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Membrane materials with osmium nanoparticles have been recently reported for bulk membranes and supported composite membrane systems. In the present paper, a catalytic material based on osmium dispersed in n–decanol (nD) or n–dodecanol (nDD) is presented, which also works as an emulsion membrane. The hydrogenation of p–nitrophenol (PNP) is carried out in a reaction and separation column in which an emulsion in the acid-receiving phase is dispersed in an osmium nanodispersion in n–alcohols. The variables of the PNP conversion process and p–aminophenol (PAP) transport are as follows: the nature of the membrane alcohol, the flow regime, the pH difference between the source and receiving phases and the number of operating cycles. The conversion results are in all cases better for nD than nDD. The counter-current flow regime is superior to the co-current flow. Increasing the pH difference between the source and receiving phases amplifies the process. The number of operating cycles is limited to five, after which the regeneration of the membrane dispersion is required. The apparent catalytic rate constant (kapp) of the new catalytic material based on the emulsion membrane with the nanodispersion of osmium nanoparticles (0.1 × 10−3 s−1 for n–dodecanol and 0.9 × 10−3 s−1 for n–decanol) is lower by an order of magnitude compared to those based on adsorption on catalysts from the platinum metal group. The advantage of the tested membrane catalytic material is that it extracts p–aminophenol in the acid-receiving phase. [ABSTRACT FROM AUTHOR]

The recovery and recycling of metals that generate toxic ions in the environment is of particular importance, especially when these are tungsten and, in particular, thorium. The radioactive element thorium has unexpectedly accessible domestic applications (filaments of light bulbs and electronic tubes, welding electrodes, and working alloys containing aluminum and magnesium), which lead to its appearance in electrical and electronic waste from municipal waste management platforms. The current paper proposes the simultaneous recovery of waste containing tungsten and thorium from welding electrodes. Simultaneous recovery is achieved by applying a hybrid membrane electrolysis technology coupled with nanofiltration. An electrolysis cell with sulphonated polyether–ether–ketone membranes (sPEEK) and a nanofiltration module with chitosan–polypropylene membranes (C–PHF–M) are used to carry out the hybrid process. The analysis of welding electrodes led to a composition of W (tungsten) 89.4%; Th 7.1%; O2 2.5%; and Al 1.1%. Thus, the parameters of the electrolysis process were chosen according to the speciation of the three metals suggested by the superimposed Pourbaix diagrams. At a constant potential of 20.0 V and an electrolysis current of 1.0 A, the pH is varied and the possible composition of the solution in the anodic workspace is analyzed. Favorable conditions for both electrolysis and nanofiltration were obtained at pH from 6 to 9, when the soluble tungstate ion, the aluminum hydroxide, and solid thorium dioxide were formed. Through the first nanofiltration, the tungstate ion is obtained in the permeate, and thorium dioxide and aluminum hydroxide in the concentrate. By adding a pH 13 solution over the two precipitates, the aluminum is solubilized as sodium aluminate, which will be found after the second nanofiltration in the permeate, with the thorium dioxide remaining integrally (within an error of ±0.1 ppm) on the C–PHF–M membrane. [ABSTRACT FROM AUTHOR]

Although batteries containing heavy metals and toxic chemicals, including lead and cadmium, are supposed to be selectively collected, they still end up on municipal waste processing platforms. The separation of cadmium and lead ions is a problem that is circumscribed to the development of urban mining. This paper presents the recuperative separation of lead and cadmium ions by a composite membrane based on chitosan (Chi), sulfonated ethylene-propylene-diene terpolymer (sEPDM), and polypropylene hollow fiber (PPyHF). The performances of selected membranes are presented comparatively, both from the point of view of the morpho-structural characteristics, as well as of the performances in the target ion separation process, with recently reported results obtained with composite membranes based on chitosan. [ABSTRACT FROM AUTHOR]

This paper aims construct a machine learning model to evaluate the performance of the learning environment. The learning environment is mainly focused on spatial organization. Rooted in the primary relationship between man and space, the learning was found to be important in different directions within the active school; the environment in which a person lives affects its conception about the ideal. The place where a person lives determines its ideas about how a physical environment should be structured, leading to a certain mental model. Various possible models are investigated on a dataset obtained following a detailed survey in a learning institution. The results offer insight into the contributing factors to learning performance, as well as provide a future baseline for the introduction of classroom robotics. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a mobile robot with the ability to avoid obstacles using fuzzy logic control. The robot has to be capable of detecting and avoiding obstacles around it. Fuzzy logic control has been chosen because it is a problem-solving control system methodology which incorporates a simple rule-based approach to solving control problem rather than attempting to model a system mathematically. The fuzzy logic decision system was implemented on a robotic platform made up of four engines, each with a transmission box and attached wheels, a microcontroller ATMega328 on an Arduino UNO board and two sensors for obstacle detection. [ABSTRACT FROM AUTHOR]

This paper presents a transport and recovery of silver ions through bulk liquid membranes based on n–decanol using as carriers 10–undecylenic acid and 10–undecylenyl alcohol. The transport of silver ions across membranes has been studied in the presence of two types of magnetic oxide nanoparticles obtained by the electrochemical method with iron electrodes in the electrolyte with and without silver ions, which act as promoters of turbulence in the membrane. Separation of silver ions by bulk liquid membranes using 10–undecylenic acid and 10–undecylenyl alcohol as carriers were performed by comparison with lead ions. The configuration of the separation module has been specially designed for the chosen separation process. Convective-generating magnetic nanoparticles were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy dispersive spectroscopy analysis (EDAX), Fourier Transform InfraRed (FTIR) spectroscopy, thermal gravimetric analysis (TGA), differential scanning calorimetry and magnetization. The process performance (flux and selectivity) was tested were tested for silver ion transport and separation through n–decanol liquid membranes with selected carriers. Under the conditions of the optimized experimental results (pH = 7 of the source phase, pH = 1 of the receiving phase, flow rate of 30 mL/min for the source phase and 9 mL/min for the receiving phase, 150 rot/min agitation of magnetic nanoparticles) separation efficiencies of silver ions of over 90% were obtained for the transport of undecenoic acid and about 80% for undecylenyl alcohol. [ABSTRACT FROM AUTHOR]

Composite membranes play a very important role in the separation, concentration, and purification processes, but especially in membrane reactors and membrane bioreactors. The development of composite membranes has gained momentum especially through the involvement of various nanoparticles, polymeric, oxide, or metal, that have contributed to increasing their reactivity and selectivity. This paper presents the preparation and characterization of an active metal nanoparticle-support polymer type composite membrane, based on osmium nanoparticles obtained in situ on a polypropylene hollow fiber membrane. Osmium nanoparticles are generated from a solution of osmium tetroxide in tert-butyl alcohol by reduction with molecular hydrogen in a contactor with a polypropylene membrane. The composite osmium-polypropylene hollow fiber obtained membranes (Os-PPM) were characterized from the morphological and structural points of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX), X-ray diffraction analysis (XRD), Fourier transform Infrared (FTIR) spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry (TGA, DSC). The process performance was tested in a redox process of p-nitrophenol and 10-undecylenic (10-undecenoic) acid, as a target substance of biological or biomedical interest, in solutions of lower aliphatic alcohols in a membrane contactor with a prepared composite membrane. The characteristics of osmium nanoparticles-polypropylene hollow fiber membranes open the way to biological and biotechnological applications. These membranes do not contaminate the working environment, operate at relatively low temperatures, provide a large contact area between reactants, allow successive oxidation and reduction operations in the same module, and help to recover the reaction mass by ultrafiltration. The results obtained show that the osmium-polypropylene composite membrane allows the reduction of p-nitrophenol or the oxidation of 10-undecylenic acid, the conversion depending on the concentration in the lower aliphatic alcohol, the nature of the lower aliphatic alcohol, and the oxidant or reducing flow through the membrane contactor. [ABSTRACT FROM AUTHOR]

Membranes are associated with the efficient processes of separation, concentration and purification, but a very important aspect of them is the realization of a reaction process simultaneously with the separation process. From a practical point of view, chemical reactions have been introduced in most membrane systems: with on-liquid membranes, with inorganic membranes or with polymeric and/or composite membranes. This paper presents the obtaining of polymeric membranes containing metallic osmium obtained in situ. Cellulose acetate (CA), polysulfone (PSf) and polypropylene hollow fiber membranes (PPM) were used as support polymer membranes. The metallic osmium is obtained directly onto the considered membranes using a solution of osmium tetroxide (OsO4), dissolved in tert–butyl alcohol (t–Bu–OH) by reduction with molecular hydrogen. The composite osmium–polymer (Os–P)-obtained membranes were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy-dispersive spectroscopy analysis (EDAX), Fourier Transform Infra-Red (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The process performance was tested for reduction of 5–nitrobenzimidazole to 5–aminobenzimidazole with molecular hydrogen. The paper presents the main aspects of the possible mechanism of transformation of 5–nitrobenzimidazole to 5–aminobenzimidazole with hydrogen gas in the reaction system with osmium–polymer membrane (Os–P). [ABSTRACT FROM AUTHOR]

The membranes and membrane processes have succeeded in the transition from major technological and biomedical applications to domestic applications: water recycling in washing machines, recycling of used cooking oil, recovery of gasoline vapors in the pumping stations or enrichment of air with oxygen. In this paper, the neutralization of condensation water and the retention of aluminum from thermal power plants is studied using ethylene propylene diene monomer sulfonated (EPDM-S) membranes containing magnetic particles impregnated in a microporous propylene hollow fiber (I-PPM) matrix. The obtained membranes were characterized from the morphological and structural points of view, using scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX) and thermal gravimetric analyzer. The process performances (flow, selectivity) were studied using a variable magnetic field generated by electric coils. The results show the possibility of correcting the pH and removing aluminum ions from the condensation water of heating plants, during a winter period, without the intervention of any operator for the maintenance of the process. The pH was raised from an acidic one (2–4), to a slightly basic one (8–8.5), and the concentration of aluminum ions was lowered to the level allowed for discharge. Magnetic convection of the permeation module improves the pH correction process, but especially prevents the deposition of aluminum hydroxide on hollow fibers membranes. [ABSTRACT FROM AUTHOR]

This paper describes the steps involved in obtaining a set of relevant data sources and the accompanying method using software-based sensors to detect anomalous behavior in modern smartphones based on machine-learning classifiers. Three classes of models are investigated for classification: logistic regressions, shallow neural nets, and support vector machines. The paper details the design, implementation, and comparative evaluation of all three classes. If necessary, the approach could be extended to other computing devices, if appropriate changes were made to the software infrastructure, based upon mandatory capabilities of the underlying hardware. [ABSTRACT FROM AUTHOR]