Search results for " spectrum"
showing 10 items of 1439 documents
Mössbauer Spectroscopic Evidence of Angle-Dependent Intersystem Crossing in LiNbO3:Fe3+
1986
M\"ossbauer emission spectra of LiNb${\mathrm{O}}_{3}$:$^{57}\mathrm{Co}$ single crystals in magnetic fields up to 5 T at 4.2 K show initial populations of the $^{6}A_{1\mathrm{g}}$ Zeeman substates of ${\mathrm{Fe}}^{3+}$ which depend strongly on the angle between the crystallographic $c$ axis and the magnetic field. This is interpreted in terms of a crystal-field effect on excited states which influences the initial populations of the Zeeman sublevels of the $^{6}A_{1\mathrm{g}}$ ground term after the electron-capture decay of $^{57}\mathrm{Co}$. An intersystem crossing process due to orbit-lattice interaction can fairly well explain the angular dependence.
SPATIAL MULTIFRACTALITY OF ELECTRONIC STATES AND THE METAL-INSULATOR TRANSITION IN DISORDERED SYSTEMS
1993
For the investigation of the spatial behavior of electronic wave functions in disordered systems, we employ the Anderson model of localization. The eigenstates of the corresponding Hamiltonian are calculated numerically by means of the Lanczos algorithm and are analyzed with respect to their spatial multifractal properties. We find that the wave functions show spatial multifractality for all parameter cases not too far away from the metal-insulator transition (MIT) which separates localized from extended states in this model. Exactly at the MIT, multifractality is expected to exist on all length scales larger than the lattice spacing. It is found that the corresponding singularity spectrum…
Lower cortisol response in high-resilient caregivers of people with autism: the role of anger
2016
Caring for an offspring with an autism spectrum disorder (ASD) has been related to high stress levels and health disturbances. However, a protective effect against these negative health outcomes has been described in high-resilient caregivers. In this context, the main aim of the present study was to assess the association between resilient coping and cortisol response to acute stress in caregivers of people with ASD. Furthermore, the study aimed to explore the mediating role of anger in this association. We exposed 40 caregivers of people with ASD to an acute psychosocial stressor in the laboratory. Salivary cortisol samples were obtained before, during, and after the stressor. Resilient c…
ESTRÉS Y AFRONTAMIENTO EN FAMILIAS DE HIJOS CON TRASTORNO DE ESPECTRO AUTISTA
2016
Abstract.Research shows the relationship between having children with neurodevelopmental disorders and family stress. The Autism Spectrum Disorder or ASD has its own symptoms and a number of additional problems that give it a distinctive profile. These differences are reflected in the levels of stress shown by caregivers of children with the disorder. Coping is a reaction to behavioral and / or psychological stress, aimed at reducing the destructive stress attributes. Theories of stress and coping, as well as more specific models of family accommodation show how coping strategies have an important role in the outcome of adaptation. Consequently, depending on the type of coping strategies us…
ESTRATEGIAS Y ESTILOS DE AFRONTAMIENTO PARENTAL EN FAMILIAS CON NIÑOS CON TRASTORNO DE ESPECTRO AUTISTA (TEA) CON O SIN TRASTORNO POR DÉFICIT DE ATEN…
2015
La crianza de un hijo con Trastorno del Espectro Autista (TEA) ocasiona un fuerte impacto sobre la dinámica familiar. Cuando este trastorno se presenta con otro comórbido, como el Trastorno por Déficit de Atención con Hiperactividad (TDAH), las repercusiones sobre el bienestar psicológico de los padres pueden verse considerablemente aumentadas. Conocer qué estilos y estrategias de afrontamiento se emplean con mayor frecuencia podría contribuir a diseñar intervenciones con las familias, que pudieran repercutir positivamente en la manifestación de la sintomatología autista. El objetivo de este estudio consiste en profundizar en los estilos y estrategias de afrontamiento más frecuentes de esta…
Management of children with autism spectrum disorder in the dental setting
2013
Objectives: This article reviews the present literature on the issues encountered while coping with children with autistic spectrum disorder from the dental perspective. The autistic patient profile and external factors affecting the oral health status of this patient population are discussed upon the existing body of evidence. Material and Methods: The MEDLINE database was searched using the terms ‘Autistic Disorder’, ‘Behaviour Control/methods’, ‘Child’, ‘Dental care for disabled’, ‘Education’, ‘Oral Health’, and ‘Pediatric Dentistry’ to locate related articles published up to January 2013. Results: Most of the relevant studies indicate poor oral hygiene whereas they are inconclusive rega…
Segregation of copper oxide on calcium copper titanate surface induced by Graphene Oxide for Water splitting applications
2020
Abstract Photoelectrochemical cells (PEC) are promising devices for hydrogen production via sunlight energy. One of the important challenges in this area is to design photoactive electrodes able to absorb visible light. A good photoelectrochemical behavior depends on the presence of surface active sites to photogenerate current at the lower possible potential for water splitting. Recent investigations in this field are focusing on perovskite materials such as CaCu3Ti4O12 (CCTO) as visible light active electrode due its outstanding structure in which CCTO encloses in its structure a visible light absorbance component (CuO). The presence CuO on the material surface is mainly responsible for t…
Optical nonlinear correlation based on nonuniform subband decomposition
1999
We present a nonlinear correlation to improve the selectivity for optical pattern recognition. The approach is based on morphological correlation which involves a threshold decomposition concept. Hereby, we propose a subband decomposition in the Fourier domain to perform the threshold decomposition operation. We consider two frequency bands that give rise to two separate channels. We apply the morphological correlation to each channel using a localized threshold decomposition. Then, we define a two-channel morphological correlation. The final detection decision is made as a combination of both correlation outputs. The two-channel morphological correlation yields improved discrimination capa…
The Impact of the Mass Spectrum of Lenses in Quasar Microlensing Studies. Constraints on a Mixed Population of Primordial Black Holes and Stars
2020
We show that quasar microlensing magnification statistics induced by a population of point microlenses distributed according to a mass-spectrum can be very well approximated by that of a single-mass, "monochromatic", population. When the spatial resolution (physically defined by the source size) is small as compared with the Einstein radius, the mass of the monochromatic population matches the geometric mean of the mass-spectrum. Otherwise, the best-fit mass can be larger. Taking into account the degeneracy with the geometric mean, the interpretation of quasar microlensing observations under the hypothesis of a mixed population of primordial black holes and stars, makes the existence of a s…
ELDAR, a new method to identify AGN in multi-filter surveys: the ALHAMBRA test case
2017
We present ELDAR, a new method that exploits the potential of medium- and narrow-band filter surveys to securely identify active galactic nuclei (AGN) and determine their redshifts. Our methodology improves on traditional approaches by looking for AGN emission lines expected to be identified against the continuum, thanks to the width of the filters. To assess its performance, we apply ELDAR to the data of the ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey, which covered an effective area of 2.38 deg2 with 20 contiguous medium-band optical filters down to F814W ≃ 24.5. Using two different configurations of ELDAR in which we require the detection of at lea…