34 research outputs found
Fattori di Rischio umani e infortuni conseguenti agli incidenti stradali: analisi di dati correnti
No full textObiettivo: molte ricerche dimostrano che la maggior parte degli incidenti stradali sono causati dall’errore umano legato in particolar modo all’età e al sesso. Questo studio vuole verificare il ruolo di alcuni fattori umani nell’incidentalità stradale rilevata attraverso le registrazioni correnti in un’area definita, la Provincia di Pavia.
Disegno: integrare l’archivio cartaceo, opportunamente informatizzato, dei verbali degli incidenti stradali compilati dall’autorità di polizia presenti presso l’Ufficio provinciale della motorizzazione civile e il database del 118 provinciale e dei reparti di pronto soccorso della Provincia di Pavia e del registro di mortalità ASL. Analisi degli incidenti stradali occorsi nell’anno 2004. Si sono analizzati 1.347 incidenti per un totale di 2.908 conducenti di veicoli motorizzati coinvolti.
Setting: Provincia di Pavia.
Risultati: il tasso di mortalità dei conducenti dei veicoli a due ruote è quasi nove volte quello dei conducenti dei mezzi a quattro ruote. L’analisi logistica mostra un rischio di subire conseguenze doppio del sesso femminile, il ruolo protettivo di un maggior training di educazione stradale e il ruolo protettivo dell’età nella classe da 30 a 64 anni che cresce ulteriormente nella classe di conducenti con età maggiore di 64 anni. Chi ha ricevuto una decurtazione dei punti sulla patente presenta una probabilità più alta di non riportare conseguenze nello scontro riuscendo probabilmente a porre in atto azioni di difesa più rapidamente di chi le subisce. Inoltre, risulta che i guidatori dei veicoli a due ruote hanno un rischio circa 25 volte maggiore di rimanere infortunati rispetto a quelli dei mezzi a quattro ruote. Per quanto concerne la gravità delle conseguenze tra gli infortunati, l’unico fattore umano significativo è il sesso, che conferma un rischio maggiore nelle donne di circa il 40% rispetto agli uomini di rimanere ferite gravemente. Si conferma anche in questo caso il maggior rischio di riportare gravi conseguenze nei veicoli a due ruote rispetto a quelli a quattro ruote.
Conclusione: le evidenze che emergono portano a rischi maggiori di infortunio i conducenti femmine, i veicoli a due ruote, chi non commette l’infrazione e i conducenti giovani. In base alle evidenze emerse pensiamo che questo studio possa essere una base di partenza per ricavare informazioni utili per interventi di prevenzione
Understanding and Optimization of Hot-Carrier Reliability in Germanium-on-Silicon pMOSFETs
No full textOxypoda (Thliboptera) attenuata MULSANT & REY 1853
No full textOxypoda (Thliboptera) attenuata MULSANT & REY 1853 (Fig. 2, Map 2) Oxypoda attenuata MULSANT & REY 1853: 53 ff. Oxypoda micans KRAATZ 1855: 331 f.; resyn. Oxypoda luctifera var. rufonitens PEYERIMHOFF 1901: 63. Type material examined O. micans: Lectotype [dissected prior to present study]: "micans mihi, Graec. v. Ksw. / Coll. Kraatz / Holotypus / Lectotypus Oxypoda micans Kraatz, 1856, Zerche desg. 1993 / DEI Müncheberg Col-02784 / Oxypoda attenuata Mulsant & Rey, det. V. Assing 2012" (SDEI). Additional material examined: Greece: 4 exs., N Larissa, Kato Olympos, above Goni, 39°54'N, 22°27'E, 550 m, road margin, in nest of Messor sp., 6.IV.1998, leg. Assing (cAss); 4 exs., Kato Olympos, E Kallipefki, 39°58'N, 22°29'E, 1500-1580 m, 6.IV.1998, leg. Assing (cAss); 1 ex., Fthiotis, 30 km W Lamia, W Kalithea, 38°53'N, 22°06'E, 800 m, oak forest, sifted, 16.IV.2000, leg. Assing (cAss); 1, Makedhonía, NW Kavála, Pangéo, beech forest near ski resort, 1650 m, 24.V.1999, leg. Assing (cAss); 1 ex., Pelopónnisos, Agios Nikolaos, IV.1999, leg. Wachtel (cAss); 12 exs., Levkas, Vouno peak, 1050 m, sifted, 25.IX.1993, leg. Assing (cAss); 2 exs., Ikaria, Nas, 37°37'N, 26°03'E, 10-100 m, stream valley, Mastix litter sifted, 26.IV.2003, leg. Brachat & Meybohm (cAss). Italy: 1, Sardinia, Cat. d. Marghine, Mt. Palai, 1000 m, leaf litter sifted, 12.X.1989, leg. Wunderle [" Oxypoda attenuata M. et R., Zerche det. 1992, LT Lyon, cum typ. comp., Zerche 1992"] (cWun); 1, Monti del Gennargentu, Brunco Spina, 40°01'N, 09°18'E, 1700 m, edge of snowfield, sifted, 12.V.2005, leg. Hetzel (cFel); 1, Monti del Gennargentu, Punta la Marmora, 40°01'N, 09°17'E, 1600 m, 16.V.2005, leg. Hetzel (cAss). Morocco: 6 exs., Haut Atlas, NE Tizi-n-Test, 30°52'N, 8°22'W, 2070 m, Quercus ilex forest, sifted, 26.XII.2002, leg. Assing, Wunderle (cAss, cWun); 5 exs., Khénifra, lake Aguelmane, Azizga, under rocks near lakeshore, 10.V.2009, leg. Hlavá (cAss); 2 exs., Moyen Atlas, Azrou env., Forêt de Cedres, 33°43'N, 5°18'W, 1600 m, sifted, 9.V.2009, leg. Hlavá (cAss). Comment: Oxypoda attenuata was described from an unspecified number of syntypes from "Hyères" (MULSANT & REY 1953). Three type specimens were examined and a lectotype was designated by ZERCHE (1994). The original description of O. micans is based on an unspecified number of syntypes from " Griechenland " collected by "Herrn von Kiesenwetter" (KRAATZ 1855). A single female is deposited in the Kraatz collection at the SDEI. In referring to this specimens as " Holotypus " GAEDIKE (1981) designated it as the lectotype. It has a lectotype label by L. Zerche attached to it, but his designation was never published. Most species of Thliboptera can reliably be identified and interpreted only based on the morphology of the aedeagus. Therefore, the female lectotype is hypothesised to be conspecific with the most common representative of the subgenus in Greece. Oxypoda micans was synonymised with O. attenuata by BERNHAUER (1902) and revalidated by ZERCHE (1994), who stated that it was "eine distinkte und allopatrisch verbreitete Art" without providing evidence. Oxypoda micans was previously known only from Greece and Turkey (ASSING 2006a, 2007a; SMETANA 2004). The external and sexual characters of the specimens from Morocco (see above) are practically identical to those of the material seen from Greece and Turkey. The same is true of the specimens seen from Sardinia. Slight differences between these populations may be observed in the length of the apical part of the ventral process of the median lobe and in the size of the crista apicalis of the aedeagus, as well as in body size. However, these differences are barely noticeable and, at the same time, there is some variation of these characters even with populations. Moreover, a remarkably discontinuous distribution, as it is currently known (Map 2), would seem as unlikely as the possibility that this species has never been found in the region between Greece, Sardinia, and Morocco. The only plausible explanation, therefore, is that populations from other regions have been recorded under a different name. The most likely candidate would be O. attenuata MULSANT & REY 1853, which has been reported from North Africa (Algeria) and in southern Europe from Spain to Greece (SMETANA 2004). Unfortunately, the type material of O. attenuata is teneral, in poor condition, and the aedeagus figured by ZERCHE (1994) is evidently deformed. In consequence, based on the available evidence, O. micans and O. attenuata are hypothesised to be conspecific and the former is placed in synonymy with the latter. For additional records from Turkey see ASSING (2007a). According to PEYERIMHOFF (1901), O. rufonitens represents a variety of O. luctifera distributed in the French Alps and the Provence. At present, this treated as a synonym of O. luctifera. Confirmed records of O. luctifera have become known only from Algeria, so that O. rufonitens is most likely a synonym of O. attenuata, which was described from southeastern France. Oxypoda attenuata was previously attributed to the subgenus Podoxya MULSANT & REY 1875. It is here transferred to the subgenus Thliboptera. For an illustration of the aedeagus (as O. micans) see ASSING (2006a). The aedeagus of a male from Sardinia is illustrated in Fig. 2. The distribution is shown in Map 2.Published as part of Assing, V., 2012, On the taxonomy and zoogeography of some Oxypoda species of the West Palaearctic region (Coleoptera: Staphylinidae: Aleocharinae), pp. 365-399 in Linzer biologische Beiträge 44 (1) on pages 371-372, DOI: 10.5281/zenodo.532744
Ge and III/V devices for advanced CMOS
No full textThe use of Ge and III/V materials for future CMOS applications is investigated. Good passivation of the Ge surface can be obtained by either GeO2 or Si passivation. Short channel Ge pMOS devices with low EOT are fabricated using Si passivation at 350 and 500 degrees C. The passivation of III/V materials is a very challenging topic. Some critical issues and passivation schemes are discussed
Performance enhancements in scaled strained-SiGe pMOSFETs with HfSiOx/TiSiN gate stacks
Get PDFThe short-channel performance of compressively strained Si0.77Ge0.23 pMOSFETs with HfSiOx/TiSiN gate stacks has been characterized alongside that of unstrained-Si pMOSFETs. Strained-SiGe devices exhibit 80% mobility enhancement compared with Si control devices at an effective vertical field of 1 MV middotcm-1. For the first time, the on-state drain-current enhancement of intrinsic strained-SiGe devices is shown to be approximately constant with scaling. Intrinsic strained-SiGe devices with 100-nm gate lengths exhibit 75% enhancement in maximum transconductance compared with Si control devices, using only ~20% Ge (~0.8% strain). The origin of the loss in performance enhancement commonly observed in strained-SiGe devices at short gate lengths is examined and found to be dominated by reduced boron diffusivity and increased parasitic series resistance in compressively strained SiGe devices compared with silicon control devices. The effective channel length was extracted from I- V measurements and was found to be 40% smaller in 100-nm silicon control devices than in SiGe devices having the same lithographic gate lengths, which is in good agreement with the metallurgical channel length predicted by TCAD process simulations. Self-heating due to the low thermal conductivity of SiGe is shown to have a negligible effect on the scaled-device performance. These findings demonstrate that the significant on-state performance gains of strained-SiGe pMOSFETs compared with bulk Si devices observed at long channel lengths are also obtainable in scaled devices if dopant diffusion, silicidation, and contact modules can be optimized for SiGe
Fabrication and characterisation of novel Ge MOSFETs
Get PDFAs high-k dielectrics are introduced into commercial Si CMOS (Complimentary Metal Oxide Semiconductor) microelectronics, the 40 year channel/dielectric partnership of Si/SiO2 is ended and the door opened for silicon to be replaced as the active channel material in MOSFETs (Metal Oxide Semiconductor Field Effect Transistor). Germanium is a good candidate as it has higher bulk carrier mobilities than silicon. In addition, Si and Ge form a thermodynamically stable SiGe alloy of any composition, allowing Ge to be implemented as a thin layer on the surface of a standard Si substrate. This thesis is a practical investigation on several aspects of Ge CMOS technology.
High-k dielectric Ge p-MOSFETs are electrically characterised. A large variation in interface state densities is demonstrated to be responsible for a threshold voltage shift and this is proportional to reciprocal peak mobility due to the Coulomb scattering of carriers by charged states. A theoretical mobility is fitted to that measured at 4.2 K and confirms that interface states are the main source of interface charged impurities.
The model demonstrates a reduction in the interface charged impurity density in p-MOSFETs that underwent a PMA (Post Metallisation Anneal) in hydrogen atmosphere and that the anneal also reduces the RMS (Root Mean Square) dielectric/semiconductor interface roughness, from an average of 0.60 nm to 0.48 nm.
High-k strained Ge p-MOSFETs are electrically characterised and have peak mobilities at 300 K (470 cm2 V-1 s-1) and 4.2 K (1780 cm2 V-1 s-1) far in excess of those measured for the unstrained Ge p-MOSFETs (285 cm2 V-1 s-1,785 cm2 V-1 s-1 respectively). Strained Ge n-MOSFETs perform significantly worse than standard Si P, - MOSFETs primarily due to a high source/drain resistance.
A 10 nm thick SiGe-01 (On Insulator) layer with a Ge composition of 58% is obtained from a 55 nm Si0_88Ge1o2. initial layer on 100 nm Si-Ol substrate via the germanium condensation technique. For the first time, germanium is demonstrated to diffuse through the BOX (Buried OXide) during Ge-condensation and into the underlying Si substrate. An order of magnitude increase in the calculated ITOX (Internal Thermal OXidation) rate of the BOX in the final stages of Ge-condensation is hypothesised to be responsible for stopping this diffusion
Atomic Layer Deposition of High-kappa Dielectric Layers on Ge and III-V MOS Channels
No full textGe and III-V semiconductors are potential high performance channel materials for future CMOS devices. In this work, we have studied Atomic Layer Deposition (ALD) of high-kappa dielectric layers oil Ge and GaAs Substrates. We focus at the effect of the oxidant (H2O, O-3, O-2, O-2 plasma) during gate stack formation. GeO2, obtained by Ge oxidation in O-2 or O-3, is a promising passivation layer. The germanium oxide thickness call be scaled down below I nm, but Such thin layers contain Ge ill oxidation states lower than 4+. Still, electrical results indicate that small amounts of Ge in oxidation states lower than 4+ are not detrimental for device performance. Partial intermixing was observed for high-kappa dielectric and GeO2 or GaAsOx, suggesting possible correlations ill the ALD growth mechanisms oil Ge and GaAs substrates.European CommissionEuropean Commission Joint Research Centre [214579
Germanium Partitioning and Interface Stability During Rapid Solidification of Gesi Alloys
No full textAbstractThe stability of laser processed GeSi heteroepitaxial alloys on Si to partitioning driven interface instabilities is examined. Existing stability models are extended to include nonequi-librium solidification effects for nondilute alloys and are examined under typical conditions of laser induced solidification. Ge diffusion and partitioning were measured for quantitative input to the models. The Ge liquid-phase diffusivity was determined to be 2.5 x 10-4 cm2/s. The measured velocity-dependent partition coefficients k(v) were fit to the Continuous Growth Model using an equilibrium k of 0.45 and a diffusive speed of 2.7 m/s. Stability calculations based on these values and our extended stability model are presented. Although instabilities at compositions comparable to those experimentally observed to give defective films are predicted, the growth rates of these instabilities appear too slow to destabilize an interface on laser processing time scales. These results suggest that strain or other effects play an important role in the observed defective microstructures.</jats:p
Quantum well band calculations and their impact on device isolation and work function requirements for SiGe and III/V strained heterostructure FinFETs
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