Search results for "Maxim"

showing 10 items of 1236 documents

High performance detector head for PET and PET/MR with continuous crystals and SiPMs

2012

International audience; A high resolution PET detector head for small animal PET applications has been developed. The detector is composed of a 12 mm x 12 mm source continuous LYSO crystal coupled to a 64-channel monolithic SiPM matrix from FBK-irst. Crystal thicknesses of 5 mm and 10 mm have been tested, both yielding an intrinsic spatial resolution around 0.7 mm FWHM with a position determination algorithm that can also provide depth-of-interaction information. The detectors have been tested in a rotating system that makes it possible to acquire tomographic data and reconstruct images of 22Na sources. An image reconstruction method specifically adapted for continuous crystals has been emp…

Nuclear and High Energy Physicsmedicine.medical_specialtySiPMIterative reconstruction01 natural sciencesParticle detectorLyso-030218 nuclear medicine & medical imaging03 medical and health sciences0302 clinical medicineOpticsSilicon photomultiplier0103 physical sciencesmedicineMedical physicsHigh resolution[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det][SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/MicroelectronicsInstrumentationImage resolutionPhysics010308 nuclear & particles physicsbusiness.industryDetectorPosition determinationSemiconductor detectorFull width at half maximumMG-APDPETMonolithic crystalsbusiness
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Evidence for narrow Δ0(1232) states in the 12 C(e,e'pπ−}11 C Reaction

1999

The reaction 12C(e,e'Δ0)11C →12C(e,e'pπ−)11C was investigated at the Mainz Microtron MAMI in a triple coincidence measurement using the three spectrometer setup of the A1 Collaboration. The good missing mass resolution of σm= 0.27 MeV/c2 allowed to select the events belonging to the ground state of 11C. Cutting on these events the excitation energy spectra of 12CΔ0 show evidence for two peaks of about 4 MeV width (FWHM) at 282 MeV and 296 MeV with a significance of about 4.5 standard deviations. The peaks are interpreted in a simple weak coupling model as bound Δ0 states in 12CΔ0.

Nuclear physicsPhysicsNuclear and High Energy PhysicsFull width at half maximumSpectrometerHadronNuclear fusionGround stateMicrotronExcitationSpectral lineThe European Physical Journal A
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Hypernuclear Spectroscopy at JLab Hall C

2010

Abstract Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e'K+) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e'K+) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the “Tilt method” was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7 Λ He and 28 Λ Al together with that of 12 Λ B that achieved resolution better than 500 keV(FWHM) were obtained. The third generation…

Nuclear physicsPhysicsNuclear and High Energy PhysicsParticle physicsFull width at half maximumLuminosity (scattering theory)Electron spectrometerSpectrometerResolution (electron density)Calibrationhypernuclear; electroproduction; kaon spectrometer; electron spectrometerSpectroscopySpectral lineNuclear Physics A
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Tau neutrino mass from semileptonic decays

1981

The semileptonic three particle decays of the tau provide determinations of the tau neutrino mass. The shift of the maximal energy of the observable final state particles islinear in the neutrino mass. The endpoint energy of the pion and a partially integrated decay rate in τ → πωvτ and τ → πρVτ are sensitive to a neutrino mass smaller than 100 MeV. Thus, the present bound on\(m_{v_\tau } \) can significantly be improved.

Nuclear physicsPhysicsParticle physicsMaximal energyPionPhysics and Astronomy (miscellaneous)Tau neutrinoHigh Energy Physics::PhenomenologyParticleHigh Energy Physics::ExperimentObservableNeutrinoEngineering (miscellaneous)Zeitschrift für Physik C Particles and Fields
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Hypernuclear spectroscopy of products from Li-6 projectiles on a carbon target at 2 A GeV

2013

WOS: 000322848900009

Nuclear reaction(Li-6E=2 GeV/nucleonNuclear and High Energy PhysicsMaximum likelihoodWEAK DECAYFOS: Physical sciencesLIFETIMET-1/2. Compared with other datadeduced Lambda massC-12(LAMBDA)H-4)T-1/2measured Lambda H-3H-4 Lambda-hypernuclei invariant mass distribution T-1/2measured LambdaInvariant massNuclear Experiment (nucl-ex)LIGHT HYPERFRAGMENTSSpectroscopyNuclear ExperimentX)PhysicsH-4 Lambda-hypernuclei invariant mass distributionH-3ProjectileSignificance valueslifetime measurementdeduced Lambda mass H-3H-4 Lambda-hypernuclei mass T-1/2. Compared with other data lifetime measurementNUCLEAR REACTIONS C(Li-6Decay timeLAMBDA-HYPERNUCLEIAtomic physicst)NUCLEAR REACTIONS C(Li-6 X) (Li-6 t) (Li-6 H-4) E=2 GeV/nucleonH-4 Lambda-hypernuclei massHypertritonRELATIVISTIC HYPERNUCLEINuclear Physics A
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Acute Type Refinements of Tetrahedral Partitions of Polyhedral Domains

2001

We present a new technique to perform refinements on acute type tetrahedral partitions of a polyhedral domain, provided that the center of the circumscribed sphere around each tetrahedron belongs to the tetrahedron. The resulting family of partitions is of acute type; thus, all the tetrahedra satisfy the maximum angle condition. Both these properties are highly desirable in finite element analysis.

Numerical AnalysisApplied MathematicsDomain decomposition methodsAngle conditionFinite element methodCombinatoricsComputational MathematicsPolyhedronMaximum principleTetrahedronMathematics::Metric GeometryPartition (number theory)Circumscribed sphereMathematicsSIAM Journal on Numerical Analysis
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Power ENO methods: a fifth-order accurate Weighted Power ENO method

2004

In this paper we introduce a new class of ENO reconstruction procedures, the Power ENO methods, to design high-order accurate shock capturing methods for hyperbolic conservation laws, based on an extended class of limiters, improving the behavior near discontinuities with respect to the classical ENO methods. Power ENO methods are defined as a correction of classical ENO methods [J. Comput. Phys. 71 (1987) 231], by applying the new limiters on second-order differences or higher. The new class of limiters includes as a particular case the minmod limiter and the harmonic limiter used for the design of the PHM methods [see SIAM J. Sci. Comput. 15 (1994) 892]. The main features of these new ENO…

Numerical AnalysisConservation lawPhysics and Astronomy (miscellaneous)Applied MathematicsMathematical analysisScalar (physics)Harmonic (mathematics)Computer Science ApplicationsEuler equationsMaxima and minimaComputational Mathematicssymbols.namesakeDiscontinuity (linguistics)Riemann problemModeling and SimulationShock capturing methodsymbolsMathematicsJournal of Computational Physics
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Macroalgal responses to ocean acidification depend on nutrient and light levels

2015

Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityChlorophyll aFucoxanthininorganicAlkalinityPhotosynthetic efficiency standard errorChlorophyll cNitrogen content per dry mass standard errorLight saturation point standard errorPhenolics allTemperature waterCarbon inorganic dissolvedMacroalgaeCalculated using seacarb after Nisumaa et al 2010Carbon Nitrogen ratioAragonite saturation stateAlkalinity totalallCarbon per dry massSalinity standard errortotalCarbon content per dry mass standard errorPhenolics all standard errorCO2 ventChromistapHMaximum photochemical quantum yield of photosystem II standard errorTemperaturePartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedAntioxidant activity standard errorCarbonate ionMaximum photochemical quantum yield of photosystem IIPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Field experimentstandard errorNitrogen content per dry massElectron transport rate standard errorFucoxanthin standard errorEarth System ResearchViolaxanthinPhenolicsChlorophyll a standard errorCarbon dioxide standard errorPotentiometric titrationCalcite saturation stateCarbon/Nitrogen ratio standard errorNitrogenOchrophytaPotentiometricper dry masswaterChlorophyll c standard errorBenthosAlkalinity total standard errorAntioxidant activityElectron transport rateLight saturation pointOcean Acidification International Coordination Centre OA ICCMacro-nutrientsMediterranean SeaNitrogen per dry massBicarbonate ionTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)Primary production PhotosynthesisSpeciespH standard errorCalcite saturation state standard errorCystoseira compressaCalculated using CO2SYSNon photochemical quenchingCarbon content per dry massCarbonate system computation flagViolaxanthin standard errorPrimary production/PhotosynthesisFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonCarbon/Nitrogen ratioBiomass/Abundance/Elemental compositionTreatmentPartial pressure of carbon dioxide water at sea surface temperature wet airAragonite saturation state standard errorCarbon dioxideMacro nutrientsCarbonate ion standard errorSingle speciesFugacity of carbon dioxide water at sea surface temperature wet airPadina pavonicaBiomass Abundance Elemental compositionCoast and continental shelfPhotosynthetic efficiencyBicarbonate ion standard errorNon photochemical quenching standard error
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Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent

2014

We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and delta 13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in…

Ocean Acidification International Coordination Centre (OA-ICC)TemperateSalinityChlorophyll ainorganicAlkalinityLight saturation point standard errorPhotosynthetic quantum efficiencyMediterranean Sea Acidification in a Changing Climate MedSeATemperature waterCarbon inorganic dissolvedCalculated using seacarb after Nisumaa et al 2010IrradianceRespiration rate carbonAragonite saturation stateBiomassAlkalinity totalIrradiance standard errortotalCO2 ventCymodocea nodosapHRespirationEpiphytes loadMaximum photochemical quantum yield of photosystem II standard errorNet community production of carbonTemperaturePartial pressure of carbon dioxide (water) at sea surface temperature (wet air) standard errordissolvedRespiration rate carbon standard errorCarbonate ionMaximum photochemical quantum yield of photosystem IIPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Net community production of carbon standard errorIlluminance standard errorSoft bottom communitystandard errorCarbon inorganic dissolved standard errorRespiration rateElectron transport rate standard errorEarth System Researchδ13CPhotosynthetic quantum efficiency standard errorField observationChlorophyll a standard errorGross primary production of carbonBiomass standard errorCalcium carbonatePotentiometric titrationCalcite saturation stateShoot densityPotentiometricwaterIlluminanceOxygen standard errorBenthosAlkalinity total standard errorMediterranean Sea Acidification in a Changing Climate (MedSeA)Electron transport rateLight saturation pointOcean Acidification International Coordination Centre OA ICCMediterranean SeaGross primary production of carbon standard errorBicarbonate ionSoft-bottom communityδ13C standard errorTemperature water standard errorCalculated using seacarb after Nisumaa et al. (2010)Primary production PhotosynthesisSpeciespH standard errorCarbonate system computation flagloadPrimary production/PhotosynthesisFugacity of carbon dioxide (water) at sea surface temperature (wet air)CarbonBiomass/Abundance/Elemental compositionTreatmentEpiphytes load standard errorOxygenPartial pressure of carbon dioxide water at sea surface temperature wet airEpiphytes loadCarbon dioxideCarbon standard errorEntire communityFugacity of carbon dioxide water at sea surface temperature wet airGroupBiomass Abundance Elemental compositionCoast and continental shelfEpiphytesShoot density standard errorCalcium carbonate standard error
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Natural co-occurrence of ochratoxin A, ochratoxin B and aflatoxins in Sicilian red wines

2015

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (OTA, OTB, AFB1, AFB2, AFG1, AFG2) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l(-1), well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG1, present in 57.9% of sample…

Ochratoxin AAflatoxinAflatoxin B1Health Toxicology and MutagenesisOchratoxin BFood ContaminationWineAverage levelaflatoxin G2Toxicologyaflatoxin G1Sensitivity and SpecificityFluorescencechemistry.chemical_compoundAflatoxinsimmunoaffinity columnFood scienceHPLC/FLD analysiMycotoxinSicilyChromatography High Pressure LiquidWineChromatographyPublic Health Environmental and Occupational HealthGeneral ChemistryGeneral MedicineOchratoxinsimmunoaffinity column wine aflatoxin B-2 aflatoxin G(1) ochratoxin B ochratoxin A aflatoxin B-1 aflatoxin G(2) HPLC/FLD analysischemistryaflatoxin B2Maximum Allowable Concentrationochratoxin Aochratoxin BFood Science
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