Search results for "Oxygen diffusion"

showing 7 items of 7 documents

First principles calculations of oxygen vacancy formation and migration in mixed conducting Ba0.5Sr0.5Co1−yFeyO3−δ perovskites

2011

Abstract First-principles supercell calculations of oxygen vacancies in the Ba 0.5 Sr 0.5 Co 1− y Fe y O 3− δ (BSCF) perovskites are presented. The density of states is determined for different iron content and oxygen vacancy concentrations, and the characteristic differences for Co and Fe are discussed. We analyze the dependences of the defect (oxygen vacancy) formation and migration energies on the Fe content and compare the calculated properties with those of related LaCoO 3 and LaFeO 3 perovskites.

Materials scienceInorganic chemistrychemistry.chemical_elementFe content02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesOxygenOxygen vacancy0104 chemical scienceschemistryIron contentDensity of statesSupercell (crystal)Oxygen diffusionIonic conductivityPhysical chemistryGeneral Materials Science0210 nano-technologySolid State Ionics
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Respiratory Gas Transport in Heart

1973

The purpose of this paper is to describe an attempt to obtain a better understanding of the dynamics of the oxygen supply of the myocardium under physiological and pathophysiological conditions by examining the oxygen diffusion in the heart muscle tissue during systole and diastole. In comparison to other organs the oxygen supply of the myocardium is characterized by a number of specific features. The most important one is that the gas exchange in the myocardium is a nonsteady-state diffusion process.

Muscle tissueOxygen supplymedicine.anatomical_structureCardiac cycleChemistrycardiovascular systemmedicineBiophysicsDiastoleOxygen diffusionRespiratory gas transportOxygen tension
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Oxygen Diffusion Constants D and K of Tumor Tissue (DS-Carcinosarcoma) and Their Temperature Dependence

1978

To understand more thoroughly the tumor O2 supply conditions, knowledge of O2 diffusivity in tumor tissue is required. Since exact measurements of the O2 diffusion constants of tumor tissue have not been carried out to date, previous investigations of tumor O2 supply had to employ estimated values (6 – 8, 10). The results of these studies are in part contradictory.

Nuclear magnetic resonanceChemistryCarcinosarcomamedicineOxygen diffusionTissue necrosisDiffusion (business)medicine.diseaseThermal diffusivityTumor tissueFick's laws of diffusion
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Oxygen diffusion in tissues supplied by capillaries.

1968

(1968). Oxygen Diffusion in Tissues Supplied by Capillaries. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 21, No. sup102, pp. II-B-II-B.

OxygenChemistryPartial PressureClinical BiochemistryRadiochemistryOxygen diffusionGeneral MedicineModels BiologicalBlood Flow VelocityCapillariesScandinavian journal of clinical and laboratory investigation. Supplementum
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Oxygen Diffusion in Alumina. Application to Synthetic and Thermally Grown Al<sub>2</sub>O<sub>3</sub>

2005

S. Chevalier, B. Lesage, C. Legros, G. Borchardt, G. Strehl, M. Kilo Laboratoire de Recherches sur la Reactivite des Solides, CNRS UMR 5613, Universite de Bourgogne, F-21078 Dijon, France Laboratoire d’Etudes des Materiaux Hors Equilibre, CNRS UMR 8647, Universite Paris XI, F-91405 Orsay, France. Institut fur Metallurgie, TU Clausthal, Robert Koch Strasse 42, D38678 Clausthal-Zellerfeld, Germany. * sebastien.chevalier@u-bourgogne.fr

RadiationMaterials scienceMetallurgyOxygen diffusionGeneral Materials ScienceCondensed Matter PhysicsDefect and Diffusion Forum
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Micromechanical approach of the high temperature oxidation of zirconium: study of the Zr/ZrO2 interfacial epitaxy with Bollmann's method

1997

The method of Bollmann has been used to determine the role of epitaxy in the formation of the mechanical stress field near the metal/oxide interface during the high temperature oxidation of zirconium. The strains due to epitaxy combine with those due to both oxygen diffusion in metal and thermal expansion of the metal/oxide composite in a model based on a micromechanical formalism. The calculated values are compared to experimental results and the applicability of Bollmann's method to this problem is discussed.

ZirconiumChemistryOxidechemistry.chemical_elementMineralogyGeneral ChemistryOxide compositeCondensed Matter PhysicsEpitaxyThermal expansionMetalchemistry.chemical_compoundTransition metalvisual_artvisual_art.visual_art_mediumOxygen diffusionGeneral Materials ScienceComposite materialSolid State Ionics
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Germination Pattern of Chamaerops humilis Seed after Short-Time Storage

2015

Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted…

seed ageingved/biologyved/biology.organism_classification_rank.speciesfood and beveragesSowinggermination timing patternSettore AGR/04 - Orticoltura E FloricolturaHorticultureBiologygermination ratebiology.organism_classificationMediterranean vegetationShrubHorticulturechemistry.chemical_compoundChamaeropschemistrydwarf fan palmGerminationSeed treatmentOxygen diffusionPalm
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