Some possible interpretations from data of the CODALEMA experiment

The purpose of the CODALEMA experiment, installed at the Nan\c{c}ay Radio Observatory (France), is to study the radio-detection of ultra-high energy cosmic rays in the energy range of $10^{16}-10^{18} eV$. Distributed over an area of 0.25 km$^2$, the original device uses in coincidence an array of particle detectors and an array of short antennas, with a centralized acquisition. A new analysis of the observable in energy for radio is presented from this system, taking into account the geomagnetic effect. Since 2011, a new array of radio-detectors, consisting of 60 stand-alone and self-triggered stations, is being deployed over an area of 1.5 km$^2$ around the initial configuration. This new development leads to specific constraints to be discussed in term of recognition of cosmic rays and in term of analysis of wave-front.Comment: 13 pages, 12 figures Proceeding of the ARENA2012 conference, Erlangen, Germany To be published in AI

Results of the radio-detection experiment CODALEMA

International audienceMeasurements of the radio transients associated to Extensive Air Showers could provide a timely new effective method of detection of Ultra High Energy Cosmic Rays with interesting performances in term of techniques and of accessible observables. The CODALEMA experiment at the Radio Observatory of Nançay, France, explores this possibility using an array of broadband active dipole antennas triggered by an array of ground particle detectors. The implemented detection techniques, the methods of analysis developed and the principal results achieved during the 5 years of upgrading will be recalled. This cursory glance will provide an opportunity to point out some new issues and to suggest some future challenges in this domain

Le projet CODALEMA

National audienceThis chapter presents the methodology of the radio detection of cosmic ray extensive air showers developed for the codalema experiment. We illustrate the performances and results obtained in the first four years of operation of codalema

Influence of coating on the thermal resistance of a Ni-Based superalloy

In this paper, the influence of M-CrAlY polycrystalline coating on the thermal fatigue behavior of a Nickel-base superalloy has been investigated. A special device using a rotating bending machine and two thermal sources has been used to perform thermo-mechanical tests. The two thermal sources have been set to obtain temperature variations between 750 and 1120 °C in the central part of the specimens, with a frequency of 0.1 Hz. The results showed a deleterious effect of the coating on the fatigue resistance. Numerical simulations have been carried out on SAMCEF to determine the thermo-mechanical field of the so-tested specimens. Calculated thermo-mechanical cycles of critical sites are associated with microstructure evolution and damage by cracking observed on the specimens. Damage mechanisms related to the presence of coating are discussed

Using Salivary Biomarkers for Stress Assessment in Offshore Saturation Diving: A Pilot Study.

Health monitoring during offshore saturation diving is complicated due to restricted access to the divers, the desire to keep invasive procedures to a minimum, and limited opportunity for laboratory work onboard dive support vessels (DSV). In this pilot study, we examined whether measuring salivary biomarkrers in samples collected by the divers themselves might be a feasible approach to environmental stress assessment. Nine saturation divers were trained in the passive drool method for saliva collection and proceeded to collect samples at nine time points before, during, and after an offshore commercial saturation diving campaign. Samples collected within the hyperbaric living chambers were decompressed and stored frozen at -20°C onboard the DSV until they were shipped to land for analysis. Passive drool samples were collected without loss and assayed for a selection of salivary biomarkers: secretory immunoglobulin A (SIgA), C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukins IL-6, IL-8, IL-1β, as well as cortisol and alpha-amylase. During the bottom phase of the hyperbaric saturation, SIgA, CRP, TNF-α, IL-8 and IL-1β increased significantly, whereas IL-6, cortisol and alpha-amylase were unchanged. All markers returned to pre-dive levels after the divers were decompressed back to surface pressure. We conclude that salivary biomarker analysis may be a feasible approach to stress assessment in offshore saturation diving. The results of our pilot test are consonant with an activation of the sympathetic nervous system related to systemic inflammation during hyperbaric and hyperoxic saturation. [Abstract copyright: Copyright © 2021 Monnoyer, Lautridou, Deb, Hjelde and Eftedal.

Functional Profiling Reveals Altered Metabolic Activity in Divers’ Oral Microbiota During Commercial Heliox Saturation Diving

Background: The extreme environment in saturation diving affects all life forms, including the bacteria that reside on human skin and mucosa. The oral cavity alone is home to hundreds of different bacteria. In this study, we examined the metabolic activity of oral bacteria from healthy males during commercial heliox saturation diving. We focused on environmentally induced changes that might affect the divers’ health and fitness.Methods: We performed pathway abundance analysis using PICRUSt2, a bioinformatics software package that uses marker gene data to compute the metabolic activity of microbial communities. The analysis is based on 16S rRNA metagenomic data generated from the oral microbiota of 23 male divers before, during, and after 4weeks of commercial heliox saturation diving. Environmentally induced changes in bacterial metabolism were computed from differences in predicted pathway abundances at baseline before, versus during, and immediately after saturation diving.Results and Conclusion: The analysis predicted transient changes that were primarily associated with the survival and growth of bacteria in oxygenated environments. There was a relative increase in the abundance of aerobic metabolic pathways and a concomitant decrease in anaerobic metabolic pathways, primarily comprising of energy metabolism, oxidative stress responses, and adenosylcobalamin biosynthesis. Adenosylcobalamin is a bioactive form of vitamin B12 (vitB12), and a reduction in vitB12 biosynthesis may hypothetically affect the divers’ physiology. While host effects of oral bacterial vitamin metabolism are uncertain, this is a finding that concurs with the existing recommendations for vitB12 supplements as p

Hemoglobin during and following a 4-week commercial saturation dive to 200 meters

publishedVersio

Saint-Pierre-lès-Elbeuf – Le Mont Enot

Identifiant de l'opération archéologique : 76 640 001 Date de l'opération : 2005 (MH) Les investigations conduites sur le site de Saint-Pierre-lès-Elbeuf s’inscrivent dans le programme de recherche visant à une meilleure caractérisation des industries paléolithiques de Normandie. Ce projet avait motivé la reprise de la grande coupe de référence en 2004 pour un réexamen de la stratigraphie à la faveur des récents acquis chrono-stratigraphiques issus des travaux conduits sur le Nord de la Franc..