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This study attempted to produce polymeric microfibers with low-cost and photocatalytic properties, making it possible to remedy two modern problems, plastic disposal and irregular effluent disposal, for which we used the solution blows pinning (SBS) technique to produce recycled polystyrene (PS) microfibers (recycled waste from transparent barrel pen), the use of the SBS also has good mobility for the benefit of fibers, allowing the fibers to be produced directly under the surface where intend to be used, through the SEM was found the ideal concentration to produce uniform microfibers. With the minor average diameter, FTIR analysis of the fibers showed peak characteristics of PS, demonstrating that most of the transparent barrel pen is composed of PS. The as-prepared fibers of recycled PS were incorporated into their polymer solution with a TiO2 Degussa P25 concentration of 10% (w/w) concerning the polymer mass. For the study of photocatalytic activity, the dye Rhodamine B was used as an indicator. Excellent photocatalytic activity, XRD pattern of PS and PS/TiO2-10% fibers showed PS and TiO2 in two phases, anatase and rutile.

Lead-210 is a naturally occurring radionuclide of great importance for environmental studies. Its vertical distribution in soil combined with that of Radium–226 may provide useful information on radon exhalation from the ground, or radon carried by ground water. Previous research has shown that natural radioactivity levels–in particular Lead–210 and Radium–226 activity in the ground–may be higher near hot springs. In this work two different locations near hot springs were selected for soil sampling: Kamena Vourla and Thermopylae, both in Greece. Depending on the special soil characteristics of each sampling location, it was decided to collect soil cores up to a depth of 20 cm from Kamena Vourla, and surface soil from Thermopylae.The soil cores were then sectioned into 1 cm slices, while the surface soil samples were separated into seven particle size fractions by dry sieving. All samples were analysed by high resolution gamma-ray spectrometry at the Nuclear Engineering Department of the National Technical University of Athens, using an XtRa germanium detector and a Low Energy germanium detector, to determine: (a) the terrestrial natural radionuclides Thorium–234, Radium–226, Lead-210, Radium–228, Thorium–228 and Potassium–40, (b) the cosmogenic radionuclide Beryllium–7, and (c) the artificial radionuclides Cesium–137 and Ruthenium–106. It is worth mentioning that, the Ruthenium–106 that was detected in samples collected from both sampling locations is the result of an accidental release over Europe, apparently originated in Russia, a few days before the sampling took place. The vertical profile of the radionuclides obtained from the core sample analysis indicated a disturbance in the first 7 cm of soil, while at greater depth the concentrations for all radionuclides were as expected. Lead-210 activity was higher than that of Radium–226, showing a disruption in the radioactive equilibrium, as expected. The analysis of the size-fractionated samples showed a higher activity concentration of Lead–210 and Cesium–137 in the finer fractions. The radioactive equilibrium between Thorium–234, Radium–226, and Lead–210 was found to be significantly disturbed in all size fractions.

The production of Molded Interconnect Devices (MIDs) may be achieved through different processes. In this work Centro Ricerche Plast-optica (CRP) has chosen to evaluate, implement and assess Laser Direct Structuring (LDS) and In Mold Labeling (IML) technologies for the production of MIDs. Both alternative methods have been analyzed starting with a 2D component, mainly used for implementation and optimization of the process, and finally a more complex 3D component, that has been designed and produced. The first phase of the activity regards the production of several conductor patterns on planar substrates dedicated to evaluate properties as conductors resistance, adhesion, SMD components solderability, wire bondability of bare LED dice etc. In the case of IML, a flexible circuit has been over-molded during the production of the component by injection molding process: planar parts have been tested also in terms of adhesion of flexible circuit to the injected polymer. The second phase of the activity concerns the production of 3D circuits. Both technologies have been implemented in order to select to materials, process conditions and parameters, design rules and to verify the reliability in the automotive severe conditions. Exploitation of technologies have been performed on an automotive rear lamp. A prototype has been produced in LDS technology and allowed to define the conditions that make economically affordable this solution. Differently, the IML technology allowed to produce a completely new device by embedding a planar electronic circuits into the plastic material.

In this work we have built a face recognition system using a new method based on recent advances in compressed sensing theory. The authors propose a method for recognizing faces that is robust to certain types and levels of occlusion. They also present tests that allow to assess the incidence of the proposed method.

Today, the III–V compound semiconductor solar cells represent the most promising photovoltaic technology to achieve the grid parity, thanks to their proven capability to work at high concentration factors (H-CPV: high concentration photovoltaics) with demonstrated conversion efficiencies higher than 40% in the spectral conditions typical of the Earth surface (AM1.5D). One of the issues to be investigated in the H-CPV systems is the reliability of the solar cell receivers. In fact in concentration conditions the thermal and mechanical stress on the solar cell, mounted on receivers, is very significant with respect to flat panel technology. This paper proposes a method, typically used in the LED industry, to test, in accelerated conditions, the H-CPV solar receivers. The receivers, based on III–V solar cells, size 2.1 × 2.1 mm2 from CESI, were built by chip on board technology at CRP labs, and characterized for 800 h to simulate 20 years of in-field operation in concentration regime (500×).

The recent IceCube discovery of 0.1-1 PeV neutrinos of astrophysical origin opens up a new era for high-energy astrophysics. Although there are various astrophysical candidate sources, a firm association of the detected neutrinos with one (or more) of them is still lacking. A recent analysis of plausible astrophysical counterparts within the error circles of IceCube events showed that likely counterparts for nine of the IceCube neutrinos include mostly BL Lacs, among which Mrk 421. Motivated by this result and a previous independent analysis on the neutrino emission from Mrk 421, we test the BL Lac-neutrino connection in the context of a specific theoretical model for BL Lac emission. We model the spectral energy distribution (SED) of the BL Lacs selected as counterparts of the IceCube neutrinos using a one-zone leptohadronic model and mostly nearly simultaneous data. The neutrino flux for each BL Lac is self-consistently calculated, using photon and proton distributions specifically derived for every individual source. We find that the SEDs of the sample, although different in shape and flux, are all well fitted by the model using reasonable parameter values. Moreover, the model-predicted neutrino flux and energy for these sources are of the same order of magnitude as those of the IceCube neutrinos. In two cases, namely Mrk 421 and 1H 1914-194, we find a suggestively good agreement between the model prediction and the detected neutrino flux. Our predictions for all the BL Lacs of the sample are in the range to be confirmed or disputed by IceCube in the next few years of data sampling. © 2015 The Authors.

Cu-alkali ion exchange in silicate glasses gives rise to a peculiar copper distribution, with the presence of both the Cu2+ and Cu+ oxidation states. Grazing incidence X-ray absorption near-edge structure spectroscopy and secondary ion mass spectrometry were performed on different ion-exchanged samples. The results show that the Cu2+/Cu+ ratio is strongly depth-dependent. The relative presence of the two species throughout the exchanged region turns out to be governed by their different diffusion regimes, while the chemistry of the red-ox process is shown to play a minor role. A phenomenological model is proposed to describe the diffusion process.

Lithium niobate crystals doped with erbium by the ion exchange process were studied by means of extended X-ray absorption fine structure spectroscopy and secondary ion mass spectrometry. The study of the local atomic order allowed the determination of the erbium environment in the crystal matrix and the investigation on the role of preparation conditions.

Ferromagnetic films of HCP cobalt with a thickness above 50 nm possess an out-of-plane magnetization. Magnetic force microscopy (MFM) is used to investigate the modulated domains of alternatively up and down magnetization. By applying a perpendicular magnetic field, the low-energy stripe configuration undergoes a zigzag distortion. As is revealed by MFM, a further increase of the maximum applied field produces a pinching of the stripes, which break up into magnetic bubbles. We show to which extent the formation of two types of topologically different bubbles can explain the particular shape of hysteresis curves of these cobalt films.

Nanocrystals of wide band gap materials (GaN and In2O3) were synthesized by sequential ion implantation in dielectric substrates, followed by thermal annealing of the samples. Transmission electron microscopy, extended X-ray absorption fine structure spectroscopy and grazing incidence X-ray diffraction analyses confirmed the formation of GaN and In2O3 crystalline nanoparticles. Blue shift of the near-edge photoluminescence (PL) band (quantum confinement effect) was observed for GaN nanocrystals. A strong PL band peaked at 3.35 eV was detected upon excitation of In2O3 nanocrystals at 5.20 eV.

The success of a new CPV prototype depends on modules quality and assembly compliance with existing Standards, such as IEC 62108, 62670, 62787, and others still under development/approval for performance evaluation. The overall CPV system reliability is based on the quality of the subcomponents such as the optics, the cells, the electronics and the assembly of the whole system, but there is a dramatic lack of technical specifications for new prototypes to comply with. The Italian project SCOOP (SOLAR CONCENTRATION TECHNOLOGIES FOR PHOTOVOLTAIC SYSTEMS) was aimed at developing an Italian network of laboratories and industrial facilities to enter the CPV market. The project, funded by the Ministry of Industry, started in 2009 and ended at the end of 2013. SCOOP addressed the development of solar cells, optical systems and inverters, to be used in four different CPV prototypes. The development of a network of laboratories specialized to test, verify and check components such as plastic materials, optics, cells, electronics and module/assembly at prototype and industrial scale has been one of the main targets of the project. Within the project a set of protocols for the testing of subcomponents, components, modules and the final systems have been defined and validated. © 2014 IEEE.

The morphology and distribution of Co clusters on Au(111) can be controlled: from very small (a few atoms) randomly distributed clusters to bigger (several 100 atoms) self-organized clusters on a regular network. The substrate temperature imposed during growth turns out to be the leading parameter, deciding for spontaneous organization of adsorbed metal atoms. From a detailed variable temperature scanning tunneling microscopy (STM) study, it is suggested that this way of organizing matter at the nanoscale may be used to achieve new material properties. In particular, from in situ magnetic measurements on the example of Co on Au(111), it is shown that the direction of the magnetization can be adjusted from in-plane to out-of-plane, depending on the growth condition.

Atomically thick cobalt layers are grown on Au(111) by ultrahigh vacuum low-temperature deposition. Low-temperature deposition precludes the formation of three-dimensional cobalt bilayers clusters that grow in arrays at room temperature. As a result, ferromagnetic Co films with an anomalous in-plane magnetic anisotropy are obtained for thicknesses above 1.6 ML. Annealing produces an irreversible reorientation of the anisotropy from in plane to out of plane. However, a preferential in-plane anisotropy can be stabilized by covering the Co with a gold film.

The early growth stages of Co structures on Au(111) have been analyzed by scanning tunneling microscopy and their magnetic properties simultaneously measured, in situ, by Kerr effect and, ex situ by superconducting quantum interference device. With increasing cobalt coverage, cobalt clusters, organized on the lattice of the $22\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ zigzag reconstruction coalesce into one-dimensional (1D) chains at a coverage of 1.0 monolayer (ML) and then into a nearly continuous film at 2 ML. While this well-defined growth mode is dictated by the presence of ordered point dislocations at the zigzag reconstruction of the relaxed gold surface, anomalous nucleation and growth is also observed when large domains of strained linear reconstructions are present. Two families of clusters must then be considered with important consequences for magnetic properties. When only the zigzag reconstruction is present, the onset of long-range, 2D ferromagnetism is observed at a coverage of 1.6 ML of cobalt. A Monte Carlo simulation of an anisotropic Heisenberg model describes well transitions from 0D cluster superparamagnetism, to 1D Ising behavior and finally to 2D ferromagnetism as a function of cobalt coverage, in good agreement with experimental results.

The mechanism of cobalt-cluster incorporation into a Au(111) substrate is followed by variable temperature STM, Auger spectroscopy, and in situ magneto-optic Kerr (MOKE) measurements. Upon thermal activation, cobalt clusters sink into the substrate by simultaneously expelling gold atoms which, in turn, contribute by embedding the remaining cobalt clusters. Although important mass transport occurs during this operation, MOKE indicates that the clusters remain globally undisturbed, until finally, irreversible cluster fragmentation and dissolution occur above 600 K.

A new method to fabricate transparent head-up display on glass has been developed. The method exploits the integration of the Aerosol Jet® Process in the Chip On Board technology.

The aim of this study was to determine the cestodes species of the order Trypanorhyncha that parasite the blackfin goosefish, Lophius gastrophysus Miranda-Ribeiro, 1915 purchased from fishermen, markets and exportation fish industries from municipalities of Cabo Frio, Niterói, Duque de Caxias and Rio de Janeiro, emphasizing their parasite indexes, sites of infection and higienic-sanitary importance. Eighty seven specimens of L. gastrophysus were necropsied from March 2000 to December 2005. Forty one fish (47%) were parasitized by metacestodes of Trypanorhyncha. The collected species were Tentacularia coryphaenae, Nybelinia sp., Mixonybelinia sp. and Progrillotia dollfusi. Most of the parasitized fish (92.7%), presented metacestodes of Trypanorhyncha, in the abdominal muscles and in muscles of commercial importance (lateral back-dorsum), belonging to the species T. coryphaenae, Nybelinia sp., Mixonybelinia sp. Only three (7.3%) fish specimens did not present trypanorhynch metacestodes in the muscles, two of them were parasitized by Nybelinia sp. on the mesentery and the celomatic cavity and the other by P. dollfusi on the celomatic cavity. On some individuals, Mixonybelinia sp. caused equimotic hemorragic lesions on the fascia of the abdominal muscles. The presence of Trypanorhyncha metacestodes in the muscles does not represent a risk of infection for humans, but they have a negative effect on fish aesthetics because of the repugnant aspect, causing consumer rejection and the prohibition for commercial purpose by sanitary inspectors. Parasites of the order Trypanorhyncha are recorded in L. gastrophysus for the first time.

It has recently been shown that lustre decoration of medieval and Renaissance pottery consists of silver and cop- per nanoparticles dispersed in the glassy matrix of the ceramic glaze. Here the findings of an X-ray absorption fine structure (XAFS) study on lustred glazes of shards belonging to 10th and 13rd century pottery from the National Museum of Iran are reported. Absorption spectra in the visible range have been also measured in order to investigate the relations between colour and glaze composition. Gold colour is mainly due to Ag nanoparticles, though Ag + ,Cu + and Cu 2 + ions can be also dis- persed within the glassy matrix, with different ratios. Red colour is mainly due to Cu nanoparticles, although some Ag nanopar- ticles, Ag + and Cu + ions can be present. The achievement of metallic Cu and the absence of Cu 2 + indicate a higher reduc- tion of copper in red lustre. These findings are in substantial agreement with previous results on Italian Renaissance pottery. In spite of the large heterogeneity of cases, the presence of cop- per and silver ions in the glaze confirms that lustre formation is mediated by a copper- and silver-alkali ion exchange, followed by nucleation and growth of metal nanoparticles.

In this work the site of Er ions in a silica matrix containing Si nanoclusters (nc) is investigated. The Er ions are introduced into a silica matrix containing Si nanoclusters by ion implantation. The X-ray absorption spectroscopy (EXAFS), performed at Er LIII-edge shows that the Er site in the matrix strongly depends on the preparation conditions; the effect of the implantation dose on the local structure around Er is addressed. The data demonstrate that the Er atoms are surrounded in the first shell by O atoms. Moreover, an increasing in the Er implantation dose implies an increase of the number of O atoms in the first shell and of their distance to the Er central atom, leading to the formation of a Er site more similar to that of bulk Er2O3.

The magnetic properties of Co–Cu/silica nanocomposites prepared by sequential ion implantation have been investigated. The nanostructure is formed of 4 nm average size particles dispersed in silica matrix and with mainly FCC structure. The hysteresis loops at 3 K indicate that the nanoparticles have uniaxial anisotropy with values smaller than that of single Cobalt implants. The samples are characterized by a superparamagnetic behavior with blocking temperatures that depend on the Co/Cu implanted ratio, and the blocking temperature distributions are narrower than those obtained by taking into account only the particle size distribution. Results are discussed considering size effects and that the nanoparticles are formed of a Co–Cu solid solution or only of Co.

Cu-alkali ion exchange is a suitable way to dope superficial layers of silicate glasses well beyond the Cu solubility limits, with the possibility of controlling nanocluster nucleation and growth by subsequent proper treatments. The ion exchange process gives rise to a peculiar copper distribution, with the possible presence of different oxidation states, namely, Cu+ and Cu2+. The modelization of the copper diffusion process is necessary for defining an effective preparation protocol for the copper-doped composites. In this framework, suitable techniques capable to investigate the local atomic environment of Cu atoms are crucial. With this aim, X-ray absorption fine structure (XAFS) spectroscopy in grazing incidence mode was performed using a synchrotron source on different ion-exchanged samples. Based on the experimental results, a phenomenological model is used to describe the diffusion process.

Lustre is one of the most important decorative techniques of the Medieval and Renaissance pottery of the Mediterranean basin, capable of producing brilliant metallic reflections and iridescence. Following the recent finding that the colour of lustre decorations is mainly determined by copper and silver nanoclusters dispersed in the glaze layer, the local environment of copper and silver atoms has been studied by extended X-ray absorption fine structure (EXAFS) spectroscopy on original samples of gold and red lustre. It has been found that, in gold lustre, whose colour is attributed mainly to the silver nanocluster dispersion, silver is only partially present in the metallic form and copper is almost completely oxidised. In the red lustre, whose colour is attributed mainly to the copper nanocluster dispersion, only a fraction of copper is present in the metallic form. EXAFS measurements on red lustre, carried out in the total electron yield mode to probe only the first 150 nm of the glaze layer, indicated that in some cases lustre nanoclusters may be confined in a very thin layer close to the surface.

Extended X-ray absorption fine structure analysis is used to determine the silver local environment in silicate glasses doped by the Ag-alkali ion-exchange process, followed by different treatments, namely, ion irradiation, thermal annealing in reducing atmosphere, laser irradiation. The obtained results indicate that metal nanocluster composites with different cluster structures may be formed with these multistep methodologies, pointing out the role of the preparation parameters in giving rise to different features. Lattice parameters and cluster diameter were determined by grazing incidence X-ray diffraction.

The short-range order and the crystalline structure of AuCu and AuAg alloy nanoclusters obtained by sequential ion implantation in silica are investigated by extended X-ray absorption fine structure (EXAFS) spectroscopy and by grazing incidence X-ray diffraction (GIXRD). While in the case of AuAg alloy the nearest neighbor interatomic distances correspond to the lattice parameter, in the case of chemically disordered solid solution AuCu alloy a significant deviation from the virtual crystal approximation is observed: the Au–Au, Cu–Cu and Au–Cu nearest neighbor distances are different, only their average corresponding to the fcc lattice parameter. This result, mainly related to the different atomic radius of the two alloy components, is for the first time reported for nanostructured systems.

Lithium niobate crystals doped with erbium by the ion exchange process were studied by means of extended X-ray absorption fine structure spectroscopy and secondary ion mass spectrometry. The study of the local atomic order allowed the determination of the erbium environment in the crystal matrix and the investigation on the role of preparation conditions.

Fast nonlinear refractive index and nonlinear absorption coefficient were measured at 527 nm of wavelength for composites formed by either copper or gold-silver alloy nanoparticles embedded in silica by the Z-scan technique. A single 6 ps long pulse from a Nd:glass laser was used in the Z-scan measurement, allowing to determine the fast (i.e., non-thermal) component of the nonlinear response. Both the composites exhibit relatively large (and negative for the Au–Ag alloy) nonlinear index. Transmission electron microscopy, optical absorption and extended X-ray absorption fine structure spectroscopies were also used to characterize the samples. Some figures of merit for the two samples were evaluated, as well as the third-order optical susceptibilities.

Following the recent finding that luster decorations in glazes of historical pottery consist of copper and silver nanoparticles dispersed in a glassy medium, the glaze in-depth composition and distribution of copper nanoparticles, copper ions, and their local environment have been studied in original samples of gold and red luster. The study has been fully carried out by nondestructive techniques such as Rutherford backscattering spectrometry, ultraviolet and visible spectroscopy, x-ray fluorescence, and extended x-ray absorption fine structure (EXAFS). Elemental analyses indicate that gold decorations are characterized by silver and copper, while red decorations by copper only. The color is determined mainly by metal nanoparticles. Specifically, silver nanoparticles determine the gold color, while the red color is determined by nanoparticles of copper. EXAFS measurements, carried out at the Cu K edge, indicate that in both gold and red luster copper is mostly the oxidized form (Cu+ and Cu2+) with a large prevalence of Cu+. States and local environment of copper ions are similar to those found in copper-alkali ion-exchanged silicate glass samples. This strongly supports the view that luster formation is mediated by a copper- and silver-alkali ion exchange as a first step, followed by nucleation and growth of metal nanoparticles.

Copper–cobalt nanostructures are expected to exhibit peculiar magnetic and optical properties that make them interesting for several application fields. In particular, nanoclusters of these metals can be formed upon ion implantation in dielectric matrices. In this work, Co + and Cu + ions were sequentially implanted into fused silica. Samples were analyzed by different synchrotron radiation-based techniques, namely, extended X-ray absorption fine structure spectroscopy and grazing incidence X-ray diffraction. The obtained cluster structure, and so its magnetic features, are observed to depend on the sequential implantation order.

CO adsorption on a PtCo(111) surface was studied by scanning tunneling microscopy. Comparison of images with chemical contrast of Pt and Co and images showing the CO molecules indicates that CO resides exclusively on top of Pt sites and never on Co. CO bonding is highly sensitive to the chemical environment. The probability to find CO on a Pt atom increases drastically with the number of its Co nearest neighbors. Ab initio calculations show that this ligand effect is due to different positions of the center of the Pt d band.

We have analyzed the magnetic domain structure in high quality molecular beam epitaxy (MBE) grown (0001)-hcp cobalt films of thicknesses varying from 10 to 500 nm for which the magnetic domain width is of the order of the film thickness. As the thickness of the film is increased, the magnetization turns from fully in plane (10 nm) to fully out of plane (50 nm) over a relatively large thickness range. Above 50 nm, the local domain imaging by magnetic force microscopy (MFM) together with overall magnetization measurements confirm the characteristic multidomain structure with perpendicular orientation predicted by Kittel. The periodicity of domains is then described by a \ensuremath{\surd}d law (where d is the film thickness) that leads to the determination of domain wall energies. The occurrence of magnetic bubbles and periodic stripe patterns is visualized by variable field MFM. \textcopyright{} 1996 The American Physical Society.

Applied Surface Science 172 (2001) 190Fig. 4. Comparison between films grown at: (a) 30 K, 1.7 ML (100 100 nm) and (b) 300 K, 1.0 ML (150 150 nm). In the first case, acompact stacking of monolayer thick clusters with a diameter of 0.7 nm occurs, while the growth at 300 K leads to bilayer clusters with alateral dimension of 7 nm.

We present a study of magnetic dot arrays fabricated in Ru(5 nm)/Co/Ru(32 nm) films with cobalt thickness varying from 10 to 500 nm. Large array areas up to 5×5 mm2 have been obtained with lateral dot size and spacing of 0.5 μm. The magnetization curves are characteristic of a perpendicular magnetized multidomain structure. Lateral size reduction does not drasti‐ cally change the domain structure but has immediate consequences on the nucleation and saturation fields. A magnetic force microscopy study confirms the perpendicular multidomain struc‐ ture and provides intrinsic magnetic characteristics.

Composite silica films containing metal nanoclusters were prepared by the rf- sputtering technique, in which SiO2 was co-deposited with gold+copper, gold+silver, or copper+silver. The formation of either pure or alloy clusters was studied by extended X-ray absorption fine structure spectroscopy and transmission electron microscopy. For all systems, the presence of alloy aggregates was evidenced. Moreover, small amounts of pure metal aggregates as well as dispersed or oxidized dopants were observed. 61.46.+w Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals – 61.10.Ht X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc. – 81.05.Pj Glass-based composites, vitroceramics