Search results for "wt"
showing 10 items of 5424 documents
Study of TiO2 nanostructures grown in a MOCVD reactor in presence of metallic catalysts. Valorization of these TiO2 nanostructures
2017
Within the Nanoform Theme, Ax Nanosciences, ICB, we realize the growth of 1D, 2D and 3D hybrid nanostructures based on TiO2 by MOCVD. Our work deals with the theoretical aspect of the formation of these nanostructures (growth and kinetic models, structure and texture) and the study of photoelectric, optical and physicochemical properties as well as the development of applications of these structures in physics (random laser), photocatalysis, energy (solar cells). Under certain perfectly controlled conditions, we obtain original TiO2 structures not yet described in the literature: membranes, rods , canals, crucibles, COHN (COaxiales Heterostructures Nanowires). Our previous work made it poss…
Lossless and nearly-lossless image compression based on combinatorial transforms
2011
Common image compression standards are usually based on frequency transform such as Discrete Cosine Transform or Wavelets. We present a different approach for loss-less image compression, it is based on combinatorial transform. The main transform is Burrows Wheeler Transform (BWT) which tends to reorder symbols according to their following context. It becomes a promising compression approach based on contextmodelling. BWT was initially applied for text compression software such as BZIP2 ; nevertheless it has been recently applied to the image compression field. Compression scheme based on Burrows Wheeler Transform is usually lossless ; therefore we imple-ment this algorithm in medical imagi…
Low-cost viscometer based on energy dissipation in viscous liquids
2001
We describe a new type of low-cost easy-to-use viscometer based on the temperature elevation in a liquid under shear flow. After calibration, this instrument can be used to measure the apparent steady state viscosity for both Newtonian and non-Newtonian liquids with no yield stress. We compute the rise in temperature due to viscous dissipation in a Couette cell and compare it to experimental results for different fluids. We show that the variation of the temperature with shear rate can be used to characterize the rheological behaviour of viscous fluids and to evaluate their viscosity in a large domain, from typically a few cP up to more than 10 P, with an accuracy of about ±5%. In contrast …
Un réexamen du modèle de gains de Mincer
1986
A re-appraisal of mincer's earnings model Starting from rough measures of formal schooling and on the job training, the earning model proposed by J. Mincer (1974) suceed to explain a substantial proportion of the variance of individual earning. The explanatory power of the model can be significantly boosted by increasing the quality of the variables. In spite of the robustness of the model, the interpretation of the results is to be taken cautiously. These results can be derived from alternative theoretical hypothesis and namely to the one known as the filter hypothesis. It is shown that a specification of the earnings function consistent with the filter hypothesis is proced to be empirical…
Measuring ‘indirect’ investments in ICT in OECD countries
2019
International audience; ICT components, such as microprocessors, may be embodied in other capital goods not recorded as ICT in National Accounts. We name ‘indirect ICT investment’ the value of embodied ICT components in non-ICT investment. The paper provides estimates of ‘indirect ICT investment’ based on detailed and unpublished Supply-Use tables (SUT) in 12 OECD countries: Australia, Belgium, Canada, Chile, Czech Republic, Denmark, France, Germany, Japan, Israel, Mexico, New Zealand, the United Kingdom, and the United States.Our main finding is that ICT investment appears significantly higher when considering its indirect component, the average increase being about 35%. The inclusion of i…
Développement postnatal et évolution du complexe craniofacial chezles rongeurs
2022
Understanding developmental mechanisms in evolution is crucial to apprehend the diversification of organismal forms. In mammals, changes occur during all development phases (prenatal and postnatal). Postnatal growth plays an essential role in the acquisition of the adult shape. During this period, the craniofacial complex undergoes many changes in functional constraint forcing the different tissue to accommodate while adjusting, along the growth and at the adult stage, to a certain level of functional performance. These different developmental interactions respond to several influencing factors such as molecular, genetic and cellular processes but also the environment. The latter will play …
A multispecies approach for modeling the ecological impact of urban development using landscape graphs
2013
International audience; Managing urban sprawl is become a major concern in the field of landscape ecology, since the land use changes involved by urban development may affect the ability of wildlife species to move across the landscape. In order to compare the ecological impact of several urban patterns, we aim at combining two complementary approaches: 1) Simulations of residential development from an initial land use map, using morphological rules of urban development (i.e. fractal vs non fractal) and accessibility constraints; 2) Models of ecological networks applied to a given natural habitat, using a landscape graphs-based approach. As landscape graphs are built according to the moving…
Comparative effect of inorganic N on plant growth and N2 fixation of ten legume crops
2018
International audience; [pas de résumé]
Détection ampérométrique d'Escherichia coli (totaux et producteurs de beta-lactamase à spectre étendu (BLSE) et d'Enterococcus spp. dans les systèmes…
2017
Treated wastewaters discharged from wastewater treatment plants (WWTP) and livestock effluents are the main sources of contamination of aquatic environments and of agricultural soils by human and animal fecal micro-organisms. Contaminated waters, especially bathing waters, may present a sanitary risk for humans if the concentrations of fecal micro-organisms are high, thus indicating the potential presence of pathogenic and/or antibiotic resistant strains. Soils and crops also can be contaminated by these micro-organisms when treated wastewaters are used to irrigate cultivated soils. Consequently, microbiological quality controls are mandatory for bathing waters and treated wastewaters to ma…
Combining ecophysiological and microbial ecological approaches to assess interaction between genotypes of Medicago truncatula and the soil bacterial …
2011
International audience; Microbial communities can play a key role in sustainable agriculture by improving crop growth. Currently, a major stake is to study the effect of the plant genotype on the shaping of the soil microbial communities in relation to the plant nutrition. Methods: The links between the plant genotype and the rhizospheric bacterial communities were assessed at both structural and functional level using a multidisciplinary approach. On the one side, the genetic structure (Automated Ribosomial Intergenic Spacer Analysis (ARISA)) and diversity (454 pyrosequencing) of bacterial communities of the rhizosphere was first analysed. On the other side, using an ecophysiological model…