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In clinical treatments of a class of tumors, e.g. skin tumors, the drug uptake of tumor tissue is helped by means of a pulsed electric field, which permeabilizes the cell membranes. This technique, which is called electroporation, exploits the conductivity of the tissues: however, the tumor tissue could be characterized by inhomogeneous areas, eventually causing a non-uniform distribution of current. In this paper, the authors propose a field model to predict the effect of tissue inhomogeneity, which can affect the current density distribution. In particular, finite-element simulations, considering non-linear conductivity against field relationship, are developed. Measurements on a set of samples subject to controlled inhomogeneity make it possible to assess the numerical model in view of identifying the equivalent resistance between pairs of electrodes.

In this paper, an innovative approach for the fast estimation of the mutual inductance between transmitting and receiving coils for Dynamic Wireless Power Transfer Systems (DWPTSs) is implemented. To this end, a Convolutional Neural Network (CNN) is used; an image representing the geometry of two coils that are partially misaligned is the input of the CNN, while the output is the corresponding inductance value. Finite Element Analyses are used for the computation of the inductance values needed for CNN training. This way, thanks to a fast and accurate inductance estimated by the CNN, it is possible to properly manage the power converter devoted to charge the battery, avoiding the wind up of its controller when it attempts to transfer power in poor coupling conditions. [ABSTRACT FROM AUTHOR]

Understanding how dust can ignite and explode in an industrial contest is an important and complex task, and much of the work around this is mainly performed via experimental measurements, in accordance to specific standards. However, those same properties are straightforwardly closely related to the nature of the experimental tests. Among these, the Minimum Ignition Energy (MIE) of a dust cloud, that is usually measured in a MIKE 3 apparatus, can be affected by several factors, as: delay time of the electric spark with respect to the dust-air dispersion formation inside the apparatus, dust concentration, humidity content, dust granulometry, etc. The delay time is one of the worst parameters to adjust, because the fluid-dynamics of the dust-air mixture inside the tube is not easily predictable. Within this work, a study on the characteristic times of all the relevant phenomena occurring within a MIKE 3 apparatus was done by means of slow-motion videos of the tests. Particularly, three different characteristic times were compared referring to a given sample of niacin dust: dust lifting and settling times, effective spark delay time (that is, the time at which the spark is visible) and combustion time (that is, the time at which the flame is visible). According to the results, the effective delay time is almost always quite different with respect to the theoretical one, influencing the effective concentration of dust between the electrodes and, finally, the possibility to have a flame ignition or not within the apparatus. This means that the value of the MIE parameter can be profoundly influenced by the effective delay. [ABSTRACT FROM AUTHOR]

In recent years, superficial chest wall recurrence from breast cancer can be effectively treated by means of electrochemotherapy, with the majority of patients achieving response to treatment. Nevertheless, tumor spread along superficial lymphatic vessels makes this peculiar type of tumor recurrence prone to involve large skin areas and difficult to treat. In these cases, electroporation with standard, small size needle electrodes can be time-consuming and produce an inhomogeneous coverage of the target area, ultimately resulting in patient under treatment.

Fine chemical compounds and so-called "specialties" are generally synthesized through batch or semicontinuous processes. This is largely because such syntheses often involve complex and highly exothermic reactions, to be performed in semi-batch reactors for safety and/or selectivity reasons. An effective way to reduce costs and improve the reproducibility of such batch processes is to transform them into their continuous counterparts to reduce volumes and investment costs, while increasing the inherent safety of the process thanks to fewer hold-ups. The “shift to continuous” allows to reduce both the overall process times, with a general decrease in operating costs, and the content of solvents used as thermal flywheels, thanks to the greater efficiency of the heat exchange systems. All these aspects are defined as process intensification. In this work, the intensification of the production process of N-(4-nitro, 2-phenoxyphenyl) methanesulfonamide (NIM) by nitration in glacial acetic acid of N-(2-phenoxyphenyl) methanesulfonamide (FAM) will be proposed. Starting from the original semi-batch recipe two different continuous configurations will be proposed: a series of tubular reactors and a series of continuous reactors with complete mixing, in both cases with intermediate injections. The solvent content (glacial acetic acid) has been drastically reduced (from 82.5% to 50% by weight) to increase the levels of environmental sustainability of the synthesis. The high exothermicity of the process and the extremely rapid reaction kinetics were two fundamental aspects which had to be considered in the transition to the continuous process of the new formulation with reduced solvent content. For this reason, an ad hoc procedure was developed which allows the semi-batch recipe to be transformed into a corresponding one conducted in a tubular reactor with continuous lateral injections; this reactor was then discretized in the two reactor configurations mentioned above. The results obtained have shown how it is possible to obtain the desired product with practically unitary conversions using: a) a series of 4 isoperibolic tubular reactors, each with 4 discrete lateral feeds; b) a series of 5 mixed reactors with discrete side feeds. In both cases, the correct distribution of both the flow rate fed between the reactors in series and the temperatures of the cooling fluid (defined on the basis of the procedure developed for the passage of the process from discontinuous to continuous) was decisive for obtaining the desired performance. The series of tubular reactors was found to be optimal from the point of view of thermal control of the process, confirming that a series of tubular reactors is to be preferred in terms of safety compared to its counterpart with mixed reactors. [ABSTRACT FROM AUTHOR]

In the framework of sustainability, proposing new technologies to improve the current linear economy system is one of the most challenging aspects for both academics and industries. In this context, the optimization of wastewater recovery and re-use are among the most crucial aspects to improve; in fact, contaminated waters come from a wide range of industries: cooking, refineries, food, pharmaceuticals, textile and agriculture. Heavy metals are among the most critical pollutants, being widely spread (especially in the textile sector) and difficult to remove. In this work, two different sets of Magnetic Nanostructured Adsorbents (MNAs) to clean wastewaters containing Chromium (III), Nickel (II) and Copper (II) ions were studied and compared. The first type of MNA was a 2-D nanosheet structure generated using iron (II/III) salts and sodium (or ammonium) hydroxide solution to decorate a dispersion of graphene oxide (GO) in water. The second type of adsorbent was a 3-D structure composed of GO-MNAs embedded in cross-linked alginate beads. Performed experiments (in a wide range of metal ions concentrations) showed very promising results in terms of removal efficiencies (almost complete abatement could be achieved using a proper amount of MNAs) with respect to all tested contaminants, highlighting better performances of the beads with respect to the corresponding 2-D structure. [ABSTRACT FROM AUTHOR]