4,316 research outputs found
Effects of pregrowth and freezing conditions on the resistance of meristems of date palm (Phoenix dactylifera L. var. Bou Sthammi Noir) to freezing in liquid nitrogen
Effect of thawing and recovery conditions on the regrowth of meristems of date palm (Phoenix dactylifera L.) after cryopreservation in liquid nitrogen
Quantitative assessment of pinning forces and the superconducting gap in NbN thin films from complementary magnetic force microscopy and transport measurements
Epitaxial niobium-nitride thin films with a critical temperature of Tc=16K
and a thickness of 100nm were fabricated on MgO(100) substrates by pulsed laser
deposition. Low-temperature magnetic force microscopy (MFM) images of the
supercurrent vortices were measured after field cooling in a magnetic field of
3mT at various temperatures. Temperature dependence of the penetration depth
has been evaluated by a two-dimensional fitting of the vortex profiles in the
monopole-monopole model. Its subsequent fit to a single s-wave gap function
results in the superconducting gap amplitude Delta(0) = 2.9 meV = 2.1*kB*Tc, in
perfect agreement with previous reports. The pinning force has been
independently estimated from local depinning of individual vortices by lateral
forces exerted by the MFM tip and from transport measurements. A good
quantitative agreement between the two techniques shows that for low fields, B
<< Hc2, MFM is a powerful and reliable technique to probe the local variations
of the pinning landscape. We also demonstrate that the monopole model can be
successfully applied even for thin films with a thickness comparable to the
penetration depth.Comment: 6 pages, 6 figures, 2 table
Cryopreservation of grape embryogenic cell suspensions : 2. Influence of post-thaw culture conditions and application to different strains
Choice of studies at university, personality and socio-economic status. Comparison between French students in a public social sciences and humanities faculty and Brazilian law students in a private faculty
Several studies have examined the links between personality and choice of studies, particularly from a longitudinal point of view. This original research proposes to study these aspects a posteriori. The Rotter questionnaire (1966) was completed by two groups of students in psychology (N=65) and law (N= 91). The other particularity of the samples concerns the location and the differences in socio-economic backgrounds: privileged for law students in Brazil, modest for students in psychology in France. Most of the hypotheses put forward, particularly those related to the citizenship and political aspects, are verified on the basis of the binomial test
Histo-cytological study of apices from in vitro plantlets of date palm (Phoenix dactylifera L.) during a cryopreservation process
Robust valence-induced biases on motor response and confidence in human reinforcement learning
Robust valence-induced biases on motor response and confidence in human reinforcement learning
- …