10,655 research outputs found
Contenido polínico de algunas plantas entomófilas ornamentales en la atmósfera de Salamanca
XV lnternational A.P.L.E. Symposium of Palynolog
Promotion of Healthy Physical Activity in School Recreation
Los autores desean mostrar su agradecimiento al profesorado de Educación Física de los centros participantes por su colaboración, a los equipos directivos de dichos centros por su apoyo y a las familias de los alumnos por autorizar la realización de la investigaciónEl objetivo de este trabajo fue investigar qué medidas se podrían tomar para aumentar los niveles generales de actividad física del alumnado de sexto de Educación Primaria durante los periodos de recreo escolar. Se implementó un programa específico desde el currículum de la asignatura de Educación Física y, después de haber finalizado la aplicación del citado programa, se comprobó los niveles de actividad física. También se realizó una observación pasados treinta días de su finalización, con el fin de comprobar en qué medida se modifican los hábitos de actividad física. El instrumento de recogida de datos fue el podómetro, que los participantes utilizaron durante los periodos de recreo escolar. El análisis de los resultados permite afirmar que la aplicación del programa específico objeto de estudio incide positivamente sobre el incremento del volumen de actividad física que realiza el alumnado en su tiempo libre y que, pasados treinta días desde su aplicación, el alumnado mantiene parte de incremento adquirido, modificando su hábito de actividad durante el recreo escolarThe objective of this work was to investigate what measures could be taken to increase the general levels of physical activity of students in sixth grade of Primary Education during the school breaks. A specific program was implemented from the curriculum of the subject of Physical Education and, after completing its application, physical activity levels were analyzed. In addition, an observation was conducted thirty days after its completion, in order to verify to what extent the habits of physical activity are modified. The instrument of data collection was the pedometer, which the participants used during the periods of school break. The analysis of the results allows affirming that the application of the specific program object of study affects positively on the increase of the volume of physical activity that the students do in their free time and that, after thirty days from its application, the students keep part of this increase acquired, which means a change in their activity habit during school break
Estudio aeropalinológico de la familia Oleaceae en la atmósfera de Salamanca (1995-2003)
XV lnternational A.P.L.E. Symposium of Palynolog
High temperature behavior of Sr-doped layered cobaltites Y(Ba1-xSrx)Co2O5.5: phase stability and structural properties
In this article we present a neutron diffraction in-situ study of the thermal
evolution and high-temperature structure of layered cobaltites Y(Ba, Sr)Co2
O5+{\delta}. Neutron thermodiffractograms and magnetic susceptibility
measurements are reported in the temperature range 20 K <= T <= 570 K, as well
as high resolution neutron diffraction experiments at selected temperatures.
Starting from the as-synthesized samples with {\delta} ~ 0.5, we show that the
room temperature phases remain stable up to 550 K, where they start loosing
oxygen and transform to a vacancy-disordered "112" structure with tetragonal
symmetry. Our results also show how the so-called "122" structure can be
stabilized at high temperature (around 450 K) in a sample in which the addition
of Sr at the Ba site had suppressed its formation. In addition, we present the
structural and magnetic properties of the resulting samples with a new oxygen
content {\delta} ~ 0.25 in the temperature range 20 K <= T <= 300 K
Robust symmetric multiplication for programmable analog VLSI array processing
This paper presents an electrically programmable analog multiplier. The circuit performs the multiplication between an input variable and an electrically selectable scaling factor. The multiplier is divided in several blocks: a linearized transconductor, binary weighted current mirrors and a differential to single-ended current adder. This paper shows the advantages introduced using a linearized OTA-based multiplier. The circuit presented renders higher linearity and symmetry in the output current than a previously reported single-transistor multiplier. Its inclusion in an array processor based on CNN allows for a more accurate implementation of the processing model and a more robust weight distribution scheme than those found in previous designs.Office of Naval Research (USA) N-00014- 02-1-0884Ministerio de Ciencia y Tecnología TIC2003-09817-C02-0
Flux-cutting and flux-transport effects in type-II superconductor slabs in a parallel rotating magnetic field
The magnetic response of irreversible type-II superconductor slabs subjected
to in-plane rotating magnetic field is investigated by applying the circular,
elliptic, extended-elliptic, and rectangular flux-line-cutting critical-state
models. Specifically, the models have been applied to explain experiments on a
PbBi rotating disk in a fixed magnetic field , parallel to the flat
surfaces. Here, we have exploited the equivalency of the experimental situation
with that of a fixed disk under the action of a parallel magnetic field,
rotating in the opposite sense. The effect of both the magnitude of the
applied magnetic field and its angle of rotation upon the
magnetization of the superconductor sample is analyzed. When is smaller
than the penetration field , the magnetization components, parallel and
perpendicular to , oscillate with increasing the rotation angle. On
the other hand, if the magnitude of the applied field, , is larger than
, both magnetization components become constant functions of at
large rotation angles. The evolution of the magnetic induction profiles inside
the superconductor is also studied.Comment: 12 pages, 29 figure
Relevance of Social, Economic, and Environmental Impacts on Residents’ Satisfaction with the Public Administration of Tourism
Those in charge of tourism destinations face the need to create tourism development models compatible with the essence of the localities that they manage. These models have to be sustainable, both environmentally and socially, and also must become drivers of the local economy. However, tourists also generate negative impacts in the locality which, when they are perceived by the residents, can give rise to a rejection of visitors. Hence, improving the tourism management is necessary. This is why to know the residents’ perceptions about the impacts of tourism is essential. Moreover, measuring the impact effects on their satisfaction with the public administration of the destination can be of great usefulness. This study falls into this research line, as it proposes a model to measure these impacts and their effect on satisfaction. To do so, an empirical study is performed among residents
in the city of Seville (southern Spain, one of the most visited destinations in the world), based on subjective economic, social, and environmental indicators. The results show that the citizens value three types of impacts, the social impact coming after the economic impact as to its influence on their satisfaction with the administration. Based on this, we postulate that the efforts made to attract events to the city, or to improve connections to access a broader market, must be approached as public procurements in which selection criteria that are compatible with the destination’s positioning and strategy prevail. Social and environmental criteria should be considered among these criteria
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