Search results for "ESA"

Channel Assembling with Priority-Based Queues in Cognitive Radio Networks: Strategies and Performance Evaluation

2014

[EN] With the implementation of channel assembling (CA) techniques, higher data rate can be achieved for secondary users in multi-channel cognitive radio networks. Recent studies which are based on loss systems show that maximal capacity can be achieved using dynamic CA strategies. However the channel allocation schemes suffer from high blocking and forced termination when primary users become active. In this paper, we propose to introduce queues for secondary users so that those flows that would otherwise be blocked or forcibly terminated could be buffered and possibly served later. More specifically, in a multi-channel network with heterogeneous traffic, two queues are separately allocate…

NUOVI SISTEMI DI GESTIONE E STRATEGIE DI SVILUPPO PER IL PAESAGGIO CULTURALE DELL'AREA MEDITERRANEA

2022

Quantum interference and the time-dependent radiation of nanojunctions

2021

Using the recently developed time-dependent Landauer-B\"uttiker formalism and Jefimenko's retarded solutions to the Maxwell equations, we show how to compute the time-dependent electromagnetic field produced by the charge and current densities in nanojunctions out of equilibrium. We then apply this formalism to a benzene ring junction, and show that geometry-dependent quantum interference effects can be used to control the magnetic field in the vicinity of the molecule. Then, treating the molecular junction as a quantum emitter, we demonstrate clear signatures of the local molecular geometry in the non-local radiated power.

Reliability of numerical models for simulating galvanic corrosion processes

2012

International audience; Maturity of numerical simulation represents an important issue in the development of predictive models of galvanic corrosion. As widely used in electrochemical engineering, a coupled electrochemical-transport-reaction (CETR) model is recommended to simulate the current distribution above a galvanic corrosion cell made of the cut-edge of a galvanized steel sheet. Nevertheless, simulating current density distributions obtained experimentally by scanning vibrating electrode technique (SVET) above such a galvanic cell appears to be more accurate using an electrostatic model considering a homogeneous conductivity. In this case, the absence of concentration gradients next …

Electrochemical deposition of CZTS thin films on flexible substrate

2014

Abstract In this work, we report some preliminary results concerning the fabrication of quaternary semiconductor Cu2ZnSnS4 (CZTS) thin films on a flexible substrate through the simultaneous electrodeposition of elements having different standard electrochemical potentials. CZTS thin films were obtained by potentiostatic deposition from aqueous baths at room temperature and under N2 atmosphere, varying bath composition. Chemical composition and structure of the electrodeposited films were evaluated by EDS, SEM, RAMAN and XRD. Preliminary results on the photoelectrochemical behaviour of the films will be also presented.

Observations of molecular hydrogen (H2) mixing ratio and stable isotopic composition (deuterium content) at the Cabauw tall tower in the Netherlands

2016

This zip file contains the final corrected data that were used for the journal article "Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands" by Batenburg et al., Atmospheric Environment, 2016, doi:10.1016/j.atmosenv.2016.09.058   Please cite the original AtmosEnv article when using these data. The paper also contains more information about how these data were collected and calibrated, and on how the quality control flags were assigned. All samples were collected at the Cabauw tower, at the CESAR site (51.971° N, 4.927° E, http://www.cesar-observatory.nl/). H2 and deltaD(H2) are calibrated using one to four laboratory re…

Sorption properties of algae Spirogyra sp. and their use for determination of heavy metal ions concentrations in surface water.

2010

Abstract Kinetics of heavy-metal ions sorption by alga Spirogyra sp. was evaluated experimentally in the laboratory, using both the static and the dynamic approach. The metal ions – Mn2+, Cu2+, Zn2+ and Cd2+ – were sorbed from aqueous solutions of their salts. The static experiments showed that the sorption equilibria were attained in 30 min, with 90-95% of metal ions sorbed in first 10 min of each process. The sorption equilibria were approximated with the Langmuir isotherm model. The algae sorbed each heavy metal ions proportionally to the amount of this metal ions in solution. The experiments confirmed that after 30 min of exposition to contaminated water, the concentration of heavy meta…

Epimetrum ad oleum conditum (Rhein. Mus. 146, 426-429)

2008

Si chiarisce il senso di un passo di Svetonio, che ha il corrispondente in Plutarco. The meaning of a passage by Suetonius, which has its counterpart in Plutarch, is clarified.

Allearsi col nemico. Pompeo, alcuni pregiudizi etnografici, i destini della storia nell’ottavo libro della Pharsalia di Lucano

2022

Analisi del passo dell'ottavo libro della Pharsalia, in cui si delibera sulle decisioni da prendere in merito alle alleanze. Il discorso si rivela carico di alcuni pregiudizi etnografici Analysis of the passage from the eighth book of Pharsalia, in which it deliberates on the decisions to be taken regarding the alliances. The speech turns out to be laden with some ethnographic prejudices

Nullum... sine nomine saxum. Lucano e le 'rovine' della storia

2019

The paper analyzes the well-known episode of Caesar visiting the ruins of troy (Luc. 9,9 50-999), focusing in particular on the poet’s desecrating voice, a voice against the Virgilian interpretation of history. Through Caesar’s gestures, words and prayers, Lucan expresses a critical judgment of his actions and of those who, among his successors, first of all Augustus, had advanced the project of a glorious re-founding of Troy. A project destined to be blatantly denied by history.