2,812 research outputs found
Why Not a Shared Database for Legal Serial Patterns?
Just as bibliographic records are shared by law libraries through a national database, serial publication pattern data could also be shared. The author presents a history of the movement toward such a database and offers a specific proposal for its creation
The LiAl/FeS2 battery power source for the future
Advanced high power density rechargeable batteries are currently under development. These batteries have the potential of greatly increasing the power and energy densities available for space applications. Depending on whether the system is optimized for high power or high energy, values up to 150 Wh/kg and 2100 W/kg (including hardware) are projected. This is due to the fact that the system uses a high conductivity molten salt electrolyte. The electrolyte also serves as a separator layer with unlimited freeze thaw capabilities. Life of 1000 cycles and ten calendar years is projected. The electrochemistry consists of a lithium aluminum alloy negative electrode, iron disulfide positive electrode, and magnesium oxide powder immobilized molten salt electrolyte. Processed powders are cold compacted into circular discs which are assembled into bipolar cell hardware with peripheral ceramic salts. The culmination of the work will be a high energy battery of 40 kWh and a high power battery of 28 kWh
Ratios of Elastic Scattering of Pions from 3H and 3He
We have measured the elastic-scattering ratios of normalized yields for
charged pions from 3H and 3He in the backward hemisphere. At 180 MeV, we
completed the angular distribution begun with our earlier measurements, adding
six data points in the angular range of 119 deg to 169 deg in the pi-nucleus
center of mass. We also measured an excitation function with data points at
142, 180, 220, and 256 MeV incident pion energy at the largest achievable angle
for each energy between 160 deg and 170 deg in the pi-nucleus center of mass.
This excitation function corresponds to the energies of our forward-hemisphere
studies. The data, taken as a whole, show an apparent role reversal of the two
charge-symmetric ratios r1 and r2 in the backward hemisphere. Also, for data >
100 deg we observe a strong dependence on the four-momentum transfer squared
(-t) for all of the ratios regardless of pion energy or scattering angle, and
we find that the superratio R data match very well with calculations based on
the forward-hemisphere data that predicts the value of the difference between
the even-nucleon radii of 3H and 3He. Comparisons are also made with recent
calculations incorporating different wave functions and double scattering
models.Comment: RevTex 8pages, 12 figure file
Involving disabled children and young people as partners in research: A systematic review
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Children and young people can be valuable partners in research, giving their unique perspectives on what and how research should be done. However, disabled children are less commonly involved in research than their non-disabled peers. This review investigated how disabled children have been involved as research partners; specifically how they have been recruited, the practicalities and challenges of involvement and how these have been overcome, and impacts of involvement for research, and disabled children and young people. The INVOLVE definition of involvement and the Equality and Human Rights Commission definition of disability were used. Relevant bibliographic databases were searched. Websites were searched for grey literature. Included studies had involved disabled children and young people aged 5-25 years in any study design. Reviews, guidelines, reports and other documents from the grey literature were eligible for inclusion. Twenty-two papers were included: seven reviews, eight original research papers, three reports, three guidelines and one webpage. Nine examples of involvement were identified. Recommendations included developing effective communication techniques, using flexible methods that can be adapted to needs and preferences, and ensuring that sufficient support and funding is available for researchers undertaking involvement. Positive impacts of involvement for disabled children included increased confidence, self-esteem and independence. Positive impacts for research were identified. Involving disabled children in research can present challenges; many of these can be overcome with sufficient time, planning and resources. More needs to be done to find ways to involve those with non-verbal communication. Generally, few details were reported about disabled children and young people's involvement in studies, and the quality of evidence was low. Although a range of positive impacts were identified, the majority of these were authors' opinions rather than data. There remains scope for methodological research to inform appropriate approaches to public and patient involvement in childhood disability research.CerebraNational Institute for Health Research (NIHR
Evaluation of serum galactomannan detection for diagnosis of feline upper respiratory tract aspergillosis
Measurement of serum galactomannan (GM), a polysaccharide fungal cell-wall component, is a non-invasive test for early diagnosis of invasive aspergillosis in humans. Feline upper respiratory tract (URT) aspergillosis is an emerging infectious disease in cats. Diagnosis requires biopsy for procurement of tissue specimens for cytological or histological detection of fungal hyphae and for fungal culture. The aim of this study was to evaluate serum GM measurement as a non-invasive diagnostic test for URT aspergillosis in cats. A one-stage, immunoenzymatic sandwich ELISA was used to detect serum GM in 4 groups of cats; Group 1 (URT aspergillosis) – confirmed URT aspergillosis (n=13, sinonasal aspergillosis (SNA) n=6, sino-orbital aspergillosis (SOA) n=7), Group 2 (URT other) – other URT diseases (n=15), Group 3 (β-lactam) – cats treated with β-lactam antibiotics for non-respiratory tract disease (n=14), Group 4a – healthy young cats (≤ 1y of age, n=28), Group 4b – healthy adult cats (>1 y of age, n=16). One cat with SNA and two cats with SOA caused by an Aspergillus fumigatus-mimetic species, tested positive for serum GM. For a cut-off optical density index of 1.5, the overall sensitivity and specificity of the assay was 23% and 78% respectively. False positive results occurred in 29 % of cats in Group 3 and 32% of cats in Group 4a. Specificity increased to 90% when Groups 3 and 4a were excluded from the analysis. Overall, serum GM measurement has a poor sensitivity but is a moderately specific, non-invasive screening test to rule out infection in patients with suspected feline upper respiratory tract aspergillosis.Feline Health Research Fund (FHRF
Overview of Pre-Congestion Notification Encoding
The objective of Pre-Congestion Notification (PCN) is to protect the quality of service (QoS) of inelastic flows within a Diffserv domain. On every link in the PCN-domain, the overall rate of PCN-traffic is metered, and PCN-packets are appropriately marked when certain configured rates are exceeded. Egress nodes provide decision points with information about the PCN-marks of PCN-packets that allows them to take decisions about whether to admit or block a new flow request, and to terminate some already admitted flows during serious pre-congestion. The PCN working group explored a number of approaches for encoding this pre-congestion information into the IP header. This document provides details of those approaches along with an explanation of the constraints that apply to any solution
Coherent photoproduction of pi(+) from He-3
We have measured the differential cross section for the gamma He-3 -\u3e pi(+)t reaction. This reaction was studied using the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with the Hall-B bremsstrahlung tagging system in the energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid He-3 target. The differential cross sections for the gamma He-3 -\u3e pi(+)t reaction were measured as a function of photon-beam energy and pion-scattering angle. Theoretical predictions to date cannot explain the large cross sections except at backward angles, showing that additional components must be added to the model
Charge Symmetry Violation Effects in Pion Scattering off the Deuteron
We discuss the theoretical and experimental situations for charge symmetry
violation (CSV) effects in the elastic scattering of pi+ and pi- on deuterium
(D) and 3He/3H. Accurate comparison of data for both types of targets provides
evidence for the presence of CSV effects. While there are indications of a CSV
effect in deuterium, it is much more pronounced in the case of 3He/3H. We
provide a description of the CSV effect on the deuteron in terms of single- and
double- scattering amplitudes. The Delta-mass splitting is taken into account.
Theoretical predictions are compared with existing experimental data for pi-d
scattering; a future article will speak to the pi-three nucleon case.Comment: 16 pages of RevTeX, 7 postscript figure
Charge-Symmetry Violation in Pion Scattering from Three-Body Nuclei
We discuss the experimental and theoretical status of charge-symmetry
violation (CSV) in the elastic scattering of pi+ and pi- on 3H and 3He.
Analysis of the experimental data for the ratios r1, r2, and R at Tpi = 142,
180, 220, and 256 MeV provides evidence for the presence of CSV. We describe
pion scattering from the three-nucleon system in terms of single- and
double-scattering amplitudes. External and internal Coulomb interactions as
well as the Delta-mass splitting are taken into account as sources of CSV.
Reasonable agreement between our theoretical calculations and the experimental
data is obtained for Tpi = 180, 220, and 256 MeV. For these energies, it is
found that the Delta-mass splitting and the internal Coulomb interaction are
the most important contributions for CSV in the three-nucleon system. The CSV
effects are rather sensitive to the choice of pion-nuclear scattering
mechanisms, but at the same time, our theoretical predictions are much less
sensitive to the choice of the nuclear wave function. It is found, however,
that data for r2 and R at Tpi = 142 MeV do not agree with the predictions of
our model, which may indicate that there are additional mechanisms for CSV
which are important only at lower energies.Comment: 26 pages of RevTeX, 16 postscript figure
Anomalous density dependence of static friction in sand
We measured experimentally the static friction force on the surface of
a glass rod immersed in dry sand. We observed that is extremely sensitive
to the closeness of packing of grains. A linear increase of the grain-density
yields to an exponentially increasing friction force. We also report on a novel
periodicity of during gradual pulling out of the rod. Our observations
demonstrate the central role of grain bridges and arches in the macroscopic
properties of granular packings.Comment: plain tex, 6 pages, to appear in Phys.Rev.
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