H2_2 ortho-to-para conversion on grains: A route to fast deuterium fractionation in dense cloud cores?

Deuterium fractionation, i.e. the enhancement of deuterated species with respect to the non-deuterated ones, is considered to be a reliable chemical clock of star-forming regions. This process is strongly affected by the ortho-to-para (o-p) H$_2$ ratio. In this letter we explore the effect of the o-p H$_2$ conversion on grains on the deuteration timescale in fully depleted dense cores, including the most relevant uncertainties that affect this complex process. We show that (i) the o-p H$_2$ conversion on grains is not strongly influenced by the uncertainties on the conversion time and the sticking coefficient and (ii) that the process is controlled by the temperature and the residence time of ortho-H$_2$ on the surface, i.e. by the binding energy. We find that for binding energies in between 330-550 K, depending on the temperature, the o-p H$_2$ conversion on grains can shorten the deuterium fractionation timescale by orders of magnitude, opening a new route to explain the large observed deuteration fraction $D_\mathrm{frac}$ in dense molecular cloud cores. Our results suggest that the star formation timescale, when estimated through the timescale to reach the observed deuteration fractions, might be shorter than previously proposed. However, more accurate measurements of the binding energy are needed to better assess the overall role of this process.Comment: Accepted for publication in ApJ Letter

Private equity and venture capital markets in Europe

This review article provides a comprehensive outlook of the European Venture Capital and Private Equity markets. Venture Capital investments are a fundamental pillar for the future of European firms and European innovation. They are increasing at an unforeseen rate, leveraging on the unprecedented size of the resources available and the huge opportunities, as the ESG paradigm, arising in the continent. The literature entangling venture capital in Europe is relatively young. Nevertheless, Europe represents an excellent ground to test research ideas, as the venture capital markets considered are mature but rich in variety of specificities withi

Designing Distributed, Component-Based Systems for Industrial Robotic Applications

none3noneM. Amoretti; S. Caselli; M. ReggianiM., Amoretti; S., Caselli; Reggiani, Monic

Labour Market Power and the Quest for an Optimal Minimum Wage: Evidence from Italy

none3noThis study investigates the recent trends in labour market power in Italy and assesses the impact of a potential minimum wage using a large sample of manufacturing rms. We show that, despite an average shift of labour market power from the owners to the workers, monopsony power is still widespread, especially in some sectors and regions. The introduction of a minimum wage would be benecial to workers and the economy as it reduces the monopsony power of highly productive rms paying low wages; however, it may also have a negative impact, since rms with low wages and low labour productivity may react by reducing the number of their employees or even by exiting the market. Finally, we nd that an optimal minimum wage, which minimises the negative eect and maximises the positive eect for the economy, ranges between 8.25 and 9.65 euro per hour.openMauro Caselli; Jasmine Mondolo; Stefano SchiavoCaselli, Mauro; Mondolo, Jasmine; Schiavo, Stefan

An Ultra Low-Power Programmable Voltage Reference for Power-Constrained Electronic Systems

This paper proposes a novel architecture for the generation of a programmable voltage reference: the background- calibrated (BC)-PVR. Our mixed-signal architecture periodically calibrates a static ultra low-power voltage reference generator, from an accurate bandgap reference. The portion of the chip used for the calibration can be powered down with a programmable duty-cycle. The system aims to fully exploit the small temperature derivative vs time DT of several application domains to minimize the average current consumption. The BC-PVR has been designed and implemented in TSMC 55-nm CMOS technology, and it achieves the largest reported programming reference output ◦range [0.42 - 2.52] V, over the temperature range [-20 , 85] C. The duty-cycle mode allows nanoampere current consumption, and the large design flexibility permits to optimize the system performance for the specific application. These features make the BC-PVR very well-suited for power-constrained electronic systems

Efficient calibration of four wheel industrial AGVs

In this paper, we propose a novel method for extrinsic and intrinsic automatic calibration of four wheel industrial Automated Guided Vehicles (AGVs) compliant with Ackermann and Dual Drive kinematics. For each kinematic model the algorithm estimates the trajectories measured by an on-board sensor and the expected ones given the state of the wheels. The estimation exploits the model equations derived in this work which constrain calibration parameters and measurements from wheel encoders and sensor odometry. The parameter values are computed through closed-form solutions of least-square estimation. The method has been implemented on Programmable Logic Controllers and tested on industrial AGVs. The developed procedure computes the parameters in about 10−15 minutes, a significant improvement compared with one hour or more required by manual AGV calibration. Experiments with AGVs of various sizes in a warehouse have assessed the accuracy and stability of the proposed approach. The position accuracy achieved by AGVs calibrated with the proposed method is higher than the one achieved by manual calibration