A comprehensive characterization of End-of-Life mobile phones for secondary material resources identification.

In this paper a full recognition of the different materials and valuable metals constituting mobile phones was performed. To this aim, a sample of 20 end-of-life devices has been dismantled and quantitative and qualitative chemical composition of the individual components was determined. From dismantling operations, it was found that plastics, metals, electronic components, batteries and displays account for 33%, 11%, 23%, 24% and 9% respectively, as a weighted average. Plastic parts of each item were analyzed by spectroscopy and then classified according to the plastic polymer type; it was found that polymeric components of mobile phones were made of five polymers: acrylonitrile-butadienestyrene, polycarbonate, polyurethane, polymethylmethacrylate and silicone. Electronic parts were leached by a twofold aqua regia treatment and the metal composition was determined: 15 elements were identified with concentration >0.2%. On the basis of these results, some considerations about the recycling context of end-of-life mobile phones were performed.

Materials recovery from waste liquid crystal displays: A focus on indium.

In the present work the recovery of indium and of the polarizing film from waste liquid crystal displays was experimentally investigated in the laboratory. First of all, the polarizing film was removed by employing a number of different techniques, including thermal and chemical treatments. Leaching of indium was then performed with HCl 6N, which allowed solubilisation of approximately 90% In (i.e. 260 mg In per kg of glass) at room temperature, without shredding. Indium recovery from the aqueous phase was then investigated through solvent extraction with polyethylene glycol (PEG)-based aqueous biphasic systems. Indium extraction tests through the PEG-ammonium sulphate-water system were conducted as a function of PEG concentration, salt concentration and molecular weight of PEG, using 1,10 phenanthroline as a ligand. The experimental results demonstrated that indium partitioning between the bottom (salt-rich) and the top (PEG-rich) phase is quite independent on the composition of the system, since 80-95% indium is extracted in the bottom phase and 5-20% in the top phase; it was also found that when PEG concentration is increased, the ratio between the bottom and the upper phase volumes decreases, resulting in an increase of indium concentration in the bottom phase (at [PEG]=25% w/w, indium concentration in the bottom phase is ∼30% higher than the initial concentration before the extraction).

Transcranial direct current stimulation enhances sucking of a liquid bolus in healthy humans.

BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive technique used for modulating cortical excitability in vivo in humans. Here we evaluated the effect of tDCS on behavioral and electrophysiological aspects of physiological sucking and swallowing. METHODS: Twelve healthy subjects underwent three tDCS sessions (anodal, cathodal and sham stimulation) on separate days in a double-blind randomized order. The active electrode was placed over the right swallowing motor cortex. Repeated sucking and swallowing acts were performed at baseline and at 15 and 60 min after each tDCS session and the mean liquid bolus volume ingested at each time point was measured. We also calculated average values of the following electrophysiological parameters: 1) area and 2) duration of the rectified EMG signal from the suprahyoid/submental muscles related to the sucking and swallowing phases; 3) EMG peak amplitude for the sucking and swallowing phases; 4) area and peak amplitude of the laryngeal-pharyngeal mechanogram; 5) oropharyngeal delay. RESULTS: The volume of the ingested bolus significantly increased (by an average of about 30% compared with the baseline value) both at 15 and at 60 min after the end of anodal tDCS. The electrophysiological evaluation after anodal tDCS showed a significant increase in area and duration of the sucking phase-related EMG signal. CONCLUSIONS: Anodal tDCS leads to stronger sucking of a liquid bolus in healthy subjects, likely by increasing recruitment of cortical areas of the swallowing network. This finding might open up interesting perspectives for the treatment of patients suffering from dysphagia due to various pathological conditions.