A bacterial ratchet motor (2009)
Di Leonardo, R., Angelani, L., Ruocco, G., Iebba, V., Conte, M. P., Schippa, S., ...
Self-propelling bacteria are a dream of nano-technology. These unicellular organisms are not just capable of living and reproducing, but they can swim very efficiently, sense the environment and look...
Shear thickening in molecular liquids characterized by inverse melting (2009)
Angelini, R., Salvi, G., Ruocco, G.
We studied the rheological behavior of a molecular solution composed of $\alpha$-cyclodextrin, water and 4-methylpyridine, a liquid known to undergo inverse melting, at different temperatures and...
COMPUTER SIMULATION OF POLARIZABLE FLUIDS: A PARALLEL IMPLEMENTATION USING LINDA AND PVM (2009)
V. Di Martino, G. Ruocco, M. Sampoli
A parallel version of a molecular dynamic program has been implemented and tested on a cluster of alpha processors connected via gigaswitch. A replicated data method has been used to evaluate the...
Colloidal attraction induced by a temperature gradient (2008)
Di Leonardo, R., Ianni, F., Ruocco, G.
Colloidal crystals are of extreme importance for applied research, such as photonic crystals technology, and for fundamental studies in statistical mechanics. Long range attractive interactions, such...
Influence of an adsorbing polymer in the aging dynamics of Laponite clay suspensions (2008)
Zulian, L., Ruzicka, B., Ruocco, G.
Clay-polymer dispersions in aqueous solutions have attracted a great interest in recent years due to their industrial applications and intriguing physical properties. Aqueous solutions of bare...
DIRETTORE RESPONSABILE: (2008)
Consiglio Nazionale, Delle Ricerche, Cover Photo, C. Andreani, Comitato Di Direzione, ...
The high temperature proton conducting phase of CsDSO 4 [5]. The individual atom positions in a 5376 atom (8x8x3 unit cell) model have been translated into a single unit cell- S are green, O are red...
Phase diagram and complexity of mode-locked lasers: from order to disorder (2008)
Leuzzi, L., Conti, C., Folli, V., Angelani, L., Ruocco, G.
We investigate mode-locking processes in lasers displaying a variable degree of structural randomness, from standard optical cavities to multiple-scattering media. By employing methods mutuated from...
High frequency dynamics in liquid nickel: an IXS study (2008)
Cazzato, S., Scopigno, T., Hosokawa, S., Inui, M., Pilgrim, W-C., Ruocco, G.
Owing to their large relatively thermal conductivity, peculiar, non-hydrodynamic features are expected to characterize the acoustic-like excitations observed in liquid metals. We report here an...
Hydrodynamic Interactions in Two Dimensions (2008)
Di Leonardo, R., Keen, S., Ianni, F., Leach, J., Padgett, M., Ruocco, G.
We measure hydrodynamic interactions between colloidal particles confined in a thin sheet of fluid. The reduced dimensionality, compared to a bulk fluid, increases dramatically the range of...
Phase diagram of a solution undergoing inverse melting (2008)
Angelini, R., Ruocco, G., De Panfilis, S., Sette, F.
The phase diagram of $\alpha$-cyclodextrin/water/4-methylpyridine solutions, a system undergoing inverse melting, has been studied by differential scanning calorimetry, rheological methods, and...
Arrested state of clay-water suspensions: gel or glass? (2008)
Ruzicka, B., Zulian, L., Angelini, R., Sztucki, M., Moussaid, A., Ruocco, G.
The aging of a charged colloidal system has been studied by Small Angle X-rays Scattering, in the exchanged momentum range Q=0.03 - 5 nm-1, and by Dynamic Light Scattering, at different clay...
Computer Simulation Of Polarizable Fluids: A Parallel Implementation Using Linda And Pvm (2007)
V. Di Martino, G. Ruocco, M. Sampoli
A parallel version of a molecular dynamic program has been implemented and tested on a cluster of alpha processors connected via gigaswitch. A replicated data method has been used to evaluate the...
The very long range nature of capillary interactions in liquid films (2007)
Di Leonardo, R., Saglimbeni, F., Ruocco, G.
Micron-sized objects confined in thin liquid films interact through forces mediated by the deformed liquid-air interface. This capillary interactions provide a powerful driving mechanism for the...
Vibrational excitations in systems with correlated disorder (2007)
Schirmacher, W., Schmid, B., Tomaras, C., Viliani, G., Baldi, G., Ruocco, G., ...
We investigate a $d$-dimensional model ($d$ = 2,3) for sound waves in a disordered environment, in which the local fluctuations of the elastic modulus are spatially correlated with a certain...
Phase transitions and topology in 2+k XY mean-field models (2007)
The thermodynamics and topology of mean-field models with 2+k body interaction terms (generalizing XY model) are derived. Focusing on two particular cases (2+4 and 2+6 body interaction terms), a...
Light-matter interaction in Mie nanolasers (2007)
Conti, C., Fratalocchi, A., Ruocco, G.
By deriving a three dimensional vector set of Maxwell-Bloch equations, we report on an ab-initio investigation of a spherical Mie nanolaser. Parallel numerical simulations predict a rich physical...
Parametric resonance of optically trapped aerosols (2007)
Leonardo, R.Di., Ruocco, G., Leach, J., Padgett, M.J., Wright, A.*, Girkin, J.M.*, ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over- to underdamped oscillations. The spectrum of position fluctuations evolves from a...
Parametric resonance of optically trapped aerosols (2007)
Leonardo, R.Di., Ruocco, G., Leach, J., Padgett, M.J., Wright, A., Girkin, J.M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over- to underdamped oscillations. The spectrum of position fluctuations evolves from a...
Parametric resonance of optically trapped aerosols (2007)
Leonardo, R.Di., Ruocco, G., Leach, J., Padgett, M.J., Wright, A., Girkin, J.M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over- to underdamped oscillations. The spectrum of position fluctuations evolves from a...
Parametric resonance of optically trapped aerosols (2007)
Di Leonardo, R., Ruocco, G., Leach, J., Padgett, M.J., Wright, A.J., Girkin, J.M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over- to underdamped oscillations. The spectrum of position fluctuations evolves from a...
Shear banding phenomena in a Laponite suspension (2007)
Ianni, F., Di Leonardo, R., Gentilini, S., Ruocco, G.
Shear localization in an aqueous clay suspension of Laponite is investigated through dynamic light scattering, which provides access both to the dynamics of the system (homodyne mode) and to the...
Parametric Resonance of Optically Trapped Aerosols (2007)
Di Leonardo, R., Ruocco, G., Leach, J., Padgett, M. J., Wright, A. J., Girkin, J. M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a...
Acoustic attenuation in glasses and its relation with the boson peak (2007)
Schirmacher, W., Ruocco, G., Scopigno, T.
A theory for the vibrational dynamics in disordered solids [W. Schirmacher, Europhys. Lett. {\bf 73}, 892 (2006)], based on the random spatial variation of the shear modulus, has been applied to...
Mode-locking transitions in nano-structured weakly disordered lasers (2006)
Angelani, L., Conti, C., Prignano, L., Ruocco, G., Zamponi, F.
We report on a statistical approach to mode-locking transitions of nano-structured laser cavities characterized by an enhanced density of states. We show that the equations for the interacting modes...
Dynamics and geometric properties of the k-Trigonometric model (2006)
Zamponi, F., Angelani, L., Cugliandolo, L. F., Kurchan, J., Ruocco, G.
We analyze the dynamics and the geometric properties of the Potential Energy Surfaces (PES) of the k-Trigonometric Model (kTM), defined by a fully-connected k-body interaction. This model has no...
Ianni, F., Di Leonardo, R., Gentilini, S., Ruocco, G.
The aging dynamics after shear rejuvenation in a glassy, charged clay suspension have been investigated through dynamic light scattering (DLS). Two different aging regimes are observed: one is...
High Frequency dynamics in metallic glasses (2006)
Scopigno, T., Angelini, R., Albergamo, F., Ruocco, G.
Using Inelastic X-ray Scattering we studied the collective dynamics of the glassy alloy Ni$_{33}$Zr$_{67}$ in the first pseudo Brillouin zone, an energy-momentum region still unexplored in metallic...
On the analysis of the vibrational Boson peak and low-energy excitations in glasses (2006)
Yannopoulos, S. N., Andrikopoulos, K. S., Ruocco, G.
Implications of reduction procedures applied to the low energy part of the vibrational density of states in glasses and supercooled liquids are considered by advancing a detailed comparison between...
Adiabatic and isothermal sound waves: the case of supercritical nitrogen (2005)
Bencivenga, F., Cunsolo, A., Krisch, M., Monaco, G., Ruocco, G., Sette, F.
The acoustic sound dispersion of nitrogen in its liquid and supercritical phases has been studied by Inelastic X-Ray Scattering. Approaching supercritical conditions, the gradual disappearance of the...
Glassy behavior of light (2005)
Angelani, L., Conti, C., Ruocco, G., Zamponi, F.
We study the nonlinear dynamics of a multi-mode random laser using the methods of statistical physics of disordered systems. A replica-symmetry breaking phase transition is predicted as a function of...
More on phase diagram of Laponite (2005)
Ruzicka, B., Zulian, L., Ruocco, G.
The phase diagram of a charged colloidal system (Laponite) has been investigated by dynamic light scattering in a previously unexplored range of salt and clay concentrations. Specifically the clay...
Angelani, L., Ruocco, G., Zamponi, F.
We address the question of the quantitative relationship between thermodynamic phase transitions and topological changes in the potential energy manifold analyzing two classes of one dimensional...
Hard sphere-like dynamics in a non hard sphere liquid (2005)
Scopigno, T., Di Leonardo, R., Comez, L., Baron, A. Q. R., Fioretto, D., Ruocco, G.
The collective dynamics of liquid Gallium close to the melting point has been studied using Inelastic X-ray Scattering to probe lengthscales smaller than the size of the first coordination shell....
High frequency longitudinal and transverse dynamics in water (2005)
Pontecorvo, E., Krisch, M., Cunsolo, A., Monaco, G., Mermet, A., Verbeni, R., ...
High-resolution, inelastic x-ray scattering measurements of the dynamic structure factor S(Q,\omega) of liquid water have been performed for wave vectors Q between 4 and 30 nm^-1 in distinctly...
Relaxation dynamics in H(x) H2O(1−x) solutions. (2005)
Angelini, R., Giura, P., Monaco, G., Ruocco, G., Sette, F.
The high-frequency dynamics of HFxH2O1−x solutions has been investigated by inelastic x-ray scattering. The measurements have been performed as a function of the concentration in the range...
Angelini, R., Giura, P., Henriquet, C., Monaco, G., Verbeni, R., Ruocco, G., ...
In order to study the dynamic structure factor of hydrogen fluoride and its water solutions, we have realized a sample container able to resist these highly reacting hydrogen-bonded liquids and...
Saddles and softness in simple model liquids (2004)
Angelani, L., De Michele, C., Ruocco, G., Sciortino, F.
We report a numerical study of saddles properties of the potential energy landscape for soft spheres with different softness, i.e. different power n of the interparticle repulsive potential. We find...
Aging under Shear: Structural Relaxation of a Non-Newtonian Fluid (2004)
Di Leonardo, R., Ianni, F., Ruocco, G.
The influence of an applied shear field on the dynamics of an aging colloidal suspension has been investigated by the dynamic light scattering determination of the density autocorrelation function....
Topological properties of the mean field phi^4 model (2004)
Andronico, A., Angelani, L., Ruocco, G., Zamponi, F.
We study the thermodynamics and the properties of the stationary points (saddles and minima) of the potential energy for a phi^4 mean field model. We compare the critical energy Vc (i.e. the...
Generalized fluctuation relation and effective temperatures in a driven fluid (2004)
Zamponi, F., Ruocco, G., Angelani, L.
By numerical simulation of a Lennard-Jones like liquid driven by a velocity gradient \gamma we test the fluctuation relation (FR) below the (numerical) glass transition temperature T_g. We show that,...
Microscopic dynamics and relaxation processes in liquid Hydrogen Fluoride (2004)
Angelini, R., Giura, P., Fioretto, D., Monaco, G., Ruocco, G., Sette, F.
Inelastic x-ray scattering and Brillouin light scattering measurements of the dynamic structure factor of liquid hydrogen fluoride have been performed in the temperature range$ T=214\div 283 K$. The...
Routes to gelation in a clay suspension (2004)
Ruzicka, B., Zulian, L., Ruocco, G.
The gelation of water suspension of a synthetic clay (Laponite) has been studied by dynamic light scattering in a wide range of clay weight concentration (Cw = 0.003-0.031). At variance with previous...
Evidence of anomalous dispersion of the generalized sound velocity in glasses (2004)
Ruzicka, B., Scopigno, T., Caponi, S., Fontana, A., Pilla, O., Giura, P., ...
The dynamic structure factor, S(Q,w), of vitreous silica, has been measured by inelastic X-ray scattering in the exchanged wavevector (Q) region Q=4-16.5 nm-1 and up to energies hw=115 meV in the...
Landscapes and Fragilities (2004)
Ruocco, G., Sciortino, F., Zamponi, F., De Michele, C., Scopigno, T.
The concept of fragility provides a possibility to rank different supercooled liquids on the basis of the temperature dependence of dynamic and/or thermodynamic quantities. We recall here the...
Fragility in p-spin models (2004)
Parisi, G., Ruocco, G., Zamponi, F.
We investigate the relation between fragility and phase space properties - such as the distribution of states - in the mean field p-spin model, a solvable model that has been frequently used in...
Collective dynamics in molten potassium: an Inelastic X-ray Scattering study (2004)
Monaco, A., Scopigno, T., Benassi, P., Giugni, A., Monaco, G., Nardone, M., ...
The high frequency collective dynamics of molten potassium has been investigated by inelastic x-ray scattering, disclosing an energy/momentum transfer region unreachable by previous neutron...
High frequency dynamics in a monatomic glass (2003)
Scopigno, T., Di Leonardo, R., Ruocco, G., Baron, A. Q. R., Tsutsui, S., Bossard, F., ...
The high frequency dynamics of glassy Selenium has been studied by Inelastic X-ray Scattering at beamline BL35XU (SPring-8). The high quality of the data allows one to pinpoint the existence of a...
Fluctuations of entropy production in the isokinetic ensemble (2003)
Zamponi, F., Ruocco, G., Angelani, L.
We discuss the microscopic definition of entropy production rate in a model of a dissipative system: a sheared fluid in which the kinetic energy is kept constant via a Gaussian thermostat. The total...
A spectroscopic cell for fast pressure jumps across the glass transition line (2003)
Di Leonardo, R., Scopigno, T., Ruocco, G., Buontempo, U.
We present a new experimental protocol for the spectroscopic study of the dynamics of glasses in the aging regime induced by sudden pressure jumps (crunches) across the glass transition line. The...
General features of the energy landscape in Lennard-Jones like model liquids (2003)
Angelani, L., Ruocco, G., Sampoli, M., Sciortino, F.
Features of the energy landscape sampled by supercooled liquids are numerically analyzed for several Lennard-Jones like model systems. The properties of quasisaddles (minima of the square gradient of...
Dynamics and geometric properties of the k-Trigonometric model (2003)
Zamponi, F., Angelani, L., Cugliandolo, L. F., Kurchan, J., Ruocco, G.
We analyze the dynamics and the geometric properties of the Potential Energy Surfaces (PES) of the k-Trigonometric Model (kTM), defined by a fully-connected k-body interaction. This model has no...
Potential Energy Landscape in Lennard-Jones binary mixture model (2003)
Sampoli, M., Benassi, P., Eramo, R., Angelani, L., Ruocco, G.
The potential energy landscape in the Kob-Andersen Lennard-Jones binary mixture model has been studied carefully from liquid down to the supercooled regime, from T =2 down to T =0.46. One thousand of...
Dynamics and geometric properties of the k-Trigonometric model (2003)
Zamponi, F., Angelani, L., Cugliandolo, L. F., Kurchan, J., Ruocco, G.
We analyze the dynamics and the geometric properties of the Potential Energy Surfaces (PES) of the k-Trigonometric Model (kTM), defined by a fully-connected k-body interaction. This model has no...
Dynamics and geometric properties of the k-Trigonometric model (2003)
Zamponi, F., Angelani, L., Cugliandolo, L. F., Kurchan, J., Ruocco, G.
We analyze the dynamics and the geometric properties of the Potential Energy Surfaces (PES) of the k-Trigonometric Model (kTM), defined by a fully-connected k-body interaction. This model has no...
Saddles and dynamics in a solvable mean-field model (2002)
Angelani, L., Ruocco, G., Zamponi, F.
We use the saddle-approach, recently introduced in the numerical investigation of simple model liquids, in the analysis of a mean-field solvable system. The investigated system is the k-trigonometric...
Di Leonardo, R., Taschin, A., Sampoli, M., Torre, R., Ruocco, G.
The density response of supercooled glycerol to an impulsive stimulated thermal grating (q=0.63 micron^-1) has been studied in the temperature range (T=200-340 K) where the structure rearrangement...
Transverse acoustic nature of the excess of vibrational states in vitreous silica (2002)
Pilla, O., Caponi, S., Fontana, A., Montagna, M., Rossi, F., Viliani, G., ...
We present a numerical simulation study of the density-dependence (rho = 2.2 - 4.0 g/cm^3) of the high-energy collective dynamics in vitreous silica at mesoscopic wavevectors (Q = 1 - 18 nm^-1). The...
High frequency acoustic modes in liquid gallium at the melting point (2002)
Scopigno, T., Filipponi, A., Krisch, M., Monaco, G., Ruocco, G., Sette, F.
The microscopic dynamics in liquid gallium (l-Ga) at melting (T=315 K) has been studied by inelastic x-ray scattering. We demonstrate the existence of collective acoustic-like modes up to...
Evidence of short time dynamical correlations in simple liquids (2002)
Scopigno, T., Ruocco, G., Sette, F., Viliani, G.
We report a molecular dynamics (MD) study of the collective dynamics of a simple monatomic liquid -interacting through a two body potential that mimics that of lithium- across the liquid-glass...
Scopigno, T., Yannopoulos, S. N., Kastrissios, D. Th., Monaco, G., Pontecorvo, E., Ruocco, G., ...
Inelastic X-ray Scattering measurements of the dynamics structure factor have bene performed on vitreous Beryllium Fluoride ({\it v-}BeF$_2$) at $T$=297 K in the momentum transfer, $Q$, range...
Experimental evidence for high frequency transverse-like excitations in glasses (2002)
Scopigno, T., Pontecorvo, E., Di Leonardo, R., Krisch, M., Monaco, G., Ruocco, G., ...
The dynamic structure factor of glassy and liquid glycerol has been measured by inelastic X-ray scattering in the exchanged momentum ($Q$) region $Q$=2$\div$23 nm$^{-1}$ and in the temperature range...
Topological Signature of First Order Phase Transitions (2002)
Angelani, L., Casetti, L., Pettini, M., Ruocco, G., Zamponi, F.
We show that the presence and the location of first order phase transitions in a thermodynamic system can be deduced by the study of the topology of the potential energy function, V(q), without...
Crossover between Equilibrium and Shear-controlled Dynamics in Sheared Liquids (2002)
Angelani, L., Ruocco, G., Sciortino, F., Tartaglia, P., Zamponi, F.
We present a numerical simulation study of a simple monatomic Lennard-Jones liquid under shear flow, as a function of both temperature and shear rate. By investigating different observables we find...
Angelani, L., Di Leonardo, R., Ruocco, G., Scala, A., Sciortino, F.
The supercooled dynamics of a Lennard-Jones model liquid is numerically investigated studying relevant points of the potential energy surface, i.e. the minima of the square gradient of total...
Mossa, S., Ruocco, G., Sampoli, M.
The depolarized light scattering spectra of the glass forming liquid ortho-terphenyl have been calculated in the low frequency region using molecular dynamics simulation. Realistic system's...
Inelastic X-ray scattering study of the collective dynamics in liquid sodium (2002)
Scopigno, T., Balucani, U., Ruocco, G., Sette, F.
Inelastic X-ray scattering data have been collected for liquid sodium at T=390 K, i.e. slightly above the melting point. Owing to the very high instrumental resolution, pushed up to 1.5 meV, it has...
Linac coherent light source (LCLS) conceptual design report (2002)
Arthur, J, Anfinrud, P, Audebert, P, Bane, K, Ben-Zvi, I, Bharadwaj, V, ...
Off-equilibrium dynamics in the energy landscape of a simple model glass (2001)
Di Leonardo, R., Angelani, L., Parisi, G., Ruocco, G., Scala, A., Sciortino, F.
The aging dynamics of a simple model glass is numerically investigated observing how it takes place in the potential energy landscape $V$. Partitioning the landscape in basins of minima of $|\nabla...
A stroll in the energy landscape (2001)
Scala, A., Angelani, L., Di Leonardo, R., Ruocco, G., Sciortino, F.
We review recent results on the potential energy landscape (PES) of model liquids. The role of saddle-points in the PES in connecting dynamics to statics is investigated, confirming that a change...
Vibrational origin of the fast relaxation processes in molecular glass-formers (2001)
Mossa, S., Monaco, G., Ruocco, G.
We study the interaction of the relaxation processes with the density fluctuations by molecular dynamics simulation of a flexible molecule model for o-terphenyl (oTP) in the liquid and supercooled...
Mossa, S., Monaco, G., Ruocco, G., Sampoli, M., Sette, F.
Using a realistic flexible molecule model of the fragile glass former orthoterphenyl, we calculate via molecular dynamics simulation the collective dynamic structure factor, recently measured in this...
Mossa, S., Ruocco, G., Sampoli, M.
We present a molecular dynamics study of the collective dynamics of a flexible model for the fragile glass-former orthoterphenyl [ S. Mossa, R. Di leonardo, G. Ruocco, and M. Sampoli, Phys. Rev. E...
Topological Description of the Aging Dynamics in Simple Glasses (2000)
Angelani, L., Di Leonardo, R., Parisi, G., Ruocco, G.
We numerically investigate the aging dynamics of a monatomic Lennard-Jones glass, focusing on the topology of the potential energy landscape which, to this aim, has been partitioned in basins of...
Evidence of two viscous relaxation processes in the collective dynamics of liquid lithium (2000)
Scopigno, T., Balucani, U., Ruocco, G., Sette, F.
New inelastic X-ray scattering experiments have been performed on liquid lithium in a wide wavevector range. With respect to the previous measurements, the instrumental resolution, improved up to 1.5...
Monaco, G., Caponi, S., Di Leonardo, R., Fioretto, D., Ruocco, G.
The Brillouin light scattering spectra of the o-terphenyl single crystal are compared with those of the liquid and the glass phases. This shows: i) the direct evidence of a fast relaxation at 5 GHz...
Collective dynamics of liquid aluminum probed by Inelastic X-ray Scattering (2000)
Scopigno, T., Balucani, U., Ruocco, G., Sette, F.
An inelastic X-ray scattering experiment has been performed in liquid aluminum with the purpose of studying the collective excitations at wavevectors below the first sharp diffraction peak. The high...
Saddles in the energy landscape probed by supercooled liquids (2000)
Angelani, L., Di Leonardo, R., Ruocco, G., Scala, A., Sciortino, F.
We numerically investigate the supercooled dynamics of two simple model liquids exploiting the partition of the multi-dimension configuration space in basins of attraction of the stationary points...
Pilla, O., Cunsolo, A., Fontana, A., Masciovecchio, C., Monaco, G., Montagna, M., ...
The dynamical structure factor (S(Q,E)) of vitreous silica has been measured by Inelastic X-ray Scattering varying the exchanged wavevector (Q) at fixed exchanged energy (E) - an experimental...
Frustration and sound attenuation in structural glasses (2000)
Angelani, L., Montagna, M., Ruocco, G., Viliani, G.
Three classes of harmonic disorder systems (Lennard-Jones like glasses, percolators above threshold, and spring disordered lattices) have been numerically investigated in order to clarify the effect...
Off-Equilibrium Effective Temperature in Monatomic Lennard-Jones Glass (2000)
Di Leonardo, R., Angelani, L., Parisi, G., Ruocco, G.
The off-equilibrium dynamics of a monatomic Lennard-Jones glass is investigated after sudden isothermal density jumps (crunch) from well equilibrated liquid configurations towards the glassy state....
Density Fluctuations in Molten Lithium: Inelastic X-Ray Scattering Study (2000)
Scopigno, T., Balucani, U., Ruocco, G., Sette, F.
New inelastic X-ray scattering experiments have been performed in liquid lithium at two different temperatures: T=475 K (slightly above the melting point) and 600 K. Taking advantage of the absence...
Relaxation processes in harmonic glasses? (2000)
Ruocco, G., Sette, F., Di Leonardo, R., Monaco, G., Sampoli, M., Scopigno, T., ...
A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process...
Mossa, S., Di Leonardo, R., Ruocco, G., Sampoli, M.
We present a realistic model of the fragile glass former orthoterphenyl and the results of extensive molecular dynamics simulations in which we investigated its basic static and dynamic properties....
Fontana, A., Dell'Anna, R., Montagna, M., Rossi, F., Viliani, G., Ruocco, G., ...
New Raman and incoherent neutron scattering data at various temperatures and molecular dynamic simulations in amorphous silica, are compared to obtain the Raman coupling coefficient $C(\omega)$ and,...
Non-dynamic origin of the acoustic attenuation at high frequency in glasses (1999)
Ruocco, G., Sette, F., Di Leonardo, R., Fioretto, D., Lorenzen, M., Krisch, M., ...
The sound attenuation in the THz region is studied down to T=16 K in glassy glycerol by inelastic x-ray scattering. At striking variance with the decrease found below 100 K in the GHz data, the...
Phonon-like and single particle dynamics in liquid lithium (1999)
Scopigno, T., Balucani, U., Cunsolo, A., Masciovecchio, C., Ruocco, G., Sette, F., ...
The dynamic structure factor, S(Q,E), of liquid lithium (T=475 K) has been determined by inelastic x-ray scattering (IXS) in the momentum transfer region (Q = 1.4-110 nm-1). These data allow to...
Acoustic Nature of the Boson Peak in Vitreous Silica (1999)
Masciovecchio, C., Mazzacurati, V., Monaco, G., Ruocco, G., Scopigno, T., Sette, F., ...
New temperature dependent inelastic x-ray (IXS) and Raman (RS) scattering data are compared to each other and with existing inelastic neutron scattering data in vitreous silica (v-SiO_2), in the 300...
Potential Energy Landscape and Long Time Dynamics in a Simple Model Glass (1999)
Angelani, L., Parisi, G., Ruocco, G., Viliani, G.
We analyze the properties of a Lennard-Jones system at the level of the potential energy landscape. After an exhaustive investigation of the topological features of the landscape of the systems,...
Montagna, M., Ruocco, G., Viliani, G., Di Leonardo, R., Dusi, R., Monaco, G., ...
We propose an explanation for the quadratic dependence on the momentum $Q$, of the broadening of the acoustic excitation peak recently found in the study of the dynamic structure factor of many real...
Potential energy topology and relaxation processes in a model glass (1998)
Demichelis, F., Viliani, G., Ruocco, G.
We use computer simulation to investigate the topology of the potential energy $V(\{{\bf R}\})$ and to search for doublewell potential's (DWP) in a model glass . By a sequence of Newtonian and...
Energy landscape, two-level systems and entropy barriers in Lennard-Jones clusters (1998)
Daldoss, G., Pilla, O., Viliani, G., Ruocco, G.
We develop an efficient numerical algorithm for the identification of a large number of saddle points of the potential energy function of Lennard- Jones clusters. Knowledge of the saddle points...
High frequency sound waves in vitreous silica (1998)
Dell'Anna, R., Ruocco, G., Sampoli, M., Viliani, G.
We report a molecular dynamics simulation study of the sound waves in vitreous silica in the mesoscopic exchanged momentum range. The calculated dynamical structure factors are in quantitative...
Low-frequency Raman scattering in model disordered solids: percolators above threshold (1997)
Pilla, O., Viliani, G., DellAnna, R., Ruocco, G.
The Raman coupling coefficients of site- and bond-percolators at concentration higher than percolation threshold are computed for two scattering mechanisms: Bond Polarizability (BPOL) and...
ORIGIN OF LIGHT SCATTERING FROM DISORDERED SYSTEMS (1995)
Benassi, P., Frizzera, W., Montagna, M., Viliani, G., Mazzacurati, V., Ruocco, G., ...
Anelastic light scattering is computed numerically for model disordered systems (linear chains and 2-dimensional site and bond percolators), with and without electrical disorder. A detailed analysis...
Absence of Definite Scaling Laws in Raman Scattering from Fractals (1992)
Benassi, P., Pilla, O., Viliani, G., Ruocco, G., Signorelli, G., Mazzacurati, V., ...
The frequency dependence of the Raman coupling coefficient $C(\omega)$ is calculated numerically for square and cubic percolation clusters. No general scaling law in terms of the macroscopic...
A THEORETICAL MODEL FOR THE CONTINUOUS ORDER-DISORDER TRANSITION AT 703 K IN SUPERIONIC α-AgI (1981)
Mazzacurati, V., Ruocco, G., Signorelli, G., Cazzanelli, E., Fontana, A., Mariotto, G.
We interpret the Raman intensity behaviour and the depolarization ratio in superionic α-AgI on the basis of a theoretical model.
A THEORETICAL MODEL FOR THE CONTINUOUS ORDER-DISORDER TRANSITION AT 703 K IN SUPERIONIC α-AgI (1981)
Mazzacurati, V., Ruocco, G., Signorelli, G., Cazzanelli, E., Fontana, A., Mariotto, G.
We interpret the Raman intensity behaviour and the depolarization ratio in superionic α-AgI on the basis of a theoretical model.
A THEORETICAL MODEL FOR THE CONTINUOUS ORDER-DISORDER TRANSITION AT 703 K IN SUPERIONIC α-AgI (1981)
Mazzacurati, V., Ruocco, G., Signorelli, G., Cazzanelli, E., Fontana, A., Mariotto, G.
We interpret the Raman intensity behaviour and the depolarization ratio in superionic α-AgI on the basis of a theoretical model.
Peripheral blood mononuclear cells and regulatory T cells in acute viral hepatitis.
Barnaba, V, Tamburrini, E, Laghi, V, Cauda, R, Levrero, M, Ruocco, G, ...
During acute viral hepatitis, we observed a significant decrease in OKT4/OKT8 ratio with a significant increase in the OKT8 positive subset in acute type B and non-A-non-B hepatitis. This altered...
Barnaba, V, Musca, A, Cordova, C, Levrero, M, Ruocco, G, Albertini-Petroni, V, ...
The relationship between T cell subset, as defined by monoclonal antibodies, and suppressor cell function, using a short lived suppressor cell assay, was studied in 38 chronic hepatitis B virus (HBV)...