1,308 research outputs found
An invariant analytic orthonormalization procedure with applications
No full textWe apply the orthonormalization procedure previously introduced by Bagarello and Triolo [J. Math. Phys. 48, 043505 (2007)] and adopted in connection with coherent states to Gabor frames and other examples. For instance, for Gabor frames, we show how to construct g(x) ∈ L 2(R) in such a way the functions gn(x)=e ian1xg(x+an2), n ∈ Z2 and a some positive real number, are mutually orthogonal. We discuss in some detail the role of the lattice naturally associated with the procedure in this analysis
Local spectral theory for r and s satisfying rnsrn = rj
No full textIn this paper, we analyze local spectral properties of operators R, S and RS which satisfy the operator equations RnSRn = Rj and Sn RSn = Sj for same integers j ≥ n ≥ 0. We also continue to study the relationship between the local spectral properties of an operator R and the local spectral properties of S. Thus, we investigate the transmission of some local spectral properties from R to S and we illustrate our results with an example. The theory is exemplified in some cases
Pressure-Induced Formation of Diblock Copolymer "Micelles" in Supercritical Fluids. A Combined Study by Small Angle Scattering Experiments and Mean-Field Theory. I: the Critical Micellization Density Concept
No full textPolymer and diblock copolymer phase separation in supercritical (SC) fluids was analyzed by developing a mean-field theory. A phenomenological hole theory that was extended to consider the polymer/solvent/vacancy pseudoternary mixture was used to describe the highly compressible SC fluid. In high density, the homogeneous phase was was favored while polymer aggregation was triggered by the reduced polymer-solvent contacts at low densities. The critical solvent density required for the onset of phase separation (CMD) decreased linearly with temperature, with its slope being tightly dependent on solvent and polymer properties
Incidenza del virus del mosaico del tabacco (TMV) sulla produzione del pomodoro in serra
No full text
Note on the local spectral theory for Drazin invertible operators
No full textIn this paper we continue the analysis undertaken in [6] where we have investigated the
transmission of some local spectral properties from R to its Drazin inverse S, when this does exist. In this
paper we consider a similar problem for unbounded operators
Pressure-induced formation of diblock copolymer "micelles" in supercritical fluids. A combined study by small angle scattering experiments and mean-field theory. II. Kinetics of the unimer-aggregate transition
No full textPolymer and diblock copolymer phase separation in supercritical (SC) fluids was analyzed by developing a mean-field theory. A phenomenological hole theory that was extended to consider the polymer/solvent/vacancy pseudoternary mixture was used to describe the highly compressible SC fluid. In high density, the homogeneous phase was was favored while polymer aggregation was triggered by the reduced polymer-solvent contacts at low densities. The critical solvent density required for the onset of phase separation (CMD) decreased linearly with temperature, with its slope being tightly dependent on solvent and polymer properties
Local spectral theory for Drazin invertible operators
No full textIn this paper we investigate the transmission of some local spectral properties from a bounded linear operator R, as SVEP, Dunford property (C), and property (β), to its Drazin inverse S, when this does exist
Fredholm Spectra and Weyl Type Theorems for Drazin Invertible Operators
No full textIn this paper we investigate the relationship between some spectra originating from Fredholm theory of a Drazin invertible operator and its Drazin inverse, if this does exist. Moreover, we study the transmission of Weyl type theorems from a Drazin invertible operator R, to its Drazin inverse S
MORPHOLOGY OF 1-ALKYL-3-METHYLIMIDAZOLIUM HEXAFLUOROPHOSPHATE ROOM TEMPERATURE IONIC LIQUIDS
No full textThe structural organization in selected room temperature ionic liquids, namely (a) butyl-, (b) hexyl- and (c) octyl-3-methylimidazolium hexafluorophosphate, is investigated by means of X-ray diffraction. We find novel experimental evidences of the existence of a high degree of intermediate range order that is associated to nanoscale segregation of the alkyl chains into the charged matrix. The size of these structural heterogeneities depends linearly from the alkyl chain length. A similar behaviour had been observed in other systems, such as normal alcohols. The slope of such dependence provides hints on the nature of the structural organization of these segregated domains
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