2,302 research outputs found
Investigation of charge coupled device correlation techniques
Analog Charge Transfer Devices (CTD's) offer unique advantages to signal processing systems, which often have large development costs, making it desirable to define those devices which can be developed for general system's use. Such devices are best identified and developed early to give system's designers some interchangeable subsystem blocks, not requiring additional individual development for each new signal processing system. The objective of this work is to describe a discrete analog signal processing device with a reasonably broad system use and to implement its design, fabrication, and testing
New proton polarized structure functions in charged current processes at HERA
Estimates for longitudinal spin asymmetries which single out new polarized
nucleon structure functions in deeply inelastic charged current interactions at
HERA energies are given, exploiting their interpretation in terms of polarized
quark distributions. These asymmetries turn out to be large and allow a
measurement of the new polarized structure functions and ,
which would add valuable tests and information on the spin content of quarks
inside a polarized proton. We also show that single spin asymmetries in neutral
current interactions are very small.Comment: LaTeX, 8 pages, 6 figure
MOD-0A 200 kW wind turbine generator design and analysis report
The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented
The MOD-OA 200 kilowatt wind turbine generator design and analysis report
The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed
On the consistency of neutron-star radius measurements from thermonuclear bursts
The radius of neutron stars can in principle be measured via the
normalisation of a blackbody fitted to the X-ray spectrum during thermonuclear
(type-I) X-ray bursts, although few previous studies have addressed the
reliability of such measurements. Here we examine the apparent radius in a
homogeneous sample of long, mixed H/He bursts from the low-mass X-ray binaries
GS 1826-24 and KS 1731-26. The measured blackbody normalisation (proportional
to the emitting area) in these bursts is constant over a period of up to 60s in
the burst tail, even though the flux (blackbody temperature) decreased by a
factor of 60-75% (30-40%). The typical rms variation in the mean normalisation
from burst to burst was 3-5%, although a variation of 17% was found between
bursts observed from GS 1826-24 in two epochs. A comparison of the
time-resolved spectroscopic measurements during bursts from the two epochs
shows that the normalisation evolves consistently through the burst rise and
peak, but subsequently increases further in the earlier epoch bursts. The
elevated normalisation values may arise from a change in the anisotropy of the
burst emission, or alternatively variations in the spectral correction factor,
f_c, of order 10%. Since burst samples observed from systems other than GS
1826-24 are more heterogeneous, we expect that systematic uncertainties of at
least 10% are likely to apply generally to measurements of neutron-star radii,
unless the effects described here can be corrected for.Comment: 9 pages, 6 figures; accepted by Ap
Treatment exhaustion of highly active antiretroviral therapy (HAART) among individuals infected with HIV in the United Kingdon: multicentre cohort study
Objectives:
To investigate whether there is evidence that an increasing proportion of HIV infected patients is starting to experience increases in viral load and decreases in CD4 cell count that are consistent with exhaustion of available treatment options.
Design:
Multicentre cohort study.
Setting:
Six large HIV treatment centres in southeast England.
Participants:
All individuals seen for care between 1 January 1996 and 31 December 2002.
Main outcome measures:
Exposure to individual antiretroviral drugs and drug classes, CD4 count, plasma HIV RNA burden.
Results:
Information is available on 16 593 individuals (13 378 (80.6%) male patients, 10 340 (62.3%) infected via homosexual or bisexual sex, 4426 (26.7%) infected via heterosexual sex, median age 34 years). Overall, 10 207 of the 16 593 patients (61.5%) have been exposed to any antiretroviral therapy. This proportion increased from 41.2% of patients under follow up at the end of 1996 to 71.3% of those under follow up in 2002. The median CD4 count and HIV RNA burden of patients under follow up in each year changed from 270 cells/mm3 and 4.34 log10 copies/ml in 1996 to 408 cells/mm3 and 1.89 log10 copies/ml, respectively, in 2002. By 2002, 3060 (38%) of patients who had ever been treated with antiretroviral therapy had experienced all three main classes. Of these, around one quarter had evidence of “viral load failure” with all these three classes. Patients with three class failure were more likely to have an HIV RNA burden > 2.7 log10 copies/ml and a CD4 count < 200 cells/mm3.
Conclusions:
The proportion of individuals with HIV infection in the United Kingdom who have been treated has increased gradually over time. A substantial proportion of these patients seem to be in danger of exhausting their options for antiretroviral treatment. New drugs with low toxicity, which are not associated with cross resistance to existing drugs, are urgently needed for such patients
Flavor Asymmetry of the Polarized Light Sea: Models vs. Data
The flavor asymmetry of the polarized light sea, , discriminates between different model calculations of helicity densities.
We show that the chiral chromodielectric model, differently from models based
on a expansion, predicts a small value for this asymmetry, what seems
in agreement with preliminary HERMES data.Comment: 10 pages, 3 figure
Fentanyl analytics in a case of fatal misuse of transdermal fentanyl
Abstract A 54-year old male (90 kg) was found in his bedroom with a fentanyl transdermal patch on his penis. With low vital reactions, the dormant man was immediately brought to hospital, where he died shortly. Systematic toxicological analysis confirmed a fatal poisoning with fentanyl. The fentanyl concentration in blood was 35.1 µg/L (LC-MS-MS). The presented case demonstrated the possibility of fentanyl misuse with a transdermal patch at a place of possibel high resorption and fatal outcome. Death due to the application of fentanyl transdermal system which was patched on the penis has not been previously reported
Natal dispersal based on past and present environmental phenology in the pied flycatcher (Ficedula hypoleuca)
this is the postprint version of the article. the published version of the article can be found at www.springerlink.comNatal dispersal allows individuals to reach suitable
breeding sites. The effect of present plant phenology
as a cue for dispersal into areas with favourable stages of
development has been well established across avian and
mammalian taxa. However, the effect of past experience is
less understood. We studied the effect of past and present
phenology of the environment on the direction and distance
of natal dispersal in a passerine bird, the pied flycatcher
(Ficedula hypoleuca). We monitored spring settlement of
local recruits in six nest box plots along a 10-km stretch of
a south-north gradient of plant and caterpillar food development.
We found that males used both past experience of
caterpillar phenology from early life and actual plant phenology
during the recruitment season as independent cues
for breeding settlement. Males that had experienced a mismatch
with the caterpillar food peak as a nestling, and/or
those that arrived late in the spring in the recruitment year,
moved north of their natal site, whereas males that had
experienced a better match with the caterpillars as a nestling,
and/or those that migrated earlier in the spring, settled
at a similar site or more to the south. In females, no such effects were found, suggesting that the usage of phenological
cues is sex specific. In summary, tracking environmental
phenology by natal dispersal may represent an effective
mechanism for settling in new favourable areas, and may
thus potentially cause rapid change of a species’ geographical
breeding range in response to climate change.2014-12-3
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