Search results for "LAB"
showing 10 items of 7932 documents
Geometric optimal control of elliptic Keplerian orbits
2005
This article deals with the transfer of a satellite between Keplerian orbits. We study the controllability properties of the system and make a preliminary analysis of the time optimal control using the maximum principle. Second order sufficient conditions are also given. Finally, the time optimal trajectory to transfer the system from an initial low orbit with large eccentricity to a terminal geostationary orbit is obtained numerically.
Minimum Time Control of the Restricted Three-Body Problem
2012
The minimum time control of the circular restricted three-body problem is considered. Controllability is proved on an adequate submanifold. Singularities of the extremal flow are studied by means of a stratification of the switching surface. Properties of homotopy maps in optimal control are framed in a simple case. The analysis is used to perform continuations on the two parameters of the problem: The ratio of the masses, and the magnitude of the control.
Inter-laboratory evaluation of the ISO standard 11063 "Soil quality -- Method to directly extract DNA from soil samples"
2011
International audience; Extracting DNA directly from micro-organisms living in soil is a crucial step for the molecular analysis of soil microbial communities. However, the use of a plethora of different soil DNA extraction protocols, each with its own bias, makes accurate data comparison difficult. To overcome this problem, a method for soil DNA extraction was proposed to the International Organization for Standardization (ISO) in 2006. This method was evaluated by 13 independent European laboratories actively participating in national and international ring tests. The reproducibility of the standardized method for molecular analyses was evaluated by comparing the amount of DNA extracted, …
Circulating markers of retinal and optic nerve lipids
2013
Purpose Blood lipids are frequently used as a surrogate of lipid composition of peripheral tissues. Even if it is well accepted, such a relationship has never been clearly demonstrated for the eye. The aim of this study was to determine in human samples whether a lipidomic approach based on red blood cells could reveal associations between circulating and ocular lipid profiles. Methods Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on these tissues were done by both, gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS/MS). Results Gas chromatographic approach did not show…
Short term adaptive response of symbiotic N2 fixation in pea to root pruning of half the root system, linked to the availability of carbon assimilates
2014
Symbiotic N fixation of legumes is very sensitive to environmental stresses, like pea pests damaging nodulated roots. However, the impact on their N uptake capacity and plant growth has not been studied so far.We analyzed the adaptive response symbiotic N2 fixation and plant growth of pea wild type Frisson and hypernodulating mutants P64, P118 and P121 mutated respectively on genes SYM28, SYM29 and NOD3 to root pruning of half the root system at the end of the vegetative stage. The adaptive responses of pea: cv. Frisson and 3 of its hypernodulating mutants were compared under varying carbon supplies from photosynthesis.At 380 ppm, mutant P118 showed the lowest decrease of the specific activ…
Les alumnis numériques : un vecteur de transmission de valeurs communautaires
2015
Publication qui fait suite à la Journée de recherche 2013 "Transmissions : Regards transdisciplinaires" du Jeudi 12 décembre 2013 à Paris, organisée par et sous la responsabilité scientifique de : Pascal Lardellier (uB, CIMEOS/3S), Richard Delaye (groupe IGS/PROPEDIA).; National audience
La « Plateforme numérique mutualiste sur la nature et l’usage de la pierre bourguignonne » : un outil collaboratif à vocation fédératrice
2014
National audience
La CGT et la répression antisyndicale (août 1939 - décembre 1940). Entre légalisme et apprentissage de la clandestinité
2016
Starting War of France in the summer of 1939 was accompanied by a restriction of freedoms and banning the Communist Party, following the signing of the Molotov-Ribbentrop Pact on August 23, 1939. At the union level, this policy results excluding communist unionists and the dissolution of more than 600 unions. Until the fall of the Republic, the union action is divided between a legal unionism and forced into hiding unionism. The advent of the Etat Français will complete reconfiguring the social landscape. Indeed, after the dissolution of all union centers by Vichy, a final split occurs among legal union between those who agree to cooperate with the new regime and those who refuse and join a…
Evaluación de un Proyecto de Aula en Formación Profesional
2017
Our contribution is inserted into an approach of Dialogic teaching methodology and participatory understanding of evaluation practices from a perspective of inclusive culture that regards the process of teaching and learning from the reflection in action. This creates learning environments where the role of the teacher favours autonomy, creativity and confidence, adapting to the different contexts and rhythm of learning of students. The objectives of the project were achieved in designing evaluation tools and involving students in its evaluation process promoting honest, responsible and tolerant attitudes. Results/conclusions, students interpret what has been done and recognizes achievement…
Analysing the mechanisms of common ground in collaborative web-based interaction
2001
The ideas presented in this paper are challenged especially by the certain critical questions concerning web-based interaction and the qualitative analysis of such interaction and learning. The question arises whether the students from different contexts and countries are able to reach such interaction that would lead them to educationally relevant higher-level discussion and learning in web-based environments. Furthermore, as this field of study is fairly novel, there is a shortage of established methodologies for analysing computer-mediated communication and the complex phenomena it encompasses. In this presentation, we attempt to find new approaches to discover how people establish and m…