An intercomparison for sampling and analysis of atmospheric mercury species was held in Tuscany, June 1998. Methods for sampling and analysis of total gaseous mercury (TGM), reactive gaseous mercury ...(RGM) and total particulate mercury (TPM) were used in parallel sampling over a period of 4 days. The results show that the different methods employed for TGM compared well whereas RGM and TPM showed a somewhat higher variability. Measurement results of RGM and TPM improved over the time period indicating that activities at the sampling site during set-up and initial sampling affected the results. Especially the TPM measurement results were affected. Additional parallel sampling was performed for two of the TPM methods under more controlled conditions which yielded more comparable results.
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The emission of inorganic divalent reactive gaseous mercury (RGM) from a mercury cell chlor-alkali plant (MCCAP) cell building and the impact on near field (100
km) dry deposition was investigated as ...part of a larger collaborative study between EPA, University of Michigan, Oak Ridge National Laboratory, Chlorine Institute, and Olin Corporation in February 2000. Measurements in the cell building roof vent showed that RGM constituted 2.1±0.7% (median±variance) of the concurrently measured elemental gaseous mercury (Hg
0). This relationship was used to calculate an estimated RGM emission rate from the cell building roof vent of 10.4
g
day
−1. The percentage of RGM/Hg
0 at ambient monitoring sites 350
m (1.5%) and 800
m (1.3%) away while being impacted by cell building emissions suggests the rapid deposition of RGM species. The observed 2% relative emission of RGM/Hg
0 was substantially lower than the 30% estimate utilized by EPA to model the impact of MCCAPs for the 1997 Mercury Report to Congress. However, the MCCAP was still found to present a significant impact on near field mercury atmospheric dry deposition. A Lagrangian transport and deposition modeling framework using only emissions from the MCCAP found the mean annualized dry deposition of mercury within a 10
km radius of the facility contributed the annual equivalent of 4.6
μg
m
−2. For comparison, the total annual wet mercury deposition measured at the Savannah River National Mercury Deposition Network sampling site ∼30
km away was 9.8
μg
m
−2.
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Source−receptor relationships for mercury (Hg) and other trace elements wet deposited in south Florida were investigated using daily event precipitation samples collected concurrently at 17 sites ...from August 6 to September 6, 1995. A multivariate receptor modeling approach found municipal waste incineration and oil combustion sources to account for 71 ± 8% of the Hg wet deposited at five Florida Everglades sites. A similar analysis of a year-long record of event samples (June 22, 1995−June 21, 1996) collected at Davie, FL, found 73 ± 6% of the Hg wet deposited to be accounted for by local anthropogenic sources. Receptor modeling results closely agreed with stack measurements made at local point sources during the study. An emissions reconciliation found that local medical waste incineration sources, which emitted Hg primarily in the reactive form (Hg(II)), could account for the Hg wet deposition left unexplained by the multivariate receptor model. The above findings suggest that emissions from local urban point sources have played the dominant role in the wet deposition of Hg to south Florida and the Everglades. Additional speciated Hg emissions data are needed not only in south Florida but also nationally and globally to reduce uncertainties in modeled Hg loadings to aquatic ecosystems.
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4.
Propagation of errors for matrix inversion Lefebvre, M.; Keeler, R.K.; Sobie, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2000, Volume:
451, Issue:
2
Journal Article
Peer reviewed
Open access
A formula is given for the propagation of errors during matrix inversion. An explicit calculation for a 2×2 matrix using both the formula and a Monte Carlo calculation are compared. A prescription is ...given to determine when a matrix with uncertain elements is sufficiently nonsingular for the calculation of the covariances of the inverted matrix elements to be reliable.
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A recent pilot study suggested that local anthropogenic sources may play an important role in the atmospheric deposition of mercury (Hg) in South Florida. To examine the potential impacts of these ...local anthropogenic sources of Hg, the South Florida Atmospheric Mercury Monitoring Study (SoFAMMS) was conducted from 6 August to 6 September 1995. The major goals of the SoFAMMS were to investigate potential source–receptor relationships between anthropogenic point-source emissions in south-east Florida (Dade and Broward Counties) and the atmospheric deposition of Hg and other trace elements across this region, which includes the Florida Everglades. As part of SoFAMMS, daily event precipitation samples were collected concurrently at 17 sites across the study domain during the 1-month period. All samples were analyzed for Hg and other trace elements. The volume-weighted mean concentrations of Hg measured at the 17 sites during the study ranged from 13 to 31 ng l
−1. While these monthly means indicated a significant site-to-site variation in Hg concentration, even greater differences between sites were observed on an event basis. Concentrations of Hg in individual daily event precipitation samples ranged from 5 to 113 ng l
−1. Similar spatial and temporal variations in precipitation concentrations were observed for other trace elements as well. These variations could not be accounted for by rainfall amounts alone. The spatial and temporal patterns observed suggest that local sources strongly influence atmospheric wet deposition across this region. Extensive elemental composition and meteorological precipitation data (including WSR-88D radar data from Miami, FL) were combined in an effort to look at the history of precipitation storm cells impacting the sampling sites and their spatial relationships to potential anthropogenic sources. Two sample periods are presented which demonstrate not only the impacts of local anthropogenic sources, but that these impacts fluctuate as a function of the mesoscale meteorological transport conditions. These preliminary findings indicate that local sources of Hg to South Florida and the Everglades may be more substantial than previous estimates.
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In response to the Coronavirus disease 2019 (COVID-19) global health pandemic, many employees transitioned to remote work, which included remote meetings. With this sudden shift, workers and the ...media began discussing videoconference fatigue, a potentially new phenomenon of feeling tired and exhausted attributed to a videoconference. In the present study, we examine the nature of videoconference fatigue, when this phenomenon occurs, and what videoconference characteristics are associated with fatigue using a mixed-methods approach. Thematic analysis of qualitative responses indicates that videoconference fatigue exists, often in near temporal proximity to the videoconference, and is affected by various videoconference characteristics. Quantitative data were collected each hour during five workdays from 55 employees who were working remotely because of the COVID-19 pandemic. Latent growth modeling results suggest that videoconferences at different times of the day are related to deviations in employee fatigue beyond what is expected based on typical fatigue trajectories. Results from multilevel modeling of 279 videoconference meetings indicate that turning off the microphone and having higher feelings of group belongingness are related to lower postvideoconference fatigue. Additional analyses suggest that higher levels of group belongingness are the most consistent protective factor against videoconference fatigue. Such findings have immediate practical implications for workers and organizations as they continue to navigate the still relatively new terrain of remote work.
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...because CD19 is a pan‐B cell marker, one side effect is normal B‐cell depletion. ...to try and restrict normal B‐cell depletion after CAR‐T cell administration, a recent study refined CD19 CAR‐T ...cells to recognize κ‐restricted cells, thereby excluding normal B‐cells from targeted destruction. ...the lentiviral StimvelisR recently received European Market Authorization to treat patients with adenosine deaminase‐SCID deficiency. Talimogene Laherparepvec has been approved for the treatment of advanced melanoma. ...Ad, one of the earliest vectors in the gene therapy field, may find a new role in cancer gene therapy along with other oncolytic viruses. ...although miRNA‐mediated gene regulation is seen in mammalian cells, the understanding of miR‐based diseases is at a fairly early stage. ...the modelling possible toxicities from such therapies are based more on theoretical concerns than on past experiences.
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A small test ion chamber has been constructed using 2,2,4,4 Tetramethylpentane as the ionizing liquid in direct contact with an array of lead plates used as the high voltage and ground planes. The ...transient response resulting from the passage of cosmic ray muons through the ion chamber was monitored for a period of 54 weeks to measure possible degradation of the signal due to contamination of the ionizing liquid that may have come from the lead plates. Over the first 17 weeks of the experiment, the loss of pulse height was measured to be less than 11% per year at 95 confidence. During the following 37 weeks, a more sensitive measurement was consistent with zero loss, or a limit of less than 2.9% per year at 95% confidence.
We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry ...breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurface that achieves a quality factor of ∼1300 at ∼10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (∼1 μm): a silicon-based implementation that achieves a quality factor of ∼350; and a gallium arsenide-based structure that achieves a quality factor of ∼600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. We envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.
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The psychometric soundness of measures has been a central concern of articles published in the Journal of Applied Psychology (JAP) since the inception of the journal. At the same time, it isn’t clear ...that investigators and reviewers prioritize psychometric soundness to a degree that would allow one to have sufficient confidence in conclusions regarding constructs. The purposes of the present article are to (a) examine current scale development and evaluation practices in JAP; (b) compare these practices to recommended practices, previous practices, and practices in other journals; and (c) use these comparisons to make recommendations for reviewers, editors, and investigators regarding the creation and evaluation of measures including Excel-based calculators for various indices. Finally, given that model complexity appears to have increased the need for short scales, we offer a user-friendly R Shiny app (https://orgscience.uncc.edu/about-us/resources) that identifies the subset of items that maximize a variety of psychometric criteria rather than merely maximizing alpha. (PsycInfo Database Record (c) 2022 APA, all rights reserved) (Source: journal abstract)
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