Search results for "Linear"

showing 10 items of 7165 documents

Prenatal Ultrastructural Diagnosis in the Neuronal ceroid-lipofuscinoses

1994

Summary The neuronal ceroid-lipofuscinose (NCL) are autosomal-recessive disorders in childhood of unknown enzymatic origin. They can be recognized by the presence of abnormal lipopigments identified by electron microscopy. Based on the study of circulating lymphocytes, individual clinical subtypes of NCL can be correlated. Prenatal diagnosis of NCL with the electron microscope is now feasible for the infantile (Finnish) from (INCL) and late-infantile form (LINCL). INCL-specific granular lipopigments are present in endothelial cells of biopsied chorion stroma vessels of homozygously affected fetuses. In LINCL, disease-typical curvilinear bodies can be identified in uncultured amniotic fluid …

FetusPathologymedicine.medical_specialtyAmniotic fluid cellsCurvilinear bodiesPrenatal diagnosisChorionCell BiologyBiologyAmniotic FluidPathology and Forensic MedicineMicroscopy ElectronStromaNeuronal Ceroid-LipofuscinosesPregnancyPrenatal DiagnosisUltrastructuremedicineHumansFemaleElectron microscopicNeuronal Ceroid-LipofuscinosesPathology - Research and Practice
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Effectiveness of nonlinear optical loop mirrors in chirped fiber gratings compensated dispersion-managed transmission systems

2005

International audience; We show that nonlinear optical loop mirrors can dramatically suppress the side peaks induced by the group delay ripples in chirped fiber gratings compensated dispersion-managed systems and significantly improve the system performance.

Fiber gratingsMaterials sciencegenetic structuresbusiness.industryNonlinear optics02 engineering and technologyTransmission system01 natural sciences010309 opticsLoop (topology)[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryNonlinear optical020210 optoelectronics & photonicsOptics0103 physical sciences[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistry0202 electrical engineering electronic engineering information engineeringOptoelectronicsDispersion managedbusinessDiffraction gratingGroup delay and phase delay
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Modulational instability and domain wall solitons in optical fibers

2000

The first part of this thesis presents some theoretical and experimental results about modulational instability and domain wall solitons in bimodal fibers.In the second part is devoted to the interaction of counter-propagating waves in an isotropic optical fiber

Fibres optiquesbimodale[ PHYS.PHYS.PHYS-ATOM-PH ] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]<br />parois de domainesoptique non linéairebimodal[PHYS.PHYS] Physics [physics]/Physics [physics]Nonlinear Optics[PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph][ PHYS.PHYS ] Physics [physics]/Physics [physics]Optical FiberSolitonsDomain Wall
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Cardiac arrhythmias induced by an electrical stimulation at a cellular level

2008

To provide insights into the impulse propagation between cardiac myocytes, we performed studies of excitation spread with cellular resolution in confluent monolayers of cultured cardiomyocytes (CM). Multisite field potentials have been recorded using microelectrode arrays (MEA) technology in a basal condition and in proarrhythmic conditions induced by a high frequency electrical stimulation. The in vitro observation of spiral waves opens a new way to test the anti-arrhythmic drugs or strategies at cellular level.

Fibrillation0303 health sciencesmedicine.medical_specialtyChemistry[SDV]Life Sciences [q-bio]Stimulation030204 cardiovascular system & hematologyCellular level[SPI]Engineering Sciences [physics]03 medical and health sciencesMicroelectrode0302 clinical medicineCellular resolutionInternal medicinemedicineBiophysicsCardiologyMyocyte[NLIN]Nonlinear Sciences [physics]medicine.symptomComputingMilieux_MISCELLANEOUS030304 developmental biology2008 Computers in Cardiology
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A symmetric Galerkin boundary/domain element method for finite elastic deformations

2000

Abstract The Symmetric Galerkin Boundary Element Method (SGBEM) is reformulated for problems of finite elasticity with hyperelastic material and incompressibility, using fundamental solutions related to a (fictitious) homogeneous isotropic and compressible linear elastic material. The proposed formulation contains, besides the standard boundary integrals, domain integrals which account for the problem's nonlinearities through some (fictitious) initial strain and stress fields required to satisfy appropriate “consistency” equations. The boundary/domain integral equation problem so obtained is shown to admit a stationarity principle (a consequence of the Hu-Washizu one), which covers a number…

Fictitious domain methodMechanical EngineeringLinear elasticityMathematical analysisComputational MechanicsGeneral Physics and AstronomyMixed boundary conditionComputer Science ApplicationsMechanics of MaterialsHyperelastic materialFree boundary problemMethod of fundamental solutionsGalerkin methodBoundary element methodMathematicsComputer Methods in Applied Mechanics and Engineering
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A theoretical study of the collinear reaction F+H2→HF+H using multiconfigurational second-order perturbation theory (CASPT2)

1993

Abstract The second-order perturbation method (CASPT2) with a single state multiconfigurational reference function generated in complete active self-consistent field (CASSCF) calculations has been used to compute the collinear barrier height, saddle point geometry, and exothermicity of the reaction F+H 2 →HF+H. Comparison with full configuration (FCI) calculations with small basis sets shows that the CASPT2 method is capable of reproducing accurately the exact benchmark results correlating seven electrons. Large atomic natural orbital basis sets are used at the seven- and nine-electron level of correlation. With the largest ANO basis set used, F[7s6p5d4f2g]/H[6s5p4d2f], the computed nine-el…

Field (physics)Basis (linear algebra)ChemistryComputational chemistrySaddle pointGeneral Physics and AstronomyOrder (group theory)State (functional analysis)ElectronPhysical and Theoretical ChemistryPerturbation theoryAtomic physicsBasis setChemical Physics
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Horseshoe-shaped maps in chaotic dynamics of long Josephson junction driven by biharmonic signals

2000

Abstract A collective coordinate approach is applied to study chaotic responses induced by an applied biharmonic driven signal on the long Josephson junction influenced by a constant dc-driven field with breather initial conditions. We derive a nonlinear equation for the collective variable of the breather and a new version of the Melnikov method is then used to demonstrate the existence of Smale horseshoe-shaped maps in its dynamics. Additionally, numerical simulations show that the theoretical predictions are well reproduced. The subharmonic Melnikov theory is applied to study the resonant breathers. Results obtained using this approach are in good agreement with numerical simulations of …

Field (physics)BreatherGeneral MathematicsApplied MathematicsChaoticGeneral Physics and AstronomyStatistical and Nonlinear PhysicsNonlinear systemClassical mechanicsBiharmonic equationConstant (mathematics)Nonlinear Sciences::Pattern Formation and SolitonsVariable (mathematics)MathematicsLong Josephson junctionChaos, Solitons &amp; Fractals
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New insights into electron spin dynamics in the presence of correlated noise

2011

The changes of the spin depolarization length in zinc-blende semiconductors when an external component of correlated noise is added to a static driving electric field are analyzed for different values of field strength, noise amplitude and correlation time. Electron dynamics is simulated by a Monte Carlo procedure which keeps into account all the possible scattering phenomena of the hot electrons in the medium and includes the evolution of spin polarization. Spin depolarization is studied by examinating the decay of the initial spin polarization of the conduction electrons through the D'yakonov-Perel process, the only relevant relaxation mechanism in III-V crystals. Our results show that, f…

Field (physics)DephasingElectronsField strengthSpin relaxation and scatteringNoise processes and phenomenaSettore FIS/03 - Fisica Della MateriaMagneticsDistribution theory and Monte Carlo studieElectric fieldElectrochemistryScattering RadiationGeneral Materials ScienceCondensed Matter - Statistical MechanicsPhysicsCondensed matter physicsSpin polarizationChemistry PhysicalRelaxation (NMR)High-field and nonlinear effectCondensed Matter PhysicsSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Condensed Matter - Other Condensed MatterAmplitudeCrystallizationMonte Carlo MethodNoise (radio)Journal of Physics: Condensed Matter
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Cold-Atom-Induced Control of an Optomechanical Device

2010

We consider a cavity with a vibrating end mirror and coupled to a Bose-Einstein condensate. The cavity field mediates the interplay between mirror and collective oscillations of the atomic density. We study the implications of this dynamics and the possibility of an indirect diagnostic. Our predictions can be observed in a realistic setup that is central to the current quest for mesoscopic quantumness.

Field (physics)General Physics and AstronomyFOS: Physical sciencesQuantum entanglementPhysics and Astronomy(all)01 natural sciences010305 fluids & plasmaslaw.invention/dk/atira/pure/subjectarea/asjc/3100lawUltracold atomQuantum mechanics0103 physical sciencesCold Atoms nanodevices entanglement open systemsQuantum information010306 general physicsPhysicsCondensed Matter::Quantum GasesMesoscopic physicsQuantum PhysicsCavity quantum electrodynamicsNonlinear opticsQuantum Gases (cond-mat.quant-gas)Physics::Accelerator PhysicsAtomic physicsCondensed Matter - Quantum GasesQuantum Physics (quant-ph)Bose–Einstein condensate
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Dissipative solitons for mode-locked lasers

2012

International audience; Dissipative solitons are localized formations of an electromagnetic field that are balanced through an energy exchange with the environment in presence of nonlinearity, dispersion and/or diffraction. Their growing use in the area of passively mode-locked lasers is remarkable: the concept of a dissipative soliton provides an excellent framework for understanding complex pulse dynamics and stimulates innovative cavity designs. Reciprocally, the field of mode-locked lasers serves as an ideal playground for testing the concept of dissipative solitons and revealing their unusual dynamics. This Review provides basic definitions of dissipative solitons, summarizes their imp…

Field (physics)NORMAL-DISPERSIONOPTICAL SOLITONSBOUND-STATES01 natural sciencesSIMILARITON FIBER LASERlaw.invention010309 opticsDissipative solitonOpticslawFiber laser0103 physical sciencesGINZBURG-LANDAU EQUATION010306 general physicsNonlinear Sciences::Pattern Formation and SolitonsCAVITY SOLITONSQuantum opticsPhysicsLOCALIZED STRUCTURESbusiness.industrySaturable absorptionLaserAtomic and Molecular Physics and OpticsSATURABLE-ABSORBERElectronic Optical and Magnetic MaterialsBiophotonicsNonlinear Sciences::Exactly Solvable and Integrable SystemsQuantum electrodynamicsDissipative systembusinessTI-SAPPHIRE LASERPULSE ENERGYNature Photonics
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