256 research outputs found
Electronic phase diagram of LaBaSrCuO
We performed systematic measurements of magnetic susceptibility on single
crystals of LaBaSrCuO. The dependence of the
superconducting transition temperature on Sr-concentration demonstrates a
step-like pattern upon doping at {\it x}0.08 as the crystal structure
changes from low-temperature tetragonal (LTT) to low-temperature orthorhombic
(LTO) phase at low temperature. Upon cooling, an anomalous upturn in the
susceptibility was observed at the structural phase transition between the
LTT-LTO phases under the magnetic field parallel to {\it c}-axis.Comment: 6 pages, 4 figures, Proceeding paper of the Stripes2000 conference in
Roma, Ital
Preliminary assessment of the microwave landing system requirements for STOL operations
The results of an investigation made to assess the Microwave Landing System (MLS) Requirements for use by civil STOL aircraft are described. The principal MLS characteristics investigated in the report were signal accuracy and volume of coverage. The study utilized a nonlinear six-degree-of-freedom digital simulation of a De Havilland Buffalo C-8A aircraft. Fully automatic control of timed curve flight down to touchdown was simulated. Selected MLS accuracy and coverage parameters for the azimuth, primary elevation, flare evelation and DME signals were varied. The resulting STOL aircraft system performance in following a representative curved flight path was statistically determined. Coverage requirements for STOL aircraft operating in the terminal area environment were also investigated
Measurement by FIB on the ISS: Two Emissions of Solar Neutrons Detected?
A new type of solar neutron detector (FIB) was launched onboard the Space
Shuttle Endeavour on July 16, 2009, and it began collecting data at the
International Space Station (ISS) on August 25, 2009. This paper summarizes the
three years of observations obtained by the solar neutron detector FIB until
the end of July 2012. The solar neutron detector FIB can determine both the
energy and arrival direction of neutrons. We measured the energy spectra of
background neutrons over the SAA region and elsewhere, and found the typical
trigger rates to be 20 counts/sec and 0.22 counts/sec, respectively. It is
possible to identify solar neutrons to within a level of 0.028 counts/sec,
provided that directional information is applied. Solar neutrons were observed
in association with the M-class solar flares that occurred on March 7 (M3.7)
and June 7 (M2.5) of 2011. This marked the first time that neutrons were
observed in M-class solar flares. A possible interpretaion of the prodcution
process is provided.Comment: 36 pages, 16 figures, and 3 Tables; Advanced in Astronmy, 2012,
Special issue on Cosmic Ray Variablity:Century of Its Obseravtion
Solar wind dependence of the electron flux variation at geostationary orbit observed by ETS-V
In this study we have examined the relationship between the energetic electron flux at geostationary orbit and the solar wind speed. We have compared the electron flux ( >0.4MeV) observed by the Engineering Test Satellite V (ETS-V) with solar wind speed measurements in the OMNI data set obtained from the National Space Science Data Center (NSSDC). The tendency has been observed for the logarithm of the electron flux to be proportional to the solar wind speed at solar minimum, but scattered at solar maximum. We have found that during the main and recovery phases of magnetic storms occurring at solar minimum, the logarithm of the electron flux is roughly proportional to the solar wind speed. At solar maximum, however, there is no apparent correlation between both these parameters. Moreover, in quiet periods there is also no observable correlation at both solar minimum and maximum. The dependence of the electron flux at geostationary orbit on the solar wind speed is related to recurrent storms caused by high-speed solar wind streams
Single, dual and multiple respiratory virus infections and risk of hospitalization and mortality
Respiratory virus infections cause a significant number of hospitalization and deaths globally. This study investigated the association between single and multiple respiratory virus infections and risk of admission to a general ward, intensive care unit or death in patients aged 0–105 years (mean ± s.d. = 24·4 ± 24·1 years), from North West England, that were tested for respiratory virus infections between January 2007 and June 2012. The majority of infections were in children aged ⩽5 years. Dual or multiple infections occurred in 10·4% (1214/11 715) of patients, whereas single infection occurred in 89·6% (10 501/11 715). Rhinovirus was the most common co-infecting virus (occurring in 69·5%; 844/1214 of co-infections). In a multivariate logistic regression model, multiple infections were associated with an increased risk of admission to a general ward [odds ratio (OR) 1·43, 95% confidence interval (CI) 1·2–1·7, P < 0·0001]. On the other hand, patients with respiratory syncytial virus (RSV) and human parainfluenza virus types 1–3 (hPIV1–3), as a single infection, had a higher risk of being admitted to a general ward (OR 1·49, 95% CI 1·28–1·73, P < 0·0001 and OR 1·34, 95% CI 1·003–1·8, P = 0·05, respectively); admitted to an intensive-care unit or dying (OR 1·5, 95% CI 1·20–2·0, P = 0·001 and OR 1·60, 95% CI 1·02–2·40, P = 0·04, respectively). This result emphasizes the importance of RSV, hPIV and mixed infections and calls for research on vaccines, drugs and diagnostic tests targeting these respiratory viruses
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