Search results for "21"
showing 10 items of 34876 documents
Charge Transport Mechanisms in Heavy-Ion Driven Leakage Current in Silicon Carbide Schottky Power Diodes
2016
Under heavy-ion exposure at sufficiently high reverse bias voltages silicon carbide (SiC) Schottky diodes are observed to exhibit gradual increases in leakage current with increasing ion fluence. Heavy-ion exposure alters the overall reverse current-voltage characteristics of these diodes, leaving the forward characteristics practically unchanged. This paper discusses the charge transport mechanisms in the heavy-ion damaged SiC Schottky diodes. A macro model, describing the reverse current-voltage characteristics in the degraded SiC Schottky diodes is proposed. peerReviewed
Impact of Different Washing Conditions on the Release of Ag Species from Textiles
2016
The paper investigates the Ag release from textiles (socks available in shops, cotton and viscose filled with Ag nanoparticles–AgNPs) into a washing solution under different conditions. The released Ag amount depended on various factors, such as test media (chemical composition, temperature and water volume), metal contents, and textile impregnation conditions. Furthermore, it turned out that the textile type and colour were the main parameters affecting the Ag release. The Ag concentration in the washing solution ranged between 0.015 μg/l and 4.44 μg/l (socks) and between 0.61 μg/l and 103 μg/l (AgNPs–filled cotton). The total Ag percentage released into water during one washing varied con…
Study of the Stability of Citrate Capped AgNPs in Several Environmental Water Matrices by Asymmetrical Flow Field Flow Fractionation
2021
Asymmetrical flow field-flow fractionation (AF4) coupled to UV-Vis and dynamic light scattering (DLS) detectors in series, was tested for stability studies of dispersions of citrate-capped silver nanoparticles (AgNPs) in several water matrices. The main goal is to provide knowledge to understand their possible behavior in the environment for short times since mixturing (up to 180 min). Ultrapure (UPW), bottled (BW1, BW2), tap (TW), transitional (TrW) and sea water (SW) matrices were assayed. Observations were compatible with the aggregation of AgNPs, a change in the plasmon band and a size growth with time were done. Fractograms showed different evolution fingerprints in the function of the…
Localized surface plasmon resonance in silver nanoparticles: Atomistic first-principles time-dependent density-functional theory calculations
2015
We observe using ab initio methods that localized surface plasmon resonances in icosahedral silver nanoparticles enter the asymptotic region already between diameters of 1 and 2 nm, converging close to the classical quasistatic limit around 3.4 eV. We base the observation on time-dependent density-functional theory simulations of the icosahedral silver clusters Ag$_{55}$ (1.06 nm), Ag$_{147}$ (1.60 nm), Ag$_{309}$ (2.14 nm), and Ag$_{561}$ (2.68 nm). The simulation method combines the adiabatic GLLB-SC exchange-correlation functional with real time propagation in an atomic orbital basis set using the projector-augmented wave method. The method has been implemented for the electron structure…
Design and Characterization of Effective Ag, Pt and AgPt Nanoparticles to H2O2 Electrosensing from Scrapped Printed Electrodes
2019
The use of disposable screen-printed electrodes (SPEs) has extraordinarily grown in the last years. In this paper, conductive inks from scrapped SPEs were removed by acid leaching, providing high value feedstocks suitable for the electrochemical deposition of Ag, Pt and Ag core-Pt shell-like bimetallic (AgPt) nanoparticles, onto screen-printed carbon electrodes (ML@SPCEs, M = Ag, Pt or AgPt, L = metal nanoparticles from leaching solutions). ML@SPCEs were characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results were compared to those obtained when metal nanoparticles were synthesised using standard solutions of metal salts (MS@…
Anastasija Verbickaja, o il decadentismo per le masse
2012
1910 is remembered in Russian culture as the year when symbolism declares its crisis, when the post-symbolist movements move their first steps. But a look at the publishing figures is enough to understand that this process passed unnoticed by the majority of the reading public. In early XX-th century, popular literature was already an important and complex phenomenon. The readers of dime novels had no notion of the highbrow movements; the “people's intelligentsia”, on the other hand, opposed them as enemies to their values of social commitment. Anastasia Verbickaia, one of the leaders of the market in the first two decades of the century, although her career had started in the same field, i…
Indagini genetiche e trattamenti prenatali in utero della Sindrome Adreno Genitale (SAG) in una Coorte Siciliana.
2008
La deficienza dell'enzima 21 idrossilasi (21OHD) è la causa più comune di sindrome adrenogenitale (SAG). Il gene implicato è il CYP21 (6p21.3). La SAG è un problema clinico-sociale in quanto nel 95% dei casi genera l'iperandrogenismo dei neonati di sesso femminile. Il trattamento più effettuato in corso di virilizzazzione dei genitali femminili esterni è di tipo chirurgico (genitoplastica). Il trattamento prenatale in utero è una alternativa medica con il fine di compensare il difetto enzimatico e prevenire l'eccesso di androgeni in corso di morfogenesi fetale. Un nuovo protocollo diagnostico-terapeutico prenatale è stato sviluppato sulla base di una terapia precoce (alla 5° WG) con Desamet…
Sindrome di Down da duplicazione della regione critica 21q22.2-q22.3
2007
Zinc Adsorption by Activated Carbon Prepared from Lignocellulosic Waste Biomass
2019
Sawdust was used as a precursor for the production of biomass-based activated carbon. Carbonization and activation are single-stage processes, and steam was used as a physical activation agent at 800 °
The system of protected areas as the core element in a new vision of the Metropolitan City of Palermo
2022
Un processo di urbanizzazione può certamente essere considerato una delle più significative alterazioni antropiche del sistema ambientale in un territorio. Il presente studio vuole comprendere le caratteristiche spaziali della crescita urbana e i suoi impatti sulle componenti ambientali nella Città Metropolitana di Palermo, un'area in cui i livelli di consumo di suolo inedificato e di pregio, e le conseguenti forme di frammentazione ambientale e territoriale, rischiano di compromettere non solo il valore paesaggistico-ambientale dei territori coinvolti ma anche la loro identità. Partendo da queste premesse, questo contributo esplora il rapporto di reciprocità tra ambiente costruito e territ…