Search results for "Elastic"
showing 10 items of 2162 documents
Vibrational properties of 1D- and 3D polynuclear spin crossover Fe(II) urea-triazoles polymer chains and quantification of intrachain cooperativity
2020
Abstract The vibrational dynamics of the iron centres in 1D and 3D spin crossover Fe(II) 4-alkyl-urea triazole chains have been investigated by synchrotron based nuclear inelastic scattering. For the 1D system, the partial density of phonon states has been modelled with density functional theory methods. Furthermore, spin dependent iron ligand distances and vibrational modes were obtained. The previously introduced intramolecular cooperativity parameter H coop (Rackwitz et al, Phys. Chem. Chem. Phys. 2013, 15, 15450) has been determined to −31 kJ mol−1 for [Fe(n-Prtrzu)3(tosylate)2] and to +27 kJ mol−1 for [Fe(n-Prtrzu)3(BF4)2]. The change of sign in H coop is in line with the incomplete an…
A Theoretical Model to Evaluate the Compressive Behaviour of RС Jacketed Columns
2016
Reinforced concrete (RC) jacketing is becoming increasingly common among the different retrofit techniques for poor RC members, due to its economical and practical advantages. Experimental investigations in the literature have shown that the actual axial capacity of RC jacketed members can be substantially lower than that analytically evaluated by adapting the most common theoretical models for confined concrete. This fact can be explained by taking into account the presence of tensile stresses developing in the concrete, due to a mutual interaction between the inner core and the external jacket. This phenomenon is relevant especially in members where the concrete properties of the jacket a…
Time-Dependent Correlation and Response Functions
2014
The dynamics of liquids is discussed with the help of time-dependent correlation functions. They are related to response functions by the fluctuation-dissipation theorem. This theorem enables to relate experimentally measured inelastic scattering data to the Fourier-transformed correlation and response functions. The Laplace transform of the correlation functions can be represented as a continuous fraction with suitable residual terms (memory functions). The projection formalism of Mori and Zwanzig is introduced.
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.
An equivalent single-layer approach for free vibrations analysis of smart laminated thick composite plates
2012
An equivalent single-layer model for the free vibration analysis of smart laminated plates is presented. The electric and magnetic fields are assumed to be quasi-static and third-order in-plane kinematics is employed to adequately take the shear influence into account when the plate thickness increases. The model governing equations are the plate equations of motion written in terms of mechanical primary variables and effective stiffness coefficients, which take the multifield coupling effects into account. The model shows that the surfaces magneto-electric boundary conditions enter the definitions of the laminate forces and moments resultants. Moreover, it reveals that new stiffness terms,…
Breakup and default risks in the great lockdown
2023
Abstract In this paper, we exploit CDS quotes for contracts denominated in different currencies and with different default clauses to estimate the risk of a breakup of the Eurozone and the propagation of breakup and default risks after the COVID-19 shock. Our main result is that the risk of a Eurozone breakup is significant although, quantitatively, it is not larger than in the period before the COVID-19 shock. In addition, we find that an increase in the redenomination risk in one country is associated with an increase in default premia and bond spreads in other Eurozone countries. Finally, we find that a sizeable fraction of the changes in the cost of insuring against redenomination and d…
Reliability Estimation of Optimal Viscoelastic Composite Shells in Critical-Time Calculations
2003
The problem of reliability estimation for optimal viscoelastic composite shells in critical-time calculations is considered. The weight minimization of a viscoelastic composite shell, with constraints on deflections at the critical time, leads to a system deforming unstably, whose deflections grow in time with an increasing rate. A method for estimating the reliability of such shells in calculating the critical time is discussed. This time is regarded as a random variable depending on many, roughly equivalent, factors. An analysis of the reliability is carried out for different values of coefficients of variation, occurring in practice.
DSC, Dilatometric, Dielectric, and1H NMR Studies of Phase Transitions and Molecular Motions in [N(C2H5)4]3M2Cl9 (M = Sb, Bi) Crystals
1995
Results in the dependence of stoichiometry of obtained tetraethylammonium (TEA) chloroantiomonate and chlorobismuthate salts on the molar ratio of reactants used in the synthesis are presented. Seven tetraethylammonium salts are obtained: (TEA) 6 M 8 Cl 30 , TEAMCI 4 , (TEA) 3 M 2 Cl 9 (M = Sb, Bi) and (TEA) 2 SbCl 5 . Preliminary X-ray diffraction studies on (TEA) 3 M 2 Cl 9 (M = Sb, Bi) show that they are isomorphous, crystallizing at room temperature in monoclinic symmetry. The dilatometric, dielectric, and DSC studies show that (TEA) 3 Bi 2 Cl 9 undergoes two phase transitions at T c2 = 144 K and at T c1 = 322 K while (TEA) 3 Sb 2 Cl 9 undergoes three transitions at T c3 = 185, T c2 = 2…
Statics and Dynamics of a Glassy Crystal: A NMR- and Neutron Scattering Investigation of (NaCl) 0.35 (NaCN) 0.65
1987
The statics and the dynamics of the glass transition in (NaCl)0.35(NaCN)0.65 have been investigated by inelastic neutron scattering and are directly compared to NMR results. Insight into the relaxation dynamics is gained via the temperature dependence of the transverse acoustic phonon modes and via the spin relaxation time T1. The statics of the system is reflected by the growth of a central peak and by the distribution of electric-field gradients. Both quantities are directly related to the glass order parameter. The temperature dependence of the order parameter provides experimental evidence that in NaCl:NaCN mixed crystals the glass transition is dominated by random fields rather than by…
Crystal Fields in PrX3 (X=In, Tl, Pb, Sn) Intermetallic Compounds with Cu3Au Structure
1977
We have determined the crystal field splittings of Pr3+ in PrIn3, PrTl3, PrPb3, and PrSn3 by inelastic neutron scattering. The values of the deduced crystal field parameters are found to depend strongly on the constituent X, though all systems have nonmagnetic ground-states. The line widths in the different systems are compared.