Search results for "fields"
showing 10 items of 575 documents
Pesticide contamination in water and sediment of the aquatic systems of the Natural Park of the Albufera of Valencia (Spain) during the rice cultivat…
2021
The Natural Park of the Albufera (Valencia, Spain) is a Mediterranean wetland where rice cultivation dominates the agricultural activity. The purpose of this study was to offer broader information about the current state of the wetland assessing the contamination by pesticides in four aquatic habitats during the rice cultivation period in 2016. Liquid chromatography with tandem mass spectrometer (UHPLC-MS/MS) was used to determine the pesticides in water and sediment samples from the rice fields, Lake Albufera and irrigation and outlet channels. 21 pesticides were detected in our samples (seven already forbidden by European legislation). Higher values than 10000 ng L of accumulated pesticid…
La globalización del Geoforo Iberoamericano en 2018
2018
Los diez años de existencia del Geoforo Iberoamericano (geoforo.blogspot. com) nos permiten hacer un balance del trabajo realizado y valorar su presencia en el mundo global de las redes sociales. Las relaciones que se han establecido entre el profesorado y alumnado de geografía han superado las fronteras iniciales. Ya no solo es el mundo iberoamericano, sino que el Geoforo ha tenido presencia en otras escalas planetarias. Igualmente, el campo de la enseñanza de la geografía se ha ampliado a los ámbitos del conocimiento de la didáctica de las ciencias sociales. El éxito o fracaso del Geoforo reside en la fortaleza de las relaciones sociales que se han establecido entre el profesorado y alumn…
Machine Learning-Based View Synthesis in Fourier Lightfield Microscopy
2022
Current interest in Fourier lightfield microscopy is increasing, due to its ability to acquire 3D images of thick dynamic samples. This technique is based on simultaneously capturing, in a single shot, and with a monocular setup, a number of orthographic perspective views of 3D microscopic samples. An essential feature of Fourier lightfield microscopy is that the number of acquired views is low, due to the trade-off relationship existing between the number of views and their corresponding lateral resolution. Therefore, it is important to have a tool for the generation of a high number of synthesized view images, without compromising their lateral resolution. In this context we investigate h…
Multiwavelength monitoring of BD+53°2790 , the optical counterpart to 4U 2206+54
2005
We present the results of our long-term monitoring of BD+53 2790, the optical counterpart to the X-ray source 4U~2206+54. Unlike previous studies that classify the source as a Be/X-ray binary, we find that its optical and infrared properties differ from those of typical Be stars: the variability of the V/R ratio is not cyclical; there are variations in the shape and strength of the H$\alpha$ emission line on timescales less than 1 day; and no correlation between the EW and the IR magnitudes or colors is seen. Our observations suggest that BD+53 2790 is very likely a peculiar O9.5V star. In spite of exhaustive searches we cannot find any significant modulation in any emission line parameter …
Wannier90 as a community code: new features and applications
2019
Wannier90 is an open-source computer program for calculating maximally-localised Wannier functions (MLWFs) from a set of Bloch states. It is interfaced to many widely used electronic-structure codes thanks to its independence from the basis sets representing these Bloch states. In the past few years the development of Wannier90 has transitioned to a community-driven model; this has resulted in a number of new developments that have been recently released in Wannier90 v3.0. In this article we describe these new functionalities, that include the implementation of new features for wannierisation and disentanglement (symmetry-adapted Wannier functions, selectively-localised Wannier functions, s…
Magnetic field-controlled 0−π transitions and their experimental signatures in superconductor-ferromagnet-superconductor junctions
2019
Superconductor-ferromagnet-superconductor Josephson junctions are known to exist in the $0$ and $\pi$ states with the transitions between them controlled by the temperature and ferromagnetic interlayer thickness. We demonstrate that these transitions can be controlled also by the external magnetic field directed perpendicular to the layers. By varying the ratio of diffusion coefficients in superconducting and ferromagnetic layers, these field-controlled transitions can be made detectable for arbitrary large value of the exchange energy in the ferromagnet. We also show that the $0$-$\pi$ transitions in the perpendicular field can be observed as the specific features of the flux-flow conducti…
Women in physics: A comparison to science, technology, engineering, and math education over four decades
2016
[This paper is part of the Focused Collection on Gender in Physics.] The dearth of women in science, technology, engineering, and math (STEM) fields has been lamented by scholars, administrators, policymakers, and the general public for decades, and the STEM gender gap is particularly pronounced in physics. While previous research has demonstrated that this gap is largely attributable to a lack of women pursuing physics in college, prior research reveals little in terms of the characteristics and career interests of women who do plan to major in physics or how these traits have evolved over time. To address these gaps, this study utilized nationwide data on first-time, full-time college stu…
RELATIVISTIC COMPRESSION AND EXPANSION OF EXPERIENTIAL TIME IN THE LEFT AND RIGHT SPACE
2007
Time, space and numbers are closely linked in the physical world. However, the relativistic-like effects on time perception of spatial and magnitude factors remain poorly investigated. Here we wanted to investigate whether duration judgments of digit visual stimuli are biased depending on the side of space where the stimuli are presented and on the magnitude of the stimulus itself. Different groups of healthy subjects performed duration judgment tasks on various types of visual stimuli. In the first two experiments visual stimuli were constituted by digit pairs (1 and 9), presented in the centre of the screen or in the right and left space. In a third experiment visual stimuli were constitu…
Non-London electrodynamics in a multiband London model : anisotropy-induced nonlocalities and multiple magnetic field penetration lengths
2018
The London model describes strongly type-2 superconductors as massive vector field theories, where the magnetic field decays exponentially at the length scale of the London penetration length. This also holds for isotropic multi-band extensions, where the presence of multiple bands merely renormalises the London penetration length. We show that, by contrast, the magnetic properties of anisotropic multi-band London models are not this simple, and the anisotropy leads to the inter-band phase differences becoming coupled to the magnetic field. This results in the magnetic field in such systems having N+1 penetration lengths, where N is the number of field components or bands. That is, in a giv…
Coordination isomerism in spin crossover (SCO) materials
2021
International audience; A new series of three spin crossover (SCO) Fe(II) complexes based on a cyanocarbanion and on the neutral quinolin-8-amine (aqin) ligands, [Fe(aqin)2(tcnsme)2] (1), [Fe(aqin)2(tcnset)2] (2), and [Fe(aqin)2(tcnspr)2] (3), has been studied. The three complexes display similar molecular structures consisting of discrete [Fe(aqin)2(tcnsR)2] complexes [R = Me (1), Et (2), and Pr (3)]. Infrared spectroscopy and magnetic studies, performed on the three complexes, revealed the presence of similar SCO behaviors which strongly differ by their transition temperatures [234 K (1) < 266 K (2) < 360 K (3)]. The increase of the transition temperatures when passing from 1 to 3 may be …