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Litmus Paper
Litmus is a water-soluble mixture of different dyes extracted from lichens. It is often absorbed onto filter paper to produce one of the oldest forms of pH indicator, used to test materials for acidity. It is a purple dye that is extracted from a type of algal bloom called ‘lichens’. In an acidic medium, blue litmus paper turns red, and red litmus paper turns blue in a basic or alkaline medium. History The word "litmus" comes from an Old Norse word for "pulp". About 1300 the Spanish physician Arnaldus de Villa Nova began using litmus to study acids and bases. From the 16th century onwards, the blue dye was extracted from some lichens, especially in the Netherlands. Natural sources Litmus can be found in different species of lichens. The dyes are extracted from such species as ''Roccella tinctoria'' (South American), ''Roccella fuciformis'' (Angola and Madagascar), ''Roccella pygmaea'' (Algeria), ''Roccella phycopsis'', '' Lecanora tartarea'' (Norway, Sweden) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roccella Fuciformis
''Roccella'' is a genus of 23 species of lichens in the family Roccellaceae. The genus was circumscribed by Swiss botanist Augustin Pyramus de Candolle in 1805, with '' Roccella fuciformis'' as the type species. Species *'' Roccella albida'' *'' Roccella bajasurensis'' *'' Roccella botrytis'' *'' Roccella colonii'' *'' Roccella elisabethae'' *'' Roccella floreana'' *''Roccella floribrassica'' *'' Roccella fuciformis'' *'' Roccella fusca'' *'' Roccella geniculata'' – Galápagos Islands *''Roccella glebaria'' – Galápagos Islands *''Roccella gracilis'' *''Roccella hertelii'' *''Roccella incurvata'' *''Roccella kappeniana'' – Galápagos Islands *''Roccella maderensis'' *''Roccella minuta'' *''Roccella montagnei'' *''Roccella phycopsioides'' *''Roccella phycopsis ''Roccella phycopsis'' is a species of lichen in the family Roccellaceae. A study of ''Roccella phycopsis'' in Tunisia revealed that it contains methyl orcellinate, a chemical compound of inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form Hydroxide ions OH−. These ions can react with hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Ca(OH)2. Such aqueous hydroxide solutions were also described by certain characteristic properties. They are slippery to the touch, can taste bitter and change the color of pH indicators (e.g., turn red litmus paper blue). In water, by altering the autoionization equilibrium, bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a ''transaction''. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, Andreas Reuter and Theo Härder coined the acronym ''ACID'', building on earlier work by Jim Gray who named atomicity, consistency, and durability, but not isolation, when characterizing the transaction concept. These four properties are the major guarantees of the transaction paradigm, which has influenced many aspects of development in database systems. According to Gray and Reuter, the IBM Inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base (chemistry)
In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form Hydroxide ions OH−. These ions can react with hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Ca(OH)2. Such aqueous hydroxide solutions were also described by certain characteristic properties. They are slippery to the touch, can taste bitter and change the color of pH indicators (e.g., turn red litmus paper blue). In water, by altering the autoionization equilibrium, bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid (chemistry)
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a ''transaction''. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, Andreas Reuter and Theo Härder coined the acronym ''ACID'', building on earlier work by Jim Gray who named atomicity, consistency, and durability, but not isolation, when characterizing the transaction concept. These four properties are the major guarantees of the transaction paradigm, which has influenced many aspects of development in database systems. According to Gray and Reuter, the IBM Inform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litmus Paper
Litmus is a water-soluble mixture of different dyes extracted from lichens. It is often absorbed onto filter paper to produce one of the oldest forms of pH indicator, used to test materials for acidity. It is a purple dye that is extracted from a type of algal bloom called ‘lichens’. In an acidic medium, blue litmus paper turns red, and red litmus paper turns blue in a basic or alkaline medium. History The word "litmus" comes from an Old Norse word for "pulp". About 1300 the Spanish physician Arnaldus de Villa Nova began using litmus to study acids and bases. From the 16th century onwards, the blue dye was extracted from some lichens, especially in the Netherlands. Natural sources Litmus can be found in different species of lichens. The dyes are extracted from such species as ''Roccella tinctoria'' (South American), ''Roccella fuciformis'' (Angola and Madagascar), ''Roccella pygmaea'' (Algeria), ''Roccella phycopsis'', '' Lecanora tartarea'' (Norway, Sweden) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrographa Leucophoea
''Dendrographa'' is a genus of lichen-forming fungi in the family Roccellaceae The Roccellaceae are a family of fungi in the order Arthoniomycetes. Most taxa are lichenized with green algae, although some are lichenicolous, growing on other lichens. Genera , Species Fungorum (in the Catalogue of Life) accepts 47 genera .... It has seven species. It was given its current name by Otto Vernon Darbishire in 1895. Species *'' Dendrographa alectoroides'' *'' Dendrographa austrosorediata'' – Brazil *'' Dendrographa conformis'' *'' Dendrographa decolorans'' *'' Dendrographa franciscana'' *'' Dendrographa latebrarum'' *'' Dendrographa leucophaea'' References Roccellaceae Arthoniomycetes genera Lichen genera Taxa named by Otto Vernon Darbishire Taxa described in 1895 {{Arthoniomycetes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roccella Montagnei
''Roccella'' is a genus of 23 species of lichens in the family Roccellaceae. The genus was circumscribed by Swiss botanist Augustin Pyramus de Candolle in 1805, with ''Roccella fuciformis'' as the type species. Species *'' Roccella albida'' *'' Roccella bajasurensis'' *'' Roccella botrytis'' *'' Roccella colonii'' *'' Roccella elisabethae'' *'' Roccella floreana'' *''Roccella floribrassica'' *''Roccella fuciformis'' *'' Roccella fusca'' *'' Roccella geniculata'' – Galápagos Islands *''Roccella glebaria'' – Galápagos Islands *''Roccella gracilis'' *''Roccella hertelii'' *''Roccella incurvata'' *''Roccella kappeniana'' – Galápagos Islands *''Roccella maderensis'' *''Roccella minuta'' *'' Roccella montagnei'' *''Roccella phycopsioides'' *''Roccella phycopsis'' *'' Roccella sanctae-helenae'' *'' Roccella stipitata'' – Galápagos Islands *''Roccella tinctoria ''Roccella tinctoria'' is a lichenised species of fungus in the genus ''Roccella'', homo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmelia (lichen)
''Parmelia'' is a genus of medium to large foliose lichens.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, It has a global distribution, extending from the ArcticSkult H (1985) A New Subspecies of ''Parmelia omphalodes'' Ascomycetes Described from the Arctic. Annales Botanici Fennici 22, 201-6. to the Antarctic continentD.C. Lindsay (1973) Notes on Antarctic lichens: IV. The genera ''Cetraria'' Hoffm., ''Hypogymnia'' (Nyl.) Nyl., ''Menegazzia'' Massal, ''Parmelia'' Ach. and ''Platismatia'' Culb. et Culb. British Antarctic Survey Bulletin 36, 105-114. but concentrated in temperate regions. There are about 40 species in ''Parmelia''. In recent decades, the once large genus ''Parmelia'' has been divided into a number of smaller genera according to thallus morphology and phylogenetic relatedness. It is a foliaceous lichen, resembling a leaf in shape. The ends of the leaf-like lobes are often squarish-tipped. The upper surface is pale bluish-gray ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmotrema Tinctorum
''Parmotrema tinctorum'' is a lichen which belongs to the ''Parmotrema ''Parmotrema'' is a genus of lichen belonging to the family Parmeliaceae. It is a large genus, containing an estimated 300 species, with a centre of diversity in subtropical regions of South America and the Pacific Islands. Members of the genus ...'' genus. The lichen is as known as the Palm Ruffle Lichen and is listed as secure by the Nature Conservatory. Description Grows to around 3–30 cm in diameter with board dull smooth slightly shiny gray lobes that are 10–20 mm wide. The underside is black with naked brown areas with a central collection of simple rhizines. Habitat and range Global distribution with a majority of samples being located in North America and Europe. Chemistry Compounds derived from Parmotrema tinctorum have been found to have anti-cancer properties. Environmental monitoring Parmotrema tinctorum has been identified and used as a candidate for monitoring air polluti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochrolechia Parella
''Ochrolechia'' is a genus of crustose lichens in the family Ochrolechiaceae. Species , Species Fungorum accepts 38 species of ''Ochrolechia'': *'' Ochrolechia aegaea'' *'' Ochrolechia africana'' *'' Ochrolechia alaskana'' *'' Ochrolechia alticola'' *'' Ochrolechia androgyna'' *'' Ochrolechia arborea'' *'' Ochrolechia brodoi'' *''Ochrolechia cooperi'' *'' Ochrolechia frigida'' *'' Ochrolechia gyrophorica'' *'' Ochrolechia inaequatula'' *''Ochrolechia incarnata'' *''Ochrolechia insularis'' *''Ochrolechia inversa'' *''Ochrolechia kerguelensis'' *''Ochrolechia lijiangensis'' *''Ochrolechia longispora'' *''Ochrolechia macrosperma'' *''Ochrolechia microstictoides'' *''Ochrolechia minuta'' *''Ochrolechia neoisidiata'' *'' Ochrolechia pallenti-isidiata'' *'' Ochrolechia pallescens'' *'' Ochrolechia parella'' *'' Ochrolechia pseudotartarea'' *'' Ochrolechia rhodoleuca'' *'' Ochrolechia rugomarginata'' *'' Ochrolechia splendens'' *'' Ochrolechia subathallina'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
