Search results for " Structure"
showing 10 items of 25475 documents
Tin resonance-ionization schemes for atomic- And nuclear-structure studies
2020
This paper presents high-precision spectroscopic measurements of atomic tin using five different resonance-ionization schemes performed with the collinear resonance-ionization spectroscopy technique. Isotope shifts were measured for the stable tin isotopes from the $5{s}^{2}5{p}^{2}\phantom{\rule{0.28em}{0ex}}^{3}{P}_{0,1,2}$ and ${}^{1}{S}_{0}$ to the $5{s}^{2}5p6s\phantom{\rule{0.28em}{0ex}}^{1}{P}_{1},^{3}{P}_{1,2}$ and $5{s}^{2}5p7s{\phantom{\rule{0.28em}{0ex}}}^{1}{P}_{1}$ atomic levels. The magnetic dipole hyperfine constants ${A}_{\mathrm{hf}}$ have been extracted for six atomic levels with electron angular momentum $Jg0$ from the hyperfine structures of nuclear spin $I=1/2$ tin isot…
Spectroscopy of short-lived radioactive molecules
2020
Molecular spectroscopy offers opportunities for the exploration of the fundamental laws of nature and the search for new particle physics beyond the standard model1–4. Radioactive molecules—in which one or more of the atoms possesses a radioactive nucleus—can contain heavy and deformed nuclei, offering high sensitivity for investigating parity- and time-reversal-violation effects5,6. Radium monofluoride, RaF, is of particular interest because it is predicted to have an electronic structure appropriate for laser cooling6, thus paving the way for its use in high-precision spectroscopic studies. Furthermore, the effects of symmetry-violating nuclear moments are strongly enhanced5,7–9 in molecu…
Cross validation of hard-copy and web-based formats of the Sport Imagery Ability Measure
2018
The purpose of this multi-sample study was to examine the psychometric characteristics, factor structure, and measurement invariance of the hard-copy and web-based versions of a measure of sport imagery ability, termed Sport Imagery Ability Measure (SIAM). In the first sample, Spanish athletes (N = 274, 161 men, 113 women, Mage = 21.91, SD = 6.67) completed a hard-copy version of the SIAM. A newly developed web-based version of the SIAM was cross validated in an independent group (N = 266, 147 men, 119 women, Mage = 25.93, SD = 9.84). A small group of participants (n = 16) completed both versions. Exploratory structural equation modelling and confirmatory factor analysis of the data from th…
Stochastic gravito-inertial modes discovered by CoRoT in the hot Be star HD 51452
2012
International audience; Context. Be stars are rapidly rotating stars with a circumstellar decretion disk. They usually undergo pressure and/or gravity pulsation modes excited by the κ-mechanism, i.e. an effect of the opacity of iron-peak elements in the envelope of the star. In the Milky Way, p-modes are observed in stars that are hotter than or equal to the B3 spectral type, while g-modes are observed at the B2 spectral type and cooler. Aims. We observed a B0IVe star, HD 51452, with the high-precision, high-cadence photometric CoRoT satellite and high-resolution, ground-based HARPS and SOPHIE spectrographs to study its pulsations in great detail. We also used the lower resolution spectra a…
The ALHAMBRA survey: evolution of galaxy clustering since z∼1
2014
We study the clustering of galaxies as function of luminosity and redshift in the range $0.35 < z < 1.25$ using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover $2.38 \mathrm{deg}^2$ in 7 independent fields, after applying a detailed angular selection mask, with accurate photometric redshifts, $��_z \lesssim 0.014 (1+z)$, down to $I_{\rm AB} < 24$. Given the depth of the survey, we select samples in $B$-band luminosity down to $L^{\rm th} \simeq 0.16 L^{*}$ at $z = 0.9$. We measure the real-space clustering using the projected correlation function, accounting for photometric redshifts uncert…
THE ALHAMBRA SURVEY: EVOLUTION OF GALAXY SPECTRAL SEGREGATION
2016
arXiv:1601.03668v1
Measuring galaxy segregation with the mark connection function
2010
(abridged) The clustering properties of galaxies belonging to different luminosity ranges or having different morphological types are different. These characteristics or `marks' permit to understand the galaxy catalogs that carry all this information as realizations of marked point processes. Many attempts have been presented to quantify the dependence of the clustering of galaxies on their inner properties. The present paper summarizes methods on spatial marked statistics used in cosmology to disentangle luminosity, colour or morphological segregation and introduces a new one in this context, the mark connection function. The methods used here are the partial correlation functions, includi…
Interventi migliorativi in acciaio a tutela delle opere di interesse storico-monumentale dal rischio sismico
2007
The research concerns the analysis of structural behaviour of some historic-monumental buildings in which steel structures are used for the seismic protection. A dynamic model has been made to individuate the macro-element with an high seismic risk, that is, for church studied, the drum-dome system. Then a scaled model has been tested to determinate the evolution of the lesions, the retrofitting works, that are constituted by steel frames, bare or braced, inserted inside door/window holes of the drum-dome system, and the variation structural ductility. An elastic linear analysis, with a FEM software, has been developed for other type of buildings, in which the vertical structures are made w…
Progetto di Strutture in acciaio per le nuove costruzioni e per gli interventi di consolidamento. IV Edizione
2005
The book is a state of the art summary of recent development in the behavior, analysis and design of steel and composite structures. The book provides advanced students, researchers al professionals in civil and structural engineering with the basic principles upon which the modern codes are based. In the first part, the materials, the actions and the sectional behavior are analyzed on the base of the limit state theory. Then the connections (bolted and welded)and the stability effects are examined. In this way is possible speak about seismic performance, retrofitting an refurbishment of existing buildings, referring to the italian rules, to the european codes EC3, EC4 and to the AISC rules.
Optical quality of hyperopic and myopic phakic intraocular lenses
2013
Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…