Research Tool Patents and Free-Libre Biotechnology: A Unified Perspective.

This paper proposes a unified conceptual framework to analyse the multiple role and consequences of patents in the case of biotechnology research tools. We argue that the knowledge/information and independent/complementary nature of research tools define heterogeneous frameworks in which the patent system plays different roles. In particular, using the analogy with the free-libre open source movement in software, we show that patents can promote open innovation by ensuring the freedom of some pieces of knowledge. A strong conclusion of the paper is therefore that, against common belief, an adequate use of the patent system may contribute to preserving freedom of access to upstream research tools within a framework that we call free-libre biotechnology.Intellectual property rights, sequential innovation, open source, life science, collective invention.

Weak gravitational lensing of finite beams

The standard theory of weak gravitational lensing relies on the infinitesimal light beam approximation. In this context, images are distorted by convergence and shear, the respective sources of which unphysically depend on the resolution of the distribution of matter---the so-called Ricci-Weyl problem. In this letter, we propose a strong-lensing-inspired formalism to describe the lensing of finite beams. We address the Ricci-Weyl problem by showing explicitly that convergence is caused by the matter enclosed by the beam, regardless of its distribution. Furthermore, shear turns out to be systematically enhanced by the finiteness of the beam. This implies, in particular, that the Kaiser-Squires relation between shear and convergence is violated, which could have profound consequences on the interpretation of weak lensing surveys.Comment: 6 pages, 2 figures, v2: matches published version, some typos correcte

The theory of stochastic cosmological lensing

On the scale of the light beams subtended by small sources, e.g. supernovae, matter cannot be accurately described as a fluid, which questions the applicability of standard cosmic lensing to those cases. In this article, we propose a new formalism to deal with small-scale lensing as a diffusion process: the Sachs and Jacobi equations governing the propagation of narrow light beams are treated as Langevin equations. We derive the associated Fokker-Planck-Kolmogorov equations, and use them to deduce general analytical results on the mean and dispersion of the angular distance. This formalism is applied to random Einstein-Straus Swiss-cheese models, allowing us to: (1) show an explicit example of the involved calculations; (2) check the validity of the method against both ray-tracing simulations and direct numerical integrations of the Langevin equation. As a byproduct, we obtain a post-Kantowski-Dyer-Roeder approximation, accounting for the effect of tidal distortions on the angular distance, in excellent agreement with numerical results. Besides, the dispersion of the angular distance is correctly reproduced in some regimes.Comment: 37+13 pages, 8 figures. A few typos corrected. Matches published versio

Multi-physic system simplification method applied to a helicopter flight axis active control

A helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool: the Energetic Macroscopic Representation. Elements of the system are mainly composed of passive technologies and their number tends to increase year after year to improve the pilots comfort by adding new functions. A new methodology is proposed to transform the system into a new active one by replacing some hydro-mechanical elements by a new controllable active mechanical source. The challenge is to simplify the flight control architecture while preserving the global behaviour of the system

Modeling Stiffness and Damping in Rotational Degrees of Freedom Using Multibond Graphs

A contribution is proposed for the modeling of mechanical systems using multibond graphs. When modeling a physical system, it may be needed to catch the dynamic behavior contribution of the joints between bodies of the system and therefore to characterize the stiffness and damping of the links between them. The visibility of where dissipative or capacitive elements need to be implemented to represent stiffness and damping in multibond graphs is not obvious and will be explained. A multibond graph architecture is then proposed to add stiffness and damping in hree rotational degrees of freedom. The resulting joint combines the spherical joint multibond graph relaxed causal constraints while physically representing three concatenated revolute joints. The mathematical foundations are presented, and then illustrated through the modeling and simulation of an inertial navigation system; in which stiffness and damping between the gimbals are taken into account. This method is particularly useful when modeling and simulating multibody systems using Newton-Euler formalism in multibond graphs. Future work will show how this method can be extended to more complex systems such as rotorcraft blades' connections with its rotor hub.Fondation Airbus Grou

Policies and Deployment for Fuel Cell Electric Vehicles An Assessment of the Normandy Project

The paper provides a cost benefit analysis of one of the most prominent deployment project in France of fuel cell electric vehicles, taking place in Normandy. The project builds on the substitution of a diesel Renault Kangoo by an electric Renault Kangoo ZE with afuel cell range extender for public fleets. The analysis points out potential weaknesses of the project as it is envisioned today using a decomposition of the value-chain. To achieve sustainability in 2025 a much stronger deployment should take place. This would allow for a sharp decrease in the total cost of ownership thanks to a close coordination between hydrogen production and its delivery through refilling stations to take advantage of the expected increasing volume of hydrogen consumption along the deployment path. Thissuggests that a high level in public funds at this early deployment phase can be critical for the success of the project

New sol-gel formulations to increase the barrier effect of a protective coating against the corrosion of steels

Films were deposited onto AISI 430 stainless steel substrates by dip-coating technique. The aim is to reach the AISI 304L stainless steel anti-corrosion properties by a coated AISI 430 stainless steel system. Sol formulation is done from the starting precursors tetraethylorthosilicate (TEOS) and 3(trimethoxysilyl) propyl methacrylate (MAP). After the hydrolysis of these precursors, sol-gel reactions occur before the addition (or not) of a controlled quantity of cerium nitrate. The addition of the PEG (polyethylene glycol), used as plasticizer has been studied in this paper and both physical and chemical properties of the synthesized hybrid films were studied by varying PEG ratios. Based on SEM observations and mass gain measurements, the thickness of the films has been adjustable. Another parameter plays a key role: the drying step of the whole system. It has been investigated and optimized in this paper to lead to coatings with a high barrier effect. The efficiency of the anti-corrosion protection of hybrid-coated stainless steel was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) after immersion of the material in a 3.5% NaCl solution. Double-layered systems were successfully developed and a good compromise between PEG content and drying conditions has been found. Potentiodynamic polarization curves showed that the hybrid coating prepared using a TEOS/MAP/PEG yielded the best anti-corrosion performances. It acts as an efficient barrier similar to AISI 304 stainless steel used as reference, increasing the total impedance and significantly reducing the current densities

Flexible fiber batteries for applications in smart textiles

Here we discuss two alternative approaches for building flexible batteries for applications in smart textiles. The first approach uses well-studied inorganic electrochemistry (Al-NaOCl galvanic cell) and innovative packaging in order to produce batteries in a slender and flexible fiber form that can be further weaved directly into the textiles. During fabrication process the battery electrodes are co-drawn within a microstructured polymer fiber, which is later filled with liquid electrolyte. The second approach describes Li-ion chemistry within solid polymer electrolytes that are used to build a fully solid and soft rechargeable battery that can be furthermore stitched onto a textile, or integrated as stripes during weaving process