Transport in random quantum dot superlattices

We present a novel model to calculate single-electron states in random quantum dot superlattices made of wide-gap semiconductors. The source of disorder comes from the random arrangement of the quantum dots (configurational disorder) as well as spatial inhomogeneities of their shape (morphological disorder). Both types of disorder break translational symmetry and prevent the formation of minibands, as occurs in regimented arrays of quantum dots. The model correctly describes channel mixing and broadening of allowed energy bands due to elastic scattering by disorder

Professional Quality of Life and Emergency Department Nurses\u27 Communication Patterns

The purpose of this mixed methods embedded design study was to examine relationships between compassion satisfaction, burnout, compassion fatigue/secondary trauma, and perceived levels of communication difficulty in emergency room nurses employed at a health care system. Quantitative data was collected from a purposive sample of 43 emergency room nurses using the Professional Quality of Life Scale (ProQOL), the Silencing Response Scale, and a demographic form. The study\u27s embedded qualitative component was participants\u27 experiences with traumatic cases in the emergency room. Qualitative data was collected via telephone interview with 10 emergency room nurses obtained from a subset of the original sample and snowball sampling. The majority of participants reported low levels of compassion satisfaction on the ProQOL subscale (M = 38.63, SD 9.47), low levels of burnout and compassion fatigue/secondary trauma (M=21.4, SD 6.3 and M= 21.1, SD 5.2, respectively). Participants who worked in an urgent care setting scored highest (M= 44.3, SD 4.3) in perceived professional satisfaction in their ability as caregivers. The Silencing Response instrument yielded a mean score of 59.3, indicative of a moderate risk of communication difficulties for the entire sample. A correlation matrix indicated significant positive relationships between subscales of compassion satisfaction, burnout, compassion fatigue/secondary trauma, and the Silencing scale. Multiple regressions were conducted to explore the accuracy of the independent variables of compassion satisfaction, resource availability, burnout, compassion fatigue/secondary trauma, and years of experience as predictors of silencing scores. Partial regression coefficients on three separate models indicate compassion satisfaction, burnout, and compassion fatigue/secondary trauma significantly contribute to the models of predicting silencing response. Telephone interviews themes included pediatric traumas, discomfort, maintaining emotional control, obstructed communication, and deflection. The related themes potential support systems and available resources also potentially addressed decreased professional quality of life in emergency department nurses. This study contributes to the understanding of the relationship between professional quality of life and communication. The identification of relationships between the subscale items in concert with the participant interviews helped justify how coping strategies are implemented and is a first step in addressing deficiencies in communication

Electron states in a one-dimensional random binary alloy

We present a model for alloys of compound semiconductors by introducing a one-dimensional binary random system where impurities are placed in one sublattice while host atoms lie on the other sublattice. The source of disorder is the stochastic fluctuation of the impurity energy from site to site. Although the system is one-dimensional and random, we demonstrate analytical and numerically the existence of extended states in the neighborhood of a given resonant energy, which match that of the host atoms.Comment: 11 pages, REVTeX, 3 PostScript figure

Vector Meson Dominance, Axial Anomaly and the Thermal behavior of gρωπ(T)g_{\rho \omega \pi}(T)

By using a thermal Finite Energy QCD Sum Rule, we are able to establish the temperature dependence of the $g_{\omega \rho \pi}(T)$ strong coupling. It turns out that this coupling decreases as a function of temperature, vanishing at the critical temperature. This corresponds to a possible deconfining phenomenological signal. This result, together with the Vector Meson Dominance (VMD) expression for the amplitude $\pi ^{0} \to \gamma \gamma$, allows us to establish that this amplitude also vanishes at the critical temperature, in agreement with previous independent analysis. This results supports, once again, the validity of VMD at finite temperature. Several posssible scenarios are discussed. However, if VMD would not hold at finite temperature, then we will not be able to find a prediction for the thermal behavior of the $\pi ^{0} \to \gamma \gamma$ amplitude.Comment: Talk given at the QCD Euroconference, Montpellier July 2000 5 page

Relación entre la estructura en estado recocido del acero grado construcción y las propiedades mecánicas después de un tratamiento térmico final

En esta investigación se analizó la influencia de diferentes estructuras obtenidas en el proceso de recocido para la vida útil de los elementos finales (baleros). Se observó, con base en los resultados, que existe una estrecha relación entre las estructuras (tamaño de carburos) en estado recocido y las propiedades mecánicas de elementos finales después del temple y revenido

Innovation systems and regional resilience: a network analysis

European regions face several social and economic challenges. To overcome these challenges, each region needs to identify priority domains that promote innovation dynamics and represent competitive advantages for development and regional resilience. The innovative dynamics of a region largely depends on existing actors and their connectivity, so that the resilience of a given innovation system can be analyzed through the study of innovation networks. This article studies the case of Algarve, a peripheral region in the south of Portugal, through the use of Social Network Analysis. The results facilitate the identification of thematic groups of priorities for smart specialization and potentialities for the system improvement and suggest that the public policies must make efforts to stimulate the cooperation for the innovation, avoiding an excessive concentration of resources and the prominence of specific actors.Las regiones europeas presentan diversos retos sociales y económicos. Para superar estos desafíos es necesario que cada región identifique dominios prioritarios sobre los que concretar las dinámicas de innovación y sus ventajas competitivas, en pos del desarrollo y la resiliencia regional. Las dinámicas innovadoras de una región dependen de los actores existentes y de su conectividad, por lo que la resiliencia de un determinado sistema de innovación puede ser analizada a través del estudio de las redes de innovación. Este artículo estudia el caso de Algarve, una región periférica en el sur de Portugal, por medio del Análisis de Redes Sociales. Los resultados identifican grupos temáticos de prioridades para la especialización inteligente y potencialidades para la mejora del sistema. Sugieren, además, que las políticas públicas deben hacer esfuerzos para estimular la cooperación para la innovación, evitando la concentración excesiva de recursos y el protagonismo de actores específicosinfo:eu-repo/semantics/publishedVersio

Uso de galgas extensiométricas para obtener la fuerza de apriete entornillo autorroscante

Se describe cómo a través de la instrumentación de galgas extensiométricas en tornillos autorroscantes, se logra determinar la tensión generada en el tornillo al momento de aplicar en éste el par torsional. Esto se lleva acabo a través de pruebas de laboratorio, en las cuales se utilizaron tres tipos de acero en la placa en la que el tornillo autorroscante generó su cuerda, acero SAE 1018, SAE 1045 y SAE 1060.Al realizar cada prueba se obtiene la gráfica partorsional-ángulo y tensión-par torsional, las cuales muestran el comportamiento mecánico del ensamble en función de cada tipo de acero.Al desarrollar las pruebas y obtener las gráficas,es posible determinar ventajas y desventajas al utilizar galgas extensiométricas en tornillos autorroscantes, se obtiene la tensión en el tornillo y se determinan las variables del ensamble que más afectan la fuerza de tensiónen éste. Con todo esto se logra proveer la fuerza de apriete necesaria para el óptimo desempeño del ensamble, especialmente en uniones críticas