37,667 research outputs found
Ion-retarding lens improves the abundance sensitivity of tandem mass spectrometers
Ion-retarding lens which increases the abundance sensitivity of tandem magnetic-analyzer mass spectrometers measures isotopes of low abundance in mass positions adjacent to isotopes of high abundance. The lens increases the abundance sensitivity for isotopes lying farther from high abundance isotopes than the energy cutoff of the lens
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Higher education academic salaries in the UK
It is widely believed that higher education academic salaries are too low, and that this may lead to a âbrain drainâ and also lower quality in higher education, as universities fail to attract the âbrightest and the bestâ. We compare the salaries of Higher Education teaching professionals in the UK with those of other comparable professionals. We compare academic salaries to a range of occupational groupings that one might view as similar, in terms of unobserved characteristics, to academics. We conclude that HE teaching professionals earn lower earnings than most public sector graduates and do particularly poorly compared to most other comparable professionals. In particular, academic earnings compare poorly to those in the legal professions, consultant physicians and dental practitioners (across both the public and private sectors). On the other hand, some public sector workers do worse than HE academics, e.g. FE teachers
National Evaluation of the Capacity Building Programme in English Local Government: Annex 3. Direct Support in Poor and Weak Local Authorities: Emerging findings
This report summarises emerging findings from initial scoping analysis and case study fieldwork with authorities that have received Direct Support from the Capacity Building Programme (CBP) for local government. The report is one of a series of outputs from the national evaluation of the CBP, being undertaken by a team of researchers at the Policy Research Institute (PRI) at Leeds Metropolitan University and the Cities Research Unit at the University of West of England
Heat transport and flow structure in rotating Rayleigh-B\'enard convection
Here we summarize the results from our direct numerical simulations (DNS) and
experimental measurements on rotating Rayleigh-B\'enard (RB) convection. Our
experiments and simulations are performed in cylindrical samples with an aspect
ratio \Gamma varying from 1/2 to 2. Here \Gamma=D/L, where D and L are the
diameter and height of the sample, respectively. When the rotation rate is
increased, while a fixed temperature difference between the hot bottom and cold
top plate is maintained, a sharp increase in the heat transfer is observed
before the heat transfer drops drastically at stronger rotation rates. Here we
focus on the question of how the heat transfer enhancement with respect to the
non-rotating case depends on the Rayleigh number Ra, the Prandtl number Pr, and
the rotation rate, indicated by the Rossby number Ro. Special attention will be
given to the influence of the aspect ratio on the rotation rate that is
required to get heat transport enhancement. In addition, we will discuss the
relation between the heat transfer and the large scale flow structures that are
formed in the different regimes of rotating RB convection and how the different
regimes can be identified in experiments and simulations.Comment: 12 pages, 10 figure
A concurrent precursor inflow method for Large Eddy Simulations and applications to finite length wind farms
In order to enable simulations of developing wind turbine array boundary
layers with highly realistic inflow conditions a concurrent precursor method
for Large Eddy Simulations is proposed. In this method we consider two domains
simultaneously, i.e. in one domain a turbulent Atmospheric Boundary Layer (ABL)
without wind turbines is simulated in order to generate the turbulent inflow
conditions for a second domain in which the wind turbines are placed. The
benefit of this approach is that a) it avoids the need for large databases in
which the turbulent inflow conditions are stored and the correspondingly slow
I/O operations and b) we are sure that the simulations are not negatively
affected by statically swept fixed inflow fields or synthetic fields lacking
the proper ABL coherent structures. Sample applications are presented, in
which, in agreement with field data a strong decrease of the power output of
downstream wind-turbines with respect to the first row of wind-turbines is
observed for perfectly aligned inflow.Comment: 13 pages, 5 figure
Radial boundary layer structure and Nusselt number in Rayleigh-Benard convection
Results from direct numerical simulations for three dimensional
Rayleigh-Benard convection in a cylindrical cell of aspect ratio 1/2 and Pr=0.7
are presented. They span five decades of Ra from to . Good numerical resolution with grid spacing Kolmogorov
scale turns out to be crucial to accurately calculate the Nusselt number, which
is in good agreement with the experimental data by Niemela et al., Nature, 404,
837 (2000). In underresolved simulations the hot (cold) plumes travel further
from the bottom (top) plate than in the fully resolved case, because the
thermal dissipation close to the sidewall (where the grid cells are largest) is
insufficient. We compared the fully resolved thermal boundary layer profile
with the Prandtl-Blasius profile. We find that the boundary layer profile is
closer to the Prandtl Blasius profile at the cylinder axis than close to the
sidewall, due to rising plumes in that region.Comment: 10 pages, 6 figure
Sidewall effects in Rayleigh-B\'enard convection
We investigate the influence of the temperature boundary conditions at the
sidewall on the heat transport in Rayleigh-B\'enard (RB) convection using
direct numerical simulations. For relatively low Rayleigh numbers Ra the heat
transport is higher when the sidewall is isothermal, kept at a temperature
(where is the temperature difference between the
horizontal plates and the temperature of the cold plate), than when the
sidewall is adiabatic. The reason is that in the former case part of the heat
current avoids the thermal resistance of the fluid layer by escaping through
the sidewall that acts as a short-circuit. For higher Ra the bulk becomes more
isothermal and this reduces the heat current through the sidewall. Therefore
the heat flux in a cell with an isothermal sidewall converges to the value
obtained with an adiabatic sidewall for high enough Ra ().
However, when the sidewall temperature deviates from the heat
transport at the bottom and top plates is different from the value obtained
using an adiabatic sidewall. In this case the difference does not decrease with
increasing Ra thus indicating that the ambient temperature of the experimental
apparatus can influence the heat transfer. A similar behavior is observed when
only a very small sidewall region close to the horizontal plates is kept
isothermal, while the rest of the sidewall is adiabatic. The reason is that in
the region closest to the horizontal plates the temperature difference between
the fluid and the sidewall is highest. This suggests that one should be careful
with the placement of thermal shields outside the fluid sample to minimize
spurious heat currents.Comment: 27 pages, 16 figure
National Evaluation of the Capacity Building Programme in English Local Government: Annex 4: Follow On Study of Progress in Seven Case Study Improvement Partnerships
This report is one of a series of outputs from the national evaluation of the Capacity Building Programme for local government in England (CBP), being undertaken by a team of researchers at the Policy Research Institute (PRI) at Leeds Metropolitan University and the Cities Research Unit at the University of West of England. This report summarises the findings from the second phase of fieldwork with regional and sub-regional Improvement Partnerships, established to facilitate capacity building and improvement activity in local authorities. The research underpinning this report was undertaken in seven case study Improvement Partnerships (see Section 2) in October and November 2006 and follows a similar â baseline â exercise undertaken during the same period during 2005. It thus both draws on the earlier research (see Section 3) and identifies evidence of progress and impact (see Section 10) since the baseline phase
National Evaluation of the Capacity Building Programme in English Local Government: Annex 1. Seven Case Studies: The Pilot Programme
This report presents the findings of the evaluation of the Capacity Building pilots. The evaluation of the pilots is part of the on-going evaluation of the Capacity Building Programme and has been undertaken in the early scoping phase of the main evaluation in order to capture key learning points and insights into the programme. It is intended that the ongoing evaluation of the Capacity Building Programme will be formative and assist in the development of the programme over time. In what follows the background to the pilots programme is discussed, highlighting the kinds of capacity building activities the pilots are engaged with and the link between the Capacity Building Programme and the CPA. The report outlines the structure and purpose of the pilots programme and the nature and characteristics of the different pilots that were undertaken. The seven case studies are then discussed in more detail in the main body of 1 Introduction | 5 the report. These are drawn together in key themes and findings which can be used to strengthen future project development
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