1,516 research outputs found
Fast radio bursts and their gamma-ray or radio afterglows as Kerr-Newman black hole binaries
Fast radio bursts (FRBs) are radio transients lasting only about a few
milliseconds. They seem to occur at cosmological distances. We propose that
these events can be originated in the collapse of the magnetosphere of
Kerr-Newman black holes (KNBHs). We show that the closed orbits of charged
particles in the magnetosphere of these objects are unstable. After examining
the dependencies on the specific charge of the particle and the spin and charge
of the KNBH, we conclude that the resulting timescale and radiation mechanism
fit well with the extant observations of FRBs. Furthermore, we argue that the
merger of a KNBH binary is one of the plausible central engines for potential
gamma-ray or radio afterglow following a certain FRBs, and can also account for
gravitational wave (GW) events like GW 150914. Our model leads to predictions
that can be tested by combined multi-wavelength electromagnetic and GW
observations.Comment: 6 pages, 4 figures, accepted for publication in Ap
Violin-Piano Sonata Recital: Won-Mo Kim, Violin; Tong-Il Han, Piano; February 25, 1973
Centennial East Recital HallSunday EveningFebruary 25, 19738:15 p.m
Carbon based coating on steel with improved electrical conductivity
Graphene and graphite were coated on steel plates by means of Electro
Phoresis Deposition (EPD) for electrical conductivity improvement. Thermal
treatment was used after EPD to improve the adhesion between the coating layer
and the steel substrate. The highest value of the electrical conductivity achieved
was 20 times higher than that of the steel substrate. The optimized EPD and
thermal treatment conditions were identified. The coating-steel interface and
surface structure suggested that good bonding between the coating and the
steel substrate was achieved
The capability of graphene on improving the electrical conductivity and anti-corrosion properties of Polyurethane coatings
Graphite and graphene particles were used to reinforce the electrical conductivity and anti-corrosion properties of polyurethane (PU) coatings. The effect of graphite and graphene were compared. Hybrid filler using carbon nanotube was adopted as well and the performance in electrical conductivity was much superior to single filler system. At the same filler loading, the electrical conductivity of hybrid filler system was significantly higher than single filler system (0.77 S/m at 5 wt% while single filler system was not conductive). The conductive mechanism was revealed. In terms of anti-corrosion properties, the coatings with low filler loading had better anti-corrosion properties. The resistance values obtained from EIS (Electrochemical Impedance Spectroscopy) and four point probe method were compared and
discussed
Fast radio bursts and their gamma-ray or radio afterglows as Kerr-Newman black hole binaries
Fast radio bursts (FRBs) are radio transients lasting only about a few milliseconds. They seem to occur at cosmological distances. We propose that these events can originate in the collapse of the magnetospheres of Kerr-Newman black holes (KNBHs). We show that the closed orbits of charged particles in the magnetospheres of these objects are unstable. After examining the dependencies on the specific charge of the particle and the spin and charge of the KNBH, we conclude that the resulting timescale and radiation mechanism fit well with extant observations of FRBs. Furthermore, we argue that the merger of a KNBH binary is a plausible central engine for the potential gamma-ray or radio afterglow following certain FRBs and can also account for gravitational wave (GW) events like GW 150914. Our model leads to predictions that can be tested by combined multi-wavelength electromagnetic and GW observations.Instituto Argentino de RadioastronomíaFacultad de Ciencias Astronómicas y Geofísica
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