those of wood's polysaccharide components are desired in the design stage of new consolidants. The choice to synthesize cellulose ethers was determined from the possibility of using cellulose as the starting material because of its large availability in nature, biocompatibility, and low cost. In addition, cellulose ethers are quite easy to obtain, and they can have different properties, depending on the nature and the amount of the functional groups introduced. For this purpose, a cellulose with a lower degree of polymerization was also used for the synthesis of related cellulose ethers. By means of Fourier transform infrared spectroscopy, the affinity of the cellulose derivatives for degraded lignin flours was detected. The preliminary results of this study show that these polysaccharide compounds may be proposed as wood consolidating agents. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

REMARKS ON THERMODYNAMIC DIAGRAMS WITH SPECIFIC CONSIDERATIONS FOR “ INVARIANT” PROPERTIES

When the aim is a qualitative examination of thermodynamic phenomena and processes of two independent variable systems, the various state diagrams ( p vs. v; T vs. s; i vs. s; p vs. i, etc.) are very useful. Every one of these diagrams is suitable to put in evidence some topics, whereas other ones cannot be displayed. That is unavoidable since all topics can be displayed only by means of a three-dimension representation

The several diagrams, even if very different among them, have some common properties. The main aim of this paper is that of examining one property which seems interesting for the analysis of such diagrams: the order, according to which the different processes ( isobaric, isothermal, isentropic, isenthalpic, isochoric) depart from a given point, is invariable, even if this order is different in the various zones of the diagrams. In addition, other properties of some diagrams are considered     

Synthesis,consolidation and characterization of monolithic and SiC whiskers reinforced HfB2 ceramics

Spark Plasma Sintering is used for the fabrication of highly dense HfB₂ monolithic and HfB₂–26 vol.% SiC_w composite. Reactive SPS from elemental reactants is preferred for the preparation of bulk HfB₂ instead of classical sintering. The desired phase is rapidly formed through a solid–solid combustion synthesis mechanism, while full densification is achieved in 30 min at 1350 A when the applied pressure is switched from 20 to 50 MPa after the synthesis reaction. A 99.4% dense whiskers-reinforced HfB₂ ceramic matrix composite is also obtained in 30 min by SPS (I = 1350 A, P = 20 MPa) using SHSed HfB₂ powders and SiC_w. Nevertheless, whiskers degradation into SiC_p resulted under such conditions (temperature up to 1830 °C). On the other hand, the presence of whiskers is clearly evidenced in 96% dense products obtained when the applied current was decreased down to 1200 A (1700 °C) while P was increased to 60 MPa.