3,136 research outputs found
Eruption of magnetic flux ropes during flux emergence
Aims: We investigate the formation of flux ropes in a flux emergence region
and their rise into the outer atmosphere of the Sun.
Methods: We perform 3D numerical experiments solving the time-dependent and
resistive MHD equations.
Results: A sub-photospheric twisted flux tube rises from the solar interior
and expands into the corona. A flux rope is formed within the expanding field,
due to shearing and reconnection of field lines at low atmospheric heights. If
the tube emerges into a non-magnetized atmosphere, the flux rope rises, but
remains confined inside the expanding magnetized volume. On the contrary, if
the expanding tube is allowed to reconnect with a preexisting coronal field,
the flux rope experiences a full eruption with a rise profile which is in
qualitative agreement with erupting filaments and Coronal Mass Ejections
Nanowire and core-shell-structures on flexible Mo Foil for CdTe solar cell applications
CdTe films, nanowires, film-nanowire combinations and CdS-CdTe core-shell structures have been fabricated in a preliminary survey of growth methods that will generate structures for PV applications. Selectivity between film, nanowire and film plus nanowire growth was achieved by varying the pressure of N2 gas present during Au-catalysed VLS growth of CdTe, on either Mo or Si substrates. Metamorphic growth of CdTe nanowires on sputtered CdTe films, deposited on glass substrates, was demonstrated. Coating of CdTe nanowires with CBD CdS gave conformal coverage whereas coating with MOCVD (Cd,Zn)S yielded highly crystallographic dendritic growth on the wires
Quantum theory for the nanoscale propagation of light through stacked thin film layers
Stacked multi-layer films have a range of well-known applications as optical elements. The various types of theory commonly used to describe optical propagation through such structures rarely take account of the quantum nature of light, though phenomena such as Anderson localization can be proven to occur under suitable conditions. In recent and ongoing work based on quantum electrodynamics, it has been shown possible to rigorously reformulate, in photonic terms, the fundamental mechanisms that are involved in reflection and optical transmission through stacked nanolayers. Accounting for sum-over-pathway features in the quantum mechanical description, this theory treats the sequential interactions of photons with material boundaries in terms of individual scattering events. The study entertains an arbitrary number of reflections in systems comprising two or three internally reflective surfaces. Analytical results are secured, without recourse to FTDT (finite-difference time-domain) software or any other finite-element approximations. Quantum interference effects can be readily identified. The new results, which cast the optical characteristics of such structures in terms of simple, constituent-determined properties, are illustrated by model calculations
Quantum electrodynamics in modern optics and photonics: tutorial
One of the key frameworks for developing the theory of light–matter interactions in modern optics and photonics is quantum electrodynamics (QED). Contrasting with semiclassical theory, which depicts electromagnetic radiation as a classical wave, QED representations of quantized light fully embrace the concept of the photon. This tutorial review is a broad guide to cutting-edge applications of QED, providing an outline of its underlying foundation and an examination of its role in photon science. Alongside the full quantum methods, it is shown how significant distinctions can be drawn when compared to semiclassical approaches. Clear advantages in outcome arise in the predictive capacity and physical insights afforded by QED methods, which favors its adoption over other formulations of radiation–matter interaction
A randomized controlled trial of the impact of a teacher classroom management program on the classroom behavior of children with and without behavior problems
The Stellar Phase Density of the Local Universe and its Implications for Galaxy Evolution
This paper introduces the idea that the general mixing inequality obeyed by
evolving stellar phase densities may place useful constraints on the possible
history of the over-all galaxy population. We construct simple models for the
full stellar phase space distributions of galaxies' disk and spheroidal
components, and reproduce the well-known result that the maximum phase density
of an elliptical galaxy is too high to be produced collisionlessly from a disk
system, although we also show that the inclusion of a bulge component in the
disk removes this evolutionary impediment. In order to draw more general
conclusions about the evolution of the galaxy population, we use the Millennium
Galaxy Catalogue to construct a model of the entire phase density distribution
of stars in a representative sample of the local Universe. In such a composite
population, we show that the mixing inequality rules out some evolutionary
paths that are not prohibited by consideration of the maximum phase density
alone, and thus show that the massive ellipticals in this population could not
have formed purely from collisionless mergers of a low mass galaxy population
like that found in the local Universe. Although the violation of the mixing
inequality is in this case quite minor, and hence avoidable with a modest
amount of non-collisionless star formation in the merger process, it does
confirm the potential of this approach. The future measurement of stellar phase
densities at higher redshift will allow this potential to be fully exploited,
offering a new way to look at the possible pathways for galaxy evolution, and
to learn about the environment of star formation through the way that this
phase space becomes populated over time.Comment: 6 pages, 4 figures, accepted for publication in Astronomy &
Astrophysic
The Illustrated History of the Riverine Force: The Vietnam War, The Illustrated History of Carrier Operations: The Vietnam War, and The Illustrated History of the Marines: The Vietnam War
Koinonia
The ProfessionFaculty and Student Development Staff as Partners in Education, Barry Loy
Is it Okay to Struggle as Student Development Professionals?, Terry Williams
Conference SpotlightLeading Ladies: Transformative Biblical Images for Women\u27s Leadership, Jeanne Porter
Mi Abuelito, Tom Neven
Campus EventsQuestions Without Answers, JR Kerr
Book ReviewsLet Your Life Speak, reviewed by Dana Forbes
Mountains and Passes, reviewed by Jeff Doyle
FeaturesThe President\u27s Corner
Editor\u27s Diskhttps://pillars.taylor.edu/acsd_koinonia/1009/thumbnail.jp
Respeto y tolerancia, claves para la convivencia y la resolución de conflictos escolares
This research aimed to propose strategies based on the values of respect and tolerance to raise
awareness among students about the consequences of violent acts, awakening in them the interest
to improve school coexistence, to reach this achievement, different aspects were analyzed.
school coexistence that serve as tools in the development of the solution to the problem of
coexistence within the institution, likewise identified strategies to be developed in the classroom
and outside it, to allow those involved (managers, teachers , students and parents) reflect on their
violent acts, recognizing their responsibility in it, as well as act appropriately. It was based on
previous studies on the subject, theories about school coexistence and the resolution of conflicts
and developed a descriptive quantitative methodology, which led to the consultation by survey of
two key actors, students and teachers. The scenario was the educational institution BROOKS
HILL BILINGUAL SCHOOL of the Island of San Andres-Colombia. The results allowed to
conclude that the problems of coexistence and conflicts in the classroom are increasing and
present problems in their management by teachers and parents, likewise there is no institutional
monitoring that allows the integral approach. Teachers do not have the necessary training or
tools. The research is concluded with the recommendation of a series of strategies that must be
developed in the institution and in the classrooms.Esta investigación se planteó como objetivo proponer estrategias basadas en los valores de
respeto y tolerancia para concientizar a los estudiantes, sobre las consecuencias de los actos
violentos, despertando en ellos el interés por mejorar la convivencia escolar, para llegar a este
logro se analizaron distintos aspectos de la convivencia escolar que sirven como herramientas en
el desarrollo de la solución a la problemática de la convivencia dentro de la institución, así
mismo se identificaron estrategias a ser desarrolladas en el aula y fuera de ella, que permitan a
los involucrados (directivos, docentes, estudiantes y padres) reflexionar sobre sus actos
violentos, reconociendo su responsabilidad en la misma, así como actuar de forma adecuada. Se
fundamentó en estudios previos sobre el tema, teorías sobre la convivencia escolar y la
resolución de conflictos y desarrolló una metodología cuantitativa descriptiva, que llevó a la
consulta por encuesta de dos actores clave, los estudiantes y los docentes. El escenario fue la
Institución educativa BROOKS HILL BILINGUAL SCHOOL de la Isla de San Andrés
Colombia. Los resultados permitieron concluir que los problemas de convivencia y los conflictos
en el aula están en aumento y presentan problemas en su manejo por parte de docentes y padres,
así mismo no se hace un seguimiento institucional que permita el abordaje integral. Los docentes
no cuentan con la formación u herramientas necesarias. Se concluye la investigación con la
recomendación de una serie de estrategias que deben ser desarrolladas en la institución y las
aulas
- …