{ "@graph" : [ { "@id" : "http://semantics.gr/authorities/EKT-voc-classifier/1979939659", "@type" : "skos:Concept", "broader" : "http://semantics.gr/authorities/EKT-voc-classifier/1048745754", "exactMatch" : [ "http://id.loc.gov/authorities/subjects/sh85054037", "http://semantics.gr/authorities/EKT-voc/1979939659", "http://vocabularies.unesco.org/thesaurus/concept159" ], "note" : { "@language" : "en", "@value" : "isi - Geology covers resources that deal with the physical history of the Earth, the rock of which it is composed, and the physical changes (not the physics) that the Earth has undergone or is undergoing. Resources in this category cover sedimentology, stratigraphy, hydrogeology, ore geology, structural geology, regional geology, and petrology. These resources are somewhat narrow in scope and are not given to the interdisciplinary study of the Earth Sciences." }, "prefLabel" : [ { "@language" : "en", "@value" : "Geology" }, { "@language" : "el", "@value" : "Γεωλογία" } ] }, { "@id" : "http://semantics.gr/authorities/openarchives-item-types/Journal-part", "@type" : "skos:Concept", "broader" : "http://semantics.gr/authorities/openarchives-item-types/Issue-segment", "prefLabel" : [ { "@language" : "en", "@value" : "Publication in journal" }, { "@language" : "el", "@value" : "Δημοσίευση σε περιοδικό" } ] }, { "@id" : "http://semantics.gr/authorities/openarchives-item-types/Scientific-article", "@type" : "skos:Concept", "broader" : "http://semantics.gr/authorities/openarchives-item-types/arthro", "prefLabel" : [ { "@language" : "en", "@value" : "Scientific article" }, { "@language" : "el", "@value" : "Επιστημονικό άρθρο" } ] }, { "@id" : "https://www.openarchives.gr/aggregator-openarchives/edm/aggregation/provider/000024-10442_12819%231", "@type" : "ore:Aggregation", "aggregatedCHO" : "https://www.openarchives.gr/aggregator-openarchives/edm/helios/000024-10442_12819", "dataProvider" : "Εθνικό Ίδρυμα Ερευνών (ΕΙΕ)", "isShownAt" : "https://helios.eie.gr/helios/handle/10442/12819", "provider" : "Greek Aggregator OpenArchives.gr | National Documentation Centre (EKT)" }, { "@id" : "https://www.openarchives.gr/aggregator-openarchives/edm/helios/000024-10442_12819", "@type" : "edm:ProvidedCHO", "creator" : [ "Χρυσικός, Γεώργιος Δ.", "Suarez, Mercedes", "Γκιώνης, Βασίλης", "Kacandes, George H.", "Del Rio, Manuel Sanchez", "Stathopoulou, Elizabeth T.", "Garcia-Romero, Emilia" ], "description" : [ "The mixed dioctahedral-trioctahedral character of Mg-rich palygorskite has been previously described by the formula yMg(5)Si(8)O(20)(OH)(2)(OH(2))(4)center dot(1-y)[xMg(2)Fe(2)center dot(1-x) Mg(2)Al(2)]Si(8)O(20)(OH)(2)(OH(2))(4), where y is the trioctahedral fraction of this two-chain ribbon mineral with an experimentally determined upper limit of y approximate to 0.5 and x is the Fe(III) content in the M2 sites of the dioctahedral component. Ideal trioctahedral (y = 1) palygorskite is elusive, although sepiolite Mg(8)Si(12)O(30)(OH)(4)(OH(2))(4) with a similar composition, three-chain ribbon structure and distinct XRD pattern is common. A set of 22 samples identified by XRD as palygorskite and with variable composition (0 < x < 0.7 < 0 < y < 0.5) were studied to extrapolate the structure of an ideal trioctahedral (y = 1) palygorskite and to compare this structure to sepiolite. Near-infrared spectroscopy was used to study the influence of octahedral composition on the structure of the TOT ribbons, H(2)O in the tunnels and surface silanols of palygorskite, as well as their response to loss of zeolitic H(2)O. All spectroscopic evidence suggests that palygorskite consists of discrete dioctahedral and trioctahedral entities. The dioctahedral entities have variable structure determined solely by x = Fe(III)/(Al+Fe(III)) and their content is proportional to (1-y). In contrast, the trioctahedral entities have fixed octahedral composition or ribbon structure and are spectroscopically identical to sepiolite. The value of d(200) in palygorskite follows the regression d(200)(angstrom) 6.362 + 0.129 x(1-y) + 0.305y, R(2) = 0.96, sigma = 0.013 angstrom. When extrapolated to y = 1, d(200) is identical to sepiolite. Based on this analysis, we propose that palygorskite samples with non-zero trioctahedral character should be considered as members of a polysomatic series of sepiolite and (dioctahedral) palygorskite described by the new formula y'Mg(8)Si(12)O(30)(OH)(4)(OH(2))(4)center dot(1-y')[x'Mg(2)Fe(2)center dot(1-x')Mg(2)Al(2)]Si(8)O(20)(OH)(2)(OH(2))(4), with 0 < x' = x < 0.7 and 0 < y' = y/(2-y) < 0.33.", "Stuttgart" ], "format" : "567-576", "identifier" : [ "https://hdl.handle.net/10442/12819", "0935-1221", "10.1127/0935-1221/2011/0023-2112" ], "language" : "eng", "publisher" : "East Schweizerbartsche Verlags", "rights" : [ { "@language" : "en", "@value" : "© E SCHWEIZERBARTSCHE VERLAGS" }, "© E SCHWEIZERBARTSCHE VERLAGS" ], "source" : "European Journal of Mineralogy", "subject" : [ "polysomatism", "palygorskite", { "@id" : "http://semantics.gr/authorities/EKT-voc-classifier/1979939659" }, "near-infrared spectroscopy", "dioctahedral", "XRD", "sepiolite", "trioctahedral", "Mineralogy" ], "title" : "Trioctahedral entities in palygorskite: Near-infrared evidence for sepiolite-palygorskite polysomatism", "type" : [ "http://semantics.gr/authorities/openarchives-item-types/Journal-part", "http://semantics.gr/authorities/openarchives-item-types/Scientific-article" ], "dc:type" : "Άρθρο σε επιστημονικό περιοδικό", "created" : "2011-07" } ], "@context" : { "note" : { "@id" : "http://www.w3.org/2004/02/skos/core#note" }, "exactMatch" : { "@id" : "http://www.w3.org/2004/02/skos/core#exactMatch", "@type" : "@id" }, "broader" : { "@id" : "http://www.w3.org/2004/02/skos/core#broader", "@type" : "@id" }, "prefLabel" : { "@id" : "http://www.w3.org/2004/02/skos/core#prefLabel" }, "identifier" : { "@id" : "http://purl.org/dc/elements/1.1/identifier" }, "title" : { "@id" : "http://purl.org/dc/elements/1.1/title" }, "creator" : { "@id" : "http://purl.org/dc/elements/1.1/creator" }, "publisher" : { "@id" : "http://purl.org/dc/elements/1.1/publisher" }, "type" : { "@id" : "http://purl.org/dc/elements/1.1/type", "@type" : "@id" }, "subject" : { "@id" : "http://purl.org/dc/elements/1.1/subject" }, "source" : { "@id" : "http://purl.org/dc/elements/1.1/source" }, "rights" : { "@id" : "http://purl.org/dc/elements/1.1/rights" }, "language" : { "@id" : "http://purl.org/dc/elements/1.1/language" }, "description" : { "@id" : "http://purl.org/dc/elements/1.1/description" }, "format" : { "@id" : "http://purl.org/dc/elements/1.1/format" }, "created" : { "@id" : "http://purl.org/dc/terms/created" }, "provider" : { "@id" : "http://www.europeana.eu/schemas/edm/provider" }, "isShownAt" : { "@id" : "http://www.europeana.eu/schemas/edm/isShownAt", "@type" : "@id" }, "dataProvider" : { "@id" : "http://www.europeana.eu/schemas/edm/dataProvider" }, "aggregatedCHO" : { "@id" : "http://www.europeana.eu/schemas/edm/aggregatedCHO", "@type" : "@id" }, "ore" : "http://www.openarchives.org/ore/terms/", "owl" : "http://www.w3.org/2002/07/owl#", "svcs" : "http://rdfs.org/sioc/services#", "skos" : "http://www.w3.org/2004/02/skos/core#", "rdfs" : "http://www.w3.org/2000/01/rdf-schema#", "rdaGr2" : "http://rdvocab.info/ElementsGr2/", "edm" : "http://www.europeana.eu/schemas/edm/", "ekt" : "https://www.semantics.gr/authorities/schemanamespaces/ekt#", "doap" : "http://usefulinc.com/ns/doap#", "rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#", "xalan" : "http://xml.apache.org/xalan", "dcterms" : "http://purl.org/dc/terms/", "wgs84_pos" : "http://www.w3.org/2003/01/geo/wgs84_pos#", "foaf" : "http://xmlns.com/foaf/0.1/", "crm" : "http://www.cidoc-crm.org/rdfs/cidoc_crm_v5.0.2_english_label.rdfs#", "dc" : "http://purl.org/dc/elements/1.1/" } }