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Q-system (geotechnical Engineering)
: ''For the linguistics formalism, see Q-systems.'' : ''For the genetic method, see Q-system (genetics).'' The Q-system for rock mass classification is developed by Barton, Lien, and Lunde. It expresses the quality of the rock mass in the so-called ''Q-value'', on which design are based and support recommendations for underground excavations. The Q-value is determined with ::Q=\frac \times \frac \times \frac The first term '' RQD'' ''(Rock Quality Designation)'' divided by ''Jn (joint set number)'' is related to the size of the intact rock blocks in the rock mass. The second term ''Jr (joint roughness number)'' divided by ''Ja (joint alteration number)'' is related to the shear strength along the discontinuity planes and the third term ''Jw (joint water parameter)'' divided by ''SRF (stress reduction factor)'' is related to the stress environment on the intact rock blocks and discontinuities around the underground excavation. A multiplication of the three terms results in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-systems
Q-systems are a method of directed graph transformations according to given grammar rules, developed at the Université de Montréal by Alain Colmerauer in 1967–70 for use in natural language processing. The Université de Montréal's machine translation system, TAUM system, TAUM-73, used the Q-Systems as its language formalism. The data structure manipulated by a Q-system is a Q-graph, which is a directed acyclic graph with one entry node and one exit node, where each arc bears a labelled ordered tree. An input sentence is usually represented by a linear Q-graph where each arc bears a word (tree reduced to one node labelled by this word). After analysis, the Q-graph is usually a bundle of 1-arc paths, each arc bearing a possible analysis tree. After generation, the goal is usually to produce as many paths as desired outputs, with again one word per arc. A Q-System consists of a sequence of Q-treatments, each being a set of Q-rules, of the form []. The Q-treatments are appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-system (genetics)
Q-system is a genetic tool that allows to express transgenes in a living organism. Originally the Q-system was developed for use in the vinegar fly ''Drosophila melanogaster'', and was rapidly adapted for use in cultured mammalian cells, zebrafish, worms and mosquitoes. The Q-system utilizes genes from the ''qa'' cluster of the bread fungus ''Neurospora crassa'', and consists of four components: the transcriptional activator (QF/QF2/QF2w), the enhancer QUAS, the repressor QS, and the chemical de-repressor quinic acid. Similarly to GAL4/UAS and LexA/LexAop, the Q-system is a binary expression system that allows to express reporters or effectors (e.g. fluorescent proteins, ion channels, toxins and other genes) in a defined subpopulation of cells with the purpose of visualising these cells or altering their function. In addition, GAL4/UAS, LexA/LexAop and the Q-system function independently of each other and can be used simultaneously to achieve a desired pattern of reporter expre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Quality Designation
Core recovery parameters describe the quality of core recovered from a borehole. Total core recovery Total core recovery (TCR) is the borehole core recovery percentage. TCR is defined as the quotient: :TCR = \left(\frac\right)\times 100 % :l_\mathrm = Sum of length of core pieces :l_\mathrm = Total length of core run Solid core recovery Solid core recovery (SCR) is the borehole core recovery percentage of solid, cylindrical, pieces of rock core. SCR is defined as the quotient: :SCR = \left(\frac\right)\times 100 % :l_ = Sum of length of solid, cylindrical, core pieces :l_ = Total length of core run Rock quality designation Rock-quality designation (RQD) is a rough measure of the degree of jointing or fracture in a rock mass, measured as a percentage of the drill core in lengths of 10 cm or more. High-quality rock has an RQD of more than 75%, low quality of less than 50%. Rock quality designation (RQD) has several definitions. The most widely used definition was developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Structure Rating
Rock Structure Rating (RSR) is a quantitative method for describing quality of a rock mass and appropriate ground support, in particular, for steel-rib support, developed by Wickham, Tiedemann and Skinner. The RSR concept introduced a rating system for rock masses. It was the sum of weighted values in this classification system. There are considered two general categories: *geotechnical parameters: :rock type; joint pattern; joint orientations; type of discontinuities; major faults; shears and folds; rock material properties; weathering or alteration. and *construction parameters: :size of tunnel; direction of drive; method of excavation. The RSR value of any tunnel section is obtained by summing the weighted numerical values determined for each parameter. The RSR concept is a very useful method for selecting steel rib support for rock tunnels. As with any empirical approach one should not apply the concept beyond the range of the sufficient and reliable data used for develop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Mass Rating
The rock mass rating (RMR) is a geomechanics, geomechanical classification system for Rock (geology), rocks, developed by Z. T. Bieniawski between 1972 and 1973. Since then it has undergone multiple modifications out of which, RMR89 is commonly used. Recently RMR14 has been proposed to improve the RMR performance by incorporating new experiences from tunnel practices. Continuous functions and a software "QuickRMR" for RMR89 and RMR14 have also been proposed by Kundu.Kundu, J., Sarkar, K., Singh, A.K., & Singh, T., 2020. Continuous functions and a computer application for rock mass rating. Int. J. Rock Mech. Min. Sci. 129. RMR combines the most significant geologic parameters of influence and represents them with one overall comprehensive index of rock mass quality, which is used for the design and construction of excavations in rock, such as tunnels, mines, slopes, and foundations. Definition The following six parameters are used to classify a rock mass using the RMR system #Uniax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASTM International
ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. Some 12,575 ASTM voluntary consensus standards operate globally. The organization's headquarters is in West Conshohocken, Pennsylvania, about northwest of Philadelphia. It is founded in 1902 as the American Section of the International Association for Testing Materials (see also International Organization for Standardization). History A group of scientists and engineers, led by Charles Dudley, formed ASTM in 1898 to address the frequent rail breaks affecting the fast-growing railroad industry. The group developed a standard for the steel used to fabricate rails. Originally called the "American Society for Testing Materials" in 1902, it became the "American Society for Testing And Materials" in 1961. In 2001, ASTM official ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taylor & Francis
Taylor & Francis Group is an international company originating in England that publishes books and academic journals. Its parts include Taylor & Francis, Routledge, F1000 (publisher), F1000 Research or Dovepress. It is a division of Informa, Informa plc, a United Kingdom–based publisher and conference company. Overview The company was founded in 1852 when William Francis (chemist), William Francis joined Richard Taylor (editor), Richard Taylor in his publishing business. Taylor had founded his company in 1798. Their subjects covered agriculture, chemistry, education, engineering, geography, law, mathematics, medicine, and social sciences. Francis's son, Richard Taunton Francis (1883–1930), was sole partner in the firm from 1917 to 1930. In 1965, Taylor & Francis launched Wykeham Publications and began book publishing. T&F acquired Hemisphere Publishing in 1988, and the company was renamed Taylor & Francis Group to reflect the growing number of Imprint (trade name), imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springer Science+Business Media
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second largest academic publisher with 65 staff in 1872.Chronology ". Springer Science+Business Media. In 1964, Springer expanded its business internationally, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Society Of Civil Engineers
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISRM
The International Society for Rock Mechanics - ISRM was founded in Salzburg in 1962 as a result of the enlargement of the "Salzburger Kreis". Its foundation is mainly owed to Prof. Leopold Müller who acted as President of the Society until September 1966. The ISRM is a non-profit scientific association supported by the fees of the members and grants that do not impair its free action. In 2021 the Society had 6,800 members and 49 National Groups. The field of Rock Mechanics is taken to include all studies relative to the physical and mechanical behaviour of rocks and rock masses and the applications of this knowledge for the better understanding of geological processes and in the fields of Engineering. The main objectives and purposes of the Society are: * to encourage international collaboration and exchange of ideas and information between Rock Mechanics practitioners; * to encourage teaching, research, and advancement of knowledge in Rock Mechanics; * to promote high standards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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