Typical disturbances in temperature-time curves and loops in heating cooling cycles suggest large convection effects generated by small changes in spacetime density profiles. These observations are fully explained by a broad theoretical approach that takes into account the complex phenomena that occur in the border layer domain. The comparison between theory and experiment shows how convective motion propagates from the boundary layer to the inner zone of the liquid (central core). Thanks to the extreme sensitivity of the temperature behaviour to relatively small density variations, a fairly simple test apparatus makes it possible to obtain complete information on the density profile of 4°C. Experimental data in temperature ranges between 0°C and 8°C can “feel” the asymmetry in the density curve around 4°C, which is about 8 parts per million. Our results may shed some light on the experiments conducted by Azouni on the 4°C hystrenetic loop. Experimental data on the free convection of water in the field of maximum density are interpreted by a theoretical model. The concordance between our theory and the experimental data is excellent. Although the study of ion-atomic collisions is a mature field of nuclear physics, the large differences between experiment and theoretical calculations are still common. Here we present experimental results at high pulse resolution for helium ionization, induced by 1-MeV protons, and compare them with theoretical calculations. The overall harmony is remarkably good, and even the first approximation of the Born gives a good concordance between theory and experience. This has been expected for several decades, but it has not yet been done.

The influence of projectile co-ence effects on measurement data is the subject of a brief debate in the perspective of a persistent dispute over the existence of node structures in electron emission distributions. (a) projectile moments at the laboratory level xy, gated on 0±30° and φplab=180±30° (Gate px) or φplab=90±30° and φplab=− 90±30° (Gate py). (b) Experimental distributions of electron angles in the C plane, fermented and ungated. Electron angle distributions for solid energy Ee=6.5±3.5 eV and pulse transmission of q=0.75±0.25 a.u. (a) Experimental result and (b) theoretical distribution based on FBA calculations. The surfaces marked as A and C correspond to what is called the azimuthal plane and coplanar geometry. (c) and (d) represent 3D representations of contour diagrams (a) and (b). The blue arrow indicates the direction of q and the green arrow indicates the initial beam axis (z). .

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