All articles starting with N
16,460 articles
Non-price competition
Non-price competition is rivalry among firms through any dimension other than price, including advertising, product differentiation, quality, customer service, warranties, bundling, location, and innovation, as alternatives to destructive price cuts.
Non-probability sampling
Non-probability sampling is a survey sampling approach in which units are chosen non-randomly, by convenience, judgment, or quotas, making selection probabilities unknown and inference dependent on untestable models.
Non-public network
A non-public network (NPN) is a 5G mobile network for the exclusive use of a private entity, defined by 3GPP in Release 16 and often called a private 5G network.
Non-radiative recombination
Non-radiative recombination is the annihilation of an electron–hole pair in a semiconductor without emitting a photon, wasting energy as heat and limiting solar cell voltage.
Non-randomized clinical trial
A non-randomized clinical trial assigns participants to treatment or control groups without randomization, often by usual treatment decisions or participants' choices, and estimates effects against a comparison group.
Non-rapid eye movement sleep
Non-rapid eye movement (NREM) sleep, stages N1–N3, is the non-dream-exclusive phase of sleep marked by slow waves and spindles, deep slow-wave sleep, memory consolidation, and cycles alternating with REM every 80–100 minutes.
Non-rebreather mask
Non-rebreather mask (NRM), also called reservoir mask: emergency oxygen mask with reservoir bag and one-way valves delivering 60–90% FiO2 at 12–15 L/min, with suffocation risk if the oxygen supply fails.
Non-receptor tyrosine kinases involved in cell signaling
Non-receptor tyrosine kinases (NRTKs), cytoplasmic tyrosine kinases such as Src, Abl, JAK, Tec, Syk, and FAK, relay intracellular signals; 9 major families, Src-module architecture, 26 FDA-approved inhibitors.
Non-reciprocal active matter
Non-reciprocal active matter is a branch of active-matter physics studying self-driven entities whose interactions are asymmetric, evading Newton's third law and giving rise to traveling waves, oscillations, and nonreciprocal phase transitions.
Non-reciprocal elastic metamaterials via spatiotemporal modulation
Non-reciprocal elastic metamaterials via spatiotemporal modulation are solids whose stiffness or density varies in space and time, letting elastic waves travel one way while blocked in the other.
Non-reciprocal phase transitions
Non-reciprocal phase transitions are phase transitions in many-body systems whose interactions are asymmetric, so equilibrium theory fails and new time-dependent phases with dynamically restored symmetries appear.
Non-refoulement
Non-refoulement: international law principle, rooted in Article 33 of the 1951 Refugee Convention and Article 3 CAT, prohibiting return of people to persecution, torture, or serious harm; customary norm binding all states.
Non-relativistic gravitational fields
Non-relativistic gravitational fields are descriptions of gravity where the speed of light plays no operational role, ranging from the Newtonian limit of general relativity to Newton–Cartan geometry and broader non-relativistic gravity theories.
Non-renewable resource
A non-renewable resource, also called non-renewable energy, is a natural resource, such as coal, petroleum, natural gas, uranium, and metals, that cannot be replaced within a human timescale, so using it depletes the supply.
Non-reproductive sexual behavior in animals
Non-reproductive sexual behavior in animals, also called non-conceptive or socio-sexual behavior, covers same-sex encounters, masturbation, and sex outside fertile periods, documented in over 1,500 species and explained by indiscriminate mating, social bonding, and adaptive hypotheses.
Non-repudiation
Non-repudiation, also called non-repudiability, is a security service providing evidence of who sent, signed, or received data, typically via digital signatures, so no party can deny involvement.
Non-restorative sleep
Non-restorative sleep, also called unrefreshing sleep or waking up tired, is sleep felt to be unrefreshing despite adequate duration. Dropped from ICSD-3 insomnia criteria; linked to sleep apnea, fibromyalgia, and chronic fatigue syndrome.
Non-return-to-zero
Non-return-to-zero (NRZ), or NRZ encoding, is a line code in which the signal holds one of two levels for a whole bit, changing only when the data changes.
Non-revenue water
Non-revenue water, formerly called unaccounted-for water, is water a utility puts into its distribution system but does not bill to customers, lost through leakage, illegal connections, and metering inaccuracies.
Non-rocket spacelaunch
Non-rocket spacelaunch, also called non-rocket spaceflight, is the set of proposed methods for reaching orbit without rockets, such as space elevators, skyhooks, mass drivers, and air launch.
Non-seminomatous germ cell tumor of testis
A non-seminomatous germ cell tumor of the testis (NSGCT) is a malignant testicular tumor that typically appears in the third decade of life as a painless mass.
Non-SI units mentioned in the SI
Non-SI units mentioned in the SI are units like the minute, hour, liter, tonne, and electronvolt that the SI Brochure accepts for use alongside SI units.
Non-specific autoimmune cerebellar ataxia without characteristic antibodies
Non-specific autoimmune cerebellar ataxia without characteristic antibodies, or primary autoimmune cerebellar ataxia (PACA), is suspected immune-mediated cerebellar ataxia with no known trigger or pathogenic antibody; diagnosed by 2020 task force criteria using clinical, MRI/MRS, and CSF findings.
Non-specific syndromic intellectual disability
Non-specific syndromic intellectual disability, also called complex neurodevelopmental disorder, is a rare genetic condition in which intellectual disability occurs alongside varied anomalies that do not form a defined syndrome.
Non-spiking neuron
Non-spiking neuron: a neuron signaling with graded, analog membrane potentials instead of action potentials, as in retinal rods, cones, horizontal and bipolar cells, and many invertebrate interneurons; graded synapses release transmitter continuously with ribbon zones and L-type Ca2+ channels.
Non-ST-elevation myocardial infarction
Non-ST-elevation myocardial infarction (NSTEMI) is a heart attack in which troponin confirms heart-muscle necrosis but the ECG lacks the persistent ST elevation that defines STEMI, usually from partial coronary occlusion.
Non-standalone 5G
Non-standalone 5G (5G NSA) is a 5G deployment mode that pairs new 5G radio with the existing 4G LTE core, letting operators launch 5G quickly.
Non-standard model
A non-standard model is a mathematical structure satisfying the same first-order axioms as a standard structure like the natural numbers, yet containing extra elements such as infinite integers.
Non-standard model of arithmetic
The non-standard model of arithmetic, or non-standard arithmetic, is a model of Peano Arithmetic not isomorphic to the natural numbers, containing infinite integers, first constructed by Thoralf Skolem in 1934.
Non-standard rail traction
Non-standard rail traction is railway propulsion outside the mainstream steam, diesel, and electric categories, exemplified by the French Aérotrain hovertrain, which rode on a cushion of pressurized air.