Push &; Pull: autonomous deployment of mobile sensors for a complete coverage

Mobile sensor networks are important for several strategic applications devoted to monitoring critical areas. In such hostile scenarios, sensors cannot be deployed manually and are either sent from a safe location or dropped from an aircraft. Mobile devices permit a dynamic deployment reconfiguration that improves the coverage in terms of completeness and uniformity. In this paper we propose a distributed algorithm for the autonomous deployment of mobile sensors called Push & Pull. According to our proposal, movement decisions are made by each sensor on the basis of locally available information and do not require any prior knowledge of the operating conditions or any manual tuning of key parameters. We formally prove that, when a sufficient number of sensors are available, our approach guarantees a complete and uniform coverage. Furthermore, we demonstrate that the algorithm execution always terminates preventing movement oscillations. Numerous simulations show that our algorithm reaches a complete coverage within reasonable time with moderate energy consumption, even when the target area has irregular shapes. Performance comparisons between Push & Pull and one of the most acknowledged algorithms show how the former one can efficiently reach a more uniform and complete coverage under a wide range of working scenarios.     

Progress on large area n‐type silicon solar cells with front laser doping and a rear emitter

We report on the progress of imec's n‐type passivated emitter, rear totally diffused rear junction silicon solar cells. Selective laser doping has been introduced in the flow, allowing the implementation of a shallow diffused front surface field and a reduction of the recombination current in the contact area. Simplifications have been implemented towards a more industrial annealing sequence, by replacing expensive forming gas annealing steps with a belt furnace annealing. By applying these improvements, together with an advanced texturing process and emitter passivation by atomic layer deposition of Al₂O₃, 22.5% efficient cells (three busbars) have been realized on commercial 156 · 156 mm² Czochralski‐Si. This result has been independently confirmed by ISE CalLab. Copyright © 2016 John Wiley & Sons, Ltd.     

Resistant starch—An accessible fiber ingredient acceptable to the Western palate

Dietary fiber intakes in Western societies are concerningly low and do not reflect global recommended dietary fiber intakes for chronic disease prevention. Resistant starch (RS) is a fermentable dietary fiber that has attracted research interest. As an isolated ingredient, its fine particle size, relatively bland flavor, and white appearance may offer an appealing fiber source to the Western palate, accustomed to highly refined, processed grains. This review aims to provide a comprehensive insight into the current knowledge (classification, production methods, and characterization methods), health benefits, applications, and acceptability of RS. It further discusses the present market for commercially available RS ingredients and products containing ingredients high in RS. The literature currently highlights beneficial effects for dietary RS supplementation with respect to glucose metabolism, satiety, blood lipid profiles, and colonic health. An exploration of the market for commercial RS ingredients indicates a diverse range of products (from isolated RS2, RS3, and RS4) with numerous potential applications as partial or whole substitutes for traditional flour sources. They may increase the nutritional profile of a food product (e.g., by increasing the fiber content and lowering energy values) without significantly compromising its sensory and functional properties. Incorporating RS ingredients into staple food products (such as bread, pasta, and sweet baked goods) may thus offer an array of nutritional benefits to the consumer and a highly accessible functional ingredient to be greater exploited by the food industry.     

Structure-composition relationships of the Traditional Balsamic Vinegar close to jamming transition

The Traditional Balsamic Vinegar of Modena (TBVM), an Italian valuable specialty produced from cooked grape must becomes viscous through a long-ageing process. TBVM may undergo jamming transition which causes its depreciation. A liquid and jammed TBVM were investigated for their microstructure and elemental composition by coupling two non-destructive techniques, i.e. Environmental Scanning Electronic Microscopy (ESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The same samples were also analyzed for their molecular size distribution by Size Exclusion Chromatography (SEC) and their shear viscosity with a stress-controlled rheometer. TBVM in the jammed state behaved as a pseudoplastic fluid due to the presence of nitrogen-free polymers with a molecular size dispersion lower than a liquid TBVM, the latest showed the Newtonian flow behavior. TBVM solid particles detected close to jamming transition showed a C/O ratio of 2.5 (liquid TBVM) and 3.7 (jammed TBVM), thus much higher than the main TBVM constituents (glucose, fructose and acetic acid). The Fe and Mg content was higher and pH was lower in the jammed TBVM. It was hypothesized that jamming transition in TBVM was the result of the unbalance between two time-dependent phenomena, i.e. the increase of the bulk viscosity and the structure relaxation of nitrogen-free polymers.     

VFC-SMOTE: very fast continuous synthetic minority oversampling for evolving data streams

Data Mining and Knowledge Discovery - The world is constantly changing, and so are the massive amount of data produced. However, only a few studies deal with online class imbalance learning that...     

A theoretical analysis of a buffer frame size conversion algorithm for audio applications ensuring minimum latency

In implementing digital signal processing (DSP) algorithms for audio real-time applications, one is frequently faced with problems regarding incompatibilities between the hardware buffer length (the internal buffer of a professional sound card) and the software buffer size imposed by the underlying algorithm (due to i.e. multirate or FFT constraints). This mismatch is solved by proper frame size conversion algorithms which inevitably introduce delay. In this context, this paper presents a buffering scheme together with a theoretical proof of the minimum delay property shown by it. Some examples derived from frequently encountered issues in DSP applications are reported.     

Novel quasi-autothermal hydrogen production process in a fixed-bed using a chemical looping approach: A numerical study

This paper presents a novel quasi-autothermal hydrogen production process. The proposed layout couples a Chemical Looping Combustion (CLC) section and a Steam Methane Reforming (SMR) one. In CLC section, four packed-beds are operated using Ni as oxygen carrier and CH₄ as fuel to continuously produce a hot gaseous mixture of H₂O and CO₂. In SMR section, two fixed-beds filled with Ni-based catalyst convert CH₄ and H₂O into a H₂-rich syngas. Four heat exchangers were employed to recover residual heat content of all the exhaust gas currents. By means of a previously developed 1D numerical model, a dynamic simulation study was carried out to evaluate feasibility of the proposed system in terms of methane conversion (100% circa), hydrogen yield (about 0.65 mol_H2/mol_CH4) and selectivity (about 70%), and syngas ratio (about 2.3 mol_H2/mol_CO). Energetic and environmental analyses of the system performed with respect to conventional steam methane reforming, highlights an energy saving of about 98% and avoided CO₂ emission of about 99%.     

An electrochemical impedance investigation of the behaviour of anodically oxidised titanium in human plasma and cognate fluids,relevant to dental applications

In dental applications, the contact between the metal implant and the receiving living tissue is made through the oxide layer on the implant surface, which allows the osseointegration process. In dentistry, the passive film formed on titanium seems to be more stable and protective than that formed on the Ti alloys, customarily used in other medical applications. Corrosion of titanium alloys in the mouth can result from the presence of a number of corrosive species, such as the hydrogen ion (H(+)), sulfide compounds (S(2-)), dissolved oxygen (O(2)) and Cl(-) and can result in the release of Ti(4+) ions that, in turn, brings about the reduction of alkaline phosphatase activity of osteoblastic cells. The present study reports a time-dependent electrochemical corrosion study of titanium in contact with the following biologically relevant solutions: (i) SBF (simulating the inorganic part of human plasma), (ii) SBF with added ovalbumin (a protein simulating the post-implant environment) and (iii) human plasma. To the best of the authors' knowledge, this is the first report on the corrosion of Ti in human plasma. The electrochemical measurements are based on electrochemical impedance spectrometry. Impedance spectra were interpreted on the basis of the equivalent-circuit approach and estimates of the time-variation of oxide film thickness and resistance were computed. Surface Raman spectroscopy was used to characterise the structure of as-anodised and corroded TiO(2) films: the effects of phosphate and organic incorporation were highlighted. EIS and surface Raman measurements have demonstrated that the corrosion resistance of the oxide films formed on Ti is strongly affected by the presence of biomolecules in the chloride- and phosphate-based aqueous solution. In particular, ovalbumin increases corrosion performance and human plasma is found to be remarkably more aggressive in comparison to SBF. These results suggest some caution in extrapolating corrosion results obtained in simulated biological fluids to the actual behaviour in vivo.     

Polyphasic characterization of indigenous lactobacilli and lactococci from PDO Canestrato Pugliese cheese

A polyphasic approach, involving both genotypic and phenotypic analyses was used to characterize 33 isolates of lactic acid bacteria from the raw milk Protected Designation of Origin (PDO) Canestrato Pugliese cheese, in order to select candidate strains that can be used as autochthonous starter cultures in the dairy industry. Randomly amplified polymorphic DNA (RAPD) analysis and clustering by the unweighted pair-group method with arithmetic averages (UPGMA) were used to evaluate the genotypic diversity, while phenotypic characterization was performed through miniaturized assays and traditional biochemical tests. Technological properties of major interest for cheese-making (acidification, tendency to lysis, proteolytic and peptidase activity) were also evaluated, and selected subset of data was statistically examined by the one-way ANOVA and the Tukey-Kramer HSD test, to highlight strain-specific and species-specific differences among the isolates. A high degree of diversity appeared in the phenotypic and technological traits in opposition to a relatively low genotypic diversity. Although none of the isolates showed the best performances in all the activities, an appropriate mixture of strains could be selected for providing an efficacious autochthonous starter culture.     

Public Sector Alternatives to Water Supply and Sewerage Privatization: Case Studies

The paper presents a consideration of public sector operations as an alternative to the privatization of water and sewerage services. Cross-country case studies of publicly owned enterprises which have succeeded in reconciling efficiency and social purposes and carrying out structural and managerial changes are compared with some experiences of privatized concessions. Overall, public enterprises appear no less efficient that private companies, while being capable of development-oriented consideration of public interests.