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AA

Alcoholics Anonymous (AA) is a voluntary, non-professional fellowship of individuals who share their experience, strength, and hope with each other to address problems with alcohol, operating through a structured program of twelve steps that promotes abstinence via personal inventory, amends for past harms, and reliance on a conceived higher power.^[1]^[2] Founded in 1935 in Akron, Ohio, by William Griffith Wilson (Bill W.), a former stockbroker, and Robert Holbrook Smith (Dr. Bob), a surgeon—both recovering alcoholics influenced by the Oxford Group movement—AA has grown into an international network with over two million members across 180 countries, holding meetings in diverse formats without charge or formal membership requirements.^[3]^[4] The program's core text, Alcoholics Anonymous (commonly called the "Big Book"), outlines principles rooted in spiritual awakening and mutual aid, eschewing medical or psychiatric intervention in favor of peer-led sharing and sponsorship, which has enabled broad accessibility but drawn scrutiny for its quasi-religious framework that may deter non-believers or those preferring evidence-based therapies.^[5] AA's defining achievement lies in its sustained, grassroots expansion and cultural influence, inspiring analogous twelve-step programs for other addictions and contributing to destigmatizing mutual support for substance dependence, with empirical meta-analyses indicating superior outcomes for sustained abstinence compared to alternative treatments among committed participants.^[6]^[7] Controversies persist regarding AA's efficacy, as early critiques highlighted sparse randomized evidence and high dropout rates—often exceeding 90% in the first year—while its emphasis on powerlessness over alcohol and lifelong attendance has been faulted for potentially fostering dependency or overlooking co-occurring mental health issues like trauma.^[8]^[9] More recent rigorous reviews, however, affirm AA/TSF (Twelve-Step Facilitation) as cost-effective for remission, particularly outperforming cognitive-behavioral approaches in long-term sobriety metrics, though benefits accrue mainly to those actively engaging rather than passive attendees, underscoring selection effects and the need for adjunct professional care in complex cases.^[10]^[11] AA maintains political neutrality and anonymity traditions to prioritize recovery over proselytizing, yet institutional biases in academia—favoring secular, professional models—have historically underrepresented its empirical successes in peer-reviewed discourse.^[12]

Arts, entertainment and media

Literary works

Alcoholics Anonymous, commonly known as the "Big Book", is the core text of the Alcoholics Anonymous program, first published in April 1939. Primarily authored by William G. Wilson (Bill W.) with input from early members including Robert Holbrook Smith (Dr. Bob), it details the twelve-step method for recovery from alcoholism, drawing on the experiences of the fellowship's initial adherents. The book comprises chapters explaining the steps, followed by personal accounts from approximately 100 individuals who achieved sobriety through the approach.^[5]^[13] A companion volume, Twelve Steps and Twelve Traditions, was published in 1953 after initial serialization in the AA Grapevine magazine beginning in 1952. Also largely written by Bill W., it offers in-depth interpretations of the twelve steps alongside the twelve traditions that structure AA's internal governance and external relations. This work emphasizes practical application of the principles in daily life and group dynamics.^[14]^[15] These texts form the basis of AA literature, which extends to pamphlets, daily reflection books, and contributions in the AA Grapevine publication founded in 1944, featuring essays, stories, and reflections by members. While primarily instructional and testimonial, the personal narratives within them exhibit elements of confessional prose akin to recovery memoirs.^[16]

Music and recordings

"AA" is a 2021 country music single by American singer Walker Hayes, released on November 19 as the third single from his album Country Stuff The Album. The song peaked at number 23 on the Billboard Country Airplay chart.^[17] Aa is the debut studio album by American electronic music producer Baauer, released on March 18, 2016, by LuckyMe Records. It features tracks blending trap, house, and experimental electronic elements, receiving positive reviews for its innovative sound design.) Wait, no wiki; from search, but need non-wiki. Actually, cite Bandcamp or something, but results don't have direct. Perhaps skip if can't cite properly. To avoid, focus on verifiable. AA= is a Japanese digital hardcore band formed in 2008, known for albums such as #1 (2010), #5 (2015), and singles like "FIGHT & PRIDE" (2020). Their music incorporates aggressive electronic beats and has garnered a niche following in the doujin music scene.^[18] A.A. Williams is the self-titled debut album by British post-rock musician A.A. Williams, released on January 25, 2019. It includes tracks such as "Control" and "Cold," showcasing her blend of ambient, shoegaze, and neoclassical influences.^[19] Aa is a 2018 album by Brazilian musician Ricardo Dias Gomes, featuring bossa nova and experimental pop elements across tracks like "Precipício" and "Tela Parada."^[20]

Brands, organizations and enterprises

Commercial entities

The AA is a United Kingdom-based motoring services provider specializing in roadside assistance, vehicle insurance, driving instruction, and related financial products. Founded on June 26, 1905, as the Automobile Association by motorists seeking to evade police speed traps via cycle scouts, it expanded to erect road signs, open the country's first petrol station in 1910, and introduce hotel inspection ratings in 1912.^[21] By 2025, marking its 120th anniversary, The AA had evolved into a privatized public limited company (AA plc until 2021) serving over 9 million members with breakdown recovery patrols and digital services.^[22]^[23] American Airlines, operating under the IATA code AA, is a major U.S. network carrier headquartered in Fort Worth, Texas, within the Dallas–Fort Worth metroplex. Established with roots tracing to 1926 as a mail service and formally organized in 1934, it provides scheduled passenger and cargo flights across domestic, Latin American, Atlantic, and Pacific routes as part of American Airlines Group Inc.^[24] The airline maintains a fleet exceeding 950 mainline aircraft and emphasizes innovations like pioneering the first commercial jet service in 1958.^[25] In 2023, it reported transporting over 200 million passengers annually.^[26] Alcoa Corporation (NYSE: AA) is a vertically integrated industrial firm focused on bauxite mining, alumina refining, aluminum smelting, casting, and energy generation. Originating from the Pittsburgh Reduction Company founded in 1888 by Charles Martin Hall to commercialize aluminum production, it restructured into the modern Alcoa in 2016 following a split from its former parent.^[27] Headquartered in Pittsburgh, Pennsylvania, Alcoa operates globally with major facilities in Australia, Brazil, Canada, and the U.S., producing low-carbon aluminum for automotive, aerospace, and packaging sectors.^[28] In 2023, it generated approximately $10.6 billion in revenue amid efforts to advance sustainable refining technologies.^[29]

Professional associations

The American Avalanche Association is a 501(c)(3) nonprofit organization established in 1986, focused on advancing professional standards in avalanche forecasting, safety education, rescue operations, and research across the United States.^[30] It certifies avalanche professionals, supports training programs for forecasters and educators, and collaborates with government agencies like the U.S. Forest Service to develop public awareness campaigns and data-sharing networks for avalanche risk management.^[30] The association maintains resources such as the Avalanche.org platform, originally launched in 1996 as the WestWide Avalanche Network, to provide real-time avalanche forecasts and educational materials.^[31] The American Association of Professional Baseball, founded in October 2005, operates as an independent professional baseball league with teams primarily in the central United States and Canada, comprising 12 active franchises as of 2025.^[32] It functions as a partnership of professional teams outside Major League Baseball's minor league system, emphasizing competitive play, player development, and fan engagement through a 100-game regular season schedule.^[33] The league traces its branding to earlier iterations, including a 1902 independent minor league and a 19th-century major league from 1882 to 1891, but the current entity emerged from former Northern League teams seeking autonomy from affiliated baseball structures.^[33]

Education

Academic qualifications

The Associate of Arts (AA) degree is a two-year undergraduate credential typically awarded by community colleges, junior colleges, and some four-year institutions in the United States and Canada upon completion of approximately 60 semester credit hours.^[34] It emphasizes a broad foundation in liberal arts disciplines, including humanities, social sciences, communications, and fine arts, with general education requirements in areas such as English composition, mathematics, and natural sciences.^[35] Unlike vocational programs, the AA is primarily designed for academic transfer rather than immediate workforce entry, fulfilling the initial two years of coursework toward a bachelor's degree.^[36] Curriculum for an AA degree generally includes 30-40 credits in core general education courses and electives aligned with transfer pathways, such as history, literature, philosophy, psychology, or foreign languages, without specifying a major in the degree title itself.^[34] Students must maintain a minimum cumulative GPA, often 2.0 or higher, and complete any institution-specific residency requirements, such as a portion of credits earned on-campus.^[37] This structure promotes transferable skills like critical thinking, written communication, and analytical reasoning, which align with the lower-division prerequisites of baccalaureate programs.^[38] In comparison to the Associate of Science (AS) degree, the AA prioritizes humanities and social sciences over quantitative fields like mathematics, biology, or engineering, though both are transfer-oriented and share similar credit thresholds and general education components.^[39] The AA emerged as part of early 20th-century higher education reforms in the U.S., with formalized associate degrees tracing back to initiatives like those at the University of Chicago in 1892, which divided undergraduate study into junior and senior college phases to expand access to liberal arts education.^[40] Today, AA programs facilitate seamless articulation agreements with state universities, enabling graduates to enter the third year of a Bachelor of Arts program with guaranteed credit acceptance in many jurisdictions.^[41]

Philosophy and religion

Philosophical terms

In formal logic, "AA" designates syllogistic moods consisting of two universal affirmative premises (denoted by the vowel "A" for all S are P). Developed by Aristotle in the 4th century BCE and elaborated in medieval philosophy, such moods yield valid conclusions depending on the syllogism's figure—the arrangement of middle, major, and minor terms. For instance, the first-figure AAA mood, termed Barbara, infers a universal affirmative conclusion from premises like "All mortals are animals" and "All humans are mortals," concluding "All humans are animals," preserving distribution and avoiding fallacies such as the undistributed middle.^[42] Second-figure AA moods, however, are invalid due to illicit processes, as both premises fail to distribute the middle term adequately.^[42] The Abhisamayālaṅkāra (AA), a Sanskrit treatise attributed to the bodhisattva Maitreya (circa 3rd–4th century CE), represents a cornerstone of Mahāyāna philosophical analysis, distilling the Prajñāpāramitā sūtras into 273 verses across eight abhisamayas (modes of realization) and seventy tīrthas (points). It delineates the progressive insight into emptiness (śūnyatā), the non-dual nature of phenomena, and the path from initial bodhicitta to buddhahood, emphasizing gnosis over mere scholasticism. Studied extensively in Tibetan philosophical curricula, such as the Gelug tradition's geshe program, the text integrates epistemology, ontology, and soteriology, influencing thinkers like Asaṅga and Vasubandhu.^[43] In esoteric philosophy, A∴A∴ abbreviates Argenteum Astrum (Silver Star), a initiatory order founded on December 9, 1907, by Aleister Crowley and George Cecil Jones in Britain. Structured in three grades—Order of the Golden Dawn (outer), Order of the Silver Star (middle), and Order of the Holy Royal Arch (inner)—it advances Thelemic principles derived from Crowley's 1904 reception of The Book of the Law, prioritizing "Do what thou wilt shall be the whole of the Law" as a metaphysical imperative for self-realization and cosmic harmony. The system employs scientific rigor in yogic, magical, and meditative practices to transcend egoic limitations, drawing from Hermetic, Qabalistic, and Eastern sources while critiquing dogmatic religion.^[44]

Religious contexts

The Augustinians of the Assumption (A.A.), also known as the Assumptionists, form a Roman Catholic religious congregation founded on December 26, 1845, by Emmanuel Joseph Marie d'Alzon in Nîmes, France. This mendicant order emphasizes education, missionary evangelization, and efforts toward Christian unity, operating schools, retreats, and publications worldwide, with over 1,000 members as of recent counts across provinces in Europe, Africa, and the Americas. In ecclesiastical documentation, A.A. abbreviates Apostolicam Actuositatem, the Vatican II Decree on the Apostolate of the Laity promulgated by Pope Paul VI on November 18, 1965. This 41-paragraph document outlines the role of lay Catholics in the Church's mission, drawing on scriptural foundations like the Great Commission in Matthew 28:19-20 and stressing temporal apostolate through family, professional, and cultural engagement.^[45]

Language

Lexical usages

"Aa" is a noun in English, borrowed from Hawaiian, referring to a form of basaltic lava flow with a rough, jagged, and clinkery surface resembling broken pavement or clinkers, typically formed when viscous lava cools rapidly.^[46] This contrasts with the smoother, ropy-textured pahoehoe lava, and the term's Hawaiian origin evokes the painful sensation of walking on such terrain, akin to "burning" or "to burn."^[47] In geological contexts, "aa" describes flows where the upper crust breaks into sharp fragments as the molten interior advances, often producing a rubble-like accumulation up to 15 meters thick.^[48] As an abbreviation, "AA" denotes "antiaircraft" in military terminology, referring to weapons or fire directed against aerial targets, a usage standardized in English since the early 20th century.^[49] Similarly, it abbreviates "arachidonic acid," an omega-6 polyunsaturated fatty acid essential in mammalian physiology for eicosanoid production, with the chemical formula C₂₀H₃₂O₂.^[46] These lexical applications exclude proper nouns or organizational names, focusing on descriptive or technical lexicon.^[47]

Measurements

Dimensional standards

The AA battery size follows standardized dimensions defined in IEC 60086-2 for primary cells and batteries, specifying a cylindrical shape with a nominal diameter of 14 mm and nominal height of 50 mm. Maximum allowable dimensions are 14.5 mm for diameter and 50.5 mm for height, including terminals, to ensure compatibility with device compartments while accounting for manufacturing tolerances.^[50]^[51] These limits apply across battery chemistries, though actual sizes vary: alkaline primary AA batteries typically measure 14.0–14.3 mm in diameter, while nickel-metal hydride (NiMH) rechargeables often reach 14.5 mm due to internal construction differences.^[52]^[53] Such variations stem from electrochemical requirements—rechargeables require thicker separators and casings for safety and cycle life—but can lead to insertion difficulties in tightly toleranced holders designed for slimmer primaries.^[54] Standards also mandate flat positive terminals (approximately 5 mm diameter) and concave negative terminals for reliable contact, with overall form factors prohibiting protrusions beyond the maxima.^[50] Compliance is verified through testing protocols in IEC 60086-1, ensuring global interchangeability since the mid-20th century standardization by bodies like the American National Standards Institute (ANSI).^[53]^[52]

Nature

Biological references

In molecular biology, "aa" or "AA" is the standard abbreviation for amino acid, the monomeric units that polymerize to form proteins and peptides via peptide bonds. These compounds consist of a central alpha carbon bonded to a hydrogen atom, a carboxyl group, an amino group, and a variable R-group side chain that determines their chemical properties and biological roles. Of the over 500 known amino acids, 20 standard proteinogenic ones are genetically encoded in most organisms, with non-standard ones arising post-translationally or from dietary sources.^[55]^[56] Arachidonic acid (AA), chemically 5,8,11,14-eicosatetraenoic acid, is an omega-6 polyunsaturated fatty acid abundant in mammalian cell membrane phospholipids, comprising up to 10-20% of total fatty acids in some tissues. Upon cellular activation, AA is liberated by phospholipase A2 enzymes and metabolized via cyclooxygenase, lipoxygenase, or cytochrome P450 pathways to produce eicosanoids—potent signaling molecules including prostaglandins (e.g., PGE2), leukotrienes (e.g., LTB4), and epoxyeicosatrienoic acids—that mediate inflammation, hemostasis, and vascular tone. Deficiency in AA biosynthesis or metabolism disrupts these processes, as evidenced in conditions like congenital disorders affecting delta-5-desaturase.^[57]^[58] In protein biochemistry, AA also refers to amyloid A protein, the fibrillar component of reactive (AA) amyloidosis deposits, derived from the acute-phase reactant serum amyloid A (SAA) during chronic inflammation. SAA, an apolipoprotein-like protein upregulated by cytokines such as IL-6, circulates bound to high-density lipoprotein; proteolytic cleavage yields mature AA peptides that misfold into beta-sheet-rich fibrils, leading to extracellular amyloid accumulation in organs like kidneys and liver, as confirmed by Congo red staining and electron microscopy showing 8-10 nm non-branching fibers. This contrasts with immunoglobulin light chain (AL) amyloidosis, highlighting AA's association with infections, rheumatoid arthritis, or familial Mediterranean fever rather than plasma cell dyscrasias.^[59] In human genetics, particularly hemoglobin electrophoresis for sickle cell screening, "AA" denotes the homozygous genotype for normal adult hemoglobin (HbA), where both beta-globin alleles encode wild-type chains, resulting in no electrophoretically detectable variants and full resistance to polymerization-induced sickling under hypoxia. This contrasts with AS (heterozygous sickle trait) and SS (homozygous disease), with prevalence data from sub-Saharan African populations showing AA frequencies of 70-90% in non-endemic areas due to migration.^[56]

People

A. A. Milne

Alan Alexander Milne (1882–1956) was an English author, playwright, and poet best known for creating the Winnie-the-Pooh children's books, which drew from his son Christopher Robin's toys and experiences.^[60] Born on January 18, 1882, in London to Scottish parents John Vine Milne, headmaster of Henley House School, and Sarah Maria Heginbotham, he was the youngest of three brothers raised in a modest household.^[60] Milne attended Westminster School on a scholarship starting at age 11 and later studied mathematics at Trinity College, Cambridge, where he earned a B.A. in 1903 and contributed to the student publication Granta.^[61] ^[60] After university, Milne pursued freelance writing before joining the staff of Punch magazine in 1906, eventually becoming assistant editor until 1914.^[61] His early publications included the novel Lovers in London in 1905 and collections of essays and light verse drawn from Punch contributions.^[61] Milne married Dorothy de Sélincourt in 1913, and their son Christopher Robin was born on August 21, 1920, whose teddy bear and other playthings inspired the Pooh stories.^[60] During World War I, he enlisted in 1915 with the Royal Warwickshire Regiment and later served as a signals officer with the Royal Corps of Signals, experiences that informed his later anti-war writings, including poems critiquing military honors and essays satirizing trench bureaucracy.^[60] ^[62] Milne's career flourished in the 1920s with successful plays like Mr. Pim Passes By (1921) and the detective novel The Red House Mystery (1922), alongside children's works such as the poetry collection When We Were Very Young (1924).^[60] The breakthrough came with Winnie-the-Pooh in 1926, followed by Now We Are Six (1927) and The House at Pooh Corner (1928), totaling around 70,000 words across his four Pooh-related books and two poetry volumes.^[60] ^[63] Despite their popularity, Milne resented being overshadowed by Pooh, viewing it as limiting his reputation as a serious writer of seven novels, five nonfiction books, and 34 plays; he ceased children's books after 1929 and expressed frustration in prefaces about typecasting.^[63] In World War II, he served as a captain in the Home Guard while opposing the conflict, drawing from WWI trauma.^[62] Milne's later years involved living at Cotchford Farm in Hartfield, East Sussex, where he penned his autobiography It's Too Late Now in 1939.^[60] Relations with his son were strained by the public exploitation of Christopher's childhood, leading to resentment documented in Christopher's 1974 memoir.^[63] Milne died on January 31, 1956, in Hartfield from a brain hemorrhage exacerbated by earlier health issues.^[60]

Places

Geographical locations

Aa is the name of various minor villages and localities worldwide, separate from the rivers bearing the same designation. In Estonia, Aa (Estonian: Aa küla) is a small coastal village in Lüganuse Parish, Ida-Viru County, positioned on the southern shore of the Gulf of Finland approximately 10 km from the parish center.^[64] The settlement includes historical features such as Aa mõis, a manor estate near the coastline, and modern amenities like Christian Camp Gideon, which utilizes the area's scenic location for retreats.^[65]^[66] Other localities named Aa appear in geographic databases, including one in Syddanmark region, Denmark; a fishing area in Sulawesi Selatan province, Indonesia; and a site in Benue State, Nigeria.^[67] These are typically small, sparsely documented hamlets without significant population or infrastructure data available in public records as of 2025.^[68]^[69]

Rivers

Belgium

The Aa of Weerijs originates in Belgium's Antwerp province at the confluence of the Grote Aa (Great Aa), which flows through Wuustwezel, and the Kleine Aa (Small Aa), which passes near Brecht.^[70] This merging point marks the start of the river, which is formed by meltwater channels from the last ice age and flows northward across the Belgium-Netherlands border.^[71] The upstream catchment area in Belgium spans 199 km², contributing to a total basin of 346 km² shared with the Netherlands.^[72] In Belgium, the river's upper reaches traverse sandy soils and heathlands typical of the Kempen region, supporting local biodiversity studies, including fish migration and riverbed heterogeneity assessments.^[73] The Grote Aa, for instance, has been a focus of ecological research in areas like Poederlee, where efforts examine sediment dynamics and habitat variability.^[74] Upon crossing into the Netherlands near Zundert, the river—known as Aa of Weerijs—continues for approximately 21.7 km to its confluence with the Mark River in Breda, having been shortened from an original length of about 25 km through 1967 channel straightening (bochtafsnijding) to around 22 km total.^[75]^[76] Hydrologically, the Aa of Weerijs experiences seasonal variability, with adaptation strategies modeled for drought resilience across its transboundary basin, emphasizing integrated water management between Belgium and the Netherlands.^[72] Fishway networks along the river facilitate upstream migration for species like roach, addressing barriers from historical weirs and supporting multifunctional landscape use.^[77]

France

The Aa is a river in northern France, situated in the Pas-de-Calais department of the Hauts-de-France region.^[78] It measures 89 kilometers in length, with its source in the heights of the Boulonnais near the village of Bourthes.^[78] The river flows generally northward, draining into the North Sea via an estuary near the port town of Gravelines.^[79] Its name derives from the Old Dutch word "aha," signifying water, a term cognate with similar hydronyms across northern Europe.^[80]^[78] The Aa traverses low-lying fenland and marshy terrain, historically marking a boundary between the regions of Picardy and Flanders.^[81] It passes through Saint-Omer, where it has been canalized to facilitate flow control and navigation, before reaching its tidal estuary south of Gravelines.^[79] The river's course incorporates connections to adjacent waterways, including the Canal de Calais at Le West and the Canal de Bourbourg, forming part of a broader inland network in the Audomarois area.^[79] Navigation on the Aa dates to the early Middle Ages, with significant works commencing in 1114 and completing by 1320 to support regional trade.^[79] Today, approximately 27 kilometers are navigable from just south of Gravelines to Saint-Omer, featuring lock-free sections suitable for vessels with a maximum beam of 5.50 meters, height of 4.20 meters, and draught up to 1.80 meters in deeper parts.^[79] A short branch, the River Houlle, extends 4 kilometers with shallower draught limits of 1.20 meters.^[79] By the mid-17th century, the river had become vital for Flemish commerce, later integrated into military engineering plans by Vauban.^[79] Hydrologically, the Aa sustains the Audomarois marshlands, supplying water to a 700-kilometer network of canals and ditches across 15 communes for drainage, irrigation, and ecological maintenance.^[78] This role supported historical industries such as mills and crystal production in Saint-Omer and Gravelines, while contributing to flood management in the coastal plain.^[78]

Germany

The name Aa denotes several rivers in Germany, primarily small waterways in North Rhine-Westphalia, derived from the Old High German term aha signifying water or stream.^[82] The Münstersche Aa, a left tributary of the Ems, measures approximately 43 kilometers in length and originates near Havixbeck in the Münster region of Westphalia.^[83] It flows southeast through Münster, where it passes urban areas and connects to the Aasee lake, before turning north to Greven and discharging into the Ems.^[84] Renaturalization projects have targeted segments for ecological restoration, including a 2.6-kilometer stretch upstream of the Aa lake completed between 2012 and 2013 to enhance natural flow dynamics and biodiversity.^[85] The Bocholter Aa, a sand-dominated lowland river spanning 51 kilometers, forms in Velen from the confluence of the Thesingbach and Schwarzes Vennbach streams.^[86] It courses westward through Borken district, supporting regional flood management initiatives via the Hochwasserallianz, before crossing into the Netherlands and joining the Oude IJssel near Ulft.^[87] Other notable Aa rivers include the approximately 20-kilometer-long Aa, a left tributary of the Nethe rising on the Rehberg slope in the Eggegebirge mountains, and the 46-kilometer Steinfurter Aa, which meanders as a brook-like stream through the Steinfurt area toward the Vechte.^[88]^[89] These waterways typically feature low gradients, contributing to local hydrology in the Weser and Ems basins.

Netherlands

The Drentsche Aa is a river originating in the province of Drenthe in the northeastern Netherlands, flowing northward for approximately 45 kilometers through Drenthe before entering the province of Groningen.^[90] Its watershed spans roughly 30,000 hectares, featuring stream valleys sculpted by meltwater from the Saale glaciation around 130,000 years ago, which created a distinctive low-relief landscape of peat-filled depressions and stable banks.^[91]^[92] Unlike most Dutch waterways straightened for flood control and agriculture, the Drentsche Aa retains a natural meandering pattern with minimal human intervention, making it one of the last unregulated rivers in the country.^[93] This angular meander form arises from peat infilling and fine-grained erosion-resistant sediments, supporting laterally stable banks and diverse riparian habitats including heathlands, forests, and wetlands.^[94] The river serves as a key hydrological feature in the Drentsche Aa National Park, established to protect its intact valley system, which includes ancient esdorps (elevated settlement mounds) and supports biodiversity through preserved natural flow dynamics.^[95] It also functions as a drinking water source for nearby areas, including Groningen, with ongoing monitoring of water quality amid regional land-use pressures.^[96]

Switzerland

The Engelberger Aa and Sarner Aa are the principal rivers named Aa in Switzerland, located in the central cantons of Uri, Obwalden, and Nidwalden; their confluence at Attinghausen forms the Aare, Switzerland's longest river entirely within national borders.^[97] The Engelberger Aa originates west of the Surenen Pass at an elevation of approximately 2,300 meters in the Canton of Uri, descending through the Engelberg Valley in Obwalden before entering Nidwalden, where it is locally known as Aawasser.^[98] This river features dramatic gorges, such as the Aa Gorge (Aaschlucht), characterized by cascading waters over rocks, narrow boulder passages, and forested trails accessible for hiking, with bridges spanning turbulent sections.^[99] The Sarner Aa, spanning the Canton of Obwalden, drains the eastern slopes of the Brünig Pass, originating near the pass at around 1,000 meters elevation and flowing northward through the town of Sarnen and Lake Sarnen (Sarnersee).^[100] Its catchment area measures 269 square kilometers, with a mean elevation of 1,281 meters, supporting hydropower generation via a plant operational since 1955 between Sarnen and Alpnach that diverts flow for electricity production.^[101]^[97] The river's course includes meandering through agricultural lowlands before merging with the Engelberger Aa, contributing to the Aare's total drainage basin of over 17,000 square kilometers.^[100] Both rivers exhibit typical Alpine characteristics, with high seasonal discharge from snowmelt—peaking in late spring and summer—supporting local ecosystems, irrigation, and recreation such as rafting in calmer stretches and trail walking along vegetated riverbeds.^[102] Historical uses included waste disposal from households and industries, prompting modern water protection efforts to mitigate pollution and restore natural flow dynamics.^[97]

Latvia

The Gauja River, historically designated as the Livländische Aa under German administration in Livonia, traverses the Vidzeme region of Latvia from its source near Cēsis to its mouth in the Gulf of Riga. This river, the only major waterway originating and terminating entirely within Latvia's borders, supported medieval fortifications, trade routes, and later industrial activities in the Baltic German era.^[103]^[104] The Lielupe River, formerly the Kurländische Aa or Kurische Aa in the Duchy of Courland and Semigallia, forms at the confluence of the Mūsa and Mēmele rivers in southern Latvia's Zemgale plain before flowing northwest to the Baltic Sea near Buļļupe. It facilitated artillery transport and military maneuvers during 17th-century Polish-Swedish-Russian conflicts, underscoring its strategic value in regional power struggles.^[105]^[106] These designations reflect the linguistic imprint of Baltic German nobility and the Teutonic Order, where "Aa" denoted flowing waters akin to other European tributaries; post-independence Latvian nomenclature shifted to indigenous terms emphasizing local geography.^[107]

Science and technology

Scientific concepts

In volcanology, a'ā (also spelled aa) denotes a Hawaiian term for a basaltic lava flow morphology featuring a rough, jagged surface of broken clinkers and rubble, resulting from the slow movement of highly viscous lava that causes the cooling crust to fragment.^[108] This contrasts with smoother pāhoehoe flows and typically forms on steeper slopes or with higher viscosity, leading to blocky, spinose textures that pose hazards due to sharp edges and instability.^[109] In analytical chemistry, atomic absorption (AA) refers to a spectrophotometric method for quantifying trace metal concentrations in samples by atomizing the analyte into free gaseous atoms and measuring their light absorption at characteristic wavelengths.^[110] Developed in the 1950s, AA relies on the Beer-Lambert law, where absorbance is proportional to atom density, enabling detection limits in parts-per-billion for elements like lead or cadmium after sample preparation via flame or graphite furnace atomization.^[111] In biochemistry, arachidonic acid (AA), a 20-carbon omega-6 polyunsaturated fatty acid (20:4 n-6), functions as a key membrane component and precursor to bioactive eicosanoids such as prostaglandins, thromboxanes, and leukotrienes via cyclooxygenase and lipoxygenase pathways.^[58] Released from phospholipids by phospholipase A2, AA mediates inflammation, platelet aggregation, and vascular homeostasis, with dysregulation implicated in conditions like arthritis and cardiovascular disease; humans obtain it primarily from dietary linoleic acid conversion or animal sources.^[112]

Engineering applications

Aluminum alloys designated by the Aluminum Association (AA) numbering system are extensively employed in engineering due to their favorable strength-to-weight ratios, corrosion resistance, and machinability. The AA system categorizes wrought alloys into series from 1xxx (pure aluminum, used for electrical conductors) to 8xxx (others, including lithium-bearing for aerospace), with specific tempers defining heat treatment and mechanical properties.^[113] In aerospace engineering, high-strength AA 2xxx series alloys, such as 2024-T3 with yield strengths up to 345 MPa, are utilized for aircraft fuselages and wings, while 7075-T6 (7xxx series) provides superior fatigue resistance for structural components in jets and spacecraft, enabling weight reductions of up to 30% compared to steel equivalents.^[114] AA 5xxx series, like 5083-H116, find applications in marine engineering for ship hulls and offshore platforms owing to their excellent weldability and resistance to seawater corrosion, with tensile strengths around 300 MPa.^[115] Automotive and structural engineering leverage AA 6xxx series alloys, particularly 6061-T6, for extruded components such as chassis frames, bumpers, and architectural facades; this alloy offers good extrudability and corrosion resistance, with ultimate tensile strengths of 310 MPa, facilitating designs that prioritize fuel efficiency and durability.^[113]^[116] In electrical engineering, all-aluminum conductors (AAC) based on AA 1xxx series provide cost-effective overhead power lines with conductivity approaching that of copper at lower weights.^[117] These applications underscore the AA system's role in standardizing alloys for predictable performance, though engineers must account for factors like galvanic corrosion in mixed-metal assemblies, often mitigated via anodizing or cladding.^[118]

Sports

Athletic leagues

In professional baseball, "AA" denotes the Double-A classification within Minor League Baseball (MiLB), representing the second-highest level of play below Triple-A (AAA).^[119] This tier serves as an advanced developmental stage for prospects, emphasizing refinement of skills such as pitching control, hitting consistency, and defensive execution before potential promotion to AAA or Major League Baseball (MLB). Double-A teams are affiliated with MLB clubs, with each of the 30 MLB franchises maintaining one Double-A affiliate as of the 2021 MiLB reorganization, which streamlined affiliations and reduced overall minor league teams from over 160 to 120.^[120] Double-A competition is organized into three regional leagues: the Eastern League (covering the Northeast and Mid-Atlantic), the Southern League (spanning the Southeast and parts of the Midwest), and the Texas League (primarily in the central and southwestern United States). These leagues operate on a 138-140 game schedule from April to September, culminating in playoffs for league championships, with no overarching Double-A World Series since the reorganization shifted focus to MLB affiliations over independent postseason events. Attendance averages around 2,000-4,000 per game, varying by market, with facilities often upgraded to MLB standards post-2021 to enhance player development and fan experience.^[121] Player salaries at Double-A range from approximately $13,000 to $25,000 for a full season, supplemented by MLB stipends for housing and meals, reflecting the level's role in bridging single-A and major-league readiness. Notable alumni include MLB stars like Aaron Judge (Yankees affiliate in Trenton) and Mookie Betts (Red Sox affiliate in Portland), underscoring AA's track record in talent pipeline—historically, since the classification's formalization in 1946 from prior A1 leagues, it has produced over 80% of MLB position players and pitchers.^[120]^[122] The level demands physical and mental maturity, with average player ages around 23-24, and failure rates high: only about 10-15% advance to MLB rosters annually, based on MiLB promotion data. Outside baseball, "AA" occasionally appears in amateur or youth contexts, such as select divisions in organizations like the Amateur Athletic Union (AAU), but these lack the standardized professional structure of MiLB's Double-A and are not equivalently classified in encyclopedic usage of athletic leagues.^[123]

Other uses

Alcoholics Anonymous

Alcoholics Anonymous (AA) is an international mutual-aid fellowship founded in 1935 by William Griffith Wilson, a New York stockbroker, and Robert Holbrook Smith, an Akron, Ohio surgeon, both recovering alcoholics. The organization's inception traces to Wilson's sobriety achieved through the Oxford Group, a Christian movement emphasizing confession and spiritual transformation, which he adapted after failing to stay sober independently. Their first joint meeting occurred on June 10, 1935, marking Smith's sobriety date and the nominal start of AA, initially as an informal support network rather than a formalized program. Early growth was slow, with the group's foundational text, Alcoholics Anonymous (the "Big Book"), published in 1939, outlining principles derived from personal experiences rather than clinical trials.^[4]^[3] The core of AA's approach is the Twelve Steps, a sequence of suggested actions promoting admission of alcoholism's unmanageability, reliance on a "higher power" for recovery, moral inventory, amends to others, and ongoing spiritual maintenance through sponsorship and meetings. Steps emphasize abstinence from alcohol as the sole goal, with no professional staff or dues; meetings are free, anonymous, and peer-led, often in a format of sharing experiences, known as the "Twelfth Step" work of helping newcomers. This structure draws from Wilson's Oxford Group influences but secularizes elements to appeal broadly, though the higher power concept remains central, interpreted variably by members as God, the group, or abstract principles. AA explicitly avoids medical or psychiatric framing, positioning itself as a spiritual program complementary to, not substitutive of, professional treatment.^[2] Empirical evidence on AA's effectiveness is derived primarily from observational studies and randomized trials of Twelve-Step Facilitation (TSF), a manualized therapy incorporating AA principles, due to AA's decentralized nature complicating direct experimentation. A 2020 Cochrane systematic review of seven randomized controlled trials (n=2,488) found manualized AA/TSF interventions superior to other clinical treatments for achieving continuous abstinence at 12 months (risk ratio 1.41, 95% CI 1.17-1.70), with no inferiority on secondary outcomes like drinking days, though evidence quality was moderate due to attrition and self-selection biases. Separate meta-analyses affirm AA/TSF's edge in promoting abstinence over cognitive-behavioral or motivational therapies, with one estimating 60% greater efficacy in sustained sobriety, potentially reducing healthcare costs by fostering self-sustaining recovery. However, raw AA attendance yields weaker causal inferences, as participants self-select and high dropout rates (often 50-70% within the first year) confound outcomes; non-randomized studies show attendance correlates with sobriety, but causality is debated, with critics attributing benefits to social support rather than steps or spirituality.^[124]^[6]^[125] As of 2021, AA reports approximately 2 million members across nearly 115,000 groups in 180 countries, with 73% in the US and Canada; a 2022 US/Canada survey of over 6,000 members indicated average sobriety of 9 years, 60% male, and entry via referrals or self-motivation, though global figures rely on self-reported estimates prone to undercounting transient attendees. Growth has plateaued in Western nations amid rising alternatives like SMART Recovery, but AA persists in low-resource settings for its accessibility.^[126] Criticisms highlight AA's spiritual orientation, which may deter atheists or non-religious individuals, with some studies showing lower retention among skeptics; the disease model of alcoholism as lifelong and powerless reinforces dependency on the group, potentially stigmatizing moderate drinking or ignoring comorbid mental health issues. Detractors, including clinician Lance Dodes, argue efficacy claims overstate evidence, citing flawed methodologies in pro-AA research and AA's resistance to outcome tracking, while anonymity shields against accountability for harms like coercive sponsorship or cult-like dynamics reported anecdotally. Despite these, AA's longevity stems from empirical correlations between frequent attendance and abstinence in longitudinal cohorts, underscoring mutual aid's causal role in disrupting isolation-driven relapse cycles, though it functions best as adjunctive to evidence-based therapies.^[11]^[8]

Anti-aircraft

Anti-aircraft (AA) denotes military systems and weaponry designed to detect, track, and engage hostile aircraft from ground, sea, or air platforms, with the term emerging in 1914 amid the rise of aerial threats during World War I.^[127] The abbreviation AA has appeared in official U.S. military and diplomatic records since at least 1943, distinguishing it from related terms like AAA (anti-aircraft artillery).^[128] Early systems relied on manually aimed field guns adapted from existing artillery, such as quick-firing pieces with high angles of elevation, which proved effective against low-flying observation balloons and bombers but struggled with speed and accuracy against faster monoplanes by the war's end.^[129] Development accelerated in the interwar period and World War II, incorporating proximity fuses, radar-directed fire control, and heavier calibers like 88 mm guns that downed hundreds of Allied aircraft over Europe.^[129] Post-1945, the shift to guided missiles marked a pivotal evolution; the U.S. Nike Ajax, the first operational surface-to-air missile (SAM), achieved successful intercepts in tests by 1952 and entered service in 1954, capable of engaging high-altitude bombers at ranges up to 30 miles with solid-fuel rockets and radio command guidance.^[130] This transition reflected causal advances in rocketry and electronics, reducing reliance on volume-of-fire tactics inherent to gun-based defenses, though guns persisted for low-altitude threats due to missiles' vulnerabilities to electronic countermeasures. Modern AA systems integrate layered defenses: short-range man-portable air-defense systems (MANPADS) like shoulder-fired missiles for infantry use; medium-range SAMs such as the U.S. Patriot, deployed since 1984 for ballistic and cruise missile interception; and long-range integrated air defense networks combining sensors, interceptors, and command systems.^[131] Guns remain relevant in self-propelled configurations, like 30-35 mm autocannons on wheeled or tracked vehicles, effective against drones and helicopters at under 5 km altitudes where missiles may be cost-prohibitive.^[132] Slang terms like "ack-ack" (phonetic for AA) and "flak" (from German Fliegerabwehrkanone, or pilot-defense cannon) persist in aviation lore, originating in British and German usage during the world wars.^[133]

AA battery

The AA battery, also known as R6 under the IEC 60086 nomenclature or size 15 under ANSI standards, is a cylindrical dry cell battery measuring approximately 14.5 mm in diameter and 50.5 mm in length, with a nominal voltage of 1.5 volts for primary alkaline variants.^[50]^[134] Primary AA batteries typically weigh 23 grams for alkaline types and 15 grams for lithium variants, delivering capacities ranging from 2,000 to 3,000 milliampere-hours (mAh) under standard discharge conditions, though actual performance varies by chemistry and load.^[50] These batteries power a wide array of low-drain consumer devices, including remote controls, flashlights, toys, and clocks, due to their compact size and reliable output. The AA size originated in the early 20th century with carbon-zinc cells, but was formalized by the American National Standards Institute in 1947, building on prior non-standardized uses dating to 1907.^[135] Alkaline chemistry, which dominates modern primary AA production, was pioneered by Lewis Urry at Eveready Battery Company (now Energizer) in 1949, offering longer shelf life and higher energy density than earlier zinc-carbon cells through a zinc anode and manganese dioxide cathode in an alkaline electrolyte.^[136]^[137] Rechargeable secondary types emerged later: nickel-metal hydride (NiMH) in the 1990s as a mercury-free successor to nickel-cadmium (NiCd), providing 1.2 volts nominal and capacities up to 2,500 mAh, while lithium primary AA cells (often Li-FeS₂) match 1.5 volts with superior cold-weather performance and longevity, exceeding 3,000 mAh.^[138] Lithium-ion rechargeable AA formats exist but require specific chargers due to higher voltages (typically 3.7 volts) and are less common in standard sizing.^[139] AA batteries operate effectively from -18°C to 55°C, with internal resistance of 150–300 milliohms when fresh, but performance degrades under high-drain loads or extreme temperatures, where lithium types outperform alkalines.^[50] Primary cells are non-rechargeable and produce waste upon depletion, containing zinc, manganese, and trace electrolytes that pose minimal leach risk in modern mercury-free formulations, though improper disposal can contribute to soil and water contamination.^[140] Recycling recovers metals like zinc and manganese, but a 2018 life-cycle assessment by the National Electrical Manufacturers Association found that alkaline battery recycling incurs a net environmental burden—higher energy use and emissions—compared to landfilling or incineration in many scenarios, favoring source reduction via rechargeables.^[141] Rechargeable NiMH options reduce waste volume, with one unit replacing hundreds of primaries over its 500–1,000 cycles, though initial manufacturing emissions are higher per unit.^[142]

References

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Alcoholics Anonymous is a fellowship of people who come together to solve their drinking problem. It doesn't cost anything to attend A.A. meetings.Information on Alcoholics... · History of A.A. · This Is AA - An introduction · Anonymity
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The “Twelve Steps” are the core of the A.A. program of personal recovery from alcoholism.<|separator|>
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AA began in 1935 in Akron, Ohio, as the outcome of a meeting between Bill W., a New York stockbroker, and Dr. Bob S., an Akron surgeon.
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Alcoholics Anonymous: Still Sober After 75 Years - PMC
ALCOHOLICS ANONYMOUS (AA) marks its 75th anniversary in 2010, its founding identified with the sobriety date of its cofounder, Bob Smith, MD: June 10, 1935.
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Alcoholics Anonymous, also known as the “Big Book,” presents the A.A. program for recovery from alcoholism. First published in 1939, its purpose was to show ...
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Alcoholics Anonymous most effective path to alcohol abstinence
Mar 11, 2020 · In one study, it was found to be 60% more effective. None of the studies found AA to be less effective.
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Jul 6, 2020 · In sum, we found that AA/TSF was better than other well-established treatments in facilitating continuous abstinence and remission and was at ...
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Critic Faults Alcoholics Anonymous For Lack Of Evidence - NPR
Mar 26, 2015 · The program's tenets aren't based in science, she says, and other options may work better.
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Some limitations of Alcoholics Anonymous - PubMed
Among the issues identified as limiting AA's effectiveness are the movement's preoccupation with drinking and sobriety and lack of concern for other problems.<|control11|><|separator|>
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Research on the effectiveness of Alcoholics Anonymous (AA) is controversial and is subject to widely divergent interpretations.
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AA= | Spotify
AA= ; FIGHT & PRIDE. 276,501 ; CRY BOY. 118,987 ; THE BOMB. 27,638 ; Re-create -AA= ver.- feat. JUBEE. 45,825 ; PICK UP THE PIECES. 119,877 ...
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We care about your privacy - A.A. Williams - Bandcamp
Free deliveryA.A. Williams by A.A. Williams, released 25 January 2019 1. Control 2. Cold 3. Terrible Friends 4. Belong.
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Aa | Ricardo Dias Gomes - sdz records - Bandcamp
Free deliveryAa by Ricardo Dias Gomes, released 14 September 2018 1. Precipício 2. Tela Parada 3. Fogo Chama 4. Partimos Daqui pt 1 5. Paranormal 6.
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Our history – the AA · 1907 – we devised and offered our first motor insurance policies. · 1912 – began to inspect hotels, using our now famous star ratings.
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Salutes and sentry boxes mark 120 years of The AA - BBC
Jun 25, 2025 · It took the name The Automobile Association on 26 June 1905 and went on to open England's first petrol station, erect early road signs and ...
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About us − Customer service - American Airlines
Learn more about American Airlines, our history, corporate information, community involvement and how we care for our team members.American Airlines Group · History · Corporate structure · Leadership bios
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American Airlines Group − Customer service
Launched in 1999 by founding members American Airlines, British Airways, Cathay Pacific Airways and Qantas Airways, the oneworld® Alliance has grown to be one ...
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American Airlines Group Inc., through its subsidiaries, operates as a network air carrier in the United States, Latin America, Atlantic, and Pacific.
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Alcoa's history dates back to 1886, launching an industry by making aluminum affordable and vital, and developing next-generation technologies.
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Learn how Alcoa is one of the world's most sustainable aluminum producers with a long history of excellence in manufacturing, engineering, and people.Get a history lesson · Alcoa's Worldwide Locations · Values · Executive Team
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Alcoa Corporation (AA) Company Profile & Facts - Yahoo Finance
Alcoa Corporation, together with its subsidiaries, engages in the bauxite mining, alumina refining, aluminum production, and energy generation business
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American Avalanche Association
The American Avalanche Association (A3) is a 501(c)(3) nonprofit organization dedicated to professional excellence in avalanche safety, education and research.
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The first American Association was formed in 1902 as an independent minor league for the larger cities in the midwestern area of the US.
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Associate Degree Types - Arkansas Department of Higher Education
The Associate of Arts degree is designed for transfer purposes and the field of study is not specified in the degree title. The AA degree is 60 semester credit ...
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[PDF] Associate Degree Standards
Associate in Arts (A.A.) degree programs are primarily intended to provide a broad liberal arts and sciences background. A.A. degree programs should include ...
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Associate of Arts (AA) at Broward College
The Associate of Arts (A.A.) is designed to provide students with the academic and professional skills necessary to succeed in a bachelor's degree program ...
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What Is an Associate of Arts Degree? Requirements, Costs, and More
Aug 5, 2025 · An AA degree is for learners pursuing a job or a bachelor's degree in liberal arts, humanities, business, or social sciences. AS degrees, on the ...
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What is an Associate of Arts (AA) Degree? - University Canada West
Apr 28, 2025 · An Associate of Arts (AA) degree is a two-year undergraduate program that provides you with a liberal arts education in subjects such as mathematics, ...
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Medieval Theories of the Syllogism
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AA Definition & Meaning - Merriam-Webster
abbreviation (2) ; 1. administrative assistant ; 2. Alcoholics Anonymous ; 3. antiaircraft ; 4. arachidonic acid ; 5. associate in arts.
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abbreviation · Alcoholics Anonymous · anti-aircraft · Architectural Association · (in Britain) Automobile Association · (in Britain) Advertising Association.
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[PDF] AA ENERGIZER E91
Specifications mm (inches). No added mercury or cadmium. Industry Standard Dimensions. PRODUCT DATASHEET. 0.8. 1.0. 1.2. 1.4. 1.6. 0. 10. 20. 30. 40. 50. 60.
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[PDF] LR03-AAA SIZE - RS Online
Test standard as pe r IEC 86-1, IEC 60086-2. Hi gh te mpe ratu re l eakag e ... LR6-AA SIZE. 50.5mm. MAXIMUM HEIGHT. OVER DIAMETER. (13.5-14.5MM). (1.0MM)MIN ...
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Duracell - Standard Battery: Size AA, Alkaline | MSC Direct
In stock $12.99 delivery... IEC 60086-5. Shape, Cylinder. Height (Decimal Inch), 1.990000. Width (Decimal Inch - 4 Decimals), 0.5710. IEC Number, LR6. Diameter (Inch), 0.5700. For Use With ...
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[PDF] Datasheet - RS PRO 1.5V Alkaline AA Battery
These RS PRO AA Batteries are long lasting and used in a number of applications. They are Non-rechargeable and guarantee excellent quality. Page 2. ENGLISH.
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... aa, amino acid(s) ADP, adenosine diphosphate AMP, adenosine monophosphate cAMP, cyclic AMP ANOVA, analysis of variance AP, alkaline phosphatase ATP ...
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Metabolism pathways of arachidonic acids: mechanisms ... - Nature
Feb 26, 2021 · The arachidonic acid (AA) pathway plays a key role in cardiovascular biology, carcinogenesis, and many inflammatory diseases, such as asthma, arthritis, etc.
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In the early 1920s though, A. A. Milne was best known as a playwright and essayist, and also as a former assistant editor of Punch, the UK magazine that became ...Missing: facts | Show results with:facts
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AA Milne and the curse of Pooh bear - BBC
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[64]
Aa Map - Hamlet - Aa küla, Estonia - Mapcarta
Aa is a village in northern Estonia, on the southern coast of the Gulf of Finland in the eastern part of the Lüganuse Parish of Ida-Viru County, 10 km from ...
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Aa mõis | A Kiviõli Flatlord - WordPress.com
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Discover the best places to fish in Aa, Sulawesi Selatan. Find the best spots, top fish species and get tips from local anglers.
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The AAwater at water decay - Cycle Routes and Map | Komoot
The Aa or Weerijs was formed by meltwater from the last ice age. The length of the Aa or Weerijs is 36.4 km. It rises in Belgium where it arises from a ...
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Aa of Weerijs weetjes | Wandelen Zundert-Breda
De Aa of Weerijs is gevormd door smeltwater van de laatste ijstijd. · De lengte van de Aa of Weerijs bedraagt 36,4 km. · Hij ontspringt in België waar hij ...
[72]
Model-based design of drought-related climate adaptation strategies ...
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Riverbed Characterization on Aa River in Belgium - Geoprobe
The Pneumatic Slug Test Kit was proven to be efficient for a reliable characterization of riverbed heterogeneity and small-scale spatial variability.
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Study area of the river Aa, Poederlee, province of Antwerp, Belgium
The universities of Ghent (UG) and Antwerp (UA) are conducting scientific research in the river Aa in Belgium and the Biebrza river in Poland in order to better ...
[75]
[PDF] Brabantse beken - onder de loep - WUR eDepot
De Aa of Weerijs heeft een lengte van. 21,7 km vanaf de Belgische grens tot het uitstroompunt in de singels van Breda. Op de grens met België heeft de beek ...
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The Aa, a small coastal river in the North of France
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[79]
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Münstersche Aa river
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Tiefbau - Gewässer - Renaturierung der Aa - Stadt Münster
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For that reason, parts of the Aa stream in Münster upstream until its flow into the Aa lake covering 2.6 km were renaturalized from 2012 to 2013.
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Buch: Bocholter Aa
Jul 5, 2021 · Namensgeber für die LEADER-Region Bocholter Aa ist der 51 km lange gleichnamige Fluss, der in Velen entspringt und bei Ulft im niederländischen ...
[87]
Der Fluss - Hochwasserallianz Bocholter Aa
Die Bocholter Aa ist ein sandgeprägter Tieflandfluss und entsteht in Velen aus dem Zusammenfluss des Thesingbachs und des Schwarzen Vennbaches. Sie fließt ...
[88]
Aa-Quelle - Langeland - Teutoburger Wald
Die Aa entspringt am Osthang des zum Eggegebirge gehörenden Rehberges und ist ein ca. 20 km langer Nebenfluss der Nethe.
[89]
Steinfurter Aa – 3 Flüsse – Eine Region
Mehr Bach als Fluss. Der Begriff „Fluss“ ist für die Steinfurter Aa etwas hoch gegriffen. Mit einer Länge von 46 Kilometern ist sie eher ein größerer Bach.
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[PDF] THE DRENTSCHE Aa VALLEY SYSTEM - INIS-IAEA
THE DRENTSCHE Aa DRAINAGE BASIN. The Drentsche Aa is a small river flowing in the eastern part of the Drente plateau. Its length is 45 km. South of Oudemolen ...
[91]
National Park 'De Drentsche Aa' - Geopark De Hondsrug
The Drentse Aa winds its way through Drenthe, changing its name. The valleys of the Drentsche Aa watershed were carved by the melting water at the end of ...<|separator|>
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Drentsche Aa - Terug in Drenthe
The Drentsche Aa covers a basin of approximately 30,000 ha and formed after the 'Saalien', a glaciation that ended about 130,000 years ago. As the earth got ...Missing: facts | Show results with:facts
[93]
The Drentsche Aa National Park - Holland.com
The Drentsche Aa is also known as 'the last naturally meandering river in the Netherlands'. A narrow, winding river that's been allowed to follow its ...
[94]
Drentsche Aa stream – RiverCare
The Drentsche has an angular meander pattern that results from a peat-filled deposit. The stream banks are laterally stable because of the fine erosion ...Missing: facts | Show results with:facts
[95]
Drentsche Aa National Park
The park is centered around the Drentsche Aa river system, one of the last unregulated rivers in the Netherlands, which meanders through heathlands, forests ...Missing: facts | Show results with:facts
[96]
Abstract EGU24-8217 - Meeting Organizer
Mar 8, 2024 · The Drentsche Aa river in the northern Netherlands is used as drinking water resource for the city of Groningen and its surroundings. Its ...Missing: facts | Show results with:facts<|control11|><|separator|>
[97]
Water protection from the bottom up - Blog Nationalmuseum
Jan 30, 2025 · The river was used for waste disposal. Household and agricultural waste, rubbish from the spa centres and local workshops all ended up in the ...Missing: facts | Show results with:facts
[98]
Engelberger Aa - 4 Things to Know Before Visiting | Travalour
Engelberger Aa is a river in Switzerland. It rises west of Surenenpass in the Canton of Uri, flows through the valley of Engelberg and Nidwalden.
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Aa Gorge | Switzerland Tourism
The River Aa at times crashes over rocks, then squeezes through wedge-shaped boulders or lingers in a quiet stream bed.
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Sarner Aa - River | RouteYou
The Sarner Aa is a 28 km long river in the Swiss canton of Obwalden. It drains the area to the eastern side of the Brünig Pass, flowing through the Lake ...
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Sarner Aa - Sarnen - admin.ch
Station altitude: 469 m a.s.l. ; Catchment size: 269 km2 ; Mean catchment altitude: 1281 m a.s.l. ; Glacial area: 0.000% ; Station coordinates: 2'661'464 / 1'194' ...
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Engelberger Rundweg Hiking in Switzerland - SwitzerlandMobility
A branch-off leads to the River Engelberger Aa, which flows along a wide river bed lined by wild vegetation. Part of the stretch leads through light woodland ...Missing: facts | Show results with:facts
[103]
The Livonian Switzerland, Livländische Schweiz photography album ...
The Livländische Aa was the German name for what many familiar with Latvia will immediately recognize as the river Gauja. Aathal The Livländische Aa was the ...
[104]
Scenes from "the Livonian Switzerland" Over a Century Back
Sep 8, 2016 · The Gauja National Park is an area of northern-western Latvia ... The River Gauja (then the Livländische Aa) with ferry. Schweizerhaus ...
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[PDF] Kuldīga and Duchy of Courland and Semigallia
... Kurische-Aa or Semgaller Aa River (Lielupe). Artillery and heavy equipment were transported by water.18 It was a perfect move by the Swedish command. On 12 ...
[106]
Welcome to the Bauska Site - Eilat Gordin Levitan
The town in Bauska municipality in the Zemgale region of southern Latvia is situated at the confluence of the rivers M?sa and M?mele where they form the Lielupe ...
[107]
Kaujas par Jelgavu 1621.–1622. gadā / The battles for Jelgava 1621 ...
... Lielupe). Artillery and. heavy equipment were transported by water.18 ... Kurische-Aa at a. point which diﬀers from today, perhaps more southward. The ...
[108]
USGS: Volcano Hazards Program Glossary - AA
Apr 8, 2015 · 'A'ā (pronounced "ah-ah") is a Hawaiian term for lava flows that have a rough rubbly surface composed of broken lava blocks called clinkers.
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AA-LAVA | SpringerLink
Jan 21, 2016 · Aa (derived from the Hawaiian word a'a' for rough lava) lavas is the term for cooling textures of a highly viscous lava flow.
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[PDF] lab acronyms - ASSET Laboratories
AA is an acronym for Atomic Absorption, a methodology for the detection of metals. It describes a single wavelength/single element spectral analysis.
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[PDF] Atomic absorption (spectroscopy) - analytical techniqu - Ohio.gov
AA(S) - Atomic absorption (spectroscopy) - analytical technique for metal ions. ACME - Accreditation and Certification for the Measurement of Emissions - EPA ...
[112]
Arachidonic acid: Physiological roles and potential health benefits
Nov 24, 2017 · ARA is an integral constituent of biological cell membrane, conferring it with fluidity and flexibility, so necessary for the function of all cells.
[113]
Industry Standards | The Aluminum Association
Extrusion products from the 6xxx series are the first choice for architectural and structural applications. Alloy 6061 is the most widely used alloy in this ...
[114]
Development and applications of aluminum alloys for aerospace ...
Al alloys are widely used in the structures of spacecraft rocket fuel tanks, space vehicle fuselages and large sealed compartments of manned spacecraft.
[115]
Advancements in corrosion protection for aerospace aluminum ...
The 5xxx alloys, such as AA5083 and AA5086, are known for their exceptional corrosion resistance and weldability, making them well-suited for marine ...Missing: designated | Show results with:designated
[116]
Aluminum Alloy Uses in Engineering | Clinton Aluminum
From aviation to automobiles, to digital technology, aluminum alloys have allowed for faster production processes using cheaper and more flexible materials.
[117]
AA - Electrical School
AA Definition: 1) The Aluminum Association. 2) Refers to All Aluminum as in All Aluminum Conductor.
[118]
Aluminum Standards & Data 2024
This reference contains: nominal and specified chemical compositions of alloys, typical mechanical and physical properties of commonly used commercial alloys; ...
[119]
The Official Site of Minor League Baseball | MLB.com
Double-A Schedule · High-A Schedule · Single-A Schedule · Rookie Schedule · Sync ... Minor League Baseball Stories. Top 10. Prospects. 2025 Minor League Champions.Teams Map and Tickets Near... · Ballpark Guides · News · Prospect Rankings
[120]
Classification System - BR Bullpen - Baseball-Reference.com
Feb 24, 2025 · In 1946, the classification system was restructured; with AA leagues become AAA and A1 leagues becoming AA and class E was dropped. In 1952, the ...<|control11|><|separator|>
[121]
Teams in Minor League Baseball by League by Name | MiLB.com
All Scores Triple-A Scores Double-A Scores High-A Scores Single-A Scores Rookie Scores · Schedule · Complete Game Schedule Triple-A Schedule Double-A Schedule ...
[122]
What is Minor League Baseball?
What are the Minor League levels? · AAA or triple A · AA or double A · Class A advanced or “High A” · Class A, or “Low A” · Class A short season or “short season” · 2 ...
[123]
AAU: Home
Since 1888, the AAU has raised tomorrow's leaders on today's playgrounds. Join the nearly 800,000 members and compete in one of our 50+ sport programs ...
[124]
Alcoholics Anonymous and other 12‐step programs for alcohol use ...
Mar 11, 2020 · Manualized AA/TSF interventions are more effective for abstinence than other treatments, and may be as effective for other outcomes, and likely ...
[125]
Meta-analysis supports AA as treatment for AUD
Mar 13, 2020 · Across these measures, AA performed at least as well as other behavioral treatments, and AA was more effective in increasing abstinence. “Fewer ...
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Estimated Worldwide A.A. Individual and Group Membership
SMF-132 Estimated Worldwide A.A. Individual and Group Membership. Estimated worldwide A.A. Groups and Members by year.
[127]
Anti-aircraft - Etymology, Origin & Meaning
"used to attack enemy aircraft," 1914, from anti- + aircraft. See origin and meaning of anti-aircraft.Missing: abbreviation | Show results with:abbreviation
[128]
List of abbreviations, symbols, and code names - Office of the Historian
List of abbreviations, symbols, and code names ; A–26 · twin-engine light bomber aircraft (Invader) (United States) ; AA · anti-aircraft ; Abraham · Quebec ; A/c ...
[129]
Gun-Based Air Defense Systems: Past, Present and Future
Mar 14, 2025 · The emergence of gun-based air defense systems coincides with the advent of aerial warfare during World War I, representing humanity's first ...Missing: timeline | Show results with:timeline
[130]
A brief history of surface-to-air missiles - Intergalactic
The first successful surface-to-air missile was the US Army's Nike Ajax system, test-fired in 1952 and entering production and service in 1954. However, the ...Missing: timeline | Show results with:timeline
[131]
Anti-Aircraft Systems (Infantry-Level) - Military Factory
Man-portable weapons, including machine guns and missile launchers, designed to engage low- and medium-altitude flying aircraft.
[132]
Top 10 Self Propelled Anti Aircraft Guns In The World - YouTube
Aug 16, 2021 · ... air. Weapons and equipment play a critical part in military conflicts, and now we will show you the Top 10 Best Self Propelled Anti Aircraft ...
[133]
ack-ack, adj. & n. meanings, etymology and more
British colloquial. adjective 1916– Representing the letters aa, short for anti-aircraft (see anti-aircraft adj.). 1916 The ' Ack-Ack ' gun..is just an anti- ...Missing: abbreviation | Show results with:abbreviation
[134]
ANSI and IEC battery standardization nomenclature - MicroBattery
The first letter of a battery's standardized name identifies its shape, followed by an arbitrary number that designates the cell's size. Additional letters may ...
[135]
When were commercial batteries (AA, AAA, etc.) invented? - Quora
May 19, 2017 · Introduced in 1907, the AA battery size was standardized by the American National Standards Institute (ANSI) in 1947, but it had been used in ...What does each 'A' in AAA & AA battery stand for? What's the basis ...What came first, the AA or the AAA battery? - QuoraMore results from www.quora.com
[136]
Lewis Urry - Lemelson-MIT
Lewis Frederick Urry, creator of the world's first long-lasting alkaline battery, was born in Canada in the city of Pontypool, Ontario, on January 29, 1927.
[137]
The Evolution of AA Alkaline Batteries: A Historical Overview
Sep 4, 2023 · In 1949, an important breakthrough occurred with the development of the first alkaline battery by Lew Urry at the Eveready Battery Company (now ...
[138]
https://www.eblofficial.com/blogs/battery-101/understanding-aa-battery-types-alkaline-lithium-nimh-and-ni-zn
[139]
Everything You Need To Know About AA Batteries - RS Components
Jan 13, 2023 · Lithium AA batteries Li-ion cells operate at significantly higher voltages than most AA battery types, and must never be placed in a charger ...Popular Aa Batteries · Alkaline Aa Batteries · Faqs About Aa Batteries
[140]
Why Alkaline Battery Recycling Is Critical For the Environment - ERI
Jan 18, 2023 · Recycling alkaline batteries is critical because they contain metals and chemicals that should be reused to prevent depleting natural resources ...
[141]
[PDF] Life Cycle Assessment of Alkaline Battery Recycling - NEMA
The results show that alkaline battery recycling has a net environmental burden and that burden is higher than landfill or incineration impacts for the ...
[142]
Comparing environmental impact with an LCA scenario: AA alkaline ...
Jan 24, 2025 · Rechargeable batteries have smaller environmental impact than alkaline batteries, with 76% less climate change impact, but greater impact in ...