340 research outputs found
VOLSCAT2.0: The new version of the package for electron and positron scattering off molecular targets
No full textThis is a Author's Accepted Manuscritpt (post-peer reviewed) version of the following final paper:
Sanna, N, Morelli, G, Orlandini, S and Baccarelli, I "VOLSCAT2.0: The new version of the package for electron and positron scattering off molecular targets," COMPUTER PHYSICS COMMUNICATIONS (235), 2019, pp. 366-377
Methods for the accelerated computation of Green’s functions with 2-D periodicity in layered media
No full textA review of some recent methods for the efficient
computation of two-dimensional (2-D) periodic Green’s
functions in layered dielectric media is presented in this
contribution. 2-D periodic vector and scalar mixedpotential Green’s functions for a multilayered
environment are derived in the spectral domain first,
and then the corresponding spatial-domain quantities are
obtained through an efficient sum of spatial harmonics.
Numerical acceleration techniques are performed by
extracting slowly-converging and singular terms.
Kummer-Poisson’s formula and Ewald’s
transformations are applied when the sum of the
extracted terms is added back and a comparison is
performed, which shows the efficiency of the proposed
methods for this kind of problems
3-D Green’s function in 1-D periodic structures: a comparative analysis of acceleration techniques
No full textIn this work we treat in detail the acceleration of the freespace scalar Green’s function in three dimensional (3-D)
structures with one dimensional (1-D) periodicity. We
analyze the methods able to deal with a complex phase
shift, necessary to study complex waves in periodic structures. We present a spectral Kummer-Poisson’s decomposition; then we extend the application of the Ewald’s
method by performing an optimization of the relevant
splitting parameter, and we also find an integral representation. Comparisons among the various acceleration
methods are performed, thus providing fundamental information on their actual efficiency
Modal properties of surface and leaky waves propagating at arbitrary angles along a metal strip grating on a grounded slab
No full textIn this paper, a full-wave analysis is presented of the dispersion properties of modes supported by a grounded dielectric slab periodically loaded with metal strips, which represents a canonical configuration employed in planar microwave antennas and arrays and in the realization of artificially hard and soft surfaces. Propagation of surface and leaky modes at arbitrary angles is considered here, without any restrictive assumption on the values of the involved physical and geometrical parameters. Spectral properties of modes are studied, by deriving generalized conditions for establishing the proper or improper nature of the spatial harmonics in the Floquet representation of the fields. The proposed approach, based on a full-wave moment-method discretization of the relevant electric-field integral equation in the spectral domain, is validated through comparisons with the available data in the literature. Novel results are presented which illustrate the continuous evolution of modes as a function of the propagation angle along the grating, both in surface and leaky propagation regimes
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Computed vibrational excitation of CF_{4} by low-energy electrons and positrons: Comparing calculations and experiments
No full textQuantum calculations for the excitation of the asymmetric modes of the CF4 target gas, ν3 and ν4, by impact of low-energy electrons and positrons are carried out in the energy range around 1 eV and are compared with recent experimental findings. The similarities and differences between the two types of projectiles, and the two different modes, are analyzed and discussed vis à vis the present accord with the experimental results
Electron-Driven molecular processes induced in biological systems by electro magnetic and other ionizing sources.
No full textControl Of Molecular Processes Induced by Electrons and Photons: Experiments and Interpretations
No full textQoS Stochastic Traffic Engineering for the wireless support of real-time streaming applications
No full textIn this work, the Stochastic Traffic Engineering (STE) problem arising from the support of QoS-demanding real-time (e.g., delay and delay-jitter sensitive) media-streaming applications over unreliable IP-over-wireless pipes is addressed. Two main contributions are presented. First, we develop an optimal resource-management policy that allows a joint scheduling of the source rate, transmit energy and playout rate. Salient features of the proposed scheduling policy are that: (i) it is self-adaptive; and, (ii) it is able to provide hard (i.e., deterministic) QoS guarantees, in terms of hard limited playout delay, playout rate-jitter and pre-roll delay. Second, by referring to power and bandwidth limited access scenarios, we develop a traffic analysis of the underlying IP-over-wireless pipes that allows us to analyze the effects of both fading-induced errors and congestion-induced packet's losses on the end-to-end performance of the proposed scheduler. © 2011 Elsevier B.V. All rights reserved
Trasfo_mace. Ipotesi di trasformazione e riuso per l'ex Macello di Milano
No full textIl volume presenta gli esiti dell’attività progettuale del Laboratorio di Progettazione Architettonica e Urbana coordinato da Marco Lucchini e Marco Baccarelli, attivo presso il Corso di Laurea Magistrale (PSPA Interni) della Scuola AUIC del Politecnico di Milano che ha affrontato, nell’anno accademico 2017/18, il tema della riqualificazione dell’Ex Macello di Milano. Si tratta di progetti di trasformazione sviluppati dalla scala urbana a quella architettonica assumendo come tema il progetto della casa. Inoltre, sono presentate due tesi di Laurea Magistrale che, con approcci diversi, hanno affrontato anch’esse la riqualificazione dell’ex Macello.
L’attività di progettazione, sviluppata nel quadro della didattica, è stata l’occasione per una più ampia riflessione sui temi della progettazione urbana nelle aree dismesse, delle relazioni tra casa e città come strumento di trasformazione del tessuto urbano e del riuso, come alternativa alla demolizione delle preesistenze.
Ogni pratica progettuale, compresa quella didattica, ha necessità di un supporto teorico in base al quale il progetto esercita un ruolo critico. Di conseguenza la presentazione dei progetti è anticipata da alcuni saggi scritti da Marco Baccarelli, Isabella Inti, Beatrice Benatti, E. Zobbi, M. Zangrande finalizzati a porre quelle istanze che possono far nascere una dialettica tra pensiero e azione progettuale
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