University of Le Havre

Multi-source systems are gaining attention as an effective approach to seamlessly incorporate renewable energies within electrical networks. These systems offer greater flexibility and better energy management possibilities. The considered multi-source system is based on a 50 MW wind farm connected to battery energy storage and electrolyzers through modular multi-level DC/DC converters. Wind energy systems interface with the DC-bus via rectifier power electronics that regulate the DC-bus voltage and implement optimal power extraction algorithms for efficient wind turbine operation. However, integrating intermittent renewable energy sources with optimal microgrid management poses significant challenges. It is essential to mention that the studied multi-source system is connected to the DC loads (modular electrolyzers and local load). This work proposes a new regulation method designed specifically to improve the performance of the system. In this strategy, the excess wind farm energy is converted into hydrogen gas and may be stored in the batteries. On the other hand, when the wind speed is low or there is no excess of energy, electrolyzer operations are stopped. The battery energy management depends on the power balance between the DC load (modular electrolyzers and local load) requirements and the energy produced from the wind farm. This control should lead to eliminating the fluctuations in energy production and should have a high dynamic performance. This work presents a nonlinear control method using a backstepping concept to improve the performances of the system operations and to achieve the mentioned goals. To evaluate the developed control strategy, some simulations based on real meteorological wind speed data using Matlab are conducted. The simulation results show that the proposed backstepping control strategy is satisfactory. Indeed, by integrating this control strategy into the multi-source system, we offer a flexible solution for battery and electrolyzer applications, contributing to the transition to a cleaner, more resilient energy system. This methodology offers intelligent and efficient energy management.

RÉSUMÉLes ouvrages portuaires constituent des projets particuliers pour l’ingénierie, du fait qu’ils agrègent plusieurs spécificités en interaction. Les modifications d’exploitation des quais et des terre-pleins conduisent parfois à devoir réutiliser des ouvrages existants d’âges variables. Dans ces situations, la maîtrise des déplacements des différents ouvrages est fondamentale et nécessite la prise en compte de l’interaction sol-structures. #À partir de l’exemple des renforcements du quai Joannès-Couvert au Havre pour la construction d’un quai de 200 mètres dit « Jack-up », dédié à l’accueil de navires auto-élévateurs permettant le chargement de composants lourds stockés en bord à quai, et d’un quai de 200 mètres dit « Lo-Lo », dédié à l’import et à l’export de différents composants éoliens, cet article vise à illustrer par des cas concrets la nécessité de prendre en considération l’interaction sol-structures.

Epoxy resins are complex chemical molecules belonging to the group of thermosetting plastic materials.1 They are used in many professional fields, particularly in the construction industry. They are strong sensitizers and are one of the most frequent causes of occupational allergic contact dermatitis (ACD).2 They are also increasingly used for creative leisure activities, with a risk of sensitization, as highlighted by the three following cases. A 60-year-old woman developed bilateral eyelid and facial oedema, progressively worsening for over 10 days, initially mistaken for ACE inhibitors induced angioedema. On Day 10, she presented a severe desquamative eczema of the eyelids, pulp of the thumbs/indexes and earlobes (Figure 1). The investigation revealed the making and wearing of earrings made with a new epoxy resin ordered on the Internet. A 64-year-old woman consulted for itching eruption of the face, with involvement of the lips, chin and eyelid oedema for 8 days (Figure 2). On questioning, the patient indicated that she had used epoxy resin for decorative purposes for several days. A 41-year-old woman was consulted for severe eczema involving forearms, eyelids and both ears. Her hobby was plastic art, with regular handling of paint cans and epoxy resin. After each manipulation of these resins, she felt pruritus. Patch tests for the three patients were carried out with the European baseline series and epoxy series (Chemotechnique Diagnostics, Vellinge, Sweden) using IQ Ultra chambers. Perfumes and plastics and glues series were added for Patient 2. Patch tests were occluded for 48 h and readings were performed on Days (D)2 and D3. Positive reactions were noted to epoxy patch (++), bisphenol F (++) but also to fragrance mix I (++) and textile dye (++) for Patient 1. Patch tests were positive to bisphenol A and bisphenol F for Patient 2 (both ++) and Patient 3 (both +++). The three patients became symptom-free after allergens' avoidance and treatment with topical corticosteroids. We present in this article three new cases of ACD to resin epoxy, used by women for creative leisure. ACD to epoxy resin is more frequently described in occupational exposure, with a prevalence from 0.9% to 12.5%,1, 2 with a higher proportion of men.3 However, in a study conducted in Finland, non-occupational sensitization sources account for approximately one-third of epoxy resin sensitization cases. The most common sources were materials used in domestic renovation, construction projects and in boat repair.3 Four cases of direct and airborne ACD to epoxy resin in women, involving hands, forearms, but also eyelids and neck, as in our cases, have been recently reported. They were due to epoxy resin exposure in the context of creative hobbies, such as the making of dried flowers,4 craft modelling5 or small objects with Tik Tok tutorial.6 These recreational hobbies are increasing, promoted by social networks. However, specific safety measures during handling are often inadequate because hobbyists are not enough informed on how to adequately protect themselves when using epoxy resins. The epoxy resin-containing products are easily available on the Internet, without warning regarding potential skin sensitization risks. Consequently, we should be aware of the potential risk of the emergence of a new ‘epidemic’ ACD caused by epoxy resin, especially in women and minors. It is to note that the association between positive reactions to epoxy resin and fragrance mix I, found in Patient 1, has already been described in previous studies: further studies are necessary to determine if it is coincidental or related to similar chemical structures.7, 8 In conclusion, our three cases highlighted the importance of performing a detailed medical history, also asking about hobbies. Moreover, it is necessary to better regulate the sale and use of epoxy resin for recreational hobbies. Stricter legal measures should be taken, warning about the risk of allergic reactions and implementing prevention measures. I. Temam: Conceptualization; methodology; writing – original draft; writing – review and editing. O. Bauvin: Conceptualization; methodology. C. Boulard: Conceptualization; methodology. The authors declare no conflicts of interest. Patients' consents were obtained.

analysis and policy advice with the aim of promoting sustainable and equitable development. The Institute began operations in 1985 in Helsinki, Finland, as the first research and training centre of the United Nations University. Today it is a unique blend of think tank, research institute, and UN agency-providing a range of services from policy advice to governments as well as freely available original research. The Institute is funded through income from an endowment fund with additional contributions to its work programme from Finland and Sweden, as well as earmarked contributions for specific projects from a variety of donors.

En la búsqueda de sociedades sanas y vigorosas que garantizaran el futuro de la nación, el inmigrante se convirtió en un sujeto social y político a través del cual se construirían Estados-nación «civilizados». Se seleccionaría a los más «aptos», a aquellos que traerían no solo los rasgos biológicos necesarios para mejorar la «raza» latinoamericana, sino también comportamientos sociológicos propios de sociedades «civilizadas». Se pretendía estimular una inmigración «deseable» y prohibir la entrada de aquella que supusiera una amenaza para el componente biológico de la nación. En este contexto sociopolítico y científico, la eugenesia se convirtió en la ciencia que se encargaría de seleccionar, desde la perspectiva sociobiológica, al «buen» inmigrante y desechar al «malo». Colombia, país que no fue ajeno a este fenómeno transnacional, es el punto de partida de este artículo.

In this contribution the efficiency maps of synchronous machines are analyzed. The tool developed to draw these efficiency maps allows considering the synchronous machines electromagnetic parameters and related losses. It will be exploited to analyze the effects of the different parameters on the efficiency maps. The developed tool is based on the synchronous machines electrical circuits models in the Park's referential frame. The adopted modeling approach allows considering all types of classical synchronous machines: wound field synchronous machines, permanent magnet synchronous machines, hybrid excited synchronous machines and synchronous reluctance machines. It can even indirectly consider the effect of magnetic saturation. These analyses will help identify parameters sets allowing optimizing the energy efficiency of synchronous machines for a given application, as electrical traction.