Search results for "620"
showing 10 items of 203 documents
Quartz resonators for penning traps toward mass spectrometry on the heaviest ions
2020
We report on cyclotron frequency measurements on trapped 206,207Pb+ ions by means of the non-destructive Fourier-transform ion-cyclotron-resonance technique at room temperature. In a proof-of-principle experiment using a quartz crystal instead of a coil as a resonator, we have alternately carried out cyclotron frequency measurements for 206Pb+ and 207Pb+ with the sideband coupling method to obtain 21 cyclotron-frequency ratios with a statistical uncertainty of 6 × 10−7. The mean frequency ratio R¯ deviates by about 2σ from the value deduced from the masses reported in the latest Atomic Mass Evaluation. We anticipate that this shift is due to the ion–ion interaction between the simultaneousl…
Suppression of the vacuum space-charge effect in fs-photoemission by a retarding electrostatic front lens
2021
Review of scientific instruments 92(5), 053703 (2021). doi:10.1063/5.0046567
Compact setup for spin-, time-, and angle-resolved photoemission spectroscopy.
2020
Review of scientific instruments 91(6), 063001 (2020). doi:10.1063/5.0004861
Commissioning of the vacuum system of the KATRIN Main Spectrometer
2016
The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. An integral energy analysis will be performed by an electro-static spectrometer (``Main Spectrometer''), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m[superscript 3], and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips ha…
Sun-induced chlorophyll fluorescence III: benchmarking retrieval methods and sensor characteristics for proximal sensing
2019
[EN] The interest of the scientific community on the remote observation of sun-induced chlorophyll fluorescence (SIF) has increased in the recent years. In this context, hyperspectral ground measurements play a crucial role in the calibration and validation of future satellite missions. For this reason, the European cooperation in science and technology (COST) Action ES1309 OPTIMISE has compiled three papers on instrument characterization, measurement setups and protocols, and retrieval methods (current paper). This study is divided in two sections; first, we evaluated the uncertainties in SIF retrieval methods (e.g., Fraunhofer line depth (FLD) approaches and spectral fitting method (SFM))…
A giant exoplanet orbiting a very-low-mass star challenges planet formation models
2019
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts con…
Towards Understanding the Interconnection between Celestial Pole Motion and Earth’s Magnetic Field Using Space Geodetic Techniques
2021
The understanding of forced temporal variations in celestial pole motion (CPM) could bring us significantly closer to meeting the accuracy goals pursued by the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG), i.e., 1 mm accuracy and 0.1 mm/year stability on global scales in terms of the Earth orientation parameters. Besides astronomical forcing, CPM excitation depends on the processes in the fluid core and the core–mantle boundary. The same processes are responsible for the variations in the geomagnetic field (GMF). Several investigations were conducted during the last decade to find a possible interconnection of GMF changes with the length of day (…
Roux-en-Y Gastric Bypass as an Effective Bariatric Revisional Surgery after Restrictive Procedures
2020
<b><i>Introduction:</i></b> Revisional surgery must be considered when insufficient weight loss is attained or weight is subsequently regained. This study aimed to investigate the value of Roux-en-Y gastric bypass (RYGB) as a revisional procedure after restrictive surgery. <b><i>Materials and Methods:</i></b> An observational, retrospective study including patients initially operated on for morbid obesity with restrictive techniques (vertical-banded gastroplasty [VBG], adjustable gastric band [AGB], and sleeve gastrectomy) and reoperated with RYGB in our centre between December 1994 and January 2019. Demographic and anthropometric data, associ…
DEBATE: Do interventions based on behavioral theory work in the real world?
2019
Abstract Background Behavioral scientists suggest that for behavior change interventions to work effectively, and deliver population-level health outcomes, they must be underpinned by behavioral theory. However, despite implementation of such interventions, population levels of both health outcomes and linked behaviors have remained relatively static. We debate the extent to which interventions based on behavioral theory work in the real world to address population health outcomes. Discussion Hagger argues there is substantive evidence supporting the efficacy and effectiveness of interventions based on behavioral theory in promoting population-level health behavior change in the ‘real world…
Valoración de la efectividad de la educación alimentaria en niños preescolares, padres y educadores
2016
Introducción: La etapa infantil es el momento en el que se desarrollan los factores de riesgo que pueden desencadenar en edades adultas enfermedades relacionadas con la alimentación. Éste es el momento adecuado para instaurar las bases de una alimentación saludable. El objetivo del presente estudio fue evaluar la adherencia a la Dieta Mediterránea de niños, los conocimientos sobre hábitos saludables de niños, padres y profesores antes y después de una intervención de educación alimentaria, así como evaluar su eficacia.Material y Métodos: Estudio transversal en el que participaron 94 estudiantes de edades comprendidas entre 3 y 6 años, 12 padres y 8 profesores. Se calculó el grado de conocim…