149 research outputs found

    Frontal Polymerization and Geopolymerization, the First Example: Organic-Inorganic Hybrid Materials

    Get PDF
    This work shows the first example of frontal geopolymerization, obtained in the same reactor in which the frontal polymerization of 1,6 hexanediolodiaacrylate occurs at the same time; the simultaneous frontal polymerization allows to obtain an organic-inorganic hybrid material in a single step and in a short time (a few minutes), thanks to the exothermicity of the two reactions which are mutually self-supporting. This technique represents the only way to obtain hybrid organic polymer-geopolymer mate-rials: using the classical polymerization (prolonged heating) the reaction is explosive due to the formation of gaseous products, while the polymerization at room temperature, due to the very long times, leads to a phase separation

    The bridge volcanic LIdar-BILLI: A review of data collection and processing techniques in the Italian most hazardous volcanic areas

    Get PDF
    Volcanologists have demonstrated that carbon dioxide (CO2) fluxes are precursors of volcanic eruptions. Controlling volcanic gases and, in particular, the CO2 flux, is technically challenging, but we can retrieve useful information from magmatic/geological process studies for the mitigation of volcanic hazards including air traffic security. Existing techniques used to probe volcanic gas fluxes have severe limitations such as the requirement of near-vent in situ measurements, which is unsafe for operators and deleterious for equipment. In order to overcome these limitations, a novel range-resolved DIAL-Lidar (Differential Absorption Light Detection and Ranging) has been developed as part of the ERC (European Research Council) Project "BRIDGE", for sensitive, remote, and safe real-time CO2 observations. Here, we report on data collection, processing techniques, and the most significant findings of the experimental campaigns carried out at the most hazardous volcanic areas in Italy: Pozzuoli Solfatara (Phlegraen Fields), Stromboli, and Mt. Etna. The BrIdge voLcanic LIdar-BILLI has successfully obtained accurate measurements of in-plume CO2 concentration and flux. In addition, wind velocity has also been retrieved. It has been shown that the measurements of CO2 concentration performed by BILLI are comparable to those carried out by volcanologists with other standard techniques, heralding a new era in the observation of long-term volcanic gases

    Impact of lesion delineation and intensity quantisation on the stability of texture features from lung nodules on ct: A reproducible study

    Get PDF
    Computer-assisted analysis of three-dimensional imaging data (radiomics) has received a lot of research attention as a possible means to improve the management of patients with lung cancer. Building robust predictive models for clinical decision making requires the imaging features to be stable enough to changes in the acquisition and extraction settings. Experimenting on 517 lung lesions from a cohort of 207 patients, we assessed the stability of 88 texture features from the following classes: first-order (13 features), Grey-level Co-Occurrence Matrix (24), Grey-level Difference Matrix (14), Grey-level Run-length Matrix (16), Grey-level Size Zone Matrix (16) and Neighbouring Grey-tone Difference Matrix (five). The analysis was based on a public dataset of lung nodules and open-access routines for feature extraction, which makes the study fully reproducible. Our results identified 30 features that had good or excellent stability relative to lesion delineation, 28 to intensity quantisation and 18 to both. We conclude that selecting the right set of imaging features is critical for building clinical predictive models, particularly when changes in lesion delineation and/or intensity quantisation are involved

    Equilibrium properties of a Josephson junction ladder with screening effects

    Full text link
    In this paper we calculate the ground state phase diagram of a Josephson Junction ladder when screening field effects are taken into account. We study the ground state configuration as a function of the external field, the penetration depth and the anisotropy of the ladder, using different approximations to the calculation of the induced fields. A series of tongues, characterized by the vortex density ω\omega, is obtained. The vortex density of the ground state, as a function of the external field, is a Devil's staircase, with a plateau for every rational value of ω\omega. The width of each of these steps depends strongly on the approximation made when calculating the inductance effect: if the self-inductance matrix is considered, the ω=0\omega=0 phase tends to occupy all the diagram as the penetration depth decreases. If, instead, the whole inductance matrix is considered, the width of any step tends to a non-zero value in the limit of very low penetration depth. We have also analyzed the stability of some simple metastable phases: screening fields are shown to enlarge their stability range.Comment: 16 pp, RevTex. Figures available upon request at [email protected] To be published in Physical Review B (01-Dec-96

    Further progress/developments, on surface/bulk treated Constantan wires, for anomalous heat generation by H2/D2 interaction

    Get PDF
    In the framework of those studies aimed to analyze anomalous effects (thermal and/or nuclear) due to the interaction among some specific materials (pure and/or alloys) and H2 (or D2), we focused, since 2011, on a specific alloy called Constantan (Cu55-Ni44-Mn1). We selected such material using our own considerations and intuitions and because, according to a scientific paper [1], it has the largest energy value for dissociation of H2 to 2H, i.e. about 3eV. Among others B. Ahern suggested that Ni-Cu-H can be used for heat generation. We improved the preparation procedure of such wire from simple thermal treatments (up to May 2012 [2])to more sophisticated ones, with more tight control of the multilayered (400-700) surface structures. Some of the results were presented at ICCF17, Aug. 2012 [3]. After [3], several groups asked to make their own experiments using such kind of wires ([phi]=200[mu]m, l=100cm) to cross-check (and possibly improve) our results. Some of such Researchers (group of M. Fleischmann Memorial Project; U. Mastromatteo) made public their (positive) results since Dec. 14, 2012 at Ministry of Aeronautics in Rome, Italy. In short, using an (home-made) apparatus integrated with an acquisition system (type PXi) by National Instruments, we made, since September 2012, not mentioning qualitative reconfirmation of previous results, further and unexpected progress and discoveries: a) We developed a new kind of procedure of measurement (about anomalous excess heat) under dynamic vacuum, to avoid the effect of different thermal conductivity, inside the gas cell, due to type of gas and pressure variation: the wire didn't lose, macroscopically, H even at T=600[degrees]C. b) We developed a new, very simple, type of surface coating (2 layers) that is nano-diamandoidslike; c) We observed, at least 2 times, the phenomenon of water splitting due to catalytic effect of surface treated Constantan. Such phenomenon is larger in comparison with what expected just by thermal splitting (wires temperature of about 300-500[degrees]C); d) We observed a very large variation (about a factor 100) of Resistive Thermal Coefficient (RTC) of the wire used (400 layers) as the amount of H (related to the macroscopic value of resistive ratio R/Ro, normalize to empty wire Ro) increased. As example, with "treated" virgin wire (w/o H2) the RTC was about 5*10-6 and increased to6*10-4 when the R/Ro reduced to 0.68; temperature range 20-300[degrees]C. The RTC is larger with D in respect to H. Experiments are in progress also at 77K. e) Overall results are affected by previous operating conditions

    Improved understanding of self-sustained, sub-micrometric multi-composition surface Constantan wires interacting with H2 at high temperatures: experimental evidence of Anomalous Heat Effects

    Get PDF
    This article is an extension of what presented by our team at 17th International Conference on Cold Fusion, ICCF-17, in Daejon, Korea, in 2012 [1]. It documents the improvements on Constantan-related experiments, started in 2011, in order to study the feasibility of new Nickel based alloys that are able to absorb proper amounts of Hydrogen (H2) and/or Deuterium (D2) and that have, in principle, some possibility to generate anomalous thermal effects at temperatures >100°C. The interest in Ni comes in part because there is the possibility to use also H2 instead of expensive D2. Moreover, cross-comparison of results using H2 instead of D2 can be made and could help the understanding of the phenomena involved (atomic, nuclear, super-chemical origin?) due to the use of such isotopes. Keywords: calorimeter, LENR, Nickel based alloys, sub-micrometric surface

    Impact of alien insect pests on Sardinian landscape and culture

    Get PDF
    Geologically Sardinia is a raft which, for just under thirty million years, has been crossing the western Mediterranean, swaying like a pendulum from the Iberian to the Italian Peninsula. An island so large and distant from the other lands, except for its "sister" Corsica, has inevitably developed an autochthonous flora and fauna over such a long period of time. Organisms from other Mediterranean regions have added to this original contingent. These new arrivals were not randomly distributed over time but grouped into at least three great waves. The oldest two correspond with the Messinian salinity crisis about 7 million years ago and with the ice age, when, in both periods, Sardinia was linked to or near other lands due to a fall in sea level. The third, still in progress, is linked to human activity. Man has travelled since ancient times and for many centuries introduced allochthonous species to Sardinia which radically modified the native flora and fauna, but always at a very slow and almost unnoticeable rate. The use of sailing or rowing boats, with their low speeds, hindered the transport of living organisms from one place to another. The use of the steam boat, introduced around 1840 but widely diffuse around 1870-1880, opened the doors to more frequent arrivals and also to organisms from the American Continent. This technical innovation had an influence over the whole world economy, with its well-known grain crisis, and coincided in Sardinia with the arrival of Roman dairymen, producers of pecorino cheese and the beginning of the expansion of sheep farming which would continue uninterrupted until the present day. In this period of sudden social and environmental change, an insect was introduced which would turn out to be probably the most economically devastating agricultural pest in Europe: the Grape Phylloxera. The vineyard and wine business collapsed first in France then in Italy. The Phylloxera arrived in Sardinia in 1883 and wine production crashed a very short time later and only resumed after the distribution of American vine rootstock at the beginning of the 20th Century. From then, vine cultivation in Europe was modified with the essential use of this rootstock. Since then methods of transport have increased enormously in number and speed. The number of allochthonous and invasive species has increased proportionally: some of them along with exotic plants which are cultivated on the island, others following man in his activities. Often these new pests attack and destroy ornamental plants which have become part of the Sardinian landscape, causing it to change; just as often their presence requires methods of pest management which are different from the traditional methods on specific crops; finally in at least one case (the Asian tiger mosquito) they pose a threat to our health
    • …
    corecore