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In logic, negation, also called the logical not or logical complement, is an operation that takes a proposition P {\displaystyle P} to another proposition...

Cargo airlines (or air freight carriers, and derivatives of these names) are airlines mainly dedicated to the transport of cargo by air. Some cargo airlines...

In mathematics and logic, an axiomatic system is any set of primitive notions and axioms to logically derive theorems. A theory is a consistent, relat...

In the mathematical field of dynamical systems, an attractor is a set of states toward which a system tends to evolve, for a wide variety of starting conditions...

Algebraic varieties are the central objects of study in algebraic geometry, a sub-field of mathematics. Classically, an algebraic variety is defined as...

Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam...

Boesenbergia rotunda (Thai: กระชาย krachai, Khmer: ខ្ជាយ k'jeay, Indonesian: temu kunci, Myanmar: ဆိတ္ဖူး "Hsei' Hpu"), commonly known as Chinese keys...

A basidium (pl.: basidia) is a microscopic spore-producing structure found on the hymenophore of reproductive bodies of basidiomycete fungi. These bodies...

Arboriculture (/ˈɑːrbərɪˌkʌltʃər, ɑːrˈbɔːr-/) is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants...

In topology and mathematics in general, the boundary of a subset S of a topological space X is the set of points in the closure of S not belonging to the...

An inquiry (also spelled as enquiry in British English) is any process that has the aim of augmenting knowledge, resolving doubt, or solving a problem...

La Garita Caldera is a large caldera and extinct supervolcano in the San Juan volcanic field in the San Juan Mountains around the town of Creede in southwestern...

Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, and harvestmen....

Electronic filters are a type of signal processing filter in the form of electrical circuits. This article covers those filters consisting of lumped electronic...

Mariner Mark II was NASA's planned family of uncrewed spacecraft for the exploration of the outer Solar System that were to be developed and operated by...

In computer science and telecommunication, Hamming codes are a family of linear error-correcting codes. Hamming codes can detect one-bit and two-bit errors...

William Walden Rubey (December 19, 1898 – April 12, 1974) was an American geologist. He was born in Moberly, Missouri. He attended the University of Missouri...

In category theory, a branch of mathematics, the abstract notion of a limit captures the essential properties of universal constructions such as products...

Christiaan Eijkman (UK: /ˈeɪkmən, ˈaɪkmən/ AYK-mən, EYEK-mən, US: /-mɑːn/ -⁠mahn, Dutch: [ˈkrɪstijaːn ˈɛikmɑn]; 11 August 1858 – 5 November 1930) was a...

The Darrieus wind turbine is a type of vertical axis wind turbine (VAWT) used to generate electricity from wind energy. The turbine consists of a number...