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Direct action

Direct action: confronting objectionable practices or effecting social change by readily available means such as strikes, boycotts, occupations, and civil disobedience, rather than voting; coined in 1920 labor struggles by William Mellor.

Direct Action Day

Direct Action Day, also known as the Great Calcutta Killings, was a Muslim League protest on 16 August 1946 that triggered four days of communal violence in Calcutta.

Direct agglutination test

The direct agglutination test (DAT) is a serological assay that detects anti-Leishmania antibodies in serum by visible clumping of stained parasites, used mainly to diagnose visceral leishmaniasis.

Direct air capture

Direct air capture (DAC) is a chemical process that separates carbon dioxide from ambient air, storing it underground or using it in products like synthetic fuels.

Direct ammonia fuel cell

A direct ammonia fuel cell (DAFC) is a fuel cell that feeds ammonia directly as fuel, converting its chemical energy to electricity without upstream hydrogen production.

Direct analysis in real time mass spectrometry

Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization technique that analyzes samples in open air within seconds, with no sample preparation.

Direct and indirect band gaps

Direct and indirect band gaps distinguish semiconductors whose band edges align in momentum space from those needing phonon help, which is why LEDs use gallium arsenide rather than silicon.

Direct and indirect realism

Direct and indirect realism are rival realist theories of perception: direct realism holds we perceive mind-independent objects themselves, while indirect realism (representative theory) says we perceive only mental sense data representing them. Their arguments, history from Descartes to Reid, and 2026 findings that both are folk conceptions.

Direct Anonymous Attestation

Direct Anonymous Attestation (DAA) is a cryptographic protocol letting a device such as a Trusted Platform Module authenticate remotely without revealing its identity, proposed in 2004.

Direct antiglobulin test

The direct antiglobulin test (DAT) is a blood test detecting antibody or complement proteins bound to red blood cells, used to diagnose immune hemolytic anemia and transfusion reactions.

Direct assessment (pipeline integrity)

Direct assessment (DA) is a pipeline integrity method that combines operating history, indirect survey data, and targeted excavation to examine exposed pipe directly for corrosion defects.

Direct Benefit Transfer

Direct Benefit Transfer (DBT) is India's program for delivering welfare benefits, subsidies, and pensions directly into beneficiaries' bank accounts, launched in 2013 and using Aadhaar as an identifier.

Direct bonding

Direct bonding is a wafer-joining method in which two mirror-polished surfaces, typically silicon or silicon dioxide, adhere spontaneously at room temperature without any adhesive or intermediate material.

Oct 22, 2026

Direct bonding of 2D materials

Direct bonding of 2D materials joins atomically thin crystals like graphene and MoS₂ to wafers or each other without adhesives, enabling integration with silicon circuits.

Oct 22, 2026

Direct C–H arylation via photoredox catalysis

Direct C–H arylation via photoredox catalysis is a family of reactions in which a visible-light photocatalyst generates aryl radicals that install aryl groups onto carbon–hydrogen bonds without prefunctionalization.

Oct 22, 2026

Direct cathode upcycling

Direct cathode upcycling is a battery-recycling approach that repairs and upgrades a spent lithium-ion cathode's chemistry while keeping its crystal structure, converting low-nickel into nickel-rich material.

Direct chill casting

Direct chill casting is a semi-continuous casting process in which molten metal is poured through a bottomless water-cooled mold and withdrawn downward as it solidifies.

Direct collapse black hole seed

A direct collapse black hole seed is a hypothetical massive black hole, 10,000 to a million solar masses, formed when pristine gas in the early Universe collapses directly.

Direct contact membrane distillation

Direct contact membrane distillation (DCMD) is a thermally driven membrane separation process used mainly for desalination, in which warm feed and cold permeate touch the same hydrophobic membrane.

Direct CP violation

Direct CP violation is CP violation arising in the decay amplitudes of a particle rather than in particle-antiparticle mixing, first seen in neutral kaon decays by the NA31 experiment at CERN.

Direct current

Direct current (DC) is the flow of electric charge in a single, constant direction, unlike alternating current; it powers computers, LEDs, solar cells, and electric vehicles.

Direct debit

A direct debit is a pull payment where a business, not the customer, initiates collections from the customer's account under a signed mandate, usually for recurring bills.

Direct deep-sea carbon dioxide injection

Direct deep-sea carbon dioxide injection is a proposed sequestration method that releases captured liquid CO2 into deep ocean, where it would stay isolated from the atmosphere for centuries.

Direct democracy

Direct democracy, or pure democracy, is a form of government in which citizens vote directly on policy through referendums, citizens' initiatives, and recalls instead of acting solely through elected representatives.

Direct Democracy (Polish parliamentary group)

Direct Democracy (Demokracja Bezpośrednia) was a three-member Sejm parliamentary circle of the 9th term, the Kukiz'15 group of Paweł Kukiz, Jarosław Sachajko, and Stanisław Żuk, campaigning for direct democracy.

Direct Democracy Cyprus

Direct Democracy Cyprus (Άμεση Δημοκρατία Κύπρου) is a Cypriot political party founded by MEP Fidias Panayiotou in 2025-2026, letting members vote on policy and candidates via a mobile app; it won 5.4% and four House seats in the May 2026 parliamentary election.