Dynamic analysis of frames with viscoelastic dampers modelled by rheological models with fractionalderivatives

Frame structures with viscoelastic dampers mounted on them are considered in this paper. Viscoelastic (VE) dampers are modelled using two, three-parameter, fractional rheological models. The structures are treated as elastic linear systems. The equation of motion of the whole system (structure with dampers) is written in terms of state-space variables. The resulting matrix equation of motion is the fractional differential equation. The proposed state space formulation is new and does not require matrices with huge dimensions. The paper is devoted to determine the dynamic properties of the considered structures. The nonlinear eigenvalue problem is formulated from which the dynamic parameters of the system can be determined. The continuation method is used to solve the nonlinear eigenvalue problem. Moreover, results of typical calculations are presented.     

Electron impact mass spectral study of halogenated N-acetyl- and N-propionylcytisines

(-)-Cytisine and its derivatives, characterised by high affinity to neuronal nicotinic acetylcholine receptors with specificity for the α4β2 subtype, have been shown to be important probes in central nervous system (CNS) research. Electron impact mass spectral (EI-MS) fragmentations of halogenated derivatives of N-acetylcytisine and N-propionylcytisine have been investigated. Detailed fragmentation pathways have been identified for all significant ions including a few characteristic fragment ions. The principal mass spectral fragmentation routes of iodine and bromine compounds have been determined on the basis of low (EI), high resolution (HRD) and B(2)/E linked scan mass spectra as well as linked scans at constant B/E.     

On the pseudo-monotonicity of generalized gradients of nonconvex functions

The paper is devoted to study the class of nonconvex, nondifferentiable functionals on a reflexive Banach space whose generalized Clarke's gradient i s pseudo-monotone i n the sense of Browder-Hess. I n particular, it has been proved that on some restrictions functionals expressed as a pointwise minimum of a finite collection of convex functions belong to this class. Results obtained are used to establish some existence theorems for hemivariational inequalities involving superpotentials under consideration.     

Grüss type inequalities in normed spaces

Generalizations of the classic Grüss inequality in normed spaces are given. The results are illustrated with some specific examples.     

DFT and experimental studies on structure and spectroscopic parameters of 3,6-diiodo-9-ethyl-9H-carbazole

Structural Chemistry - The first report on crystal and molecular structure of 3,6-diiodo-9-ethyl-9H-carbazole is presented. Experimental room-temperature X-ray and 13C chemical shift studies were...     

Stochastic Reaction-diffusion Equations Driven by Jump Processes

We establish the existence of weak martingale solutions to a class of second order parabolic stochastic partial differential equations. The equations are driven by multiplicative jump type noise, with a non-Lipschitz multiplicative functional. The drift in the equations contains a dissipative nonlinearity of polynomial growth.     

Steroidal cyclobutanones

Cycloaddition of dichloroketene and 3-, 7-, 17-, and 20-methylene steroids affords the corresponding cyclobutaneones in yields reflecting the steric crowding around the reacting olefinic double bond.

---

Steroid-Cyclobutaneone (Kurz Mitteilung)

Zusammenfassung Cycloaddition von Dichlorketen an 3-, 7-, 17- und 20-Methylen-Steroide ergab die jeweiligen Cyclobutanonderivate in Ausbeuten, die den sterischen Gegebenheiten rund um die reagierenden olefinischen Doppelbindungen entsprechen.

     

Structure of 6β-hydroxy-4-androsten-3,17-dione monohydrate,C19H27O3·H2O

The structure of the title compound was determined by X-rays:M _r =319.4,P2₁2₁2₁,a=7.753(3),b=10.566(8),c=20.997(10) Å,Z=4 andD _x =1.171 M gm^–3. FinalR=0.042 (R _w =0.041) for 1814 unique reflections. The water molecule is the hydrogen donor to O3 and O17 and an hydrogen acceptor from the O17 hydroxyl group.