1,391 research outputs found
Development of low temperature dielectric coatings for electrical conductors thirteenth quarterly report
Dielectric loss and connector problems at cryogenic temperatur
Study made of dielectric properties of promising materials for cryogenic capacitors
Experimental investigations were conducted to determine dielectric properties of promising materials for cryogenic capacitors to be used in energy storage and pulse applications. The three classes of materials investigated were inorganic bonded ferroelectric materials, anodic coatings on metal foils, and polar low temperature liquids
Evaluation of thin wall spacecraft electrical wiring. Volume I - Test methods and facilities Technical report no. 1
Test methods and facilities used in evaluating performance characteristics of thin wall spacecraft electric wiring under simulated spacecraft environment
Cryogenic capacitor investigation Final report
Electrical and mechanical properties data on dielectrics to estimate parameters of cryogenic capacitor
Evaluation of thin wall spacecraft electrical wiring. Volume II - Test results and facilities Technical report no. 1
Insulation resistance of spacecraft wiring against abrasion, radiation effects, oxygen environment, and extrusion lubricant
Evaluation of thin wall spacecraft electrical wiring. Volume II - Summary and conclusions Final report
Performance characteristics environmentally determined for spacecraft, thin wall wiring - summary and conclusion
Evaluation of thin wall spacecraft electrical wiring. Volume I - Test results Final report
Performance characteristics environmentally determined for spacecraft, thin wall wirin
Test beam Characterizations of 3D Silicon Pixel detectors
3D silicon detectors are characterized by cylindrical electrodes
perpendicular to the surface and penetrating into the bulk material in contrast
to standard Si detectors with planar electrodes on its top and bottom. This
geometry renders them particularly interesting to be used in environments where
standard silicon detectors have limitations, such as for example the radiation
environment expected in an LHC upgrade. For the first time, several 3D sensors
were assembled as hybrid pixel detectors using the ATLAS-pixel front-end chip
and readout electronics. Devices with different electrode configurations have
been characterized in a 100 GeV pion beam at the CERN SPS. Here we report
results on unirradiated devices with three 3D electrodes per 50 x 400 um2 pixel
area. Full charge collection is obtained already with comparatively low bias
voltages around 10 V. Spatial resolution with binary readout is obtained as
expected from the cell dimensions. Efficiencies of 95.9% +- 0.1 % for tracks
parallel to the electrodes and of 99.9% +- 0.1 % at 15 degrees are measured.
The homogeneity of the efficiency over the pixel area and charge sharing are
characterized.Comment: 5 pages, 7 figure
The development and evaluation of an online application to assist in the extraction of data from graphs for use in systematic reviews
These are the data we generated in our evaluation of the graphical user interface.
Please see our publication on Wellcome Open Research for information about the evaluations.These are the data we generated in our evaluation of the graphical user interface. Please see our publication on Wellcome Open Research for information about the evaluations
BLUF Domain Function Does Not Require a Metastable Radical Intermediate State
BLUF
(blue light using flavin) domain proteins are an important
family of blue light-sensing proteins which control a wide variety
of functions in cells. The primary light-activated step in the BLUF
domain is not yet established. A number of experimental and theoretical
studies points to a role for photoinduced electron transfer (PET)
between a highly conserved tyrosine and the flavin chromophore to
form a radical intermediate state. Here we investigate the role of
PET in three different BLUF proteins, using ultrafast broadband transient
infrared spectroscopy. We characterize and identify infrared active
marker modes for excited and ground state species and use them to
record photochemical dynamics in the proteins. We also generate mutants
which unambiguously show PET and, through isotope labeling of the
protein and the chromophore, are able to assign modes characteristic
of both flavin and protein radical states. We find that these radical
intermediates are not observed in two of the three BLUF domains studied,
casting doubt on the importance of the formation of a population of
radical intermediates in the BLUF photocycle. Further, unnatural amino
acid mutagenesis is used to replace the conserved tyrosine with fluorotyrosines,
thus modifying the driving force for the proposed electron transfer
reaction; the rate changes observed are also not consistent with a
PET mechanism. Thus, while intermediates of PET reactions can be observed
in BLUF proteins they are not correlated with photoactivity, suggesting
that radical intermediates are not central to their operation. Alternative
nonradical pathways including a keto–enol tautomerization induced
by electronic excitation of the flavin ring are considered
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