Search results for " magnitude"
showing 10 items of 407 documents
Constraints on Cosmic Strings Using Data from the Third Advanced LIGO–Virgo Observing Run
2021
We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 data set. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks and, for the first time, kink-kink collisions.cA template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension, $G\mu$, as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models.cAdditionally, we develop and test a third model which interpolat…
Influence of impurity scattering on Drude response in heavy-fermion UPd2Al3
2010
The frequency-dependent conductivity of heavy-fermion metals can often be described within the picture of the Drude response: the transport relaxation rate is the only relevant frequency scale and, furthermore, reduced by orders of magnitude compared to normal metals. While the relaxation-time enhancement corresponds to the effective-mass enhancement in these materials, i.e. a fundamental material characteristic, the absolute value of the relaxation time depends on the details of the relevant scattering processes. Here we discuss the influence of impurity scattering on the Drude response of the heavy fermions in UPd2Al3 by comparing different thin film samples.
Long-term X-ray variability of the microquasar system LS 5039/RX J1826.2−1450
2003
We report on the results of the spectral and timing analysis of a BeppoSAX observation of the microquasar system LS 5039/RX J1826.2-1450. The source was found in a low-flux state with Fx(1-10 keV)= 4.7 x 10^{-12} erg cm^{-2} s^{-1}, which represents almost one order of magnitude lower than a previous RXTE observation 2.5 years before. The 0.1--10 keV spectrum is described by an absorbed power-law continuum with photon-number spectral index Gamma=1.8+-0.2 and hydrogen column density of NH=1.0^{+0.4}_{-0.3} x 10^{22} cm^{-2}. According to the orbital parameters of the system the BeppoSAX observation covers the time of an X-ray eclipse should one occur. However, the 1.6-10 keV light curve does…
A field assessment of the Simplified Falling Head technique to measure the saturated soil hydraulic conductivity
2012
Abstract The Simplified Falling Head (SFH) technique to measure field saturated soil hydraulic conductivity, Kfs, has received little testing or comparison with other techniques. Different experiments were carried out to i) determine the effect of ring size on the measured conductivity; ii) compare the SFH and Pressure Infiltrometer (PI) techniques in a clay loam soil; and iii) evaluate the approach used in the SFH methodology to estimate the α* parameter. Sampling a relatively large number of sites allowed to detect statistically significant relationships between the Kfs values obtained with rings differing in diameter (0.15 and 0.30 m, respectively). The ring size effect was substantial (…
Gold Nanoparticle Growth Monitored in situ Using a Novel Fast Optical Single-Particle Spectroscopy Method
2007
Size- and shape-dependent optical properties of gold nanorods allow monitoring their growth using a novel fast single-particle spectroscopy (fastSPS) method. FastSPS uses a spatially addressable electronic shutter based on a liquid crystal device to investigate particles randomly deposited on a substrate, orders of magnitude faster than other techniques. We use fastSPS to observe nanoparticle growth in situ on a single-particle level and extract quantitative data on nanoparticle growth.
Zr- Hf Fractionation During Water-Rock Interaction
2017
International audience; Zr and Hf are two elements having same ionic charge and similar ionic size at a given coordination number. Despite the Zr/Hf ratio is considered to be quite constant in meteorites and lithospheric rocks, seawaters collected from the surface down to varying depths of several Pacific Ocean stations reveal that the Zr/Hf ratio increases by one order of magnitude. Very recent studies have shown that, in both ground waters and lake waters, the Zr/Hf ratio is either higher or lower compared to the interacting minerals displaying a large variability in the distribution of these twin elements. In this communication the possible processes responsible for such a large fraction…
Cavity optomechanics mediated by a quantum two-level system
2015
Coupling electromagnetic waves in a cavity and mechanical vibrations via the radiation pressure of photons is a promising platform for investigations of quantum–mechanical properties of motion. A drawback is that the effect of one photon tends to be tiny, and hence one of the pressing challenges is to substantially increase the interaction strength. A novel scenario is to introduce into the setup a quantum two-level system (qubit), which, besides strengthening the coupling, allows for rich physics via strongly enhanced nonlinearities. Here we present a design of cavity optomechanics in the microwave frequency regime involving a Josephson junction qubit. We demonstrate boosting of the radiat…
Search for Spin-Dependent Short-Range Interaction with an 3He/129Xe Clock Comparison Experiment
2016
We performed an experiment to search for a new spin-dependent P- and T-violating nucleon–nucleon interaction [Formula: see text] which is mediated by light pseudoscalar bosons such as axions or axionlike particles. This interaction causes a shift [Formula: see text] in the precession frequency of nuclear spin polarized gases in the presence of an unpolarized mass. In order to measure this frequency shift a 3He/[Formula: see text]Xe comagnetometer was used which is based on the detection of free precession of 3He and [Formula: see text]Xe nuclear spins using SQUIDs as detectors. For the upper limit of [Formula: see text] we obtained 7.1[Formula: see text]nHz. With this value, an upper limit…
Comparative LA-ICP-IDMS determinations of trace elements in powdered samples using laser ablation systems with low and high ablation rates
2004
The results of laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) with a special laser ablation system with high ablation rates (LINA-Spark-Atomiser), which was constructed for bulk analyses of solid samples, are compared with those obtained by one of the commonly used LA systems (UP213). Using different reference materials for validation it was demonstrated that the accuracy of LA-ICP-IDMS determinations of elements like Fe, Cu, Pb, and Zn by both systems is comparable in the concentration range of 10−2–10−6 g g−1, but the LINA-Spark-Atomiser also provides accurate results in the sub-μg g−1 range. IDMS enables accurate calibration of LA-ICP-MS determ…
Triple resonant four-wave mixing: A microwatt continuous-wave laser source in the vacuum ultraviolet region at 120 nm
2012
We present a vacuum ultraviolet laser source by four-wave mixing in mercury vapour based on solid-state laser systems. Maximum powers of 6μW were achieved with an increase of four orders of magnitude in efficiency.