Search results for "efficiency."
showing 10 items of 1362 documents
Identification of the contaminants present on the surface of lactose for pharmaceutical use and analysis of the impact of their presence on the inter…
2018
The discovery of the problem will go through training techniques at the nanoscale characterization and chemical analysis, the discovery of the industrial problem in society Armor Proteins, the validation of a pharmaceutical lactose. With the aim to increase our knowledge on powders for food or pharmaceutical use, we propose to study the effect of manufacturing processes, shaping, granulation on the reactivity of powders. The first part is devoted to the effect of purity on interactions-Lactose Lactose and Lactose-API measured / quantified by near-field techniques (AFM, SMM, MSAFM) under ambient atmosphere and under stressful conditions storage. Deriving a second portion of the preceding par…
Quasi-phase-matched third harmonic generation in optical fibers using refractive-index gratings
2011
International audience; The purpose of this work is to demonstrate the quasi-phase-matching of third harmonic generation process in optical fibers using refractive-index gratings. We compare conversion efficiency calculated with analytical coupled modes theory and numerical approach employing system of coupled generalized nonlinear Schrödinger equation. Moreover, we show that introducing the phase matching condition that takes into account the nonlinear contribution to propagation constants significantly increases the conversion efficiency by several orders of magnitude. Finally we optimize the grating constant to maximize conversion efficiency.
Integrated low drive voltage electro-optic Bragg modulator using a, periodically poled lithium niobate
2017
Periodically poled lithium niobate (PPLN) is currently used for frequency conversions using quasi-phase-matching, thanks to its high nonlinear coefficients and mature poling process. PPLN can also be attractive for electro-optic (EO) applications. Several studies have been conducted on PPLN-based EO deflectors, and recent realizations have lower the required applied voltage under hundred volts [1]. Indeed, for practical EO applications drive voltages as low as 5 V are usually required. For this purpose, we use a recent technique to realize high-quality isolated crystalline film out of LN [2] to implement an EO Bragg deflector with a drive voltage below 10 V. In this work we present an effic…
Low drive voltage electro-optic Bragg deflector using a periodically poled lithium niobate planar waveguide
2016
International audience; An electro-optic Bragg light deflector is demonstrated in a thinned, periodically poled lithium niobate planar waveguide confined between two silica layers on a silicon substrate. More than 97% of diffraction efficiency is obtained with an operating wavelength of 633 nm for the two orthogonal light polarizations with a drive voltage of about 5 V. The temporal electric drift and the response time of the component are also studied.
Comparative effect of inorganic N on plant growth and N2 fixation of ten legume crops
2018
International audience; [pas de résumé]
Quantification of nitrogen fluxes and explanatory plant traits during a two year legume-cereal rotation
2018
National audience; A better understanding of how plant growth, N nutrition and symbiotic nitrogen fixation (SNF) are influenced by soil inorganic N availability, for a wide range of legume species, is crucial to optimise legume productivity, N2 fixation, while limiting environmental risks such as N leaching. A comparative analysis was performed for ten legume crops, grown in a field experiment and supplied with four levels of N fertiliser. Dry matter, N concentration and SNF were measured. Parallely, root traits were studied in a greenhouse experiment. For most species, inorganic N inputs had little effect on plant growth and N nutrition. SNF was negatively affected by soil inorganic N avai…
New perspectives and approaches in plant growth-promoting rhizobacteria research
2007
International audience; In the context of increasing international concern for food and environmental quality, use of Plant Growth-Promoting Rhizobacteria (PGPR) for reducing chemical inputs in agriculture is a potentially important issue. PGPR are root-colonizing bacteria that exert beneficial effects on plant growth and development, but they can be also employed in the control of plant pathogens, for enhancing the efficiency of fertilizers, and for degrading xenobiotic compounds. This book provides an update by renowned international experts on the most recent advances in the ecology of these important bacteria, the application of innovative methodologies for their study, their interactio…
Comparaison de l’efficience de cinq souches de Rhizobium sur 18 génotypes de pois
2014
Legume-rhizobium association leads to the production of nodules on plant roots, in which atmospheric nitrogen is caught by the bacteria and exchanged for plant carbohydrates. This symbiotic association is probably the best way to increase nitrogen fertilization without using biological or chemical input. Symbiosis mechanisms between both species are thus a challenge for the current research. Previous studies have shown that rhizobia are not equally selected by the different pea genotypes. The objective of this study was to assess if peas select the most efficient bacterial strain. In order to answer this question, we sowed 18 pea genotypes and inoculated each of them with five different rhi…
Légumineuses et prairies temporaires : des fournitures d'azote pour les rotations
2015
Intervention présentée aux Journées de l'AFPF, "La fertilité des sols dans les systèmes fourragers", les 8 et 9 avril 2015; Les atouts des légumineuses (fixation symbiotique, diversité fonctionnelle...) leur permettent de contribuer à la fertilité des sols, à l'amélioration de la durabilité de l'agriculture et de l'autonomie protéique des systèmes alimentaires. Il convient donc de mieux connaître leurs rôles, directs et indirects, dans les flux d'azote des rotations.Les légumineuses fourragères (en culture pure ou dans des couverts multispécifiques) représentent une grande part des apports azotés symbiotiques. Il existe une grande diversité d'implication des légumineuses dans les rotations.…
Observateur et contrôle optimal : améliorer l'efficacité de la conduite automobile avec Kalman et Pontryagin
2010
The PhD presents a combined approach to improving individual car efficiency. An optimal observer, the Extended Kalman Filter, is used to create an efficiency model for the car. Particular attention was paid to handling the asynchronous and redundant nature of the measurement data. A low-cost sensor suite developed to measure data is described. This sensor suite was installed on multiple vehicles to good success. It employsan accelerometer, gps, fuel injector timer, and Vss input to measure all the data necessary to reconstruct the car's state. This observer and sensor suite can be used as the base for any study which requires car efficiency maps, allowing research to proceed without manufac…