All articles starting with R
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Radhika Sarathkumar (ராதிகா சரத்குமார்)
Radhika Sarathkumar (ராதிகா சரத்குமார்), also Radikaa or Raadhika, is an Indian actress, producer, and entrepreneur in Tamil, Telugu, Kannada, Hindi, and Malayalam cinema. Debuted 1978 in Kizhakke Pogum Rail; daughter of M. R. Radha; founder of Radaan Mediaworks; National Film Award-winning producer; star of Chithi and its sequels.
Radhikaraje (રાધિકારાજે ગાયકવાડ)
Radhikaraje Gaekwad (રાધિકારાજે ગાયકવાડ), titular Maharani of Baroda, born princess of Wankaner, married Samarjitsinh Gaekwad in 2002; conserves Lukshmi Vilas Palace and revives Baroda's barodashalu textiles.
Radia Perlman
Radia Perlman is an American network engineer and computer scientist who designed the Spanning Tree Protocol, adopted as IEEE 802.1D in 1990, and the DECnet routing algorithm standardized as IS-IS.
Radial acceleration relation
The radial acceleration relation (RAR) is an empirical correlation in galaxies between observed gravitational acceleration and that predicted from visible matter, established by McGaugh, Lelli, and Schombert in 2016.
Radial arm maze
The radial arm maze is a behavioral apparatus in which a rodent collects food rewards from arms radiating from a central platform, testing spatial learning and working memory.
Radial artery
The radial artery runs from the elbow down the thumb side of the forearm to the hand, and is the standard site for feeling a pulse.
Radial basis function
A radial basis function (RBF) is a function whose value depends only on the distance from a center point, a primary tool for multivariate interpolation of scattered data and for meshless solving of partial differential equations.
Radial basis function kernel
The radial basis function (RBF) kernel, also called the Gaussian kernel, measures the similarity of two points as a decreasing function of their Euclidean distance in machine learning.
Radial basis function network
A radial basis function network is a supervised-learning model, usually a two- or three-layer neural network, whose locally tuned hidden units approximate functions for classification and time-series prediction.
Radial distribution function
The radial distribution function g(r), also called the pair distribution function, describes how particle density in a liquid varies with distance from a reference particle.
Radial engine
A radial engine is a piston engine with cylinders arranged in a circle around the crankshaft, developed for aircraft because it is light and air-cooled.
Radial extracorporeal shock wave therapy
Radial extracorporeal shock wave therapy (rESWT), also called EPAT, is a noninvasive therapy that delivers low-energy pressure waves from a pneumatic applicator to treat tendinopathies such as plantar fasciitis.
Radial gate
The radial gate, also called the Tainter gate, is a dam spillway gate with a curved upstream face that rotates on a horizontal trunnion to control water flow.
Radial glial cell
Radial glial cell (RGC), embryonic neural stem cell spanning ventricle to pia; primary progenitor generating cortical neurons and glia and scaffold for neuronal migration; transforms into astrocytes after neurogenesis.
Radial immunodiffusion
Radial immunodiffusion (RID) is a gel-based immunoassay that quantifies soluble antigens, usually proteins, by measuring the precipitin ring formed as antigen diffuses into antibody-containing gel.
Radial keratotomy
Radial keratotomy (RK), a corneal incisional refractive surgery popularized by Svyatoslav Fyodorov, corrects myopia by radial corneal cuts that flatten the central cornea; known for progressive hyperopic shift and complicated post-RK cataract IOL calculation.
Radial nerve
Radial nerve: C5–T1 terminal branch of the brachial plexus posterior cord, supplying arm and forearm extensors and dorsal hand sensation; injuries cause wrist drop, Saturday night palsy, and Wartenberg's syndrome.
Radial piston motor
A radial piston motor is a hydraulic or pneumatic motor with pistons arranged in a star formation, producing low-speed, high-torque rotation that drives winches, mixers, and wheels without a gearbox.
Radial probe endobronchial ultrasound
Radial probe endobronchial ultrasound, also known as radial EBUS, is a bronchoscopic ultrasound technique using a 20 MHz probe to localize peripheral lung lesions before biopsy.
Radial shaft seal
A radial shaft seal, also known as a lip seal or oil seal and called a Simmerring in German, seals a rotating shaft to retain lubricant and exclude contaminants.
Radial spokehead-like protein
Radial spokehead-like protein (InterPro IPR006802, Pfam PF04712) is the protein family of radial spoke head proteins RSP4/RSP6 of Chlamydomonas and homologues such as mammalian RSHL1; MORN-repeat beta-sheet proteins whose human members RSPH4A and RSPH9, when mutated, cause primary ciliary dyskinesia.
Radial tire
A radial tire, also called a radial-ply or steel-belted radial, is a pneumatic tire whose ply cords run at 90 degrees to travel under a circumferential belt.
Radial velocity
Radial velocity, also called line-of-sight velocity, is the component of an object's motion along the observer's line of sight, measured in astronomy from the Doppler shift of spectral lines.
Radial velocity method
The radial velocity method detects exoplanets by measuring periodic Doppler shifts in a star's spectral lines as the star moves under an orbiting planet's gravity.
Radian
The radian (rad) is the SI unit of plane angle, defined as the angle subtended by an arc whose length equals the radius; one radian is about 57.3 degrees.
Radian and steradian
The radian (rad) and steradian (sr) are the SI units of plane angle and solid angle, coherent derived units equal to one, reclassified from supplementary units in 1995.
Radian Capital Partners
Radian Capital Partners is a New York-based growth equity firm founded in 2016 by Jordan Bettman and Weston Gaddy, which invests in a small number of growth-stage companies.
Radian per second
The radian per second (symbol rad/s) is the coherent SI unit of angular velocity and angular frequency, differing from the hertz by a factor of 2π.
Radiance
Radiance is the radiometric measure of light power per unit projected area per unit solid angle in a given direction, measured in watts per square meter per steradian.
Radiant (manfra)
Radiant is a French manfra (manga-style comic) by Tony Valente, published by Ankama since 2013, following the sorcerer Seth against the Nemesis; first French manfra published in Japan (2015) and adapted into an NHK anime (2018–2020).