326 research outputs found
A city scale 3D geological model to support ground source heat recovery and storage
The Cardiff Urban Geo Observatory was established to characterise, monitor and model groundwater and heat flow in a shallow urban aquifer. Mapping showed that shallow ground groundwater temperatures exceeded 150C, due to effects of the subsurface urban heat island (Farr et al, 2017).
A 3D model of the superficial deposits was created to better understand the
aquifer dimensions and as a framework for a hydrogeological heat flow model
Towards coherent optical control of a single hole spin: rabi rotation of a trion conditional on the spin state of the hole
A hole spin is a potential solid-state q-bit, that may be more robust against nuclear spin induced dephasing than an electron spin. Here we propose and demonstrate the sequential preparation, control and detection of a single hole spin trapped on a self-assembled InGaAs/GaAs quantum dot. The dot is embedded in a photodiode structure under an applied electric field. Fast, triggered, initialization of a hole spin is achieved by creating a spin-polarized electron-hole pair with a picosecond laser pulse, and in an applied electric field, waiting for the electron to tunnel leaving a spin-polarized hole. Detection of the hole spin with picoseconds time resolution is achieved using a second picosecond laser pulse to probe the positive trion transition, where a trion is created conditional on the hole spin being detected as a change in photocurrent. Finally, using this setup we observe a Rabi rotation of the hole-trion transition that is conditional on the hole spin, which for a pulse area of 2 pi can be used to impart a phase shift of pi between the hole spin states, a non-general manipulation of the hole spin. (C) 2009 Elsevier Ltd. All rights reserved
Superconducting fluctuations and the Nernst effect: A diagrammatic approach
We calculate the contribution of superconducting fluctuations above the
critical temperature to the transverse thermoelectric response
, the quantity central to the analysis of the Nernst effect. The
calculation is carried out within the microscopic picture of BCS, and to linear
order in magnetic field. We find that as , the dominant contribution
to arises from the Aslamazov-Larkin diagrams, and is equal to the
result previously obtained from a stochastic time-dependent Ginzburg-Landau
equation [Ussishkin, Sondhi, and Huse, arXiv:cond-mat/0204484]. We present an
argument which establishes this correspondence for the heat current. Other
microscopic contributions, which generalize the Maki-Thompson and density of
states terms for the conductivity, are less divergent as .Comment: 11 pages, 5 figure
Understanding Galaxy Formation and Evolution
The old dream of integrating into one the study of micro and macrocosmos is
now a reality. Cosmology, astrophysics, and particle physics intersect in a
scenario (but still not a theory) of cosmic structure formation and evolution
called Lambda Cold Dark Matter (LCDM) model. This scenario emerged mainly to
explain the origin of galaxies. In these lecture notes, I first present a
review of the main galaxy properties, highlighting the questions that any
theory of galaxy formation should explain. Then, the cosmological framework and
the main aspects of primordial perturbation generation and evolution are
pedagogically detached. Next, I focus on the ``dark side'' of galaxy formation,
presenting a review on LCDM halo assembling and properties, and on the main
candidates for non-baryonic dark matter. It is shown how the nature of
elemental particles can influence on the features of galaxies and their
systems. Finally, the complex processes of baryon dissipation inside the
non-linearly evolving CDM halos, formation of disks and spheroids, and
transformation of gas into stars are briefly described, remarking on the
possibility of a few driving factors and parameters able to explain the main
body of galaxy properties. A summary and a discussion of some of the issues and
open problems of the LCDM paradigm are given in the final part of these notes.Comment: 50 pages, 10 low-resolution figures (for normal-resolution, DOWNLOAD
THE PAPER (PDF, 1.9 Mb) FROM http://www.astroscu.unam.mx/~avila/avila.pdf).
Lectures given at the IV Mexican School of Astrophysics, July 18-25, 2005
(submitted to the Editors on March 15, 2006
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
Measurement of the Mass Splittings between the States
We present new measurements of photon energies and branching fractions for
the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the
chi_b states are determined from the measured radiative photon energies. The
ratio of mass splittings between the chi_b substates,
r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information
on the nature of the bbbar confining potential. We find
r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world
average, but more consistent with the theoretical expectation that r(1P)<r(2P);
i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than
for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Impact of Chlamydia trachomatis in the reproductive setting: British Fertility Society Guidelines for practice
Chlamydia trachomatis infection of the genital tract is the most common sexually transmitted infection and has a world-wide distribution. The consequences of infection have an adverse effect on the reproductive health of women and are a common cause of infertility. Recent evidence also suggests an adverse effect on male reproduction. There is a need to standardise the approach in managing the impact of C. trachomatis infection on reproductive health. We have surveyed current UK practice towards screening and management of Chlamydia infections in the fertility setting. We found that at least 90% of clinicians surveyed offered screening. The literature on this topic was examined and revealed a paucity of solid evidence for estimating the risks of long-term reproductive sequelae following lower genital tract infection with C. trachomatis. The mechanism for the damage that occurs after Chlamydial infections is uncertain. However, instrumentation of the uterus in women with C. trachomatis infection is associated with a high risk of pelvic inflammatory disease, which can be prevented by appropriate antibiotic treatment and may prevent infected women from being at increased risk of the adverse sequelae, such as ectopic pregnancy and tubal factor infertility. Recommendations for practice have been proposed and the need for further studies is identified
Soccer and homosexuality: the conflicts that lie within the affective game of the coach-adolescent athlete relationship
Discussions regarding homosexuality within a sports context are mediated by emotional nuances, especially in the world of soccer, where practitioners are required to have attributes such as strength, masculinity and aggressiveness. As a consequence, this work aimed to analyze the symbolic representation of homosexual relationships between
adolescent soccer players and their coaches; and, furthermore, to understand the intention behind homoerotic relationships that are established between members of the management team and its players. In this study, researchers used the life history methodology, with participation from three adolescent athletes, ages 14, 15 and 16, and three former athletes, ages 26, 28 and 45, who we called speakers. Based on the collection and analysis of research participants’ testimonies, homosexual relations were found to have occurred between athletes and coaches, or between athletes and other members of the management team, as a part of a “social contract” that is exclusively linked to their professional objectives. These relationships appear to be purely objective; authentic affective links are absent, due apparently to the transient nature of the athletes in these groups. Too, this context is usually marked by the athlete’s physical and emotional vulnerability, and the agreements he makes within this context are accompanied with moral dilemmas, because such adolescents idealize the coach as a paternal archetype.“Futebol e homossexualidade: Os conflitos que se encontram dentro do jogo afetivo da relação treinador-atleta
adolescente.” As discussões a respeito da homossexualidade no contexto esportivo são mediadas por nuanças emocionais,
especialmente no mundo do futebol que exige de seus praticantes atributos de força, virilidade e agressividade. Por este
motivo este trabalho teve como objetivos diagnosticar existência de relações homossexuais entre atletas adolescentes da
modalidade de futebol e seus técnicos e sua representação simbólica e ainda, compreender a intencionalidade das relações
homoafetivas que se estabelecem entre componentes da equipe diretiva e os jogadores. Esta pesquisa é de natureza qualitativa
e a técnica adotada foi a “história de vida” e a participação de três atletas adolescentes em atividade, com idade de
14, 15 e 16 anos e três ex-atletas profissionais, com idades 26, 28 e 45 anos serviram de base metodológica. A partir da
análise e tratamento dos depoimentos verificou-se que ocorreram relações homossexuais nas categorias de base envolvendo
técnico e atleta, ou com outros membros da equipe diretiva, como parte dos contratos sociais, ligados exclusivamente a
objetivos profissionais. Estas relações parecem ser puramente objetais, não parecendo existir vínculos afetivos duradouros,
aparentemente, devido à natureza transitória de atletas nesses grupos. Também, nesses ambientes, muitas vezes marcados
pela vulnerabilidade física e emocional dos atletas, os acertos para as relações homossexuais são permeadas por dilemas
morais, tendo em vista que os atletas adolescentes idealizam o treinador como o arquétipo paterno ideal.“El fútbol y la homosexualidad: Los conflictos que se encuentran dentro del juego afectivo de la relación
atleta-entrenador de los adolescentes.” Las discusiones sobre la homosexualidad en contexto deportivo están mediadas por
matices emocionales, sobre todo en el mundo del fútbol que exige a sus jugadores atributos como la fuerza, la virilidad y los jugadores. En este estudio, los investigadores utilizaron la metodología de la historia de vida, con la participación de
tres atletas adolescentes, con 14, 15 y 16 años, y tres ex atletas con 26, 28 y 45 años, que llamamos ‘oradores’. Basado
en la recogida y análisis de testimonios de participantes en la investigación, se encontró que las relaciones homosexuales
que se han producido entre los atletas y entrenadores, o entre atletas y otros miembros del equipo de gestión, son como
parte de un “contrato social” que está vinculado exclusivamente a sus objetivos profesionales. Estas relaciones parecen
ser solamente como un objeto; porque a veces no hay vínculos afectivos auténticos, debido aparentemente a la naturaleza
transitoria de los atletas en estos grupos. Demasiado, este contexto es generalmente marcado por la vulnerabilidad física
y emocional del deportista, y los acuerdos que hace dentro de este contexto se acompañan con dilemas morales, debido
a que tales adolescentes idealizan el entrenador como un arquetipo paterno.
la agresividad. Por lo tanto, este estudio tuvo como objetivo diagnosticar la existencia de relaciones homosexuales entre
adolescentes atletas de fútbol y sus entrenadores y la representación simbólica de estas relaciones. También comprender
la intencionalidad de las relaciones homoafetivas que se intercambian entre algunos componentes del equipo directivo y(undefined
Formación docente para la implementación de la plataforma virtual Moodle como recurso didáctico en educación básica secundaria
1 recurso en línea (288 páginas) : ilustraciones color, tablas.Este estudio describe una experiencia llevada a cabo en entornos virtuales de aprendizaje Moodle, donde se planteó la utilización de la Educación Virtual como recurso didáctico educativo. A partir de un proceso de formación docente para la implementación de la plataforma virtual Moodle como recurso didáctico de enseñanza, se analizó si se presentaron cambios significativos en las competencias digitales: Pedagógica, tecnológica, comunicativa y de gestión, y a partir de ello se mejoró el desempeño pedagógico de los educadores; de igual forma se indago sobre la posibilidad de que las plataformas virtuales como Moodle puedan convertirse en una alternativa viable que pueda dar respuesta a los nuevos retos educativos relacionados con los ambientes virtuales de aprendizaje para dinamizar el proceso educativo. Como objetivo general del estudio se planteó Identificar las competencias digitales que poseen los docentes para el uso y administración de la plataforma Moodle, en el nivel de educación básica secundaria y media de la Institución Educativa Técnica de Monguí, para implementar un programa de formación encaminado a fortalecer dichas competencias. La metodología empleada en el estudio fue de tipo mixto, porque involucra aspectos cuantitativos como la medición de las variable competencias digitales desarrolladas por los docentes para el empleo de la plataforma virtual Moodle, desde el paradigma cualitativo se tuvieron en cuenta las opiniones y conceptos de los sujetos participantes en el estudio; de los resultados obtenidos se encontró que los programas de formación docente para el uso didáctico de las TIC en entornos de aprendizaje virtual como la plataforma Moodle, cuando son orientados con un modelo pedagógico activo diferente al catedrático, permiten que los educadores apropien el uso de estas tecnologías y sean gestores de proyectos que dinamizan el proceso enseñanza – aprendizaje, al brindar al estudiante la posibilidad de ser un agente participativo y por su puesto al educador ser guía y orientador en el proceso educativo.This study describes an experience carried out in Moodle virtual learning environments, where the use of Virtual Education as an educational didactic resource was proposed. From a process of teacher training for the implementation of the Moodle virtual platform as a didactic teaching resource, it was analyzed if there were significant changes in the digital competences: Pedagogical, technological, communicative and management, and from this the pedagogical performance of educators; In the same way, I inquired about the possibility that virtual platforms such as Moodle could become a viable alternative that could respond to new educational challenges related to virtual learning environments to boost the educational process. The general objective of the study was to identify the digital competences that teachers possess for the use and administration of the Moodle platform, at the level of secondary and secondary education of the Technical Educational Institution of Monguí, to implement a training program aimed at strengthen these competences The methodology used in the study was of mixed type, because it involved quantitative aspects such as the measurement of the variable digital competences developed by teachers for the use of the Moodle virtual platform, from the qualitative paradigm the opinions and concepts of the subjects participating in the study; From the results obtained it was found that the teacher training programs for the didactic use of ICT in virtual learning environments such as the Moodle platform, when they are oriented with an active pedagogical model different from the professor, allow educators to appropriate the use of these technologies and managers of projects that dynamize the teaching - learning process, giving the student the possibility of being a participative agent and of course the educator being a guide and guidance in the educational process.Bibliografía y webgrafía: páginas 196-205MaestríaMagíster en TIC Aplicadas a las Ciencias de la Educació
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