Le personnel de l’aérostation maritime française (1917-1919)

La marine a mené des expériences d’aérostation à la fin du XIXe siècle mais c’est du 1er mai 1916, pour faire face au nouveau péril sous-marin, que date son organisation véritable. Il n’y avait pas d’équipage type. L’équipage était fonction du volume du ballon, même si certaines spécialités étaient obligatoires. Le pilote d’altitude était un officier. Il pouvait cumuler cette fonction avec celle de commandant de bord. Les autres personnels étaient marins ou officiers-mariniers (pilote de direction, mécanicien, radio-TSF, canonnier, etc.). Cette étude, menée à partir des rôles d’équipages, a permis de dégager trois groupes : les techniciens, la manœuvre au sol, les autres marins du CAM. Les spécialistes (brevetés d’ateliers d’aéronautique) étaient peu nombreux. Les matelots sans-spécialité constituaient même la moitié des personnels de l’aérostation, ce qui n’était pas le cas dans l’aviation. Le fonctionnement d’un Centre d’aérostation était différent de celui d’un Centre d’aviation. L’origine des cadres, le nombre important de non-spécialistes rapprochait davantage ces CAM des ports de patrouilleurs, que des unités d’aviation au personnel composé de spécialistes.The personnel of French maritime aerostation (1917-1919): The example of Brittany and Loire patrols.The Navy conducted aerostation [balloon and dirigible] experiments in the late nineteenth century but facing the new submarine threat, it began a special study on 1 May 1916. There was not one type of crew. Although some specialties were required, the crew was based on the volume of the balloon. The flight pilot was an officer. He could combine this function with that of the captain. The other personnel were sailors or petty officers (navigator, mechanic, radio operator, gunner, etc.). The study focused on the duties of crew members and identified three groups: technicians, ground control, and other sailors.  Specialists (with certified aeronautical skills) were few. Crew members without a specialty constituted about half the aerostation personnel, which was not the case in aviation. The operation of an aerostation center was different from that of an aviation center. The origin of the cadres, the large number of non-specialists made the aerostation centers resemble patrols in ports more than aviation units composed of specialists

The adiabatic invariant of any harmonic oscillator : an unexpected application of Glauber's formalism

In this theoretical paper, we propose a general derivation of the adiabatic invariant of the n-degree-of-freedom harmonic oscillator, available whichever the physical nature of the oscillator and of the parametrical excitation it undergoes. This derivation is founded on the use of the classical Glauber variables and ends up with this simplest result: the oscillator's adiabatic invariant is just the sum of all the semiclassical quanta numbers associated with its different eigenmodes

Using infrared and raman microspectroscopies to compare ex vivo involved psoriatic skin with normal human skin

Psoriasis is a chronic dermatosis that affects around 3% of the world’s population. The etiology of this autoimmune pathology is not completely understood. The barrier function of psoriatic skin is known to be strongly altered, but the structural modifications at the origin of this dysfunction are not clear. To develop strategies to reduce symptoms of psoriasis or adequate substitutes for modeling, a deep understanding of the organization of psoriatic skin at a molecular level is required. Infrared and Raman microspectroscopies have been used to obtain direct molecular-level information on psoriatic and healthy human skin biopsies. From the intensities and positions of specific vibrational bands, the lipid and protein distribution and the lipid order have been mapped in the different layers of the skin. Results showed a similar distribution of lipids and collagen for normal and psoriatic human skin. However, psoriatic skin is characterized by heterogeneity in lipid/protein composition at the micrometer scale, a reduction in the definition of skin layer boundaries and a decrease in lipid chain order in the stratum corneum as compared to normal skin. A global decrease of the structural organization is exhibited in psoriatic skin that is compatible with an alteration of its barrier properties