Rheology is the study of the flow of matter in a liquid state, but as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force. Rheology is the science of flow within a material, it is a branch of physics which deals with the deformation and flow of materials, both solids and liquids. The term rheology was coined by Eugene C. Bingham, a professor at Lafayette College, in 1920, from a suggestion by a colleague, Markus Reiner; the term was inspired by the aphorism of Simplicius, panta rhei, "everything flows", was first used to describe the flow of liquids and the deformation of solids. It applies to substances that have a complex microstructure, such as muds, suspensions and other glass formers, as well as many foods and additives, bodily fluids and other biological materials, other materials that belong to the class of soft matter such as food. Newtonian fluids can be characterized by a single coefficient of viscosity for a specific temperature.
Although this viscosity will change with temperature, it does not change with the strain rate. Only a small group of fluids exhibit such constant viscosity; the large class of fluids whose viscosity changes with the strain rate are called non-Newtonian fluids. Rheology accounts for the behavior of non-Newtonian fluids, by characterizing the minimum number of functions that are needed to relate stresses with rate of change of strain or strain rates. For example, ketchup can have its viscosity reduced by shaking. Ketchup is a shear-thinning material, like yogurt and emulsion paint, exhibiting thixotropy, where an increase in relative flow velocity will cause a reduction in viscosity, for example, by stirring; some other non-Newtonian materials show the opposite behavior, rheopecty: viscosity increasing with relative deformation, are called shear-thickening or dilatant materials. Since Sir Isaac Newton originated the concept of viscosity, the study of liquids with strain-rate-dependent viscosity is often called Non-Newtonian fluid mechanics.
The experimental characterisation of a material's rheological behaviour is known as rheometry, although the term rheology is used synonymously with rheometry by experimentalists. Theoretical aspects of rheology are the relation of the flow/deformation behaviour of material and its internal structure, the flow/deformation behaviour of materials that cannot be described by classical fluid mechanics or elasticity. In practice, rheology is principally concerned with extending continuum mechanics to characterize flow of materials, that exhibits a combination of elastic and plastic behavior by properly combining elasticity and fluid mechanics, it is concerned with establishing predictions for mechanical behavior based on the micro- or nanostructure of the material, e.g. the molecular size and architecture of polymers in solution or the particle size distribution in a solid suspension. Materials with the characteristics of a fluid will flow when subjected to a stress, defined as the force per area.
There are different sorts of stress and materials can respond differently under different stresses. Much of theoretical rheology is concerned with associating external forces and torques with internal stresses and internal strain gradients and flow velocities. Rheology unites the unrelated fields of plasticity and non-Newtonian fluid dynamics by recognizing that materials undergoing these types of deformation are unable to support a stress in static equilibrium. In this sense, a solid undergoing plastic deformation is a fluid, although no viscosity coefficient is associated with this flow. Granular rheology refers to the continuum mechanical description of granular materials. One of the major tasks of rheology is to empirically establish the relationships between strains and stresses, by adequate measurements, although a number of theoretical developments are required before using the empirical data; these experimental techniques are known as rheometry and are concerned with the determination with well-defined rheological material functions.
Such relationships are amenable to mathematical treatment by the established methods of continuum mechanics. The characterization of flow or deformation originating from a simple shear stress field is called shear rheometry; the study of extensional flows is called extensional rheology. Shear flows are much easier to study and thus much more experimental data are available for shear flows than for extensional flows. Fluid and solid character are relevant at long times:We consider the application of a constant stress: if the material, after some deformation resists further deformation, it is considered a solid if, by contrast, the material flows indefinitely, it is considered a fluid By contrast and viscous behaviour is relevant at short times:We again consider the application of a constant stress:if the material deformation strain increases linearly with increasing applied stress the material
"GNCC" redirects here. For the off-road racing series, see Grand National Cross Country; the Grand National Curling Club known as the GNCC, is the union of curling clubs in New England and the Mid-Atlantic of the United States. It was established in 1867. In recent years, the GNCC's territory has expanded to include clubs in the Southeast; as of 2019, it includes 69 clubs in seventeen states, including Alabama, Delaware, Georgia, Maryland, New Hampshire, New Jersey, New York, North Carolina, Rhode Island, South Carolina and Virginia. In response to a May 1867 advertisement in The Scottish-American Journal, 33 delegates from seven clubs from across the U. S. met on June 1867 in the Caledonian Club rooms in New York City. The seven original clubs were: Caledonian Club New York Club Thistle Club St. Andrew's Club Patterson Club Caledonian Club Burns Club Rather than join the Royal Caledonian Curling Club in Scotland, the delegates decided to form a national organization. On a motion by Mr. James Brand, New York, the new club was called the "Grand National Curling Club of America" and became the first national curling organization in America.
Within a few months, additional clubs joined the GNCC from Michigan, New Jersey, New York and Pennsylvania. The earliest documented club in the current GNCC geographic area was the New England Curling Club of Boston, established sometime prior to 1839; these events are GNCC Sponsored Events, do not include the events that are sponsored by the GNCC Member Clubs. Men's Francis Dykes Bonspiel Ross Tarlton Senior Men’s Gordon International Gordon-Emmett – The oldest consecutive event in North America. Women's Elisabeth Childs Challenge Mixed/Open Senior Mixed Ray Kayser Memorial Bonspiel Arena Club Championship In 2018, the GNCC implemented a "New Management Plan"; this reorganized its leadership positions. As part of this change, the highest-ranked officer of the GNCC is now "Chairman of the Board of Directors", eliminating the position of "President". Grand National Curling Club
Zhou Zhi-Hua is a Professor of Computer Science at Nanjing University. He is the Standing Deputy Director of the National Key Laboratory for Novel Software Technology, Founding Director of the LAMDA Group, his research interests include machine learning and data mining. Zhou Zhi-Hua received his B. Sc. M. Sc. and Ph. D. degrees in computer science from Nanjing University in 1996, 1998 and 2000 all with the highest honor. He joined the Department of Computer Science & Technology of Nanjing University as an Assistant Professor in 2001, promoted to Associate Professor in 2002 and Full Professor in 2003, he was appointed as Cheung Kong Professor in 2006. Zhou is known for significant contributions to ensemble learning, multi-label learning, learning with partial supervision, he has authored two books and published more than 150 scientific articles in premium journals/conferences. According to Google Scholar, his h-index is 74, he holds 18 patents. Zhou founded the ACML, served as Advisory Committee member of IJCAI, General co-chair of ICDM'2016, Program Committee Co-Chair of IJCAI'2015 Machine Learning track, etc.
He served for editorial boards of many journals, including Executive Editor-in-Chief for Frontiers of Computer Science. He is/was Chair of CCF-AI, Chair of the IEEE CIS Data Mining Technical Committee, Chair of the CAAI Machine Learning Technical Committee, he founded a famous research group in machine learning and data mining in China. Zhou received various award/honors including the National Natural Science Award of China, the IEEE ICDM Outstanding Service Award, the PAKDD Distinguished Contribution Award, the IEEE CIS Outstanding Early Career Award, the Microsoft Professorship Award, etc, he is a Fellow of the ACM, AAAS, AAAI, IEEE, IAPR,IET/IEE and CCF. Ensemble Methods: Foundations and Algorithms. 2012 Machine Learning.. 2016 Zhi-Hua Zhou homepage Zhi-Hua Zhou publications indexed by Google Scholar