1,032 research outputs found
Optimizing Mathematical Morphology for Image Segmentation and Vision-based Path Planning in Robotic Environments
Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures
A compact cryogenic Kerr microscope for operation in the small volume of
high-field magnets is described. It is suited for measurements both in Voigt
and Faraday configuration. Coupled with a pulsed laser source, the microscope
is used to measure the time-resolved Kerr rotation response of semiconductor
microstructures with ~1 micron spatial resolution. The microscope was designed
to study spin transport, a critical issue in the field of spintronics. It is
thus possible to generate spin polarization at a given location on a
microstructure and probe it at a different location. The operation of the
microscope is demonstrated by time-resolved measurements of micrometer distance
diffusion of spin polarized electrons in a GaAs/AlGaAs heterojunction quantum
well at 4.2 K and 7 Tesla
A Brauer--Galois height zero conjecture
Recently, Malle and Navarro obtained a Galois strengthening of Brauer's
height zero conjecture for principal -blocks when , considering a
particular Galois automorphism of order~. In this paper, for any prime
we consider a certain elementary abelian -subgroup of the absolute Galois
group and propose a Galois version of Brauer's height zero conjecture for
principal -blocks. We prove it when and also for arbitrary when
does not involve certain groups of Lie type of small rank as composition
factors. Furthermore, we prove it for almost simple groups and for -solvable
groups.Comment: a few minor improvements over version
Suppressed spin dephasing for 2D and bulk electrons in GaAs wires due to engineered cancellation of spin-orbit interaction terms
We report a study of suppressed spin dephasing for quasi-one-dimensional
electron ensembles in wires etched into a GaAs/AlGaAs heterojunction system.
Time-resolved Kerr-rotation measurements show a suppression that is most
pronounced for wires along the [110] crystal direction. This is the fingerprint
of a suppression that is enhanced due to a strong anisotropy in spin-orbit
fields that can occur when the Rashba and Dresselhaus contributions are
engineered to cancel each other. A surprising observation is that this
mechanisms for suppressing spin dephasing is not only effective for electrons
in the heterojunction quantum well, but also for electrons in a deeper bulk
layer.Comment: 5 pages, 3 figure
Funciones cognitivas afectadas en paciente con ACV
El objetivo de este estudio consiste en determinar el perfil neuropsicológico en pacientes que han sufrido un accidente cerebrovascular y su impacto psicosocial. Se realizó un estudio descriptivo, bajo el enfoque empírico analítico; se hizo una evaluación neuropsicológica transversal en 3 pacientes de ambos géneros, entre 20 y 69 años del departamento de Rawson, en la ciudad de San Juan, que han sido diagnosticados en Centro Integral de Rehabilitación con ACV isquémico y en otros casos hemorrágico, con estudios de neuroimagen que así lo confirmaron.
Se realizó un análisis sobre la base de un procedimiento clínico. Se encontró síndromes neuropsicológicos como, afasia, agnosia, apraxia gestual y heminegligencia. No se pudo establecer un cuadro sintomatológico único debido a la heterogeneidad de las lesiones que causa el cuadro. Se comprobó la incidencia del contexto familiar en el desarrollo del proceso de neurorehabilitación, así como el impacto en la estructura familiar que provoca la situación de discapacidad del paciente que ha sufrido un accidente cerebro vascular.Fil: Rizo Saffe, Valeria A
Impact of texture TDS and flavour TDS tasks and of chocolate-chip biscuit characteristics on oral processing features
[EN] The objective of the present study was to investigate differences in oral activity when biscuits of the same type but with subtle composition differences are consumed and how performing a Temporal Dominance of Sensations (TDS) task modifies the way one eats. In addition, comparisons were made between performing a texture TDS (T-TDS) and a flavour TDS (F-TDS). Oral activity while eating biscuits with and without conducting a TDS task was recorded using a 3.dimensional motion capture system to monitor the evolution of jaw movements.
The results showed that oral activity evolved over the consumption time, differed depending on the texture of the sample and was affected to a small but significant extent when a TDS task was performed simultaneously (the differences averaged < 4 cycles, 1 s in duration, 0.1 cycles/s in frequency, and 1 mm in lateral displacement). The biscuit samples were affected equally. Almost no differences were found on comparing oral activity during the execution of the T-TDS and the F-TDS tasks.
Overall, the present results show differences in oral activity even for food products of the same category with subtle differences in composition. Performing TDS tasks (regardless of their modality) during sample consumption affected the total number, frequency and lateral amplitude of the chewing movements which should be taken into account for future research. However, these differences were small and affected both samples equally.The authors are grateful to the Spanish Ministry of the Economy and Competitiveness (AGL-2016-75403-R, Spain) and to the Regional Government of Valencia (Project Prometeo 2017/189, Spain) for financial support.Rizo, A.; Jimenez-Pérez, I.; Camacho-García, A.; Fiszman, S.; Pérez-Soriano, P.; Tarrega, A. (2019). Impact of texture TDS and flavour TDS tasks and of chocolate-chip biscuit characteristics on oral processing features. Food Quality and Preference. 76:109-117. https://doi.org/10.1016/j.foodqual.2019.04.005S1091177
Numerical resolution of Emden's equation using Adomian polynomials
Purpose: In this paper the authors aim to show the advantages of using the decomposition method introduced by Adomian to solve Emden's equation, a classical non‐linear equation that appears in the study of the thermal behaviour of a spherical cloud and of the gravitational potential of a polytropic fluid at hydrostatic equilibrium. Design/methodology/approach: In their work, the authors first review Emden's equation and its possible solutions using the Frobenius and power series methods; then, Adomian polynomials are introduced. Afterwards, Emden's equation is solved using Adomian's decomposition method and, finally, they conclude with a comparison of the solution given by Adomian's method with the solution obtained by the other methods, for certain cases where the exact solution is known. Findings: Solving Emden's equation for n in the interval [0, 5] is very interesting for several scientific applications, such as astronomy. However, the exact solution is known only for n=0, n=1 and n=5. The experiments show that Adomian's method achieves an approximate solution which overlaps with the exact solution when n=0, and that coincides with the Taylor expansion of the exact solutions for n=1 and n=5. As a result, the authors obtained quite satisfactory results from their proposal. Originality/value: The main classical methods for obtaining approximate solutions of Emden's equation have serious computational drawbacks. The authors make a new, efficient numerical implementation for solving this equation, constructing iteratively the Adomian polynomials, which leads to a solution of Emden's equation that extends the range of variation of parameter n compared to the solutions given by both the Frobenius and the power series methods.This work has been supported by the Ministerio de Ciencia e Innovación, project TIN2009-10581
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