Search results for "Gradation"

showing 10 items of 1275 documents

Photocatalytic membrane reactors: fundamentals, membrane materials and operational issues

2013

Abstract: This chapter reports the properties of semiconductor materials used in heterogeneous photocatalysis together with a comparison of heterogeneous photocatalytic systems and a brief description of the types of membranes that can be used. Some aspects of membrane operations, such as fouling, separation of a photocatalyst and effectiveness of photodegradation on permeate quality are discussed.

Settore ING-IND/24 - Principi Di Ingegneria ChimicaMembraneMaterials scienceWaste managementMembrane reactorFoulingSemiconductor materialsHeterogeneous photocatalysis membranes photocatalytic membrane reactorsPhotocatalysisNanotechnologyPermeationPhotodegradation
researchProduct

Photocatalytic degradation of 4-nitrophenol in a continuous reactor containing titanium dioxide supported on glass beads

2008

WOS: 000258975200009

Settore ING-IND/24 - Principi Di Ingegneria ChimicaTitanium DioxideMaterials scienceContinuous reactor4-NitrophenolElectrochemistryContinuous PhotoreactorCatalysischemistry.chemical_compoundchemistryChemical engineering4-NitrophenolTitanium dioxideOxidationPhotocatalysis4-Nitrophenol Photocatalysis Oxidation Titanium dioxide Continuous photoreactorPhysical and Theoretical ChemistryPhotocatalysisPhotocatalytic degradationSelf-cleaning glass
researchProduct

Coexistence between IEEE802.15.4 and IEEE802.11 through cross-technology signaling

2017

When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and requiring technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, this paper proposes an architecture that allows crosstechnology medium access by means of a Time Division Multiple Access (TDMA) scheme. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon…

Settore ING-INF/03 - TelecomunicazioniComputer sciencebusiness.industryDistributed computingComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSTestbedTime division multiple access020206 networking & telecommunications02 engineering and technologyInterference (wave propagation)Radio spectrumSynchronization (computer science)0202 electrical engineering electronic engineering information engineeringWirelessIBCN020201 artificial intelligence & image processingMAC protocols interference mitigation crosstechnology TDMA scheme energy pattern beacon parameter negotiationbusinessEnergy (signal processing)Degradation (telecommunications)2017 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS)
researchProduct

Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
researchProduct

An evaluation of recent local image descriptors for real-world applications of image matching

2019

This paper discusses and compares the best and most recent local descriptors, evaluating them on increasingly complex image matching tasks, encompassing planar and non-planar scenarios under severe viewpoint changes. This evaluation, aimed at assessing descriptor suitability for real-world applications, leverages the concept of approximated overlap error as a means to naturally extend to non-planar scenes the standard metric used for planar scenes. According to the evaluation results, most descriptors exhibit a gradual performance degradation in the transition from planar to non-planar scenes. The best descriptors are those capable of capturing well not only the local image context, but als…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniSettore INF/01 - InformaticaImage matchingComputer sciencebusiness.industryVisual descriptorsComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONPattern recognition02 engineering and technology03 medical and health sciences0302 clinical medicineLocal Image Descriptors; Image MatchingRobustness (computer science)Computer Science::Computer Vision and Pattern RecognitionComputer Science::Multimedia030221 ophthalmology & optometry0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingArtificial intelligencebusinessImage matching Data-driven approach Descriptors Evaluation results Local descriptors Local image descriptors Performance degradation Real-worldScene structure Computer vision
researchProduct

The organic carbon derived from sewage sludge as a key parameter determining the fate of trace metals.

2007

8 pages; International audience; In a sandy agricultural soil of south-west of France, continuously cultivated with maize and amended with sewage-sludge over 20 years, the behavior of three trace metals (Cu, Pb, and Zn) was studied during the sludge applications (1974-1993) and after its cessation (1993-1998). Using the delta13C analysis, the dynamics of different sources of organic matter were followed in order to elucidate the influence of the sludge-derived organic matter on the fate of trace metals in the soil and its particle size fractions. This study revealed that sludge-derived organic matter contributed to the formation of macroaggregates through the binding of preexisting microagg…

Sewage-sludgeHealth Toxicology and Mutagenesis010501 environmental sciencesChemical FractionationMESH : Carbon01 natural sciencesMESH : Soil Pollutants[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/GeochemistryMESH : Particle SizeSoil PollutantsTotal organic carbonchemistry.chemical_classificationCarbon IsotopesParticle-size fractionsSewage04 agricultural and veterinary sciencesGeneral MedicineMESH: Metals HeavyPollutionSoil contamination6. Clean water[ SDE.MCG ] Environmental Sciences/Global ChangesEnvironmental chemistryMESH : Metals HeavyFranceValorisationMESH : Carbon IsotopesMESH: Nitrogen IsotopesMESH : FertilizersEnvironmental Engineering[SDE.MCG]Environmental Sciences/Global Changesd13CAmendment[ SDV.SA.SDS ] Life Sciences [q-bio]/Agricultural sciences/Soil studychemistry.chemical_elementMESH: CarbonZincMESH: Fertilizers[SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil studyMESH: Chemical FractionationTrace metalsMetals HeavyEnvironmental ChemistryOrganic matterMESH: Particle SizeParticle SizeMESH : FranceFertilizersOrganic carbonMESH: Sewage0105 earth and related environmental sciencesMESH : Nitrogen IsotopesMESH: Soil PollutantsNitrogen IsotopesMESH : Chemical FractionationPublic Health Environmental and Occupational HealthEnvironmental engineeringMESH: Carbon IsotopesGeneral ChemistryBiodegradation[ SDU.STU.GC ] Sciences of the Universe [physics]/Earth Sciences/Geochemistry[SDE.ES]Environmental Sciences/Environmental and SocietyCarbonMESH: FrancechemistryMESH : Sewage040103 agronomy & agriculture0401 agriculture forestry and fisheriesSludge[ SDE.ES ] Environmental Sciences/Environmental and Society
researchProduct

High-Quality Whole-Genome Sequence of an Estradiol-Degrading Strain, Novosphingobium tardaugens NBRC 16725

2019

In this work we report the complete sequence and assembly of the estradiol-degrading bacterium Novosphingobium tardaugens NBRC 16725 genome into a single contig using the Pacific Biosciences RS II system.

Sewage-treatment plant010501 environmental sciencesBiologymedicine.disease_cause01 natural sciencesGenomeDegradation03 medical and health sciencesComplete sequenceImmunology and Microbiology (miscellaneous)GeneticsmedicineMolecular Biology030304 developmental biology0105 earth and related environmental sciencesGeneticsWhole genome sequencing0303 health sciencesBacteriaStrain (chemistry)ContigGenome Sequencesfood and beveragesbiology.organism_classificationNovosphingobium tardaugensActivated-sludgePacific biosciencesBacteriaMicrobiology Resource Announcements
researchProduct

Sequence stratigraphy of a mesozoic carbonate platform-to-basin system in Western sicily

2009

Abstract Sequence stratigraphic studies of the Triassic through Paleogene carbonate successions of platform, slope and basin in western Sicily (Palermo and Termini Imerese Mountains) have identified a sedimentary cyclicity mostly caused by relative oscillations of sea level. The stratigraphic successions of the Imerese and Panormide palaeogeographic domains of the southern Tethyan continental margin were studied with physical-stratigraphy and facies analysis to reconstruct the sedimentary evolution of this platform-to-basin system. The Imerese Basin is characterized by a carbonate and siliceous-calcareous succession, 1200–1400m thick, Late Triassic to Eocene in age. The strata display a typ…

Shelf-to-basin system sedimentologyQE1-996.5tectono-eustatic cyclesSettore GEO/02 - Geologia Stratigrafica E SedimentologicaCarbonate platformTransgressive/regressive cyclesGeologyEnvironmental Science (miscellaneous)Paleontologychemistry.chemical_compoundchemistryContinental marginFaciesTectono-eustatic cycleGeneral Earth and Planetary SciencesCarbonateSedimentary rockSequence stratigraphyProgradationMesozoic western SicilyPaleogeneGeology
researchProduct

Ion-Induced Energy Pulse Mechanism for Single-Event Burnout in High-Voltage SiC Power MOSFETs and Junction Barrier Schottky Diodes

2020

Heavy ion data suggest that a common mechanism is responsible for single-event burnout in 1200 V power MOSFETs and junction barrier Schottky diodes. Similarly, heavy ion data suggest a common mechanism is also responsible for leakage current degradation in both devices. This mechanism, based on ion-induced, highlylocalized energy pulses, is demonstrated in simulations and shown to be capable of causing degradation and singleevent burnout for both the MOSFETs and JBS diodes. peerReviewed

SiCpowerMOSFETdiodeSEBsäteilyfysiikkasilicon carbidepuolijohteetsingle-event burnoutionisoiva säteilydioditheavy iondegradation
researchProduct

Corrigendum to “The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of PMMA” [Polym Degrad S…

2012

Silica nanoparticlesMaterials scienceMorphology (linguistics)Polymers and PlasticsChemical engineeringDegradation kineticsMechanics of MaterialsThermalMaterials ChemistryNanotechnologyCondensed Matter PhysicsStabPolymer Degradation and Stability
researchProduct