Far-infrared photometric observations of the outer planets and satellites with Herschel-PACS

We present all Herschel PACS photometer observations of Mars, Saturn, Uranus, Neptune, Callisto, Ganymede, and Titan. All measurements were carefully inspected for quality problems, were reduced in a (semi-)standard way, and were calibrated. The derived flux densities are tied to the standard PACS photometer response calibration, which is based on repeated measurements of five fiducial stars. The overall absolute flux uncertainty is dominated by the estimated 5% model uncertainty of the stellar models in the PACS wavelength range between 60 and 210 micron. A comparison with the corresponding planet and satellite models shows excellent agreement for Uranus, Neptune, and Titan, well within the specified 5%. Callisto is brighter than our model predictions by about 4-8%, Ganymede by about 14-21%. We discuss possible reasons for the model offsets. The measurements of these very bright point-like sources, together with observations of stars and asteroids, show the high reliability of the PACS photometer observations and the linear behavior of the PACS bolometer source fluxes over more than four orders of magnitude (from mJy levels up to more than 1000 Jy). Our results show the great potential of using the observed solar system targets for cross-calibration purposes with other ground-based, airborne, and space-based instruments and projects. At the same time, the PACS results will lead to improved model solutions for future calibration applications.Comment: 25 pages, 11 figures, 11 table

The Virtual Environments and Platforms in the Teaching of English

Abstract The research aims to highlight the significance of virtual learning environments and platforms in promoting cognitive competencies through interactive learning. The objective is to create effective learning environments by utilizing Virtual Learning Environments and implementing platforms to enhance communicative competencies. The methodology employed for this study includes quantitative and qualitative, descriptive, and predictive approaches, using technological innovation through the implementation of the Schoology platform based on the TPACK model. The results of the study indicate that students exhibit high levels of motivation and discernment toward virtual environments, particularly in English classes. Therefore, selecting appropriate didactic resources and incorporating pedagogical mediation is crucial for optimizing learning outcomes. It is essential to educate students on the significance of learning a foreign language and how it can impact the neural structure of the bilingual brain. Virtual environments facilitate interaction between team members, leading to the creation of new networks and learning environments for the development of language and communicative competencies in another language. Keywords: virtual environments, English teaching, technological innovation, TPACK model. Resumen La investigación se enfoca en la importancia de los entornos y plataformas virtuales de aprendizaje porque permiten la interacción para desarrollar competencias cognitivas, para ello el objetivo consiste en generar ambientes de aprendizaje basados en los Entornos Virtuales de Aprendizaje, mediante la implementación de plataformas y fortalecer las competencias comunicativas, con este fin la metodología tiene un enfoque cuantitativo – cualitativo, de naturaleza descriptiva y predictiva desde la innovación tecnológica con la implementación de plataforma Schoology basados en el modelo TPACK. De acuerdo a los resultados, se evidencia que existe un alto discernimiento y motivación de los estudiantes a la implementación de los entornos virtuales, en particular a las clases de inglés. Para lo cual la necesidad de una mediación pedagógica en la selección de los recursos didácticos podría potencializar aún más el aprendizaje, para ello es fundamental hacer comprender a los estudiantes la relevancia de aprender un idioma extranjero y como este cambia en la estructura neuronal y su trascendencia en un cerebro bilingüe. Por tanto, los entornos virtuales promueven la interacción entre equipos de trabajo con la finalidad de generar nuevas redes y ambientes de aprendizaje, para el desarrollo de competencias lingüísticas y comunicativas en otro idioma. Palabras Clave: entornos virtuales, enseñanza inglesa, innovación tecnológica, modelo TPACK

Scattering of surface plasmon polaritons by one-dimensional inhomogeneities

The scattering of surface plasmons polaritons by a one-dimensional defect of the surface is theoretically studied, by means of both Rayleigh and modal expansions. The considered defects are either relief perturbations or variations in the permittivity of the metal. The dependence of transmission, reflection and out-of-plane scattering on parameters defining the defect is presented. We find that the radiated energy is forwardly directed (with respect to the surface plasmon propagation) in the case of an impedance defect. However, for relief defects, the radiated energy may be directed into backward or forward (or both) directions, depending on the defect width.Comment: 10 pages, 5 figures, corrected typos, some minor modifications in figures. Accepted in Phys. Rev.

Experimental Verification of 3D Plasmonic Cloaking in Free-Space

We report the experimental verification of metamaterial cloaking for a 3D object in free space. We apply the plasmonic cloaking technique, based on scattering cancellation, to suppress microwave scattering from a finite-length dielectric cylinder. We verify that scattering suppression is obtained all around the object in the near- and far-field and for different incidence angles, validating our measurements with analytical results and full-wave simulations. Our near-field and far-field measurements confirm that realistic and robust plasmonic metamaterial cloaks may be realized for elongated 3D objects with moderate transverse cross-section at microwave frequencies.Comment: 12 pages, 8 figures, published in NJ

Counting atoms using interaction blockade in an optical superlattice

We report on the observation of an interaction blockade effect for ultracold atoms in optical lattices, analogous to Coulomb blockade observed in mesoscopic solid state systems. When the lattice sites are converted into biased double wells, we detect a discrete set of steps in the well population for increasing bias potentials. These correspond to tunneling resonances where the atom number on each side of the barrier changes one by one. This allows us to count and control the number of atoms within a given well. By evaluating the amplitude of the different plateaus, we can fully determine the number distribution of the atoms in the lattice, which we demonstrate for the case of a superfluid and Mott insulating regime of 87Rb.Comment: 4 pages, 4 figure

Evolutionary dynamics of higher-order interactions in social networks

We live and cooperate in networks. However, links in networks only allow for pairwise interactions, thus making the framework suitable for dyadic games, but not for games that are played in groups of more than two players. Here, we study the evolutionary dynamics of a public goods game in social systems with higher-order interactions. First, we show that the game on uniform hypergraphs corresponds to the replicator dynamics in the well-mixed limit, providing an exact theoretical foundation to study cooperation in networked groups. Secondly, we unveil how the presence of hubs and the coexistence of interactions in groups of different sizes affects the evolution of cooperation. Finally, we apply the proposed framework to extract the actual dependence of the synergy factor on the size of a group from real-world collaboration data in science and technology. Our work provides a way to implement informed actions to boost cooperation in social groups

Anomalous Expansion of Attractively Interacting Fermionic Atoms in an Optical Lattice

Strong correlations can dramatically modify the thermodynamics of a quantum many-particle system. Especially intriguing behaviour can appear when the system adiabatically enters a strongly correlated regime, for the interplay between entropy and strong interactions can lead to counterintuitive effects. A well known example is the so-called Pomeranchuk effect, occurring when liquid 3He is adiabatically compressed towards its crystalline phase. Here, we report on a novel anomalous, isentropic effect in a spin mixture of attractively interacting fermionic atoms in an optical lattice. As we adiabatically increase the attraction between the atoms we observe that the gas, instead of contracting, anomalously expands. This expansion results from the combination of two effects induced by pair formation in a lattice potential: the suppression of quantum fluctuations as the attraction increases, which leads to a dominant role of entropy, and the progressive loss of the spin degree of freedom, which forces the gas to excite additional orbital degrees of freedom and expand to outer regions of the trap in order to maintain the entropy. The unexpected thermodynamics we observe reveal fundamentally distinctive features of pairing in the fermionic Hubbard model.Comment: 6 pages (plus appendix), 6 figure