Search results for "Figur"
showing 10 items of 1122 documents
A theory ofnonverticaltriplet energy transfer in terms of accurate potential energy surfaces: The transfer reaction from π,π* triplet donors to 1,3,5…
2004
Triplet energy transfer (TET) from aromatic donors to 1,3,5,7-cyclooctatetraene (COT) is an extreme case of "nonvertical" behavior, where the transfer rate for low-energy donors is considerably faster than that predicted for a thermally activated (Arrhenius) process. To explain the anomalous TET of COT and other molecules, a new theoretical model based on transition state theory for nonadiabatic processes is proposed here, which makes use of the adiabatic potential energy surfaces (PES) of reactants and products, as computed from high-level quantum mechanical methods, and a nonadiabatic transfer rate constant. It is shown that the rate of transfer depends on a geometrical distortion paramet…
La Prima Guerra Mondiale nella cultura figurativa siciliana
2019
Nel volume "Dalla memoria del sacrificio alla celebrazione della Vittoria. La Prima Guerra Mondiale nella cultura artistica e architettonica siciliana", il contributo presenta una ricognizione sulla cultura figurativa in Sicilia durante la Prima Guerra Mondiale. Particolarmente interessante l'esame della ricezione artistica del primo conflitto mondiale che si manifestava da una lato nella celebrazione delle personalità eroiche che contribuirono alla vittoria dall'altro nell'interpretazione dei risvolti drammatici, collettivi e individuali, della guerra. L'indagine si concentra su un campione di dipinti, sculture e monumenti con particolare riferimento alla produzione di Mario Rutelli, Domen…
"Un personaggio di fiaba generoso e gentile". O'Tama Kiyohara e l'amicizia con Mario ed Elisa Oliveri
2017
Il testo ricostruisce - anche attraverso alcuni documenti inediti - il quadro dei rapporti fra il poeta ed editore Mario Oliveri (1900-1963), lo scultore Vincenzo Ragusa e sua moglie, la pittrice O'Tama Kiyohara, dal 1925 sino al ritorno di O'Tama in Giappone, nel settembre 1932.
Automated detection and classification of synoptic scale fronts from atmospheric data grids
2021
<p>Automatic determination of fronts from atmospheric data is an important task for weather prediction as well as for research of synoptic scale phenomena. We developed a deep neural network to detect and classify fronts from multi-level ERA5 reanalysis data. Model training and prediction is evaluated using two different regions covering Europe and North America with data from two weather services. Due to a label deformation step performed during training we are able to directly generate frontal lines with no further thinning during post processing. Our network compares well against the weather service labels with a Critical Success Index higher than 66.9% and a Object Detecti…
Pumps as turbines (PATs) in water distribution networks affected by intermittent service
2013
A hydraulic model was developed in order to evaluate the potential energy recovery from the use of centrifugal pumps as turbines (PATs) in a water distribution network characterized by the presence of private tanks. The model integrates the Global Gradient Algorithm (GGA), with a pressure-driven model that permits a more realistic representation of the influence on the network behaviour of the private tanks filling and emptying. The model was applied to a real case study: a District Metered Area in Palermo (Italy). Three different scenarios were analysed and compared with a baseline scenario (Scenario 0 – no PAT installed) to identify the system configuration with added PATs that permits th…
Full configuration interaction calculation of singlet excited states of Be3
2004
The full configuration interaction (FCI) study of the singlets vertical spectrum of the neutral beryllium trimer has been performed using atomic natural orbitals [3s2p1d] basis set. The FCI triangular equilibrium structure of the ground state has been used to calculate the FCI vertical excitation energies up to 4.8 eV. The FCI vertical ionization potential for the same geometry and basis set amounts to 7.6292 eV. The FCI dipole and quadrupole transition moments from the ground state are reported as well. The FCI electric quadrupole moment of the X (3)A(1) (') ground state has been also calculated with the same basis set (Theta(zz)=-2.6461 a.u., Theta(xx)=Theta(yy)=-1/2Theta(zz)). Twelve of …
A novel noise figure and gain test set for microwave devices
2002
A new instrument for the measurement of noise and gain of microwave devices is presented. It differs from the commercial ones in the accomplishment of the gain measurement and is also useful for measuring mismatched devices such as transistors, The instrument is driven via HP-IB by a PC and a user-friendly virtual panel is designed to perform all the required operations. Also included is the possibility of removing the second-stage noise contribution and correcting various sources of error (source ENR variations, temperature variations, etc.). The test set provides a very good accuracy for both matched and mismatched devices, usually limited by source ENR accuracy and step attenuator repeat…
Electron delocalization in mixed-valence Keggin polyoxometalates. Ab initio calculation of the local effective transfer integrals and its consequence…
2002
We present a quantitative evaluation of the influence of the electron transfer on the magnetic properties of mixed-valence polyoxometalates reduced by two electrons. For that purpose, we extract from valence-spectroscopy ab initio calculations on embedded fragments the value of the transfer integrals between W nearest-neighbor atoms in a mixed-valence alphaPW(12)O(40) polyoxowolframate Keggin anion. In contradiction with what is usually assumed, we show that the electron transfer between edge-sharing and corner-sharing WO(6) octahedra have very close values. Considering fragments of various ranges, we analyze the accuracy of calculations on fragments based on only two WO(5) pyramids which s…
Robots, labor markets, and universal basic income
2020
Automation is a big concern in modern societies in view of its widespread impact on many socioeconomic issues including income, jobs, and productivity. While previous studies have concentrated on determining the effects on jobs and salaries, our aim is to understand how automation affects productivity, and how some policies, such as taxes on robots or universal basic income, moderate or aggravate those effects. To this end, we have designed an experiment where workers make productive effort decisions, and managers can choose between workers and robots to do these tasks. In our baseline treatment, we measure the effort made by workers who may be replaced by robots, and also elicit firm repla…
On-board Energy Consumption Assessment for Symbolic Execution Models on Embedded Devices
2020
Internet of Things (IoT) applications operate in several domains while requiring seamless integration among heterogeneous objects. Regardless of the specific platform and context, IoT applications demand high energy efficiency. Adopting resource-constrained embedded devices for IoT applications means ensuring low power consumption, low maintenance costs and possibly longer battery life. Meeting these requirements is particularly arduous as programmers are not able to monitor the energy consumption of their own software during development or when applications are finally deployed. In this paper, we discuss on-board real-time energy evaluation of both hardware and software during the developm…