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PurposeSleep presents a bi-directional relationship with numerous health factors and is frequently altered in university students due to stress, higher workload or screen use. The regular practice of physical activity (PA) could be an alternative treatment to improve sleep quality. The aim of the study was to determine if the potential benefic effect of physical activity on sleep is sex dependent.MethodsBetween 2017 and 2019, 1696 students (20.3 ± 4.6 years old) from University of Littoral Côte d’Opale and of a couple of paramedical training sites participated in this study. They completed self-report questionnaires including Pittsburgh Sleep Quality Index (PSQI) and Global Physical Activity Questionnaire. Two groups were defined according to PA level (high vs. low subjective PA level). Two-way ANCOVA was performed to test between-group differences and to identify potential interaction between sex and physical activity level in PSQI score.ResultsWomen have a significantly higher PSQI score than men (6.43 ± 3.16 v 5.10 ± 2.92; p

Funding Information: The authors of PTB are grateful to Ingmar Müller who designed, set up and characterized the PQEDs calibrated by PTB and to Uwe Johannsen who set up and improved the cryogenic radiometer calibration facility of PTB. The research leading to these results has received funding from the European Community’s Seventh Framework Programme, ERA-NET Plus, under Grant Agreement No. 217257, from the European Metrology Research Programme (EMRP) Project SIB57 ‘New Primary Standards and Traceability for Radiometry’ and from the project 18SIB10 chipS.CALe (EMPIR). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The EMPIR programme is co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. EI acknowledges the support by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Publisher Copyright: © 2022 BIPM & IOP Publishing Ltd. The stability of induced junction silicon photodiodes used to construct the predictable quantum efficient detector (PQED) has been studied over a time period of a decade by measurements of its spectral responsivity against absolute cryogenic radiometers (CR) in two independent laboratories at CMI and PTB. PQEDs operated at room temperature show a long-term temporal stability within 150 ppm over a broad spectral range during a 10-year period, well within the range of the claimed measurement uncertainty values of the CRs. This long term stability fulfills one of the fundamental requirements to establish a new primary standard for the measurement of power of optical radiation.

Funding Information: This project (18SIB10 chipS.CALe) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. Authors of Aalto University acknowledge the support by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Publisher Copyright: © 2022 BIPM & IOP Publishing Ltd. We present a method to determine the internal quantum deficiency (IQD) of a predictable quantum efficient detector (PQED) based on measured photocurrent dependence on bias voltage and a 3D simulation model of charge carrier recombination losses. The simulation model of silicon photodiodes includes wafer doping concentration, fixed charge of SiO2 layer, bulk lifetime of charge carriers and surface recombination velocity as the fitted parameters. With only one set of physical photodiode defining parameters, the simulation shows excellent agreement with experimental data at power levels from 100 μW to 1000 μW with variation in illumination beam size. We could also predict the dependence of IQD on bias voltage at the wavelength of 476 nm using photodiode parameters determined independently at 647 nm wavelength. The fitted values of doping concentration and fixed charge extracted from the simulation model are in close agreement with the expected parameter values determined earlier. At bias voltages larger than 5 Vat the wavelength of 476 nm, the internal quantum efficiency of one of the tested PQEDs is measured to be 0.999 970 ± 0.000 027, where the relative expanded uncertainty of 0.000 027 is one of the lowest values ever achieved in spectral responsivity measurement of optical detectors.

Extreme lasers capable of short, high-energy pulses are probing the frontiers of science and advancing practical technology. The utility of such lasers increases with their average power delivery, which enables faster data acquisition, higher flux of laser-driven particle and radiation sources and more efficient material processing. However, the same extreme energies and electric field strengths of these lasers are currently preventing their direct and high accuracy measurement for these experimental applications. To overcome this limitation, we use the momentum of the laser pulses as a measurement proxy for their energy. When light reflects from an ideal mirror, its momentum is transferred to the mirror, but its energy is reflected. We demonstrate here a force-sensing mirror configuration to measure laser pulse energies up to 100 J/pulse (10 ns duration, 10 Hz repetition rate) from a kilowatt-level average power multi-slab laser operated at the HiLASE facility of the Czech Academy of Sciences. We combine a radiation-pressure power meter with a charge integrator photodiode to form what we refer to as a Radiation Pressure Energy Meter. To our knowledge, this is the first demonstration of a high-accuracy, non-absorbing, SI traceable primary standard measurement of both single and average pulse energies of a 1-kW-average-power pulsed laser source. With this, we demonstrate a practical method for in-situ calibration of the traditional thermal instruments (pyroelectric detectors) currently used for indirect measurements of energy and power of such extreme lasers.

La neutralité, en science comme ailleurs, est un vœu pieux, voire un leurre, à mieux comprendre, si ce n’est évaluer ou contrôler. Surtout, l’engagement sur un terrain d’études conduit à des surprises, voire à des déconvenues qui font le sel des ouvrages de N. Barley comme par exemple L’anthropologue en déroute (2001). Dans le cadre des approches sensibles en sciences humaines et sociales, les émotions ressenties par le corps, recueillies et partagées, avec plaisir ou déplaisir, ne sont plus considérées comme des perturbateurs de l’analyse mais comme des sésames d’accès à la compréhension humaine. Elles s’imposent à la chercheuse ou au chercheur, la/le surprennent ; elles deviennent des guides utiles, des opératrices d’inclinaisons, voire de bifurcations, dans la recherche scientifique. Longtemps délaissées, les émotions ne constituent plus un obstacle à la rationalité mais un échafaudage à l’avènement d’une orientation théorique spécifique plutôt qu’une autre, à une modification d’attitude sur le terrain, etc. Émotion et cognition sont, pour le pire et le meilleur, définitivement intriquées.

Une question de vocation ? « La sociologie est une sorte de vocation, un engagement intellectuel » : ce message m’a été transmis quand, jeune étudiant, je commençais mon parcours dans le domaine de la sociologie et des sciences politiques à l’université « Sapienza » de Rome. Dans le cadre de ma licence, les intervenants – souvent des maîtres de conférences et des professeurs des universités assez connus également en dehors de l’Académie – nous expliquaient que l’identité du sociologue se cons...

In recent years, there has been a growing interest in the measurements of the bidirectional reflectance distribution function (BRDF) in industry and research and development. However, there is currently no dedicated key comparison to demonstrate the scale conformity. To date, scale conformity has been proved only for classical in-plane geometries, in comparisons between different national metrology institutes (NMIs) and designated institutes (DIs). This study aims at expanding that with nonclassical geometries, including, for the first time, to the best of our knowledge, two out-of-plane geometries. A total of four NMIs and two DIs participated in a scale comparison of the BRDF measurements of three achromatic samples at 550 nm in five measurement geometries. The realization of the scale of BRDF is a well-understood procedure, as explained in this paper, but the comparison of the measured values presents slight inconsistencies in some geometries, most likely due to the underestimation of measurement uncertainties. This underestimation was revealed and indirectly quantified using the Mandel–Paule method, which provides the interlaboratory uncertainty. The results from the presented comparison allow the present state of the BRDF scale realization to be evaluated, not only for classical in-plane geometries, but also for out-of-plane geometries.

LED-based light sources have replaced massively traditional sources. The metrology traceability chains realised in leading European NMIs utilise the absolutely calibrated broadband radiometers (three-element silicon trap detectors) for calibrating primary photometers. Specific spectral properties of white LED allow to apply the trap detectors directly as new primary photometers. The unfiltered technique (Dӧnsberg at al., 2014) is used and the calibration of spectral irradiance responsivity is needed. We have a long experience in detector-based spectral irradiance responsivity calibrations declared by particular CMC’s published in BIPM KCDB. The aim of this work was to revise the uncertainty budget in order to reduce the measurement uncertainties for specific application of calibration of the trap-based unfiltered primary photometers UPP. The two calibration methods were used to analyse the occasional back-reflection effect of the UPP front aperture. The measurement was performed using our reference spectral responsivity facility in spectral range 350 nm – 900 nm.

Nel presente capitolo focalizzeremo l’attenzione sulle trasformazioni degli stili di vita di un campione di italiani durante il lockdown seguito alla pandemia da Covid-19.