4,229 research outputs found
Digital memory sense amplifying means Patent
Digital magnetic core memory with sensing amplifier circuit
Transfluxor circuit amplifies sensing current for computer memories
To transfer data from the magnetic memory core to an independent core, a reliable sensing amplifier has been developed. Later the data in the independent core is transferred to the arithmetical section of the computer
The Anomalous Temporal Behaviour of Broadband Ly Emission During Solar Flares From SDO/EVE
Despite being the most prominent emission line in the solar spectrum, there
has been a notable lack of studies devoted to variations in Ly emission
during solar flares in recent years. However, the few examples that do exist
have shown Ly emission to be a substantial radiator of the total energy
budget of solar flares (on the order of 10%). It is also a known driver of
fluctuations in earth's ionosphere. The EUV Variability Experiment (EVE)
onboard the Solar Dynamics Observatory now provides broadband, photometric
Ly data at 10 s cadence with its Multiple EUV Grating
Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar
flares in the 5 years since it was launched. However, the MEGS-P time profiles
appear to display a rise time of tens of minutes around the time of the flare
onset. This is in stark contrast to the rapid, impulsive increase observed in
other intrinsically chromospheric features (H, Ly, LyC, C III,
etc.). Furthermore, the emission detected by MEGS-P peaks around the time of
the peak of thermal soft X-ray emission, rather than during the impulsive phase
when energy deposition in the chromosphere - often assumed to be in the form of
nonthermal electrons - is greatest. Given that spectrally-resolved Ly
observations during flares from SORCE/SOLSTICE peak during the impulsive phase
as expected, this suggests that the atypical behaviour of MEGS-P data is a
manifestation of the broadband nature of the observations. This could imply
that other lines and/or continuum emission that becomes enhanced during flares
could be contributing to the passband. Users are hereby urged to exercise
caution when interpreting broadband Ly observations of solar flares.
Comparisons have also been made with other broadband Ly photometers
such as PROBA2/LYRA and GOES/EUVS-E.Comment: Submitted to A&A Research Notes, 5 pages 4 figure
Foam composite structures
The need to include fire resistant foams into state of the art aircraft interior paneling to increase passenger safety in aircraft fires was studied. Present efforts were directed toward mechanical and fire testing of panels with foam inclusions. Skinned foam filled honeycomb and PBI structural foams were the two constructions investigated with attention being directed toward weight/performance/cost trade-off. All of the new panels demonstrated improved performance in fire and some were lighter weight but not as strong as the presently used paneling. Continued efforts should result in improved paneling for passenger safety. In particular the simple partial filling (fire side) of state-of-the-art honeycomb with fire resistant foams with little sacrifice in weight would result in panels with increased fire resistance. More important may be the retarded rate of toxic gas evolution in the fire due to the protection of the honeycomb by the foam
Low cycle fatigue behavior of conventionally cast MAR-M 200 AT 1000 deg C
The low cycle fatigue behavior of the nickel-based superalloy MAR-M 200 in conventionally cast form was studied at 1000 C. Continuous cycling tests, without hold times, were conducted with inelastic strain ranges of from 0.04 to 0.33 percent. Tests were also conducted which included a hold time at peak strain in either tension or compression. For the conditions studied, it was determined that imposition of hold times did not significantly affect the fatigue life. Also, for continuous cycling tests, increasing or decreasing the cycle frequency did not affect life. Metallographic analysis revealed that the most significant damage mechanism involved environmentally assisted intergranular crack initiation and propagation, regardless of the cycle type. Changes in the gamma morphology (rafting and rod formation) were observed, but did not significantly affect the failure
Low-density polybenzimidazole foams for thermal insulation and fire protection
Fire-resistant and nonsmoking foam can be prepared in desirable density range of 24 to 50 kg/cu m by controlled thermal crosslinking of polybenzimidazole prepolymer. Reproducible foams of specific density can be produced by controlling volative content and melting temperature of prepolymer
Decay Phase Cooling and Inferred Heating of M- and X-class Solar Flares
In this paper, the cooling of 72 M- and X-class flares is examined using
GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the
observed total cooling times are compared to the predictions of an analytical
0-D hydrodynamic model. It is found that the model does not fit the
observations well, but does provide a well defined lower limit on a flare's
total cooling time. The discrepancy between observations and the model is then
assumed to be primarily due to heating during the decay phase. The decay phase
heating necessary to account for the discrepancy is quantified and found be
~50% of the total thermally radiated energy as calculated with GOES. This decay
phase heating is found to scale with the observed peak thermal energy. It is
predicted that approximating the total thermal energy from the peak is
minimally affected by the decay phase heating in small flares. However, in the
most energetic flares the decay phase heating inferred from the model can be
several times greater than the peak thermal energy.Comment: Published in the Astrophysical Journal, 201
Risk factors for house-entry by malaria vectors in a rural town and satellite villages in The Gambia.
Background:
In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry.
Methods:
Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound.
Results:
106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the region. There were seven fold higher numbers of An. gambiae s.l. in the villages (geometric mean per trap night = 43.7, 95% confidence intervals, CIs = 39.5–48.4) than in Farafenni town (6.3, 5.7–7.2) and significant variation between residential blocks (p < 0.001). A negative binomial multivariate model performed equally well using unadjusted or adjusted trap data. Using the unadjusted data the presence of nuisance mosquitoes was reduced if the house was located in the town (odds ratio, OR = 0.11, 95% CIs = 0.09–0.13), the eaves were closed (OR = 0.71, 0.60–0.85), a horse was tethered near the house (OR = 0.77, 0.73–0.82), and churai, a local incense, was burned in the room at night (OR = 0.56, 0.47–0.66). Mosquito numbers increased per additional person in the house (OR = 1.04, 1.02–1.06) or trapping room (OR = 1.19, 1.13–1.25) and when the walls were made of mud blocks compared with concrete (OR = 1.44, 1.10–1.87).
Conclusion:
This study demonstrates that the risk of malaria transmission is greatest in rural areas, where large numbers of people sleep in houses made of mud blocks, where the eaves are open, horses are not tethered nearby and where churai is not burnt at night. These factors need to be considered in the design and analysis of intervention studies designed to reduce malaria transmission in The Gambia and other parts of sub-Saharan Africa
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