4,649 research outputs found
Switching of Magnetic Moments of Nanoparticles by Surface Acoustic Waves
We report evidence of the magnetization reversal in nanoparticles by surface
acoustic waves (SAWs). The experimental system consists of isolated magnetite
nanoparticles dispersed on a piezoelectric substrate. Magnetic relaxation from
a saturated state becomes significantly enhanced in the presence of the SAW at
a constant temperature of the substrate. The dependence of the relaxation on
SAW power and frequency has been investigated. The effect is explained by the
effective ac magnetic field generated by the SAW in the nanoparticles.Comment: Accepted in Europhysics Letter
Comparison of two commercial ELISA kits and magnetic stirrer method for detection of Trichinella spp. in a pig slaughterhouse
ELISA represents a useful rapid method to detect the presence of specific antibodies on serum, plasma or meat juice collected at slaughter, however, false- and positive-results may occur depending on the sensitivity and specificity of the test. In this study we compare two commercial ELISA kits for the detection of specific antibodies against Trichinella spp. with respect to the gold standard method (artificial digestion) in a pig slaughterhouse. A total of 709 Iberian pigs belonging to 79 free-range herds were randomly selected and sampled (five to ten animals/herd) (Win Episcope 2.0; 95% confidence level, 8% accepted error)
Neutron star radius-To-mass ratio from partial accretion disk occultation as measured through fe kα line profiles
We present a new method to measure the radius-To-mass ratio (R/M) of weakly magnetic, disk-Accreting neutron stars by exploiting the occultation of parts of the inner disk by the star itself. This occultation imprints characteristic features on the X-ray line profile that are unique and are expected to be present in low-mass X-ray binary systems seen under inclinations higher than ∼65°. We analyze a Nuclear Spectroscopic Telescope Array observation of a good candidate system, 4U 1636-53, and find that X-ray spectra from current instrumentation are unlikely to single out the occultation features owing to insufficient signal-To-noise. Based on an extensive set of simulations we show that large-Area X-ray detectors of the future generation could measure R/M to ∼2 ÷ 3% precision over a range of inclinations. Such is the precision in radius determination required to derive tight constraints on the equation of state of ultradense matter and it represents the goal that other methods also aim to achieve in the future
Verbal Memory and IQ Predict Adaptive Behavior in Children and Adolescents with High-Functioning Autism Spectrum Disorders
Adaptive deficits are commonly found in high functioning autism spectrum disorders (HF-ASD) despite of cognitive potential. Most studies have focused on the relationships between adaptive behavior and intellectual quotient (IQ) and have used correlations to study relationships between them. Few studies have analyzed cognitive variables other than IQ as potential predictors of adaptive behavior in HF-ASD using regression methods. This study aimed to analyze the impact of several cognitive variables on adaptive behavior in a sample of children and adolescents with HF-ASD. METHODS: Sample included 16 child and adolescent boys with HF-ASD (age between 7-17 years). Cognitive assessment included measures of general intelligence, visual memory, verbal memory, working memory and problem solving/flexibility tests. Vineland Adaptive Behavior Scales (VABS) was used to evaluate adaptive behavior. To establish the predictive capacity of the cognitive variables for adaptive functioning, linear regression models were fitted for each adaptive domain using a stepwise method. RESULTS: Verbal memory and IQ emerged as the main independent predictors for VABS adaptive scores. The 41% of the variance in Communication was predicted by IQ. The 35% of the variance in Daily Living Skills was predicted by verbal memory. Almost half of the variance in Socialization was predicted by both, verbal memory and IQ (49%). No other cognitive functions were associated with adaptive scores. CONCLUSIONS: The results highlight the strong impact of IQ and verbal memory on adaptive behavior in HF-ASD patients. These findings could contribute to identify potential targets of intervention
Merging of Low-Mass Systems and the Origin of the Fundamental Plane
We present a new set of dissipationless N-body simulations to examine the
feasibility of creating bright ellipticals (following the Kormendy relation) by
hierarchically merging present-day early-type dwarf galaxies, and to study how
the encounter parameters affect the location of the end-product in the
plane. We investigate the merging of one-component
galaxies of both equal and different masses, the merging of two-component
galaxy models to explore the effect of dark halos on the final galaxy
characteristics, and the merging of ultracompact dwarf galaxies. We find that
the increase of with is attributable to an increase in the
initial orbital energy. The merger remnants shift down in the plane and fail to reach the KR. Thus, the KR is not reproducable by
mergers of dwarf early-type systems, rendering untenable the theory that
present-day dwarfs are responsible for even a small fraction of the present-day
ellipticals, unless a considerable amount of dissipation is invoked. However,
we do find that present-day dwarfs can be formed by the merger of ultra-compact
dwarfs.Comment: 10 pages, 8 figures. Accepted for publication in MNRA
Gold Binding by Native and Chemically Modified Hops Biomasses
Heavy metals from mining, smelting operations and other industrial processing facilities pollute
wastewaters worldwide. Extraction of metals from industrial effluents has been widely studied due to the
economic advantages and the relative ease of technical implementation. Consequently, the search for new
and improved methodologies for the recovery of gold has increased. In this particular research, the use of
cone hops biomass (Humulus lupulus) was investigated as a new option for gold recovery. The results
showed that the gold binding to native hops biomass was pH dependent from pH 2 to pH 6, with a maximum
percentage binding at pH 3. Time dependency studies demonstrated that Au(III) binding to native and
modified cone hops biomasses was found to be time independent at pH 2 while at pH 5, it was time
dependent. Capacity experiments demonstrated that at pH 2, esterified hops biomass bound 33.4 mg Au/g of
biomass, while native and hydrolyzed hops biomasses bound 28.2 and 12.0 mg Au/g of biomass,
respectively. However, at pH 5 the binding capacities were 38.9, 37.8 and 11.4 mg of Au per gram of native,
esterified and hydrolyzed hops biomasses, respectively
An alternative approach to the tomographic reconstruction of smooth refractive index distributions
Continuous, mathematically smooth Phase Objects with radial symmetry are reconstructed from cross sections of their refractive index distribution by a novel method, consisting of a linear combination of Gaussian basis functions, whose technical details are discussed. As an application example, this approach is used to get a fast and accurate estimation of the temperature distribution of an actual soldering tip
The QUIJOTE experiment: project overview and first results
QUIJOTE (Q-U-I JOint TEnerife) is a new polarimeter aimed to characterize the
polarization of the Cosmic Microwave Background and other Galactic and
extragalactic signals at medium and large angular scales in the frequency range
10-40 GHz. The multi-frequency (10-20~GHz) instrument, mounted on the first
QUIJOTE telescope, saw first light on November 2012 from the Teide Observatory
(2400~m a.s.l). During 2014 the second telescope has been installed at this
observatory. A second instrument at 30~GHz will be ready for commissioning at
this telescope during summer 2015, and a third additional instrument at 40~GHz
is now being developed. These instruments will have nominal sensitivities to
detect the B-mode polarization due to the primordial gravitational-wave
component if the tensor-to-scalar ratio is larger than r=0.05.Comment: To appear in "Highlights of Spanish Astrophysics VIII", Proceedings
of the XI Scientific Meeting of the Spanish Astronomical Society, Teruel,
Spain (2014
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
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