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Diamond-like carbon (DLC) films were deposited using two different types of high current arc evaporation. The first process used a magnetic particle filter to remove droplets from the plasma. For the second process, the samples were put into a metallic cage which was placed directly above the plasma source. For both processes, we varied the substrate temperature from 21 to 350 °C in order to investigate the temperature effect. The samples were characterized using SEM, AFM, XPS, Raman Spectroscopy, Ellipsometry, Photometry, and Nano Indentation in order to compare both methods of deposition and provide a careful characterization of such DLC films. We found that the sp3 content and the hardness can be precisely adjusted by changing the substrate temperature. Furthermore, in the case of unfiltered deposition, the optical constants can be shifted in the direction of higher absorbance in order to produce black and hard carbon coatings.

OBJECTIVE: The objective of this study is to evaluate genetic risks already present before pregnancy in a cohort of pregnant women referred for prenatal genetic counseling exclusively for advanced maternal age (AMA). METHOD: We retrospectively reviewed the records of 1353 women referred over 1 year (2010) for pre-test genetic counseling with the only indication of AMA at three Italian Clinical Genetic Services. RESULTS: Of the 1353 women fulfilling the inclusion criteria of the study, 87 (6.4%) had cumulatively 94 genetic risk factors not previously identified (one risk factor in 80 patients and two risk factors in seven). Twenty-six risk factors (27.7%) concerned heterogeneous or multifactorial conditions and 68 (72.3%) Mendelian or chromosomal disorders and consanguinity.In nine out of these 87 women, the estimated risk for the offspring of a genetic disease or a significant structural anomaly was >5%. Additional testing according to the identified risks was performed in 36 of these 87 women/families. CONCLUSIONS: The proportion of cases with additional risk factors is smaller than reported in previous studies, but it remains substantial and confirms the need for strategies to increase awareness of the public and health professionals responsible for the care of women in childbearing age.

We report on microwave emission from linear parallel arrays of underdamped Josephson junctions, which are described by the Frenkel-Kontorova (FK) model. Electromagnetic radiation is detected from the arrays when biased on current singularities (steps) appearing at voltages Vn=Φ0(nc¯/L), where Φ0=2.07×10-15Wb is the magnetic flux quantum, and c¯, L, and n are, respectively, the speed of light in the transmission line embedding the array, L its physical length, and n an integer. The radiation, detected at fundamental frequency c¯/2L when biased on different singularities, indicates shuttling of bunched 2π kinks (magnetic flux quanta). Resonance of flux-quanta motion with the small-amplitude oscillations induced in the arrays gives rise to fine structures in the radiation spectrum, which are interpreted on the basis of the FK model describing the resonance. The impact of our results on design and performances of new digital circuit families is discussed.

Measurements performed on superconductive networks shaped in the form of planar graphs display anomalously large currents when specific branches are biased. The temperature dependencies of these currents evidence that their origin is due to Cooper pair hopping through the Josephson junctions connecting the superconductive islands of the array. The experimental data are discussed in terms of a theoretical model which predicts, for the system under consideration, an inhomogeneous Cooper pair distribution on the superconductive islands of the network., 10 pages and 4 figures. The paper, as it is, was submitted for publication on March 15, 2013. At the date of submission on the Archive (September 11, 2013) no feedback has yet been received from the referees

Miniaturized gas-sensing devices that use single-walled carbon nanotubes as active material have been fabricated using two different electrode materials, namely, Au/Cr and NbN. The resistive sensors have been assembled aligning by dielectrophoresis the nanotube bundles between 40 μm spaced Au/Cr or NbN multifinger electrodes. The sensing devices have been tested for detection of the H2S gas, in the concentration range 10–100 ppm, using N2 as carrier gas. No resistance changes were detected using sensor fabricated with NbN electrodes, whereas the response of the sensor fabricated with Au/Cr electrodes was characterized by an increase of the resistance upon gas exposure. The main performances of this sensor are a detection limit for H2S of 10 ppm and a recovery time of few minutes. The present study suggests that the mechanism involved in H2S gas detection is not a direct charge transfer between molecules and nanotubes. The hypothesis is that detection occurs through passivation of the Au surfaces by H2S molecules and modification of the contact resistance at the Au/nanotube interface.

We report on experiments conducted on single walled carbon nanotube bundles aligned in chains and connected through a natural contact barrier. The dependence upon the temperature of the transport properties is investigated for samples having different characteristics. Starting from two bundles separated by one barrier deposited over four contact probes, we extend the study of the transport properties to samples formed by chains of several bundles. The systematic analysis of the properties of these aggregates shows the existence of two conduction regimes in the barrier. We show that an electrical circuit taking into account serial and parallel combinations of voltages generated at the junctions between bundles models the samples consistently., 9 pages and 3 figures

Series arrays of Josephson junctions show evidence of a mode in which all the junctions oscillate in synchronism on voltage resonances appearing, in zero external magnetic field, at multiples of the fundamental Fiske step spacing. The measurements show that the current amplitude of the resonances increases linearly as their voltages are summed. Investigation of the nature of the coherent mode by magnetic field responses of arrays and isolated juctions reveals that the oscillations take place in a parameter plane region where dc magnetic fields only activate boundary current and flux-quanta dynamics can take place., 12 pages and 4 figures

In this work we present the study of the sensing properties of Carbon nanotube films. We show the realization of deformation sensors based on composite CNT-polymer films realized by electrochemical deposition starting from a dispersion of SWCNTs and EDOT monomer. The gauge factor (GF) of the sensors has been found to be up to 3–4 times higher than that of the commercial strain gauge. We show also that the CNT have gas sensing properties, that can be applied to different gases, included H2O in gaseous form. Detection can be optimized by means of electrostatic polarization of the film substrate.