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Superconducting properties of the Fe(Se,Te) system are directly related to its microstructure. However, in the framework of a not well assessed phase diagram, a large spread of chemico-physical and functional properties is reported for compounds characterized by similar overall chemical compositions. This is in particular observed in materials produced by melting routes, where chemical inhomogeneities and multiple phases are commonly obtained. Both composition and morphology of these inhomogeneities seem to play a role in the behaviour of the superconducting phases, pointing out the need to assess the dependence of phase composition and therefore of the material performance on the sample thermal history. In this work, the effect of different post-synthesis annealing treatments is studied. A melting route has been adopted to synthesize polycrystalline samples, subsequently subjected to thermal treatments at different temperatures. Morphology and microstructure were characterized by means of x-ray diffraction and microscopy techniques. The superconducting properties have been evaluated by means of electrical and magnetic measurements. It is observed how microstructure, chemical composition and morphology of the obtained products strictly depend on the annealing temperature. Moreover, a crucial role of the cooling step is evidenced: in fact, a rapid cooling procedure from high temperature leads to the formation of high temperature (Tconset > 19 K) superconducting phases, but the overall bulk superconducting performance is negatively affected. Other annealing treatments can promote instead an enhancement in the critical current at high fields with respect to pristine sample, suggesting that a careful engineering of a post-synthesis thermal step can represent a useful tool to optimize the material properties.

The synthesis of hydroxylammonium lead iodide NH3OHPbI3 was accomplished by means of the reaction between water solutions of HI and NH2OH with PbI2 in sulfolane in conjunction with either crystallization by CH2Cl2 vapor diffusion or sulfolane extraction with toluene. The appropriate choice of the solvent was found to be crucial in order to attain the desired material. The synthesized compound was extensively characterized by single crystal and powder X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, FT-IR spectroscopy, 1H-NMR spectroscopy, TG-DTA-QMS EGA (Evolved Gas Analysis), ESI-MS, and CHNS analysis. NH3OHPbI3 is an extremely reactive, deliquescent solid that easily oxidizes in air releasing iodine. Furthermore, it is the first reported perovskite to melt (m.p. around 80 °C) before decomposing exothermally at 103 °C. Such a chemical behavior, together with its optical absorption properties (i.e. yellow-colored perovskite), renders this material totally unsuitable for photovoltaic applications. The deliquescence of the material is to be ascribed to the strong hydrophilicity of hydroxylammonium ion. On the other hand, the relatively high Brønsted acidity of hydroxylammonium (pKa = 5.97) compared to other ammonium cations, promotes the reduction of atmospheric oxygen to water and the NH3OHPbI3 oxidation. The crystal structure, determined by single crystal X-ray diffraction with synchrotron radiation, is orthorhombic, but differs from the prototypal perovskite structure. Indeed it comprises infinite chains of face-sharing PbI6 octahedra along the c-axis direction with hydroxylammonium cations positioned between the columns, forming layers on the ac plane. The solvent intercalates easily between the layers. The crystal structure is apparently anomalous considering that the expected Goldschmidt's tolerance factor for the system (0.909) lies in the range of a stable prototypal perovskite structure. Therefore, the strong hydrogen bond forming tendency of hydroxylamine is likely to account for the apparent structural anomaly.

The influence of drying temperature on the starch crystallites and its impact on durum wheat pasta sensory properties is addressed in this work. In particular, spaghetti were produced by means of a pilot plant using 5 different drying temperature profiles. The sensory properties, as well as the cooking quality of pasta were assessed. X-ray powder diffraction was used for investigating changes in the crystallinity content of the samples. Starch crystallinity, size and density of the starch crystallites were determined from the analysis of the diffraction profiles. As expected, spaghetti sensory properties improved as the drying temperatures increased. In particular, attributes as resistance to break for uncooked samples and firmness, elasticity, bulkiness and stickiness for cooked samples, all benefit from drying temperature increase. The spaghetti cooking quality was also positively affected by the drying temperature increase. Diffraction analysis suggested that the improvement of sensory properties and cooking quality of pasta were directly related to the increase in density of both physical crosslink of starch granules and chemical crosslink of protein matrix. (C) 2016 Elsevier Ltd. All rights reserved.

The synthesis of hydroxylammonium lead iodide NH3OHPbI3 was accomplished by means of the reaction between water solutions of HI and NH2OH with PbI2 in sulfolane in conjunction with either crystallization by CH2Cl2 vapor diffusion or sulfolane extraction with toluene. The appropriate choice of the solvent was found to be crucial in order to attain the desired material. The synthesized compound was extensively characterized by single crystal and powder X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, FT-IR spectroscopy, 1H-NMR spectroscopy, TG-DTA-QMS EGA (Evolved Gas Analysis), ESI-MS, and CHNS analysis. NH3OHPbI3 is an extremely reactive, deliquescent solid that easily oxidizes in air releasing iodine. Furthermore, it is the first reported perovskite to melt (m.p. around 80 °C) before decomposing exothermally at 103 °C. Such a chemical behavior, together with its optical absorption properties (i.e. yellow-colored perovskite), renders this material totally unsuitable for photovoltaic applications. The deliquescence of the material is to be ascribed to the strong hydrophilicity of hydroxylammonium ion. On the other hand, the relatively high Bronsted acidity of hydroxylammonium (pKa = 5.97) compared to other ammonium cations, promotes the reduction of atmospheric oxygen to water and the NH3OHPbI3 oxidation. The crystal structure, determined by single crystal X-ray diffraction with synchrotron radiation, is orthorhombic, but differs from the prototypal perovskite structure. Indeed it comprises infinite chains of face-sharing PbI6 octahedra along the c-axis direction with hydroxylammonium cations positioned between the columns, forming layers on the ac plane. The solvent intercalates easily between the layers. The crystal structure is apparently anomalous considering that the expected Goldschmidt's tolerance factor for the system (0.909) lies in the range of a stable prototypal perovskite structure. Therefore, the strong hydrogen bond forming tendency of hydroxylamine is likely to account for the apparent structural anomaly.

The recent discovery of superconductivity in a metallic aromatic hydrocarbon, alkali-doped p-Terphenyl, has attracted considerable interest. The critical temperature Tc ranges from few to 123 K, the record for organic superconductors, due to uncontrolled competition of multiple phases and dopant concentration. In the proposed mechanism of Fano resonance in a superlattice of quantum wires with coexisting polarons and Fermi particles, the lattice properties play a key role. Here we report a study of the temperature evolution of the parent compound p-Terphenyl crystal structure proposed to be made of a self-assembled supramolecular network of nanoscale nanoribbons. Using temperature dependent synchrotron radiation x-ray diffraction we report the anisotropic thermal expansion in the ab plane, which supports the presence of a nanoscale network of one-dimensional nanoribbons running in the b-axis direction in the P21/a structure. Below the enantiotropic phase transition at 193 K the order parameter of the C-1 structure follows a power law behaviour with the critical exponent 0.34 and the thermal expansion of the a-axis and b-axis show major changes supporting the formation of a two-dimensional bonds network. The large temperature range of the orientation fluctuations in a double well potential of the central phenyl has been determined., Comment: Journal of Superconductivity Novel Magnetism , 15 pages, 4 figures

The mineralogy and crystal chemistry of apatites occurring in 14 ejecta of historical eruptions (1631 and 1872 A.D.) of the Somma-Vesuvius volcanic complex were investigated by a multi-methodological approach including polarized optical microscopy, scanning electron microscope, electron microprobe analysis in wavelength-dispersive mode, laser ablation inductively coupled plasma mass spectroscopy, and single-crystal X-ray diffraction. Five different groups of apatite, with different mineralogical and crystal-chemical features, were identified. Apatite crystals occur with well-developed hexagonal prismatic habit and, more rarely, with skeletal acicular forms. The crystals are yellow (type 1), transparent and colorless (type 2 and type 3), green (type 4) and aquamarine colored (type 5), with different paragenesis: macro-crystalline aggregates of clinopyroxenes, phlogopite, and apatite (type 1; type 4); clusters of apatite with micro-crystalline clinopyroxene, minerals of the cancrinite group, feldspars, and opaque minerals (type 2); aggregates of apatite, sellaite, wagnerite, gypsum, and phlogopite (type 3); aggregates of davyne, nepheline, mica group minerals, and apatite (type 5). Chemical analyses of apatites show variable amounts of Na, REE, Mg, Sr, and Fe replacing Ca, not negligible amounts of Si and S substituting P, and a significant substitution of Cl and OH instead of F. Five crystals representative of each apatite-type were studied by single-crystal X-ray diffraction. Their crystal structure was refined in the hexagonal P 63/ m space group. A significant variation of the unit-cell parameters with the composition was observed. A comparative crystal-chemical analysis between apatites from Somma-Vesuvius and those from other localities is carried out.

""The structural characterization of whiteite-(CaFeMg), a natural orthophosphate from Crosscut Creek, Yukon, Canada, with chemical composition (Ca0.86Na0.05)∑=0.91(Fe0.88Mn0.02)∑=0.90Mg2.17Al1.93(PO4)4(OH)2∙8H2O obtained by WDS-EMPA, was carried out by means of single crystal X-ray diffraction. The structure was solved in the P2\\\/a monoclinic space group, with the following unit cell constants: a = 14.8700(15), b = 6.9785(5), c = 9.9268(10) Å, beta = 110.110(1)°, V = 967.31(15) Å3. Struc-ture refinement lead to the crystal chemical formula (Ca0.95Na0.11)∑=1.06Fe0.90Mg2.01Al2.05(PO4)4(OH)1.99∙8.17H2O. Phosphorus atoms display tetrahedral (PO4) coordination, while magnesium, iron(II) and aluminum display regular octahedral coordination; calcium displays a complex CaO8 coordination. MgO2(H2O)4, FeO6, AlO4(OH)2, CaO8 poly-hedra and PO4 groups are arranged such as to form a three-dimensional framework via edge- and vertex-sharing ar-rangements. Strong O-H…O hydrogen bonds contribute to stabilize the array: such interactions were also investigated by means of Libowitzky formula (Libowitzky, 1999) appli-cation, owing to the results of IR spectroscopy.""

We report here the synthesis of the Z-3N(2-ethoxyphenyl)-2-N′(2-ethoxyphenyl)-imino-thiazolidin-4-one compound. The crystal structure is determined by X-ray diffraction. The compound crystallizes in the monoclinic system with the space group P21/n and cell parameters: a = 9.4094(10) A, b = 9.3066(10) A, c = 20.960(2) A, β = 99.0375(10)°, V = 1812.7(3) A3 and Z = 4. The structure is refined to final R = 0.05 for 2083 observed reflections. The molecule in the crystal exhibits the intermolecular hydrogen bonds of C–H…O, C–H…N, and C–H…S types. Ab initio calculations are also performed at Hartree–Fock (HF) and density functional theory (DFT) levels. The full HF and DFT geometry optimization is carried out using the 6-31G(d,p) basis set. The observed molecular structure is compared with that calculated by both HF and DFT methods. The optimized geometry of the titled compound is found to be consistent with the structure determined by X-ray diffraction.

Many materials have been tested as substrates and surface products. Typically ferrous (Carbon Steels and Stainless Steels) and non-ferrous (Al and Cu metals and its alloys) materials have been employed. Some epoxy, polyurethane, polyester and acrylic paints with different thickness and colour have been tested. Many types of surface rust and oxide on different bulk material have been undertaken to test. Similarly, some different types of oils and greases commonly used in industry to prevent oxidation, have been studied. Different types of laser sources have been employed: an axial fast flow, 1.5 kW CO2 c.w. and pulsed laser source emitting a 10.6 μm beam; and a portable Nd:YAG laser, Q-switchedand normal-mode source: 1st harmonic 1.064 μm (6 ns pulse duration), 2nd harmonic 532 nm (120 μs duration pulse, 1 J max per pulse) wavelengths, multi-articulated seven mirror beam guiding device, 20 Hz repetition rate. This provides shots with 600 mJ maximum energy per pulse and 100 MW peak power per pulse with very low beam divergence: 0.5 mrad at full angle.

Al2O3 seal ring faces were treated by KrF excimer laser irradiation. Surface characteristics induced by laser irradiation depend upon laser fluence, the number of laser pulses, the frequency and duration of the laser pulses, the rotation rate of the ring, and the processing atmosphere.

X-ray powder diffraction was combined, for the first time, with Nuclear Magnetic Resonance spectroscopy and direct infusion mass spectrometry to characterise fresh and brined grape leaves. Covariance analysis of data generated by the three techniques was performed with the aim to correlate information deriving from the solid part with those obtained for soluble metabolites. The results obtained indicate that crystalline components can be correlated to the metabolites contained in the grape leaves, paving the way to the use of X-ray diffraction analysis for food fingerprinting purposes. Moreover it was ascertained that, differently from most of the metabolites present in the fresh vine leaves, linolenic acid (an omega-3-fatty acid) and quercetin-3-O-glucuronide (a polyphenol metabolite) do not undergo sensible degradation during the brining process, which is used as preservative method for the grape leaves. (C) 2013 Elsevier Ltd. All rights reserved.

C27H36ClN2O9PS, monoclinic, C12/c1 (no. 15), a = 36.495(3) A?, b = 8.5574(4) A?, c = 20.487(4) A?, b = 101.18(2)°, V = 6276.8 A?3, Z = 8, Rgt(F) = 0.052, wRref(F2) = 0.125, T = 295 K.

Nonstoichiometric REEAl(2.07)(B(4)O(10))O(0.60) (REE = (La, Ce); Ce; Nd) dimetaborates have been crystallized and analyzed by means of single crystal X-ray diffraction. The compounds resulted to be isostructural within hexagonal space group P (6) over bar 2m (n. 189), with the following unit cell parameters: a = 4.6060(6) angstrom, c = 9.3510(8) angstrom and V = 171.81(3) angstrom(3) (La, Ce); a = 4.5960(6) angstrom; c = 9.3170(10) angstrom and V = 170.44(4) angstrom(3) (Ce); a = 4.5830(7) angstrom, c = 9.2810(14) angstrom and V = 168.82(4) angstrom(3) (Nd). The REE cations are surrounded by six oxygen atoms, making up a trigonal prismatic coordination; Al cation is surrounded by five oxygen atoms, resembling a square pyramidal coordination, while the BO(4) group displays tetrahedral arrangement. The three-dimensional framework can be described as a mica-like structure packed down crystallographic axis c, with layers of six-membered rings of B tetrahedra alternated by inter-layers REE cations and layers of Al polyhedra. A complex network of REE center dot center dot center dot O and Al center dot center dot center dot O interactions concur to stabilize the framework.

This experimental research work presents for the first time the results obtained by using a new non-conventional process, that is a cold and hot laser surface tratment on steels. The aim is to obtain Surface Hardening Structure by a sharp change in temperature obtained by employing a laser beam that passes on steel surfaces , having many tenths degrees below zero (≈ -196°C). The materials experimented have been some different Carbon Steels as Constructional ones (Fe 510 - Fe 360 B) and Medium and High Carbon content Steels ( C40-C70 ). The innovation of this new process consists havig to use a powerfull cooling medium - the liquid Nitrogen - into a Dewar recipient in which the steel has immersed for some minutes. The preliminary researches and tests have shown that, also on steels having a low content of Carbon, the Surface Hardness has significantly increased, so to reach values up to an increase of about 50% respect to the relate value measured on the base material.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

TiO2 film deposition by PAPLD with biased substrates is investigated into a wide range of laser fluence and oxygen pressure. It is established that plasma of the r.f. discharge excited inside PLD chamber strongly affects the films properties. TiO2 films deposited by PAPLD were found better than those produced by the conventional PLD with regard to their morphology, optical properties, and uniformity. So, at the high values of Knudsen number (lambda) /L < 1 with an r.f. power of 70 Watt, PAPLD markedly improves the TiO2 film stoichiometry for high laser fluence, and the deposition rate increases with it up to 2 A/s.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Silicon carbide ceramic seal rings are treated by KrF excimer laser irradiation. Surface characteristics, induced by lasertreatment, depend upon laser fluence, the number of laser pulses, their energy and frequency, the rotation rate of the ringand the processing atmosphere. It was ascertained that silicon carbide has to be processed under an inert atmosphere toavoid surface oxidation. Microstructural analyses of surface and cross section of the laser processed samples showed thatthe SiC surface is covered by a scale due to the melting/resolidification processes (at low fluence: 1 .8 J/cm2). At highfluence (7.5 J/cm2) there are no continuous scales on the surfaces; materials is removed by decomposition/vaporisation andthe ablation depth is linearly dependent on the number of pulses. Different surface morphologies (flat and rugged areas,deposits of debris and discontinuous thin remelted scales) are observed. The evolution of surface morphology and roughnessis discussed with reference to composition, microstructure and physical and optical properties of the ceramic material and tolaser processing parameters. Preliminary results on tribological behaviour ofthe treated seals are reported.Keywords: Silicon Carbide, SiC, seal ring, laser ablation, microstructure, roughness.

Industrial manufacturers produce many types of pressure gauges and transducers according to the applications, for gas or liquid, for high-medium and low pressure ranges. Nowadays the current production technology generally prefers to weld by micro TIG source the metallic corrugated membranes to the gauge or transducer bodies for the products, operating on the low pressure or medium pressure ranges. For the other ones, operating to high pressure range, generally the two components of the transducers are both threaded only and threaded and then circularly welded by micro TIG for the other higher range, till to 1000 bar. In this work the products, operating on the approximately equals 30 divided by 200 bar, are considered. These, when assembled on industrial plants, as an outcome of a non-correct operating sequence, give a 'shifted' electrical signal. This is due to a shift of the 'zero electrical signal' that unbalances the electrical bridge - thin layer sensor - that is the sensitive part of the product. Moreover, for the same problem, often some mechanical settlings of the transducer happen during the first pressure semi-components, with an increasing of the product manufacturing costs. In light of all this, the above referred, in this work the whole transducer has been re-designed according to the specific laser welding technology requirements. On the new product no threaded parts exist but only a circular laser welding with a full penetration depth about 2.5 divided by 3 mm high. Three different alloys have been tested according to the applications and the mechanical properties requested to the transducer. By using a 1.5 KW CO2 laser system many different working parameters have been evaluated for correlating laser parameters to the penetration depths, crown wides, interaction laser-materia times, mechanical and metallurgical properties. Moreover during the laser welding process the measurements of the maximum temperature, reached by the transducer top, has been read and recorded. At least some transducers, before the usual destructive testings, have been undertaken to many pressure test cycles to verify any pressure drops, the transducer sealing and the total quality of the new product.

Many materials as substrates and surface products have been tested. Typically ferrous (Carbon Steels and Stainless Steels) and non ferrous (Al and Cu metals and its alloys) ones have been employed. Some epoxy, polyurethane, polyester and acrylic paints in different thickness and color have been tested. Many types of the surface rust and oxide on different bulk material have been undertaken to test. Similarly some different types of oils and greases, usually used in industry against the oxidation, have been studied. Anyway many types of dirt, grit, calcareous one and so on, present on industrial components, have been laser cleaned without using solvents, acid baths and other ones. Different types of laser sources have been employed: an axial fast flow, 1.5 KW CO2 c.w. and pulsed laser source, emitting a 10.6 micrometers beam; a portable CO2 laser, c.w. (1 to 25 W) and pulsed (1 to 100 Hz and 400 ms max pulse duration) source, emitting a 10.6 micrometers beam with a multi-articulated seven mirrors guiding device and focussing head; a portable Nd-YAG laser, Q-switched and normal-mode source. 1st harmonic 1.06 micrometers (6 ns pulse duration), 2nd harmonic 532 nm (120 microsecond(s) duration pulse- 1J max per-pulse) wavelengths, multi-articulated seven mirrors beam guiding device, 20 Hz repetition rate. This lets shots with 600 mJ max energy per pulse and 100 MW peak power per-pulse with a very low beam divergence, 0.5 mrad at full angle; a transverse fast flow 2.5 kW CO2 laser.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this work a treatment for surface preparation to improve mechanical resistance in adhesive bonding of plastic composites reinforced with fibres and metallic material, has been performed using an excimer laser. The following couplings have been selected to reproduce joints commonly used in the aerospace and automotive industry: CFC (carbon fibre composite) with CFC, CFC with Al 2024T3, Al 99% with Al 99%, GFC (glass fibre composite) with zinc-coated sheet in low carbon steel FeP01. The surfaces have been prepared using an excimer laser, adopting several values of laser parameters. The obtained surfaces have been examined by optical and scanning electron microscope: comparative measures of wetting and roughness have been performed to obtain an accurate characterisation and to select the proper finishes suitable to improve the mechanical resistance of the joints. The results obtained show that laser treatment always improves the final resistance of the joint; notable increases, and no significant surface damages have been highlighted. Better results have been obtained with the Al 99% with Al 99% joints which, with a low number of pulses treatment, have shown an increase of mechanical resistance up to the 70%.

This communication reports on the possibility to achieve the direct production of either carbamazepine crystals or carbamazepine–saccharin cocrystals from water/ethanol solvent mixtures by using membrane-based crystallization technology, by choosing the opportune initial conditions.

Encouraging results in copper to steel deep penetration welding with a CO2 laser have been obtained, demostrating yet again that high reflectivity metals can easily be laser processed.The difference in behaviour between the two metals is discussed as are the advantages deriving from working copper without an oxygen assistance gas flow.Mechanical tests and metallurgical considerations confirm the applicability of these results to industry.Encouraging results in copper to steel deep penetration welding with a CO2 laser have been obtained, demostrating yet again that high reflectivity metals can easily be laser processed.The difference in behaviour between the two metals is discussed as are the advantages deriving from working copper without an oxygen assistance gas flow.Mechanical tests and metallurgical considerations confirm the applicability of these results to industry.

The recent achievement of welding copper to: copper, brass and steel with a CO2 laser has given rise to new questions about material processing. The results of a series of experiments carried out in an attempt to understand the physics of the process are reported.