fabrication of ni ti al schottky contact to n type 4h sic under various annealing conditions

Forward I-V characteristics of a silicon carbide Schottky diode, with triple layer metallization Ni/Ti/Al as Schottky contact, are presented. Effects of different annealing conditions on the Schottky barrier height and ideality factor are discussed. The diodes were annealed in inert Ar atmosphere for 30 minutes at temperatures ranging from 600 °C to 800 °C. The ideality factors of the four diodes, chosen out of 20 diodes, range from 1.02 to 1.13 and the Schottky barrier heights range from 1.47 eV to 3.17 eV

La paratubercolosi negli ovini e caprini I: prolegomeni allo studio delle cause predisponenti a questa malattia

La paratubercolosi, o enterite paratubercolare (conosciuta anche come malattia di Johne), è una patologia infettiva ad andamento cronico sostenuta da Mycobacterium avium subsp. paratuberculosis (MAP). È diffusa ovunque si pratichi l’allevamento ovino e caprino, rappresentando una delle malattie infettive più importanti per i danni arrecati agli allevamenti. Alla diffusione del MAP hanno contribuito specifici fattori gestionali, ma soprattutto la commercializzazione incontrollata di animali, con conseguente aumento dell’incidenza della malattia e prevalenza di allevamenti infetti ormai variabile tra il 7 ed il 60% su scala mondiale. In questo quadro si colloca il progetto PON “EpiSud-Programma per lo sviluppo di metodologie per l’identificazione ed il controllo di infezioni micobatteriche animali”, che vede il Parco Tecnologico Padano come proponente e l’Istituto Zooprofilattico della Sicilia nonché l’Università degli Studi di Bari Aldo Moro (DETO-Sez. Cliniche veterinarie e Produzioni Animali) in qualità di partner. L’Università di Bari, in particolare, sta conducendo un’indagine epidemiologica in Puglia su allevamenti estensivi ovini e caprini al fine di studiare la prevalenza della malattia ed i fattori di rischio scatenanti l’infezione in relazione alle pratiche gestionali adottate dagli allevatori. L’indagine è ancora in fieri ed è prematuro trarre conclusioni circa i dati epidemiologici; è tuttavia possibile, ancorché su dati parziali, avanzare ipotesi circa i fattori di rischio. Data la natura complessa di detti fattori, per l’analisi è stato scelto un approccio multivariato, cosicché nel presente lavoro si riportano i risultati dei primi dati raccolti mediante la somministrazione agli allevatori di un’apposita scheda aziendale, redatta al fine di reperire una serie di informazioni di carattere strutturale, igienico-sanitario e gestionale

Silicon resonant microcantilevers for absolute pressure measurement

This work is focused on the developing of silicon resonant microcantilevers for the measurement of the absolute pressure. The microcantilevers have been fabricated with a two-mask bulk micromachining process. The variation in resonance response of microcantilevers was investigated as a function of pressure 10−1-105 Pa, both in terms of resonance frequency and quality factor. A theoretical description of the resonating microstructure is given according to different molecular and viscous regimes. Also a brief discussion on the different quality factors contributions is presented. Theoretical and experimental data show a very satisfying agreement. The microstructure behavior demonstrates a certain sensitivity over a six decade range and the potential evolution of an absolute pressure sensor working in the same rang

New results from the NUMEN project

NUMEN aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. First evidence about the possibility to get quantitative information about NME from experiments is found for the (18O,18Ne) and (20Ne,20O) reactions. Moreover, to infer the neutrino average masses from the possible measurement of the half-life of 0νββ decay, the knowledge of the NME is a crucial aspect. The key tools for this project are the high resolution Superconducting Cyclotron beams and the MAGNEX magnetic spectrometer at INFN Laboratori Nazionali del Sud in Catania (Italy). The measured cross sections are extremely low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest. peerReviewe

Effect of artemisinin derivatives on endothelial cells: role of hypoxia

Artemisinin derivatives are the most effective and safe antimalarial drugs available. They possess anti-angiogenic and antitumor activity as well. We reported that the inhibition of growth and differentiation of endothelial cells (EC) depends on the artemisinin derivative used (D\u2019Alessandro 2007). We extended here these observations by evaluating the role of hypoxia in the response of EC to artemisinins. Hypoxia plays a crucial role both in malaria and tumours and is a potent signal for EC itself. In severe malaria, microvascular occlusion by infected red blood cells generates a hypoxic microenvironment. In cancer, the growth of tumour mass causes a failure in the oxygen and nutrients supply and generates hypoxia. We found that dihydroartemisinin (DHA), the active metabolite of most artemisinins, causes a time and dose-dependent inhibition of EC growth which is influenced by the oxygen tension: at low doses (those found in plasma of malaria patients) DHA is more active in hypoxia, whereas at high doses (those proposed as antiangiogenic and antitumor) it is more effective in normoxia. At high doses DHA induces EC apoptosis and affects the cell cycle via oxidative stress. At low doses cytostasis seems to be present since neither apoptosis nor oxidative stress were detected. The implication of these findings for therapeutic regimens with artemisinins is under discussion. Financial support by EU18834AntiMal is acknowledge