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François Cosserat
François Cosserat (1852–1914) was a French engineer and mathematician known by his theories about deformable bodies written with his brother Eugène. Life and work François Cosserat was the eldest of the three sons of François-Constant Cosserat, a textile manufacturer in Amiens. The three sons achieved to study in one of the ''grandes écoles'' of Paris. François studied at the École Polytechnique from 1870 to 1872 and then in the École Nationale des Ponts et Chaussées until 1875. François Cosserat followed a typical career as civil engineer in the French East Railroad Company constructing and designing bridges, tunnels, etc. In 1895 he became chief engineer. Besides his engineer career he worked with his junior brother, Eugène, in mechanics and elasticity, publishing papers and a book about it. In 1913 he was elected president of the Société mathématique de France. His most important work is his book, a joint work with his brother, Théorie des corps déforma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douai
Douai (, , ,; pcd, Doï; nl, Dowaai; formerly spelled Douay or Doway in English) is a city in the Nord département in northern France. It is a sub-prefecture of the department. Located on the river Scarpe some from Lille and from Arras, Douai is home to one of the region's most impressive belfries. History Its site probably corresponds to that of a 4th-century Roman fortress known as Duacum. From the 10th century, the town was a romance fiefdom of the counts of Flanders. The town became a flourishing textile market centre during the Middle Ages, historically known as Douay or Doway in English. In 1384, the county of Flanders passed into the domains of the Dukes of Burgundy and thence in 1477 into Habsburg possessions. In 1667, Douai was taken by the troops of Louis XIV of France, and by the 1668 Treaty of Aix-la-Chapelle, the town was ceded to France. During successive sieges from 1710 to 1712, Douai was almost completely destroyed by the British Army. By 1713, the town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasticity (physics)
In physics and materials science, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate loads are applied to them; if the material is elastic, the object will return to its initial shape and size after removal. This is in contrast to ''plasticity'', in which the object fails to do so and instead remains in its deformed state. The physical reasons for elastic behavior can be quite different for different materials. In metals, the atomic lattice changes size and shape when forces are applied (energy is added to the system). When forces are removed, the lattice goes back to the original lower energy state. For rubbers and other polymers, elasticity is caused by the stretching of polymer chains when forces are applied. Hooke's law states that the force required to deform elastic objects should be directly proportional to the distance of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1852 Births
Year 185 ( CLXXXV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Lascivius and Atilius (or, less frequently, year 938 '' Ab urbe condita''). The denomination 185 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Nobles of Britain demand that Emperor Commodus rescind all power given to Tigidius Perennis, who is eventually executed. * Publius Helvius Pertinax is made governor of Britain and quells a mutiny of the British Roman legions who wanted him to become emperor. The disgruntled usurpers go on to attempt to assassinate the governor. * Tigidius Perennis, his family and many others are executed for conspiring against Commodus. * Commodus drains Rome's treasury to put on gladiatorial spectacles and confiscates property to su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19th-century French Mathematicians
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under colonial rule. It was also marked by the collapse of the large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noether's Theorem
Noether's theorem or Noether's first theorem states that every differentiable symmetry of the action of a physical system with conservative forces has a corresponding conservation law. The theorem was proven by mathematician Emmy Noether in 1915 and published in 1918. The action of a physical system is the integral over time of a Lagrangian function, from which the system's behavior can be determined by the principle of least action. This theorem only applies to continuous and smooth symmetries over physical space. Noether's theorem is used in theoretical physics and the calculus of variations. It reveals the fundamental relation between the symmetries of a physical system and the conservation laws. It also made modern theoretical physicists much more focused on symmetries of physical systems. A generalization of the formulations on constants of motion in Lagrangian and Hamiltonian mechanics (developed in 1788 and 1833, respectively), it does not apply to systems that cann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Point Method
The material point method (MPM) is a numerical technique used to simulate the behavior of solids, liquids, gases, and any other continuum material. Especially, it is a robust spatial discretization method for simulating multi-phase (solid-fluid-gas) interactions. In the MPM, a continuum body is described by a number of small Lagrangian elements referred to as 'material points'. These material points are surrounded by a background mesh/grid that is used to calculate terms such as the deformation gradient. Unlike other mesh-based methods like the finite element method, finite volume method or finite difference method, the MPM is not a mesh based method and is instead categorized as a meshless/meshfree or continuum-based particle method, examples of which are smoothed particle hydrodynamics and peridynamics. Despite the presence of a background mesh, the MPM does not encounter the drawbacks of mesh-based methods (high deformation tangling, advection errors etc.) which makes it a promisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscope
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuum Robot
A continuum robot is a type of robot that is characterised by infinite degrees of freedom and number of joints. These characteristics allow continuum manipulators to adjust and modify their shape at any point along their length, granting them the possibility to work in confined spaces and complex environments where standard rigid-link robots cannot operate. In particular, we can define a continuum robot as an actuatable structure whose constitutive material forms curves with continuous tangent vectors. This is a fundamental definition that allows to distinguish between continuum robots and snake-arm robots or hyper-redundant manipulators: the presence of rigid links and joints allows them to only approximately perform curves with continuous tangent vectors. The design of continuum robots is bioinspired, as the intent is to resemble biological trunks, snakes and tentacles. Several concepts of continuum robots have been commercialised and can be found in many different domains of appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Metamaterial
Mechanical metamaterials are artificial structures with mechanical properties defined by their structure rather than their composition. They can be seen as a counterpart to the rather well-known family of optical metamaterials. They are often also termed ''elastodynamic metamaterials'' and include acoustic metamaterials as a special case of vanishing shear. Their mechanical properties can be designed to have values which cannot be found in nature. Examples of mechanical metamaterials Acoustic / phononic metamaterials Acoustic or phononic metamaterials can exhibit acoustic properties not found in nature, such as negative effective bulk modulus, negative effective mass density, or double negativity. They find use in (mostly still purely scientific) applications like acoustic subwavelength imaging, superlensing, negative refraction or transformation acoustics. Materials with negative Poisson's ratio (auxetics) Poisson's ratio defines how a material expands (or contracts) t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Société Mathématique De France
Lactalis is a French multinational dairy products corporation, owned by the Besnier family and based in Laval, Mayenne, France. The company's former name was Besnier SA. Lactalis is the largest dairy products group in the world, and is the second largest food products group in France, behind Danone. It owns brands such as Parmalat, Président, Siggi's Dairy, Skånemejerier, Rachel's Organic, and Stonyfield Farm. History André Besnier started a small cheesemaking company in 1933 and launched its ''Président'' brand of Camembert in 1968. In 1990, it acquired Group Bridel (2,300 employees, 10 factories, fourth-largest French dairy group) with a presence in 60 countries. In 1992, it acquired United States cheese company Sorrento. In 1999, ''la société Besnier'' became ''le groupe Lactalis'' owned by Belgian holding company BSA International SA. In 2006, they bought Italian group Galbani, and in 2008, bought Swiss cheesemaker Baer. They bought Italian group Parmalat in a 2011 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
