Electrode surface treatments in sludge electro-osmosis dewatering

The sewage sludge dewatering produced by wastewater treatment plants (WWTP) is a multifaceted process due to the presence of colloid fractions. Electro-osmosis could be a suitable technique to reduce the water content of the final sludge. Electric fields of 10, 15, and 20?V/cm have been studied for electro-osmosis tests under the pressure of a static or rotating piston, obtaining a dry solids content up to 40–45%, with respect to 25–30% obtained by mechanical methods. In order to optimize the process, the corrosion behavior and the wear of the anodic material appear to be the main critical aspects, due to the high circulating current density and the use of a rotating electrode. We compared the efficiency and the corrosion resistance of dimensionally stable anodes (DSA) with respect to bare stainless steel (AISI 304) and stainless steel coated by PVD technique with TiN, AlTiN, and DLC. Characterization of the anode surfaces by SEM and potentiodynamic tests show that DSA is the most suitable material for our application. However, efficiencies of the electro-osmosis processes have been found comparable, in terms of developed current densities and total energy consumptions, for short-test duration.     

Data reconciliation in a smart home sensor network

This paper describes a data-driven approach to sensor data validation. The data originates from a network of sensors embedded in an indoor environment such as an office, home, factory, public mall or airport. Data analysis is performed to automatically detect events and classify activities taking place within the environment. Sensor failure and in particular intermittent failure, caused by electrical interference, undermines the inference processes. PCA and CCA are compared for detecting intermittent faults and masking such failures. The fault detection relies on models built from historical data. As new sensor observations are collected the model is updated and compared to that previously estimated, where a difference is indicative of a failure.     

Optimal radio resources and transmission formats assignment in OFDMA systems

The problem of assigning radio resources and transmission formats to users in the downlink of an OFDMA network is addressed. In particular, a single cell environment with a realistic interference model and a margin adaptive approach is considered, i.e., the aim is of minimizing the total transmission power while maintaining a certain given rate for each user. The computational complexity issues of the problem are discussed, and an approximation analysis is presented. Heuristic approaches, based on rounding techniques and graph models, are also proposed. Computational experiences show that, in a comparison with a commercial state-of-the-art optimization solver and with alternatives from the literature, the proposed algorithms are effective in terms of solution quality and CPU times.     

Investigation of the mechanisms governing doxorubicin and irinotecan release from drug-eluting beads: mathematical modeling and experimental verification

Drug-eluting beads (DEBs) are embolising devices in clinical use for the treatment of liver cancer by transarterial chemoembolisation. In this study, release kinetics of doxorubicin (DOX) and irinotecan (IRI) were investigated by experimental evaluations and mathematical modeling, based on Langmuir isotherm and two phenomenological models (Boyd/Bhaskar) developed to determine the actual mechanisms controlling drug release rate. The model was validated through release studies, in particular by assessing how drug loading, ionic strength of the release medium and device swelling during release influence drug release kinetics. Results demonstrated that IRI is released much faster than DOX, and that DEB volume strongly depends upon drug loading and fractional release. This effect was properly taken into account in developing the mathematical model. Experimental results were well fit by numerical simulations, and two different rate-controlling mechanisms were found to govern DOX and IRI delivery.     

Kenaf‐filled biodegradable composites: rheological and mechanical behaviour

Biodegradable polymer composites, typically based on biodegradable polymer matrices and natural‐organic fillers, are gaining rising interest and importance over the last few years. Several natural‐organic fillers can be used but the most widespread so far is wood, in the form of fibres or flour. Alternative cellulosic fillers can ensure advantages in terms of resource utilization and properties of the final composite. In this work, Mater‐Bi^® based biodegradable composites were prepared with two kinds of wood flour, and directly compared with alternative composites containing kenaf fibres. The use of kenaf fibres allowed improved elastic modulus, tensile strength and interaction with the polymer matrix to be obtained, although the filler dispersion was worse. Rheological measurements evidenced higher viscosity and an increasingly elastic behaviour of the melt. Copyright © 2012 Society of Chemical Industry     

Diet supplementation with donkey milk upregulates liver mitochondrial uncoupling,reduces energy efficiency and improves antioxidant and antiinflammatory defences in rats

Dietary PUFA, mainly those of the n‐3 family, are known to play essential roles in the maintenance of energy balance and in the reduction of body fat deposition through the upregulation of mitochondrial uncoupling that is the main source of reactive oxygen species. We hypothesized that rat supplementation with raw donkey's milk (DM), characterized by low‐fat content and higher n3:n6 ratio, may affect energy balance, lipid metabolism, and prooxidant status as compared to animals treated with cow's milk. In the present study, the effects of drinking raw DM (for 4 weeks) on energy balance, lipid metabolism, antiinflammatory, and antioxidant/detoxifying defences was compared to that produced by rat intake of an iso‐energetic amount of raw cow's milk. The hypolipidemic effect produced by DM paralleled with the enhanced mitochondrial activity/proton leakage and with the increased activity or expression of mitochondrial markers namely, carnitine palmitoyl transferase and uncoupling protein 2. The association of decreased energy efficiency with reduced proinflammatory signs (TNF‐α and LPS levels) with the significant increase antioxidant (total thiols) and detoxifying enzyme activities (glutathione‐S‐transferase NADH quinone oxidoreductase) in DM‐treated animals, indicated that beneficial effects were attributable, at least in part, to the activation of nuclear factor 2 erythroid‐related factor 2 pathway.     

Double diffusion in rotating porous media under general boundary conditions

In this article we study a binary fluid saturating a rotating porous medium; the fluid is modeled according to Darcy–Brinkman law and the boundary conditions are rigid or stress-free on the velocity field and of Robin type on temperature and solute concentration.We determine the threshold of linear instability and its dependence on Taylor and Darcy numbers. Using a Lyapunov function we prove analytically, under certain assumptions, the coincidence of linear and nonlinear thresholds. A second Lyapunov function allows us to prove numerically the coincidence of the two thresholds with weaker assumptions on the parameters.We show that in the particular limit case of fixed heat and solute fluxes this system has a remarkable feature: the wave number of critical cells goes to zero when the Taylor number is below a threshold. Above such threshold, the wave number is non-zero when the Darcy number belongs to a finite interval. These phenomena could perhaps be tested experimentally.     

A smartphone-based fall detection system

Falls are a major cause of injuries and hospital admissions among elderly people. Thus, the caregiving process and the quality of life of older adults can be improved by adopting systems for the automatic detection of falls. This paper presents a smartphone-based fall detection system that monitors the movements of patients, recognizes a fall, and automatically sends a request for help to the caregivers. To reduce the problem of false alarms, the system includes novel techniques for the recognition of those activities of daily living that could be erroneously mis-detected as falls (such as sitting on a sofa or lying on a bed). To limit the intrusiveness of the system, a small external sensing unit can also be used for the acquisition of movement data.