7,094 research outputs found
Multiple input radio receiver Patent
Radio receiver with array of independently steerable antennas for deep space communicatio
Apparatus for aiding a pilot in avoiding a midair collision between aircraft
An apparatus for aiding a pilot in avoiding a midair collision between aircraft is described. A protected aircraft carries a transmitter, a transponder, a receiver, and a data processor; and an intruding cooperating aircraft carries a transponder. The transmitter of the protected aircraft continuously transmits a signal to the transponders of all intruding aircraft. The transponder of each of the intruding aircraft adds the altitude of the intruding aircraft to the signal and transmits it back to the receiver of the protected aircraft. The receiver selects only the signal from the most hazardous intruding aircraft and applies it to the data processor. From this selected signal the data processor determines the closing velocity between the protected and intruding aircraft, the range between the two aircraft, their altitude difference and the time to a possible collision
2010 Progress Report on the Economic Well-Being of Working-Age People with Disabilities
This progress report on the prevalence rate, employment, poverty, and household income of working-age people with disabilities (ages 21-64) uses data from the 2010 and earlier Current Population Surveys – Annual Social and Economic Supplement (CPS-ASES, a.k.a. Annual Demographic Survey, Income Supplement, and March CPS). The CPS is the only data set that provides continuously-defined yearly information on the working-age population with disabilities since 1981
Development of Collembolans after coversion towards organic farming
In Northern Germany, a diverse and complex experimental farm of the Federal Agricultural Research Centre (FAL) was set-up in 2001 covering all main aspects of organic farming. Previously, the 600 ha farm had been managed conventionally. Adjacent conventional farms were used as reference. The aim of this project was to study collembolans, microbial biomass and soil organic carbon in six organically farmed fields managed as a crop rotation of six different crops compared with an adjacent conventionally managed field. We hypothesised that the specific management in organic farming promotes soil biota. Soil samples were taken during the growing season in 2004. Collembolan abundances and microbial biomass were lower under organic management, but, generally, collembolan diversity was higher in organically farmed fields combined with a shifting in the dominance structure of the species. This result reveals that, even after three years, the soil biota is still changing with management conversion
2009 Progress Report on the Economic Well-Being of Working Age People with Disabilities
This progress report on the prevalence rate, employment, poverty, and household income of working-age people with disabilities (ages 21-64) uses data from the 2008 and earlier Current Population Surveys – Annual Social and Economic Supplement (CPS-ASES, a.k.a. Annual Demographic Survey, Income Supplement, and March CPS). The CPS is the only data set that provides continuously-defined yearly information on the working-age population with disabilities since 1981
Unloosing the Gordian knot of peroxisome formation
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordPeroxisome biogenesis is governed by molecular machineries, which are either unique to
peroxisomes or are partially shared with mitochondria. As peroxisomes have important
protective functions in the cell, modulation of their number is important for human health and
disease. Significant progress has been made towards our understanding of the mechanisms of
peroxisome formation, revealing a remarkable plasticity of the peroxisome biogenesis
pathway. Here we discuss most recent findings with particular focus on peroxisome
formation in mammalian cells.This work
was supported by the Biotechnology and Biological Sciences Research Council
(BB/K006231/1, BB/N01541X/1 to M.S.)
Large dimension Configuration Interaction calculations of positron binding to the group II atoms
The Configuration Interaction (CI) method is applied to the calculation of
the structures of a number of positron binding systems, including e+Be, e+Mg,
e+Ca and e+Sr. These calculations were carried out in orbital spaces containing
about 200 electron and 200 positron orbitals up to l = 12. Despite the very
large dimensions, the binding energy and annihilation rate converge slowly with
l, and the final values do contain an appreciable correction obtained by
extrapolating the calculation to the l to infinity limit. The binding energies
were 0.00317 hartree for e+Be, 0.0170 hartree for e+Mg, 0.0189 hartree for
e+Ca, and 0.0131 hartree for e+Sr.Comment: 13 pages, no figs, revtex format, Submitted to PhysRev
Airborne field strength monitoring
In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper
Relativistic coupled-cluster single-double calculations of positron-atom bound states
Relativistic coupled-cluster single-double approximation is used to calculate
positron-atom bound states. The method is tested on closed-shell atoms such as
Be, Mg, Ca, Zn, Cd, and Hg where a number of accurate calculations is
available. It is then used to calculate positron binding energies for a range
of open-shell transition metal atoms from Sc to Cu, from Y to Pd, and from Lu
to Pt. These systems possess Feshbach resonances, which can be used to search
for positron-atom binding experimentally through resonant annihilation or
scattering.Comment: submitted to Phys. Rev.
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