Search results for "component"

showing 10 items of 1682 documents

Volatile components of aerial parts of Centaurea nigrescens an C. stenolepis growing wild in the Balkans

2010

The volatile constituents of the aerial parts of Centaurea nigrescens Willd, collected in Romania and of two samples of C. stenolepis A. Kerner from Bulgaria and Romania were obtained by hydrodistillation and analyzed. The main components of C. stenolepis were caryophyllene oxide (6.9-15.6%), hexahydrofarnesyl acetone (6.5-4.4%), heptacosane (6.0-4.9%) and p-vinyl guiacol (4.3-5.0%). The main components of C. nigrescens were caryophyllene oxide (9.9%), β-eudesmol (9.5%), spathulenol (7.6%), heptacosane (6.1%) and p-vinyl guiacol (5.5%). The chemotaxonomic significance with respect to their co-location in Sections Lepteranthus and Nigrescentes, respectively, is discussed.

PharmacologybiologyCentaurea stenolepisCentaurea nigrescens Centaurea stenolepis Asteraceae volatile componentscaryophyllene oxide hexahydrofarnesyl acetone beta-eudesmol spathulenol p-vinyl guaiacolCentaureaPlant ScienceGeneral MedicineSettore CHIM/06 - Chimica OrganicaAsteraceaePlant Components Aerialbiology.organism_classificationSpathulenolComplementary and alternative medicineCaryophyllene oxideDrug DiscoveryBotanyCentaurea nigrescensOils VolatilePlant OilsSettore BIO/15 - Biologia FarmaceuticaStenolepisBeta-eudesmol
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High-repetition-rate source delivering optical pulse trains with a controllable level of amplitude and temporal jitters

2020

International audience; We theoretically propose and numerically validate an all-optical scheme to generate optical pulse trains with varying peak-powers and durations. A shaping of the spectral phase thanks to discrete /2 phase shifts enables an efficient phase-to-intensity conversion of a temporal phase modulation based on a two-tone sinusoidal beating. Experiments carried out at telecommunication wavelengths and at a repetition rate of 10 GHz confirm the ability of our approach to efficiently generate a train made of pulses with properties that vary from pulse-to-pulse. The levels of jitters can be accurately controlled.

Phase (waves)FOS: Physical sciences02 engineering and technologyoptical telecommunications01 natural scienceslcsh:QA75.5-76.95010309 optics020210 optoelectronics & photonicsOptics0103 physical sciences0202 electrical engineering electronic engineering information engineeringhigh-repetition rate optical pulse trainsPhysics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]optical component testingRepetition (rhetorical device)business.industryhigh‐repetition rate optical pulse trainsPulse (physics)WavelengthAmplitudelcsh:TA1-2040Trainlcsh:Electronic computers. Computer sciencebusinesslcsh:Engineering (General). Civil engineering (General)Phase modulationOptics (physics.optics)Physics - Optics
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Transition paths between phases IV, III and II of ammonium nitrate predicted from X-ray powder diffractometer and differential scanning calorimeter d…

1994

Abstract Ammonium nitrate solid phase transition paths between phases IV, III and II were explained and predicted on the basis of X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) data by applying partial least-squares regression (PLS) and principal component analysis (PCA). The samples were clustered according to their different transition paths with the PLS and PCA models, and the transition paths were predicted with PLS component clusters. The best PLS clusters were formed by a few first components. Prediction of the transition path with the PLS clusters made a semiquantitative prediction of the transition energy possible. In PCA, principal components 6 and 11, w…

Phase transitionComponent (thermodynamics)Process Chemistry and TechnologyAmmonium nitrateAnalytical chemistryComputer Science ApplicationsAnalytical Chemistrychemistry.chemical_compoundDifferential scanning calorimetrychemistryPowder DiffractometerPartial least squares regressionPrincipal component analysisSpectroscopySoftwarePowder diffractionChemometrics and Intelligent Laboratory Systems
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Solidification Experiments in Single-Component and Binary Colloidal Melts

2009

Phase transitionCrystallographyColloidChemical physicsChemistrySingle componentBinary number
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In Vitro Analysis of the Two-Component System MtrB-MtrA from Corynebacterium glutamicum▿ †

2007

ABSTRACT The two-component system MtrBA is involved in the osmostress response of Corynebacterium glutamicum . MtrB was reconstituted in a functionally active form in liposomes and showed autophosphorylation and phosphatase activity. In proteoliposomes, MtrB activity was stimulated by monovalent cations used by many osmosensors for the detection of hypertonicity. Although MtrB was activated by monovalent cations, they lead in vitro to a general stabilization of histidine kinases and do not represent the stimulus for MtrB to sense hyperosmotic stress.

PhosphataseCorynebacteriumEnzyme ActivatorsMicrobiologyCorynebacterium glutamicumEnzyme activatorBacterial ProteinsOsmotic PressurePhosphorylationMolecular BiologyHistidinebiologyAutophosphorylationRNA-Binding ProteinsCations Monovalentbiology.organism_classificationAdaptation PhysiologicalTwo-component regulatory systemPhosphoric Monoester HydrolasesCorynebacterium glutamicumBiochemistryLiposomesPhosphorylationATP-Binding Cassette TransportersSignal TransductionTranscription Factors
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Oligofluorene with multiple spiro-connections: its and their use in blue and white OLEDs

2019

Bond rotation within molecules is regarded as one of the nonradiative decay pathways and is detrimental to high photoluminescence quantum yields. In this work, a bulky and rigid blue emitter (Spiro-F) with five spiro-carbon linkages is synthesized. Spiro-F can serve not only as an active component of blue organic light-emitting diodes (OLEDs), but also as a host and blue emitter of white OLEDs. The WOLED offers a low turn-on voltage of 3.5 V and a high current efficiency of 3.6 cd A−1, together with CIE coordinates of (0.29, 0.33). This work proves the potential of super-rigid oligofluorene emitters for OLEDs.

PhotoluminescenceChemistrybusiness.industry02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesCatalysis0104 chemical sciencesActive componentMaterials ChemistryOLEDMoleculeOptoelectronics0210 nano-technologybusinessDiodeCommon emitterNew Journal of Chemistry
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Effect of Ga content on luminescence and defects formation processes in Gd3(Ga,Al)5O12:Ce single crystals

2018

The work was supported by the Institutional Research Funding IUT02-26 of the Estonian Ministry of Education and Research and the project 16-15569S of the Czech Science Foundation.

PhotoluminescenceMaterials scienceLuminescenceAnalytical chemistry02 engineering and technologyActivation energy010402 general chemistry01 natural sciencesInorganic ChemistryCrystalCe3+:NATURAL SCIENCES:Physics [Research Subject Categories]Electrical and Electronic EngineeringPhysical and Theoretical ChemistrySpectroscopyMulticomponent garnetsOrganic ChemistryDopingRadioluminescenceAtmospheric temperature range021001 nanoscience & nanotechnologyAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic MaterialsCrystallographyAbsorption bandScintillatorsSingle crystalsDefects0210 nano-technologyLuminescenceOptical Materials
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Scissors modes of two-component degenerate gases: Bose-Bose and Bose-Fermi mixtures

2003

We investigate the scissors modes in binary mixtures of degenerate dilute quantum gases, for both Bose-Bose and Bose-Fermi mixtures. For the latter we consider both the superfluid and normal hydrodynamic and collisionless regimes. We analyze the dependence of the frequencies of the scissors modes and their character as a function of the Bose-Fermi coupling and the trap geometry. We show that the scissors mode can reveal a clear trace of the hydrodynamic behavior of the Fermi gas.

PhysicsCondensed Matter::Quantum GasesCondensed matter physicsComponent (thermodynamics)Condensed Matter::OtherDegenerate energy levelsFOS: Physical sciencesFermionCondensed Matter - Soft Condensed MatterAtomic and Molecular Physics and Opticslaw.inventionSuperfluidityCoupling (physics)lawSoft Condensed Matter (cond-mat.soft)Fermi gasBose–Einstein condensateFermi Gamma-ray Space Telescope
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Co-existence and shell structures of several superfluids in trapped three-component Fermi mixtures

2006

We study the properties of a trapped interacting three component Fermi gas. We assume that one of the components can have a different mass from the other two. We calculate the different phases of the three component mixture and find a rich variety of different phases corresponding to different pairing channels, and simple ways of tuning the system from one phase to another. In particular, we predict co-existence of several different superfluids in the trap, forming a shell structure, and phase transitions from this mixture of superfluids to a single superfluid when the system parameters or temperature is varied. Such shell structures realize superfluids with a non-trivial spatial topology a…

PhysicsCondensed Matter::Quantum GasesPhase transitionCondensed matter physicsComponent (thermodynamics)Condensed Matter - SuperconductivityShell (structure)FOS: Physical sciencesObservable01 natural sciencesMolecular physicsAtomic and Molecular Physics and Optics3. Good health010305 fluids & plasmasSuperfluiditySuperconductivity (cond-mat.supr-con)PairingPhase (matter)0103 physical sciences010306 general physicsFermi gas
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Contribution of the normal component to the thermal resistance of turbulent liquid helium

2015

Previous results for the velocity profile of the normal component of helium II in counterflow are used to evaluate the viscous contribution to the effective thermal resistance. It turns out that such a contribution becomes considerably higher than the usual Landau estimate, because in the presence of vortices, the velocity profile is appreciably different from the Poiseuille parabolic profile. Thus, a marked increase in the contribution of the normal component to the thermal resistance with respect to the viscous Landau estimate does not necessarily imply that the normal component is turbulent. Furthermore, we examine the influence of a possible slip flow along the walls when the radius of …

PhysicsCondensed matter physicsTurbulenceApplied MathematicsGeneral MathematicsThermal resistanceQuantum turbulenceGeneral Physics and AstronomyRadiusHagen–Poiseuille equationVortexPhysics::Fluid DynamicsThermal resistance – Superfluid helium – Quantum turbulence – Normal componentBoundary value problemSettore MAT/07 - Fisica MatematicaSuperfluid helium-4Zeitschrift für angewandte Mathematik und Physik
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