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Masayuki Inoue
Masayuki Inoue (井上 将行) is a Japanese synthetic organic chemist and professor at the University of Tokyo since 2007, best known for the 2010 total synthesis of polytheonamide B.
Mascarene High
The Mascarene High, also called the Indian Ocean subtropical high, is a semi-permanent high-pressure area over the southern Indian Ocean that drives the Asian monsoon.
Mascota Volcanic Field
The Mascota Volcanic Field is a volcanic field of cinder cones and lava domes near Mascota in Jalisco, western Mexico, hosting the youngest known minette lavas on Earth.
Mass
Mass is the property of matter that measures both its inertia, its resistance to acceleration by a force, and its participation in gravitation, measured in kilograms in the SI system.
Mass and weight conversion factors
Mass and weight conversion factors are the fixed ratios that translate quantities among units of mass, such as kilograms and pounds, and units of weight as force.
Mass attenuation coefficient
The mass attenuation coefficient, also called the mass absorption coefficient, is the linear attenuation coefficient divided by density, in cm²/g, used to calculate photon penetration and energy deposition.
Mass balance
A mass balance (material balance) is an accounting of the mass entering, leaving, accumulating in, and reacting within a system, a central tool in chemical engineering.
Mass composition of ultra-high-energy cosmic rays
The mass composition of ultra-high-energy cosmic rays describes which atomic nuclei arrive at Earth above 10^18 eV, inferred statistically from air showers since individual nuclei are destroyed in the atmosphere.
Mass concentration
Mass concentration is the mass of a constituent divided by the volume of the mixture, symbolized γ or ρ and measured in kilograms per cubic meter.
Mass defect
The mass defect is the difference between an atomic nucleus's mass and the sum of its free protons and neutrons; it equals the nuclear binding energy.
Mass diffusivity
Mass diffusivity, also called the diffusion coefficient, is the proportionality constant D in Fick's first law, with units of m²/s, that measures how fast a species spreads through a medium by random molecular motion.
Mass flow rate
Mass flow rate is the mass of fluid passing a conduit cross-section per unit time, written ṁ and measured in kilograms per second in SI units.
Mass flow sensor
A mass flow sensor, also called a mass flow meter or MAF sensor, measures the rate of fluid mass flow directly, without separate pressure or temperature measurements.
Mass fraction (chemistry)
Mass fraction, also known as mass percent or weight percent, is the mass of a constituent of a mixture divided by the total mass of the mixture.
Mass in special relativity
Mass in special relativity, sometimes called relativistic mass in older texts, is the invariant quantity every observer agrees on, related to energy and momentum by E² = (pc)² + (mc²)².
Mass inflation
Mass inflation is an instability inside realistic black holes, named by Eric Poisson and Werner Israel in 1989, in which the internal mass parameter grows without classical bound near the Cauchy horizon.
Mass number
The mass number, also called the nucleon number, is the total count of protons and neutrons in an atomic nucleus, written as a superscript before the element symbol.
Mass photometry
Mass photometry, introduced in 2018 as interferometric scattering mass spectrometry (iSCAMS), is a label-free optical method that measures single biomolecule masses in solution in minutes.
Mass ratio
A mass ratio is the quotient of the mass of one constituent of a system by the mass of another, a dimensionless quantity used across chemistry and rocketry.
Mass segregation (astronomy)
Mass segregation in astronomy is the tendency of the most massive stars in a star cluster to occupy a more centrally concentrated distribution than lower-mass stars.
Mass spectrometry
Mass spectrometry, also known as mass spectroscopy or MS, is an analytical technique that measures the mass-to-charge ratio of ions to identify and quantify the chemical species in a sample.
Mass spectrometry imaging
Mass spectrometry imaging (MSI) is a label-free analytical technique that maps the spatial distribution of molecules across a sample, with each image pixel holding a full mass spectrum.
Mass transfer
Mass transfer is the flow of matter from one star in a binary system to its companion, occurring when the donor fills its Roche lobe and gas escapes through the L1 point.
Mass versus weight
Mass versus weight is the distinction between mass, the fixed quantity of matter in an object, and weight, the gravitational force on it, which varies with location.
Mass wasting
Mass wasting, also called mass movement, is the downslope movement of rock and soil under gravity alone, ranging from slow creep to debris avalanches reaching 400 km/h.
Mass-independent fractionation
Mass-independent fractionation is isotope fractionation in which isotope ratios do not follow mass laws, discovered in ozone chemistry in 1983 and used in meteorites, paleoclimatology, and atmospheric science.
Mass-sheet degeneracy
The mass-sheet degeneracy (MSD) is a gravitational lensing invariance found by Falco, Gorenstein, and Shapiro in 1985: adding a uniform mass sheet changes only image time delays.
Mass-to-charge ratio
The mass-to-charge ratio, abbreviated m/z, is a dimensionless quantity used to characterize ions in mass spectrometry, defined by IUPAC as mass number divided by charge number.
Mass-to-light ratio
The mass-to-light ratio (M/L) is the mass of a galaxy or galaxy cluster divided by its light, a diagnostic of unseen dark matter first applied by Fritz Zwicky in 1933.
Mass–energy equivalence
Mass–energy equivalence, also known as E equals mc squared, is the physics principle that mass and energy are the same quantity, stated by Einstein in 1905.