Search results for "Fugacity"

showing 8 items of 38 documents

Seawater carbonate chemistry and coralline algal diversity

2021

Calcified coralline algae are ecologically important in rocky habitats in the marine photic zone worldwide and there is growing concern that ocean acidification will severely impact them. Laboratory studies of these algae in simulated ocean acidification conditions have revealed wide variability in growth, photosynthesis and calcification responses, making it difficult to assess their future biodiversity, abundance and contribution to ecosystem function. Here, we apply molecular systematic tools to assess the impact of natural gradients in seawater carbonate chemistry on the biodiversity of coralline algae in the Mediterranean and the NW Pacific, link this to their evolutionary history and …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityCommunity composition and diversityBicarbonate ion standard deviationinorganicAlkalinity total standard deviationAlkalinityExperimentTemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010Aragonite saturation stateNorth PacificMarine habitatAlkalinity totaltotalCO2 ventpHTemperaturedissolvedCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Calcium carbonate standard deviationstandard errorEarth System Researchstandard deviationField observationCalcium carbonateCoverageCalcite saturation stateLocationwaterPartial pressure of carbon dioxideSiteRocky-shore communityCalcium carbonate massAragonite saturation state standard deviationBenthosSalinity standard deviationOcean Acidification International Coordination Centre OA ICCMediterranean SeaCarbon inorganic dissolved standard deviationCalcite saturation state standard deviationTypeBicarbonate ionCalculated using seacarb after Nisumaa et al. (2010)Coverage standard errorfungiEvent labelPartial pressure of carbon dioxide standard deviationCarbonate system computation flagpH standard deviationCarbonate ion standard deviationFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonPartial pressure of carbon dioxide water at sea surface temperature wet airCarbon dioxideRocky shore communityEntire communityFugacity of carbon dioxide water at sea surface temperature wet airCoast and continental shelfSpecies richness
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Decline in Coccolithophore Diversity and Impact on Coccolith Morphogenesis Along a Natural CO2 Gradient

2014

A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityCommunity composition and diversityinorganicAlkalinityCoccospheres malformedMediterranean Sea Acidification in a Changing Climate MedSeATemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010Aragonite saturation stateAlkalinity totaltotalCO2 ventpHPelagosTemperaturedissolvedCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Earth System ResearchmalformedField observationPotentiometric titrationCalcite saturation stateCoccospheresPotentiometricwaterGrowth MorphologyMediterranean Sea Acidification in a Changing Climate (MedSeA)Ocean Acidification International Coordination Centre OA ICCMediterranean SeaBicarbonate ionCalculated using seacarb after Nisumaa et al. (2010)Calculated using CO2SYSfungiCarbonate system computation flagCoccospheres corrodedFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonBiomass/Abundance/Elemental compositionPartial pressure of carbon dioxide water at sea surface temperature wet airSample IDCarbon dioxidecorrodedEntire communityGrowth/MorphologyPhytoplanktonFugacity of carbon dioxide water at sea surface temperature wet airBiomass Abundance Elemental compositionCoast and continental shelfNumber of species
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Shallow water marine sediment bacterial community shifts along a natural CO2 gradient in the Mediterranean Sea Off vulcano, Italy

2014

The effects of increasing atmospheric CO(2) on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO(2) gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 µatm, minimum Omega (arag) 3.77), moderately CO(2)-enriched (median pCO(2) 592 µatm, minimum Omega (arag) 2.96), and highly CO(2)-enriched (median pCO(2) 1611…

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityPotentiometric titrationCalcite saturation stateCommunity composition and diversityPotentiometricinorganicwaterAlkalinitySiteFigureBenthosTemperature waterCarbon inorganic dissolvedAbundanceCalculated using seacarb after Nisumaa et al 2010Ocean Acidification International Coordination Centre OA ICCMediterranean SeaBicarbonate ionAragonite saturation stateSoft-bottom communityAlkalinity totalLONGITUDEtotalCalculated using seacarb after Nisumaa et al. (2010)CO2 ventSpeciesShannon Diversity IndexpHCalculated using CO2SYSTemperatureCarbonate system computation flagdissolvedFugacity of carbon dioxide (water) at sea surface temperature (wet air)Carbonate ionCarbonPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Partial pressure of carbon dioxide water at sea surface temperature wet airCarbon dioxideSoft bottom communityEntire communityEarth System ResearchLATITUDEFugacity of carbon dioxide water at sea surface temperature wet airGroupCoast and continental shelfField observationClass
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Phase Transitions in Multicomponent Widom-Rowlinson Models

1995

We use Monte Carlo techniques to study the phase diagram of multicomponent Widom-Rowlinson models on a square lattice: there are M species all with the same fugacity z and a nearest neighbor hard core exclusion between unlike particles. For M between two and six there is a direct transition from the gas phase at z z d (M). For M ≥ 7 there is an intermediate ordered phase in which the even (or odd) sublattice is occupied preferentially by particles chosen at random from any of the species. The existence of such an intermediate phase was proven earlier for M ≥ M 0, M 0 very large. Exact calculations on the Bethe lattice give M0 = 4.

PhysicsPhase transitionCondensed matter physicsBethe latticePhase (matter)Monte Carlo methodFugacitySquare latticek-nearest neighbors algorithmPhase diagram
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Elastic moduli, dislocation core energy and melting of hard disks in two dimensions

2000

Elastic moduli and dislocation core energy of the triangular solid of hard disks of diameter $\sigma$ are obtained in the limit of vanishing dislocation- antidislocation pair density, from Monte Carlo simulations which incorporates a constraint, namely that all moves altering the local connectivity away from that of the ideal triangular lattice are rejected. In this limit, we show that the solid is stable against all other fluctuations at least upto densities as low as $\rho \sigma^2 = 0.88$. Our system does not show any phase transition so diverging correlation lengths leading to finite size effects and slow relaxations do not exist. The dislocation pair formation probability is estimated …

PhysicsPhase transitionCondensed matter physicsStatistical Mechanics (cond-mat.stat-mech)Monte Carlo methodFOS: Physical sciencesHexagonal latticeFugacityLimit (mathematics)DislocationHexatic phaseElastic modulusCondensed Matter - Statistical Mechanics
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Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2 gradient

2016

Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (400 µatm) and high (800-1000 µatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that sp…

StageOcean Acidification International Coordination Centre (OA-ICC)TemperateRegistration number of speciesSalinityinorganicYolk area standard errorAlkalinityExperimentTemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010Aragonite saturation stateRespiration rate oxygenChordataAlkalinity totaltotalCO2 ventpHPelagosReproductionRespirationSymphodus ocellatusTemperatureYolk areadissolvedCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Field experimentTemperature water standard deviationTime pointstandard errorRespiration rateEarth System Researchstandard deviationFOS: Medical biotechnologyUniform resource locator link to referenceTime point descriptiveHatchling lengthCalcite saturation statewaterPartial pressure of carbon dioxidedescriptiveGrowth MorphologyFigureUniform resource locator/link to referenceSalinity standard deviationOcean Acidification International Coordination Centre OA ICCMediterranean SeaAnimaliaEggs areaTypeBicarbonate ionNektonEggs area standard errorCalculated using seacarb after Nisumaa et al. (2010)SpeciesPartial pressure of carbon dioxide standard deviationCarbonate system computation flagpH standard deviationHatchling length standard errorFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonTreatmentOxygenPartial pressure of carbon dioxide water at sea surface temperature wet airCarbon dioxideGrowth/MorphologySingle speciesOxygen standard deviationFugacity of carbon dioxide water at sea surface temperature wet airCoast and continental shelf
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Phase Transitions in the Multicomponent Widom-Rowlinson Model and in Hard Cubes on the BCC--Lattice

1997

We use Monte Carlo techniques and analytical methods to study the phase diagram of the M--component Widom-Rowlinson model on the bcc-lattice: there are M species all with the same fugacity z and a nearest neighbor hard core exclusion between unlike particles. Simulations show that for M greater or equal 3 there is a ``crystal phase'' for z lying between z_c(M) and z_d(M) while for z > z_d(M) there are M demixed phases each consisting mostly of one species. For M=2 there is a direct second order transition from the gas phase to the demixed phase while for M greater or equal 3 the transition at z_d(M) appears to be first order putting it in the Potts model universality class. For M large, …

Statistics and ProbabilityPhysicsPhase transitionCondensed matter physicsStatistical Mechanics (cond-mat.stat-mech)FOS: Physical sciencesRenormalization groupCondensed Matter Physicsk-nearest neighbors algorithmLattice (order)Ising modelFugacityCondensed Matter - Statistical MechanicsPhase diagramPotts model
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Temperature, fluid content and rheology of localized ductile shear zones in subsolidus cooling plutons

2020

Temperature and fluid content are critical parameters that control rock rheology and strain localization in the continental crust. Here, we determine by thermodynamic modelling the urn:x-wiley:02634929:media:jmg12553:jmg12553-math-0004 of localized ductile shearing during cooling of three different granitoid plutons: the Rieserferner and the Adamello plutons in the Italian Alps, and the Lake Edison pluton in the Sierra Nevada—USA. Shear zones exploited precursor joints, associated veins and alteration zones. urn:x-wiley:02634929:media:jmg12553:jmg12553-math-0005 and P−T phase diagram sections were computed with Perple_X in the system MnO−Na2O−CaO −K2O−FeO−MgO−Al2O3−SiO2−H2O−Fe2O3. The phase…

cooling pluton; localized shear zone; rheology; temperature; water fugacitywater fugacity010504 meteorology & atmospheric sciencesPluton[SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/PetrographytemperatureGeologylocalized shear zone010502 geochemistry & geophysics01 natural sciencescooling plutonRheology13. Climate actionGeochemistry and Petrologycooling pluton localized shear zone rheology temperature water fugacityrheologyShear zonePetrologyComputingMilieux_MISCELLANEOUSGeology0105 earth and related environmental sciencesJournal of Metamorphic Geology
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