We present two results of a search for MeV-scale neutrino and anti-neutrino events correlated with gravitational wave events/candidates and large solar flares with KamLAND. The KamLAND detector is a ...large-volume neutrino detector using liquid scintillator, which is located at 1 km underground under the top of Mt. Ikenoyama in Kamioka, Japan. KamLAND has multiple reaction channels to detect neutrinos. Electron antineutrino can be detected via inverse-beta decay with 1.8 MeV neutrino energy threshold. All flavors of neutrinos can be detected via neutrino-electron scattering without neutrino energy threshold. KamLAND has continued the neutrino observation since 2002 March. We use the data set of 60 gravitational waves provided by the LIGO/Virgo collaboration during their second and third observing runs and search for coincident electron antineutrino events in KamLAND. We find no significant coincident signals within a ±500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 108–1013 cm-2 for neutrino energies of 1.8–111 MeV. For a solar-flare neutrino search at KamLAND, we determine the timing window using the solar X-ray data set provided by the GOES satellite series from 2002 to 2019 and search for the excess of coincident event rate on the all-flavor neutrinos. We find no significant event rate excess in the flare time windows and get 90% C.L. upper limits on the fluence of neutrinos of all flavors (electron anti-neutrinos) between 1010–1013 cm-2 (108–1013 cm-2) for neutrino energies in the energy range of 0.4–35 MeV.
Some values of the coincidence search in Section 3 were not correct in the published article. The time differences of the closest event to GW150915, GW151226, and LVT151012 are 1.9 h, 5.7 h, and 1017 ...s, respectively. The energies of the closest event are 2.07 MeV, 2.67 MeV, and 1.41 MeV, respectively. Figures 1, 2, and 3 were not correct in the published article. The corrected figures are provided here.
We describe a compact, ultra-clean device used to deploy radioactive sources along the vertical axis of the KamLAND liquid-scintillator neutrino detector for purposes of calibration. The device ...worked by paying out and reeling in precise lengths of a hanging, small-gauge wire rope (cable); an assortment of interchangeable radioactive sources could be attached to a weight at the end of the cable. All components exposed to the radiopure liquid scintillator were made of chemically compatible UHV-cleaned materials, primarily stainless steel, in order to avoid contaminating or degrading the scintillator. To prevent radon intrusion, the apparatus was enclosed in a hermetically sealed housing inside a glove box, and both volumes were regularly flushed with purified nitrogen gas. An infrared camera attached to the side of the housing permitted real-time visual monitoring of the cable׳s motion, and the system was controlled via a graphical user interface.
Advancements in measurement and modeling capabilities are providing unprecedented access to estimates of chemical exposure and bioactivity. With this influx of new data, there is a need for ...frameworks that help organize and disseminate information on chemical hazard and exposure in a manner that is accessible and transparent. A case study approach was used to demonstrate integration of the Adverse Outcome Pathway (AOP) and Aggregate Exposure Pathway (AEP) frameworks to support cumulative risk assessment of co-exposure to two phthalate esters that are ubiquitous in the environment and that are associated with disruption of male sexual development in the rat: di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP). A putative AOP was developed to guide selection of an in vitro assay for derivation of bioactivity values for DEHP and DnBP and their metabolites. AEPs for DEHP and DnBP were used to extract key exposure data as inputs for a physiologically based pharmacokinetic (PBPK) model to predict internal metabolite concentrations. These metabolite concentrations were then combined using in vitro-based relative potency factors for comparison with an internal dose metric, resulting in an estimated margin of safety of ~13,000. This case study provides an adaptable workflow for integrating exposure and toxicity data by coupling AEP and AOP frameworks and using in vitro and in silico methodologies for cumulative risk assessment.
•Major exposure routes extracted from an AEP were used to estimate exposures to DEHP and DnBP.•A new AOP was developed for disruption of male development through reduced testosterone production via inhibition of c-PLA2.•A margin of safety was determined for aggregate exposures to DEHP and DnBP.•These AEP-AOP frameworks will inform decisions in cumulative risk assessment.
COHERENT Experiment: current status Akimov, D; Albert, J B; Awe, C ...
Journal of physics. Conference series,
01/2017, Letnik:
798, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The COHERENT Collaboration is realizing a long term neutrino physics research program. The main goals of the program are to detect and study elastic neutrino-nucleus scattering (CE NS). This process ...is predicted by Standard Model but it has never been observed experimentally because of the very low energy of the recoil nucleus. COHERENT is using different detector technologies: CsINa and NaI scintillator crystals, a single-phase liquid Ar and a Ge detectors. The placement of all the detector setups is in the basement of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The current status of the COHERENT experimental program is presented.
The Threshold of Toxicological Concern (TTC) is a risk assessment tool for evaluating low-level exposure to chemicals with limited toxicological data. A next step in the ongoing development of TTC is ...to extend this concept further so that it can be applied to internal exposures. This refinement of TTC based on plasma concentrations, referred to as internal TTC (iTTC), attempts to convert the chemical-specific external NOAELs (in mg/kg/day) in the TTC database to an estimated internal exposure. A multi-stakeholder collaboration formed, with the aim of establishing an iTTC suitable for human safety risk assessment. Here, we discuss the advances and future directions for the iTTC project, including: (1) results from the systematic literature search for metabolism and pharmacokinetic data for the 1,251 chemicals in the iTTC database; (2) selection of ~350 chemicals that will be included in the final iTTC; (3) an overview of the
caco-2 and
hepatic metabolism studies currently being generated for the iTTC chemicals; (4) demonstrate how PBPK modeling is being utilized to convert a chemical-specific external NOAEL to an internal exposure; (5) perspective on the next steps in the iTTC project.
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