Long-range and short-range dihadron angular correlations in central PbPb collisions at psNN = 2:76 TeV

First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV over a broad range in relative pseudorapidity (Δν) and the full range of relative azimuthal angle (Δø). The data were collected with the CMS detector, at the LHC. A broadening of the away-side (Δø y≈ π) azimuthal correlation is observed at all Δν, as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in Δν are observed for particles with similar ø values. This phenomenon, also known as the \ridge, persists up to at least jΔνj = 4. For particles with transverse momenta (pT) of 2-4 GeV/c, the ridge is found to be most prominent when these particles are correlated with particles of pT = 2-6 GeV/c, and to be much reduced when paired with particles of pT = 10-12 GeV/c. Copyright CERN.

Proyecciones de población a largo plazo = Long-range population projections

Incluye Bibliografía

Planificación del desarrollo a largo plazo: notas sobre su esencia y metodología = Long-range development planning: notes on essence and methodology

Analiza las funciones de la planificacion, su relacion con el mercado y la economia a largo plazo, especialmente en lo que se refiere a la metodologia.

Observation of long-range, near-side angular correlations in pPb collisions at the LHC

Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, η, and full azimuth, φ, as a function of charged particle multiplicity and particle transverse momentum, pT. In high-multiplicity events, a long-range (2<|δη|<4), near-side (δφ≈0) structure emerges in the two-particle δη-δφ correlation functions. This is the first observation of such correlations in proton-nucleus collisions, resembling the ridge-like correlations seen in high-multiplicity pp collisions at s=7 TeV and in AA collisions over a broad range of center-of-mass energies. The correlation strength exhibits a pronounced maximum in the range of pT=1-1.5 GeV/c and an approximately linear increase with charged particle multiplicity for high-multiplicity events. These observations are qualitatively similar to those in pp collisions when selecting the same observed particle multiplicity, while the overall strength of the correlations is significantly larger in pPb collisions. © 2012 CERN.

Long-range development planning: notes on its substance and methodology

Revisa varios de los problemas que presenta la planificación del desarrollo a largo plazo: los aspectos políticos; la relación entre la planificación y el mercado en las economías mixtas; y los aspectos éticos y metodológicos.

Influence of a co-substituted A-site on structural characteristics and ferroelectricity of (Pb, Ba, Ca)TiO3 complex perovskites: analysis of local-, medium- and long-range order

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Long-range and short-range structures of cube-like shape SrTiO3 powders: microwave-assisted hydrothermal synthesis and photocatalytic activity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fingerprints of short-range and long-range structure in BaZr1-xHfxO3 solid solutions: an experimental and theoretical study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Unmanned platform for long-range remote analysis of volatile compounds in air samples

This paper describes a long-range remotely controlled CE system built on an all-terrain vehicle. A four-stroke engine and a set of 12-V batteries were used to provide power to a series of subsystems that include drivers, communication, computers, and a capillary electrophoresis module. This dedicated instrument allows air sampling using a polypropylene porous tube, coupled to a flow system that transports the sample to the inlet of a fused-silica capillary. A hybrid approach was used for the construction of the analytical subsystem combining a conventional fused-silica capillary (used for separation) and a laser machined microfluidic block, made of PMMA. A solid-state cooling approach was also integrated in the CE module to enable controlling the temperature and therefore increasing the useful range of the robot. Although ultimately intended for detection of chemical warfare agents, the proposed system was used to analyze a series of volatile organic acids. As such, the system allowed the separation and detection of formic, acetic, and propionic acids with signal-to-noise ratios of 414, 150, and 115, respectively, after sampling by only 30 s and performing an electrokinetic injection during 2.0 s at 1.0 kV.

Non-mean-field effects in systems with long-range forces in competition

We investigate the canonical equilibrium of systems with long-range forces in competition. These forces create a modulation in the interaction potential and modulated phases appear at the system scale. The structure of these phases differentiate this system from monotonic potentials, where only the mean-field and disordered phases exist. With increasing temperature, the system switches from one ordered phase to another through a first-order phase transition. Both mean-field and modulated phases may be stable, even at zero temperature, and the long-range nature of the interaction will lead to metastability characterized by extremely long time scales.

Entanglement entropy in long-range harmonic oscillators

We study the Von Neumann and Renyi entanglement entropy of long-range harmonic oscillators (LRHO) by both theoretical and numerical means. We show that the entanglement entropy in massless harmonic oscillators increases logarithmically with the sub-system size as S - c(eff)/3 log l. Although the entanglement entropy of LRHO's shares some similarities with the entanglement entropy at conformal critical points we show that the Renyi entanglement entropy presents some deviations from the expected conformal behaviour. In the massive case we demonstrate that the behaviour of the entanglement entropy with respect to the correlation length is also logarithmic as the short-range case. Copyright (c) EPLA, 2012

Non-Markovian stochastic processes and their applications: from anomalous diffusion to time series analysis

This work provides a forward step in the study and comprehension of the relationships between stochastic processes and a certain class of integral-partial differential equation, which can be used in order to model anomalous diffusion and transport in statistical physics. In the first part, we brought the reader through the fundamental notions of probability and stochastic processes, stochastic integration and stochastic differential equations as well. In particular, within the study of H-sssi processes, we focused on fractional Brownian motion (fBm) and its discrete-time increment process, the fractional Gaussian noise (fGn), which provide examples of non-Markovian Gaussian processes. The fGn, together with stationary FARIMA processes, is widely used in the modeling and estimation of long-memory, or long-range dependence (LRD). Time series manifesting long-range dependence, are often observed in nature especially in physics, meteorology, climatology, but also in hydrology, geophysics, economy and many others. We deepely studied LRD, giving many real data examples, providing statistical analysis and introducing parametric methods of estimation. Then, we introduced the theory of fractional integrals and derivatives, which indeed turns out to be very appropriate for studying and modeling systems with long-memory properties. After having introduced the basics concepts, we provided many examples and applications. For instance, we investigated the relaxation equation with distributed order time-fractional derivatives, which describes models characterized by a strong memory component and can be used to model relaxation in complex systems, which deviates from the classical exponential Debye pattern. Then, we focused in the study of generalizations of the standard diffusion equation, by passing through the preliminary study of the fractional forward drift equation. Such generalizations have been obtained by using fractional integrals and derivatives of distributed orders. In order to find a connection between the anomalous diffusion described by these equations and the long-range dependence, we introduced and studied the generalized grey Brownian motion (ggBm), which is actually a parametric class of H-sssi processes, which have indeed marginal probability density function evolving in time according to a partial integro-differential equation of fractional type. The ggBm is of course Non-Markovian. All around the work, we have remarked many times that, starting from a master equation of a probability density function f(x,t), it is always possible to define an equivalence class of stochastic processes with the same marginal density function f(x,t). All these processes provide suitable stochastic models for the starting equation. Studying the ggBm, we just focused on a subclass made up of processes with stationary increments. The ggBm has been defined canonically in the so called grey noise space. However, we have been able to provide a characterization notwithstanding the underline probability space. We also pointed out that that the generalized grey Brownian motion is a direct generalization of a Gaussian process and in particular it generalizes Brownain motion and fractional Brownain motion as well. Finally, we introduced and analyzed a more general class of diffusion type equations related to certain non-Markovian stochastic processes. We started from the forward drift equation, which have been made non-local in time by the introduction of a suitable chosen memory kernel K(t). The resulting non-Markovian equation has been interpreted in a natural way as the evolution equation of the marginal density function of a random time process l(t). We then consider the subordinated process Y(t)=X(l(t)) where X(t) is a Markovian diffusion. The corresponding time-evolution of the marginal density function of Y(t) is governed by a non-Markovian Fokker-Planck equation which involves the same memory kernel K(t). We developed several applications and derived the exact solutions. Moreover, we considered different stochastic models for the given equations, providing path simulations.

Control of the long-range self-organization of polycyclic aromatic hydrocarbons for device applications

Electronic devices based on organic semiconductors have gained increased attention in nanotechnology, especially applicable to the field of field-effect transistors and photovoltaic. A promising class of materials in this reseach field are polycyclic aromatic hydrocarbons (PAHs). Alkyl substitution of these graphenes results in the selforganization into one-dimensional columnar superstructures and provides solubility and processibility. The nano-phase separation between the π-stacking aromatic cores and the disordered peripheral alkyl chains leads to the formation of thermotropic mesophases. Hexa-peri-hexabenzocoronenes (HBC), as an example for a PAH, exhibits some of the highest values for the charge carrier mobility for mesogens, which makes them promising candidates for electronic devices. Prerequisites for efficient charge carrier transport between electrodes are a high purity of the material to reduce possible trapping sites for charge carriers and a pronounced and defect-free, long-range order. Appropriate processing techniques are required to induce a high degree of aligned structures in the discotic material over macroscopic dimensions. Highly-ordered supramolecular structures of different discotics, in particular, of HBC derivatives have been obtained by solution processing using the zone-casting technique, zone-melting or simple extrusion. Simplicity and fabrication of highly oriented columnar structures over long-range are the most essential advantages of these zone-processing methods. A close relation between the molecular design, self-aggregation and the processing conditions has been revealed. The long-range order achieved by the zone-casting proved to be suitable for field effect transistors (FET).

Correlations and Quantum Dynamics of 1D Fermionic Models: New Results for the Kitaev Chain with Long-Range Pairing

In the first part of the thesis, we propose an exactly-solvable one-dimensional model for fermions with long-range p-wave pairing decaying with distance as a power law. We studied the phase diagram by analyzing the critical lines, the decay of correlation functions and the scaling of the von Neumann entropy with the system size. We found two gapped regimes, where correlation functions decay (i) exponentially at short range and algebraically at long range, (ii) purely algebraically. In the latter the entanglement entropy is found to diverge logarithmically. Most interestingly, along the critical lines, long-range pairing breaks also the conformal symmetry. This can be detected via the dynamics of entanglement following a quench. In the second part of the thesis we studied the evolution in time of the entanglement entropy for the Ising model in a transverse field varying linearly in time with different velocities. We found different regimes: an adiabatic one (small velocities) when the system evolves according the instantaneous ground state; a sudden quench (large velocities) when the system is essentially frozen to its initial state; and an intermediate one, where the entropy starts growing linearly but then displays oscillations (also as a function of the velocity). Finally, we discussed the Kibble-Zurek mechanism for the transition between the paramagnetic and the ordered phase.

Caratterizzazione e progettazione di un sistema di comunicazione con ultra low power long range transceiver

Lo sviluppo di nuove tecnologie sempre più innovative e all’avanguardia ha portato ad un processo di costante rivisitazione e miglioramento di sistemi tecnologici già esistenti. L’esempio di Internet risulta, a questo proposito, interessante da analizzare: strumento quotidiano ormai diventato alla portata di tutti, il suo processo di rivisitazione ha portato allo sviluppo dell’Internet Of Things (IoT), neologismo utilizzato per descrivere l'estensione di Internet a tutto ciò che può essere trasformato in un sistema elettronico, controllato attraverso la rete mondiale che oggi può essere facilmente fruibile grazie all’utilizzo di Smartphone sempre più performanti. Lo scopo di questa grande trasformazione è quello di creare una rete ad-hoc (non necessariamente con un accesso diretto alla rete internet tramite protocolli wired o wireless standard) al fine di stabilire un maggior controllo ed una maggiore sicurezza, alla quale è possibile interfacciare oggetti dotati di opportuni sensori di diverso tipo, in maniera tale da condividere dati e ricevere comandi da un operatore esterno. Un possibile scenario applicativo della tecnologia IoT, è il campo dell'efficienza energetica e degli Smart Meter. La possibilità di modificare i vecchi contatori del gas e dell’acqua, tutt’oggi funzionanti grazie ad una tecnologia che possiamo definire obsoleta, trasformandoli in opportuni sistemi di metring che hanno la capacità di trasmettere alla centrale le letture o i dati del cliente, di eseguire operazioni di chiusura e di apertura del servizio, nonché operazioni sulla valutazione dei consumi, permetterebbe al cliente di avere sotto controllo i consumi giornalieri. Per costruire il sistema di comunicazione si è utilizzato il modem Semtech SX1276, che oltre ad essere low-power, possiede due caratteristiche rivoluzionarie e all’avanguardia: utilizza una modulazione del segnale da trasmettere innovativa e una grande capacità di rilevare segnali immersi in forti fonti di rumore ; la possibilità di utilizzare due frequenze di trasmissione diverse, 169 MHz e 868MHz.