7,265 research outputs found
Study of the isotropic contribution to the analysis of photoelectron diffraction experiments at the ALOISA beamline
The angular distribution of the intensity in photoemission experiments is
affected by electron diffraction patterns and by a smoothly varying ISO
contribution originated by both intrumental details and physical properties of
the samples. The origin of the various contributions to the ISO component has
been identified since many years. Nonetheless in this work we present original
developement of the ED analysis, which arises from the evolution of
instrumental performance, in terms of analyzers positioning and angular
resolution, as well as collimation and size of X-ray beams in third generation
synchrotron sources. The analytical treatement of the instrumental factors is
presented in detail for the end station of the ALOISA beamline (Trieste
Synchrotron), where a wide variety of scattering geometries is available for ED
experiments. We present here the basic formulae and their application to
experimental data taken on the Fe/Cu3Au(001) system in order to highlight the
role of the various parameters included in the distribution function. A
specific model for the surface illumination has been developed as well as the
overlayer thickness and surface roughness have been considered.Comment: RevTex, nine pages with five eps figures; to be published in J.
Electron Spectrosc. Relat. Pheno
Monitoring the solid-state dewetting of densely packed arrays of Au nanoparticles
We report a real time, in-situ spectroscopic ellipsometry study of the temperature-induced solid-state dewetting of Au nanowires into nanoparticles. Very large spectral variations are observed at different temperatures. Analysis of the key features in the acquired spectra reveals two different regimes: up to 300 \ub0C the variation in the optical response is dominated by solid-state dewetting, while above that temperature, smaller variations not compatible with such mechanism are visible. Therefore our ellipsometry measurements allow us to determine in real time at which temperature the solid-state dewetting ceases and the morphology of our sample becomes stable. We point out that this observation is possible thanks to the higher sensitiviy of ellipsometry with respect to reflectance/transmittance measurements
Architecture, science and exhibit: yesterday and today
Architecture and science have always been interrelated for educational purposes. For this reason the course of Interior Architecture and Exhibit Design at Master of Science in Architecture Construction City of Politecnico di Torino, starting from the knowledge of the role of the Academy and its scientific content, proposed new and current forms of exhibits and communication in respect of the courtly architecture that is called to emphasize with its language the authority and perennial values of the sciences
Age Discrimination in Employment: A Comparison of the Federal and State Laws and Remedies in New Mexico
Pulmonary and cardiac drugs: clinically relevant interactions
Chronic heart and lung diseases are very common in the elderly population. The combination of chronic heart failure and chronic obstructive pulmonary disease (COPD) is also common and, according to current guidelines, these patients should be treated for both diseases. In patients with heart failure, beta-blockers are very important drugs because their use is associated with significantly improved morbidity and mortality. These beneficial effects were documented in patients with and without COPD, although theoretically there is a risk for bronchoconstriction, particularly with non-beta1 selective blockers. In COPD patients, long-acting sympathomimetics (LABA) improve lung function, dyspnea, and quality of life and their combination with a beta-blocker makes sense from a pharmacological and a clinical point of view, because any potential arrhythmogenic effects of the LABA will be ameliorated by the beta-blocker. Inhaled tiotropium, a long-acting muscarinic antagonist (LAMA), has been extensively investigated and no safety concerns were reported in terms of cardiac adverse effects. The same applies for the other approved LAMA preparations and LAMA-LABA combinations. Severe COPD causes air-trapping with increasing pressures in the thorax, leading to limitations in blood return into the thorax from the periphery of the body. This causes a decrease in stroke volume and cardiac index and is associated with dyspnea. All these adverse effects can be ameliorated by potent anti-obstructive therapy as recently shown by means of a LABA-LAMA combination
Advancements in the Investigation of Vertical Profiles of Thunderstorm Outflows
The dynamic complexity and unpredictability of the occurrence of thunderstorms
make it difficult to collect reliable and systematic measurements of this atmospheric phenomenon, which are definitely needed to evaluate its action on structures. The area of the Northern Tyrrhenian Sea is a \u201chot-spot\u201d for the genesis of severe potentially damaging wind phenomena, such as downbursts, whose occurrence in this geographical region is not well documented. In the context of the two European projects \u201cWind and Ports\u201d and \u201cWind, Ports and Sea\u201d, a large and complex wind monitoring network has been installed in this area. Since the years 2014-2015, this network is equipped with three LiDAR profilers which provide vertical scanning of the atmosphere up to 250 m above the ground level. All the wind profiles have been systematically analysed in order to detect the ones that can be referred to thunderstorm events. The aim of this study is to extend a first set of analyses up to mid-2018 to provide a preliminary investigation of the main parameters describing the non-synoptic events and a first classification of thunderstorm events into different subsets
Surfactant-like Effect and Dissolution of Ultrathin Fe Films on Ag(001)
The phase immiscibility and the excellent matching between Ag(001) and
Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field
of low dimensionality magnetic systems. Intermixing could be drastically
limited at deposition temperatures as low as 140-150 K. The film structural
evolution induced by post-growth annealing presents many interesting aspects
involving activated atomic exchange processes and affecting magnetic
properties. Previous experiments, of He and low energy ion scattering on films
deposited at 150 K, indicated the formation of a segregated Ag layer upon
annealing at 550 K. Higher temperatures led to the embedding of Fe into the Ag
matrix. In those experiments, information on sub-surface layers was attained by
techniques mainly sensitive to the topmost layer. Here, systematic PED
measurements, providing chemical selectivity and structural information for a
depth of several layers, have been accompanied with a few XRD rod scans,
yielding a better sensitivity to the buried interface and to the film long
range order. The results of this paper allow a comparison with recent models
enlightening the dissolution paths of an ultra thin metal film into a different
metal, when both subsurface migration of the deposit and phase separation
between substrate and deposit are favoured. The occurrence of a surfactant-like
stage, in which a single layer of Ag covers the Fe film is demonstrated for
films of 4-6 ML heated at 500-550 K. Evidence of a stage characterized by the
formation of two Ag capping layers is also reported. As the annealing
temperature was increased beyond 700 K, the surface layers closely resembled
the structure of bare Ag(001) with the residual presence of subsurface Fe
aggregates.Comment: 4 pages, 3 figure
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