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Dr Jean Languillon (1912-2003), a major unrecognized leprologist Languillon’s contribution to the control of leprosy cannot be reduced to the manual of leprology which remains the reference for anyone working on this disease in sub-Saharan Africa. This would mean forgetting his works that established the immunological origin of leprosy and its cutaneous, adverse and neurological complications. Another major aspect, the importance of his contribution to the treatment of the disease, in particular through the development of polychimiotherapy (PCT), which has made Institut Marchoux in Bamako one of the five WHO’s collaborating centers in the field of clinical research in leprosy. Languillon was also involved in a holistic approach of the disease by creating the first leprosy surgery unit and implementing physiotherapy, orthopedic care with appropriate equipment, and social rehabilitation… without forgetting preventive aspects of complications through the necessary regular administration of treatments, and control of patients spread over wide territories, by creating a corps of leprosy nurse monitors and leprosy specialists. These will provide essential support to the doctor most often in charge of a huge sector where the need of assistance was obvious. Languillon ended his African career by creating the ILAD, Institute of Applied Leprology in Dakar, which offers the full range of care, as he always advocated. Finally, he did not resist the call of Order of Malta which offered him to share his expertise in the different countries where the Order was involved. Le Dr Jean Languillon (1912-2003), un léprologue majeur trop méconnu Disposant de documents inédits, les auteurs dressent le portrait d’un acteur essentiel dans la lutte contre la lèpre et rappellent – outre son Précis de léprologie qui reste la référence pour l’Afrique noire – ses apports majeurs, que ce soit sur l’origine immunologique de la maladie, la mise au point de schémas thérapeutiques efficaces ou la conception de stratégies pertinentes et efficaces de prise en compte du patient dans les différents aspects et complications de la maladie. L’apport du Dr Languillon dans la lutte contre la lèpre ne peut se réduire au Précis de léprologie qui reste la référence pour tout intervenant sur cette maladie en Afrique noire. Ce serait oublier ses travaux établissant l’origine immunologique de la lèpre et de ses complications cutanées, réactionnelles et neurologiques. Autre apport majeur, l’importance de sa contribution au traitement médical de la maladie, en particulier par la mise au point de la polychimiothérapie (PCT), et qui a fait de l’Institut Marchoux de Bamako l’un des 5 centres mondiaux collaborateurs de l’OMS en matière de recherches cliniques en léprologie. Jean Languillon s’est également inscrit dans une prise en charge holistique de la maladie en créant le premier service de chirurgie de la lèpre et en recourant à la physiothérapie, à la prise en charge orthopédique par un appareillage adapté, à la réhabilitation sociale… Sans oublier les aspects préventifs des complications par la nécessaire dispensation régulière des traitements et le contrôle des malades dispersés sur de vastes territoires en créant un corps d’infirmiers contrôleurs lèpre et spécialistes de la maladie qui a procuré un appui essentiel au médecin chargé le plus souvent d’un immense secteur où le besoin d’être secondé était une évidence. Il terminera sa carrière africaine en mettant en place l’ILAD, Institut de léprologie appliquée de Dakar, qui va offrir la gamme complète de prise en charge telle qu’il l’a toujours préconisée. Au terme de ce long parcours professionnel, Jean Languillon ne pourra résister à l’appel de l’Ordre de Malte qui lui proposera de faire bénéficier de son expertise les différents pays dans lesquels l’Ordre est impliqué., MTSI, Vol. 3 No 2 (2023): MTSI-Revue

The present study investigates the complex multi-scale coupled transport and electrochemical phenomena involved in charge storage in pseudocapacitors. It presents rigorously developed models for simulating pseudocapacitive electrodes in both hybrid pseudocapacitors and in three-electrode systems under cyclic voltammetry. The models account for (i) charge transport in the electrodes and electrolyte, (ii) formation and dissolution of the electric double layer (EDL) at the electrode/electrolyte interface, (iii) steric repulsions due to finite ion size, (iv) redox reactions at the pseudocapacitive electrode/electrolyte interface, and (v) insertion and deinsertion of the reaction product in the pseudocapacitive electrode. They were used to study the behavior of electrochemical pseudocapacitors and provide physical interpretation of experimentally obtained measurements.First, this study determined the respective contributions of faradaic reactions and EDL formation to charge storage in hybrid pseudocapacitors. It demonstrated the existence of two regimes for hybrid pseudocapacitors. First, a faradaic regime dominated by redox reaction and limited by the diffusion of Li in the pseudocapacitive electrode. Second, a capacitive regime dominated by the formation and dissolution of the EDL. A b-value of unity was shown to be associated with both regimes. The dip in b-value often observed experimentally was attributed to the transition between the two regimes.Second, this study presented an extensive parametric study for the design of the pseudocapacitive electrode in a hybrid pseudocapacitor. Increasing the fraction of the potential window dominated by faradaic current was found to increase the performance of the device. Indeed, the faradaic reactions resulted in a significantly larger current magnitude than the EDL charge storage. The effect of the electrode thickness and Li diffusion coefficient on this fraction were investigated for different scan rates. To study the interplay between these parameters, a scaling analysis was performed to identify the relevant dimensionless similarity parameters governing Li transport and intercalation in the pseudocapacitive electrode. A dimensionless parameters was derived accounting for the respective contributions of the thickness, diffusion coefficient and scan rate. Furthermore, above a critical value, the device was found to operate under a diffusion-independent regime.Finally, this study presented a model for simulating individual pseudocapacitive electrodes in three-electrode experiments. Notably, this model accounted for the variation of the redox reaction equilibrium potential with the oxidation state of the electrode. It was found to agree qualitatively with experimental measurements well and was used to provide physical interpretation to experimental measurements for Nb2O5 electrodes.These models and results could help in the design of pseudocapacitive electrodes to achieve maximum energy and power density.