Impact of antioxidants dispersions on the stability and oxidation of water-in-olive-oil emulsions

Water-in-olive-oil emulsion stability was studied as a function of the composition of the water dispersed phase. In particular, different polyphenolic extracts from natural sources were dispersed in the olive oil and their impact on emulsion kinetic stability and susceptibility to oxidation was evaluated. As natural sources, extra virgin olive oil, olive mill waste and green tea leaves were chosen. To test their impact on emulsion properties, the emulsions were prepared with fixed aqueous phase content. As emulsifiers, a fixed percentage of a mixture Span 80 (sorbitan monoleate)/Tween 80 (polysorbate 80) was used. The effect of the antioxidant dispersion on emulsion oxidation was studied by triggering the oxidation reaction in the oil phase with the lipophilic radical initiator AMVN (2,2-azobis(2,4-dimethylvaleronitrile). Then, the oxidation reaction was followed by using diphenyl-1-pyrenylphosphine, which becomes fluorescent when it is oxidized by hydroperoxides. The impact of antioxidant dispersions on emulsion kinetic stability was studied by UV–Vis turbidity measurements. The oxidation results were correlated to antioxidant extracts oxygen radical adsorption capacity (ORAC) and to emulsion kinetic stability. On the whole, antioxidants dispersions delayed the oxidation reaction to different extents in dependence on their ORAC values and their components amphiphilicity. Remarkably, among the antioxidants tested, the aqueous polyphenol extract from virgin olive oil was the most effective because it protected emulsions both from oxidation and from phase separation. Additionally, from this set of experiments, the primary role of the interfacial properties of olive oil polyphenols was highlighted.     

Metastatic carcinoma to the mandible. Report of two cases

Two cases of rare metastases from malignant neoplasms to the posterior mandible in young adults are reported. Multiple imaging modalities were necessary to identify the many metastases and, in one case, the suspected primary site. Many of the radiographic images are presented for that case.     

Ion implantation doping of Si for optoelectronic applications

We show that the major problems hampering efficient performances of Si in optoelectronic applications, i.e. the achievement of efficient light emission and fast modulation, can be successfully approached by a proper engineering of its optical properties. In particular, the incorporation of a high Er concentration, if concomitant with codoping with other impurities such as O and F, allows to achieve efficient 1.54 μm light emission at room temperature. This emission arises from an electrically excitable, atomically sharp, intra 4f transition of the Er ions. The formation of impurity-rare earth ion complexes is shown to enhance the effective solubility of Er in Si and optimize its electrical properties thus providing a higher excitation efficiency and a reduction of the temperature quenching of the luminescence yield. Furthermore we show that the proper design of a Si light emitting diode, allowing the incorporation of Er ions within the depletion layer region of a p⁺-n⁺ junction, allows to achieve simultaneously high efficiency and fast modulation of the electroluminescence signal. In fact, under reverse bias, Er ions are pumped with a cross section of 6 × 10⁻¹⁷ cm² and decay with a lifetime of 100 μs, which guarantees an internal quantum efficiency > 10⁻⁴ and an emitted power of 30 μW at room temperature. On the other hand, at the diode turn-off, the onset of fast, non-radiative, Auger-type decay processes of the excited ions allow a very fast turn off of the electroluminescence signal.     

Calibration of the EDELWEISS cryogenic heat-and-ionization germanium detectors for dark matter search

Several aspects of the analysis of the data obtained with the cryogenic heat-and-ionization Ge detectors used by the EDELWEISS dark matter search experiment are presented. Their calibration, the determination of their energy threshold, fiducial volume and nuclear recoil acceptance are detailed.     

A User‐based Visual Analytics Workflow for Exploratory Model Analysis

Many visual analytics systems allow users to interact with machine learning models towards the goals of data exploration and insight generation on a given dataset. However, in some situations, insights may be less important than the production of an accurate predictive model for future use. In that case, users are more interested in generating of diverse and robust predictive models, verifying their performance on holdout data, and selecting the most suitable model for their usage scenario. In this paper, we consider the concept of Exploratory Model Analysis (EMA), which is defined as the process of discovering and selecting relevant models that can be used to make predictions on a data source. We delineate the differences between EMA and the well‐known term exploratory data analysis in terms of the desired outcome of the analytic process: insights into the data or a set of deployable models. The contributions of this work are a visual analytics system workflow for EMA, a user study, and two use cases validating the effectiveness of the workflow. We found that our system workflow enabled users to generate complex models, to assess them for various qualities, and to select the most relevant model for their task.     

An Analysis of the Interaction Between Intelligent Software Agents and Human Users

Interactions between an intelligent software agent (ISA) and a human user are ubiquitous in everyday situations such as access to information, entertainment, and purchases. In such interactions, the ISA mediates the user’s access to the content, or controls some other aspect of the user experience, and is not designed to be neutral about outcomes of user choices. Like human users, ISAs are driven by goals, make autonomous decisions, and can learn from experience. Using ideas from bounded rationality (and deploying concepts from artificial intelligence, behavioural economics, control theory, and game theory), we frame these interactions as instances of an ISA whose reward depends on actions performed by the user. Such agents benefit by steering the user’s behaviour towards outcomes that maximise the ISA’s utility, which may or may not be aligned with that of the user. Video games, news recommendation aggregation engines, and fitness trackers can all be instances of this general case. Our analysis facilitates distinguishing various subcases of interaction (i.e. deception, coercion, trading, and nudging), as well as second-order effects that might include the possibility for adaptive interfaces to induce behavioural addiction, and/or change in user belief. We present these types of interaction within a conceptual framework, and review current examples of persuasive technologies and the issues that arise from their use. We argue that the nature of the feedback commonly used by learning agents to update their models and subsequent decisions could steer the behaviour of human users away from what benefits them, and in a direction that can undermine autonomy and cause further disparity between actions and goals as exemplified by addictive and compulsive behaviour. We discuss some of the ethical, social and legal implications of this technology and argue that it can sometimes exploit and reinforce weaknesses in human beings.     

Defects in nanostructures with ripened InAs/GaAs quantum dots

InAs/GaAs quantum dot (QD) structures were grown by molecular beam epitaxy (MBE) with InAs coverages θ continuously graded from 1.5 ML to 2.9 ML. A critical coverage of 2.23 ML is found, above which the islands undergo ripening, which causes a fraction of quantum dots to increase in size and to eventually relax through the formation of pure, edge-type misfit dislocations which propagate towards the surface in the form of V-shaped defects. Concomitant with ripening, extended-defect related traps with activation energies of 0.52 and 0.84 eV were observed, and regarded as the cause of the significant worsening of the optical and electrical properties in high coverage structures. Their relationship with the observed dislocations is discussed.