411 research outputs found
Percolation-Modeling Comparison Between the Conductivities of Zinc-Graphene Quantum Dot Nanocomposite and Graphite during Extracellular Electron Transfer in Microbial Fuel Cell Electrodes
While promising as an energy production alternative through its sustainability and wastewater treatment utility, a microbial fuel cell is not widely used due to its low power output and high cost. The development of advanced electrode materials is currently being pursued to solve this problem. A zinc-graphene quantum dot nanocomposite was modeled using percolation theory as a prospective advanced electrode material. During extracellular electron transfer, the electrical conductivity properties of the material were studied through cellular percolation models, percolation probability functions, and electrical conductivity curves. These models were compared against those of the conventional graphite electrodes and the leading graphene electrodes. The nanocomposite was found to conduct at low probabilities of open sites and exhibit the highest electrical conductivity of the three materials for the longest duration across the interval. Based on the models, Zn-GQD was demonstrated to be an ideal MFC electrode material for its balance between the early onset of conduction and decently high electrical conductivity
Improved FIFRELIN de-excitation model for neutrino applications
The precise modeling of the de-excitation of Gd isotopes is of great interest
for experimental studies of neutrinos using Gd-loaded organic liquid
scintillators. The FIFRELIN code was recently used within the purposes of the
STEREO experiment for the modeling of the Gd de-excitation after neutron
capture in order to achieve a good control of the detection efficiency. In this
work, we report on the recent additions in the FIFRELIN de-excitation model
with the purpose of enhancing further the de-excitation description.
Experimental transition intensities from EGAF database are now included in the
FIFRELIN cascades, in order to improve the description of the higher energy
part of the spectrum. Furthermore, the angular correlations between {\gamma}
rays are now implemented in FIFRELIN, to account for the relative anisotropies
between them. In addition, conversion electrons are now treated more precisely
in the whole spectrum range, while the subsequent emission of X rays is also
accounted for. The impact of the aforementioned improvements in FIFRELIN is
tested by simulating neutron captures in various positions inside the STEREO
detector. A repository of up-to-date FIFRELIN simulations of the Gd isotopes is
made available for the community, with the possibility of expanding for other
isotopes which can be suitable for different applications.Comment: Corrected typos on author names on arXiv metadat
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The Double Chooz antineutrino detectors
This article describes the setup and performance of the near and far detectors in the Double Chooz experiment. The electron antineutrinos of the Chooz nuclear power plant were measured in two identically designed detectors with different average baselines of about 400 m and 1050 m from the two reactor cores. Over many years of data taking the neutrino signals were extracted from interactions in the detectors with the goal of measuring a fundamental parameter in the context of neutrino oscillation, the mixing angle θ13. The central part of the Double Chooz detectors was a main detector comprising four cylindrical volumes filled with organic liquids. From the inside towards the outside there were volumes containing gadolinium-loaded scintillator, gadolinium-free scintillator, a buffer oil and, optically separated, another liquid scintillator acting as veto system. Above this main detector an additional outer veto system using plastic scintillator strips was installed. The technologies developed in Double Chooz were inspiration for several other antineutrino detectors in the field. The detector design allowed implementation of efficient background rejection techniques including use of pulse shape information provided by the data acquisition system. The Double Chooz detectors featured remarkable stability, in particular for the detected photons, as well as high radiopurity of the detector components
Cannabidiol protects oligodendrocyte progenitor cells from inflammation-induced apoptosis by attenuating endoplasmic reticulum stress
Cannabidiol (CBD) is the most abundant cannabinoid in Cannabis sativa that has no psychoactive properties. CBD has been approved to treat inflammation, pain and spasticity associated with multiple sclerosis (MS), of which demyelination and oligodendrocyte loss are hallmarks. Thus, we investigated the protective effects of CBD against the damage to oligodendrocyte progenitor cells (OPCs) mediated by the immune system. Doses of 1 μM CBD protect OPCs from oxidative stress by decreasing the production of reactive oxygen species. CBD also protects OPCs from apoptosis induced by LPS/IFNγ through the decrease of caspase 3 induction via mechanisms that do not involve CB1, CB2, TRPV1 or PPARγ receptors. Tunicamycin-induced OPC death was attenuated by CBD, suggesting a role of endoplasmic reticulum (ER) stress in the mode of action of CBD. This protection against ER stress-induced apoptosis was associated with reduced phosphorylation of eiF2α, one of the initiators of the ER stress pathway. Indeed, CBD diminished the phosphorylation of PKR and eiF2α induced by LPS/IFNγ. The pro-survival effects of CBD in OPCs were accompanied by decreases in the expression of ER apoptotic effectors (CHOP, Bax and caspase 12), and increased expression of the anti-apoptotic Bcl-2. These findings suggest that attenuation of the ER stress pathway is involved in the ‘oligoprotective' effects of CBD during inflammation
The QKI-6 RNA Binding Protein Regulates Actin-interacting Protein-1 mRNA Stability during Oligodendrocyte Differentiation
We identify new mRNA targets for the QKI-6 RNA binding proteins using an unbiased approach. We show that AIP-1 mRNA is bound by QKI-6 within its 3′-UTR. This regulation is observed in oligodendrocytes and it is essential for oligodendrocyte process outgrowth
Novel event classification based on spectral analysis of scintillation waveforms in Double Chooz
Liquid scintillators are a common choice for neutrino physics experiments, but their capabilities to perform background rejection by scintillation pulse shape discrimination is generally limited in large detectors. This paper describes a novel approach for a pulse shape based event classification developed in the context of the Double Chooz reactor antineutrino experiment. Unlike previous implementations, this method uses the Fourier power spectra of the scintillation pulse shapes to obtain event-wise information. A classification variable built from spectral information was able to achieve an unprecedented performance, despite the lack of optimization at the detector design level. Several examples of event classification are provided, ranging from differentiation between the detector volumes and an efficient rejection of instrumental light noise, to some sensitivity to the particle type, such as stopping muons, ortho-positronium formation, alpha particles as well as electrons and positrons. In combination with other techniques the method is expected to allow for a versatile and more efficient background rejection in the future, especially if detector optimization is taken into account at the design level
Reverse genetics with a full-length infectious cDNA of severe acute respiratory syndrome coronavirus
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Yields and production rates of cosmogenic <sup>9</sup>Li and <sup>8</sup>He measured with the Double Chooz near and far detectors
The yields and production rates of the radioisotopes 9Li and 8He created by cosmic muon spallation on 12C, have been measured by the two detectors of the Double Chooz experiment. The identical detectors are located at separate sites and depths, which means that they are subject to different muon spectra. The near (far) detector has an overburden of ∼120 m.w.e. (∼300 m.w.e.) corresponding to a mean muon energy of 32.1 ± 2.0 GeV (63.7 ± 5.5 GeV). Comparing the data to a detailed simulation of the 9Li and 8He decays, the contribution of the 8He radioisotope at both detectors is found to be compatible with zero. The observed 9Li yields in the near and far detectors are 5.51 ± 0.51 and 7.90 ± 0.51, respectively, in units of 10−8μ−1g−1cm2. The shallow overburdens of the near and far detectors give a unique insight when combined with measurements by KamLAND and Borexino to give the first multi-experiment, data driven relationship between the 9Li yield and the mean muon energy according to the power law Y=Y0(〈Eμ〉/1GeV)α¯, giving α¯=0.72±0.06 and Y0 = (0.43 ± 0.11) × 10−8μ−1g−1cm2. This relationship gives future liquid scintillator based experiments the ability to predict their cosmogenic 9Li background rates
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