192 research outputs found
Characterization and potential toxicity of asbestiform erionite from Gawler Downs, New Zealand
Erionite is the name for a zeolite mineral series originating from diagenesis or hydrothermal altera-
tion of volcanic rocks. The particular erionite “species” is based on the dominant extra-framework
cation, erionite-Ca, erionite-K, or erionite Na. Irrespective of the species, erionite can display a fibrous/
asbestiform morphology and has been linked with cases of malignant mesothelioma, a disease typi-
cally associated with asbestos exposure. Characterization of new discoveries of erionite is therefore
important to assess any potential exposure hazards. This study describes a new asbestiform erionite
from vesicles within the Upper Cretaceous Mt. Somers Volcanics Group (MSVG), Canterbury, New
Zealand. The erionite is within the Hinds River Dacite, the youngest unit within the MSVG at Gawler
Downs, ~100 km west of Christchurch, in the foothills of the Southern Alps. A multi-analytical ap-
proach was taken to analyze the sample which included micro-Raman spectroscopy, thermogravimetric
analysis, electron microscopy, electron microprobe analysis, and X-ray powder diffraction with the
Rietveld method. Results confirmed the mineral as fibrous erionite-K. The chemical composition of
the mineral is unique due to the presence of higher levels of Mg. While Fe was also identified, this was
due to smectite flakes occurring on the surface of the erionite fibers. According to the World Health
Organization (WHO) respirable mineral fiber definition, where length ≥5 μm, width ≤3 μm, and aspect
ratio (L/w) ≥3:1, the Gawler Downs erionite fibers are respirable, while the fibers themselves exceed
respirable thickness. In addition to morphology, a value for the potential toxicity model was computed
to be 2.28 for the Gawler Downs erionite. This is similar to those of other carcinogenic erionites from
Karain, Turkey (2.33), and Nevada, U.S.A. (2.28). Taken together, results indicate Gawler Downs
erionite represents an environmental hazard. Nevertheless, further investigation is required to determine
potential environmental exposure pathways by which erionite may become airborne and assess the
actual environmental risk in the Gawler Downs area
Kubernetes for the Deep Underground Neutrino Experiment Data Acquisition
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino experiment based in the USA which is expected to start taking data in 2029. DUNE aims to precisely measure neutrino oscillation parameters by detecting neutrinos from the LBNF beamline (Fermilab) at the Far Detector, 1,300 kilometres away, in South Dakota at the Sanford Underground Research Facility. The Far Detector will consist of four cryogenic Liquid Argon Time Projection Chamber detectors of 17 kT, each producing more than 1 TB/sec of data. The main requirements for the data acquisition system are the ability to run continuously for extended periods of time, with a 99% up-time requirement, and the functionality to record both beam neutrinos and low energy neutrinos from the explosion of a neighbouring supernova, should one occur during the lifetime of the experiment. The key challenges are the high data rates that the detectors generate and the deep underground environment, which places constraints on power and space. To overcome these challenges, DUNE plans to use a highly optimised C++ software suite and a server farm of about 110 nodes continuously running about two hundred multicore processes located close to the detector, 1.5 kilometres underground. Thirty nodes will be at the surface and will run around two hundred processes simultaneously. DUNE is studying the use of the Kubernetes framework to manage containerised workloads and take advantage of its resource definitions and high up-time services to run the DAQ system. Progress in deploying these systems at the CERN neutrino platform on the prototype DUNE experiments is reported
Search for heavy neutral lepton production in K+ decays
A search for heavy neutral lepton production in K + decays using a data sample collected with a minimum
bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10−7 to 10−6 level
are established on the elements of the extended neutrino mixing matrix |Ue4|
2 and |Uμ4|
2 for heavy
neutral lepton mass in the ranges 170–448 MeV/c2 and 250–373 MeV/c2, respectively. This improves on
the previous limits from HNL production searches over the whole mass range considered for |Ue4|2 and
above 300 MeV/c2 for |Uμ4|2
ECMO for COVID-19 patients in Europe and Israel
Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO
support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed
on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients
The FASER Detector
FASER, the ForwArd Search ExpeRiment, is an experiment dedicated to searching
for light, extremely weakly-interacting particles at CERN's Large Hadron
Collider (LHC). Such particles may be produced in the very forward direction of
the LHC's high-energy collisions and then decay to visible particles inside the
FASER detector, which is placed 480 m downstream of the ATLAS interaction
point, aligned with the beam collisions axis. FASER also includes a
sub-detector, FASER, designed to detect neutrinos produced in the LHC
collisions and to study their properties. In this paper, each component of the
FASER detector is described in detail, as well as the installation of the
experiment system and its commissioning using cosmic-rays collected in
September 2021 and during the LHC pilot beam test carried out in October 2021.
FASER will start taking LHC collision data in 2022, and will run throughout LHC
Run 3
Measurement of the very rare decay
The decay K+→π+νν¯
, with a very precisely predicted branching ratio of less than 10−10
,
is among the best processes to reveal indirect effects of new physics.
The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯
decay and to measure its branching ratio using a decay-in-flight technique.
NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model
for the K+→π+νν¯
decay by the analysis of the 2016 and 2017 data,
and providing the most precise measurement of the branching ratio to date
by the analysis of the 2018 data.
This measurement is also used to set limits on BR(K+→π+X
), where X
is a scalar
or pseudo-scalar particle.
The final result of the BR(K+→π+νν¯
) measurement and its interpretation in terms
of the K+→π+X
decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed
The Neutral Pion Form Factor at the NA62 Experiment
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient minimum bias trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A preliminary result of a new measurement of the electromagnetic
transition form factor slope of the neutral pion in the time-like momentum region from ∼ 1 million fully reconstructed (π0) Dalitz decays is presented
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