1,902 research outputs found
A whole systems energy study - the Glasgow energy operator
Deep decarbonisation of local energy systems requires consideration of the contributions from multiple energy resources and networks, which may not be achievable by separate Network Operators acting in isolation. In this paper, the concept of the Local Energy System Operator (LESO) is introduced, acting to bridge between different Distribution Network Operators with a Whole System view of energy provision, and able to utilise assets in both electricity and gas networks. The LESO concept is demonstrated using a model representing the electricity and gas networks of the Glasgow City Council Area, and illustrates the ability of the LESO to optimise dispatch of assets across multiple carriers to achieve specific objectives in costs and emissions intensity, and to coordinate local investment in networks between DNOs. This bridging role is particularly appropriate to local municipalities such as Glasgow which have set ambitious near-term targets for emissions reduction, while not having direct control over the cost and emissions associated with upstream energy provision. Scenarios representing different future upstream energy system evolutionary pathways (such as mass electrification and gas grid decarbonisation) are simulated and indicate the means by which local emissions reduction may be achieved in both operational and planning timescales via joint dispatch/planning of electricity and gas networks in order to avoid stranded assets and unnecessary sunk costs. Within operational timescales, hybrid systems such as heat networks may be dispatched to make optimal use of network headroom, which can then further inform the level of emissions reduction which will be realised through specific volumes of network investment, and where they might best be directed. The inability of the LESO to control upstream emissions means that the rate of decarbonisation is still constrained by the emissions intensity of transmission-connected energy resources – however, as there is no implicit central planning role in deregulated energy markets, a local coordinating role is seen as key to making best use of heterogeneous regional and local energy systems, and interfacing with centralised actors to best realised the energy transition
Paying clinicians to join clinical trials : a review of guidelines and interview study of trialists
Background: The motivations of clinicians to participate in clinical trials have been little studied. This project explored the potential role of payment for participation in publicly funded clinical trials in the UK. The aims were to review relevant guidelines and to collate and analyse views of clinical trialists on the role of payments and other factors that motivated clinicians to join clinical trials.
Methods: Review of guidelines governing payments to clinicians for recruitment to trials. Semistructured
interviews with a range of NHS clinical trial leaders, analysed using qualititative methods.
Results: While UK guidelines had little to say specifically on payments linked to recruitment, all payments have become highly regulated and increasingly transparent. Interview participants believed that expenses arising from research should be covered. Payments in excess of expenses
were seen as likely to increase participation but with the risk of reducing quality. Motivations such
as interest in the topic, the scope for patients to benefit and intellectual curiosity were considered more important. Barriers to involvement included bureaucracy and lack of time.
Discussion: Limited scope exists for paying clinicians over-and-above the cost of their time to be involved in research. Most trialists favour full payment of all expenses related to research.
Conclusion: Payment of clinicians beyond expenses is perceived to be a less important motivating factor than researching important, salient questions, and facilitating research by reducing bureaucracy and delay
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Survey to explore understanding of the principles of aseptic technique: Qualitative content analysis with descriptive analysis of confidence and training
BACKGROUND: In many countries, aseptic procedures are undertaken by nurses in the general ward setting, but variation in practice has been reported, and evidence indicates that the principles underpinning aseptic technique are not well understood.
METHODS: A survey was conducted, employing a brief, purpose-designed, self-reported questionnaire.
RESULTS: The response rate was 72%. Of those responding, 65% of nurses described aseptic technique in terms of the procedure used to undertake it, and 46% understood the principles of asepsis. The related concepts of cleanliness and sterilization were frequently confused with one another. Additionally, 72% reported that they not had received training for at least 5 years; 92% were confident of their ability to apply aseptic technique; and 90% reported that they had not been reassessed since their initial training. Qualitative analysis confirmed a lack of clarity about the meaning of aseptic technique.
CONCLUSION: Nurses' understanding of aseptic technique and the concepts of sterility and cleanliness is inadequate, a finding in line with results of previous studies. This knowledge gap potentially places patients at risk. Nurses' understanding of the principles of asepsis could be improved. Further studies should establish the generalizability of the study findings. Possible improvements include renewed emphasis during initial nurse education, greater opportunity for updating knowledge and skills post-qualification, and audit of practice
Chiral extrapolation of lattice moments of proton quark distributions
We present the resolution of a long-standing discrepancy between the moments
of parton distributions calculated from lattice QCD and their experimental
values. We propose a simple extrapolation formula for the moments of the
nonsinglet quark distribution u-d, as a function of quark mass, which embodies
the general constraints imposed by the chiral symmetry of QCD. The inclusion of
the leading nonanalytic behavior leads to an excellent description of both the
lattice data and the experimental values of the moments.Comment: 9 pages, 1 figure, to appear in Physical Review Letter
dbar/ubar Asymmetry and the Origin of the Nucleon Sea
The Drell-Yan cross section ratios, , measured in
Fermilab E866, have led to the first determination of ,
, and the integral of for the
proton over the range . The E866 results are compared
with predictions based on parton distribution functions and various theoretical
models. The relationship between the E866 results and the NMC measurement of
the Gottfried integral is discussed. The agreement between the E866 results and
models employing virtual mesons indicates these non-perturbative processes play
an important role in the origin of the , asymmetry in the
nucleon sea.Comment: 5 pages, 3 figures, ReVTe
An Alternative Method to Obtain the Quark Polarization of the Nucleon
An alternate method is described to extract the quark contribution to the
spin of the nucleon directly from the first moment of the deuteron structure
function, . It is obtained without recourse to the use of input on the
nucleon wave function from hyperon decays involving the flavor symmetry
parameters, F and D. The result for the quark polarization of the nucleon,
is in good agreement with the values of the singlet axial
current matrix element, , obtained from recent next-to-leading order
analyses of current proton, neutron and deuteron data.Comment: 7 pages, 1 figur
Progress in neutrino oscillation searches and their implications
Neutrino Oscillation, in which a given flavour of neutrino transforms into
another is a powerful tool for probing small neutrino masses. The intrinsic
neutrino properties involved are neutrino mass squared difference
and the mixing angle in vacuum . In this talk I will summarize the
progress that we have achieved in our search for neutrino oscillation with
special emphasis on the recent results from the Sudbury Neutrino Observatory
(SNO) on the measurement of solar neutrino fluxes. I will outline the current
bounds on the neutrino masses and mixing parameters and discuss the major
physics goals of future neutrino experiments in the context of the present
picture.Comment: Plenary Talk, WHEPP-7, January 2002, published in Pramana, Vol. 60,
261, 200
Polarized light-flavor antiquarks from Drell-Yan processes of h+\vec{N}\to\vec{l^{+-}} + l^{-+} + X
We propose a formula to determine the first moment of difference between the
polarized - and -quarks in the nucleon, {\it i.e.} from the Drell-Yan processes in collisions of unpolarized
hadrons with longitudinally polarized nucleons by measuring outgoing lepton
helicities. As coefficients in the differential cross section depend on the
- and -quark numbers in the unpolarized hadron beam, the difference
can be independently tested by changing the hadron
beam. Moreover, a formula for estimating the -factor in Drell-Yan processes
is also suggested.Comment: 10 pages, 1 figur
Do we expect light flavor sea-quark asymmetry also for the spin-dependent distribution functions of the nucleon?
After taking account of the scale dependence by means of the standard DGLAP
evolution equation, the theoretical predictions of the chiral quark soliton
model for the unpolarized and longitudinally polarized structure functions of
the nucleon are compared with the recent high energy data. The theory is shown
to explain all the qualitative features of the experiments, including the NMC
data for , , the Hermes and NuSea
data for , the EMC and SMC data for ,
and . Among others, flavor asymmetry of the longitudinally
polarized sea-quark distributions is a remarkable prediction of this model,
i.e., it predicts that with a sizable negative coefficient
(and ) in qualitative consistency with the recent
semi-phenomenological analysis by Morii and Yamanishi.Comment: 14pages, including 5 eps_figures with epsbox.sty, late
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