4,560 research outputs found
Factors influencing take-up of free school meals in primary- and secondary-school children in England.
OBJECTIVE: The present study sought to explore the factors that influence registration for free school meals and the subsequent take-up following registration in England. DESIGN: The research design consisted of two phases, a qualitative research phase followed by an intervention phase. Findings are presented from the qualitative research phase, which comprised interviews with head teachers, school administrators, parents and focus groups with pupils. SETTING: The study took place in four primary schools and four secondary schools in Leeds, UK. SUBJECTS: Participants included head teachers, school administrators, parents and pupils. RESULTS: Findings suggested that parents felt the registration process to be relatively straightforward although many secondary schools were not proactive in promoting free school meals. Quality and choice of food were regarded by both pupils and parents as significant in determining school meal choices, with stigma being less of an issue than originally anticipated. CONCLUSIONS: Schools should develop proactive approaches to promoting free school meals and attention should be given not only to the quality and availability of food, but also to the social, cultural and environmental aspects of dining. Processes to maintain pupils' anonymity should be considered to allay parents' fear of stigma
Interventions to increase free school meal take-up
Purpose: The purpose of this paper is to design and implement interventions to increase free school meal (FSM) uptake in pilot schools. This paper describes the interventions, reports on acceptability (as perceived by school working parties) and explores the process of implementing change. Design/methodology/approach: The research consisted of two phases, an exploratory phase followed by an intervention phase. Findings from the latter are presented. Ten pilot schools (five primary and five secondary) in Leeds, England were recruited. Each established a working party, examined current claiming processes and implemented individualised action plans. This paper draws on the final action plans and interviews/focus groups with working parties. Findings: Interventions to improve FSM claiming process, minimise discrimination and maximise awareness were designed. The majority were implemented successfully, the exception being amending anti-bullying policies. Creative ways of delivering interventions were demonstrated. The process of change was effective, critical factors being having individualised action plans that allowed flexibility in implementation, reflecting on current claiming processes, and setting up working parties. Practical implications: Ways of working with schools to increase FSM uptake and more generally improve nutritional policies are suggested. Amending claiming systems in schools is recommended as is greater pupil and parent involvement in nutrition policies. Originality/value: An estimated 300,000 UK children do not take FSMs they are entitled to ā with many schools unaware of the issue. This study worked with schools to discover how to address this issue and evaluated the perceived acceptability and feasibility of the approach
Polaron effective mass from Monte Carlo simulations
A new Monte Carlo algorithm for calculating polaron effective mass is
proposed. It is based on the path-integral representation of a partial
partition function with fixed total quasi-momentum. Phonon degrees of freedom
are integrated out analytically resulting in a single-electron system with
retarded self-interaction and open boundary conditions in imaginary time. The
effective mass is inversely proportional to the covariance of total energy
calculated on an electron trajectory and the square distance between ends of
the trajectory. The method has no limitations on values of model parameters and
on the size and dimensionality of the system although large statistics is
required for stable numerical results. The method is tested on the
one-dimensional Holstein model for which simulation results are presented.Comment: 4 pages + 1 figure, RevTeX. Accepted for publication as a Rapid
Communication in Phys.Rev.
Classical Rules in Quantum Games
We consider two aspects of quantum game theory: the extent to which the
quantum solution solves the original classical game, and to what extent the new
solution can be obtained in a classical model.Comment: The previous title, "Quantum games are no fun (yet)", was too
whimsical for Physical Review. This is a comment on most, but not all, papers
on quantum game theor
Hysteresis loops of Co-Pt perpendicular magnetic multilayers
We develop a phenomenological model to study magnetic hysteresis in two
samples designed as possible perpendicular recording media. A stochastic
cellular automata model captures cooperative behavior in the nucleation of
magnetic domains. We show how this simple model turns broad hysteresis loops
into loops with sharp drops like those observed in these samples, and explains
their unusual features. We also present, and experimentally verify, predictions
of this model, and suggest how insights from this model may apply more
generally.Comment: 4.5 pages, 5 figure
Effect of high temperature heat treatments on the quality factor of a large-grain superconducting radio-frequency niobium cavity
Large-grain Nb has become a viable alternative to fine-grain Nb for the
fabrication of superconducting radio-frequency cavities. In this contribution
we report the results from a heat treatment study of a large-grain 1.5 GHz
single-cell cavity made of "medium purity" Nb. The baseline surface preparation
prior to heat treatment consisted of standard buffered chemical polishing. The
heat treatment in the range 800 - 1400 C was done in a newly designed vacuum
induction furnace. Q0 values of the order of 2x1010 at 2.0 K and peak surface
magnetic field (Bp) of 90 mT were achieved reproducibly. A Q0-value of
(5+-1)1010 at 2.0 K and Bp = 90 mT was obtained after heat treatment at 1400 C.
This is the highest value ever reported at this temperature, frequency and
field. Samples heat treated with the cavity at 1400 C were analyzed by
secondary ion mass spectrometry, secondary electron microscopy, energy
dispersive X-ray, point contact tunneling and X-ray diffraction and revealed a
complex surface composition which includes titanium oxide, increased carbon and
nitrogen content but reduced hydrogen concentration compared to a non
heat-treated sample
Low-Temperature Permittivity of Insulating Perovskite Manganites
Measurements of the low-frequency (f<=100 kHz) permittivity and conductivity
at T<= 150 K are reported for La(1-x)Ca(x)MnO(3) (0<=x<=1) and
Ca(1-y)Sr(y)MnO(3) (0<=y<=0.75) having antiferromagnetic, insulating ground
states covering a broad range of Mn valencies from Mn(3+) to Mn(4+). Static
dielectric constants are determined from the low-T limiting behavior. With
increasing T, relaxation peaks associated with charge-carrier hopping are
observed in the real part of the permittivities and analyzed to determine
dopant binding energies. The data are consistent with a simple model of
hydrogenic impurity levels and imply effective masses m*/m_e~3 for the Mn(4+)
compounds. Particularly interesting is a large dielectric constant (~100)
associated with the C-type antiferromagnetic state near the composition
La(0.2)Ca(0.8)MnO(3).Comment: 6 pages, 8 figures, PRB in pres
Further studies of space-time clustering of Burkitt's lymphoma in Uganda.
All hospital-treated cases of Burkitt's lymphoma (BL), with onset of symptoms in the period 1963-68 and resident in the Lango and Acholi districts of Uganda, were identified. The average annual incidence of BL in the 6-year period was 1-87 X 10(-5), similar to that in the adjacent West Nile district. Contrary to findings in other areas of Uganda, there was no evidence of seasonal variation in the onset of cases, nor of space-time clustering, nor of a decline in the incidence of BL in the study period. An inverse relationship was noted between the median age at onset of BL and the incidence of the disease in different areas of Uganda, a finding consistent with intense malarial infection being a precipitating factor for BL. The variable observations with respect to space-time clustering of BL and seasonal variation in incidence in different areas remains unexplained, but it is suggested that a closer study of the patterns of malarial infection in these areas may help to account for the findings
Understanding fine magnetic particle systems through use of first-order reversal curve diagrams
First-order reversal curve (FORC) diagrams are constructed from a class of partial magnetic hysteresis loops known as first-order reversal curves and are used to understand magnetization processes in fine magnetic particle systems. A wide-ranging literature that is pertinent to interpretation of FORC diagrams has been published in the geophysical and solid-state physics literature over the past 15āyears and is summarized in this review. We discuss practicalities related to optimization of FORC measurements and important issues relating to the calculation, presentation, statistical significance, and interpretation of FORC diagrams. We also outline a framework for interpreting the magnetic behavior of magnetostatically noninteracting and interacting single domain, superparamagnetic, multidomain, single vortex, and pseudosingle domain particle systems. These types of magnetic behavior are illustrated mainly with geological examples relevant to paleomagnetism, rock magnetism, and environmental magnetism. These technical, experimental, and interpretational considerations are relevant to applications that range from improving particulate media for magnetic recording in materials science, to providing a foundation for understanding geomagnetic recording by rocks in geophysics, to interpreting depositional, microbiological, and environmental processes in sediments.Our research on FORC diagrams has
been supported over the years by the
U.S. National Science Foundation, the UK
Natural Environment Research Council,
the European Union, the Royal Society of
London, and the Australian Research
Council (grant DP120103952)
Frequency-dependent spin susceptibility in the two-dimensional Hubbard model
A Quantum Monte Carlo calculation of dynamical spin susceptibility in the
half-filled 2D Hubbard model is presented for temperature and an
intermediate on-site repulsion . Using the singular value decomposition
technique we succeed in analytically continuing the Matsubara Green's function
into the real frequency domain and in deriving the spectral representation for
the longitudinal and transverse spin susceptibility. The simulation results,
while contradicting the random-phase approximation prediction of
antiferromagnetic long-range order at this temperature, are in agreement with
an extension of a self-consistent renormalization approach of Moriya. The
static susceptibility calculated using this technique is qualitatively
consistent with the simulation results.Comment: 4 pages, Revtex, encoded figs.uu file with 3 figures enclose
- ā¦