Search results for "Phase"

showing 10 items of 6344 documents

Surfactant self-assembling in the gas phase: bis(2-ethylhexyl)- sulfosuccinate divalent metal ion anionic aggregates

2012

RATIONALE: Investigation of fundamental aspects driving surfactant self-assembling and of the capability of including guest molecules or ions in their micellar aggregates is an exciting research field for theoretical and technological reasons. In this light, assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ion chlorides have been investigated in the gas phase by electrospray ionization mass spectrometry in negative ion mode, tandem mass spectrometry and energy-resolved mass spectrometry. METHODS:Water/methanol solutions of AOTNa and chloride salts of nickel, magnesium, calcium and manganese, with different AOTNa/metal salt ratios, …

surfactant self-assembling gas phase divalent metal ion anionic aggregates mass spectrometrySettore CHIM/06 - Chimica Organica
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Gas Phase Charged Aggregates of Bis(2-ethylhexyl)sulfo-succinate (AOT) and Divalent Metal Ions. First evidence of AOT solvated aggregates

2011

Assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ions have been investigated in the gas phase by electrospray ionization mass spectrometry. A variety of positively charged monometallated and mixed metal aggregates are formed. Interestingly, several ions contain solvent (MeOH, H2O) molecules and constitute the most abundant AOT cationic aggregates not containing sodium. These species are the first example of solvated AOT-metal ion aggregates in the gas phase. By increasing the surfactant aggregation number, the abundance of solvated species becomes lower than that of unsolvated ones. Decompositions of ionic species have been studied…

surfactantAOTGas phase aggregateelectrosprayenergy resolved mass spectrometrySettore CHIM/02 - Chimica Fisica
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Review: Mass spectrometry of surfactant aggregates

2011

In contrast with the enormous amount of literature produced during many decades in the field of surfactant aggregation in liquid, liquid crystalline and solid phases, only a few investigations concerning surfactant self-assembling in the gas phase as charged aggregates have been carried out until now. This lack of interest is disappointing in view of the remarkable theoretical and practical importance of the inherent knowledge. The absence of surfactant–solvent interactions makes it easier to study the role of surfactant–surfactant forces in determining their peculiar self-assembling features as well as the ability of these assemblies to incorporate selected solubilizate molecules. Thus, th…

surfactants charged aggregates gas phase reverse micelles mass spectrometry ESI-MS
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Phase retrieval of vitreous floaters: simulation experiment

2020

Knowledge of the structure of vitreous floaters is crucial to evaluate the need for surgical removal of these floaters. We simulated the phase retrieval of microstructures simulating vitreous floaters by an algorithm PhaseLift and investigate the effects of various parameters on the retrieved phase. The object under test was modulated and the coded diffraction patterns were calculated. Next, PhaseLift was used to retrieve the phase. In the current study, we simulate the effect of Gaussian and Poison noise on the phase retrieval of pure phase objects. We apply an iterative algorithm PhaseLift for phase retrieval as this algorithm requires a very few modulating masks and is able to retrieve t…

symbols.namesakeComputer scienceIterative methodGaussian noiseGaussiansymbolsPhase (waves)Shot noisePoisson distributionPhase retrievalAlgorithmNoise (electronics)Optical Design and Testing X
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ChemInform Abstract: Experimental and Theoretical Investigations on Structural and Vibrational Properties of Melilite-Type Sr2ZnGe2O7at High Pressure…

2015

The title compound is characterized by high-pressure powder XRD and Raman scattering measurements up to 22 GPa, and by DFT calculations.

symbols.namesakeCrystallographyChemistryHigh pressurePhase (matter)symbolsengineeringMeliliteGeneral MedicinePowder xrdengineering.materialRaman scatteringMonoclinic crystal systemChemInform
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Raman measurements in the intermediate phase of [N(CH3)4]2ZnI4

1991

Abstract Raman spectra and deviation angle of the indicatrix have been measured in the intermediate phase, between the two transition temperatures T c1 = 255 K and T c2 = 217 K. The results are consistent with the existence, in this phase, of large domains, piled up along the c-axis (Pnma notation).

symbols.namesakeCrystallographyMaterials sciencePhase (matter)symbolsGeneral Materials ScienceRaman spectroscopyInstrumentationPhase Transitions
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Theoretical and Experimental Study of Polarization Modulation Instability in All-Normal Dispersion Photonic Crystal Fibers

2018

Experimental observation of polarization modulation instability in all-normal dispersion photonic crystal fibers is reported. Stokes and anti-Stokes sidebands with spectral shift of 40 nm were observed when the fiber was pumped at 1064 nm. Experimental results are baked by a vectorial four-wave mixing model.

symbols.namesakeFour-wave mixingMaterials sciencesymbolsPhysics::OpticsPolarization modulationSpectral shiftSelf-phase modulationPolarization (waves)InstabilityMolecular physicsRaman scatteringPhotonic-crystal fiberLatin America Optics and Photonics Conference
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Computing the Trace

2001

So far we have been interested in the general expression for the WKB-propagation function. Now we turn our attention to the trace of that propagator, since we want to exhibit the energy eigenvalues of a given potential. From earlier discussions we know that the energy levels of a given Hamiltonian are provided by the poles of the Green’s function:

symbols.namesakeTheoretical physicsComputer sciencesymbolsPropagatorStationary phase approximationGeneral expressionHamiltonian (quantum mechanics)Eigenvalues and eigenvectors
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О проблеме Гарднера для систем управления фазовой автоподстройкой частоты

2019

This report shows the possibilities of solving the Gardner problem of determining the lock-in range for multidimensional phase-locked loops systems. The development of analogs of classical stability criteria for the cylindrical phase space made it possible to obtain analytical estimates of the lock-in range for third-order system. peerReviewed

säätöteoriaphase-locked loopselektroniset piiritnonlinear analysisGardner problem on the lock-in rangefrequency stability criteria
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Convolutional neural networks in skin cancer detection using spatial and spectral domain

2019

Skin cancers are world wide deathly health problem, where significant life and cost savings could be achieved if detection of cancer can be done in early phase. Hypespectral imaging is prominent tool for non-invasive screening. In this study we compare how use of both spectral and spatial domain increase classification performance of convolutional neural networks. We compare five different neural network architectures for real patient data. Our models gain same or slightly better positive predictive value as clinicians. Towards more general and reliable model more data is needed and collection of training data should be systematic. peerReviewed

ta113Training setskin cancerArtificial neural networkComputer sciencebusiness.industryspektrikuvausHyperspectral imagingspectral imagingSpectral domainPattern recognitionneuroverkotmedicine.diseaseneural networksWorld wideConvolutional neural networkihosyöpämedicineArtificial intelligenceSkin cancerEarly phasebusinessta217
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