9,755 research outputs found
Aerodynamic data on a large semispan tilting wing with 0.5-diameter chord, double-slotted flap, and both left-hand and right-hand rotation of a single propeller
Longitudinal aerodynamic data on large-scale semispan V/STOL tilt-wing configuration having single propeller with left and right hand rotatio
Time reversal in thermoacoustic tomography - an error estimate
The time reversal method in thermoacoustic tomography is used for
approximating the initial pressure inside a biological object using
measurements of the pressure wave made on a surface surrounding the object.
This article presents error estimates for the time reversal method in the cases
of variable, non-trapping sound speeds.Comment: 16 pages, 6 figures, expanded "Remarks and Conclusions" section,
added one figure, added reference
Solution to the twin image problem in holography
While the invention of holography by Dennis Gabor truly constitutes an
ingenious concept, it has ever since been troubled by the so called twin image
problem limiting the information that can be obtained from a holographic
record. Due to symmetry reasons there are always two images appearing in the
reconstruction process. Thus, the reconstructed object is obscured by its
unwanted out of focus twin image. Especially for emission electron as well as
for x- and gamma-ray holography, where the source-object distances are small,
the reconstructed images of atoms are very close to their twin images from
which they can hardly be distinguished. In some particular instances only,
experimental efforts could remove the twin images. More recently, numerical
methods to diminish the effect of the twin image have been proposed but are
limited to purely absorbing objects failing to account for phase shifts caused
by the object. Here we show a universal method to reconstruct a hologram
completely free of twin images disturbance while no assumptions about the
object need to be imposed. Both, amplitude and true phase distributions are
retrieved without distortion
The health of the poor: Women living in informal settlements
Objectives: A large share of the urban population in developing countries lives in informal settlements or “slums” today. This study investigates the association between slum residence and health among adult Ghanaian women residing in the Accra Metropolitan Area.Methods: Health data collected as part of the Women’s Health Study of Accra round II (WHSA-II) was combined with data from the Household and Welfare Study of Accra (HAWS) to compare the health of female slum dwellers to the health of female non-slum dwellers living in the Accra Metropolitan Area. Group means were calculated and multivariate linear regression models were estimated to compare eight domains ofhealth as measured by the short-form 36 (SF-36) questionnaire.Results: Women living in informal settlements were found to display consistently better health. Conditional on all observable characteristics, women living in informal settlements scored higher on all self-reportedhealth outcomes than women living in non-slum areas. The differences appear largest for general health as well as for the physical role functioning domains, and appear smallest for the social role functioning and bodily pain domains.Conclusions: The results presented suggest that slum residence does not have a negative effect on self-reported health among women in Accra. Three factors may contribute to the generally positive association betweenslum residence and observed outcomes: i) selfselection of individuals with strong health into informal settlements and an accordingly small impact ofenvironmental factors on health ii) self-selection of more driven and ambitious individuals into slum neighborhoods who may have a generally more positive view of their health and iii) the geographic placement ofslum neighborhoods in central neighborhoods with relatively easy access to health facilities
The application of eye-tracking in music research
Though eye-tracking is typically a methodology applied in the visual research domain, recent studies suggest its relevance in the context of music research. There exists a community of researchers interested in this kind of research from varied disciplinary backgrounds scattered across the globe. Therefore, in August 2017, an international conference was held at the Max Planck Institute for Empirical Aesthetics in Frankfurt, Germany, to bring this research community together. The conference was dedicated to the topic of music and eye-tracking, asking the question: what do eye movements, pupil dilation, and blinking activity tell us about musical processing? This special issue is constituted of top-scoring research from the conference and spans a range of music-related topics. From tracking the gaze of performers in musical trios to basic research on how eye movements are affected by background music, the contents of this special issue highlight a variety of experimental approaches and possible applications of eye-tracking in music research
Electron-phonon coupling in 122 Fe pnictides analyzed by femtosecond time-resolved photoemission
Based on results from femtosecond time-resolved photoemission, we compare
three different methods for determination of the electron-phonon coupling
constant {\lambda} in Eu and Ba-based 122 FeAs compounds. We find good
agreement between all three methods, which reveal a small {\lambda} < 0.2. This
makes simple electron-phonon mediated superconductivity unlikely in these
compounds.Comment: 11 pages, 3 figure
Cavity QED with separate photon storage and qubit readout modes
We present the realization of a cavity quantum electrodynamics setup in which
photons of strongly different lifetimes are engineered in different harmonic
modes of the same cavity. We achieve this in a superconducting transmission
line resonator with superconducting qubits coupled to the different modes. One
cavity mode is strongly coupled to a detection line for qubit state readout,
while a second long lifetime mode is used for photon storage and coherent
quantum operations. We demonstrate sideband based measurement of photon
coherence, generation of n photon Fock states and the scaling of the sideband
Rabi frequency with the square root of n using a scheme that may be extended to
realize sideband based two-qubit logic gates.Comment: 4 pages, 5 figures, version with high resolution figures available at
http://qudev.ethz.ch/content/science/PubsPapers.htm
Momentum dependent ultrafast electron dynamics in antiferromagnetic EuFe2As2
Employing the momentum-sensitivity of time- and angle-resolved photoemission
spectroscopy we demonstrate the analysis of ultrafast single- and many-particle
dynamics in antiferromagnetic EuFe2As2. Their separation is based on a
temperature-dependent difference of photo-excited hole and electron relaxation
times probing the single particle band and the spin density wave gap,
respectively. Reformation of the magnetic order occurs at 800 fs, which is four
times slower compared to electron-phonon equilibration due to a smaller
spin-dependent relaxation phase space
A complex relationship between immunity and metabolism in Drosophila diet-induced insulin resistance
- …