3,702 research outputs found
Second order statistics of NLOS indoor MIMO channels based on 5.2 GHz measurements
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Abell 1201: a Minor merger at second core passage
We present an analysis of the structures and dynamics of the merging cluster
Abell~1201, which has two sloshing cold fronts around a cooling core, and an
offset gas core approximately 500kpc northwest of the center. New Chandra and
XMM-Newton data reveal a region of enhanced brightness east of the offset core,
with breaks in surface brightness along its boundary to the north and east.
This is interpreted as a tail of gas stripped from the offset core. Gas in the
offset core and the tail is distinguished from other gas at the same distance
from the cluster center chiefly by having higher density, hence lower entropy.
In addition, the offset core shows marginally lower temperature and metallicity
than the surrounding area. The metallicity in the cool core is high and there
is an abrupt drop in metallicity across the southern cold front. We interpret
the observed properties of the system, including the placement of the cold
fronts, the offset core and its tail in terms of a simple merger scenario. The
offset core is the remnant of a merging subcluster, which first passed
pericenter southeast of the center of the primary cluster and is now close to
its second pericenter passage, moving at ~1000 km/s. Sloshing excited by the
merger gave rise to the two cold fronts and the disposition of the cold fronts
reveals that we view the merger from close to the plane of the orbit of the
offset core.Comment: accepted by Ap
Biochar from Pyrolysis of Biosolids for Nutrient Adsorption and Turfgrass Cultivation
At water resource recovery facilities, nutrient removal is often required and energy recovery is an ever-increasing goal. Pyrolysis may be a sustainable process for handling wastewater biosolids because energy can be recovered in the py-gas and py-oil. Additionally, the biochar produced has value as a soil conditioner. The objective of this work was to determine if biochar could be used to adsorb ammonia from biosolids filtrate and subsequently be applied as a soil conditioner to improve grass growth. The maximum carrying capacity of base modified biochar for NH3−N was 5.3 mg/g. Biochar containing adsorbed ammonium and potassium was applied to laboratory planters simulating golf course putting greens to cultivate Kentucky bluegrass. Planters that contained nutrient-laden biochar proliferated at a statistically higher rate than planters that contained biosolids, unmodified biochar, peat, or no additive. Nutrient-laden biochar performed as well as commercial inorganic fertilizer with no statistical difference in growth rates. Biochar from digested biosolids successfully immobilized NH3−N from wastewater and served as a beneficial soil amendment. This process offers a means to recover and recycle nutrients from water resource recovery facilities
Electroweak radiative corrections to the Higgs-boson production in association with -boson pair at colliders
We present the full electroweak radiative
corrections to the Higgs-boson production in association with -boson pair
at an electron-positron linear collider(LC) in the standard model. We analyze
the dependence of the full one-loop corrections on the Higgs-boson mass
and colliding energy . We find that the corrections significantly
suppress the Born cross section, and the electroweak
radiative corrections are generally between 1.0% and -15% in our chosen
parameter space, which should be taken into consideration in the future precise
experiments.Comment: 19 pages, 7 figures, to be published on Phys. ReV.
Kinetic power of quasars and statistical excess of MOJAVE superluminal motions
The MOJAVE survey contains 101 quasars with a total of 354 observed radio
components that are different from the radio cores, among which 95% move with
apparent projected superluminal velocities with respect to the core, and 45%
have projected velocities larger than 10c (with a maximum velocity 60c).
Doppler boosting effects are analyzed to determine the statistics of the
superluminal motions. We integrate over all possible values of the Lorentz
factor the values of the kinetic energy corresponding to each component. The
calculation of the mass in the ejection is carried out by assuming the minimum
energy state. This kinetic energy is multiplied by the frequency at which the
portions of the jet fluid identified as "blobs" are produced. Hence, we
estimate the average total power released by the quasars in the form of kinetic
energy in the long term on pc-scales.
RESULTS. A selection effect in which both the core and the blobs of the
quasar are affected by huge Doppler-boosting enhancement increases the
probability of finding a jet ejected within 10 degrees of the line of sight
>~40 times above what one would expect for a random distribution of ejection,
which explains the ratios of the very high projected velocities given above.
The average total kinetic power of each MOJAVE quasar should be very high to
obtain this distribution: ~7E47 erg/s. This amount is much higher than previous
estimates of kinetic power on kpc-scales based on the analysis of cavities in
X-ray gas or radio lobes in samples of objects of much lower radio luminosity
but similar black hole masses. The kinetic power is a significant portion of
the Eddington luminosity, on the order of the bolometric luminosity, and
proportional on average to square root of the radio luminosity, although this
correlation might be induced by Malmquist-like bias.Comment: Published in A&A; v2: minor changes to fit the published versio
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