Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.
The growing production and use of electric and electronic components has led to higher rates of metal consumption and waste generation. To solve this double criticality, the old linear management method (in which a product becomes waste to dispose), has evolved towards a circular approach. Printed circuit boards (PCBs) are the brains of many electronic devices. At the end of their life, this equipment represents a valuable scrap for the content of base metals such as Cu and Zn (25 and 2 wt %, respectively) and precious metals such as Au, Ag, and Pd (250, 1000, and 110 ppm, respectively). Recently, biotechnological approaches have gained increasing prominence in PCB exploitation since they can be more cost-efficient and environmentally friendly than the chemical techniques. In this context, the present paper describes a sustainable process which uses the fungal strain Aspergillus niger for Cu and Zn extraction from PCBs. The best conditions identified were PCB addition after 14 days, Fe3+ as oxidant agent, and a pulp density of 2.5% (w/v). Extraction efficiencies of 60% and 40% for Cu and Zn, respectively, were achieved after 21 days of fermentation. The ecodesign of the process was further enhanced by using milk whey as substrate for the fungal growth and the consequent citric acid production, which was selected as a bioleaching agent.
represented a fundamental step in the process for the establishment of the Association of Albanian Crystallographers (AAC, www.aaccryst.eu), which has now formally been founded and includes crystallographers from both Albania and Kosovo. The OpenLab followed the success of events organized in Albania during IYCr2014, namely the International Conference "New Frontiers of Nanomaterial Technologies for Applications in Biology and Medicine" and the 1st Workshop on Crystallography, held in conjunction with the 20th Congress of the Carpathian-Balkan Geological Association. At that time, the local community of crystallographers, with Dritan Siliqi (IC-CNR, Bari, Italy and member of AIC) and Michele Zema (IUCr and member of AIC) as facilitators, formed the OPAL (Organization for the Promotion of Crystallography in Albania) working group, which was then extended thanks to the participation of crystallographers from Kosovo, and finally converged into the AAC. The AAC is now a national member of the ECA and has applied for membership of the IUCr. Challenging the needs for crystallographic research, the AAC is supported by Ministry of Education and Science of Albania, the Polytechnic University of Tirana (Albania) and the University of Prishtina (Kosovo). With more than 30 senior researches active in crystallography interdisciplinary studies, part of departments or research institutes of universities in Albania and Kosovo, the network in the region is gaining more supports. The AAC wish to thank the IUCr, UNESCO, the Italian Crystallographic Association (AIC), the European Crystallographic Association (ECA) and the IC-CNR, Bari for their continuous support to all the activities held in Albania during the past years.
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