50 research outputs found

    Modeling high-resolution climate change impacts on wheat and maize in Italy

    Get PDF
    Abstract The Mediterranean basin has been identified as a prominent hotspot of climate change, with expected negative impacts on crop productivity, among others. Given the primary role that agriculture has to sustain cultural values, economic opportunities, and food security, it is crucial to identify specific risks in agriculture due to climate change, which can address more effective adaptation strategies and policies to cope with climate change. This study aims to evaluate the high-resolution impacts of climate change on the length of the growing cycle and yield of durum wheat, common wheat, and maize in Italy by using the CERES-Wheat and CERES-Maize crop models implemented in the Decision Support System for Agrotechnology Transfer (DSSAT) software. A digital platform (GIS-DSSAT) was developed to couple crop simulation models with dynamically downscaled climate projections at high resolution for Italy, which can better represent the Italian landscape complexity and the spatial distribution of different pedological and crop management features, providing more detailed information on the expected impacts on crops respect to previous studies at a coarser resolution. The projections have been extended for two climate change scenarios and accounting for uncertainty, either considering or not the potential direct effects of increasing atmospheric CO2 concentrations ([CO2]). Results show that climate change may affect Italian cereal production in the medium to long term periods. Maize is the main affected crop, with yield reductions homogeneously distributed from North to South Italy. Wheat yield is expected to decrease mainly in southern Italy, while northern Italy may benefit from higher precipitation regimes. Higher levels of atmospheric CO2 concentrations may partially offset the negative impact posed by climate change and increase the benefits in the northern regions, especially for common and durum wheat

    Development of an Adaptive Model Predictive Control for Platooning Safety in Battery Electric Vehicles

    Get PDF
    The recent and continuous improvement in the transportation field provides several different opportunities for enhancing safety and comfort in passenger vehicles. In this context, Adaptive Cruise Control (ACC) might provide additional benefits, including smoothness of the traffic flow and collision avoidance. In addition, Vehicle-to-Vehicle (V2V) communication may be exploited in the car-following model to obtain further improvements in safety and comfort by guaranteeing fast response to critical events. In this paper, firstly an Adaptive Model Predictive Control was developed for managing the Cooperative ACC scenario of two vehicles; as a second step, the safety analysis during a cut-in maneuver was performed, extending the platooning vehicles’ number to four. The effectiveness of the proposed methodology was assessed for in different driving scenarios such as diverse cruising speeds, steep accelerations, and aggressive decelerations. Moreover, the controller was validated by considering various speed profiles of the leader vehicle, including a real drive cycle obtained using a random drive cycle generator software. Results demonstrated that the proposed control strategy was capable of ensuring safety in virtually all test cases and quickly responding to unexpected cut-in maneuvers. Indeed, different scenarios have been tested, including acceleration and deceleration phases at high speeds where the control strategy successfully avoided any collision and stabilized the vehicle platoon approximately 20–30 s after the sudden cut-in. Concerning the comfort, it was demonstrated that improvements were possible in the aggressive drive cycle whereas different scenarios were found in the random cycle, depending on where the cut-in maneuver occurred

    SAR evaluation of wireless antenna on implanted cardiac pacemaker

    Get PDF
    For many people, a pacemaker represents something scary because it is related to heart disease. However, that is not the main purpose of this paper, the object of the article is the technical aspect of pacemakers, in particular, their calculation of specific absorption rate values, to which the pacemaker is exposed. A pacemaker generates electrical discharges that are transferred into the heart via a lead wire and electrodes. Authors focus on the impact of Wi-Fi signal antennas on a pacemaker. A dipole antenna working in the frequency range around 5 GHz is chosen as a source of electromagnetic radiation because this kind of antennas is relatively new and it is not widely used yet. Nevertheless, it represents a potential for the future. The experiment is performed through electromagnetic simulation software called CST Microwave Studio that provides tools for SAR calculation and it allows to visualise the scatter of the resulting SAR values around the pacemaker or human torso. © 2017 Informa UK Limited, trading as Taylor & Francis Group.CZ.1.05/2.1.00/03.0089, ERDF, European Regional Development FundInternal Grant Agency of Tomas Bata University [IGA/CebiaTech/2016/005]; Ministry of Education, Youth and Sports of the Czech Republic [LO1303 (MSMT-7778/2014)]; European Regional Development Fund [CZ.1.05/2.1.00/03.0089

    Conformation-based Molecular Memories for Nanoscale MemComputing

    Get PDF
    We investigate the use of endohedral fullerenes and 6-(Ferrocenyl)hexanethiol cation as molecular non-volatile memory devices. We demonstrate stable encoding of the information in the geometry and dipole moment of these molecules. The write operation can be performed with external programming electric fields that drive the switching of the molecule conformation. The read operation can be performed by reading the dipole moment through the generated electric fields. Moreover, the dipole moment encoding enables the integration of proposed memories with molecular Field-Coupled Nanocomputing logic. The capability to realize compatible and purely molecular memory and logic devices paves the way for molecular MemComputing, with new possibilities for nanoscale computing paradigms

    Design of Pyrrole-Based Gate-Controlled Molecular Junctions Optimized for Single-Molecule Aflatoxin B1 Detection

    Get PDF
    Food contamination by aflatoxins is an urgent global issue due to its high level of toxicity and the difficulties in limiting the diffusion. Unfortunately, current detection techniques, which mainly use biosensing, prevent the pervasive monitoring of aflatoxins throughout the agri-food chain. In this work, we investigate, through ab initio atomistic calculations, a pyrrole-based Molecular Field Effect Transistor (MolFET) as a single-molecule sensor for the amperometric detection of aflatoxins. In particular, we theoretically explain the gate-tuned current modulation from a chemical–physical perspective, and we support our insights through simulations. In addition, this work demonstrates that, for the case under consideration, the use of a suitable gate voltage permits a considerable enhancement in the sensor performance. The gating effect raises the current modulation due to aflatoxin from 100% to more than 103÷104 %. In particular, the current is diminished by two orders of magnitude from the μA range to the nA range due to the presence of aflatoxin B1. Our work motivates future research efforts in miniaturized FET electrical detection for future pervasive electrical measurement of aflatoxins

    NS-GAAFET Compact Modeling: Technological Challenges in Sub-3-nm Circuit Performance

    Get PDF
    NanoSheet-Gate-All-Around-FETs (NS-GAAFETs) are commonly recognized as the future technology to push the digital node scaling into the sub-3 nm range. NS-GAAFETs are expected to replace FinFETs in a few years, as they provide highly electrostatic gate control thanks to the GAA structure, with four sides of the NS channel entirely enveloped by the gate. At the same time, the NS rectangular cross-section is demonstrated to be effective in its driving strength thanks to its high saturation current, tunable through the NS width used as a design parameter. In this work, we develop a NS-GAAFET compact model and we use it to link peculiar single-device parameters to digital circuit performance. In particular, we use the well-known BSIM-CMG core solver for multigate transistors as a starting point and develop an ad hocresistive and capacitive network to model the NS-GAAFET geometrical and physical structure. Then, we employ the developed model to design and optimize a digital inverter and a five-stage ring oscillator, which we use as a performance benchmark for the NS-GAAFET technology. Through Cadence Virtuoso SPICE simulations, we investigate the digital NS-GAAFET performance for both high-performance and low-power nodes, according to the average future node present in the International Roadmap for Devices and Systems. We focus our analysis on the main different technological parameters with regard to FinFET, i.e., the inner and outer spacers. Our results highlight that in future technological nodes, the choice of alternative low-K dielectric materials for the NS spacers will assume increasing importance, being as relevant, or even more relevant, than photolithographic alignment and resolution at the sub-nm scale

    Single-molecule Aflatoxin B1 Sensing via Pyrrole-based Molecular Quantum Dot

    Get PDF
    We investigate through ab-initio simulations the gold-8PyrroleDiThiol-gold (Au-8PyDT) molecular quantum dot as an amperometric single-molecule sensor for the aflatoxin B1 (AFB1) detection. We study the adsorption of AFB1 onto the Au-8PyDT and we analyze the transport characteristics for the most probable adsorption configuration. We find that a significant current modulation occurs, with around 80% of current decrease in presence of AFB1. Interestingly, the investigated sensor exhibits a voltage-dependent response, that we motivate through a transmission properties analysis. Our results, considering the synthesis simplicity of PolyPyrroles and their non-toxicity, motivate future research efforts in this direction

    Electronic Transport Study of Bistable Cr@C28 Single-Molecule Device for High-Density Data Storage Applications

    Get PDF
    We investigate through ab initio calculation the endohedral monometallofullerene Cr@C28 as a candidate for data storage applications. First, we study the encapsulation energy and the electronic properties of two stable states of the Cr@C28 - namely I-Cr@C28 and II-Cr@C28. Then, we address the adsorption of C28, I-Cr@C28, and II-Cr@C28 onto a gold substrate. Finally, by emulating a Scanning Tunneling Microscope (STM) break-junction experimental setup, we analyze the STM-mediated transport characteristics for the most probable adsorption configurations. We find and discuss a significant and measurable current difference between the two stable states. This outcome enables the binary encoding of the information, making the proposed device promising as a single-molecule data storage element for future high-density integrated circuits

    Tunnel Field-Effect Transistor: Impact of the Asymmetric and Symmetric Ambipolarity on Fault and Performance in Digital Circuits

    Get PDF
    Tunnel Field-Effect Transistors (TFETs) have been considered one of the most promising technologies to complement or replace CMOS for ultra-low-power applications, thanks to their subthreshold slope below the well-known limit of 60 mV/dec at room temperature holding for the MOSFET technologies. Nevertheless, TFET technology still suffers of ambipolar conduction, limiting its applicability in digital systems. In this work, we analyze through SPICE simulations, the impact of the symmetric and asymmetric ambipolarity in failure and power consumption for TFET-based complementary logic circuits. Our results clarify the circuit-level effects induced by the ambipolarity feature, demonstrating that it affects the correct functioning of logic gates and strongly impacts power consumption. We believe that our outcomes motivate further research towards technological solutions for ambipolarity suppression in TFET technology for near-future ultra-low-power application

    Autochthonous fermentation starters for the industrial production of Negroamaro wines

    Get PDF
    Abstract The aim of the present study was to establish a new procedure for the oenological selection of Saccharomyces cerevisiae strains isolated from natural must fermentations of an important Italian grape cultivar, denoted as "Negroamaro". For this purpose, 108 S. cerevisiae strains were selected as they did not produce H2S and then assayed by microfermentation tests. The adopted procedure made it possible to identify 10 strains that were low producers of acetic acid and hydrogen sulphide and showed that they completed sugar consumption during fermentation. These strains were characterized for their specific oenological and technological properties and, two of them, strains 6993 and 6920, are good candidates as industrial starter cultures. A novel protocol was set up for their biomass production and they were employed for industrial-scale fermentation in two industrial cellars. The two strains successfully dominated the fermentation process and contributed to increasing the wines' organoleptic quality. The proposed procedure could be very effective for selecting "company-specific" yeast strains, ideal for the production of typical regional wines. "Winery" starter cultures could be produced on request in a small plant just before or during the vintage season and distributed as a fresh liquid concentrate culture
    corecore