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Metal separations using aqueous biphasic partitioning systems
Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that the authors have studied are generated by combining an aqueous salt solution with an aqueous polymer solution. They have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. They have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this report they review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation
The On-orbit Calibrations for the Fermi Large Area Telescope
The Large Area Telescope (LAT) on--board the Fermi Gamma ray Space Telescope
began its on--orbit operations on June 23, 2008. Calibrations, defined in a
generic sense, correspond to synchronization of trigger signals, optimization
of delays for latching data, determination of detector thresholds, gains and
responses, evaluation of the perimeter of the South Atlantic Anomaly (SAA),
measurements of live time, of absolute time, and internal and spacecraft
boresight alignments. Here we describe on orbit calibration results obtained
using known astrophysical sources, galactic cosmic rays, and charge injection
into the front-end electronics of each detector. Instrument response functions
will be described in a separate publication. This paper demonstrates the
stability of calibrations and describes minor changes observed since launch.
These results have been used to calibrate the LAT datasets to be publicly
released in August 2009.Comment: 60 pages, 34 figures, submitted to Astroparticle Physic
Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era
We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society
Analytical extension of Finite Element solution for computing the nonlinear far field of ultrasonic waves scattered by a closed crack
Quantitative Assessment of Chronic Venous Insufficiency Using Duplex Ultrasound and Air Plethysmography
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data