Search results for "alkali"

showing 10 items of 566 documents

A rapid separation of the four major deoxynucleosides and deoxyinosine by high-pressure liquid cation-exchange chromatography

1973

DeoxyribonucleasesChromatographyIon exchangePhosphoric Diester HydrolasesVenomsChemistryDeoxyribonucleotidesIon chromatographyBiophysicsPhosphoric Diester HydrolasesDeoxyribonucleosidesDNACell BiologyAlkaline PhosphataseChromatography Ion ExchangeBiochemistryMicrococcusHigh pressureMethodsPressureMolecular BiologyNucleic acid analogueAnalytical Biochemistry
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Active alkaline traps to determine acidic-gas ratios in volcanic plumes: Sampling techniques and analytical methods

2014

In situ measurements have been the basis for monitoring volcanic gas emissions for many years and—being complemented by remote sensing techniques—still play an important role to date. Con- cerning in situ techniques for sampling a dilute plume, an increase in accuracy and a reduction of detection limits are still necessary for most gases (e.g., CO2, SO2, HCl, HF, HBr, HI). In this work, the Raschig-Tube tech- nique (RT) is modified and utilized for application on volcanic plumes. The theoretical and experimental absorption properties of the RT and the Drechsel bottle (DB) setups are characterized and both are applied simultaneously to the well-established Filter packs technique (FP) in the …

Detection limitgeographyAnalytegeography.geographical_feature_categoryalkaline traps plume sampling sulfur and halogen Etna volcanoDifferential optical absorption spectroscopyIon chromatographyMineralogySettore GEO/08 - Geochimica E VulcanologiaPlumeGeophysicsVolcanoGeochemistry and PetrologyAbsorption (electromagnetic radiation)Inductively coupled plasma mass spectrometryGeologyGeochemistry, Geophysics, Geosystems
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A snapshot of the transition from monogenetic volcanoes to composite volcanoes: Case study on the Wulanhada Volcanic Field (northern China)

2022

The transition processes from monogenetic volcanoes to composite volcanoes are poorly understood. The Late Pleistocene to Holocene intraplate monogenetic Wulanhada Volcanic Field (WVF) in northern China provides a snapshot of such a transition. Here we present petrographic observations, mineral chemistry, bulk rock major and trace element data, thermobarometry, and a partial melting model for the WVF to evaluate the lithology and partial melting degree of the mantle source, the crystallization conditions, and pre-eruptive magmatic processes occurring within the magma plumbing system. The far-field effect of India–Eurasia collision resulted in a relatively high degree (10 %–20 %) of partial …

Dewey Decimal Classification::500 | Naturwissenschaften::550 | GeowissenschaftenDewey Decimal Classification::500 | Naturwissenschaften::540 | ChemieMagnesiaLithologyFeldsparddc:540ddc:550AlkalinityMelting
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Phase diagram of calcium at high pressure and high temperature

2018

Resistively heated diamond-anvil cells have been used together with synchrotron x-ray diffraction to investigate the phase diagram of calcium up to 50 GPa and 800 K. The phase boundaries between the Ca-I (fcc), Ca-II (bcc), and Ca-III (simple cubic, sc) phases have been determined at these pressure-temperature conditions, and the ambient temperature equation of state has been generated. The equation of state parameters at ambient temperature have been determined from the experimental compression curve of the observed phases by using third-order Birch-Murnaghan and Vinet equations. A thermal equation of state was also determined for Ca-I and Ca-II by combining the room-temperature Birch-Murn…

DiffractionEquation of stateMaterials sciencePhysics and Astronomy (miscellaneous)Thermodynamics02 engineering and technologyCubic crystal system01 natural sciencesThermal expansionPhysics::GeophysicsSynchrotronCondensed Matter::Materials SciencePhase (matter)0103 physical sciencesGeneral Materials Science010306 general physicsPhase diagramAlkaline earth metalTransitionsEquation-of-state021001 nanoscience & nanotechnologyX-ray crystallographyX-Ray-diffractionAlkaline-earth metals0210 nano-technology
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Calcification is not the Achilles'heel of cold-water corals in an acidifying ocean

2015

Ocean acidification is thought to be a major threat to coral reefs: laboratory evidence and CO2 seep research has shown adverse effects on many coral species, although a few are resilient. There are concerns that cold-water corals are even more vulnerable as they live in areas where aragonite saturation (Omega ara) is lower than in the tropics and is falling rapidly due to CO2 emissions. Here, we provide laboratory evidence that net (gross calcification minus dissolution) and gross calcification rates of three common cold-water corals, Caryophyllia smithii, Dendrophyllia cornigera, and Desmophyllum dianthus, are not affected by pCO2 levels expected for 2100 (pCO2 1058 µatm, Omega ara 1.29),…

Dissolution rateOcean Acidification International Coordination Centre (OA-ICC)TemperateIdentificationSalinityBicarbonate ion standard deviationinorganicAlkalinity total standard deviationAlkalinityExperimentTemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010Aragonite saturation stateRespiration rate oxygenAlkalinity totaltotalDesmophyllum dianthuspHRespirationTemperatureCalcification rate of calcium carbonatedissolvedLaboratory experimentCarbonate ionDeep seaPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Field experimentCarbon dioxide standard deviationTemperature water standard deviationContainers and aquaria 20 1000 L or 1 m 2Respiration rateEarth System ResearchContainers and aquaria (20-1000 L or &lt; 1 m**2)standard deviationCalcification/DissolutionPotentiometric titrationCalcite saturation statePotentiometricwaterPartial pressure of carbon dioxideCaryophyllia smithiiContainers and aquaria (20-1000 L or < 1 m**2)Dendrophyllia cornigeraFigureAragonite saturation state standard deviationBenthosCnidariaOcean Acidification International Coordination Centre OA ICCMediterranean SeaAnimaliaBicarbonate ionCalculated using seacarb after Nisumaa et al. (2010)SpeciesCalculated using CO2SYSfungiEvent labelDeep-seaPartial pressure of carbon dioxide standard deviationCarbonate system computation flagpH standard deviationCarbonate ion standard deviationbiochemical phenomena metabolism and nutritionFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonTreatmentPartial pressure of carbon dioxide water at sea surface temperature wet airCarbon dioxideSingle speciesCalcification DissolutionFugacity of carbon dioxide water at sea surface temperature wet airBenthic animalsoxygen
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Energy transfer from colour centres to the dopant in alkali halides

1997

Abstract Energy transfer from F centres to the dopant ions in photostimulated processes is examined. It was found that in alkali halide systems the radiation defects are disposed in near vicinity of the dopants. Recombination of defects also takes place to a limited extent near the dopant with a fast and high-yield energy transfer to the latter. Role of unrelaxed H centres in the formation of donor-acceptor pairs is discussed. Some special exciton energy transfer mechanisms are analysed as well.

DopantPhotostimulated luminescenceChemistryExcitonInorganic chemistryBiophysicsHalideGeneral ChemistryRadiationCondensed Matter PhysicsAlkali metalPhotochemistryBiochemistryAtomic and Molecular Physics and OpticsIonRecombinationJournal of Luminescence
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The Magmatic to Hydrothermal Evolution of the Intrusive Mont Saint-Hilaire Complex: Insights into the Late-stage Evolution of Peralkaline Rocks

2017

The Cretaceous Mont Saint-Hilaire complex (Quebec, Canada) comprises three major rock units that were emplaced in the following sequence: (I) gabbros; (II) diorites; (III) diverse partly agpaitic foid syenites. The major element compositions of the rock-forming minerals, age-corrected Nd and oxygen isotope data for mineral separates and trace element data of Fe-Mg silicates from the various lithologies imply a common source for all units. The distribution of the rare earth elements in clinopyroxene from the gabbros indicates an ocean island basalt type composition for the parental magma. Gabbros record temperatures of 1200 to 800 degrees C, variable silica activities between 0 center dot 7 …

Earth scienceTrace elementGeochemistryOcean island basaltPeralkaline rockIsotopes of oxygenSilicateHydrothermal circulationchemistry.chemical_compoundGeophysicschemistryGeochemistry and PetrologyCarbonateFluid inclusionsGeology
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Ocean acidification affects fish spawning but not paternity at CO2 seeps

2016

Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse (Symphodus ocellatus) compete to fertilize eggs guarded by dominant nesting males. Key mating behaviours such as dominant male courtship and nest defence did not differ between sites with ambient versus elevated CO2 concentrations. Dominant males did, however, experience significantly lower rates of pair spawning at elevated CO2 levels. Despite the higher r…

Eggs standard errorOcean Acidification International Coordination Centre (OA-ICC)TemperateRegistration number of speciesIdentificationSalinityEggsinorganicAlkalinityExperimentNumber standard errorDominant male paternityTemperature waterCarbon inorganic dissolvedNumber of individualsCalculated using seacarb after Nisumaa et al 2010Number of spawning events standard errorAragonite saturation stateFish standard lengthChordataAlkalinity totalSalinity standard errortotalCO2 ventReplicatesCourtship standard errorpHPelagosReproductionSymphodus ocellatusTemperatureNumberPartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)standard errorIndividuals standard errorEarth System ResearchField observationFOS: Medical biotechnologyUniform resource locator link to referencePotentiometric titrationCalcite saturation stateLocationPotentiometricwaterNumber of spawning eventsAgeUniform resource locator/link to referenceOcean Acidification International Coordination Centre OA ICCMediterranean SeaAnimaliaEggs areaBehaviourTypeBicarbonate ionNektonEggs area standard errorTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)SpeciespH standard errorWet massDominant male paternity standard errorCalculated using CO2SYSEvent labelIndividualsCourtshipCarbonate system computation flagstandard lengthFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonTreatmentPartial pressure of carbon dioxide water at sea surface temperature wet airFishCarbon dioxideSingle speciesFugacity of carbon dioxide water at sea surface temperature wet airCoast and continental shelf
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Hydrogen from The Sea: The Challenge of the Future. Present and Future Developments

2014

In this paper we proposed the use of saline water to product hydrogen. As far as using saline water, can be proposed two different scheme and technology. The aim of this work is to design an electrolyze system capable of utilizing sea water for direct electrolysis. It is probable that these systems would operate at a low power density and electrolyze only a small portion of the water in contact with electrodes. In particular, we present the results obtained by two different prototype of electrolyzer: one with steel electrodes and the second electrodes with titanium. Further experiments were carried out by changing the electrolytic solution of water and sodium chloride in real seawater. Fina…

ElectrolysisSettore ING-IND/11 - Fisica Tecnica AmbientaleElectrical loadElectrolysis of waterbusiness.industryMetallurgyHigh-pressure electrolysisAlkaline water electrolysisSettore ING-IND/32 - Convertitori Macchine E Azionamenti Elettricilaw.inventionlawEnvironmental scienceWater splittingSeawaterProcess engineeringbusinessPolymer electrolyte membrane electrolysisSea water electrolysis hydrogen new fuel
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Analysis of self-trapped hole mobility in alkali halides and metal halides

2017

Support from Latvian National Research Program IMIS2 (2014–2017) and LZP Grant No. 237/2012 (2013–2016) is greatly appreciated.

Electron mobilityChemistryInorganic chemistryHalide02 engineering and technologyGeneral ChemistryElectron021001 nanoscience & nanotechnologyCondensed Matter PhysicsPolaronAlkali metal01 natural scienceschemistry.chemical_compoundMetal halidesChemical physicsLattice (order)0103 physical sciences:NATURAL SCIENCES:Physics [Research Subject Categories]General Materials ScienceRadiation stability010306 general physics0210 nano-technologySolid State Ionics
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