Search results for "Oxygen starvation"

showing 3 items of 3 documents

Chlorophyll fluorescence, photosynthesis and growth of tomato plants as affected by long-term oxygen root zone deprivation and grafting

2020

A greenhouse experiment was conducted to study the effects of the O2 root zone level and grafting on chlorophyll fluorescence, photosynthesis and growth of cherry tomato grown in a hydroponic system. Two O2 concentrations in the root zone, namely Ox (saturation level) and Ox- (2&ndash

0106 biological sciencesStomatal conductancechlorophyll fluorescence; oxygen starvation; photosynthesis; rootstock; stomatal conductance; tomatoRoot systemSettore AGR/04 - Orticoltura E FloricolturatomatoPhotosynthesis01 natural scienceslcsh:AgricultureCherry tomatophotosynthesiChlorophyll fluorescenceTranspirationphotosynthesisbiologychlorophyll fluorescenceChemistrylcsh:Sfood and beverages04 agricultural and veterinary sciencesrootstockbiology.organism_classificationoxygen starvationHorticulturestomatal conductance040103 agronomy & agriculture0401 agriculture forestry and fisheriesDNS root zoneRootstockAgronomy and Crop Science010606 plant biology & botany
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PEM Fuel Cell System Model Predictive Control and real-time operation on a power emulator

2010

Fuel Cell Systems (FCS) seem to be among the most reliable devices to produce clean energy, although they still suffer for many problems, mostly related to the fragility of the Polymer Electrolyte Membrane (PEM). Particularly, this paper focuses on the oxygen starvation, that leads both a decrease of the FCS performance and a shortening in the FCS lifetime. The purpose is to use the Model Predictive Control (MPC) and its capacity of accounting for linear constraints for managing the air system without risking to damage the fuel cell. Two control inputs and no static feed-forward actions have been used. Results show that the MPC is able to avoid the oxygen starvation, even with a sudden incr…

Engineeringair managementmodel predictive controlbusiness.industryProton exchange membrane fuel cellConvertersfuel cell systemsSystem modelPower (physics)Model predictive controlFragilityControl theoryFuel cellslipids (amino acids peptides and proteins)businessOxygen starvation2010 IEEE Energy Conversion Congress and Exposition
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Improvement of the mechanical properties of photo-oxidized films after recycling

2002

Mechanical recycling of post-consumer plastics gives rise, in most cases, to secondary materials with mechanical properties worse than those of the reclaimed polymer. This is mostly due to the thermomechanical treatment undergone during the melt reprocessing operations. In this work, low density polyethylene films have been photo-oxidized in artificial accelerated ageing conditions and then the brittle films have been melt reprocessed. It is shown that the secondary material, after reprocessing, shows mechanical properties, in particular elongation at break, better than those of the photo-oxidized films. This behaviour has been attributed to the fact that the melt reprocessing has the effec…

chemistry.chemical_classificationMaterials sciencePolymers and PlasticsOxidative degradationPolymerCondensed Matter PhysicsMolten stateLow-density polyethyleneBrittlenesschemistryMechanics of MaterialsMaterials ChemistryPhotochemical degradationComposite materialElongationOxygen starvationPolymer Degradation and Stability
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