Ion‐Mobility Spectrometry Can Assign Exact Fucosyl Positions in Glycans and Prevent Misinterpretation of Mass‐Spectrometry Data After Gas‐Phase Rearrangement

The fucosylation of glycans leads to diverse structures and is associated with many biological and disease processes. The exact determination of fucoside positions by tandem mass spectrometry (MS/MS) is complicated because rearrangements in the gas phase lead to erroneous structural assignments. Here, we demonstrate that the combined use of ion‐mobility MS and well‐defined synthetic glycan standards can prevent misinterpretation of MS/MS spectra and incorrect structural assignments of fucosylated glycans. We show that fucosyl residues do not migrate to hydroxyl groups but to acetamido moieties of N‐acetylneuraminic acid as well as N‐acetylglucosamine residues and nucleophilic sites of an anomeric tag, yielding specific isomeric fragment ions. This mechanistic insight enables the characterization of unique IMS arrival‐time distributions of the isomers which can be used to accurately determine fucosyl positions in glycans.     

New approach to chemical modification of PIM-1 for gas separation membranes

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Sulfobetaine derivatives of thiacalix[4]arene: synthesis and supramolecular self-assembly of submicron aggregates with AgI cations

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Pseudo-Effect Algebras as Total Algebras

It is shown that every pseudo-effect algebra can be organized as a total algebra. In general, this total algebra is not unique, but it always determines the original partial addition. Special attention is paid to lattice-ordered pseudo-effect algebras for which the total operations can be defined in a unique natural way and this allows one to characterize pairs of compatible elements.     

Interaction between thallium(III) bromide and dicyclohexano-18-crown-6 immobilized on silica

The adsorption of cis-syn-cis-dicyclohexano-18-crown-6 on silica gel from organic solvents was studied. In the adsorption from chloroform solutions, the immobilization of the reagent molecules at the surface was coplanar. Hydrogen bonds between surface silanol groups and oxygen atoms of the polyether ring of the crown ether play an important role in the immobilization of the reagent. The reaction between thallium(III) bromide and the immobilized reagent was studied. The composition of complex compounds formed at the surface of the modified adsorbent was found. A procedure was proposed for the sorption-spectrophotometric determination of thallium(III) (≥0.05 mg/L) in the presence of heavy metal ions.     

On some iterations for optimal control of jump linear equations

We consider different iterative methods for computing Hermitian solutions of the coupled Riccati equations of the optimal control problem for jump linear systems. We have constructed a sequence of perturbed Lyapunov algebraic equations whose solutions define matrix sequences with special properties proved under proper initial conditions. Several numerical examples are included to illustrate the effectiveness of the considered iterations.     

Effective-mass superlattice as an injector in quantum cascade lasers

In this paper, we have developed new design of the injector for quantum cascade structures based on the effective mass superlattice. The transmission spectra of the conventional injector and effective-mass injector have been compared. Advantage of the effective-mass injector is more uniform spectrum of pass-band. This feature allows to improve controllability of the quantum cascade laser, to increase stability of its operation and to decrease sensitivity to noise in applied voltage bias. Also, we have computed geometrical parameters for effective-mass injector which is appropriate to provide inverted population in existing quantum-cascade lasers. Such injector should be characterized by 15–25 numbers of layers with widths of layers up to 2 nm.     

Switched system modeling and robust steering control of the tail end phase in a hot strip mill

In this article, a robust steering control for the last phase of the rolling process in a hot strip mill is proposed. This phase, called tail end phase, may be modelled as a linear switched system. The switchings make the system unstable and the task of the tail end steering control consists in guaranteeing the safety of the industrial plant. The system involves a two time scales dynamics. Hence, the singular perturbation method is used in order to design the control law. The controller has to take into account the physical variations of the rolled products and an uncertainty in the switching time. Results concerning the ArcelorMittal hot strip mill of Eisenhüttenstadt are presented.     

Surface structure of nascent particles of ultrahigh molecular weight poly(ethylene) reactor powders

Physics of the Solid State - A comparative investigation of the surface structure of three ultrahigh molecular weight poly(eth-ylene) (UHMWPE) reactor powders that differ by their ability to be...