Search results for "Sky"
showing 10 items of 1603 documents
Recovery of rescuers from a 24-h shift and its association with aerobic fitness.
2017
Objectives: Rescuers work in 24-h shifts and the demanding nature of the occupation requires adequate recovery between work shifts. The purpose of this study has been to find out what kind of changes in autonomic control may be seen during work shift and its recovery period in the case of rescuers. An additional interest has been to see if aerobic fitness is associated with recovery from work shifts. Material and Methods: Fourteen male rescuers (aged 34±9 years old) volunteered to participate in the study. Heart rate variability (HRV) was recorded for 96 h to study stress and recovery, from the beginning of a 24-h work shift to the beginning of the next shift. Aerobic fitness assessment inc…
If you drink, don't smoke : Joint associations between risky health behaviors and labor market outcomes
2018
This paper examines the links between risky health behaviors and labor market success. We provide new evidence on the joint relationships between the most prominent forms of risky health behavior - alcohol consumption, smoking and physical inactivity - and long-term labor market outcomes. We use twin data for Finnish men and women linked to register-based individual information on earnings and labor market attachment. The twin data allow us to account for shared family and environmental factors and to measure risky health behaviors in 1975 and 1981. The long-term labor market outcomes were measured in adulthood as an average over the period 1990-2009. The sample sizes are 2156 and 2498 twin…
Learning and the Price Dynamics of a Double-Auction Financial Market with Portfolio Traders
2006
In this paper we study the dynamics of price adjustments in an artificial market where portfolio traders with bounded rationality and limited resources interact through a continuous, electronic open book. The present work extends the model developed in [? ] introducing endogenous target individual portfolio holdings. We model the agents’ order-flow investment decision as an optimal choice given individual characteristics and the available information. We depart from the standard asset pricing framework in two ways. First, we assume that investors have imperfect information about the returns distribution. In particular, we assume that agents hold arbitrary priors about securities’ returns, w…
Le metamorfosi del corale "Vom Himmel hoch da komm ich her" fra Lutero, Bach e Stravinsky
2020
Il corale matalizio "Vom Himmel hoch da komm ich her" (Dall'alto dei cieli io giungo) è stato realizzato da Martin Lutero sulla base della melodia popolare "Ich komm aus fremden Landen her" e fu pubblicato per la prima volta a Wittenberg nel 1535. Assai diffuso in tutta l'area culturale tedesca, questo brano è stato ripreso, tra gli altri, anche da J.S. Bach, sia nel "Weinachts-Oratorium" BWV 248 che nelle "Canonische Veraenderungen" per organo BWV 796 e 796a. Il saggio ricostruisce il contesto in cui vide la luce la versione originale del canto natalizio e si sofferma sull'interesse di Bach per la numerologia e sulle "citazioni nascoste" in molte sue opere, incluse le "Veraenderungen" sul …
Musica e architettura. Le opere di Igor Stravinsky per la basilica di San Marco a Venezia
2019
Il 13 settembre 1956, Stravinsky diresse nella basilica di San Marco a Venezia la prima esecuzione del "Canticum Sacrum" (1955), insieme con le "Variazioni-corali sulla canto natalizio Vom Himmel hoch…" (1955-56). Il "Canticum" era stato realizzato su commissione del Festival delle Biennale e costituisce un esempio dell'approccio del compositore alla tecnica dodecafonica. Le "Variazioni-corali" presentano quasi il medesimo organico del "Canticum" e sono invece da considerarsi come una sorta di ripensamento creativo delle "Variazioni canoniche" BWV 796-796a di Johann Sebastian Bach. September 13th 1956, Stravinsky conducted at the basilica of St. Mark in Venice the first performance of the "…
Interfacial Dzyaloshinskii-Moriya interaction and chiral magnetic textures in a ferrimagnetic insulator
2019
The interfacial Dzyaloshinskii-Moriya interaction (DMI) in multilayers of heavy metal and ferromagnetic metals enables the stabilization of novel chiral spin structures such as skyrmions. Magnetic insulators, on the other hand can exhibit enhanced dynamics and properties such as lower magnetic damping and therefore it is of interest to combine the properties enabled by interfacial DMI with insulating systems. Here, we demonstrate the presence of interfacial DMI in heterostructures that include insulating magnetic layers. We use a bilayer of perpendicularly magnetized insulating thulium iron garnet (TmIG) and the heavy metal platinum, and find a surprisingly strong interfacial DMI that, comb…
Large Dzyaloshinskii-Moriya interaction and room-temperature nanoscale skyrmions in CoFeB/MgO heterostructures
2021
Summary Magnetic skyrmions in heavy metal (HM)/CoFeB/MgO structures are of particular interest for skyrmion-based magnetic tunnel junction (MTJ) devices because of their reliable generation, stability, and readout through purely electrical methods. To optimize the properties, such as stability, a strong Dzyaloshinskii-Moriya interaction (DMI) is required at room temperature. Here, using first-principles calculations, we demonstrate that huge DMI can be obtained in Ir/CoFe structures with an Fe-terminated configuration. Moreover, Brillouin light-scattering measurements show that indeed Ta/Ir/Co20Fe60B20/MgO thin films with perpendicular magnetic anisotropy exhibit a large DMI value (1.13 mJ/…
Mechanism for ultrafast electric-field driven skyrmion nucleation
2021
We show how a Dzyaloshinskii-Moriya interaction can be generated in an ultrathin metal film from a femtosecond pulse in electric field. This interaction does not require structural inversion-symmetry breaking, and its amplitude can be tuned depending on the amplitude of the field. We perform first-principles calculations to estimate the strength of the field-induced magnetoelectric coupling for ferromagnetic Fe, Co, and Ni, and antiferromagnetic Mn, as well as FePt and MnPt alloys. Last, using atomistic simulations, we demonstrate how an isolated antiferromagnetic skyrmion can be coherently nucleated from the collinear background by an ultrashort pulse in electric field on a hundred-femtose…
Magnetic Skyrmions: Current-Induced Skyrmion Generation through Morphological Thermal Transitions in Chiral Ferromagnetic Heterostructures (Adv. Mate…
2018
Current-Induced Skyrmion Generation through Morphological Thermal Transitions in Chiral Ferromagnetic Heterostructures.
2018
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Magnetic skyrmions promise breakthroughs in future memory and computing devices due to their inherent stability and small size. Their creation and current driven motion have been recently observed at room temperature, but the key mechanisms of their formation are not yet well-understood. Here it is shown that in heavy metal/ferromagnet heterostructures, pulsed currents can drive morphological transitions between labyrinth-like, stripe-like, and skyrmionic states. Using high-resolution X-ray microscopy, the spin texture evolution with temperature and magnetic field is imaged and it is demonstrated that with transient Joule heating, topologica…