777 research outputs found
Superconducting properties of the In-substituted topological crystalline insulator, SnTe
We report detailed investigations of the properties of a superconductor obtained by substituting In at the Sn site in the topological crystalline insulator (TCI), SnTe. Transport, magnetization and heat capacity measurements have been performed on crystals of SnInTe, which is shown to be a bulk superconductor with at ~K and at ~K. The upper and lower critical fields are estimated to be ~T and ~mT respectively, while indicates this material is a strongly type II superconductor
Magneto-elastic coupling and competing entropy changes in substituted CoMnSi metamagnets
We use neutron diffraction, magnetometry and low temperature heat capacity to
probe giant magneto-elastic coupling in CoMnSi-based antiferromagnets and to
establish the origin of the entropy change that occurs at the metamagnetic
transition in such compounds. We find a large difference between the electronic
density of states of the antiferromagnetic and high magnetisation states. The
magnetic field-induced entropy change is composed of this contribution and a
significant counteracting lattice component, deduced from the presence of
negative magnetostriction. In calculating the electronic entropy change, we
note the importance of using an accurate model of the electronic density of
states, which here varies rapidly close to the Fermi energy.Comment: 11 pages, 9 figures. Figures 4 and 6 were updated in v2 of this
preprint. In v3, figures 1 and 2 have been updated, while Table II and the
abstract have been extended. In v4, Table I has updated with relevant neutron
diffraction dat
Influence of the Secondary Arc on the Operation of Single Phase Autoreclosure of the 400 kV interconnection between Hungary and Croatia
Faults on EHV lines are generally single-phase-to-ground ones and not permanent in the majority of
cases. Thus single phase auto reclosure (SPAR), at which the faulty phases are tripped for a short time,
eliminates the predominant part of the faults [1,2]. The secondary arc, which follows the high power
arc after tripping the faulty phases at both side of the line may endanger the successfulness of
reclosing if the duration of the switched off interval (dead time) is not long enough to ensure the
extinction of the arc. The secondary arcing times recorded on different EHV lines or measured in
laboratory tests show significant spread, consequently, to select a dead time according to the longest
experimental secondary arc extinction time is not feasible.
During commissioning of the double circuit 420 kV interconnection between Hungary and Croatia
several staged faults were initiated to analyze the arc extinction performance. Initially the line was in
operation by connecting the two circuits in parallel along the 1/3rd of the full length. In this
configuration the longest secondary arc extinction time was 4 seconds and the secondary arc has not
extinguished in 27s in one of the tests, so the line had to be tripped out to clear the staged fault. Later
on, the length of the Croatian section of the line has been significantly shortened after putting a new
substation into service. The increased performance of SPAR of the new arrangement has been proved
with field tests.
A realistic representation of the secondary arcs is essential in determining the auto-reclosure
performance of EHV transmission lines. As shown in the paper, the random variation of the arc
parameters influences significantly the arc extinction time. The results of the field tests confirmed the
importance of the distributed nature of the transmission line and the nonlinear characteristic of the arc
resistance in the intermittent region of arcing, where temporary extinctions and sudden re-ignitions in
the arc channel produce transient wave processes along the line
Effect of an educational program in primary care: the case of lipid control in cardio-cerebrovascular prevention.
Lowering blood cholesterol levels reduces the risk of coronary heart disease. However, the effect of interventions depends on the patients' adherence to treatment. Primary care plays an important role in the detection, treatment and monitoring of disease, therefore different educational programs (EP) have been implemented to improve disease management in general practice. The present study is aimed to assess whether a general practitioner auditing and feedback EP may improve dyslipidaemia management in a primary care setting and to evaluate patients' adherence to prescribed lipid-lowering treatment. The quality of cardiovascular and cerebrovascular disease prevention before and after the implementation of an EP offered to 25 general practitioners (GPs), was evaluated. Clinical and prescription data on patients receiving at least one lipid-lowering treatment was collected. To evaluate the quality of the healthcare service provided, clinical and biochemical outcomes, and drug-utilization, process indicators were set up. Adherence was evaluated before and after the EP as the "Medication Possession Ratio" (MPR). A correlation analysis was carried out to estimate the effect of the MPR in achieving pre-defined clinical end-points. Prescription data for lipid-lowering drugs was collected in a sample of 839 patients. While no differences in the achievement of blood lipid targets were observed, a slight but significant improvement of the MPR was registered after the EP (MPR >0.8=64.2% vs 60.6%, p=0.0426). Moreover, high levels of statin adherence were associated with the achievement of total blood cholesterol target (OR=3.3 for MPR >0.8 vs MPR 0.8 vs MPR <0.5,95% CI: 1.5–7.2). The EP partially improved the defined clinical targets; probably, a more patient-based approach could be more appropriate to achieve the defined target. Further studies are needed to identify how healthcare services can be improved
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