Academic literature on the topic 'Transitional to OIB-type compositions'
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Journal articles on the topic "Transitional to OIB-type compositions"
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Halama, Ralf, Jean-Louis Joron, Benoît Villemant, Gregor Markl, and Michel Treuil. "Trace element constraints on mantle sources during mid-Proterozoic magmatism: evidence for a link between the Gardar (South Greenland) and Abitibi (Canadian Shield) mafic rocks." Canadian Journal of Earth Sciences 44, no. 4 (April 1, 2007): 459–78. http://dx.doi.org/10.1139/e06-108.
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Trace and major element compositions of mid-Proterozoic (1.20–1.16 Ga) basaltic lava flows and dikes from the Gardar Province (South Greenland) provide evidence for two geochemically distinct magma sources. Based on distinct features of incompatible trace element ratios, such as Th/Ta, Th/Tb, or Th/Hf, they differ by the composition of their mantle source and by their partial melting trends. One mantle source is compositionally transitional between mid-ocean ridge basalt (MORB)-type and ocean-island basalt (OIB)-type sources with relatively low Ta/Hf ratios (~0.2), moderate enrichment in light rare-earth elements (LREE), and slightly positive initial εNd values (+2). It can be attributed to either a lithospheric mantle source or a depleted astenospheric mantle plume component that has been enriched shortly prior to eruption. The other mantle source is characterized by high Ta/Hf ratios (~0.6), a more pronounced LREE enrichment, and initial εNd values around 0. Elevated CeN/YbN (7.0–9.8) and TbN/YbN ratios (1.6–1.8) of the rocks derived from this source indicate the presence of garnet during melting, suggesting melt generation at depths > 70 km. This mantle source has the geochemical characteristics of an OIB-type source and is interpreted as originating from a mantle plume. Samples from the slightly younger (1.14 Ga) Abitibi dike swarm (Superior Province, Canada), spatially connected to the Gardar Province, show very similar trace element characteristics and the same two distinct magma sources can be identified. The geochemical similarities between the magma sources in South Greenland and Canada support the idea of a genetic link between the two magmatic provinces. This link strengthens the idea that the system was a long-lived major intracontinental rift zone.
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R. Halama, T. Wenzel, B. G. J. Upton, W. Siebel, and G. Markl. "A geochemical and Sr-Nd-O isotopic study of the Proterozoic Eriksfjord Basalts, Gardar Province, South Greenland: Reconstruction of an OIB signature in crustally contaminated rift-related basalts." Mineralogical Magazine 67, no. 5 (October 2003): 831–53. http://dx.doi.org/10.1180/0026461036750147.
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AbstractBasalts from the volcano-sedimentary Eriksfjord Formation (Gardar Province, South Greenland) were erupted at around 1.2 Ga into rift-related graben structures. The basalts have compositions transitional between tholeiite and alkaline basalt with MgO contents <7 wt.% and they display LREE-enrichment relative to a chondritic source. Most of the trace element and REE characteristics are similar to those of basalts derived from OIB-like mantle sources. Initial 87Sr/86Sr ratios of clinopyroxene separates range from 0.70278 to 0.70383 and initial ϵNd values vary from –3.2 to +2.1. The most unradiogenic samples overlap with the field defined by carbonatites of similar age and can be explained by mixing of isotopically depleted and enriched mantle components. Using AFC modelling equations, the Sr-Nd isotope data of the more radiogenic basalts can successfully be modelled by addition of <5% lower crustal granulite-facies gneisses as contaminants. δ18Ov-smow values of separated clinopyroxene range from +5.2 to +6.0% and fall within the range of typical mantle-derived rocks. However, up to 10% mixing with an average lower crustal component are permitted by the data.
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ALDANMAZ, E., M. K. YALINIZ, A. GÜCTEKIN, and M. C. GÖNCÜOĞLU. "Geochemical characteristics of mafic lavas from the Neotethyan ophiolites in western Turkey: implications for heterogeneous source contribution during variable stages of ocean crust generation." Geological Magazine 145, no. 1 (November 30, 2007): 37–54. http://dx.doi.org/10.1017/s0016756807003986.
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AbstractThe Late Triassic to Late Cretaceous age mafic lavas from the Neotethyan suture zone ophiolites in western Turkey exhibit a wide diversity of geochemical signatures, indicating derivation from extremely heterogeneous mantle sources. The rocks as a whole can be divided into three broad subdivisions based on their bulk-rock geochemical characteristics: (1) mid-ocean ridge basalts (MORB) that range in composition from light rare earth element (LREE)-depleted varieties (N-MORB; (La/Sm)N<1) through transitional MORB to LREE enriched types (E-MORB; (La/Sm)N>1); (2) the ocean island basalt (OIB)-type alkaline volcanic rocks with significant enrichment in LILE, HFSE and L-MREE, and a slight depletion in HREE, relative to normal mid-ocean ridge basalts (N-MORB); and (3) the supra-subduction zone (SSZ)-type tholeiites originated from arc mantle sources that are characterized by selective enrichments in fluid-soluble large ion lithophile elements (LILE) and LREE relative to the high field strength elements (HFSE). The formation of MORB tholeiites with variable enrichments and depletions in incompatible trace elements is probably related to the processes of crust generation along an oceanic spreading system, and the observed MORB–OIB associations can be modelled by heterogeneous source contribution and mixing of melts from chemically discrete sources from sub-lithospheric reservoirs. Evaluation of trace element systematics shows that the inferred heterogeneities within the mantle source regions are likely to have originated from continuous processes of formation and destruction of enriched mantle domains by long-term plate recycling, convective mixing and melt extraction. The origin of SSZ-type tholeiites with back-arc basin affinities, on the other hand, can be attributed to the later intra-oceanic subduction and plate convergence which led to the generation of supra-subduction-type oceanic crust as a consequence of imparting a certain extent of subduction component into the mantle melting region. Mixing of melts from a multiply depleted mantle source, which subsequently received variable re-enrichment with a subduction component, is suggested to explain the generation of supra-subduction-type oceanic crust. The geodynamic setting in which much of the SSZ-type ophiolitic extrusive rocks from western Turkey were generated can be described as an arc-basin system that is characterized by an oceanic lithosphere generation most probably associated with melting of mantle material along a supra-subduction-type spreading centre.
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Khudoley, Andrey K., Andrei V. Prokopiev, Kevin R. Chamberlain, Aleksandr D. Savelev, Richard E. Ernst, Sergey V. Malyshev, Artem N. Moskalenko, and Olga Yu Lebedeva. "Late Ordovician Mafic Magmatic Event, Southeast Siberia: Tectonic Implications, LIP Interpretation, and Potential Link with a Mass Extinction." Minerals 10, no. 12 (December 10, 2020): 1108. http://dx.doi.org/10.3390/min10121108.
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A geochronological, isotopic, and geochemical study of the Suordakh event of mafic magmatic intrusions on the southeast Siberian margin was undertaken. U-Pb baddeleyite dating of a mafic sill intruding lower Cambrian rocks, yielded a 458 ± 13 Ma emplacement age. The chemical composition and stratigraphic setting of this dated sill differed from that previously attributed to the Suordakh event, implying that additional intrusions, previously mapped as Devonian, potentially belonged to the Suordakh event. No correlation between L.O.I. and concentration of highly mobile major and trace elements was documented, showing small or no influence of hydrothermal alteration on the chemical composition of the intrusions. A new tectonic reconstruction located an island arc and active margin relatively close to the study area. However, all samples had chemical compositions close to that of OIB and did not display Ta-Nb and Ti-negative anomalies, nor other features typical for subduction-related magmatism. The major and trace element distribution was most characteristic of within-plate basalts with the mantle source composition being transitional from spinel to garnet lherzolite. Combining four U-Pb baddeleyite dates of mafic sills and dykes from southeast Siberia, the age of the Suordakh event was estimated at 454 ± 10 Ma. The area of the Suordakh event was at least 35,000–40,000 km2 (an estimate including sills previously interpreted as Devonian), and could be increased with additional dating in Southeastern Siberia. Similar ages for within-plate intrusions were reported from South Korea, West Mongolia, South Argentina, North Iran and Northwest Canada, and these ca. 450 Ma ages were collectively close in timing with the latest Ordovician (Hirnantian) mass extinction. More high-precision dating is necessary to fully test a link between the Suordakh event (and the other age-correlative events) and the end-Ordovician mass extinction.
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Chandra, Rakesh, Rajeev Upadhyay, and Anshu K. Sinha. "Subduction and collision related magmatism in the Shyok Suture and eastern Karakoram." Journal of Palaeosciences 48, no. (1-3) (December 31, 1999): 183–209. http://dx.doi.org/10.54991/jop.1999.1303.
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The Shyok Suture is represented by distinct sets of volcano-plutonic rock assemblages. The high-Mg tholeiitic basalt and calc-alkaline andesites of the Shyok Volcanics have a subduction zone chemical signature. The REE data on tholeiitic basalt suggest a chemical affinity between primitive N-MORB to E-MORB. The calc-alkaline andesites, however, resembles to transitional nature of basalt between E-MORB to OIB. The geochemical data and regional tectonic setting suggest a close similarity between the Shyok Volcanics of northern Ladakh and the Chalt Volcanics of Kohistan.
The mildly deformed trondhjemite-tonalite-granodiorite of the Tirit Granitoids are composite plutons located south of the Shyok Suture melange. These granitoids are subalkaline, I-type and represented by volcanic arc chemical signatures. The regional tectonic setting, the nature of occurrence and the composition of Tirit Granitoids are similar to the plutonic suites of northern Kohistan (Gindai, Matum Das and Nomal plutons).
The eastern Karakoram Batholith is dominated by quartz monzonite-tonalite-granodiorite and granite. The subalkaline to calc-alkaline Karakoram Batholith is constituted by both I-and S-type granitoids with volcanic arc and syn-collision chemical signatures. REE data suggest that the I-type granitoids of eastern Karakoram are calc-alkaline magmatism of a subduction zone environment. In contrast, most of the S-type granitoids are crust-derived peraluminous granitoids. New Rb/Sr isotopic whole rock age data indicates that an S-type intrusive phase was active in the eastern Karakoram region during 83±9 Ma. The syn-collision nature of these granitoids are similar to those of north Sost pluton and Karambar pluton of northern Kohistan.
This indicates that the collision between Kohistan-Ladakh arc and Karakoram block was active during 83±9 Ma.
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Wang, Qing, Zhao Yang Ding, Jing Da, Kun Ran, and Zhi Tong Sui. "Factors Influencing Bonding Strength of Geopolymer-Aggregate Interfacial Transition Zone." Advanced Materials Research 224 (April 2011): 1–7. http://dx.doi.org/10.4028/www.scientific.net/amr.224.1.
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Fundamental studies on geopolymer are increased rapidly because of its potential commercial applications. However, little work has been done on the relationship of the interfacial transitional zone between geopolymer and aggregate and its influence on the final chemical and physical properties of geopolymeric products derived from waste materials. In this paper, factors that influencing the interfacial transition zone of geopolymer concrete such as the type of the aggregate and the oxide compositions of raw materials was studied. The microstructure was also observed through relative devices. The presented results show that bonding strength of geopolymer-marble interfacial transitional zone, of which the 28d bonding strength reached up to 7.9 MPa, was higher than that of geopolymer-granite. The bonding strength of geopolymer-marble/geopolymer-granite interfacial transitional zone increased and finally reached up to 7.9 MPa/4.3 MPa with the molar ratio of n(SiO2)/n(Al2O3) increased within the range of 2.6～2.9. Both geopolymer-marble and geopolymer-granite bonding strength decreased as the molar ratio of n(SiO2)/ n(Na2O) increased. The mechanical properties of interfacial transitional zone between geopolymer and stone were affected by the oxide component of the geopolymer and the type of the raw materials.
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BRIAND, BERNARD, JEAN-LUC BOUCHARDON, PAUL CAPIEZ, and MICHEL PIBOULE. "Felsic (A-type)–basic (plume-induced) Early Palaeozoic bimodal magmatism in the Maures Massif (southeastern France)." Geological Magazine 139, no. 3 (May 2002): 291–311. http://dx.doi.org/10.1017/s0016756802006477.
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The Maures Massif forms an important piece of the southernmost part of the Variscan belt of western Europe. This massif exhibits high-grade bimodal felsic–basic volcanic complexes, a distinctive lithological feature documented elsewhere in similar domains of the European Variscides and referred to the Cambro-Ordovician extensional episode. Two major alkalic and tholeiitic compositional groups and subordinate transitional metabasites have been identified, occurring at several distinct horizons or in bimodal complexes. This chemical diversity is interpreted in terms of variable degrees of partial melting of progressively depleted mantle source(s), which experienced melting at different depths, from garnet to spinel stability domains, during a progressive mantle upwelling associated with intracontinental rifting. This setting is reinforced by the presence of metabasites with compositions similar to continental flood basalts, showing slightly humped REE patterns, and interpreted as resulting from the melting of a partially depleted source at a relatively low degree of melting, in the garnet–spinel transition zone. The metafelsites from the tholeiitic bimodal complex exhibit the distinctive major and trace element characteristics of A-type rhyolites. Their elemental variations are consistent with fractional crystallization of major and accessory phases, but some discontinuous REE profiles result from a hydrothermal fractionation mechanism. The modelling of common anhydrous fractionating assemblages suggests that these A-type compositions may be derived from the associated tholeiites by extensive degrees of fractionation (90 %) with some continental crust involvement, or by anhydrous partial melting (∼30 %) of an underplated mafic parent of tholeiitic composition. The bimodal character of the Late Cambrian Maures magmatism, together with the chemistry of the various metabasites and metafelsites, suggests plume-induced intracontinental magmatic activity, resulting in lithospheric thinning prior to the onset of rifting and break-up of the Palaeozoic continental lithosphere, at this northern margin of Gondwana.
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Slovenec, Damir, Boško Lugović, and Irena Vlahović. "Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW External-Internal Dinarides junction (Croatia)." Geologica Carpathica 61, no. 4 (August 1, 2010): 273–92. http://dx.doi.org/10.2478/v10096-010-0016-1.
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Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW External-Internal Dinarides junction (Croatia)At the NW inflexion of the Sava-Vardar Suture Zone ophiolite mélanges, known as the Kalnik Unit, form the surface of the slopes of several Pannonian inselbergs in the SW Zagorje-Mid-Transdanubian Zone. The Mt Samoborska Gora ophiolite mélange, thought to be a part of the Kalnik Unit, forms a separate sector obducted directly onto Dinaric Triassic carbonate sediments. Basaltic rocks, the only magmatic rocks incorporated in the mélange, include Middle-Triassic (Illyrian-Fassanian) alkali within-plate basalts and Middle Jurassic (uppermost Bathonian-Lower Callovian) tholeiitic basalts. The latter sporadically constitute composite olistoliths, and are geochemically divided into N-MORB-like (high-Ti basalts) and transitional MORB/IAT (medium-Ti basalts). These geochemically different rocks suggest crystallization at various tectonomagmatic settings, which is also indicated by the rock paragenesis and host clinopyroxene compositions. Alkali basalts reflect melts derived from an OIB-type enriched mantle source [Ti/V= 62.2-82.4; (La/Lu)cn= 6.4-12.8] with Nd-Sr isotope signatures close resembling the Bulk Earth [εNd(T=235 Ma)= + 1.6 to + 2.5]. They are recognized as preophiolite continental rift basin volcanic rocks that closely predate the opening of the Repno oceanic domain (ROD) of the Meliata-Maliac ocean system. The high-Ti and medium-Ti basalts from composite blocks derived from a similar depleted mantle source (εNd(T=165 Ma) = + 6.01 vs. + 6.35) succesively metasomatized by expulsion of fluids from a subducting slab leading to a more pronounced subduction signature in the latter [Ti/V=31.6-44.8 and (Nb/La)n=0.67-0.90 vs. Ti/V=21.5-33.9 and (Nb/La)n=0.32-0.49]. These composite blocks indicate crust formation in an extensional basin spreading over the still active subducting ridge. The majority of high-Ti basalts may represent the fragments of older crust formed at a spreading ridge and incorporated in the mélange of the accretionary wedge formed in the proto-arc-fore-arc region. The Mt Samoborska Gora ophiolite mélange represents the trailing edge of the Kalnik Unit as a discrete sector that records the shortest stage of tectonomagmatic evolution related to intraoceanic subduction in the ROD.
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Anderson, Robert G., Jonah Resnick, James K. Russell, G. J. Woodsworth, Michael E. Villeneuve, and Nancy C. Grainger. "The Cheslatta Lake suite: Miocene mafic, alkaline magmatism in central British Columbia." Canadian Journal of Earth Sciences 38, no. 4 (April 1, 2001): 697–717. http://dx.doi.org/10.1139/e00-121.
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New mapping, mineralogical, and geochemical studies help characterize late Tertiary primitive, alkaline, sodic basanite, alkali olivine basalt, transitional basalt, and diabase in the Nechako River, Whitesail Lake, and McLeod Lake map areas of central British Columbia and distinguish the Miocene Cheslatta Lake suite. The suite encompasses scattered erosional remnants of topographically distinct, columnar-jointed, olivine-phyric basalt and diabase volcanic necks, dykes, and associated lava flows north of the Anahim volcanic belt and west of the Pinchi Fault. Volcanic centres at Alasla Mountain and at Cutoff Creek, near Cheslatta Lake, are proposed as type areas. Olivine, plagioclase, and pyroxene phenocrysts, megacrysts, and (or) xenocrysts; common ultramafic xenoliths; and rare but significant plutonic and metamorphic xenoliths are characteristic. Basanite, transitional basalt, and alkali olivine basalt groundmass contain plagioclase, clinopyroxene, Fe-Ti oxides, feldspathoid, olivine, and apatite. The Cheslatta Lake suite is characterized by its alkaline character, olivine-rich (>10 wt.%) normative mineralogy, and silica-undersaturated nature (>1 wt.% normative nepheline; hypersthene-normative rocks are uncommon). Mg numbers vary between 7242. Some samples encompass near-primitive mantle melt compositions. Cheslatta Lake suite rocks in the Nechako River area are distinguished from the underlying Eocene Endako and stratigraphically higher Neogene Chilcotin groups basaltic andesite lavas within the study area, and from the Chilcotin Group basalt in the type area south of the Anahim volcanic belt, by form, preserved thickness, phenocrystxenocryst mineralogy, amygdule abundance, included xenoliths, isotopic age, and major and incompatible, high field strength, and rare-earth trace element contents.
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Xue, Yuan, Ningyue Sun, and Guowu Li. "Evolution of Nb–Ta Oxide Minerals and Their Relationship to the Magmatic-Hydrothermal Processes of the Nb–Ta Mineralized Syenitic Dikes in the Panxi Region, SW China." Minerals 11, no. 11 (October 29, 2021): 1204. http://dx.doi.org/10.3390/min11111204.
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Previous geochemical and petrological studies have concluded that initially magmatic Nb–Ta mineralization is often modified by post-magmatic hydrothermal fluids; however, there is still a lack of mineralogical evidence for the syenite-related Nb–Ta deposit. From the perspective of Nb–Ta minerals, the pyrochlore supergroup minerals have significance for indicating the fluid evolution of alkaline rock or related carbonatite type Nb–Ta deposits. The Panzhihua–Xichang (Panxi) region is a famous polymetallic metallogenic belt in southwestern China, abound with a huge amount of Nb–Ta mineralized syenitic dikes. This study focuses on the mineral textures and chemical compositions of the main Nb–Ta oxide minerals (including columbite-(Fe), fersmite, fergusonite-(Y), and especially pyrochlore group minerals) in samples from the Baicao and Xiaoheiqing deposits, in the Huili area, Panxi region, to reveal the magma evolution process of syenitic-dike-related Nb–Ta deposits. The Nb–Ta oxides in the Huili syenites are commonly characterized by a specific two-stage texture on the crystal scale, exhibiting a complex metasomatic structure and compositional zoning. Four types of pyrochlore group minerals (pyrochlores I, II, III, and IV) formed in different stages were identified. The euhedral columbite-(Fe), fersmite, and pyrochlores I and II minerals formed in the magmatic fractional crystallization stage. Anhedral pyrochlore III minerals are linked to the activity of magma-derived hydrothermal fluids at the late stages of magma evolution. The pyrochlore IV minerals and fergusonite-(Y) tend to be more concentrated in areas that have undergone strong albitization, which is a typical phenomenon of hydrothermal alteration. These mineralogical phenomena provide strong evidences that the magmatic-hydrothermal transitional stage is the favored model for explaining the Nb–Ta mineralization process. It is also concluded that the changes in chemical composition and texture characteristics for pyrochlore group minerals could serve as a proxy for syenite-related Nb–Ta mineralization processes.
Dissertations / Theses on the topic "Transitional to OIB-type compositions"
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Fanchon, Eric. "Etude structurale de conducteurs ioniques unidimensionnels de type hollandite." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37604938h.
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Saifi, Ali. "Contribution à l'étude des propriétés magnétiques des systèmes spinelles isolants CdCr2xIn2-2xS4 et ZnCr2xGa2-2xO4 : phases type verre de spin." Paris 6, 1986. http://www.theses.fr/1986PA066519.
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Ces systèmes présentent la percolation et la frustration. Le premier composé est ferromagnétique, tandis que le second présente des interactions antiferromagnétiques. On étudie en fonction de x les transitions de ces composés. Les transitions de phase du gallate ont été étudiées par effet Mössbauer. On a mis en évidence que pour x0,75 l'ordre magnétique tend vers un ordre caractéristique de la "vraie" phase verre de spin.
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Bacher, Patrice. "Etude du profil des raies de diffraction neutronique en temps de vol utilisant un obturateur statistique : application à l'étude d'oxynitrures de structure tétraèdrique ou de type pérovskite." Grenoble 1, 1987. http://www.theses.fr/1987GRE10035.
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Application de l'etude du titre a deux grandes famille structurales: (1) les structures tetraedriques derivant de cele de la wuertzite (li::(1,33)ge::(1,67)on::(2); zn::(1,231)ge::(0,689)o::(0,782)n::(1,218); kgeon), (2) les structures de type perovskite (batao::(2)n, banbo::(2)n, lawo::(0,6)n::(2,4))
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Zakhour, Mirvat. "Etudes structurales dans l'approche du formalisme de superespace de nouvelles phases modulées de type composite de la série Ba1+x(A'xB1-x)O3 (0 ≤ x ≤ 1/2 ; A', B = élément de transition d) : relation entre composition et vecteur de modulation." Bordeaux 1, 2000. https://tel.archives-ouvertes.fr/tel-01233754.
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Un modele structural est propose pour decrire les structures d'une famille de composes a chaines unidimensionnelles, derivee de la perovskite 2h, de formulation a 1 + x(a xb 1 x)o 3 (0 x 1/2 ; a = ba, a, b = element de transition d). Chaque membre de cette famille peut etre decrit par un modele structural unique de type composite, dans le formalisme de superespace avec des fonctions de modulation de type creneau pour l'occupation et de type dents de scie pour la position. Le modele ne considere en premiere approximation que deux variables qui sont le vecteur q de modulation qui est lie a la composition x et la difference de hauteur entre prismes et octaedres constituant les chaines (a,b)o 3. Le modele est predictif et permet de decrire toute composition x en suivant la regle de l'arbre de farey. Le modele propose est illustre par les structures de ba 1 + x(ni, pt)o 3 (x = 0. 2124), ba 1 + x(cu xrh 1 x)o 3 (x = 0. 16 et x = 0. 168) et ba 1 + x(cu xir 1 x)o 3 (x = 0. 27). Les resultats obtenus montrent toute la puissance du formalisme de superespace pour de tels systemes ou la modulation est liee a la composition. Cette nouvelle famille constitue un nouvel exemple de phases a composition flexible parfaitement unifiees dans un superespace a 4 dimensions.
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Caignaert, Vincent. "Non-stoechiometrie par creation de lacunes anioniques : oxydes mixtes de manganese et de fer, de structure apparentee a la perovskite." Caen, 1986. http://www.theses.fr/1986CAEN2007.
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Etude des possibilites d'ecarts a la stoechiometrie sur le sous reseau anionique des perovskites amn::(1-x) fe::(x)o::(3-y) (a=ca, sr, ba) par diffraction x et neutron, microscopie electronique haute resolution, spectre moessbauer et mesures magnetiques. Caracterisation de plusieurs types d'ordre des lacunes oxygene en fonction du cation a et du taux de mn
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Er-Rakho, Lahcen. "Oxydes de cuivre a valence mixte : perovskites deficitaires en oxygene." Caen, 1987. http://www.theses.fr/1987CAEN2036.
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Mise en evidence et etude de deux grandes familles de composes dans le systeme la::(2)o::(3)-ao-cuo(a=ca,ba,sr) : la::(2-x)ba::(1-x)cu::(1-x/2)o::(5-x)(ln=la,nd) ou cu est essentiellement au degre d'oxydation 2 et une seconde famille caracterisee par la valence mixte du cuivre, les quantites de cuivre 3 pouvant atteindre dans certains cas 40%. Tous ces oxydes ont en commum leur appartenance a la structure perovskite. Proprietes electriques et magnetiques
Books on the topic "Transitional to OIB-type compositions"
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Mattissen, Johanna. Sub-Types of Polysynthesis. Edited by Michael Fortescue, Marianne Mithun, and Nicholas Evans. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199683208.013.5.
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The structural heterogeneity of polysynthetic languages is captured by a sublassification of allegedly polysynthetic languages according to their word-formational type (number of roots allowed in a verb form), namely, compositional, transitional, or affixal, and their internal organization (template vs. scope or both). Further parameters show correlations to these independent ones: the number of participants encoded on a verb, the imaginable evolutionary path via which the structure has come about, namely layering (“onion type”), internal expansion (“sandwich type”) or coalescence (“burdock type”), and the characteristic design of a complex verb form: Grammatical category accumulation (integration of non-obligatory, rather grammatical information); ping-pong recategorization (multiple verbalization and nominalization); productive in/excorporation; dependent-head synthesis; multiple packing (integration of rather lexical information); holophrasis (all wordforms being predicates—or particles); composite-stem layout (composite root-like morphemes, unitary concept); and building-block design (multiple classifer-like morphemes make up a wordform). The classification along these parameters reconciles conflicting approaches to polysynthesis.
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Gooley, Dana. Schumann and the Economization of Musical Labor. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190633585.003.0005.
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Chapter 4 details Robert Schumann’s evolution from an eager and fluent improviser into a composer who advocated writing music away from the piano entirely. His evolution demonstrates the growing polarization between improvisation and composition, modes of music-making that were generally viewed as mutually beneficial until the 1830s. His early, piano-centered output provides clues into how certain transitional and rhetorical strategies were rooted in keyboard improvisational practices, but consciously invested with a “depth” or “psychology” that gave them a romantic cast. The chapter’s interpretive lens is then broadened to consider how Schumann’s anxiety over improvisation was shaped by an “ethos of economy” then common to the educated classes. Improvisation thrived on certain anti-economic impulses—a dilated sense of temporal unfolding, a strenuous type of performer training, a risk of inefficacious communication—that ran counter to bourgeois ethical codes such as the containment of excess and the rational ordering of available resources.
Book chapters on the topic "Transitional to OIB-type compositions"
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Hamdi-Cherif, Meriem, Paul Malliet, Mathieu Plane, Frederic Reynes, Francesco Saraceno, and Alexandre Tourbah. "2. Public Investment and Low-carbon Transition in France." In Greening Europe, 23–40. Cambridge, UK: Open Book Publishers, 2022. http://dx.doi.org/10.11647/obp.0328.02.
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In Chapter 2, M. Hamdi-Cherif, P. Malliet, F. Reynes, M. Plane, F. Saraceno, and A. Tourbah argue that public investment in France has been on a downward trend since 2009, rebounding only in the wake of the COVID-19 crisis, with the objective of supporting global demand and spurring economic growth. The increase in investment, however, is less pronounced than during the global financial crisis. Orienting investment towards low-carbon capital within the framework of a long-term emission reduction goal, despite being unprecedented in history, is also insufficient, especially if its level is not maintained over the coming decades. The type of low-carbon transition strategy chosen—either relying more on technological progress or reaching a significant reduction in energy consumption (a Sobriety scenario)—will noticeably impact the composition and amount of investment needed to meet the targets.
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Laird, James. "A Curry-style Semantics of Interaction: From Untyped to Second-Order Lazy $$\lambda \mu $$-Calculus." In Lecture Notes in Computer Science, 422–41. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45231-5_22.
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AbstractWe propose a “Curry-style” semantics of programs in which a nominal labelled transition system of types, characterizing observable behaviour, is overlaid on a nominal LTS of untyped computation. This leads to a notion of program equivalence as typed bisimulation.Our semantics reflects the role of types as hiding operators, firstly via an axiomatic characterization of “parallel composition with hiding” which yields a general technique for establishing congruence results for typed bisimulation, and secondly via an example which captures the hiding of implementations in abstract data types: a typed bisimulation for the (Curry-style) lazy $$\lambda \mu $$ λ μ -calculus with polymorphic types. This is built on an abstract machine for CPS evaluation of $$\lambda \mu $$ λ μ -terms: we first give a basic typing system for this LTS which characterizes acyclicity of the environment and local control flow, and then refine this to a polymorphic typing system which uses equational constraints on instantiated type variables, inferred from observable interaction, to capture behaviour at polymorphic and abstract types.
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Erbil, Candan, Ezgi Toz, Özgür Akdemir, and Nurseli Uyanık. "An Investigation into the Influence of Crosslinker Type and Solvent Composition on Physical Properties and Phase Transition Behavior of Poly(N-isopropylacrylamide) Hydrogels." In ACS Symposium Series, 167–80. Washington, DC: American Chemical Society, 2010. http://dx.doi.org/10.1021/bk-2010-1051.ch014.
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Trujillo-Reyes, Ángeles, Sofía G. Cuéllar, David Jeison, Antonio Serrano, Soraya Zahedi, and Fernando G. Fermoso. "Anaerobic Digestion of Organic Solid Waste: Challenges Derived from Changes in the Feedstock." In Solid Waste Management - Recent Advances [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.107121.
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Over the years, research on the anaerobic digestion of solid waste has mainly focused on single feedstocks with a fixed composition. Nevertheless, the impact assessment that drastic changes in the type and composition of feedstock might have on AD process stability has not been investigated in depth. The existence of a wide variety of organic solid waste whose generation and composition are highly dependent on seasonality, just as the possibility of using treatment plant facilities already in operation for treating new waste, makes it necessary to improve our knowledge of transitory states in AD. This chapter aims to provide insight into research on transitory states during the AD process when the type or composition of the feedstock has suffered a change to assess whether the AD process was finally able to adapt to system disturbances. Information about process stability control and microbial population adaptation, among others, derived from the transition states will be addressed.
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"Polytopes Dual to Higher-Dimensional Polytopes." In The Classes of Higher Dimensional Polytopes in Chemical, Physical, and Biological Systems, 221–53. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8374-6.ch008.
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The transitions from regular and semi-regular polytopes of various dimensions to dual polytopes are considered in detail. It is shown that any deviation of polytopes from the correct forms leads, in their dual modifications, to new classes of polytopes. Polytopes dual to the products of polytopes form the class of polyincidental polytopes. Their images are given, and their composition is precisely indicated. For example, the polytope dual to the product of a decagon and a decagon contains 100 tetrahedra. All of them are listed by vertices in the dual polytope. Regularly faceted polytopes with a large number of different types of gonohedrons (polytypichedron and polytypictops) for dual transitions form a new class of polytopes with faces of irregular shape and, accordingly, a new type of gonohedron. This can be important in the analysis of chemical structures, often characterized by deviations from regular geometric shapes.
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Peters, Debra P. C., and Robert P. Gibbens. "Plant Communities in the Jornada Basin: The Dynamic Landscape." In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0014.
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Plant communities of the Jornada Basin are characteristic of the northern Chihuahuan Desert both in structure and dynamics. Although a number of plant communities can be differentiated, five major vegetation types are often distinguished that differ in plant species cover and composition, as well as other factors, such as animal populations, soil properties, and elevation. These five types are black grama (Bouteloua eriopoda) grasslands, playa grasslands, tarbush (Flourensia cernua) shrublands, creosotebush (Larrea tridentata) shrublands, and mesquite (Prosopis grandulosa) shrublands. Similar to many other parts of the Chihuahuan Desert, these plant communities have experienced major shifts in vegetation composition over the past 50–150 years (York and Dick-Peddie 1969). The most dramatic changes in vegetation and associated ecosystem processes have occurred as a result of a shift in life form due to woody plant encroachment into perennial grasslands (Grover and Musick 1990; Bahre and Shelton 1993). This encroachment of shrubs has occurred in many arid and semiarid regions of the world, including the Western United States, northern Mexico, southern Africa, South America, New Zealand, and Australia (McPherson 1997; Scholes and Archer 1997). A number of drivers have been implicated in these grass–shrub dynamics, including various combinations of livestock grazing, small animal activity, drought, changes in fire regime, and changes in climate (Humphrey 1958; Archer 1989; Allred 1996; Reynolds et al. 1997; Van Auken 2000). The causes of shrub invasion are quite variable and often poorly understood, although the consequences consistently lead to the process of desertification (Schlesinger et al. 1990). This chapter describes the characteristics of each vegetation type and the documented changes in each type at the Jornada Basin. We then discuss the key drivers influencing these dynamics. Vegetation in the Chihuahuan Desert region has been classified as desert-grassland transition (Shreve 1917), desert savanna (Shantz and Zon 1924), desert plains grasslands (Clements 1920), desert shrub grassland (Darrow 1944), and shrubsteppe (Kuchler 1964). Desert grassland is often used as a general descriptive name for the area (McClaran 1995), although landscapes at the Jornada and throughout the northern Chihuahuan Desert often consist of a mosaic of desert grasslands, Chihuahuan Desert shrublands, and plains-mesa sand scrub (Dick-Peddie 1993).
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Corrigan, D., and D. Van Rooyen. "Paleoproterozoic Earth and the transition toward modern tectonic processes: A synopsis." In Laurentia: Turning Points in the Evolution of a Continent. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.1220(04).
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ABSTRACT Many of the hallmarks of modern plate-tectonic processes first occurred in the Paleoproterozoic Era, indicating that the mechanical, thermal, and compositional parameters of Earth’s lithosphere had evolved to approximately modern ranges of values by that time. The core of Laurentia preserves widespread examples of both convergent and divergent tectonic processes in the time span from 2.2 to 1.7 Ga, particularly within the Trans-Hudson composite orogen. Large continental masses or supercontinents previously accreted during the Neoarchean Era began to break up between 2.4 and 2.0 Ga, leading to the deposition of widespread passive-margin sedimentary prisms and locally voluminous emplacement of mafic magma in radiating dike swarms. Further rifting and drifting led to the formation of incipient (e.g., Bravo Formation) to fully developed oceanic crust (e.g., Manikewan Ocean). Plate convergence beginning ca. 1.92 Ga heralded the demise of the Manikewan Ocean ~150 m.y. after its postulated opening. Protracted subduction of oceanic lithosphere over a period of ~90 m.y. produced a series of island arcs, some of which (Lynn Lake, Flin Flon, Snow Lake) host world-class volcanogenic massive sulfide (VMS) ± Au deposits. Plate convergence also led to progressive southeastward (present-day coordinates) accretion of microplates on a pre-amalgamated core consisting of the Slave craton and the Rae and Hearne “Provinces,” forming the Churchill plate. Following the formation of the Churchill plate collage ca. 1.86 Ga, subduction of oceanic lithosphere organized along an ~4000-km-long, north-dipping subduction zone along the southeastern edge of the Churchill plate, producing voluminous continental arc magmas in an Andean-type setting. The final phase of tectonic evolution involved collision of the Superior and North Atlantic cratons with the Churchill plate and intervening juvenile oceanic arc terranes. That phase was strongly influenced by the irregular shape of the indenting Superior craton, favoring the development of oroclines and leading to escape tectonics and lateral extrusion of continental microplates. For the most part, the Trans-Hudson was a hot but not necessarily thick orogen, perhaps reflecting a higher geothermal gradient during the Paleoproterozoic Era.
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Mogk, David W., Carol D. Frost, Paul A. Mueller, B. Ronald Frost, and Darrell J. Henry. "Crustal genesis and evolution of the Archean Wyoming Province: Continental growth through vertical magmatic and horizontal tectonic processes." In Laurentia: Turning Points in the Evolution of a Continent. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.1220(01).
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ABSTRACT The Archean Wyoming Province formed and subsequently grew through a combination of magmatic and tectonic processes from ca. 4.0 to 2.5 Ga. Turning points in crustal evolution are recorded in four distinct phases of magmatism: (1) Early mafic magmatism formed a primordial crust between 4.0 and 3.6 Ga and began the formation of a lithospheric keel below the Wyoming Province in response to active plume-like mantle upwelling in a “stagnant lid”–type tectonic environment; (2) earliest sialic crust formed in the Paleoarchean by melting of hydrated mafic crust to produce rocks of the tonalite-trondhjemite-granodiorite (TTG) suite from ca. 3.6 to 2.9 Ga, with a major crust-forming event at 3.3–3.2 Ga that was probably associated with a transition to plate tectonics by ca. 3.5 Ga; (3) extensive calc-alkalic magmatism occurred during the Mesoarchean and Neoarchean (ca. 2.85–2.6 Ga), forming plutons that are compositionally equivalent to modern-day continental arc plutons; and (4) a late stage of crustal differentiation occurred through intracrustal melting processes ca. 2.6–2.4 Ga. Periods of tectonic quiescence are recognized in the development of stable platform supracrustal sequences (e.g., orthoquartzites, pelitic schists, banded iron formation, metabasites, and marbles) between ca. 3.0 and 2.80 Ga. Evidence for late Archean tectonic thickening of the Wyoming Province through horizontal tectonics and lateral accretion was likely associated with processes similar to modern-style convergent-margin plate tectonics. Although the province is surrounded by Paleoproterozoic orogenic zones, no post-Archean penetrative deformation or calc-alkalic magmatism affected the Wyoming Province prior to the Laramide orogeny. Its Archean crustal evolution produced a strong cratonic continental nucleus prior to incorporation within Laurentia. Distinct lithologic suites, isotopic compositions, and ages provide essential reference markers for models of assembly and breakup of the long-lived Laurentian supercontinent.
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Kumar Kambila, Vijaya. "Structural, Optical, and Electrical Studies of PAN-Based Gel Polymer Electrolytes for Solid-State Battery Applications." In Management and Applications of Energy Storage Devices. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.98825.
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Gel polymer electrolyte films (GPEs) based on polyacrylonitrile (PAN) complexed with NaF salt and an Al2O3 nanofiller were prepared via solution cast method. Structural studies were performed to investigate the order of conductivity under the influence of salt and nanofillers. The prepared films were characterized using energy dispersive x-ray spectrometry (EDS) to determine the chemical composition in wt%. EDS studies reveal that PAN–NaF with Al2O3 ceramic filler decreases the degree of crystallinity with increasing concentration of the nanofiller. The UV–Vis spectrum was recorded by a Hewlett-Packard HP8452A diode array spectrometer. The structural effect of salt and nanoparticles on the conductivity was also confirmed by UV–Vis spectroscopy. The mechanical properties of the prepared polymer electrolytes were determined using a Universal Tensile Machine (Instron Model 5565, Canada) with a constant crosshead speed of 10 mm/min. The addition of nanoparticles increased both the modulus and the strength of the polymer nanocomposites. Both the tensile strength and Young’s modulus increased with increasing functionalized nanoparticle loading. The change in transition temperature caused by the incorporation of the Al2O3 nanofiller and plasticizer into the PAN+NaF complex was studied by differential scanning calorimetry (DSC) analysis. Additionally, DSC thermograms were recorded to measure the glass transition temperature and melting temperature of PAN-based electrolytes using a Mettler instrument. Conductivity studies were carried out for all the prepared polymer electrolytes to understand the conduction mechanism. The role of the ceramic phase is to reduce the melting temperature, which is ascertained from DSC. The sample containing PAN:NaF (70:30) exhibits the highest conductivity of 1.82 x 10−4 S cm−1 at room temperature (303 K) and 2.96 x 10−3 S cm−1 at 378 K. The polymer electrolytes considered in the present study exhibited an Arrhenius type of conduction. The polymer electrolyte containing 3 wt% Al2O3 nanofiller showed an ionic conductivity of 5.96 × 10−3 S cm−1. To determine transfer numbers, Wagner’s polarization method can be used. From these studies, it is observed that the conduction mechanism is predominantly due to ions. Using this (PAN–NaF– Al2O3) (70:30:3) electrolyte, a solid-state electrochemical cell was fabricated, and its discharge profiles were studied under a constant load of 100 kΩ. Finally, several cell profiles associated with this cell were evaluated and reported.
Conference papers on the topic "Transitional to OIB-type compositions"
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Seilert, Julia, and Eckhard Floter. "Relating polymorphic transition and triglyceride composition." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uiuq2084.
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Structuring fats are complex triglyceride (TAG) mixtures characterized by diverse crystallization events. These range from co- and subsequent crystallization of different fractions determined by the mixture's phase behavior, i.e., solid immiscibility, to polymorphism shaping the overall crystallization kinetics. The kinetics behind polymorphism differ depending on TAG type and fractions, complicating this even more. Several experimental studies have shown that multiple-step crystallization takes place, in which, in most cases, the first step is assigned to the formation of α-crystals followed by melt-mediated β' crystallization - the latter being the so-called polymorphic transition. Both are important in fats processing utilizing a combination of shear with rapid cooling, e.g., in a scraped surface heat exchanger. This obeys highly dynamic conditions often not captured using standard methods, e.g., Differential Scanning Calorimetry, rheology, XRD, leading to even more complex crystallization phenomena unexplored. In search of new techniques, the evaluation of measurements must be undertaken with care with regard to the TAG composition. This contribution presents a first step towards linking the TAG molecular composition to characteristic crystallization events observed using varying techniques in the static and dynamic mode. Using model systems of varying TAG fractions with different melting characteristics, the contributions to the described crystallization kinetics are discussed.
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Dai, Zhaoyi Joey, Amy Kan, Yi-Tsung Alex Lu, Cianna Leschied, Yue Zhao, Chong Dai, Xin Wang, Samridhdi Paudyal, Saebom Ko, and Mason Tomson. "Novel Mineral Scale Deposition Model Under Different Flow Conditions with or Without Scale Inhibitors." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204373-ms.
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Abstract Mineral scale formation causes billions of dollars’ loss every year due to production losses and facility damages in the oil and gas industry. Accurate predictions of when, where, how much, and how fast scale will deposit in the production system and how much scale inhibitor is needed are critical for scale management. Unfortunately, there is not a sophisticated scale deposition model available, potentially due to the challenges below. First, an accurate thermodynamic model is not widely available to predict scale potential at extensive ranges of temperature, pressure, and brine compositions occurring in the oilfield. Second, due to the complex oilfield operation conditions with large variations of water, oil and gas flow rates, tubing size, surface roughness, etc., wide ranges of flow patterns and regimes can occur in the field and need to be covered in the deposition model. Third, how scale inhibitors impact the mineral deposition process is not fully understood. The objective of this study is to overcome these challenges and develop a model to predict mineral deposition at different flow conditions with or without scale inhibitors. Specifically, after decades of efforts, our group has developed one of the most accurate and widely used thermodynamic model, which was adopted in this new deposition model to predict scale potential up to 250 °C, 1,500 bars, and 6 mol/kg H2O ionic strength. In addition, the mass transfer coefficients were simulated from laminar (Re < 2300) to turbulent (Re > 3,100) flow regimes, as well as the transitional flow regimes (2300 < Re < 3,100) which occur occasionally in the oilfield using sophisticated flow dynamics models. More importantly, the new deposition model also incorporates the impacts of scale inhibitors on scale deposition which was tested and quantified with Langmuir-type kink site adsorption isotherm. The minimum inhibitor dosage required can be predicted at required protection time or maximum deposition thickness rate. This model also includes the impacts of entry-region flow regime in laminar flow, surface roughness, and laminar sublayer stability under turbulent flow. The new mineral scale deposition model was validated by our laminar tubing flow deposition experiments for barite and calcite with or without scale inhibitors and laminar-to-turbulent flow experiments in literature. The good match between experimental result and model predictions show the validity of our new model. This new mineral scale deposition model is the first sophisticated model available in the oil and gas industry that can predict mineral scale deposition in the complex oilfield conditions with and without scale inhibitors. This new mineral scale deposition model will be a useful and practical tool for oilfield scale control.
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Hasslberger, Josef, Peter Katzy, Thomas Sattelmayer, and Lorenz R. Boeck. "Massively Parallelized Simulation of Deflagration-to-Detonation Transition in a Konvoi-Type Pressurized Water Reactor." In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60093.
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For the purpose of nuclear safety analysis, a reactive flow solver has been developed to determine the hazard potential of large-scale hydrogen explosions. Without using empirical transition criteria, the whole combustion process (including DDT) is computed within a single solver framework. In this paper, we present massively parallelized three-dimensional explosion simulations in a full-scale pressurized water reactor of the Konvoi type. Several generic DDT scenarios in globally lean hydrogen-air mixtures are examined to assess the importance of different input parameters. It is demonstrated that the explosion process is highly sensitive to mixture composition, ignition location and thermodynamic initial conditions. Pressure loads on the confining structure show a profoundly dynamic behavior depending on the position in the containment.
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Fukumoto, M., I. Ohgitani, M. Shiiba, and T. Yasui. "Effect of Substrate Surface Change by Heating on Transition in Flattening Behavior of Thermal Sprayed Particles." In ITSC2004, edited by Basil R. Marple and Christian Moreau. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.itsc2004p0246.
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Abstract In the thermal spraying of powder materials, it has been observed in practice that the splat shape changes to a disk type from a splash type with increases in the substrate temperature. However, the details of the substrate surface change due to the heating has not been fully characterized. In this study, an AISI 304 stainless steel substrate surface heated to 673K was analyzed precisely by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy. The results obtained revealed that the change of the substrate surface occurred not in the chemical composition but mainly in the surface roughness, especially surface morphology in nano-meter scale. Hence, substrate heating may bring about the change in substrate surface and this change induces the transition phenomenon.
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Brumovsky, Milan, Radim Kopřiva, and Miloš Kytka. "Embrittlement Trend Curves for Notch and Fracture Toughness of 15Kh2MFAA Type Steel." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65174.
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Reactor pressure vessel integrity and lifetime evaluation is based on the use of fracture mechanics apparatus but most of the material vessel material data and their degradation during operation are based on results from Charpy V-notch impact tests. Then, empirical correlations between transition shift of temperature dependence of notch toughness and fracture toughness are applied. Elaboration of „Master Curve“ approach for fracture toughness experimental data analysis allows to use fracture toughness data directly to the reactor pressure vessel integrity evaluation. Wider use of this approach is limited by the lack of appropriate database from surveillance specimen test data, as mostly only Charpy impact specimen are included into the Surveillance specimen programs. Fortunately, all WWER Surveillance programs contain also fracture toughness specimens, either pre-cracked Charpy size or CT-0.5. Thus, database of fracture toughness data from Surveillance programs of WWER-440/V-213C type reactor pressure vessels, operated in the Czech Republic, Slovakia and Hungary and manufactured only by one manufacturer - SKODA JS, was collated and analyzed. These vessels were manufactured from 15Kh2MFAA type steel and appropriate weld metal, both of Cr-Mo-V type with low content of detrimental impurities — P and Cu. Analysis of the data in fluence interval up to 6×1024 m−2 (with neutron energies En larger than 0.5 MeV) show that transition temperature shifts in fracture toughness temperature dependence are higher than for Charpy impact tests. Several formulae have been applied for fitting these shift dependencies with chemical composition of materials and finally new Embrittlement Trend Curves for Charpy shifts have been corrected. Additionally, new Embrittlement Trend Curves for fracture toughness shifts based on “Master Curve” approach have been also proposed. Both trends are using simple power law on fluence with exponents around 0.6 and depend on phosphorus and copper contents even though effect of other elements has been also checked.
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Kim, Jeong Tae, Byung Hoon Kim, Byeong Ook Kong, and Dong Jin Kim. "Effects of V and Carbides on the Temper Embrittlement of the 2.25Cr-1Mo Steel." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93218.
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The characteristics of temper embrittlement and carbides precipitated in 2.25Cr-1Mo and 2.25Cr-1Mo-V steels which were aged up to 50,000h at 454∼515°C were investigated. The temper embrittlement susceptibility was evaluated as the shift of 54 Joule transition temperature (vTr54) and 50% fracture appearance transition temperature (FATT50) by the Charpy v-notch impact tests. The shift of vTr54 and FATT50 in the 2.25Cr-1Mo steel rapidly increased with the aging time up to 10,000h and then slowly saturated. Peak ΔvTr54 and ΔFATT50 in the 2.25Cr-1Mo-V steel were obtained up to 30,000h aging at 454°C. The distribution of phosphorus in the 2.25Cr-1Mo-V steel and 2.25Cr-1Mo steel after aging treatment was different. Phosphorus in the conventional 2.25Cr-1Mo steel was mainly observed at the prior austenite grain boundary, however, phosphorus in the 2.25Cr-1Mo-V steel was observed at the prior austenite grain boundary and the interfaces between carbide and matrix. The type and composition of carbides were changed to the stable Mo-rich ones, the carbide of M6C type was manifestly precipitated in both steels, and the new type of M4C3 carbides in the 2.25Cr-1Mo-V steel were finely distributed within grain and the atomic ratio of M4C3 was changed from (Fe0.08Cr0.21Mo2.61V1.10)C3 in the PWHT state to (Fe0.22Cr0.20Mo2.78V0.80)C3 with aging.
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Hemmati, Nassim, Sara Borazjani, Abbas Zeinijahromi, Alexander Badalyan, Luis Genolet, Aron Behr, and Pavel Bedrikovetsky. "Determining Relative Permeability and Capillary Pressure from Steady-State-Transient Test Under Formation Damage." In SPE International Conference and Exhibition on Formation Damage Control. SPE, 2022. http://dx.doi.org/10.2118/208826-ms.
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Abstract Previous works develop the method to simultaneously determine relative permeability (Kr) and capillary pressure (Pc) from corefloods – so-called steady-state-transition test (SSTT), which was designed for constant water composition. The SSTT procedure comprises simultaneous injection of water and oil with piecewise-constant increasing injected water fraction until stabilization, measuring pressure drop and effluent water cut during transition periods between the steady-states. In this work, we developed SSTT for high-salinity (HS) and low-salinity (LS) water – HS SSTT is performed in secondary imbibition mode, then the core is fully re-saturated, which follows by LS SSTT in tertiary imbibition mode. To validate SSTT, we performed continuous waterflood by HS and LS after secondary and tertiaty imbibition SSTTs, respectively. The type curves for pressure drop and average saturation are determined by numerical simulation; the raw measured data are approximated by the type curves, yielding regularization of the originally ill-posed inverse problem. The well-posed inverse algorithm produced Kr and Pc curves for HS and LS floods in Berea sandstone. Significant decrease in Kr for water and some decrease in residual oil after LS water injection is explained by mobilization of kaolinite fines by LS water, followed by fines migration and their consequent straining in thin pores: straining of fines causes the permeability decline in the carrier water and sweep improvement at the micro-scale.
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SHAMSHIN, I. O., V. S. IVANOV, V. S. AKSENOV, P. A. GUSEV, and S. M. FROLOV. "EXPERIMENTAL STUDY OF THE INITIAL STAGE OF THE OPERATION PROCESS IN DETONATION ROCKET AND AIR-BREATHING ENGINES." In 13th International Colloquium on Pulsed and Continuous Detonations. TORUS PRESS, 2022. http://dx.doi.org/10.30826/icpcd13a07.
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Detonation propulsion, both rocket-type and air-breathing, is currently a topical direction of research worldwide. Attention is mainly paid to various modes of operation of such engines, their stability, and reliability. As for the issues related to the initiation of the detonation process in such engines, they are usually not considered in detail. However, the initial stage of development of the operation process can be accompanied by a signi¦cant increase in the pressure acting on engine structural elements [1]. In the transition from research to prototypes, issues related to the weight of such engines and their thrust-to-weight ratio will come to the fore. To ensure a minimum margin of safety in engine design, it is required to organize mild rather than strong initiation of operation process excluding the possibility of severe explosions of large volumes of fuel mixture inside the engine or in its close vicinity. This work dealt with experimental simulation of ignition, §ame acceleration, and de§agration-to-detonation transition (DDT) in a semicon¦ned layer of explosive mixture in a slot representing the unrolled annular combustor of a rotating detonation engine. The test mixture was represented by nonpremixed ethylene oxygen mixture of overall stoichiometric composition.
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Al-Yami, Abdullah, Aqeel Shakhouri, Hussain Al-Bahrani, Sara Al-Khalaf, and Vikrant Wagle. "Improved Cement Properties Prevent Well Control Incidents Potentials at Top of Liners." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-21957-ms.
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Abstract Potential well control incidents at Top of Liners (TOL) may take place after cement placement. Typically, liners are run and cemented. After liner hanger is set, reverse circulation takes place. Positive and negative tests might be conducted to ensure integrity at TOL position. Then a clean out run is conducted, and well fluids is displaced to lower fluid density to conduct a flow check after displacement. Potential well control incidents could be indicated from the previous flow tests (positive test, negative test, or flow check test). If potential well control incidents are detected, a proper well control procedure followed by remedial cementing operation will be conducted. The objective of this study is to detail proper cement formulations that is suitable for liner primary cementing, to resist any potentials for possible well control incidents. To mitigate potential well control incidents, cementing practices should be optimized. The cementing practices include cement composition, drilling fluids composition, spacer composition and operations such as pumping procedure and pressure testing. As cement slurry sets, hydrostatic pressure is reduced on the formation. During this transition, gases or fluids can travel up through the cement column resulting in potential kicks. Spacers, cements, and drilling fluids should be designed and tested for compatibility for good displacements and bonding. Different types of spacer are required for each type of drilling fluid, such as salted drilling fluid or oil-based fluids. Testing should include running rheology tests, thickening time tests, and compressive strength development tests. Cement shrinkage is another factor that can lead to potential well control incidents. Expansion additives are usually added to overcome this shrinkage. However, attention should be made to optimize the concentration and type used to avoid over expansion behavior. The study also evaluates the performance of the improved cement formulation against a conventional one. This is achieved by first measuring the relevant mechanical properties of both cement samples using tri-axial loading equipment. The measured properties are then used to populate a numerical model with the required input data. The numerical model is aimed to simulate the performance of each cement formulation within the context of a common and challenging operational scenario that could result in potential wellbore integrity and potential well control incidents.
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Clutter, Keith, Derrick Pease, and George Antaki. "Assessment of Gaseous Detonations in Piping Systems and Pipelines." In ASME 2022 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/pvp2022-84291.
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Abstract This paper covers several practical engineering aspects of gaseous detonations in piping systems: (1) Description of the phenomena and physics of deflagration, detonation, deflagration-to-detonation transition and reflected deflagration-to-detonation transition in piping systems; (2) Development of transient pressures and loads caused by the detonation process in piping systems and in-line components; (3) Analytical evaluation techniques and assessment criteria in the context of the ASME B31 Codes. There are several factors that govern the type and severity of gaseous detonations in piping systems including gas composition, initial pressure and ignition location within the piping system. This paper addresses many of these factors and how they affect the characteristics of gaseous detonations in piping systems. The critical characteristic used to determine the structural integrity of piping systems to withstand a detonation is the transient pressure history inside the piping. This paper addresses how to develop such transient pressure histories that can then be readily applied to analytical structural models. There are several methods that can be used to apply a transient pressure history to a structural model of a piping system. This paper addresses some methods that have been used to apply this type of loading to finite element models in Abaqus. These methods could be easily adapted to other FEA software packages. There are also several evaluation methods that can be used to determine the structural integrity of the piping system. This paper addresses some of the more advance methods involving plastic deformation with strain limit damage and explicit time-history solvers. Finally, this paper is specifically focused on piping systems and pipelines where gaseous detonations have unique characteristics compared to more open volumes such as tanks and vessels. A separate paper (PVP2022-84269) addresses the unique characteristics of gaseous detonations in pressure vessels.
Reports on the topic "Transitional to OIB-type compositions"
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Leis, Sherry. Vegetation community monitoring at Lincoln Boyhood National Memorial: 2011–2019. National Park Service, April 2021. http://dx.doi.org/10.36967/nrr-2284711.
Full textAbstract:
Lincoln Boyhood National Memorial celebrates the lives of the Lincoln family including the final resting place of Abraham’s mother, Nancy Hanks Lincoln. Lincoln’s childhood in Indiana was a formative time in the life our 16th president. When the Lincoln family arrived in Indiana, the property was covered in the oak-hickory forest type. They cleared land to create their homestead and farm. Later, designers of the memorial felt that it was important to restore woodlands to the site. The woodlands would help visitors visualize the challenges the Lincoln family faced in establishing and maintaining their homestead. Some stands of woodland may have remained, but significant restoration efforts included extensive tree planting. The Heartland Inventory and Monitoring Network began monitoring the woodland in 2011 with repeat visits every four years. These monitoring efforts provide a window into the composition and structure of the wood-lands. We measure both overstory trees and the ground flora within four permanently located plots. At these permanent plots, we record each species, foliar cover estimates of ground flora, diameter at breast height of midstory and overstory trees, and tree regeneration frequency (tree seedlings and saplings). The forest species composition was relatively consistent over the three monitoring events. Climatic conditions measured by the Palmer Drought Severity Index indicated mild to wet conditions over the monitoring record. Canopy closure continued to indicate a forest structure with a closed canopy. Large trees (>45 cm DBH) comprised the greatest amount of tree basal area. Sugar maple was observed to have the greatest basal area and density of the 23 tree species observed. The oaks characteristic of the early woodlands were present, but less dominant. Although one hickory species was present, it was in very low abundance. Of the 17 tree species recorded in the regeneration layer, three species were most abundant through time: sugar maple (Acer saccharum), red bud (Cercis canadensis), and ash (Fraxinus sp.). Ash recruitment seemed to increase over prior years and maple saplings transitioned to larger size classes. Ground flora diversity was similar through time, but alpha and gamma diversity were slightly greater in 2019. Percent cover by plant guild varied through time with native woody plants and forbs having the greatest abundance. Nonnative plants were also an important part of the ground flora composition. Common periwinkle (Vinca minor) and Japanese honeysuckle (Lonicera japonica) continued to be the most abundant nonnative species, but these two species were less abundant in 2019 than 2011. Unvegetated ground cover was high (mean = 95%) and increased by 17% since 2011. Bare ground increased from less than 1% in 2011 to 9% in 2019, but other ground cover elements were similar to prior years. In 2019, we quantified observer error by double sampling two plots within three of the monitoring sites. We found total pseudoturnover to be about 29% (i.e., 29% of the species records differed between observers due to observer error). This 29% pseudoturnover rate was almost 50% greater than our goal of 20% pseudoturnover. The majority of the error was attributed to observers overlooking species. Plot frame relocation error likely contributed as well but we were unable to separate it from overlooking error with our design.
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Short, Mary, and Sherry Leis. Vegetation monitoring in the Manley Woods unit at Wilson’s Creek National Battlefield: 1998–2020. Edited by Tani Hubbard. National Park Service, June 2022. http://dx.doi.org/10.36967/nrr-2293615.
Full textAbstract:
Natural resource management at Wilson’s Creek National Battlefield (NB) is guided by our understanding of the woodlands and prairies at the time of the Civil War battle in 1861. This report is focused on the Manley Woods unit of the park. This unit is an oak-hickory woodland in the Springfield Plain subsection of the Ozarks. Canopy closure for Missouri oak woodlands can be highly variable and ranges from 30–100% across the spectrum of savanna, open woodland, and closed woodland types. In 1861, the woodland was likely a savanna community. Changes in land use (e.g., fire exclusion) caused an increase in tree density in woodlands at Wilson’s Creek NB and across the Ozarks. Savannas and open woodlands transitioned to closed canopy woodlands over time. Park management plans include restoring the area to a savanna/open woodland structure. Prescribed fire was reintroduced to Wilson’s Creek NB in 1988 and continues as the primary mechanism for reducing the tree canopy. The Manley Woods unit of Wilson’s Creek NB has been subject to intense natural and anthropogenic disturbance events such as a tornado in 2003, timber removal in 2005, prescribed fires in 2006, 2009, and 2019, an ice storm in 2007, and periodic drought. The Heartland Inventory and Monitoring Network (hereafter, Heartland Network) installed four permanent monitoring sites within the Manley Woods area of the park in 1997. Initially, we assessed ground flora and regeneration within the sites (1998–1999). We added fuel sampling after the 2003 tornado. Although overstory sampling occurred prior to the tornado, the protocol was not yet stabilized and pre-2003 overstory data were not included in these analyses. In this report, we focus on the overstory, tree regeneration, and ground cover metrics; ground flora data will be assessed in future analyses. Heartland Network monitoring data reveal that Manley Woods has undergone substantial change in canopy cover and midstory trees since 1998. While basal area and density metrics classify Manley Woods as an open woodland, the closed canopy of the midstory and overstory reveal a plant community that is moving toward closed woodland or forest structure. The most recent fire in 2019 was patchy and mild, resulting in continued increases in fuels. Ground cover metrics indicate infrequent disturbance since leaf litter continued to increase. Management objectives to restore savanna or woodland composition and structure to the Manley Woods overstory, regeneration layer, and ground cover will require implementation of prescribed fire in the future. Repeated fires can thin midstory trees and limit less fire tolerant early seral species. Additionally, mechanical or chemical treatments to reduce undesirable tree species should be considered for woodland restoration. Decreasing canopy closure is an important and essential step toward the restoration of a functioning savanna/open woodland plant community in Manley Woods. Treatments that thin the midstory and reduce fuel loading will also benefit these plant communities. With the anticipated changing climate, maintaining an open woodland community type may also provide resilience through management for native species tolerant of increasingly warmer temperatures.
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Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.
Full textAbstract:
The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.