4,896,544 research outputs found
Search for gravitational waves from binary inspirals in S3 and S4 LIGO data
We report on a search for gravitational waves from the coalescence of compact
binaries during the third and fourth LIGO science runs. The search focused on
gravitational waves generated during the inspiral phase of the binary
evolution. In our analysis, we considered three categories of compact binary
systems, ordered by mass: (i) primordial black hole binaries with masses in the
range 0.35 M(sun) < m1, m2 < 1.0 M(sun), (ii) binary neutron stars with masses
in the range 1.0 M(sun) < m1, m2 < 3.0 M(sun), and (iii) binary black holes
with masses in the range 3.0 M(sun)< m1, m2 < m_(max) with the additional
constraint m1+ m2 < m_(max), where m_(max) was set to 40.0 M(sun) and 80.0
M(sun) in the third and fourth science runs, respectively. Although the
detectors could probe to distances as far as tens of Mpc, no gravitational-wave
signals were identified in the 1364 hours of data we analyzed. Assuming a
binary population with a Gaussian distribution around 0.75-0.75 M(sun), 1.4-1.4
M(sun), and 5.0-5.0 M(sun), we derived 90%-confidence upper limit rates of 4.9
yr^(-1) L10^(-1) for primordial black hole binaries, 1.2 yr^(-1) L10^(-1) for
binary neutron stars, and 0.5 yr^(-1) L10^(-1) for stellar mass binary black
holes, where L10 is 10^(10) times the blue light luminosity of the Sun.Comment: 12 pages, 11 figure
Potential of a sunflower seed by-product as animal fat replacer in healthier Frankfurters
Upcycled defatted sunflower seed flour (SUN), a by-product obtained from sunflower oil extraction, was used as an animal fat replacer to develop healthier frankfurters. For that end, animal fat was replaced (~50%) with water and 2% or 4% of SUN. Nutritional composition, technological, structural and sensorial properties were evaluated. SUN incorporation led to a significant increase in protein, minerals (magnesium, potassium, copper and manganese) and a decrease in fat content (~37% less than control with all animal fat). The incorporation of SUN in frankfurters promoted the presence of phenolic compounds. Increasing SUN addition lead to an increasingly (p < 0.05) darker frankfurter colour. Samples with SUN at 4% were firmer than the control according to TPA and sensory analysis results and showed the highest lipid disorder attributed to more lipid interactions in the meat matrix. SUN addition as an animal fat replacer in frankfurters is a feasible strategy to valorise sunflower oil by-products and obtain healthier frankfurters
Introducing a new technology to enhance community sustainability: An investigation of the possibilities of sun spots
The introduction of the Sun SPOT, Small Programmable Object Technology, developed by Sun Microsystems has been depicted as providing a revolutionary change in cyber physical interaction. Based on Sun Java Micro Edition (ME), this sensor technology has the potential to be used across a number of discipline areas to interface with systems, the environment and biological domains. This paper will outline the potential of Sun SPOTs to enhance community sustainability. An action based research project was carried out to investigate the potential uses of these technologies and develop a prototype system as a proof of concept. The research will compare Sun SPOTs with similar technologies, provide an assessment of the technology, and propose a number of possible implementations of the technology to enhance community sustainability
Is the Polar Region Different from the Quiet Region of the Sun?
Observations of the polar region of the Sun are critically important for
understanding the solar dynamo and the acceleration of solar wind. We carried
out precise magnetic observations on both the North polar region and the quiet
Sun at the East limb with the Spectro-Polarimeter of the Solar Optical
Telescope aboard Hinode to characterize the polar region with respect to the
quiet Sun. The average area and the total magnetic flux of the kG magnetic
concentrations in the polar region appear to be larger than those of the quiet
Sun. The magnetic field vectors classified as vertical in the quiet Sun have
symmetric histograms around zero in the strengths, showing balanced positive
and negative flux, while the histogram in the North polar region is clearly
asymmetric, showing a predominance of the negative polarity. The total magnetic
flux of the polar region is larger than that of the quiet Sun. In contrast, the
histogram of the horizontal magnetic fields is exactly the same between the
polar region and the quiet Sun. This is consistent with the idea that a local
dynamo process is responsible for the horizontal magnetic fields. A
high-resolution potential field extrapolation shows that the majority of
magnetic field lines from the kG-patches in the polar region are open with a
fanning-out structure very low in the atmosphere, while in the quiet Sun,
almost all the field lines are closed.Comment: Accepted for publication in AP
Accurate calculations of the WIMP halo around the Sun and prospects for its gamma-ray detection
Galactic weakly interacting massive particles (WIMPs) may scatter off solar
nuclei to orbits gravitationally bound to the Sun. Once bound, the WIMPs
continue to lose energy by repeated scatters in the Sun, eventually leading to
complete entrapment in the solar interior. While the density of the bound
population is highest at the center of the Sun, the only observable signature
of WIMP annihilations inside the Sun is neutrinos. It has been previously
suggested that although the density of WIMPs just outside the Sun is lower than
deep inside, gamma rays from WIMP annihilation just outside the surface of the
Sun, in the so called WIMP halo around the Sun, may be more easily detected. We
here revisit this problem using detailed Monte Carlo simulations and detailed
composition and structure information about the Sun to estimate the size of the
gamma-ray flux. Compared to earlier simpler estimates, we find that the
gamma-ray flux from WIMP annihilations in the solar WIMP halo would be
negligible; no current or planned detectors would be able to detect this flux.Comment: 18 pages, 7 figures, latex, updated to match published version
Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment
The sun blocks cosmic ray particles from outside the solar system, forming a
detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ
experiment in Tibet. Because the cosmic ray particles are positive charged, the
magnetic field between the sun and the earth deflects them from straight
trajectories and results in a shift of the shadow from the true location of the
sun. Here we show that the shift measures the intensity of the field which is
transported by the solar wind from the sun to the earth.Comment: 6 papges,3 figure
Detection of the temporal variation of the sun's cosmic ray shadow with the IceCube detector
We report on the observation of a deficit in the cosmic ray flux from the directions of the Moon and Sun with five years of data taken by the IceCube Neutrino Observatory. Between 2010 May and 2011 May the IceCube detector operated with 79 strings deployed in the glacial ice at the South Pole, and with 86 strings between 2011 May and 2015 May. A binned analysis is used to measure the relative deficit and significance of the cosmic ray shadows. Both the cosmic ray Moon and Sun shadows are detected with high statistical significance (> 10 sigma) for each year. The results for the Moon shadow are consistent with previous analyses and verify the stability of the IceCube detector over time. This work represents the first observation of the Sun shadow with the IceCube detector. We show that the cosmic ray shadow of the Sun varies with time. These results make it possible to study cosmic ray transport near the Sun with future data from IceCube
A sun sensor implemented with an asynchronous luminance vision sensor
A sun sensor implemented with a spiking pixel matrix is reported. It is the very first one based on an asynchronous event-based pixel array. A paradigm associated to classic digital sun sensors is solved with this approach. Only pixels illuminated by the sun light are readout. Hence, the output data flow is quite reduced. The computational load to resolve the sun position is quite low, comparing to prior sensors. Sensor's latency is in the order of milliseconds. The advantages over implementations with APS pixels are more reduced data flow, less latency, and higher dynamic range.Universidad de Cádiz PR2016-072Ministerio de Economía y Competitividad TEC2015-66878- C3-1-RJunta de Andalucía TIC 2012-2338Office of Naval Research (USA) N00014141035
- …
