27 research outputs found
First measurement of direct photoproduction on the proton
We report on the results of the first measurement of exclusive
meson photoproduction on protons for GeV and GeV. Data were collected with the CLAS detector at the Thomas
Jefferson National Accelerator Facility. The resonance was detected via its
decay in the channel by performing a partial wave analysis of the
reaction . Clear evidence of the meson
was found in the interference between and waves at GeV. The -wave differential cross section integrated in the mass range of
the was found to be a factor of 50 smaller than the cross section
for the meson. This is the first time the meson has been
measured in a photoproduction experiment
Deeply Virtual Compton Scattering Beam-Spin Asymmetries
The beam spin asymmetries in the hard exclusive electroproduction of photons
on the proton (ep -> epg) were measured over a wide kinematic range and with
high statistical accuracy. These asymmetries result from the interference of
the Bethe-Heitler process and of deeply virtual Compton scattering. Over the
whole kinematic range (x_B from 0.11 to 0.58, Q^2 from 1 to 4.8 GeV^2, -t from
0.09 to 1.8 GeV^2), the azimuthal dependence of the asymmetries is compatible
with expectations from leading-twist dominance, A = a*sin(phi)/[1+c*cos(phi)].
This extensive set of data can thus be used to constrain significantly the
generalized parton distributions of the nucleon in the valence quark sector.Comment: 1 tex file (6 pages), 4 (eps) figure
Analytical methods for determining metabolites of polycyclic aromatic hydrocarbon (PAH) pollutants in fish bile. A Review.
The determination of polycyclic aromatic hydrocarbon (PAH) metabolites in bile can serve as a tool for assessing environmental PAH exposure in fish. Biliary PAH metabolite levels can be measured using several analytical methods, including simple fluorescence assays (fixed fluorescence detection or synchronous fluorescence spectrometry); high-performance liquid chromatography with fluorescence detection (HPLC-F); gas chromatography–mass spectrometry (GC–MS) after deconjugation, extraction and derivatization of the bile sample, and finally by advanced liquid chromatography-tandem mass spectrometry (LC–MS/MS) and gas chromatography-tandem mass spectrometry (GC–MS/MS) methods. The method alternatives are highly different both with regard to their analytical performance towards different PAH metabolite structures as well as in general technical demands and their suitability for different monitoring strategies. In the present review, the state-of-the-art for these different analytical methods is presented and the advantages and limitations of each approach as well as aspects related to analytical quality control and inter-laboratory comparability of data and availability of certified reference materials are discussed.Financial support for different parts of the current work was provided by the EU – Standards, Measurements and Testing program (contract SMT4-CT98-2250), the Norwegian Research Council (projects 653879, 152449/720 and 153898/S40) and Total E&P Norge AS (TCP project). M.O. Sydnes (IRIS), G. Ylitalo and J. Stein (NOAA) are acknowledged for their valuable critical comments on the manuscript.Peer reviewe
Developing a large-scale dataset of flood fatalities for territories in the Euro-Mediterranean region, FFEM-DB
This data paper describes the multinational Database of Flood Fatalities from the Euro-Mediterranean region FFEM-DB that hosts data of 2,875 flood fatalities from 12 territories (nine of which represent entire countries) in Europe and the broader Mediterranean region from 1980 to 2020. The FFEM-DB database provides data on fatalities’ profiles, location, and contributing circumstances, allowing researchers and flood risk managers to explore demographic, behavioral, and situational factors, as well as environmental features of flood-related mortality. The standardized data collection and classification methodology enable comparison between regions beyond administrative boundaries. The FFEM-DB is expandable, regularly updated, publicly available, and with anonymized data. The key advantages of the FFEM-DB compared to existing datasets containing flood fatalities are its high level of detail, data accuracy, record completeness, and the large sample size from an extended area. © 2022, The Author(s)