Investigation of degradation mechanisms in low-voltage p-channel power MOSFETs under High Temperature Gate Bias stress

In this work we investigate the degradation mechanisms occurring in a p-channel trench-gate power MOSFET under High Temperature Gate Bias (HTGB) stress. The impact of negative bias temperature stress is analysed by evaluating relevant figures of merit for the considered device: threshold voltage, transconductance and on-resistance. Temperatures and gate voltages as large as 175 \ub0C and 1224 V, respectively, are adopted to accelerate the degradation in the device. Moreover, in order to investigate the origin of degradation mechanisms we analyse the interface states generation and the charge trapping processes, the impact of a switching gate voltage during the stress phase and the recovery phase after HTGB stress

Simplified on-line monitoring system of MOSFET on-resistance based on a semi-empirical model

This work provides a solution allowing to monitor on-line the health of a power MOSFET adopted in a buck converter. In the considered application, the analysis is focused on the high-side switch, being a low-voltage power MOSFET. The monitoring system allows estimating the on-resistance of the device by measuring both output current and voltage drop across the switch. Moreover, a semi-empirical model is considered in order to account for the dependence of the on-resistance on operating temperature and gate driving voltage. The on-line implementation of such a model allows estimating on-resistance degradation in real-time with a high level of accuracy in a wide range of operating conditions. An on-line calibration procedure is also implemented in order to assess the on-resistance of fresh devices. Experimental results confirm the accuracy of the system (in conjunction with the proposed model) under different operating conditions: load current from 2A to 6A; device temperature up to 100\ub0C and gate to source voltage (VGS) from 6V to 10.5V. In the abovementioned conditions, an accuracy 642.6% is experimentally found. Hence, the system is able to properly estimate the degradation of on-resistance due to ageing conditions

A Methodology to Account for the Finger Non-Uniformity in Photovoltaic Solar Cell

Abstract In this work we investigate the impact of a non-uniform finger in the front-side metallization on the performance of c-Si solar cells. For this purpose, we propose a methodology based on a mixed-mode simulation approach, which allows evaluating the solar cell properties by performing both numerical device simulations and circuit simulations. The finger roughness profile is modeled by means of Gaussian function. The impact of roughness on the solar cell efficiency is studied as a function of mean finger height, mean finger width and finger resistivity. The proposed methodology has been applied to typical roughness profiles realized with two different metallization techniques, the conventional single screen-printing (SP) and the double screen-printing (DP)

Experimental analysis of variability in WS2_2-based devices for hardware security

This work investigates the variability of tungsten disulfide (WS$_2$)-based devices by experimental characterization in view of possible application in the field of hardware security. To this aim, a preliminary analysis was performed by measurements across voltages and temperatures on a set of seven Si/SiO$_2$/WS$_2$ back-gated devices, also considering the effect of different stabilization conditions on their conductivity. Obtained results show appreciable variability in the conductivity, while also revealing similar dependence on bias and temperature across tested devices. Overall, our analysis demonstrates that WS$_2$-based devices can be potentially exploited to ensure adequate randomness and robustness against environmental variations and then used as building blocks for hardware security primitives

Surfactant behavior of sodium dodecylsulfate in deep eutectic solvent choline chloride/urea

Deep eutectic solvents (DES) resemble ionic liquids but are formed from an ionic mixture instead of being a single ionic compound. Here we present some results that demonstrate that surfactant sodium dodecyl sulfate (SDS) remains surface-active and shows self-assembly phenomena in the most commonly studied DES, choline chloride/urea. X-ray reflectivity (XRR) and small angle neutron scattering (SANS) suggest that the behavior is significantly different from that in water. Our SANS data supports our determination of the critical micelle concentration using surface-tension measurements and suggests that the micelles formed in DES do not have the same shape and size as those seen in water. Reflectivity measurements have also demonstrated that the surfactants remain surface-active below this concentration

Improving splenic conservation rate after trauma by applying a protocol for non-operative management and follow-up: A propensity-score analysis

Background: There are shared guidelines about Non-Operative Management (NOM) of splenic injuries, but some unanswered questions remain. The aim of the present study is to establish the usefulness of a standardized protocol for management and follow-up of NOM patients with splenic injuries. Methods: Multicenter retrospective observational study including patients with major blunt trauma (ISS.15) with splenic injuries managed between January 1st 2014 and December 31st 2016 in two Italian I level Trauma Centers: one with a standardized management and follow-up protocol for NOM (Bufalini Hospital, Cesena, BH), and the other without it (ASST Papa Giovanni XXIII Hospital, Bergamo, PG23H). Comparison between patients' outcomes were performed and a propensity score model was calculated. Results: 47 patients managed in BH and 49 patients in PG23H were included. In BH, a higher proportion of patients was treated with NOM (72.3 % vs. 53.1 %, p ¼ 0.051). There was no difference in complication rate and mortality in patients treated with NOM in the two hospitals. A borderline significant trend to a higher NOM failure rate in PG23H was found (BH 0.0 % vs. PG23H 11.3 %, p ¼ 0.076). The total splenic conservation rate was significantly higher in BH (BH 72.3 % vs. PG23H 46.9 %, p ¼ 0.011). After the Propensity Score based matching, 72 patients were included and the total splenic conservation rate was significantly higher in BH (BH: 77.8 % vs. PG23H: 50.9 %, p ¼ 0.014). Conclusions: The application of a protocol for in-hospital management and follow-up for NOM of patients with splenic injury could decrease the NOM failure rate and improve splenic conservation rate

An overview of the NIRSPEC upgrade for the Keck II telescope

NIRSPEC is a 1-5 micron echelle spectrograph in use on the Keck II Telescope since 1999. The spectrograph is capable of both moderate (R~2,000) and high (R~25,000) resolution observations and has been a workhorse instrument across many astronomical fields, from planetary science to extragalactic observations. In the latter half of 2018, we will upgrade NIRSPEC to improve the sensitivity and stability of the instrument and increase its lifetime. The major components of the upgrade include replacing the spectrometer and slit-viewing camera detectors with Teledyne H2RG arrays and replacing all transputer-based electronics. We present detailed design, testing, and analysis of the upgraded instrument, including the finalized optomechanical design of the new 1-5 micron slit-viewing camera, final alignment and assembly of the science array, electronics systems, and updated software design.Comment: Proceedings of the 2018 SPIE Astronomical Telescopes & Instrumentatio

MiR-200 family controls late steps of postnatal forebrain neurogenesis via Zeb2 inhibition

During neurogenesis, generation, migration and integration of the correct numbers of each neuron sub-Type depends on complex molecular interactions in space and time. MicroRNAs represent a key control level allowing the flexibility and stability needed f

Fungicidas foliares en soja, eficacia en el control de enfermedades y respuesta al rendimiento en tres localidades, norte de bs as y sur de Sta. fe. Campaña 2018/19

Entre las limitantes que presenta el cultivo de soja, se encuentran las llamadas enfermedades de fin de ciclo (EFC). En los últimos años, en la zona de Pergamino se destacaron por su prevalencia, incidencia y severidad la mancha marrón (Septoria glycines) y el tizón de la hoja y mancha púrpura de la semilla (Cercospora kikuchii, Cercospora spp.) (Distefano et al., 2017). Las EFC son causadas por hongos necrotróficos que sobreviven en semilla y rastrojo y afectan hojas, tallos, vainas y granos.EEA PergaminoFil: Couretot, Lucrecia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Fitopatología; ArgentinaFil: Pastore, M. CBAGRO (Consultora Agropecuaria); ArgentinaFil: Curti, A. Nueva Agronomía Chacabuco; ArgentinaFil: Angelotti, P. Nueva Agronomía Chacabuco; ArgentinaFil: Samoiloff, Anabella. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Fitopatología; ArgentinaFil: Magnone, Gerardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Fitopatología; ArgentinaFil: Russián, Hernan Darío. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Fitopatología; ArgentinaFil: Labatte, Matías. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Fitopatología; Argentin