A classical explanation of quantization

In the context of our recently developed emergent quantum mechanics, and, in particular, based on an assumed sub-quantum thermodynamics, the necessity of energy quantization as originally postulated by Max Planck is explained by means of purely classical physics. Moreover, under the same premises, also the energy spectrum of the quantum mechanical harmonic oscillator is derived. Essentially, Planck's constant h is shown to be indicative of a particle's "zitterbewegung" and thus of a fundamental angular momentum. The latter is identified with quantum mechanical spin, a residue of which is thus present even in the non-relativistic Schroedinger theory.Comment: 20 pages; version accepted for publication in Foundations of Physic

Enhanced Microwave Absorption Properties of Intrinsically Core/shell Structured La0.6Sr0.4MnO3Nanoparticles

The intrinsically core/shell structured La0.6Sr0.4MnO3nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of −41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than −10 dB is obtained in the 5.5–11.3 GHz range for absorber thicknesses of 1.5–2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La0.6Sr0.4MnO3nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials

Modeling the long-term durability of concrete barriers in the context of low-activity waste storage

The paper investigates the long-term durability of concrete barriers in contact with a cementitious wasteform designed to immobilize low-activity nuclear waste. The high-pH pore solution of the wasteform contains high concentration level of sulfate, nitrate, nitrite and alkalis. The multilayer concrete/wasteform system was modeled using a multiionic reactive transport model accounting for coupling between species, dissolution/ precipitation reactions, and feedback effect. One of the primary objectives was to investigate the risk associated with the presence of sulfate in the wasteform on the durability of concrete. Simulation results showed that formation of expansive phases, such as gypsum and ettringite, into the concrete barrier was not extensive. Based on those results, it was not possible to conclude that concrete would be severely damaged, even after 5,000 years. Lab work was performed to provide data to validate the modeling results. Paste samples were immersed in sulfate contact solutions and analyzed to measure the impact of the aggressive environment on the material. The results obtained so far tend to confirm the numerical simulations

Les gouttes marcheuses - Une forme de dualité onde-particule à échelle macroscopique ?

Une goutte rebondissant sur la surface d’un liquide oscillant peut se coupler à l’onde de surface qu’elle émet et devenir propagative. Le «marcheur» résultant est un objet macroscopique cohérent associant la particule et l’onde. Les interactions de ces marcheurs entre eux et celles qu’ils ont avec leur environnement sont surprenantes, car médiées par leurs ondes

Détermination des sources de sols par les empreintes EPR de la matière organique dans deux spéléothèmes

International audienceOrganic matter (OM) sources and transfers are critical questions at the crossroad of ecology, hydrology and paleoenvironmental studies in karst environments. Recently chemical or isotopic characterisations of these organic matters have demonstrated their diversity in karst water and speleothems. However, knowledge of their origin and transfer from soil needs to be improved especially in karst environments where a mosaic of soils occurs. Here we investigate the applicability of the Electron Paramagnetic Resonance (EPR) signature of OM to seek different soil fingerprints in speleothems. The positions and the shapes of semiquinone-type radical’s EPR lines are considered as a robust signature of the organic matter through the different compartment of karst ecosystems. We demonstrate that the combination of EPR lines simulation constitutes a fingerprint that discriminates folic Leptosol developed on limestone outcrops from eutric Cambisols located in the dolines and topographical depressions. We also report the conservation of the thinner OM EPR lines after a water extraction of the organic matter from soils. Finally, OM EPR signatures were detected in two different speleothems sampled near each other: a stalagmite and a subaqueous flowstone. An unexpected two-orders-of-magnitude discrepancy between the free radical concentrations of the subaqueous flowstone and the soils on one hand, and the low free radical concentration of the stalagmite samples on the other, was ascribed to the kinetics of conformational changes in OM occurring during their transfer through karst either in fast or in slow water pathways. A folic Leptosol fingerprint was found in stalagmite and conversely, an eutric Cambisol fingerprint was found in the flowstone sample. This unexpected difference between the EPR signatures of the flowstone sample and stalagmite sample was ascribed to the masking of the Leptosol EPR signature (due to the low concentrations of free radicals) in the case of the flowstone sample and to the fact that the EPR signature of the stalagmite sample clearly shows the Leptosol is the sole source of the OM. Finally, the folic Leptosol fingerprint remains steady over the last four centuries covered by the stalagmite demonstrating that the source of the OM is stable over the growth period strengthening the interest of OM entrapped in speleothem for paleoenvironment studies

Tracing Natural Organic Matter at the Scale of Drainage Basins

International audienc