Acceleration with Self-Injection for an All-Optical Radiation Source at LNF

We discuss a new compact gamma-ray source aiming at high spectral density, up to two orders of magnitude higher than currently available bremsstrahlung sources, and conceptually similar to Compton Sources based on conventional linear accelerators. This new source exploits electron bunches from laser-driven electron acceleration in the so-called self-injection scheme and uses a counter-propagating laser pulse to obtain X and gamma-ray emission via Thomson/Compton scattering. The proposed experimental configuration inherently provides a unique test-bed for studies of fundamental open issues of electrodynamics. In view of this, a preliminary discussion of recent results on self-injection with the FLAME laser is also given.Comment: 8 pages, 10 figures, 44 references - Channeling 2012 conferenc

Spatial correlations in hexagons generated via a Kerr nonlinearity

We consider the hexagonal pattern forming in the cross-section of an optical beam produced by a Kerr cavity, and we study the quantum correlations characterizing this structure. By using arguments related to the symmetry broken by the pattern formation, we identify a complete scenario of six-mode entanglement. Five independent phase quadratures combinations, connecting the hexagonal modes, are shown to exhibit sub-shot-noise fluctuations. By means of a non-linear quantum calculation technique, quantum correlations among the mode photon numbers are demonstrated and calculated.Comment: ReVTeX file, 20 pages, 7 eps figure

Attosecond electronic and nuclear quantum photodynamics of ozone: time-dependent Dyson orbitals and dipole

A nonadiabatic scheme for the description of the coupled electron and nuclear motions in the ozone molecule was proposed recently. An initial coherent nonstationary state was prepared as a superposition of the ground state and the excited Hartley band. In this situation neither the electrons nor the nuclei are in a stationary state. The multiconfiguration time dependent Hartree method was used to solve the coupled nuclear quantum dynamics in the framework of the adiabatic separation of the time-dependent Schr\"odinger equation. The resulting wave packet shows an oscillation of the electron density between the two chemical bonds. As a first step for probing the electronic motion we computed the time-dependent molecular dipole and the Dyson orbitals. The latter play an important role in the explanation of the photoelectron angular distribution. Calculations of the Dyson orbitals are presented both for the time-independent as well as the time-dependent situations. We limited our description of the electronic motion to the Franck-Condon region only due to the localization of the nuclear wave packets around this point during the first 5-6 fs

When a leader job resource can be ambivalent or even destructive: Independence at work as a double-edged sword

<div><p>Independence at work is commonly considered a job resource which fosters motivation and employee well-being. Somewhat paradoxically, it is embedded in a relationship, and employees’ independence also hinges on their leaders’ willingness to grant it. Analyzing this resource as part of the leader-follower relationship can be useful in exploring its beneficial, ambivalent, or detrimental reciprocal effects. We present two Actor-Partner Interdependence Models (APIM) which analyze leaders’ and followers’ independence as antecedents, and work engagement and emotional exhaustion as outcomes. We test our models on 112 pairs of UK workers, finding a significant partner effect between leaders’ independence and followers’ exhaustion. Our findings confirm the utility of a dyadic perspective for investigating leadership and well-being at work, and suggest improvements for leadership training and measures fostering job well-being.</p></div

From Natural Woods to High Density Materials: An Ecofriendly Approach

Densified wood are a woody materials which an increase in density and mechanical properties. The materials obtained in this work, using less pollutant reagents, showed an increase in density from 200% to 400%. The characterizations determine the chemical and structural change compositions after every step. These characterizations showed how different woods have comparable densities and final mechanical properties (+300% the initial one) after densification process

Cardiovascular magnetic resonance (CMR) in restrictive cardiomyopathies

The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated

On the gas storage properties of 3D porous carbons derived from hyper-crosslinked polymers

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 degrees C, and chemical activation with KOH followed by thermal treatment at 750 or 800 degrees C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 degrees C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volumethe textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m(2)/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed

Anthocyanin and aroma profiling of the 'Albarossa' grapevine crossbreed (Vitis vinifera L.) and its parent varieties 'Barbera' and 'Nebbiolo di Dronero'

V. vinifera L. 'Barbera', 'Nebbiolo di Dronero' and the crossbreed 'Albarossa', grown in Piedmont region, Italy, were characterized by the analysis of grape anthocyanins, using High Performance Liquid Chromatography (HPLC), and aromatic compounds using Gas Chromatography coupled with Mass Spectrometry (GC-MS). Five monomeric non-acylated anthocyanins, delphinidin-3-monoglucoside, cyanidin-3-monoglucoside, petunidin-3-monoglucoside, peonidin-3-monoglucoside, malvidin-3-monoglucoside, and the pool of acetic acid acylated anthocyanins and coumarate/caffeoate anthocyanins were detected, as well as the concentration of terpenes, norisoprenoids, alcohols and benzene compounds. Ratios between the different anthocyanin forms were used for varietal profiling, as well as ratios and concentrations of single or pooled aromatic compounds. 'Albarossa' had intermediate levels, between 'Barbera' and 'Nebbiolo di Dronero', of certain anthocyanins and aromas, due to the genetic relationships. &nbsp