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Showing 1 to 20 of 291 for “"Relaxation time"”.
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Dielectric relaxation time spectroscopy for tissue characterisation
… caused by distributions of dielectric relaxation time (DRT) constants were made on different types of biological material. It is postulated that widely used approaches for modelling these electrical properties are fundamentally flawed. The research work concentrates on the …
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Profiling of Relaxation Time and Diffusivity Distributions with Low Field NMR
… introduced that allow for the determination of relaxation time or diffusion-relaxation time distributions as a function of sample height. One-dimensional T 2 and D-T 2 profiles can be determined with a low-field Maran Ultra spectrometer by implementing nuclear magnetic resonance imaging …
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Hot Band Rotational Relaxation Time in Carbonyl Sulfide by Transient Infrared-Microwave Double Resonance
Rotational relaxation time (T) has been measured for pure Carbonyl Sulfide (('16)O('12)C('32)S) in a highly vibrationally and rotationally excited state (03('1f)0, J=24). A CO(,2) laser (P(,9)(24) line) was used to pulse excite the OCS gas: (01('1f)0, J=25) (--->) (03('1f)0, J=24). The resulting …
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High Pressure Nuclear Magnetic Relaxation Time Studies of Collision-Limited and Structure-Limited Fluids
Made available in DSpace on 2014-12-13T20:10:51Z (GMT). No. of bitstreams: 1 8009214.pdf: 4679216 bytes, checksum: dbb00d005800281f77b6935d9ea6541b (MD5) Previous issue date: 1979
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Temporal dynamics of hot-electrons in metal films and alloys
… carriers. It has been found that the hot-carrier relaxation time also plays a crucial role in determining the efficiency of these devices. Further, the fast thermalization process of hot-carriers is the primary loss mechanism in hot-carrier devices. Thus, to maximize the device efficiency, we need …
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Carrier relaxation in doped quantum wells
The relaxation time of an electron in a quantum well is derived within the random-phase approximation including full multi-subband and frequency dependent screening. The resulting expression encompasses both electron-electron and electron-phonon scattering taking into account the mutual …
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The role of vortices in the formation of the solar system
… the gas through the Stokes drag force, with the relaxation time specifying how quickly the particle velocity approaches the gas velocity. The particles tend to converge in high pressure vortices and drift out of low pressure systems. The convergence time is dependent on the vortex strength and …
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Depolarized Light Scattering Studies of the Orientational Structure of Liquid Benzene, Dipole-Induced Dipole Models for Molecular Polarizabilities, and the Cotton-Mouton Effect
The orientational relaxation time ((tau)(,LS)) is measured for liquid benzene by depolarized light scattering as a function of temperature and pressure. The values of (tau)(,LS) are compared with the orientational relaxation time as measured by raman scattering ((tau)(,SP)). The ratio …
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Crosslinking and Entanglement Effects in Polybutadiene
Proton relaxation measurements have been used to investigate the effects of crosslinking and entanglements on segmental motion in polybutadiene. The temperature dependence of T(,1), the spin-lattice relaxation time, T(,2), the spin-spin relaxation time, and T(,1(,(rho))), the spin-lattice …
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Dielectric relaxation behavior of poly(3-hydroxybutyrate)
… blending with other polymers which possess high relaxation behavior at room temperature seems attractive. Prior to such development, the fundamental characterization of the relaxation behavior of PHB itself is extremely important in order to assess the effect of any attempt to improve the …
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NMR investigations of ionic host polymer systems
… experimental approach is the use of spin-lattice relaxation time measurements (I H, 7Li and 19F) to act as a probe of structure and dynamics. 19F spin-lattice relaxation time investigations in LiCF3S03 and PEO/LiCF3S03 systems are interpreted in terms of a mechanism in which the hindered …
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Physical Aging and Characterization of Engineering Thermoplastics and Thermoplastic Modified Epoxies
… physical properties, such as physical aging and relaxation time distributions, and chemical structure for a variety of polymeric systems were investigated. Although there is a vast amount of physical aging data for polymers, most of these studies do not attempt to correlate structure with …
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Eliminating critical slowing down in Monte Carlo calculations
… methods have been proposed to shorten the relaxation time and thereby, reduce CSD. These methods all modify site-by-site Metropolis and heat bath Monte Carlo to operate on larger spacial scales. One of these newer techniques is to apply multigrid methods to site-by-site Monte Carlo …
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Measurement of the first internal mode of polystyrene in cyclohexane and toluene through dynamic light scattering
A study of the longest internal relaxation time {dollar}\tau\sb1{dollar} of 8.42 {dollar}\times{dollar} 10{dollar}\sp6{dollar} M{dollar}\sb{\rm w}{dollar} macromolecular polystyrene dissolved in both toluene and cyclohexane was done through the use of photon correlation spectroscopy from scattered …
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Nozzle Flow with Vibrational Nonequilibrium
… freedom. The energy equations are coupled by a relaxation time which measures the time required for the vibrational energy component to equilibrate with the translational and rotational energy components. An improved relaxation time is used in this thesis. The equations are solved numerically …
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Measuring The Nanomechanics Of Nanoconfined Water Layers
… nm thickness of the water film. The retardation time and the relaxation time were measured as a function of both the strain rate and the film thickness. Above a critical strain rate, the retardation time shows valleys, and the relaxation time shows peaks commensurate with the stiffness peaks in …
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Nmr and Polarization Microscopy Studies of Sodium Alkyl Carboxylate Solids and Melts
… measurements and the ('23)Na spin-lattice relaxation time, T(,1), and quadrupole coupling constant,
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Modulation and cross-relaxation effects on the lineshape of strongly saturated nuclear magnetic resonance in solids
… theory. We have measured the dipole spin lattice relaxation time and the cross relaxation time by observing the signal as a function of modulation frequency. This method has the dual advantages of the signal to noise of steady state resonance, and the measurement of time on a frequency scale.
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Sun polarised dynamics in quantum wells
… and some of the parameters governing the spin relaxation dynamics of excitons, heavy-holes and electrons in a number of type I GaAs/AlxGa1-xAs and type I InxGa1-xAs/GaAs single and multiple quantum wells.<br/><br/>The electron, hole and excitonic effective Lande g-factors have been measured as …
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