6,958 research outputs found
Glass vessels from the Persian and Hellenistic Administrative Building at Tel Kedesh, Israel
Dispersive diffusion controlled distance dependent recombination in amorphous semiconductors
The photoluminescence in amorphous semiconductors decays according to power
law at long times. The photoluminescence is controlled by
dispersive transport of electrons. The latter is usually characterized by the
power of the transient current observed in the time-of-flight
experiments. Geminate recombination occurs by radiative tunneling which has a
distance dependence. In this paper, we formulate ways to calculate reaction
rates and survival probabilities in the case carriers execute dispersive
diffusion with long-range reactivity. The method is applied to obtain tunneling
recombination rates under dispersive diffusion. The theoretical condition of
observing the relation is obtained and theoretical
recombination rates are compared to the kinetics of observed photoluminescence
decay in the whole time range measured.Comment: To appear in Journal of Chemical Physic
Reluctance of general practice staff to register patients without documentation: a qualitative study in North East London.
BACKGROUND: Lack of access to documentation is a key barrier to GP registration, despite NHS England guidance stating that documents are not required. Staff attitudes and practice regarding registration of those without documentation are under- researched. AIM: To understand the processes through which registration might be refused for those without documents, and the factors operating to influence this. DESIGN AND SETTING: Qualitative study conducted in general practice across three clinical commissioning groups in North East London. METHOD: In total, 33 participants (GP staff involved in registering new patients) were recruited through email invitation. Semi-structured interviews and focus groups were conducted. Data were analysed using Braun and Clarke's reflexive thematic analysis. Two social theories informed this analysis: Lipsky's street-level bureaucracy and Bourdieu's theory of practice. RESULTS: Despite good knowledge of guidance, most participants expressed reluctance to register those without documentation, often introducing additional hurdles or requirements in their everyday practice. Two explanatory themes were generated: that those without documents were perceived as burdensome, and/or that moral judgements were made about their deservedness to finite resources. Participants described a context of high workload and insufficient funding. Some felt that GP services should be restricted by immigration status, as is widespread in secondary care. CONCLUSION: Improving inclusive registration practice requires addressing staff concerns, supporting navigation of high workloads, tackling financial disincentives to registering transient groups, and challenging narratives that undocumented migrants represent a 'threat' to NHS resources. Furthermore, it is imperative to acknowledge and address upstream drivers, in this instance the Hostile Environment
Exactly solvable model of a quantum spin glass
A mean field spherical model with random couplings between pairs, quartets,
and possibly higher multiplets of spins is considered. It has the same critical
behavior as the Sherrington-Kirkpatrick model. It thus exhibits replica
symmetry breaking. The order parameter function is solved exactly in the whole
low temperature phase. The zero field cooled susceptibility remains finite at
low . Next a quantum version of the system is considered. Whereas the
magnetic properties are not altered qualitatively, the thermodynamics is now
regular at small temperatures.Comment: 4 pages postscript. Revised version, to appear in Phys. Rev. Let
Thermo-oxidative Stability and Flammability of Three-dimensional Polymers Based on Olygocarbonate-methacrylates
By the irreversible condensation reaction of the mono-methacrylic
ester of ethylene glycol and chlorocarbonic esters of 2,2-dimethylpropandiol-
1,3 and 2,2-dimethylene chloride-propandiol-1,3,
two olygocarbonate methacrylate (OCM-I and -II, respectively)
containing unsaturated ends were synthesised. The polymerization
of OCM-I and OCM-II in the presence of cumene hydro.peroxide
and an accelerator gave two cross-liinked polymers Ln a yield
of 70-750/o. The thermal and thermo-oxidative decompositions of the prepared polymers were studied by the thermogravimetric method
and by characterization of the volatile pyrolysis products and the
nonvolatile polymer residue. The influence of the polymer
structure on the mechanism of the decomposition reactions in vacuo
as well as iin the presence of oxygen was discussed. The temperature
dependence of thermostabiLity was compared with some
polymer flammability parameters
Analytic Behaviour of Competition among Three Species
We analyse the classical model of competition between three species studied
by May and Leonard ({\it SIAM J Appl Math} \textbf{29} (1975) 243-256) with the
approaches of singularity analysis and symmetry analysis to identify values of
the parameters for which the system is integrable. We observe some striking
relations between critical values arising from the approach of dynamical
systems and the singularity and symmetry analyses.Comment: 14 pages, to appear in Journal of Nonlinear Mathematical Physic
- …