A new concept of obtaining red emission in solid-state LED devices based on material composition was proposed. Gd3Ga5O12 (GGG) luminescent compounds doped with both Pr3+ and Ce3+ ions were ...synthetized. Positions of f-d bands were assigned. Increase of the 1D2 praseodymium red luminescence intensity following the increase of Ce3+ concentration was observed. However, participation of the energy transfer from d levels of Ce3+ to Pr3+ was ruled out. Decay curves of the luminescence originating from the 1D2 and 3P0 multiplets in both GGG:Pr and GGG:Pr + Ce were analyzed as the function of dopants concertation. For diluted Pr3+ they reach ca. 230 and 24 μs Nonexponential character of Pr3+ decay curves was observed. The concentration quenching mechanisms were determined. The quadrupole-quadrupole mechanism of changing the emission color to orange-red in Ce + Pr system may suggest that in this process, more than one of cerium ions take part simultaneously.
A new concept of low cost improving of orange-red luminescence has been presented. Ce3+ concentrations were changed in the range of 0–4.9 at.%. The concentration of Pr3+ is 0.1 at.%. Display omitted
•Novel orange-red phosphor has been synthesized.•Energy transfer processes and quenching mechanism have been appointed.•The influence of concentration on the transition ratio has been given.•The energy transfer from Ce3+ to Pr3+ has been excluded.
•Degeneracy supports stability and flexibility in perception-action systems.•Affordance utilization can support the emergence of degenerate behaviors.•Degeneracy supports creativity and evolvability ...in neurobiological systems.•Design of learning needs to allow system degeneracy to be exploited.
A crucial aspect of understanding human behavior relates to how perception and action sub-systems are integrated during coordinated and controlled movement in goal-directed activity. Here we discuss how a neurobiological system property, degeneracy (i.e., many coordinative structures to achieve one function), can help us understand how skilled individuals functionally adapt perception and action to interacting constraints during performance. Since most research investigating degeneracy has been conducted in neuroanatomy, genetics and theoretical neurobiology, here we clarify how degeneracy is exhibited in perceptual-motor systems. Using an ecological dynamics framework, we highlight how degeneracy underpins the functional role of movement coordination variability in performance of multi-articular tasks. Following that, we discuss how degenerate neurobiological systems are able to exploit system stability and flexibility in their movement coordination. Third, we show how better coupling of information and movement could lead individuals to explore functionally degenerate behaviors. Last, we explore how degeneracy can support pluri-potentiality (i.e., one coordinative structure for many perceptual-motor functions) as a way toward innovation or refinement in performance.
This study aims to determine the impact of training program to the improvement of teaching competency in Adaptive Physical Education (APE) of special educators. The provided training is ...competency-based and conventional training program. The teaching competency consist of professional and pedagogical of APE. This research using experiment method with factorial model 2X2. The sample are teachers of intellectual disability student. The sampling data collection using stratified cluster random sampling. The samples are 60 teachers divided to four groups that joined 60 hours of training program. The statistical analysis applied with T-Test sample paired test, Anova test (Two Way Anova with Main Effect and Interaction Effect), and PostHoc Test. The results shows that group of teachers in competency-based training program gain a high competency test score, average score higher than other groups. There is no interaction between training program and competency test result to the enhancement of teaching competency in APE.
Dynamic steering of laser beams by ultrathin optical metasurfaces is a significant research advance for possible applications in remote ranging and sensing. A unique platform for such important ...functionalities is offered by dielectric metasurfaces that have the highest transmission efficiency. However, the realization of dynamically tunable metasurfaces still remains a challenge. Here we experimentally demonstrate the dynamic switching of beam deflection by a silicon-nanodisk dielectric metasurface infiltrated with liquid crystals. In particular, we show the switching of a laser beam from 0° to a 12° angle with an efficiency of 50% by heating the metasurface to modify the liquid crystal state from nematic to isotropic. Our results open important opportunities for tunable ultrathin beam steering metadevices.
In vino sanitas Komar, Paulina
Mélanges de l'Ecole française de Rome. Antiquité,
2020
Journal Article
Recenzirano
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This paper explores the issue of medical qualities that were attributed to Greek wines by ancient physicians. It concentrates on the use of different wines as elements of nutritional regimens and as ...ingredients of certain medicines. One of the main purposes of this paper is to demonstrate the impact that Greek medicine had on Roman dietary habits.
A Case Study on the Origin of Near‐Earth Plasma Glocer, A.; Welling, D.; Chappell, C. R. ...
Journal of geophysical research. Space physics,
November 2020, Letnik:
125, Številka:
11
Journal Article
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This study presents simulations of the coupled space environment during a geomagnetic storm that separates the different sources of near‐Earth plasma. These simulations include separate fluids for ...solar wind and ionospheric protons, ionospheric oxygen, and the plasmasphere. Additionally, they include the effects of both a hot ring current population and a cold plasmaspheric population simultaneously for a geomagnetic storm. The modeled ring current population represents the solution of bounce‐averaged kinetic solution; the core plasmaspheric model assumes a fixed temperature of 1 eV and constant pressure along the field line. We find that during the storm, ionospheric protons can be a major contributor to the plasmasheet and ring current and that ionospheric plasma can largely displace solar wind protons in much of the magnetosphere under certain conditions. Indeed, the ionospheric source of plasma cannot be ignored. Significant hemispheric asymmetry is found between the outflow calculated in the summer and winter hemispheres, consistent with past observations. That asymmetric outflow is found to lead to asymmetric filling of the lobes, with the northern (summer) lobe receiving more outflow that has a higher proportion of O+ and the southern (winter) lobe receiving less outflow with a higher proportion of H+. We moreover find that the inclusion of the plasmasphere can have a system‐wide impact. Specifically, when the plasmasphere drainage plume reaches the magnetopause, it can reduce the reconnection rate, suppress ionospheric outflow and change its composition, change the composition in the magnetosphere, and reduce the ring current intensity.
Key Points
Ionospheric H+ is a critically important contributor to the magnetosphere during a storm
Seasonal effect on outflow create asymmetric filling of the lobes
The inclusion of an additional plasmaspheric fluid has system‐wide effects
This article is the first comprehensive examination of Montenegro's interest group system. This system is a product of a combination of traditional influences and recent developments. The major ...traditional influences are a closed, patriarchal society with strong family and kinship relations, and a nonparticipatory political culture. These combined with over a quarter century of dominance by the ex‐communist party have been major impediments to the growth of interest group activity. Despite this, significant developments have occurred in the establishment of new interests and their activities, much of this made possible by the strong presence of various elements of the international community. Nevertheless, Montenegro has a bifurcated interest group system in which a small elite dominates interest group activity, while, for the most part, the mass of society do not participate in political advocacy.
We present an analysis of local properties of magnetic reconnection at the dayside magnetopause for various interplanetary magnetic field (IMF) orientations in global magnetospheric simulations. This ...has heretofore not been practical because it is difficult to locate where reconnection occurs for oblique IMF, but new techniques make this possible. The approach is to identify magnetic separators, the curves separating four regions of differing magnetic topology, which map the reconnection X line. The electric field parallel to the X line is the local reconnection rate. We compare results to a simple model of local two‐dimensional asymmetric reconnection. To do so, we find the plasma parameters that locally drive reconnection in the magnetosheath and magnetosphere in planes perpendicular to the X line at a large number of points along the X line. The global magnetohydrodynamic simulations are from the three‐dimensional Block‐Adaptive, Tree Solarwind Roe‐type Upwind Scheme (BATS‐R‐US) code with a uniform resistivity, although the techniques described here are extensible to any global magnetospheric simulation model. We find that the predicted local reconnection rates scale well with the measured values for all simulations, being nearly exact for due southward IMF. However, the absolute predictions differ by an undetermined constant of proportionality, whose magnitude increases as the IMF clock angle changes from southward to northward. We also show similar scaling agreement in a simulation with oblique southward IMF and a dipole tilt. The present results will be an important component of a full understanding of the local and global properties of dayside reconnection.
Key Points
Identify and measure plasma parameters local to the 3‐D reconnection line in global MHD simulations with oblique IMF and dipole tilt
Calculate 2‐D analytic asymmetric reconnection rates from upstream plasma parameters
Find the measured reconnection rate local to the 3‐D reconnection line scales well with 2‐D analytic predictions for all simulations
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