Transcritical cycleA transcritical cycle is a closed thermodynamic cycle where the working fluid goes through both subcritical and supercritical states. In particular, for power cycles the working fluid is kept in the liquid region during the compression phase and in vapour and/or supercritical conditions during the expansion phase. The ultrasupercritical steam Rankine cycle represents a widespread transcritical cycle in the electricity generation field from fossil fuels, where water is used as working fluid.
Arabic alphabetThe Arabic alphabet (الْأَبْجَدِيَّة الْعَرَبِيَّة, ALA ʔælʔæbʒædijːæ-lʕɑrɑbijːæ or الْحُرُوف الْعَرَبِيَّة, ALA), or Arabic abjad, is the Arabic script as it is codified for writing Arabic. It is written from right to left in a cursive style and includes 28 letters. Most letters have contextual letterforms. The Arabic alphabet is considered an abjad, meaning it only uses consonants, but it is now considered an "impure abjad". As with other impure abjads, such as the Hebrew alphabet, scribes later devised means of indicating vowel sounds by separate vowel diacritics.
Numerical stabilityIn the mathematical subfield of numerical analysis, numerical stability is a generally desirable property of numerical algorithms. The precise definition of stability depends on the context. One is numerical linear algebra and the other is algorithms for solving ordinary and partial differential equations by discrete approximation. In numerical linear algebra, the principal concern is instabilities caused by proximity to singularities of various kinds, such as very small or nearly colliding eigenvalues.
Mathematical proofA mathematical proof is a deductive argument for a mathematical statement, showing that the stated assumptions logically guarantee the conclusion. The argument may use other previously established statements, such as theorems; but every proof can, in principle, be constructed using only certain basic or original assumptions known as axioms, along with the accepted rules of inference. Proofs are examples of exhaustive deductive reasoning which establish logical certainty, to be distinguished from empirical arguments or non-exhaustive inductive reasoning which establish "reasonable expectation".
Supercritical carbon dioxideSupercritical carbon dioxide (sCO2) is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure. Carbon dioxide usually behaves as a gas in air at standard temperature and pressure (STP), or as a solid called dry ice when cooled and/or pressurised sufficiently. If the temperature and pressure are both increased from STP to be at or above the critical point for carbon dioxide, it can adopt properties midway between a gas and a liquid.
Canonical coordinatesIn mathematics and classical mechanics, canonical coordinates are sets of coordinates on phase space which can be used to describe a physical system at any given point in time. Canonical coordinates are used in the Hamiltonian formulation of classical mechanics. A closely related concept also appears in quantum mechanics; see the Stone–von Neumann theorem and canonical commutation relations for details.
PausaIn linguistics, pausa (Latin for 'break', from Greek παῦσις, pâusis 'stopping, ceasing') is the hiatus between prosodic declination units. The concept is somewhat broad, as it is primarily used to refer to allophones that occur in certain prosodic environments, and these environments vary between languages. Some sound laws specifically operate only in pausa. For example, certain phonemes may be pronounced differently at the beginning or the end of a word if no other word precedes or follows within the same prosodic unit, such as a word in the citation form.
Atmospheric instabilityAtmospheric instability is a condition where the Earth's atmosphere is considered to be unstable and as a result local weather is highly variable through distance and time. Atmospheric stability is a measure of the atmosphere's tendency to discourage vertical motion, and vertical motion is directly correlated to different types of weather systems and their severity. In unstable conditions, a lifted thing, such as a parcel of air will be warmer than the surrounding air. Because it is warmer, it is less dense and is prone to further ascent.
Lebanese ArabicLebanese Arabic (عَرَبِيّ لُبْنَانِيّ ; autonym: ˈʕaɾabe lɪbˈneːne), or simply Lebanese (لُبْنَانِيّ ; autonym: lɪbˈneːne), is a variety of North Levantine Arabic, indigenous to and spoken primarily in Lebanon, with significant linguistic influences borrowed from other Middle Eastern and European languages and is in some ways unique from other varieties of Arabic. Due to multilingualism and pervasive diglossia among Lebanese people (a majority of the Lebanese people are bilingual or trilingual), it is not uncommon for Lebanese people to code-switch between or mix Lebanese Arabic, French, and English in their daily speech.
AlephAleph (or alef or alif, transliterated ʾ) is the first letter of the Semitic abjads, including Phoenician 𐤀, Hebrew א, Aramaic 𐡀, Syriac ܐ, Arabic ʾ ا, and North Arabian 𐪑. It also appears as South Arabian 𐩱 and Ge'ez አ. These letters are believed to have derived from an Egyptian hieroglyph depicting an ox's head to describe the initial sound of *ʾalp, the West Semitic word for ox (compare Biblical Hebrew ʾelef, "ox"). The Phoenician variant gave rise to the Greek alpha (Α), being re-interpreted to express not the glottal consonant but the accompanying vowel, and hence the Latin A and Cyrillic А.
Jawi scriptJawi (; Jawoë; Kelantan-Pattani: Yawi; d͡ʒä.wi) is a writing system used for writing Malay and several languages of Southeast Asia, such as Acehnese, Banjarese, Kerinci, Maguindanaon, Minangkabau, Tausūg, and Ternate. Jawi is based on the Arabic script, consisting of all of the original 31 Arabic letters, and six additional letters constructed to fit the phonemes native to Malay, and an additional phoneme used in foreign loanwords, but not found in Classical Arabic, which are ca /t͡ʃ/, nga /ŋ/, pa /p/, ga /ɡ/, va /v/, and nya /ɲ/.
