All articles starting with N
16,460 articles
Nuclear program of Iran
Iran's nuclear program (برنامه هستهای ایران), started in 1957 with US Atoms for Peace help, spans Bushehr power reactors, uranium enrichment at Natanz and Fordow, the 2015 JCPOA, its 2018 collapse, and the 2025 war and IAEA access loss.
Nuclear program of Saudi Arabia
Saudi Arabia's civilian nuclear program: K.A.CARE, NRRC regulator, SNEHC operator, Duwaiheen tender for two 1.4 GWe reactors with CNNC, EDF, KEPCO, Rosatom bidding, no reactor built, SQP rescinded 2024, no Additional Protocol.
Nuclear proliferation
Nuclear proliferation is the spread of nuclear weapons and weapons-relevant technology to additional states. Key facts: NPT of 1968 with 190 parties, nine nuclear-armed states, four reversed arsenals, and post-2022 arms control erosion.
Nuclear propulsion
Nuclear propulsion is the use of a reactor to supply vehicle energy. It is used in mature naval systems like submarines since the 1950s and in developing spacecraft applications.
Nuclear pulse propulsion
Nuclear pulse propulsion is a proposed spacecraft propulsion method in which small nuclear explosions behind a vehicle push a plate, developed as Project Orion from 1958 to 1965 and never flown.
Nuclear quadrupole resonance
Nuclear quadrupole resonance (NQR) is a radio-frequency spectroscopic technique for rigid solids, related to NMR but requiring no external magnetic field, first observed in 1949.
Nuclear quadrupole resonance spectroscopy
Nuclear quadrupole resonance (NQR) spectroscopy is a radio-frequency technique for solids, often called zero-field NMR, discovered in 1949 and used to detect explosives, narcotics, and landmines, and to analyze pharmaceuticals.
Nuclear quantum effects in water
Nuclear quantum effects in water arise from zero-point energy, delocalization, and tunneling of protons, measurably altering the structure, dynamics, and spectroscopy of liquid water, ice, and aqueous interfaces.
Nuclear reaction
A nuclear reaction, also called a nuclear process, occurs when an incoming particle such as a proton, neutron, or alpha particle collides with an atomic nucleus and produces different nuclei.
Nuclear reaction analysis
Nuclear reaction analysis (NRA) is an ion beam analysis method that directs MeV ions at a solid and detects nuclear reaction products to profile light elements like hydrogen and lithium.
Nuclear reactor
A nuclear reactor, also called an atomic reactor, is a machine that controls a nuclear chain reaction to generate heat, producing about 9% of the world's electricity.
Nuclear receptor
Nuclear receptors (NRs) are ligand-activated transcription factors, 48 in humans, that bind steroids, thyroid hormone, vitamin D, retinoic acid, and fatty acids, bind DNA at hormone response elements, and are targets for 15–20% of drugs.
Nuclear receptor coactivator
Nuclear receptor coactivator: a protein that binds hormone-activated nuclear receptors via LXXLL motifs and boosts target-gene transcription; first member SRC-1, p160 SRC family of three, over 400 coregulators known.
Nuclear receptor corepressor
Nuclear receptor corepressor, also known as NCoR or NCOR1, is a large transcriptional corepressor protein, cloned in 1995, that binds unliganded nuclear receptors and represses target genes by recruiting HDAC3-containing complexes.
Nuclear Regulation Authority
The Nuclear Regulation Authority (Genshiryoku Kisei Iinkai, abbreviated NRA) is Japan's independent nuclear regulatory body, created in 2012 as an external organ of the Ministry of the Environment after Fukushima.
Nuclear Regulatory Commission
The Nuclear Regulatory Commission is the independent US agency that licenses and regulates civilian nuclear power plants and radioactive materials, taking over from the Atomic Energy Commission in 1975.
Nuclear renaissance
The nuclear renaissance is the renewed interest in building nuclear power plants since the early 2000s, driven by climate policy, energy security, and rising electricity demand.
Nuclear reprocessing
Nuclear reprocessing is the set of chemical processes, chiefly PUREX, that separate usable uranium and plutonium from spent nuclear reactor fuel so they can be recycled into new fuel.
Nuclear resonance
A nuclear resonance is a quasi-stationary energy level of a compound nucleus that appears as a sharp peak in the reaction cross section at discrete projectile energies.
Nuclear resonance scattering
Nuclear resonance scattering (NRS) is a family of X-ray spectroscopy techniques in which synchrotron radiation excites narrow nuclear resonances in Mössbauer isotopes, first demonstrated at Hamburg in 1985.
Nuclear rotation
Nuclear rotation is the collective, quantized rotation of an atomic nucleus as a whole, occurring in deformed nuclei such as the rare-earth (mass 150–190) and actinide regions.
Nuclear run-on assay
The nuclear run-on assay is a molecular biology technique measuring active gene transcription by letting isolated nuclei extend initiated transcripts with labeled nucleotides, independent of RNA stability.
Nuclear safeguards
Nuclear safeguards are verification measures, applied chiefly by the International Atomic Energy Agency, by which states demonstrate that nuclear material stays in peaceful use and is not diverted to weapons.
Nuclear Safety Commission of Spain
The Nuclear Safety Commission of Spain (Consejo de Seguridad Nuclear, CSN) is Spain's independent regulator for nuclear safety and radiation protection, created by law in 1980.
Nuclear Safety Directive
The Nuclear Safety Directive, adopted in 2009 and amended in 2014, is binding EU law obliging Member States to maintain nuclear safety frameworks, independent regulators, and peer reviews.
Nuclear salt-water rocket
The nuclear salt-water rocket (NSWR) is a proposed rocket propulsion concept by Robert Zubrin in 1991, fissioning dissolved uranium salt for high thrust and specific impulse.
Nuclear scattering theory
Nuclear scattering theory is the framework describing elastic and inelastic scattering of neutrons and protons by nuclei, built on partial-wave analysis, phase shifts, and the optical model.
Nuclear Schiff moment
The nuclear Schiff moment is a T,P-violating electric moment of a nucleus, the leading observable one in neutral atoms, and the key nuclear input to atomic EDM searches.
Nuclear Science Laboratory (University of Notre Dame)
The Nuclear Science Laboratory is a low-energy nuclear physics facility at the University of Notre Dame, operating three on-campus particle accelerators since the late 1930s.
Nuclear Security Summit
Nuclear Security Summit (NSS): series of four biennial leaders' summits (Washington 2010, Seoul 2012, The Hague 2014, Washington 2016) launched by Obama to prevent nuclear terrorism by securing and minimizing weapons-usable nuclear material; ended 2016, succeeded by the Nuclear Security Contact Group.