29/06/2011

The art of structures

chernetskiy090700066.jpgThe concept of structure has always been a fundamental aspect of building. Until the Renaissance the statics of constructions was based solely on experience, intuition, experimentation with models and empirical rules, but the scientific revolution transformed this discipline into a true science. Since the mid-1700s it has been possible to calculate structures, analyzing their mechanical behavior. Their most efficient form can be determined by mathematical means, and the measures required to ensure their strength and stability can be set by comparing the internal forces with the strength of the materials. Through the technological developments and new materials that have emerged during the industrial revolution, the science of construction has made a range of new structural solutions possible. This phase required greater specialization, and the builder was replaced by two professional roles: the architect and the engineer.

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15:53 Publié dans Science | Lien permanent | Commentaires (1)

27/06/2011

De Rousseau à Starobinski

2819047-style-art-background-vintage-books-and-candles.jpgLa question d’identité nationale se pose de manière particulièrement complexe dans le cas de la suisse dont l’unité est problématique avec ses vingt-six cantons et demi-cantons, ses quatre langues nationales, ses divergences confessionnelles, sa géographie tourmentée impliquant une vie économique très différente d’une région à l’autre. Y a-t-il une identité helvétique ? Ou en d’autres termes, pour reprendre une expression utilisée par Gonzague de Reynold, existe-t-il un «esprit national» suisse? Cette question identitaire peut paraître obsolète à une époque où la planète n’est plus qu’un grand village; elle refait cependant surface, comme si le retour aux racines était un antidote à cette uniformisation effrayante. Cette quête identitaire n’est du reste pas propre à la suisse; en France, elle renaît immanquablement lors des élections présidentielles.

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De mil, d’or et d’esclaves

7467638-photographing-the-desert-of-southern-morocco-on-a-day-of-dune.jpgDepuis la plus haute Antiquité des sociétés originales se sont développées au sud du Sahara, cultivant, dans des conditions écologiques et climatiques souvent difficiles, le mil en zone sahélienne et des tubercules comme le manioc ou la patate douce en zone forestière. Leur richesse était avant tout fondée sur le commerce international de l’or et des esclaves.

Pendant l’époque romaine et une grande partie du Moyen Age jusqu’à la découverte des Amériques, l’or utilisé pour les monnayages européens provenait d’Afrique de l’Ouest, au-delà du Sahara. Giovannini, de l’Université de Genève (2000), montre que les Romains avaient des problèmes d’approvisionnement en or et qu’ils devaient avoir recours aux ressources africaines.

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15:34 Publié dans Histoire | Lien permanent | Commentaires (0)

24/06/2011

The social fabric of the networked city

6716600-the-center-of-europe-on-map.jpgThe Social Fabric of the Networked City aims to reconsider sociological perspectives on urban phenomena by proposing a dynamic exploration of the links between infrastructural and technological aspects of the urban order, power relations and everyday life experiences. This perspective circumvents the immaterial aura of post-modern urban analysis and the material determinism that characterizes the structural approach to the city.

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15:52 Publié dans Urbanisme | Lien permanent | Commentaires (1)

22/06/2011

Microfabricated cortical neuroprostheses

images?q=tbn:ANd9GcS2L1rzZagSnEst4VE6EX1KD-uyg3G-n7ezwYNZk82lzy3KxnOf9QThe field of neuroprosthetics has important applications in medicine and science. In clinical settings, neural stimulation and recording implants promise to introduce new capabilities in restoring functions of the central nervous system (CNS) lost to trauma or disease. In basic research settings, neuroprosthetic devices remain one of the most important tools for those neuroscientists who work to elucidate the brain’s functions. Clinical therapies using neural stimulation include cochlear stimulation for the deaf; epidural spinal stimulation for the treatment of pain [3]; cortical or vagus nerve stimulation for epilepsy; and several other emerging indications including retinal stimulation for the blind.

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20/06/2011

Monte Verità

27HaeuserimBau.jpgChacun peut aujourd’hui gravir à pied les quelques centaines de mètres qui, aux abords d’Ascona, au Tessin, mènent de la rive du lac Majeur au faîte d’une colline nommée depuis 1900 Monte Verità, montagne de la vérité. Des chemins et des escaliers bordent une congestion de villas, d’immeubles cossus et d’hôtels, mais parvenu au sommet et se tournant vers le lac, le promeneur est encore violemment saisi. Il se croit précipité dans un paysage d’eau scintillante d’un bleu intense, calme miroir sous des versants abrupts. Il éprouve la sensation de se trouver sur un axe vertical qui perce le monde.

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17/06/2011

Rem Koolhaas

xinsrc_dad2247a3296422d904474c1ae925d37_1.jpgRemmert Koolhaas was born in 1944 in Rotterdam, where bombing in World War II had erased, as in Berlin, the image of the historical city. With his family he moved to Jakarta, Indonesia, in 1952 and staying until 1956, and then to Brazil, where he admired the works of Oscar Niemeyer. Back in Holland he would often spend time drawing in the architecture studio of his grandfather, Dirk Roosenburg. In 1963 he began to work for the weekly of the Dutch liberal right, “De Haagse Post”, doing layout and writing on cinema, literature, music, politics, sports, sexuality, art and architecture (including articles on Hendricus Theodorus Wijdeveld and Le Corbusier, as well as interviews with Constant Nieuwenhuys and Federico Fellini).

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15/06/2011

Analytical and physical electrochemistry

diego_cervo090400018.jpgFor historical reasons, physical electrochemistry and analytical electrochemistry are often taught separately. The purpose of this course book is to bring these two subjects together in a single volume, so as to bridge the fundamental physical aspects to the analytical applications of electrochemistry. The philosophy of this book has been to publish in extenso all the mathematical derivations in a rigorous and detailed manner, in such a way that the readers can understand rather then accept the physical origins of the main electroanalytical principles.

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15:23 Publié dans Science | Lien permanent | Commentaires (2)

13/06/2011

Advanced fiber optics

gunnar3000100600580.jpgFew techniques have had an impact on society that can compare to that of fiber optics. These tiny hair-sized glass wires have deeply transformed, at the dawn of this third millennium, access to information, modes of communicate, and even the behavior of consumers. This tremendous impact was rightfully honored by the presentation of the 2009 Nobel Prize in Physics to charles K. Kao, who predicted in 1966, by careful calculations, that optical fibers could transmit a broadband signal over distances outperforming any existing transmission line. Since then, optical fibers have gradually occupied a more and more predominant place in the world of telecommunications, while deeply revolutionizing the field of optics by confining light in these small silica waveguides, transforming classical free-beam optics into a novel concept of wired optical circuits.

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15:52 Publié dans Science | Lien permanent | Commentaires (0)

10/06/2011

Robot programming by demonstration

sarah5090600012.jpgIf you are reading this article, it is very likely that you are interested in robots, artificial intelligence or technology-related applications. And even if this is not the case, there are chances that you use a computer more than once a week to facilitate your work (and your life in general). There is even greater chance that you do this through dedicated softwares. You may write a report, send an e-mail, check your budget on a spreadsheet, or process images from your digital camera, and doing so, you rely on existing user-friendly applications. Even if you are a programmer or know the technical details of how a computer works, you will start most of the tasks you want to achieve with the computer by opening the proper application instead of reprogramming the machine from scratch. This type of computer use seems obvious today, but at the beginning of the computer age, it was considered as obligatory and evident to be familiar with a programming language in order to make use of such a machine. From the apparition of the first personal computers, much time went by before end-users could finally do without programming skills to interact efficiently with their computers through simple (or at least quite simple) interfaces.

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08/06/2011

Défendre la démocratrie directe

2570028-check-box-with-pencil-isolated-over-white-background.jpg« Si l’on recherche en quoi consiste précisément le plus grand bien de tous, qui doit être la fin de tout système de législation, on trouvera qu’il se réduit à ces deux objets principaux, la liberté et l’égalité. La liberté, parce que toute dépendance particulière est autant de force ôtée au corps de l’Etat ; l’égalité,
parce que la liberté ne peut subsister sans elle. » Rousseau, Du contrat social (1761)

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15:41 Publié dans Politique | Lien permanent | Commentaires (0)

06/06/2011

Bio-inspired flying robots

jesselee090600059.jpgIndoor flying robots represent a largely unexplored area of robotics. There are several unmanned aerial vehicles, but these are machines that require precise information on their absolute position and can fly only in open skies far away from any object. Flying within, or among buildings requires completely different types of sensors and control strategies because geo-position information is no longer available in closed and cluttered environments. At the same time, the small space between obstacles calls for extreme miniaturization and imposes stringent constraints on energetic requirements and mechatronic design.

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15:49 Publié dans Science | Lien permanent | Commentaires (1)

03/06/2011

Corrosion and surface chemistry of metals

nejron080800152.jpgThroughout history, metals have had a decisive effect on human civilization, and they largely condition the way we live today. Electric power, combustion engines, ships, cars, railways, airplanes, production of fertilizers and pharmaceuticals, precision tools, machines, high rise buildings, sanitary systems, home appliances and even computers would not exist without metals. Corrosion and wear limit the useful lifetime of this equipment, reduce their efficiency and often affect their safety. Corrosion control and surface technology are therefore of crucial importance for our technology-based society.

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15:48 Publié dans Science | Lien permanent | Commentaires (0)

01/06/2011

La religion revient-elle sur la scène politique ?

endomedion070500010.jpgTelle est du moins l’impression véhiculée par l’observation de la campagne pour les élections aux Chambres fédérales de cet automne. Deux partis évoquent la religion, voire les valeurs chrétiennes pour se profiler par rapport à leurs concurrents. L’un, l’UDC, insiste sur le rôle du christianisme pour fonder l’identité helvétique, l’autre, le PDC,  souligne l’importance des valeurs chrétiennes pour répondre aux besoins contemporains d’avoir des points de repères. Les deux partis, fait intéressant, nient toute inféodation à une ou des Eglises. Bien au contraire, ils les renvoient à la célébration de leurs cultes et leur demandent de ne pas s’occuper de politique. En d’autres termes ils s’érigent en interprètes de la tradition religieuse helvétique.

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15:38 Publié dans Société | Lien permanent | Commentaires (0)