2,765 research outputs found
The Thermal Environment of the Fiber Glass Dome for the New Solar Telescope at Big Bear Solar Observatory
The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope
with an equatorial mount and an open optical support structure. To mitigate the
temperature fluctuations along the exposed optical path, the effects of
local/dome-related seeing have to be minimized. To accomplish this, NST will be
housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents
evenly spaced around its perimeter. The 14 vents house louvers that open and
close independently of one another to regulate and direct the passage of air
through the dome. In January 2006, 16 thermal probes were installed throughout
the dome and the temperature distribution was measured. The measurements
confirmed the existence of a strong thermal gradient on the order of 5 degree
Celsius inside the dome. In December 2006, a second set of temperature
measurements were made using different louver configurations. In this study, we
present the results of these measurements along with their integration into the
thermal control system (ThCS) and the overall telescope control system (TCS).Comment: 12 pages, 11 figures, submitted to SPIE Optics+Photonics, San Diego,
U.S.A., 26-30 August 2007, Conference: Solar Physics and Space Weather
Instrumentation II, Proceedings of SPIE Volume 6689, Paper #2
Linking consumer datasets to chart residential moves in private rental housing in England and Wales
With sufficient preparation for purpose, consumer datasets may be used alongside conventional statistical sources to provide more granular and frequently updated estimates of housing market conditions than are otherwise available. Here we describe linkage of Zoopla rental market listings and Linked Consumer Register data to establish the pattern of residential moves in England and Wales between 2014-2019
Angular dependent vortex pinning mechanisms in YBCO coated conductors and thin films
We present a comparative study of the angular dependent critical current
density in YBa2Cu3O7 films deposited on IBAD MgO and on single crystal MgO and
SrTiO3 substrates. We identify three angular regimes where pinning is dominated
by different types of correlated and uncorrelated defects. We show that those
regimes are present in all cases, indicating that the pinning mechanisms are
the same, but their extension and characteristics are sample dependent,
reflecting the quantitative differences in texture and defect density. In
particular, the more defective nature of the films on IBAD turns into an
advantage as it results in stronger vortex pinning, demonstrating that the
critical current density of the films on single crystals is not an upper limit
for the performance of the IBAD coated conductors.Comment: 14 pages, 3 figures. Submitted to AP
An evaluation of an educational intervention (physical assessment module), for the non medical work force to provide unscheduled services across the primary and secondary sector in one SHA
The purpose of this research was to establish how an educational intervention (the physical assessment module) enabled practitioners, drawn from the non medical workforce, to meet the modernising agenda of new ways of working, notably, to provide unscheduled care and to contribute to the transformation of chronic care provision in the acute care sector and Community.To gauge the impact of the physical assessment module on the evolution of competencies to fulfil the demands of new roles in practice a responsive evaluation model was used. Data were gathered from face to face interviews, analysis of relevant documents, and direct observation of working practises. Importantly the approach sought to report findings back into the communities from which these data have arisen to verify the findings but also to enrich and update issues in a rapidly changing context. Therefore, feedback via stakeholder conferences was a critical element in the process.Data were analysed using the constant comparative method. Data analysis ran concurrently with data collection and as emergent issues arose they were abstracted and the topics explored in subsequent interviews.Key findings are presented in three tiers: from theory to practice (learning physical assessment skills and techniques and applying these in practice; from policy to practice (tracking the way in which policy was transmitted from the central government through to organisations and how this impacted on the context in which the practitioners were required to use their skills; and finally from policy to users of the service (examining the evaluation of patients and their relatives about the services provided by nurses undertaking advanced physical assessment skills
Kearns-sayre syndrome with reduced plasma and cerebrospinal fluid folate
A young woman with Kearns-Sayre syndrome and progressive central nervous system deterioration over 15 years had decreased plasma and cerebrospinal fluid folate levels while receiving phenytoin for a seizure disorder. A muscle biopsy showed a âragged red fiberâ myopathy with reduced muscle carnitine and mitochondrial enzymes. Computed tomographic brain scans showed cerebral white matter hypodensities and bilateral calcification of the basal ganglia. The mechanism for the folate deficiency and altered ratio of plasma to cerebrospinal fluid folate is unknown, but the deficiency may be responsive to replacement therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50301/1/410130620_ftp.pd
Why does the Engel method work? Food demand, economies of size and household survey methods
Estimates of household size economies are needed for the analysis of poverty and inequality. This paper shows that Engel estimates of size economies are large when household expenditures are obtained by respondent recall but small when expenditures are obtained by daily recording in diaries. Expenditure estimates from recall surveys appear to have measurement errors correlated with household size. As well as demonstrating the fragility of Engel estimates of size economies, these results help resolve a puzzle raised by Deaton and Paxson (1998) about differences between rich and poor countries in the effect of household size on food demand
Working group written presentation: Trapped radiation effects
The results of the Trapped Radiation Effects Panel for the Space Environmental Effects on Materials Workshop are presented. The needs of the space community for new data regarding effects of the space environment on materials, including electronics are listed. A series of questions asked of each of the panels at the workshop are addressed. Areas of research which should be pursued to satisfy the requirements for better knowledge of the environment and better understanding of the effects of the energetic charged particle environment on new materials and advanced electronics technology are suggested
Unravelling the mechanisms of vibrational relaxation in solution
We present a systematic study of the mode-specific vibrational relaxation of NO(2) in six weakly-interacting solvents (perfluorohexane, perfluoromethylcyclohexane, perfluorodecalin, carbon tetrachloride, chloroform, and d-chloroform), chosen to elucidate the dominant energy transfer mechanisms in the solution phase. Broadband transient vibrational absorption spectroscopy has allowed us to extract quantum state-resolved relaxation dynamics of the two distinct NO(2) fragments produced from the 340 nm photolysis of N(2)O(4) â NO(2)(X) + NO(2)(A) and their separate paths to thermal equilibrium. Distinct relaxation pathways are observed for the NO(2) bending and stretching modes, even at energies as high as 7000 cm(â1) above the potential minimum. Vibrational energy transfer is governed by different interaction mechanisms in the various solvent environments, and proceeds with timescales ranging from 20â1100 ps. NO(2) relaxation rates in the perfluorocarbon solvents are identical despite differences in acceptor mode state densities, infrared absorption cross sections, and local solvent structure. Vibrational energy is shown to be transferred to non-vibrational solvent degrees of freedom (V-T) through impulsive collisions with the perfluorocarbon molecules. Conversely, NO(2) relaxation in chlorinated solvents is reliant on vibrational resonances (V-V) while V-T energy transfer is inefficient and thermal excitation of the surrounding solvent molecules inhibits faster vibrational relaxation through direct complexation. Intramolecular vibrational redistribution allows the symmetric stretch of NO(2) to act as a gateway for antisymmetric stretch energy to exit the molecule. This study establishes an unprecedented level of detail for the cooling dynamics of a solvated small molecule, and provides a benchmark system for future theoretical studies of vibrational relaxation processes in solution
Gluino Contribution to the 3-loop QCD beta function in the Minimal Supersymmetric Standard Model
We deduce the gluino contribution to the three-loop QCD \beta function within
the minimal supersymmetric Standard Model (MSSM) from its standard QCD
expression. The result is a first step in the computation of the full MSSM
three-loop \beta function. In addition, in the case of a light gluino it
provides the strong three-loop SUSY correction to the extrapolation of the
strong coupling constant from the low energy regime to the Z region and up to
the squark threshold.Comment: 11 pages, RevTex, 4 Postscript figur
Search for a T-odd, P-even Triple Correlation in Neutron Decay
Background: Time-reversal-invariance violation, or equivalently CP violation,
may explain the observed cosmological baryon asymmetry as well as signal
physics beyond the Standard Model. In the decay of polarized neutrons, the
triple correlation D\cdot(p_{e}\timesp_{\nu}) is a parity-even,
time-reversal- odd observable that is uniquely sensitive to the relative phase
of the axial-vector amplitude with respect to the vector amplitude. The triple
correlation is also sensitive to possible contributions from scalar and tensor
amplitudes. Final-state effects also contribute to D at the level of 1e-5 and
can be calculated with a precision of 1% or better. Purpose: We have improved
the sensitivity to T-odd, P-even interactions in nuclear beta decay. Methods:
We measured proton-electron coincidences from decays of longitudinally
polarized neutrons with a highly symmetric detector array designed to cancel
the time-reversal-even, parity-odd Standard-Model contributions to polarized
neutron decay. Over 300 million proton-electron coincidence events were used to
extract D and study systematic effects in a blind analysis. Results: We find D
= [-0.94\pm1.89(stat)\pm0.97(sys)]e-4. Conclusions: This is the most sensitive
measurement of D in nuclear beta decay. Our result can be interpreted as a
measurement of the phase of the ratio of the axial-vector and vector coupling
constants (CA/CV= |{\lambda}|exp(i{\phi}_AV)) with {\phi}_AV = 180.012{\deg}
\pm0.028{\deg} (68% confidence level) or to constrain time-reversal violating
scalar and tensor interactions that arise in certain extensions to the Standard
Model such as leptoquarks. This paper presents details of the experiment,
analysis, and systematic- error corrections.Comment: 21 pages, 22 figure
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