المؤلفون: Di Palma, L., Albo, G., Nardone, M., Pezzella, C., Musella, V., Belardo, M.

المصدر: Journal of Physics: Conference Series ; volume 2716, issue 1, page 012023 ; ISSN 1742-6588 1742-6596

الوصف: The T-WING project is a research project aimed at designing, manufacturing, qualifying and testing the new wing of Leonardo Next Generation Civil Tilt-Rotor technical demonstrator (NGCTR-TD), as part of Clean Aviation Fast Rotorcraft activities. The methodology proposed in this paper encompasses the development of high-fidelity modelling and simulation procedures in support to virtual certification methods for crashworthiness requirements of tiltrotors. Finite Element Analysis (FEA) of an aircraft drop test is a complex and detailed process that aims to simulate the structural behaviour during an impact or drop event. This type of analysis is critical for assessing the safety of an aircraft in emergency landing situations. Wing crashworthiness requirement is specific for tilt rotors: during a survivable crash event, the wing design must ensure a pre-defined rupture with the purpose of alleviating the inertial load acting on the fuselage to preserve the occupants from injuries and fire, guaranteeing the escape paths. Thus, the highly integrated T-WING wing box concept has been designed with the specific feature of frangible sections near the wing-fuselage intersection. The activation of fracture of the external semi-wings in correspondence of frangible section is triggered by the achievement of a well-defined crash vertical load factor. The objective of the methodology is to simulate the crash effects on the whole wing, using explicit non-linear and time-dependent FE analysis, to verify the wing spanwise placement of the frangible sections, the failure mode, the loads acting at the fuselage links, and the acceleration transmitted to the structure. This work is focused on a standalone analysis of the wing plus a lumped scheme of the fuselage, and it is part of a wider activity which will comprise, in the crash simulation, the most relevant vehicle systems (e.g. fuselage model). Moreover, this numerical activity has been compared with experimental results obtained on a different but similar structure, in ...

الإتاحة: https://doi.org/10.1088/1742-6596/2716/1/012023Test

المؤلفون: Iglesias, José M, Nardone, Alejandra, Rengel, Raúl, Kalna, Karol, Martín, María J, Pascual, Elena

المصدر: 2D Materials ; volume 10, issue 2, page 025011 ; ISSN 2053-1583

الوصف: The effect of degeneracy and the impact of free-carrier screening on a low-field mobility and a high-field drift velocity in MoS 2 and WS 2 are explored using an in-house ensemble Monte Carlo simulator. Electron low field mobility increases to 8400 c m 2 V − 1 s − 1 for MoS 2 and to 12 040 c m 2 V − 1 s − 1 for WS 2 when temperature decreases to 77 K and carrier concentration is around 5 × 10 12 c m − 2 . In the case of holes, best mobility values were 9 320 c m 2 V − 1 s − 1 and 13 290 c m 2 V − 1 s − 1 , reached at similar temperature and carrier concentration conditions while at room temperature these fall to 80 c m 2 V − 1 s − 1 and 150 c m 2 V − 1 s − 1 for MoS 2 and WS 2 , respectively. The carrier screening effect plays a major role at low fields, and low and intermediate temperatures, where a combination of large occupancy of primary valleys and carrier–phonon interactions dominated by relatively low energy exchange processes results in an enhanced screening of intrinsic scattering. For electrons, degeneracy yields to transport in secondary valleys, which plays an important role in the decrease of the low field mobility at high concentrations and/or at room temperature. The high-field drift velocity is not much affected by carrier screening because of an increased carrier scattering with surface optical polar phonons, favouring larger phonon wavevector interactions with small dielectric function values.

الإتاحة: https://doi.org/10.1088/2053-1583/acb1c2Test

المؤلفون: José M Iglesias, Alejandra Nardone, Raúl Rengel, Karol Kalna, María J Martín, Elena Pascual

المصدر: 2D Materials. 10:025011

مصطلحات موضوعية: Mechanics of Materials, Mechanical Engineering, General Materials Science, General Chemistry, Condensed Matter Physics

الوصف: The effect of degeneracy and the impact of free-carrier screening on a low-field mobility and a high-field drift velocity in MoS2 and WS2 are explored using an in-house ensemble Monte Carlo simulator. Electron low field mobility increases to 8400 c m 2 V − 1 s − 1 for MoS2 and to 12 040 c m 2 V − 1 s − 1 for WS2 when temperature decreases to 77 K and carrier concentration is around 5 × 10 12 c m − 2 . In the case of holes, best mobility values were 9 320 c m 2 V − 1 s − 1 and 13 290 c m 2 V − 1 s − 1 , reached at similar temperature and carrier concentration conditions while at room temperature these fall to 80 c m 2 V − 1 s − 1 and 150 c m 2 V − 1 s − 1 for MoS2 and WS2, respectively. The carrier screening effect plays a major role at low fields, and low and intermediate temperatures, where a combination of large occupancy of primary valleys and carrier–phonon interactions dominated by relatively low energy exchange processes results in an enhanced screening of intrinsic scattering. For electrons, degeneracy yields to transport in secondary valleys, which plays an important role in the decrease of the low field mobility at high concentrations and/or at room temperature. The high-field drift velocity is not much affected by carrier screening because of an increased carrier scattering with surface optical polar phonons, favouring larger phonon wavevector interactions with small dielectric function values.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ae4f80b02a6497b5bf9d6fa6f7e42b49Test
https://doi.org/10.1088/2053-1583/acb1c2Test

المؤلفون: Causa, F, Gittini, G, Minelli, D, Mellera, V, Uccello, A, Nardone, A, Ripamonti, F

المصدر: Plasma Sources Science and Technology ; volume 31, issue 7, page 075007 ; ISSN 0963-0252 1361-6595

الوصف: Determining plasma parameters in low-density, low-temperature, weakly ionized, magnetised plasmas can be challenging, especially when using in-house-built Langmuir probes that may perturb the plasma. Radial profiles along the plasma column in such conditions present further challenges, not only because the densities evanesce at the edges, but also because of the presence of magnetic fields that may significantly affect the measurements. The analysis is presented here of radial profiles in pure argon and pure helium plasmas obtained using in-house-built Langmuir probes. The study was done in detail not only to obtain plasma parameter profiles, but also to gain an insight into the relevant physical mechanisms in the operating conditions of interest. Results from a plasma model were used to complement the analysis together with qualitative observations from resulting electron energy distribution functions. The main conclusions are: profiles obtained with the plasma model closely represent those obtained from Langmuir probe data, with irregularities qualitatively explained using electron density profiles obtained with Druyvesteyn and first derivative methods; plasma densities and electron currents are sufficiently small that no diamagnetic effects are evident; the strong magnetisation of the electrons is evident from the resulting characteristic Bessel-type density profiles.

الإتاحة: https://doi.org/10.1088/1361-6595/ac8018Test

المؤلفون: Bin, W., Bruschi, A., D'Arcangelo, O., Castaldo, C., Angeli, M. De, Figini, L., Galperti, C., Garavaglia, S., Granucci, G., Grosso, G., Korsholm, S.B., Lontano, M., Mellera, V., Minelli, D., Moro, A., Nardone, A., Nielsen, S.K., Rasmussen, J., Simonetto, A., Stejner, M., Tartari, U.

المصدر: Journal of Instrumentation ; volume 10, issue 10, page P10007-P10007 ; ISSN 1748-0221

الإتاحة: https://doi.org/10.1088/1748-0221/10/10/p10007Test
http://stacks.iop.org/1748-0221/10/i=10/a=P10007/pdfTest
http://stacks.iop.org/1748-0221/10/i=10/a=P10007?key=crossref.68b7032895045a15533ca8ec5cc7fd2fTest

المؤلفون: F Causa, G Gittini, D Minelli, V Mellera, A Uccello, A Nardone, F Ripamonti

المصدر: Plasma Sources Science and Technology. 31:075007

مصطلحات موضوعية: Condensed Matter Physics

الوصف: Determining plasma parameters in low-density, low-temperature, weakly ionized, magnetised plasmas can be challenging, especially when using in-house-built Langmuir probes that may perturb the plasma. Radial profiles along the plasma column in such conditions present further challenges, not only because the densities evanesce at the edges, but also because of the presence of magnetic fields that may significantly affect the measurements. The analysis is presented here of radial profiles in pure argon and pure helium plasmas obtained using in-house-built Langmuir probes. The study was done in detail not only to obtain plasma parameter profiles, but also to gain an insight into the relevant physical mechanisms in the operating conditions of interest. Results from a plasma model were used to complement the analysis together with qualitative observations from resulting electron energy distribution functions. The main conclusions are: profiles obtained with the plasma model closely represent those obtained from Langmuir probe data, with irregularities qualitatively explained using electron density profiles obtained with Druyvesteyn and first derivative methods; plasma densities and electron currents are sufficiently small that no diamagnetic effects are evident; the strong magnetisation of the electrons is evident from the resulting characteristic Bessel-type density profiles.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a3ff8c268c623abcadf06a5dd7d3d0feTest
https://doi.org/10.1088/1361-6595/ac8018Test

المؤلفون: Polignano, M L, Russo, F, Moccia, G, Nardone, G

المصدر: Semiconductor Science and Technology ; volume 35, issue 12, page 124003 ; ISSN 0268-1242 1361-6641

الوصف: We have analysed the effects of intentional metal contamination on the dark current of complementary metal-oxide-semiconductor image sensors. A few contaminants (molybdenum, tungsten, vanadium, titanium, copper) have been selected for this study, because they previously showed the most relevant impact on the dark current. The dependence of the dark current on temperature has been analysed in contaminated diodes from different regions of the dark current distribution. The generation current is always dominant in the diodes contaminated with the metals in this study, whether diodes in the peak of the distribution or in high current tails are considered. Diodes contaminated with slow diffusers never deviate from a diffusion-generation model of the current vs temperature. Copper contaminated diodes are the only example showing a limited but significant contribution approximately independent of temperature, which can be ascribed to a local tunnel current due to copper precipitates. From the point of view of dark current spectroscopy, this analysis shows that a correct identification of the dominant impurity is more easily obtained if diodes in the peak region of the dark current distribution are analysed. Indeed, in these diodes the generation current is characterized by an energy level which is a fingerprint of the dominant impurity. Vice versa, in high current diodes the dominant energy level can be different from this level, though the generation current is even more important in these diodes.

الإتاحة: https://doi.org/10.1088/1361-6641/abb840Test

المؤلفون: Palleschi, S, D’Olimpio, G, Benassi, P, Nardone, M, Alfonsetti, R, Moccia, G, Renzelli, M, Cacioppo, O A, Hichri, A, Jaziri, S, Politano, A, Ottaviano, L

المصدر: 2D Materials ; volume 7, issue 2, page 025001 ; ISSN 2053-1583

الإتاحة: https://doi.org/10.1088/2053-1583/ab5bf8Test

المؤلفون: Vanacken, J, Frings, P, Detlefs, C, Duc, F, Lorenzo, J E, Nardone, M, Billette, J, Zitouni, A, Bras, W, Rikken, G

المصدر: Journal of Physics: Conference Series ; volume 51, page 475-482 ; ISSN 1742-6588 1742-6596

الإتاحة: https://doi.org/10.1088/1742-6596/51/1/109Test
http://stacks.iop.org/1742-6596/51/i=1/a=109/pdfTest

المؤلفون: Felice Russo, G. Nardone, G. Moccia, Maria Luisa Polignano

المصدر: Semiconductor Science and Technology. 35:124003

مصطلحات موضوعية: Materials science, Distribution (number theory), business.industry, Metal contaminants, Contamination, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, CMOS, Materials Chemistry, Optoelectronics, Electrical and Electronic Engineering, Image sensor, business, Dark current

الوصف: We have analysed the effects of intentional metal contamination on the dark current of complementary metal-oxide-semiconductor image sensors. A few contaminants (molybdenum, tungsten, vanadium, titanium, copper) have been selected for this study, because they previously showed the most relevant impact on the dark current. The dependence of the dark current on temperature has been analysed in contaminated diodes from different regions of the dark current distribution. The generation current is always dominant in the diodes contaminated with the metals in this study, whether diodes in the peak of the distribution or in high current tails are considered. Diodes contaminated with slow diffusers never deviate from a diffusion-generation model of the current vs temperature. Copper contaminated diodes are the only example showing a limited but significant contribution approximately independent of temperature, which can be ascribed to a local tunnel current due to copper precipitates. From the point of view of dark current spectroscopy, this analysis shows that a correct identification of the dominant impurity is more easily obtained if diodes in the peak region of the dark current distribution are analysed. Indeed, in these diodes the generation current is characterized by an energy level which is a fingerprint of the dominant impurity. Vice versa, in high current diodes the dominant energy level can be different from this level, though the generation current is even more important in these diodes.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::608a868ed016c98a02002f70d688bf5fTest
https://doi.org/10.1088/1361-6641/abb840Test