Wood wasp inspired space and earth drill

In this chapter, we explain why the low gravity encountered on Mars or on the Moon and the low mass of the probes, landers and rovers that carry drilling devices limit classical drilling techniques. Novel boring solutions optimised in mass and power consumption are thus needed for space applications. Biologists have identified the wood wasp, an insect that is capable of "drilling" into wood to lay its eggs. A low mass and low power system, like an insect, capable of drilling into wood is of the highest interest for planetary drilling and terrestrial drilling alike. The general working principle of the wood wasp drill ("dual reciprocating drilling") will be exposed and the potential benefits of imitating the wood wasp for planetary drilling will be highlighted. Since the nature of wood is highly fibrous but the nature of extraterrestrial and terrestrial soils are not, it is necessary to adapt the wood wasp ovipositor to our target soils. A test bench to evaluate the influence of the different geometries and operational parameters was produced and is presented here. The dual reciprocating drilling experimental results obtained on this test bench are also highlighted. They should lead to a new and enhanced model and comprehension of dual-reciprocating-drilling

Operational modal analysis with non stationnary inputs

Operational modal analysis (OMA) techniques enable the use of in-situ and uncontrolled vibrations to be used to lead modal analysis of structures. In reality operational vibrations are a combination of numerous excitations sources that are much more complex than a random white noise or a harmonic. Numerous OMA techniques exist like SSI, NExT, FDD and BSS. All these methods are based on the fundamental hypothesis that the input or force applied to the structure to be analyzed is a stationary white noise. For some applications this hypothesis is reasonable. However in numerous situations, the analyzed structure is subject to harmonic and transient forces. Numerous methods and research has enabled to develop methods that are robust to such harmonic contributions. To enable OMA during pressure oscillations in solid rocket boosters, the authors propose to consider transient and harmonic inputs no longer as parasites but as the main force applied to the structure that must be analyzed. This is the case during pressure oscillations in rocket boosters. We propose the use of phase analysis adapted to a transient context to conduct operational modal analysis under a harmonic transient input. This time-based novel OMA method will be exposed. The theoretical developments and algorithmic implementations are exposed. First tests have been conducted on laboratory single degree of freedom setup to validate this new OMA technique and are reported here

L'uvéite récurrente équine : actualités bibliographiques

Première cause de cécité chez le cheval et modèle animal d’uvéite spontanée pour l’homme, l’uvéite récurrente équine fait l’objet de nombreuses études qui tentent d’en comprendre le déterminisme et de mettre au point de nouvelles stratégies thérapeutiques et prophylactiques. Les connaissances actuelles indiquent une prédisposition génétique de certains individus pour une réponse immunitaire lymphocytaire de type Th1 impliquant des auto-antigènes oculaires, l’infection par Leptospira, ou les deux. Alors qu’aucun vaccin préventif de l’URE n’existe, la vitrectomie par voie postérieure et l’implantation supra-choroïdienne d’un insert de cyclosporine A représentent actuellement les meilleurs moyens pour diminuer le risque de récidive

ECHAP « L’architecture des couverts végétaux : un levier pour réduire l’utilisation des fongicides ? »

L’objectif du projet ECHAP est d’identifier les possibilités de réduction de traitements fongicides via l’utilisation de l’architecture des couverts. Le projet a tout d’abord apporté des connaissances qui ont levé des verrous sur les mécanismes d’interaction. Il combine également 3 expérimentations opérationnelles au champ et un travail de modélisation du système. Les expérimentations au champ confirment l’effet de l’architecture sur le développement épidémique ainsi que l’effet marqué sur l’interception des fongicides et qui s’exprime clairement entre les variétés. Un modèle innovant et original simulant le système « architecture–épidémie-fongicide », septo3dfongi, a été développé. Il est opérationnel et permet de simuler et de raisonner des stratégies de traitements. Des critères d’évaluation multicritères des stratégies ont été également proposés

Regolith simulant preparation methods for hardware testing

International audienceTo qualify hardware for space flight, great care is taken to replicate the environment encountered in space. Emphasis is focused on presenting the hardware with the most extreme conditions it might encounter during its mission lifetime. The same care should be taken when regolith simulants are prepared to test space system performance. Indeed, the manner a granular material is prepared can have a very high influence on its mechanical properties and on the performance of the system interacting with it. Three regolith simulant preparation methods have been tested and are presented here (rain, pour, vibrate). They should enable researchers and hardware developers to test their prototypes in controlled and repeatable conditions. The pour and vibrate techniques are robust but only allow reaching a given relative density. The rain technique allows reaching a variety of relative densities but can be less robust if manually controlled

From Ideotypes to Genotypes: Approaches to Adapt Wheat Phenology to Climate Change

AbstractIntroductionSimulations using crop models can assist in designing ideotypes for current and future agricultural conditions. This approach has been often in recent years to identify avenues for adapting wheat to climate change. However, this approach has rarely been used to guide commercial breeding programs. We hypothesize that the lack of link between models and the available tools for breeding, i.e. available genetic variability and selection methods.Materials and methods- We use a modified ARCWHEAT2 phenology model and future climate data from the ARPEGE global circulation model to identify targets for future phenologies-We genotyped over 400 French cultivars for known phenology genes and confronted the genetic make-up of these varieties to their success in France over the past 25 years- We developed a methodology to link model parameters to underlying marker data. We tested the performance of the methodology against circa 60 varietiesResultsEarlier phenology may be an avenue for stress avoidance in the future.Current photoperiod sensitivity of early cultivars already poses problems in terms of adaptation, as exemplified by the interaction between Ppd-D1 and Vrn-A3We show that a gene-based model can be used to predict wheat phenology without a significant loss in predictive performance.DiscussionAnalyzing current phenology genes of existing cultivars and their adaptation allowed us to identify a limit to past breeding efforts in obtaining early cultivars. This requires that a more knowledge based approach be taken. Gene-based modelling of phenology is possible on a collection of elite, adapted varieties and provides the tools for constructing genotypes with specific allelic combinations leading to more appropriate constructions of earliness

Re-parametrisation of Adel-wheat allows reducing the experimental effort to simulate the 3D development of winter wheat

Eds. Risto Sievänen, Eero Nikinmaa, Christophe Godin, Anna Lintunen & Pekka NygrenA parameterisation of wheat architecture was developed, having high flexibility to simulate contrasted genotypes and growth conditions with a reasonably low number of parameters. Field measurements at 4-5 dates allowed to simulate crops from emergence to maturity with a good agreement between simulated and measured ground cover and GAI. Dynamics of leaf angles were shown to impact strongly ground cover

Modelling impacts of climate change on arable crop diseases: progress, challenges and applications

Combining climate change, crop growth and crop disease models to predict impacts of climate change on crop diseases can guide planning of climate change adaptation strategies to ensure future food security. This review summarises recent developments in modelling climate change impacts on crop diseases, emphasises some major challenges and highlights recent trends. The use of multi-model ensembles in climate change modelling and crop modelling is contributing towards measures of uncertainty in climate change impact projections but other aspects of uncertainty remain largely unexplored. Impact assessments are still concentrated on few crops and few diseases but are beginning to investigate arable crop disease dynamics at the landscape level