Search results for "characterization"
showing 10 items of 1054 documents
Block–Savits Characterization and Star Ordering of Exponential Mixtures
2008
Block and Savits (1980) established a characterization of life distributions using the Laplace transform. In this article, we remark that one of the necessary conditions to be IFRA distribution is equivalent to the star ordering of exponential mixtures. It leads to the definition of two new classes of life distributions, called LIFR and LIFRA, and their dual classes: LDFR and LDFRA. It occurs that these classes have many useful aging properties and preserve known reliability operations. Properties of the classes are studied and relations with known classes are established.
Infinite rate mutually catalytic branching in infinitely many colonies: The longtime behavior
2012
Consider the infinite rate mutually catalytic branching process (IMUB) constructed in [Infinite rate mutually catalytic branching in infinitely many colonies. Construction, characterization and convergence (2008) Preprint] and [Ann. Probab. 38 (2010) 479-497]. For finite initial conditions, we show that only one type survives in the long run if the interaction kernel is recurrent. On the other hand, under a slightly stronger condition than transience, we show that both types can coexist.
Structural and dynamical characterization of melt PEO–salt mixtures
2002
Abstract Salt doped poly ethylene oxide (PEO) mixtures were investigated by means of both small angle neutron scattering and QENS techniques aiming to characterize morphological and dynamical features in the melt state. These experimental evidences provide support to the proposed heterogeneous scenario for polymer electrolytes. In particular, the existence of PEO–cation complexes is proposed to play a major role in intramolecular cooperation and intermolecular transient crosslinks, which affects the mixture properties.
Extremal polynomials in stratified groups
2018
We introduce a family of extremal polynomials associated with the prolongation of a stratified nilpotent Lie algebra. These polynomials are related to a new algebraic characterization of abnormal subriemannian geodesics in stratified nilpotent Lie groups. They satisfy a set of remarkable structure relations that are used to integrate the adjoint equations.
Precursors of aza-macrocycles: Characterization of substituted phenanthrolines and related bases. Crystal and molecular structure of dichloro-d i-n-b…
1993
The synthesis, characterization and 1~ NMR spectra of some substituted 1,lO-phenantrolines are described. These are precursors of azacyclophanes which are, along with their metal complexes, insoluble in polar solvents. It is suggested that the use of substituted 2,2’, 6,6’ -bipyrimidines as precursors would lead to soluble macrocycles. The crystal and molecular structure of dichloro-di-n-butyl(2,2’,6,6’-bipyr
Impact of the use of sterically congested Ir(III) complexes on the performance of light-emitting electrochemical cells
2018
International audience; The synthesis, structural and optoelectronic characterization of a family of sterically congested cyclometalated cationic Ir(iii) complexes of the form [Ir(C^N)2(dtBubpy)]PF6 (with dtBubpy = 4,4′-di-tert-butyl-2,2′-bipyridine and C^N = a cyclometalating ligand decorated at the 4-position of the pyridine ring and/or the 3-position of the phenyl ring with a range of sterically bulky substituents) are reported. This family of complexes is compared to the unsubstituted analogue complex R1 bearing 2-phenylpyridinato as cyclometalating ligand. The impact of sterically bulky substituents on the C^N ligands on both the solid state photophysics and light-emitting electrochemi…
US-Elastography for Breast Lesion Characterization: Prospective Comparison of US BIRADS, Strain Elastography and Shear wave Elastography
2020
To evaluate the diagnostic performance of strain elastography (SE) and 2 D shear wave elastography (SWE) and SE/SWE combination in comparison with conventional multiparametric ultrasound (US) with respect to improving BI-RADS classification results and differentiating benign and malignant breast lesions using a qualitative and quantitative assessment. In this prospective study, 130 histologically proven breast masses were evaluated with baseline US, color Doppler ultrasound (CDUS), SE and SWE (Toshiba Aplio 500 with a 7-15 MHz wide-band linear transducer). Each lesion was classified according to the BIRADS lexicon by evaluating the size, the B-mode and color Doppler features, the SE qualit…
The local structure of SOFC materials investigated by X-Ray absorption spectroscopy
2016
This chapter is devoted to the analysis of the local atomic structure of solid oxide fuel cell (SOFC) electrolyte and electrode materials. Among the experimental techniques able to provide information about the local structure of materials, the X-ray absorption spectroscopy has the peculiarity of element selectivity, allowing to investigate the chemical environment of specific atoms embedded in a matrix. Solid oxide electrolytes allow the conduction of ionic charge carriers between the electrodes of a SOFC device; the mechanism of ion conduction depends on the type of carrier, and it is finely tuned-or even only possible-if the solid matrix is suitably tailored by insertion of doping specie…
A geometrical approach for inverting display color-characterization models
2008
— Some display color-characterization models are not easily inverted. This work proposes ways to build geometrical inverse models given any forward color-characterization model. The main contribution is to propose and analyze several methods to optimize the 3-D geometrical structure of an inverse color-characterization model directly based on the forward model. Both the amount of data and their distribution in color space is especially focused on. Several optimization criteria, related either to an evaluation data set or to the geometrical structure itself, are considered. A practical case with several display devices, combining the different methods proposed in the article, are considered …
Hydraulic Characterization of a Pervious Concrete for Deep Draining Trenches
2018
Reduction in pore water pressure is an useful strategy to improve the stability of slopes. Deep draining trenches can be used for this purpose. For the realization of deep trenches, the usual conventional construction techniques are not adequate and the use of adjacent vertical panels, built by means of the methods well-established for diaphragm walls, is necessary. However, unbonded materials (i.e., gravels) cannot be used, because the excavation of a panel adjacent to one already built will cause instability. For this scope a bonded material such as pervious concrete can be used. It must have high permeability; filtering capacity, in order to prevent internal erosion of the soil in which …