The fabrication of enzyme-based biosensors has received much attention for their selectivity and sensitivity. In particular, laccase-based biosensors have attracted a lot of interest for their capacity to detect highly toxic molecules in the environment, becoming essential tools in the fields of white biotechnology and green chemistry. The manufacturing of a new, metal-free, laccase-based biosensor with unprecedented reuse and storage capabilities has been achieved in this work through the application of the electrospray deposition (ESD) methodology as the enzyme immobilization technique. Electrospray ionization (ESI) has been used for ambient soft-landing of laccase enzymes on a carbon substrate, employing sustainable chemistry. This study shows how the ESD technique can be successfully exploited for the fabrication of a new promising environment-friendly electrochemical amperometric laccase-based biosensor, with storage capability up to two months without any particular care and reuse performance up to 63 measurements on the same electrode just prepared and 20 measurements on the one-year-old electrode subjected to redeposition. The laccase-based biosensor has been tested for catechol detection in the linear range 2-100 μM, with a limit of detection of 1.7 μM, without interference from chrome, cadmium, arsenic, and zinc and without any memory effects.

This paper presents the results of measurements performed on α-quartz subjected to shear stress in dry conditions, to understand the relationship between the shear intensity and the resulting physical and chemical effects. If a shear stress of intensity higher than 100 MPa is applied continuously to alpha quartz crystals, they will tend to lose their crystallinity, progressively reduce their friction coefficient (Cof) and change into a low-order material, apparently amorphous under X-ray diffraction, but with a structure different from silica glass. Raman and Pair Distribution Function analyses suggested a structure like cristobalite, a silica polymorph well-known for its auxetic behavior, i.e., having a negative Poisson ratio. This elastic parameter pre-eminently controls the friction coefficient of the material and, if it is negative, the Cof lowering. As a result, the increase in low crystallinity cristobalite is sufficientto explain the lowering of the quartz friction coefficient up to values able to contribute, in principle, to the triggering processes of active faults. This allows hypothesizing a slip induction mechanism that does not include the need to have the interposition of layers of hydrated silica, as invoked by many authors, to justify the low friction coefficients that are achieved in shear stress tests on rocks abundant in quartz.

Shear tests on quartz rocks and single quartz crystals have been conducted to understand the possible relationship between the intensity of detectable stress in fault areas and the energy released in the form of electromagnetic waves in the range 30 KHz-1 MHz (LF–MF). For these tests, a new type of piston-cylinder has been developed, instrumented to collect the electromagnetic signals generated by the quartz during shear stress tests and that allows energy measurements on electromagnetic emissions (EMR) to be performed. The data obtained indicate that shear-stressed quartz crystals can generate electromagnetic emissions in the LF–MF range. These emissions represent a tiny fraction of the total energy dissipated in the fracturing process. The spectrum of radio emissions consists of continuous radiation and overlapping peaks. For the first time, a characteristic migration of peak frequencies was observed, proportional to the evolution of the fracturing process. In particular, the continuous recording of the radio emission spectra shows a migration of the peaks toward higher frequencies, as stress continues over time and smaller and larger fractures form. This migration could be used to distinguish possible natural signals emitted by quartz in tectonically active environments from possible signals of other geophysical and possibly anthropogenic origin.

This study assesses the correlations between the intensity of stress undergone by crystals and the morphological characteristics of particles and fracturing products. The effects of the fractures on the microstructure of quartz are also studied. Alpha quartz, subjected to shear stress, is quickly crushed according to a fracturing sequence, with a total fracture length that is correlated to the stress rate. The shear stress generates a sequence of macro and microstructural events, in particular localized melting phenomena, never highlighted before on quartz and the formation of different polymorphs, such as cristobalite and tridymite together with amorphous silica.

A smart synthesis strategy exploiting the use of crystalline precursor salts, which until now has only been applied to the FePt system, was here extended to other binary alloys (CoPt, NiPt) with the aim of demonstrating the high potential of such a method and formulating a comprehensive explanation of the underlying process. Indeed, by exploiting the natural order of M(H2O)(6)PtCl6 (M = Fe, Co, Ni) crystalline precursor salts, consisting of M and Pt atoms on alternating planes that mimic the atomic arrangement of the L1(0) structure, highly ordered MPt alloy nanoparticles were obtained at lower processing temperatures and shorter reaction times than ordinary thermal processes, thus demonstrating the effectiveness and versatility of such an approach for the synthesis of L1(0) alloys. Comparing the results from the three different systems allowed a better comprehension of the underlying process, which involves the simultaneous occurring of the salt decomposition and the L1(0) ordering process. Indeed, differently to all the other existing approaches where thermal treatments are exploited to induce the disorder/order transition, the proposed strategy, which here we call Pre-ordered Precursor Reduction, is based on the opposite paradigm that is the preservation during the thermo-chemical treatment of the chemical order provided by the crystal. Thus, by properly choosing the starting salt, the proposed method can be used to synthesize a wide class of alloys, including those systems whose ordering formation is limited by kinetic and thermodynamic constraints. (C) 2020 Elsevier B.V. All rights reserved.

The reduction of CO2 emission from cement industry represents a priority task in the roadmap defined for the year 2020 by the European Union (EU) Commission for a resource efficient Europe. Several research projects have been undertaken aimed at developing non-hazardous materials as partial substitute of clinker in cement formulations, but also new, low-carbon, cements fully replacing clinker. Among the new cementing materials, Si-Al geopolymers seem the most promising, in terms of CO2 emission and mechanical and thermal properties. In this chapter, mechanochemical processing of kaolin clays to produce metakaolin (MKA) for the synthesis of Si-Al geopolymers is proposed as an alternative process to replace thermal treatments performed at 650-850 degrees C. Results obtained show that the mechano-chemical process is also suitable to make low cost blended Si-Al geopolymers where 40% of MKA is replaced by mechano-chemically activated volcanic tuffs. The compatibility of mechano-chemistry with industrial production was investigated by building a prototype milling system that was tested in a small industrial facility producing zeolites from industrial wastes. The degree of automation allowed the prototype to work unattended for 10 months. Based on the results obtained from these tests, a milling system for a full scale production of mechano-chemically activated rock materials was designed, and its performances analysed.

This work describes how a ring mill is used as a friction coefficient analysis system for granular materials during grinding. This assessment method was mainly created to analyse energy consumption in comminution processes in friction mills. A ring mills consists of a cylindrical jar containing the grinding masses as coaxial cylinders and rings, made from high strength materials, moved by an oscillating movement caused by eccentric masses arranged on the mill motor axis. Inside the jar the masses rotated by the jar's eccentric oscillation rotate freely, at a speed that depends on the friction between the grinding bodies and the jar's inner surfaces. The work checked how the grinding masses rotate, the mechanism causing coupling and the relations between these movements and the friction coefficient. With this model it is possible to measure grinding energy consumed instant by instant and the energy lost through heat and average pressure generated by the thrust of the grinding masses; and, lastly, the friction coefficient between the mass and the material interposed.

The generation and emission of particulate matter from abrasion industry are subjects of the pollution monitoring by multidisciplinary study involving earth sciences and engineering disciplines. This work investigates the correlation between textural properties of in situ rock with class size distribution and morphology of particles generated after rock comminution and particles emitted in the air. A special comminution-dust sampling architecture was realised. The combined use of scanning electron microscopy and particle size analyser was considered in performing digital image analysis on both crushed products and airborne particles collected onto membrane filters. The results show that the size and morphology of crushed particles are linked to the petrographic rock properties. In particular, particles with fibrous morphology are prominent in rocks showing foliated textures where elongated minerals occurred, with implication for asbestos-bearing rocks. For what concerns the airborne particles, the results show that their aerodynamic diameters are independent of the crusher operating conditions. External parameters probably intervene in the distribution of the airborne particles emission, including the dynamic air fluxes, or environmental conditions. By applying mathematical models, the morphology and size range of airborne particles following the comminution processes can be predicted, and results has implication for pollutants contamination due to particulate matters emitted by crush stone industry.

The aim of this work is the assessment of the possibility to produce geopolymeric materials for the specific use in the field of consolidation of stone materials or as restoration mortars, through mechanochemical activation of two solid precursors, quartz and kaolin. These starting materials were modified by grinding at different times and then the degree of reactivity of the obtained products was verified by studying the changes induced by the mechanical treatment on the crystalline structure and by determining the specific surface. Moreover the solubility and kind of alkaline solutions classically used for the production of geopolymeric materials (NaOH and KOH) was investigated together with other aqueous solutions at variable pH. The mechano-chemical activation process can achieve the result to reduce the use of alkaline solutions as activators of the starting raw materials in the production of consolidating solution for monument stone materials and to utilise natural materials in the production of restoration mortars compatible with the substrates to be restored.

The type and quality of the information provided by the direct analysis of volcanic tuffs by H-1, Si-29, and Al-22 NMR were investigated. At this aim, five tuffs, characterized by different origin, bonding mechanism, and clast composition, were used as test materials. Results consistent with the different nature of the tuff matrix and mineral composition were obtained. While the relative content of Al in the crystal and amorphous phase was determined by Al-27 MAS and 3Q MAS NMR, the prevalent glassy or zeolitic nature of the matrix was assessed by Si-29 and H-1 MAS NMR. Zeolites present at levels as low as 15% w/w were detected by Si-29 MAS NMR, and in some tuffs, identification of their framework type was performed together with the determination of the Si/Al ratio and, for the first time, of their configurational entropy. Data obtained were coherent with those provided by X-ray fluorescence (XRF), X-ray powder diffraction (XPRD), thermogravimetric analysis (TGA), differential thermal gravimetry (DTG), cation exchange capacity (CRC) determinations, and scanning electron microscopy, used in both backscattering imaging mode (SEM) and for elemental analysis (SEM-EDS). Results show that, under favorable conditions, solid state NMR techniques can provide a comprehensive view of the chemical and physicochemical behavior of a tuff. A combined use of these techniques is suitable for characterization of tuffs on a routine basis, and can be particularly useful to decide if a material is suitable for industrial applications.

The geochemical and engineering geological properties of the tuffs used in the rock‐cut cliff tombs of the Etruscan necropolis of Norchia were investigated to evaluate their susceptibility to different weathering agents and confirm their origin. For the first time, materials were characterized by X‐ray powder diffraction (XRD), Fourier‐transform infrared spectroscopy (FT–IR), thermogravimetric analyses (TGA, DGA and DTG), scanning electron microscopy (SEM–EDS) and energy‐dispersive X‐ray fluorescence (ED–XRF), and their different origins confirmed. Tests of material properties indicate that both tuffs are poorly durable, but one of them is less susceptible to weathering. Although tombs made with the more resistant material show limited surface weathering, they undergo severe structural damage because of stress release and plant root infiltration. This, combined with the microclimatic conditions established inside river canyons, can trigger rock falls, leading ultimately to the complete destruction of these tombs.

The identified emissions of abiogenic carbon dioxide, carbon monoxide and methane are generally attributed to volcanic activity or to geochemical processes associated with thermometamorphic effects. In this paper we show another possible abiogenic source of emission, induced by mechanical, and not thermal, stresses. We investigated the mechanochemical production of carbon dioxide and methane when friction is applied to marly-type rock and studied the mechanisms determining the strong CO2 and CH4 emissions observed. A ring mill was used to apply friction and oriented pressure upon a synthetic calcite-clay mixture of varying proportions. We found that the CO2 and CH4 release versus the grinding action has a non-linear trend reflecting the behaviour of decreasing crystallinity, which indicates a close link between crystallinity and gas production. For the CO2 emission, we propose a release mechanism connected with the friction-induced fractures and the increase in structural disorders induced by creep in the lattice. The CH4 emission could be explained by a Sabatier reaction in which CO2 and hydrogen are involved to form CH4 and water.

Field observations coupled with experimental results show that CO2 can be produced by mechanical energy applied to carbonate rocks becoming an unexpected additional gas source besides that degassed from the mantle or produced by thermometamorphism. The evidence that a large amount of carbon dioxide associated with radiogenic-type helium (R/Ra as low as 0.01–0.08) is released through continental areas, denotes the absence of a contribution from the mantle or from mantle-derived fluids. Data collected during the seismic crisis which struck the Central Apennines in 1997–98 have shown an enhanced CO2 flux not associated with the presence of mantle or thermometamorphic-derived fluids. On the other hand, new experimental results highlight the possibility of producing CO2 by mechanical energy that acts on the calcite crystalline lattice. While the CO2 released over the geothermal areas (e.g., Larderello Geothermal Field) is obviously derived by mantle-derived activities, this is not the case of the huge amount of CO2 released over the seismically active areas where the presence mantle-derived products is ruled out. We propose that mechanical energy, e.g., released during seismic events, microseismicity or creeping processes is a possible additional energy source able to produce CO2 and thus could explain the presence of CO2 degassing over tectonic areas where the influence of the mantle is low.

The paper provides a review of the studies performed, starting from the 1970 up to today by Italian National Council's Mineral Processing Institute, to develop application for the use of chelating reagents in the flotation of metallic minerals.A summary is given of the various phases through which the studies progressed, starting by employing commercial reagents and then moving on to the synthesis of new long-chain chelate collectors for the flotation of sulphide and oxidized Pb, Zn, and Cu minerals.In particular a description is presented of the thermodynamic and structural criteria to be followed in designing and synthesizing chelate-type collectors with optimal structure for a given metallic mineral.A theoretical method has been developed for choosing chelating groups that exert selective action on one metallic mineral rather than others. The theoretical approach is based on thermodynamic data of the chemical equilibria in solution.Moreover, the flotation results obtained in the flotation of oxidized and mixed Zn-Pb ores, by using chelating reagents with a mixed aliphatic aromatic structure, provided interesting pointers for designing the non-polar portion. The structural criteria identified via these studies were interpreted on the basis of chemical and steric considerations.Recently, the thermodynamic approach was adopted to identify selective reagents for the removal of minor elements and for the separation of copper from zinc in the xanthate flotation of complex sulphide ores. (C) 2007 Elsevier Ltd. All rights reserved.

The surface microchemical structure of high tin leaded bronze Roman mirrors has been studied by means of scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and optical microscopy (OM) techniques. The results allowed understanding of the origin of their high chemical stability and silvery-lustrous appearance. Indeed, some areas of the selected Roman mirrors are still characterised by a highly reflective and silver coloured surface even though they have been buried in the soil for about 2000 years. The micro-chemical results obtained from these areas have revealed that the mirror surface was tin enriched via inverse-segregation phenomenon by tailoring the cooling parameters. Furthermore, the presence of tin could be likely enhanced via cycles of oxidation and selective copper corrosion processes, thus resulting in a tin surface enrichment as a semi-transparent amorphous-like tin oxide (SnO(2)) film, as well as a copper depletion at the outer surfaces.

Non-destructive testing methods are very important tools for conservators and art historians to obtain valuable information about works of art without causing any or even local damage to them. Two successful case studies showing the noticeable potentialities of two analytical portable instruments employed in the characterisation of tangible cultural heritage are shown. The first example concerns the chemical characterisation via an X-ray fluorescence (XRF) portable instrument of the red decorative pigment and of the stone surface of the Capestrano Warrior (Archaeological Museum of Chieti, Italy), which is considered the most important Italic stone statue found in Italy. The second concerns the use of a portable electrochemical impedance spectroscopy (EIS) measurement system for the characterisation of the protective effectiveness of the paints on the railing of Palazzo Reale in Torino, Italy.

P.30.01.1 Poster Session: 30 August, Board: 191 P.30.01.3 Poster Session: 27 August, Board: 209 Acta Cryst. (2005). A61, C496 Acta Cryst. (2005). A61, C496 Surface: A Micro Instrument for in situ XRD-XRF and Optical Measurements Antimony Oxides: the Pyrochlore-type Structure Revisited Maria-Ondina Figueiredo Paolo Plescia, Gabriel M. Ingo, Andrea Bianco , Crystallography and Mineralogy Centre, IICT, & CENIMAT, New Univ. Lisbon, 2829-516 Caparica, Portugal. E-mail: crysmin@clix.pt , Alessandro Biasini 1 , ISMN-CNR, National Research Council of Italy Institute for the Study of Nanostructured Materials, Rome Italy. Assing Research Center, Rome Italy. E-mail: paolo.plescia@ismn.cnr.it Antimony oxides display a variety of structural arrangements with different stoichiometries resulting from two stable speciations for Sb ions. They commonly occur as minerals with well known crystal structure, but there are still questions regarding stibiconite a very rare yellow mineral with pyrochlore-type structure and approximate formula Sb The "SURFACE MONITOR" instrument is an innovative and integrated portable XRD-XRF apparatus combined with a reflectance spectro-photometrical system. The instrument was designed by ISMNCNR and Assing in the frawork of an European project (EUREKAEurocare) “Surface Monitor”, aimed to develop a portable system of multispectral analysis for the not destructive and not invasive characterisation of archaeological artefacts. Concerning the XRD analysis, the innovative design of the SURFACE MONITOR equipments allows to carry out the characterisation by using a ThetaTheta configuration from –10 to 140° 2 . XRD analysis can be also carried out in angular scan and in energy scan modality. The data collected by the detector are elaborated in an innovative 3D mode, indeed, for each step, the XRF spectrum is first stored and then all the fluorescence spectra are represented in a three-dimensional mode, by plotting the energy on the abscissas, the scan angle on ordinates in a horizontal plane and the measured intensity in the vertical plane (Z coordinates). By plotting the results in this mode, the user can friendly decide "to cut" the XRD spectrum to the wavelength of more interest, within the used energetic range in the experiment and to filter the scattering that reduces the signal-to-noise ratio. According to this new approach, the XRD spectrum is obtained not to as a single window of energy, but using all the available energies and therefore it turns out extremely more resolved, also using lowest powers. In order to validate this new instrument a large scale characterisation of metal archaeological artefacts has been carried out also for gaining deep insight into the micro-chemical structure of the stratified corrosion layers and of the bulk metallurgical features. This innovative apparatus and approach has evidenced that SURFACE MONITOR with its optical, XRD and XRD facilities have significant potential in studies of the corrosion products of archaeological silver and copper objects for their stabilisation and conservation. 3O6(OH) [1]. Great interest has been focused on synthetics because of antimony speciation in relation to color and crystal structure [2], and important ion exchange properties of Sb-pyrochlores were recently pointed out [3]. When studying yellow glazes from majolica-type tiles using X-ray absorption spectroscopy at the Sb K-edge [4], the possibility of an Sbpyrochlore being the final responsible for the actual coloring was advanced, despite antimony being added during the manufacture process as bindheimite, Sb

This paper investigates the possible role of mechanochemical CO2 production due to stimulation from the action of friction on calcite. This experimentation has two objectives: firstly, to obtain information on the effect of the mechanical disassociation of carbon dioxide from the carbonates and, secondly, to simulate the conditions that may arise during a tectonic action.The action of disassociation has been observed on pure calcium carbonate from analyses ground at different times in a ring-roller mill. The ring-roller mill is a grinding system that mainly works through friction and, to a lesser extent, by non-hydrostatic compression.It has been observed that the grinding action determines an abundant release of carbon dioxide, with a non-linear trend that emulates the trend in the decrease in crystallinity. This indicates a close connection between crystallinity and the dissociation of carbonate. The Authors hypothesize a carbon dioxide release mechanism linked to the factures induced by the friction and the increase in the structural disorder induced in the lattice by the plastic sliding. This mechanism could play an important role in the natural release of CO2, along with the other carbon dioxide sources that are already known of.

Numerous industrial and experimental facilities have been set up, particularly in the last ten years, as a result of studies and researches on treating asbestos-containing waste (ACW) to stabilise it and to enable its reuse. Some of the stabilisation processes reduce the hazards of ACW by imprisoning in a cement or resonoid matrix. Other processes modify the fibrous structure of asbestos and transform it into an inert substance. One such inactivation process is mechanochemical transformation. This new technology is extremely interesting both economically and industrially, especially in view of the European Directive 1999/3/CE of 24/4/99, which provides for the obligatory treatment of all types of waste material before its disposal.

Asbestos is a natural mineral fibre which has been known and utilized commercially for about a century. From the forties, it was employed on an ever-increasing scale throughout the mechanical engineering, building, paper-making and plastics sectors, to name but a few. This paper details the steps taken firstly to ascertain the thermal behaviour of such materials as may be encountered in day-to-day practice and secondly to examine the influence of the main process parameters on the preliminary design of gas - or fuel-oil-fired rotary kilns of the kind used for waste treatment.