4,036 research outputs found
Learning to live with a new educational technology: an exploration of tertiary teachers’ experience in the Middle East
This thesis aims to tell the story of a group of teachers at one college involved in the iPad implementation. It considers the effect that the implementation had on their professional identities and how they coped with the experience. Underlying the study is a research-based exploratory background that highlights the importance of acknowledging teachers’ perceptions and experiences for the successful integration of a new learning technology into classrooms. The subject of this study is a group of teachers who were required to adopt a new technology to teach English to Foundation students at a university in the Middle East. The Apple iPad was to be the exclusive means of delivery: no books, stationery or writing equipment was to be allowed in the classrooms. The teachers were ‘constructive agents’ (Spivey, 2007, p. 3) who built their knowledge of teaching with the iPad out of interaction with their colleagues, the context and the culture of their reality. Their professional identities impacted on how they coped with the new challenges and at the same time, the new challenges impacted on their identities. Conducting a narrative thematic analysis allows justice to be done to the experiences the teachers referred to in the interviews, observations, reflections and email exchanges. The data revealed a rich lived experience and captured complex, detailed and evolving descriptions from the teachers (Braun, Clarke, Hayfield, & Terry, 2019). I became part of the narrative frame of their storytelling revealed by this narrative thematic analysis. The findings show that the teachers used a variety of strategies to respond to the sudden change, the negative surprises they encountered were turned into learning experiences and they drew on their professional identities and community for support. An interesting paradox is uncovered as it is revealed that positive outcomes can be achieved as a result of experiential learning, despite a perceived lack of appropriate planning, information and preparation
Spin entanglement, decoherence and Bohm's EPR paradox
We obtain criteria for entanglement and the EPR paradox
for spin-entangled particles and analyse the effects of decoherence caused
by absorption and state purity errors. For a two qubit photonic state,
entanglement can occur for all transmission efficiencies. In this case,
the state preparation purity must be above a threshold value. However,
Bohm’s spin EPR paradox can be achieved only above a critical level of
loss. We calculate a required efficiency of 58%, which appears achievable
with current quantum optical technologies. For a macroscopic number of
particles prepared in a correlated state, spin entanglement and the EPR
paradox can be demonstrated using our criteria for efficiencies η > 1/3
and η > 2/3 respectively. This indicates a surprising insensitivity to loss
decoherence, in a macroscopic system of ultra-cold atoms or photons
Uniform semiclassical approximation in quantum statistical mechanics
We present a simple method to deal with caustics in the semiclassical
approximation to the partition function of a one-dimensional quantum system.
The procedure, which makes use of complex trajectories, is applied to the
quartic double-well potential.Comment: 5 pages, 1 figure, Latex. Contribution to the Proceedings of the XXI
Brazilian National Meeting on Particles and Fields (Sao Lourenco, October
23-27, 2000
Experimental criteria for steering and the Einstein-Podolsky-Rosen paradox
We formally link the concept of steering (a concept created by Schrodinger
but only recently formalised by Wiseman, Jones and Doherty [Phys. Rev. Lett.
98, 140402 (2007)] and the criteria for demonstrations of
Einstein-Podolsky-Rosen (EPR) paradox introduced by Reid [Phys. Rev. A, 40, 913
(1989)]. We develop a general theory of experimental EPR-steering criteria,
derive a number of criteria applicable to discrete as well as
continuous-variables observables, and study their efficacy in detecting that
form of nonlocality in some classes of quantum states. We show that previous
versions of EPR-type criteria can be rederived within this formalism, thus
unifying these efforts from a modern quantum-information perspective and
clarifying their conceptual and formal origin. The theory follows in close
analogy with criteria for other forms of quantum nonlocality (Bell-nonlocality,
entanglement), and because it is a hybrid of those two, it may lead to insights
into the relationship between the different forms of nonlocality and the
criteria that are able to detect them.Comment: Changed title, updated references, minor corrections, added
journal-ref and DO
THE EXPERIMETAL INVESTIGATION OF EVAPORATOR’S CONDITION ON PERFORMANCE OF REFRIGERATION SYSTEMS
Due to the heat and mass transfer characteristics, the cooling and dehumidifying processes of evaporator are complex. In this sense, the present paper details the heat and mass transfer coefficients of moist air over surfaces for different cooling mode: dry, wet and partially wet. A modeling of the classical evaporator was reviewed by using finned surfaces wavy correlations for air-side. The mode of cooling was determined through a latent air–side convective heat transfer coefficient by correlating the experimental data with the model. In the literature have values of fouling factor for oil-bearing refrigerant and a fouling factor for air side coefficients for evaporator in operation for five years. The results have shown new values for these coefficients for evaporator in operation for eight years identifying a reduction of the nominal refrigeration capacity
- …