RESUMEN
The spin-flip scattering mechanism in coupled self-assembled quantum dots made with InAs/GaAs with the use of realistic material parameters is theoretically and numerically investigated. The electron wave functions within the coupled system have been calculated by the 8-band strain dependent [Formula: see text] theory. The phonon coupling to electrons is described by deformation potential and piezoelectric acoustic phonons. First order perturbation theory has been employed to evaluate the spin relaxation rates and spin-flip time T1. The numerical results show that parameters like the interdot distance and the applied static magnetic field are of crucial importance in spin-flip mechanism. The spin relaxation time has been also studied by varying the lattice temperature and by showing the differences between the quantum computing operation temperature ([Formula: see text] K) and large temperatures.
RESUMEN
AIM: The purpose of our study was to investigate the differences in the finswimmers' physiological characteristics, as far as gender, the swimming style and the different swimming distance are concerned. METHODS: 52 finswimmers participated in our study (Age: 17.4⯱â¯2.1yrs, BMI: 21.8⯱â¯2.3, body fat: 12.2⯱â¯4.7%) and were allocated into groups [Gender: Female vs. Male, swimming style: Bifin vs. Surface, and swimming distance: <200â¯m vs. ≥200â¯m]. Anthropometric characteristics, handgrip, estimated strength of inspiratory muscles (PImax) and pulmonary function parameters (FEV1, FVC and PEF) were measured. The Independent T-test was used for statistical comparisons between groups. Multivariate analyses were performed via binary logistic regression. RESULTS: The results showed differences between groups in gender in PEF (pâ¯<â¯0.05), PImax (pâ¯<â¯0.05) and handgrip (pâ¯<â¯0.001) in swimming style in handgrip (pâ¯<â¯0.05), FEV1 (pâ¯<â¯0.05) and FVC (pâ¯<â¯0.05) and in swimming distance (pâ¯<â¯0.05) in hours/day spent at the gym (pâ¯<â¯0.05) and FVC (pâ¯<â¯0.05). In multivariate analyses handgrip remained an independent predictor of style (OR: 1.154; 95%CI: 1.022-1.303, pâ¯=â¯.021), and hours/day spent at the gym was retained as an independent predictor of distance (OR: 131.607; 95%CI: 3.655-4739.441, pâ¯=â¯.008). CONCLUSION: The data from the present study reveal that handgrip was associated with style, and hours per day spent at the gym were associated with distance.
Asunto(s)
Respiración , Natación/fisiología , Adolescente , Atletas , Femenino , Humanos , Modelos Logísticos , Masculino , Análisis Multivariante , Fuerza Muscular , Músculos Respiratorios/fisiología , Caracteres Sexuales , Espirometría , Factores de TiempoRESUMEN
Detailed realistic calculations of the spin-flip time (T 1) for an electron in a self-assembled quantum dot (SAQD) due to emission of an acoustic phonon, using only bulk properties with no fitting parameters, are presented. Ellipsoidal lens shaped [Formula: see text] [Formula: see text]As quantum dots, with electronic states calculated using 8-band strain dependent [Formula: see text] theory, are considered. The phonons are treated as bulk acoustic phonons coupled to the electron by both deformation potential and piezoelectric interactions. The dependence of T 1 on the geometry of SAQD, on the applied external magnetic field and on the lattice temperature is highlighted. The theoretical results are close to the experimental measurements on the spin-flip times for a single electron in QD.
RESUMEN
BACKGROUND: This study investigated local perceptions of changes stemming from a long-standing Group Interpersonal Psychotherapy (IPT-G) program for the treatment of depression in rural Uganda. The study was conducted in a low-income, severely HIV/AIDS-affected area where in 2001 the prevalence of depression was estimated at 21% among adults. METHOD: Data were collected using free-listing and key informant qualitative interviews. A convenience sample of 60 free-list respondents was selected from among IPT-G participants, their families, and other community members from 10 Ugandan villages. Twenty-two key informants and six IPT-G facilitators were also interviewed. RESULTS: Content analysis yielded five primary categories of change in the community related to the IPT-G program: (1) improved school attendance for children; (2) improved productivity; (3) improved sanitation in communities; (4) greater cohesion among community members; and (5) reduced conflict in families. Community members and IPT-G facilitators suggested that as depression remitted, IPT-G participants became more hopeful, motivated and productive. CONCLUSION: Results suggest that providing treatment for depression in communities with high depression prevalence rates may lead to positive changes in a range of non-mental health outcomes.
RESUMEN
An external magnetic field has been applied in laterally coupled quantum dots (QDs) and we have studied the QD properties related to charge decoherence. The significance of the applied magnetic field to the suppression of electron-phonon relaxation and dephasing rates has been explored. The coupled QDs have been studied by varying the magnetic field and the interdot distance as well as other system parameters. Our numerical results show that the electron scattering rates are strongly dependent on the applied external magnetic field and the details of the double QD configuration.