Enhancing heat transfer at low temperatures by laser functionalization of the inner surface of metal pipes.

The latent heat transfer during vapour condensation in the condenser section of passive heat transport devices such as the two-phase closed thermosiphon is limited by film condensation. Dropwise condensation provides an increase of the heat transfer coefficient by up to one order of magnitude and can be achieved with a water-repellant surface. The inner surface of pipes made from stainless steel was functionalized by laser surface texturing with ultrashort laser pulses and subsequent storage in a liquid containing long-chained hydrocarbons. The pipes were separated into half-pipes by wire eroding to enable laser texturing of the inner surface, and were then joined by electron beam welding after laser texturing. As a result, superhydrophobic and water-repellent surfaces with a contact angle of 153° were obtained on the inner surface of the pipes with a length of up to 1 m. The functionalized pipes were used in the condenser section of a two-phase closed thermosiphon to demonstrate a heat transfer rate of 0.92 kW at 45 °C, which is approximately three times the heat transfer rate of 0.31 kW of a smooth reference pipe.

[Natural or interactive kinds? The transient mental disorders in Ian Hacking's lectures at the Collège de France (2000-2006)]. / Natural or interactive kinds ? Les maladies mentales transitoires dans les cours de Ian Hacking au Collège de France (2000-2006) Natural or Interactive Kinds? Die Trensienten Geistesstörungen in Ian Hackings Vorlesungen Am Collège de France (2000-2006).

The concepts developed by Ian Hacking during his lectures at the Collège de France (2000-2006) have provided an important contribution to the debates within the field of philosophy of psychiatry. Professor at the Chair of Philosophy and History of Scientific Concepts after Michel Foucault, Hacking is the author of a reflection on the classification of mental disorders, which arises from the problem of the natural kinds. In order to explain the case studies developed in Hacking's Paris lectures, we first go back to the definition of a series of concepts, then we discuss the status of his scientific metaphors. Finally we analyze the relationship between the notions, respectively, of "transient mental illness" and "culture-bound syndrome". We emphasize that the latter derives from the Canadian transcultural psychiatry.

[Elderly and disease: a philosophic glance]. / Vieillesse et maladie: un regard philosophique.

Cancer in elderly patients is the sign of a biosocial mutation of the human societies. It is a complex problem with multiple aspects--namely health care, economic, environmental considerations. This objective description is not sufficient: the psychological and emotional aspects of the life of elderly patients must also be evoked. To respect the autonomy and freedom of the patient, personalized healthcare are requested, and the conception of ageing must change. double dagger.