Monodisperse Dry Granular Flows on Inclined Planes : Role of Roughness

Recent studies have pointed out the importance of the basal friction on the dynamics of granular flows. We present experimental results on the influence of the roughness of the inclined plane on the dynamics of a monodisperse dry granular flow. We found experimentally that it exists a maximum of the friction for a given relative roughness. This maximum is shown to be independent of the angle of the slope. This behavior is observed for four planes with different bump sizes (given by the size of the beads glued on the plane) from 200 microns to 2 mm. The relative roughness corresponding to the maximum of the friction can be predicted with a geometrical model of stability of one single bead on the plane. The main parameters are the size of the bumps and the size of the flowing beads. In order to obtain a higher precision, the model also takes into account of the spacing between the bumps of the rough plane. Experimental results and model are in good agreement for all the planes we studied. Other parameters, like the sphericity of the beads, or irregularities in the thickness of the layer of glued particles, are shown to be of influence on the friction.Comment: 17 pages, 15 figures, submitted to EPJ

The future of the Protestant Church: Estimates for Austria and for the Provinces of Burgenland, Carinthia and Vienna

Secularization and migration have substantially affected the place of the Protestant Church in the Austrian society in the last decades. The number of members has been shrinking markedly from 447 thousand members in 1971 to 278 thousand in 2018. The trend is visible across all provinces, although the magnitude is stronger in Vienna where both disaffiliation and international migration are stronger: In the capital city, the Protestant population diminished from 126 thousand to 47 thousand over the 1971-2018 period. Using population projections of membership to the Protestant Church, we look at the potential future of affiliation to the Protestant Church in Austria, and in three provinces: Burgenland, Carinthia, and Vienna from 2018 to 2048, considering different paths of fertility and disaffiliation. We also look at the impact of different scenarios regarding the composition of international migration flows on affiliation to the Protestant Church. Our findings suggest that in the absence of compensatory flows, the Protestant Church will keep shrinking unless it manages to stop disaffiliation. The projections also show that migrants, especially within mobile Europe, are a potential source of members that is at present not properly contributing to membership in Austria. According to the TREND EUROPE scenario, which is – seen from today – the most likely scenario with a continuation of declining entries and increased exits, the Protestant population in Austria would still decline from 283 thousand in 2018 to 144 thousand in 2048 (-49%). At the level of the three provinces, the decline would be faster in Vienna (-42%, from 47 to 27 thousand) than in Burgenland (-26%, from 32 to 24 thousand) and Carinthia (-37%, from 48 to 30 thousand). According to this scenario, by 2048 the Protestant population would correspond to 1.5% of the total population of Austria(1.3% in Vienna, 7.3% in Burgenland and 5.4% in Carinthia). Other scenarios reflect the potential impact of different religious composition of future migrant flows, as well as changing disaffiliation patterns. Only under the LIFT scenario, which assumes a reduction in exits by 50% and more migrants enrolling to the Protestant Church, we see an end of the haemorrhage and even an increase in the number of Protestants in Vienna

Religious Affiliations in Austria at the Provincial Level: Estimates for Vorarlberg, 2001-2018

Religious affiliation is nowadays getting plenty of attention in Austria, in the public sphere with increased presence in the news and in the policy discourse. The aim of this study is to estimate the religious composition of the population of Vorarlberg in 2018, taking advantage of available data, such as census information and statistics on components of population change. The latest census that collected data on religion was implemented in 2001 and since then population counts have been relying on register data and did not collect data on the religious affiliation of the Austrian population. Therefore, to study changes in the religious composition of the population residing in Vorarlberg, it needs to be estimated using population projections following a methodology that was developed by Goujon et al. (2017) in a project to reconstruct (and project into the future) the population of Austria and Vienna in 2016. The reconstruction shows that Vorarlberg follows similar trends as those observed in Austria since 2001: 1) The share of Roman Catholics declines strongly, 2) there is a strong increase in the population with no religious affiliation, and 3) the share of Muslims has increased substantially which is the outcome of two main trends-fertility and migration. The study of the origin (country of birth) of Muslims residing in Vorarlberg in 2018 points at an increasing Austrian-born population, originating from parents or grandparents born predominantly in Turkey but also at a diversification as a result of the 2015 refugee crisis

Projections of adult skills and the effect of COVID-19

In this paper, we project Skills in Literacy Adjusted Mean Years of Schooling (SLAMYS) for the working age population in 45 countries and quinquennial time periods until 2050 according to various population scenarios. Moreover, we integrate the effect of school closures due to the COVID-19 pandemic on these projections. Adult skills are projected using the cohort components method. They can help in assessing the potential consequences of the recent trends for the adult population, particularly the workforce, whose skills are essential for the jobs contributing to economic growth and development outlooks. Our projections are novel as they take into account both the amount of schooling and quality of education and also consider the changes in adult skills through lifetime. Projections show that the adult skills gap between countries in the Global North and countries in the Global South will likely continue to exist by 2050, even under very optimistic assumptions–but may widen or narrow depending on the demographic development trajectories specific to each country. Moreover, the loss of learning due to school closures during the COVID-19 pandemic further exacerbates inequalities between countries. Particularly, in countries where schools have been closed for a prolonged period of time and the infrastructure for effective online schooling is lacking, the skills of cohorts who were in school during the pandemic have been severely affected. The fact that the duration of school closures has been longer in many low- and middle-income countries is a serious concern for achieving global human capital equality. The impact of the COVID-19 pandemic is projected to erase decades-long gains in adult skills for affected cohorts unless policies to mitigate learning loss are implemented immediately

Simulation and implementation of a piezoelectric sensor for harmonic in-situ strain monitoring

To monitor the strain in a multilayer steel/adhesive/ceramic beam structure, a 9-µmthick piezoelectric PVDF film is inserted in the adhesive joint. Two 2D finite element models of the structure with and without the film were developed using a sub-structuring procedure to reduce computational time and to refine the mesh in the thickness of the film. The models provide the harmonic displacement of the beam and the voltage across the film which is related to the strain. A prototype of the analyzed structure has been developed as well. Simulation and experimental analysis was performed and obtained results were compared. It was demonstrated that the influence of the presence of the film on the stress distribution is negligible, thus the implementation of an embedded PVDF film is a well-suited technique to monitor the strain transfer in a bonded assembl

PHARAO Laser Source Flight Model: Design and Performances

In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.Comment: Accepted for publication in Review of Scientific Instrument

Differences in fighting behaviour between male morphs of the stag beetle Lucanus cervus

Chez de nombreuses espèces d'insectes en général et de coléoptères en particulier, les mâles présentent des caractères sexuels secondaires exubérants, liés à la taille corporelle des animaux par des relations allométriques complexes, non linéaires. Ces dernières sont responsables d'un polymorphisme chez les mâles et suggèrent l'existence de pressions de sélection variables, fonctions de la taille adulte et soutenues par des stratégies comportementales dépendantes aussi de la taille. Dans ce travail, nous nous sommes intéressés aux relations existant entre les comportements agressifs et la taille corporelle du Lucane cerf-volant Lucanus cervus en développant une approche expérimentale. Cinq groupes de 10 mâles chacun ont été observés pendant 120 minutes et toutes les interactions agressives entre mâles ont été notées. La taille corporelle explique une large part de la hiérarchie linéaire détectée pendant la procédure expérimentale. Nos résultats suggèrent l'existence d'une taille corporelle seuil au delà de laquelle l'agressivité des mâles devient exacerbée. L'issue d'un combat entre mâles dépend fortement de la différence de taille entre les deux rivaux. Si l'agresseur est plus grand que l'agressé, le combat se solde très généralement en sa faveur alors que si l'agresseur est plus petit que l'agressé, l'issue du combat devient incertaine. Ainsi, au sein de notre population d'étude, la taille seuil d'agressivité correspond à la taille à partir de laquelle un animal présente une grande probabilité de rencontrer un animal plus petit que lui et de sortir vainqueur d'un combat.Non linear scaling relationships between extravagant characters and adult body size in numerous males of insects, particularly beetles, suggest that heterogeneous selection contexts shape differently the males according to their final body size and that behavioural tactics also depend on body size. We investigate the relationships between fighting behaviour and body size in the European Stag beetle Lucanus cervus using an experimental approach. In 5 experimental boxes, 10 different males were observed during 120 minutes and all male/male aggressive interactions were noted. Body size explained a large part of the linear hierarchy we detected during the experimental trials. Our results suggest the existence of a threshold body size determining the occurrence of exacerbated aggressive behaviour. The outcome of a male-male contest depends strongly on the body size difference between the two rivals. If the aggressor is the largest of the two males, he wins certainly the contest but the outcome of the contest becomes uncertain if the aggressor is the smallest of the two males. Therefore, in our population, the threshold body size of aggressivity corresponds to the size at which an animal has a high probability to fight with a smaller sufferer and then, to win the contest