Search results for " barrier"

showing 10 items of 540 documents

Collapse in the symmetric Gross–Pitaevskii equation

2004

A generic mechanism of collapse in the Gross–Pitaevskii equation with attractive interparticle interactions is gained by reformulating this equation as Newton's equation of motion for a system of particles with a constraint. 'Quantum pressure' effects give rise to formation of a potential barrier around the emerging singularity, which prevents a fraction of the particles from falling into the singularity. For reasonable initial widths of the condensate, the fraction of collapsing particles for spherically symmetric traps is found to be consistently about 0.7.

Condensed Matter::Quantum GasesPhysicsPhysics and Astronomy (miscellaneous)Equations of motionCollapse (topology)Atomic and Molecular Physics and Opticslaw.inventionGross–Pitaevskii equationSingularityClassical mechanicslawRectangular potential barrierMatter waveWave functionBose–Einstein condensateJournal of Optics B: Quantum and Semiclassical Optics
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Behaviour of Nb2O5/PPy contacts: From Schottky barriers to p-n junctions

2009

In this work, a study of the photoelectrochemical responses of Nb O /PPy contacts fabricated in both organic 2 5 and aqueous solutions is performed. From the comparison between the experimental data of PPy photodeposited on Nb O in organic and in aqueous solutions, it is evident that the medium used for the photodeposition 2 5 influences the absorption coefficient, the band gap and flat band potential values.

Conductive polymerAqueous solutionMaterials scienceBand gapPhotoconductivityPhotoelectrochemistryAnalytical chemistrySchottky diodePolypyrrolePolypyrrole Nb O thin films Schottky barriers p-n junctions.chemistry.chemical_compoundchemistryElectronic engineeringThin film2009 3rd ICTON Mediterranean Winter Conference (ICTON-MW)
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Histoincompatibility reactions in the hydrocoral Millepora dichotoma

1983

The xenogeneic- and allogeneic immunological specificity of the hydrocoral Millepora dichotoma has been investigated. Xenogeneic histoicompatibility reactions have been observed between this hydrocoral and a series of species belonging to the Demospongiae and to the Anthozoa (both Hexacorallia and Octocorallia). The xenogeneic histoincompatibility reactions proceed in the following sequence: (a) Species-unspecific sensitization; (b) necrosis formation, which is very likely due to an autolytic process; (c) callus formation, due to an hyperplastic growth of stolons; and (d) formation of a contact barrier in form of a barrier layer or a restored stolonial layer. Allogeneic histoincompatibility…

Contact barrierHexacoralliabiologyOctocoralliaCallus formationAnthozoaMillepora dichotomaAnatomyAquatic Sciencebiology.organism_classificationMolecular biologyCoral Reefs
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Syntheses, Structures, Magnetic Properties, and Density Functional Theory Magneto-Structural Correlations of Bis(μ-phenoxo) and Bis(μ-phenoxo)-μ-acet…

2013

The bis(mu-phenoxo) (FeNiIII)-Ni-II compound [Fe-III(N-3)(2)LNiII(H2O)(CH3CN)](ClO4) (1) and the bis(mu-phenoxo)-mu-acetate/bis(mu-phenoxo)-bis(mu-acetate) (FeNiII)-Ni-III compound {[Fe-III(OAc)LNiII(H2O)(mu-OAc)](0.6)center dot[(FeLNiII)-L-III(mu-OAc)(2)](0.4)}(ClO4)center dot 1.1H(2)O (2) have been synthesized from the Robson type tetraiminodiphenol macrocyclic ligand H2L, which is the [2 + 2] condensation product of 4-methyl-2,6-diformylphenol and 2,2'-dimethy1-1,3-diaminopropane. Single-crystal X-ray structures of both compounds have been determined. The cationic part of the dinuclear compound 2 is a cocrystal of the two species [Fe-III(OAc)LNiII(H2O)(mu-OAc)](+) (2A) and [(FeLNiII)-L-I…

Coordination ClustersCopper(Ii) ComplexesSingle-Molecule MagnetTransition-Metal-ComplexesChemistryStereochemistryTheoretical ExplorationExchange InteractionsCationic polymerizationCocrystalAnisotropy BarrierInorganic ChemistryCrystallographyFerromagnetismAntiferromagnetismLanthanide ComplexesDensity functional theoryMacrocyclic ligandPhysical and Theoretical ChemistrySpin Ground-StateGaussian-Basis SetsInorganic Chemistry
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Socio-Cultural Power Dynamics and Coping Functions: A Narrative Case Report of a Female Paralympian

2012

Purpose: This case study explores the lived experiences of an elite female Paralympic powerlifting athlete. The focus is on restrictions and coping responses employed to manage the daily hassles within the cultural and ethnic requirements for achieving athletic excellence. Methods: With an unstructured interview, the narrative was acquired which ranged to a total of 75 minutes (approx) and 20 single spaced pages. The data was analyzed using Foucauldian discourse analysis in conjuncture to feminist poststructuralist theory. Results: The results highlight the issues relating to femininity, culture and ethnicity with regard to athletic career. The analysis elicits extracts from the narrative t…

Coping (psychology)AthleticismCulture BarriersComputer sciencemedia_common.quotation_subjectCoping SkillsEthnic groupCase ReportAdvertisingFemininityUnstructured interviewFemininityExcellenceEliteEthnicityOrthopedics and Sports MedicineNarrativeFoucauldian discourse analysisSocial psychologymedia_commonAsian Journal of Sports Medicine
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Absence of structure in the $^{20,22}$Ne + $^{118}$Sn quasi-elastic barrier distribution

2005

Abstract Motivated by the extreme deformation parameters of the projectile, we have measured quasi-elastic scattering for 20 Ne +  118 Sn. In contrast to calculations based on known collective states, the experimental barrier distribution is structureless. A comparison with the system 22 Ne +  118 Sn shows that this smoothing is unlikely to be due to nucleon- or α -transfer channels, and is more likely to be due to coupling to many other weak channels.

CouplingNuclear reactionPhysicsNuclear and High Energy PhysicsElastic Barrier010308 nuclear & particles physicsScattering22Ne[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciencesCoupled channelsElectric fieldQuasi-elastic scattering0103 physical sciencesIsotopes of tin20Ne25.70.Bc; 25.70.Hi; 25.70.JjDeformation (engineering)Atomic physics010306 general physicsNucleonCoulomb barrier distribution
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Chapter 13 : Marshalling Resources and Dynamic Capabilities to Overcome Innovative Barriers and Foster Creativity in the Service Sector

2013

Understanding the economic implication of creative individuals and firms is at the heart of the new economy and of related fields such as the economics of knowledge, the economics of science and innovation management. This book brings together a panel of theoretical and empirical contributions which address the generation of creative ideas and their transformation into products and services by firms or universities, as well as the interplay of those organizations in networks and markets. The word 'creativity' has been used a great deal recently in relation to efforts to recover from the global financial crisis and re-launch economic activity. Little has been added to explain how and why an …

CreativityInnovative BarriersService sector[SHS.ECO] Humanities and Social Sciences/Economics and Finance
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1H NMR study of dynamical inequivalence of cations in [C(NH2)3]3Sb2Cl9

2001

Abstract The proton NMR second moment and spin–lattice relaxation time have been studied for polycrystalline tris-guanidinium nonachlorodiantimonate(III) in a wide temperature range. The C 3 reorientation of two types of the cations, hindered by very different potential barriers (20.5 and 54.5 kJ/mol) has been revealed. An unusually large dynamical inequivalence of two cations evidently reflects their different crystalline environments.

CrystallographyNuclear magnetic resonanceChemistryMaterials ChemistrySpin–lattice relaxationProton NMRRectangular potential barrierSecond moment of areaGeneral ChemistryCrystalliteActivation energyAtmospheric temperature rangeCondensed Matter PhysicsSolid State Communications
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Understanding cultural barriers and opportunities for developing new apprenticeship programmes

2020

There is increasing interest in many countries in training models that are practice-oriented and correspond to the needs of the labour market. The new Spanish dual system of apprenticeship (FP Dual) for teaching and learning was first implemented in the Valencia Community in 2012. Although FP Dual enjoys considerable support from institutions and from politicians who believe it has the potential to reduce youth unemployment, the dual system is still in a pilot stage. This report is based on research based in Valencia, to explore the cultural and organisational norms and the barriers and opportunities these afford to introducing apprenticeship. The research included interviews with different…

Cultural barriersPolitical scienceLocal DevelopmentGeneral Medicine:PEDAGOGÍA [UNESCO]ApprenticeshipHumanitiesUNESCO::PEDAGOGÍA
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A DC and small signal AC model for organic thin film transistors including contact effects and non quasi static regime

2017

Abstract We present a compact model for the DC and small signal AC analysis of Organic Thin Film Transistors (OTFTs). The DC part of the model assumes that the electrical current injected in the OTFT is limited by the presence of a metal/organic semiconductor junction that, at source, acts as a reverse biased Schottky junction. By including this junction, modeled as a reverse biased gated diode at source, the DC model is able to reproduce the scaling of the electrical characteristics even for short channel devices. The small signal AC part of the model uses a transmission line approach in order to compute the impedances of the channel and parasitic regions of the device. The overlap capacit…

DC modelMaterials scienceContact effectsparasitic capacitanceSchottky barrierOrganic thin film transistors02 engineering and technologyHybrid-pi model01 natural sciencesSignalNon-quasi static small signal modelBiomaterialsOrganic thin film transistors; DC model; AC model; Contact effects; parasitic capacitance; Non-quasi static small signal modelParasitic capacitanceTransmission line0103 physical sciencesHardware_INTEGRATEDCIRCUITSMaterials ChemistryAC modelElectrical and Electronic EngineeringElectrical impedance010302 applied physicsbusiness.industryGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsOrganic semiconductorThin-film transistorOptoelectronics0210 nano-technologybusinessOrganic Electronics
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