Chaotic buffering and its mathematical models

We propose a general idea of obtaining different chains of coupled oscillators with chaotic buffering. As examples, we consider chains of diffusively coupled generalized cubic Schrödinger equations and nonlinear telegraph equations. We also give examples of systems that have an infinite-dimensional chaotic attractor.     

Multivariable identification and controller design of an integrated flight control system

This paper investigates the multivariable identification and controller design for the longitudinal channel of a Boeing 747 transport. The transfer function matrix of the system is identified using the prediction error (PE) identification method with multivariable ARX model. An ellipsoidal parametric uncertainty set is constructed from the covariance matrix of the identified parameters. It contains the parameters of actual system at a certain probability level. The identified models and the associated uncertainty sets are validated by measuring the worst-case ν-gap and then compared with the maximum value of the generalized stability margin. In automatic flight control system or autopilots, multiple specifications criteria are needed to be satisfied concurrently, such as good holding (small static altitude holding error), fast response, smooth transition (less oscillation, overshoot). The design of a Multiple Simultaneous Specifications (MSS) controller effectively and practically is a very significant and challenging job. Liu and Mills [H.H.T. Liu, J.K. Mills, Multiple specification design in flight control system, in: Proceedings of the American Control Conference, Chicago, Illinois, 2000, pp. 1365–1369] proposed a MSS controller design method using a convex combination approach. In this paper, we apply the method [H.H.T. Liu, J.K. Mills, Multiple specification design in flight control system, in: Proceedings of the American Control Conference, Chicago, Illinois, 2000, pp. 1365–1369; H.H.T. Liu, Design combination in integrated flight control, in: Proceedings of the American Control Conference, Arlington, Virginia, 2001, pp. 494–499; H.H.T. Liu, Multi-objective design for an integrated flight control system: a combination with model reduction approach, in: Proceedings of IEEE International Symposium on Computer Aided Control System Design, Glasgow, 2002, pp. 21–26] to design a MSS controller based on the identified models of the Boeing 747 transport aircraft longitudinal channel. The controllers are also validated by simulation using the true plant transfer functions.     

Depolymerization of chitin and chitosan in the course of base deacetylation

Depolymerization of chitin and chitosan in the course of deacetylation in an alkaline medium was studied, and the influence exerted on the process by the nature and concentration of the alkali (NaOH, KOH) and salts (NaCl, NaI, KI) was examined.     

Specific features of separate and joint mastication of natural and 1,4-cis-butadiene rubbers in the presence of dibenzoylaminodiphenyl disulfide

Variation of the molecular structure characteristics and properties of natural and 1,4-cis-polybutadiene rubbers (gel content, molecular weight, degree of branching of macromolecules, viscosity) in the course of their separate and joint mastication in the presence of dibenzoylaminodiphenyl sulfide as mastication accelerator or without it was studied.     

Proton–proton bremsstrahlung towards the elastic limit at 190 MeV incident beam energy

A series of nucleon–nucleon bremsstrahlung (NNγ) experiments at 190 MeV incident beam energy have been performed at KVI in order to gain more insight into the dynamics governing the bremsstrahlung reaction. After initial measurements wherein the bremsstrahlung process was studied far away from the elastic limit, a new study was used to probe the process nearer to the elastic limit by measuring at lower photon energies. Measured cross sections and analyzing powers are compared with the predictions of a microscopic model and those of two soft-photon models. The theoretical calculations overestimate the data by up to ≈30%, for some kinematics.     

Mössbauer, X-ray diffraction and magnetization studies of Fe–Mn–Al–Nb alloys prepared by high energy ball milling

Fe₆₀Mn₁₀Al₂₀Nb₁₀, (Fe₆₀Mn₁₀Al₃₀)₉₅Nb₅ and (Fe₆₀Mn₁₀Al₃₀)₉₀Nb₁₀ ball milled powdered alloys were investigated using X-ray diffraction, Mössbauer spectrometry, thermomagnetic (TGM) and magnetization measurements. We studied the influence of Nb content and of different milling times on the structural and magnetic properties. Two main features can be concluded: (1) the FeAlMn induces a BCC phase whatever the Nb content is, and (2) as both increasing Nb content and milling time give rise to an highly disordered state in conjunction with a decrease of the ferromagnetic behavior.     

Non-integrability of some Painlevé VI-equations and dilogarithms

The paper studies the Painlevé VI^e equations from the point of view of Hamiltonian nonintegrability. For certain infinite number of points in the parameter space we prove that the equations are not integrable. Our approach uses recent advance in Hamiltonian integrability reducing the problem to higher differential Galois groups as well as the monodromy of dilogarithic functions.      

Hydrophobicity and thermal stability of fluorinated pentaerythritol esters

Wetting angles and limits of thermal stability of esters derived from pentaerythritol and perfluoro-, ω-chloropolyfluoro-, and perfluoropolyethercarboxylic acids were studied.     

A new class of Ornstein transformations with singular spectrum

It is shown that for any family of probability measures in Ornstein type constructions, the corresponding transformation has almost surely a singular spectrum. This is a new generalization of Bourgain's theorem [J. Bourgain, On the spectral type of Ornstein class one transformations, Israel J. Math. 84 (1993) 53–63], same result is proved for Rudolph's construction [D. Rudolph, An example of a measure-preserving map with minimal self-joining and applications, J. Anal. Math. 35 (1979) 97–122].     

A four-parameter partition identity

We present a new partition identity and give a combinatorial proof of our result. This generalizes a result of Andrews in which he considers the generating function for partitions with respect to size, number of odd parts, and number of odd parts of the conjugate. 2000 Mathematics Subject Classification Primary—05A17; Secondary—11P81