The Atmosphere Explorer and the shuttle glow

Recent analyses of the Atmosphere Explorer data are discussed in which it is demonstrated that the satellite glows have two components, one at high altitudes which is consistent with excitation in single collisions of atmospheric oxygen atoms with the vehicle surface and the other at low altitudes which is consistent with double collisions of nitrogen molecules. Contrary to an earlier suggestion, the low-altitude data are not consistent with collisions of oxygen molecules. The separation of the two components strengthens the conclusion that the high-altitude glow arises from vibrationally excited OH molecules produced by a formation mechanism that is different from that leading to the normal atmospheric OH airglow. The spectrum is consistent with association of oxygen and hydrogen atoms at sites on the surface into the vibrational levels of OH. The low-altitude glow is consistent with the green mechanism but there are difficulties with it. The shuttle glows are different and have the spectral appearance of emission from NO2. The characteristics of the shuttle glows and the satellite glows will be contrasted and a tentative resolution of the differences in the Atmosphere Explorer and shuttle glows will be offered

I Am My Identity Kit : using Artifact Data in Research on Identity

Este texto se presentó como comunicación al II Congreso Internacional de Etnografía y Educación: Migraciones y Ciudadanías. Universidad Autónoma de Barcelona, Barcelona, 5-8 Septiembre 2008.This presentation addresses how to collect and analyze artifacts in ethnographic and qualitative research, and the value of using artifacts in research which seeks to describe and interpret the identities that research participants construct. We believe that artifacts can be very useful in such research, because they tell us about the every day, taken-for-granted cultural meanings that people give to their surroundings, the things they make, their tools, toys, clothing, and even natural objects that have been given cultural meanings. Artifacts can be used to determine what people value, and how they adapt the resources they have to their needs. However, artifacts most often consist simply of souvenirs and clothing collected by researchers; they usually are under-utilized as research data themselves. Artifacts are large and lumpy and difficult to ship home. They may be immoveable, as is the case with features of the natural environment-mountains, urban environments, etc. In every case, they are difficult to analyze directly because research privileges data that can be manipulated easily- numbers and words. Nonetheless, we believe that artifacts can provide both a stimulus for collecting rich information about people and their culture, and also a window into otherwise unexamined questions in anthropological, sociological, educational, and other social science research. Visual anthropology and sociology has made use of wide photographs to supplement verbal description (Collier and Collier 1986). Anthropologists also have analyzed artifacts in the process of describing manufacturing and economies in communities they study. However, we believe that artifacts have been little used in studies of education (but see LeCompte and Preissle 1993), and especially in the study of processes of identity construction and maintenance. In an era of highly mobile populations, home culture no longer provides the sole and stable anchor for identity. Many people migrate back and forth between several countries, communities and cultures. Personal and community identity, then, must adapt to several environments at once. We believe that migrants form hybrid identities made up of components from multiple cultures and environments. Examining the artifacts that they use and surround themselves with can provide a window into dynamic processes of identity construction. In summary, as ethnographic researchers we realize the value that artifacts have had for us, as data objects and as a way to create conversations with participants about the objects, their functions, and their uses historically and currently. We believe that this issue remains insufficiently examined in the literature

Tourisme durable : les français sont-ils partants ?

International audienceIt is now well known that mass tourism can have negative impacts on the environment as well as on host populations. In response to this fact, sustainable tourism has emerged and developed. But we know very little regarding the French people attitude towards this concept. In order to improve this knowledge, the paper aims at better understanding the different degrees of agreement of French people, which types of sustainable tourism are the easiest to implement as well as who are sustainable tourists. In order to do so, a survey has been conducted on 545 respondents. It allows to identify and to characterize 5 categories of people.Des constats des méfaits du tourisme de masse sur l'environnement et les populations d'accueil est née l'idée d'un tourisme plus conforme aux principes du développement durable. Cependant, l'information manque concernant l'attitude des français face à ces pratiques. Cet article a pour objectif d'étudier les attitudes des consommateurs français vis-à-vis du tourisme durable et plus précisément, de mieux connaître leur degré d'adhésion, de savoir quelles sont les formes les plus faciles à mettre en œuvre et d'identifier les touristes enclins à pratiquer cette forme de tourisme. Une enquête sur 545 répondants permet de définir 5 classes d'individus et de les caractériser

Pour une consommation touristique plus durable : quel chemin reste-t-il à parcourir ?

Cette étude se donne pour objectif de mesurer le chemin qu'il reste à parcourir pour convertir les consommateurs à des pratiques touristiques plus durables. Pour cela, une collecte de données qualitatives a été menée auprès de 568 répondants. Chacun d'entre eux devait indiquer ce qui avait été durable versus non durable au cours de ses dernières vacances, ainsi que les freins et motivations qu'il percevait vis-à-vis du tourisme durable. Les principaux leviers qui découlent de l'étude sont l'éducation et la sensibilisation des voyageurs, le développement d'une offre durable grand public et la mise en avant de l'image d'authenticité et d'originalité de ces voyages.tourisme durable, touriste durable, perceptions du consommateur, freins, motivations

Les Français et le tourisme durable : proposition d'une typologie

Cet article présente une typologie des consommateurs français en matière de tourisme durable. Les analyses, menées sur un échantillon de 545 individus montrent l'existence de 5 profils de touristes, dont deux sont qualifiés de durables et 3 de non durables. La description des profils obtenus montre que les individus sensibles au tourisme durable sont aussi des individus qui pratiquent une consommation socialement responsable.tourisme durable, typologie, consommation socialement responsable

Tourisme durable: quelles représentations en ont les consommateurs français?

Cet article traite des perceptions et des attitudes des consommateurs Français vis-à-vis du tourisme durable. Une étude qualitative conduite sur un échantillon de 630 répondants cherche à savoir à quoi le tourisme durable est associé, quels sont les freins et les motivations vis-à-vis de cette pratique. Les résultats montrent que les répondants ont une assez bonne connaissance de ce qu'est le tourisme durable et ce malgré quelques représentations erronées. Les analyses concluent sur l'idée que le tourisme durable représente une réelle opportunité pour le tourisme de demain.tourisme durable; étude qualitative; chartes de tourisme durable; représentations du tourisme durable

Potential of Organic Rankine Cycles (ORC) for waste heat recovery on an Electric Arc Furnace (EAF)

The organic Rankine cycle (ORC) is a mature technology to convert low temperature waste heat to electricity. While several energy intensive industries could benefit from the integration of an ORC, their adoption rate is rather low. One important reason is that the prospective end-users find it difficult to recognize and realise the possible energy savings. In more recent years, the electric arc furnaces (EAF) are considered as a major candidate for waste heat recovery. Therefore, in this work, the integration of an ORC coupled to a 100 MWe EAF is investigated. The effect of working with averaged heat profiles, a steam buffer and optimized ORC architectures is investigated. The results show that it is crucial to take into account the heat profile variations for the typical batch process of an EAF. An optimized subcritical ORC (SCORC) can generate an electricity output of 752 kWe with a steam buffer working at 25 bar. However, the use of a steam buffer also impacts the heat transfer to the ORC. A reduction up to 61.5% in net power output is possible due to the additional isothermal plateau of the steam

Influence of EBR on the structural resistance of RC slabs under quasi-static and blast loading: Experimental testing and numerical analysis

Flexural strengthening of reinforced concrete (RC) structures with externally bonded reinforcement (EBR) using carbon fibre-reinforced polymers (CFRP) has in recent years received increased interest from specialists, particularly when dealing with protective structures against terrorist or accidental blast loading. Although a significant number of studies have been conducted on the failure modes of the bonded interface for quasi -static conditions, there is still limited published research on the effects of blast loading. In this paper, RC slabs externally strengthened with CFRP are tested in three-point bending as well as subjected to blast loading. The behaviour of the tested specimens under both loading regimes is evaluated with special focus on the mechanisms that lead to the disruption of the CFRP. It was found that the debonding of the CFRP was caused, in both cases, by the fracture and separation of a thin layer of concrete in the near vicinity of the bonded interface. However, the mechanisms that lead to this failure differ. A numerical model was developed and simulations performed using the finite element (FE) code LS-DYNA to investigate the validity of commonly used simplifications on the modelling of the interface in both cases. It was found that although the modelling technique used to represent the disruption of CFRP under quasi-static conditions provide accurate results, it does not return accurate predictions of the debonding of CFRP under blast loading

Ex vivo determination of bone tissue strains for an in vivo mouse tibial loading model

AbstractPrevious studies introduced the digital image correlation (DIC) as a viable technique for measuring bone strain during loading. In this study, we investigated the sensitivity of a DIC system in determining surface strains in a mouse tibia while loaded in compression through the knee joint. Specifically, we examined the effect of speckle distribution, facet size and overlap, initial vertical alignment of the bone into the loading cups, rotation with respect to cameras, and ex vivo loading configurations on the strain contour maps measured with a DIC system.We loaded tibiae of C57BL/6 mice (12 and 18 weeks old male) up to 12N at 8N/min. Images of speckles on the bone surface were recorded at 1N intervals and DIC was used to compute strains. Results showed that speckles must have the correct size and density with respect to the facet size of choice for the strain distribution to be computed and reproducible. Initial alignment of the bone within the loading cups does not influence the strain distribution measured during peak loading, but bones must be placed in front of the camera with the same orientation in order for strains to be comparable. Finally, the ex vivo loading configurations with the tibia attached to the entire mouse, or to the femur and foot, or only to the foot, showed different strain contour maps.This work provides a better understanding of parameters affecting full field strain measurements from DIC in ex vivo murine tibial loading tests

Origin and Provenance of Spherules and Magnetic Grains at the Younger Dryas Boundary

One or more bolide impacts are hypothesized to have triggered the Younger Dryas cooling at ∼12.9 ka. In support of this hypothesis, varying peak abundances of magnetic grains with iridium and magnetic microspherules have been reported at the Younger Dryas boundary (YDB). We show that bulk sediment and/or magnetic grains/microspherules collected from the YDB sites in Arizona, Michigan, New Mexico, New Jersey, and Ohio have (187)Os/(188)Os ratios ≥1.0, similar to average upper continental crust (= 1.3), indicating a terrestrial origin of osmium (Os) in these samples. In contrast, bulk sediments from YDB sites in Belgium and Pennsylvania exhibit (187)Os/(188)Os ratios \u3c\u3c1.0 and at face value suggest mixing with extraterrestrial Os with (187)Os/(188)Os of ∼0.13. However, the Os concentration in bulk sample and magnetic grains from Belgium is 2.8 pg/g and 15 pg/g, respectively, much lower than that in average upper continental crust (=31 pg/g), indicating no meteoritic contribution. The YDB site in Pennsylvania is remarkable in yielding 2- to 5-mm diameter spherules containing minerals such as suessite (Fe-Ni silicide) that form at temperatures in excess of 2000 °C. Gross texture, mineralogy, and age of the spherules appear consistent with their formation as ejecta from an impact 12.9 ka ago. The (187)Os/(188)Os ratios of the spherules and their leachates are often low, but Os in these objects is likely terrestrially derived. The rare earth element patterns and Sr and Nd isotopes of the spherules indicate that their source lies in 1.5-Ga Quebecia terrain in the Grenville Province of northeastern North America