1,976 research outputs found
Designing and Piloting a Tool for the Measurement of the Use of Pronunciation Learning Strategies
What appears to be indispensable to drive the field forward and ensure that research findings will be comparable across studies and provide a sound basis for feasible pedagogic proposals is to draw up a classification of PLS and design on that basis a valid and reliable data collection tool which could be employed to measure the use of these strategies in different groups of learners, correlate it with individual and contextual variables, and appraise the effects of training programs. In accordance with this rationale, the present paper represents an attempt to propose a tentative categorization of pronunciation learning strategies, adopting as a point of reference the existing taxonomies of strategic devices (i.e. O'Malley and Chamot 1990; Oxford 1990) and the instructional options teachers have at their disposal when dealing with elements of this language subsystem (e.g. Kelly 2000; Goodwin 2001). It also introduces a research instrument designed on the basis of the classification that shares a number of characteristics with Oxford's (1990) Strategy Inventory for Language Learning but, in contrast to it, includes both Likert-scale and open-ended items. The findings of a pilot study which involved 80 English Department students demonstrate that although the tool requires considerable refinement, it provides a useful point of departure for future research into PLS
Scoping studies: towards a methodological framework
This paper focuses on scoping studies, an approach to reviewing the literature which to date has received little attention in the research methods literature. We distinguish between different types of scoping studies and indicate where these stand in relation to full systematic reviews. We outline a framework for conducting a scoping study based on our recent experiences of reviewing the literature on services for carers for people with mental health problems. Where appropriate, our approach to scoping the field is contrasted with the procedures followed in systematic reviews. We emphasize how including a consultation exercise in this sort of study may enhance the results, making them more useful to policy makers, practitioners and service users. Finally, we consider the advantages and limitations of the approach and suggest that a wider debate is called for about the role of the scoping study in relation to other types of literature reviews
Loss and decoherence due to stray infrared light in superconducting quantum circuits
We find that stray infrared light from the 4 K stage in a cryostat can cause
significant loss in superconducting resonators and qubits. For devices shielded
in only a metal box, we measured resonators with quality factors Q = 10^5 and
qubits with energy relaxation times T_1=120 ns, consistent with a stray
light-induced quasiparticle density of 170-230 \mu m^{-3}. By adding a second
black shield at the sample temperature, we found about an order of magnitude
improvement in performance and no sensitivity to the 4 K radiation. We also
tested various shielding methods, implying a lower limit of Q = 10^8 due to
stray light in the light-tight configuration.Comment: 4 pages, 4 figure
Electron affinity of Li: A state-selective measurement
We have investigated the threshold of photodetachment of Li^- leading to the
formation of the residual Li atom in the state. The excited residual
atom was selectively photoionized via an intermediate Rydberg state and the
resulting Li^+ ion was detected. A collinear laser-ion beam geometry enabled
both high resolution and sensitivity to be attained. We have demonstrated the
potential of this state selective photodetachment spectroscopic method by
improving the accuracy of Li electron affinity measurements an order of
magnitude. From a fit to the Wigner law in the threshold region, we obtained a
Li electron affinity of 0.618 049(20) eV.Comment: 5 pages,6 figures,22 reference
Mg(, )Na reaction study for spectroscopy of Na
The Mg(, )Na reaction was measured at the Holifield
Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to
better constrain spins and parities of energy levels in Na for the
astrophysically important F()Ne reaction rate
calculation. 31 MeV proton beams from the 25-MV tandem accelerator and enriched
Mg solid targets were used. Recoiling He particles from the
Mg(, )Na reaction were detected by a highly segmented
silicon detector array which measured the yields of He particles over a
range of angles simultaneously. A new level at 6661 5 keV was observed in
the present work. The extracted angular distributions for the first four levels
of Na and Distorted Wave Born Approximation (DWBA) calculations were
compared to verify and extract angular momentum transfer.Comment: 11 pages, 6 figures, proceedings of the 18th International Conference
on Accelerators and Beam Utilization (ICABU2014
Isobaric multiplet mass equation in the quartets
The observed mass excesses of analog nuclear states with the same mass number
and isospin can be used to test the isobaric multiplet mass equation
(IMME), which has, in most cases, been validated to a high degree of precision.
A recent measurement [Kankainen et al., Phys. Rev. C 93 041304(R) (2016)] of
the ground-state mass of Cl led to a substantial breakdown of the IMME
for the lowest quartet. The second-lowest
quartet is not complete, due to uncertainties associated with the identity of
the S member state. Using a fast Cl beam implanted into a plastic
scintillator and a high-purity Ge -ray detection array, rays
from the ClS sequence were measured. Shell-model
calculations using USDB and the recently-developed USDE interactions were
performed for comparison. Isospin mixing between the S isobaric analog
state (IAS) at 6279.0(6) keV and a nearby state at 6390.2(7) keV was observed.
The second state in S was observed at keV.
Isospin mixing in S does not by itself explain the IMME breakdown in the
lowest quartet, but it likely points to similar isospin mixing in the mirror
nucleus P, which would result in a perturbation of the P IAS
energy. USDB and USDE calculations both predict candidate P states
responsible for the mixing in the energy region slightly above
keV. The second quartet has been completed thanks to the identification of the
second S state, and the IMME is validated in this quartet
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