On Asymptotic Stability and Sweeping of Collisionless Kinetic Equations

We study a collisionless kinetic equation describing density distribution function of the position and velocity of particles moving in a slab with finite thickness and with a partly diffusive boundary reflection. In particular, we deal with existence of an invariant density and with the convergence to the equilibrium. We also study the long time behavior of densities when the equilibrium does not exists.     

Computing stable loads for pallets

This paper describes an Integer Programming model for generating stable loading patterns for the Pallet Loading Problem under several stability criteria. The results obtained during evaluation show great improvement in the number of stable patterns in comparison with results reported earlier. Moreover, most of the solved cases also ensure optimality in terms of utilization of a pallet.     

The Baum-Connes Conjecture via Localization of Categories

We redefine the Baum-Connes assembly map using simplicial approximation in the equivariant Kasparov category. This interpretation is ideal for studying functorial properties and gives analogues of the Baum-Connes assembly map for all equivariant homology theories.     

Diffusion of nickel on the (110) region of a tungsten field emitter

The diffusion of nickel atoms on the (110) plane of a thermally cleaned tungsten crystal has been investigated by a field emission technique. The measurements were carried out for low nickel coverage and substrate temperatures T390 K when the nickel atoms escape from the (110) plane to its surroundings. the value of the activation energy obtained, Q=0.96 eV, is discussed taking into account the conditions under which diffusion occurs.     

An ion-imprinted thiocyanato-functionalized mesoporous silica for preconcentration of gold(III) prior to its quantitation by slurry sampling graphite furnace AAS

A gold(III)-imprinted thiocyanato-functionalized silica network of type SBA-15 was prepared by co-condensation of tetraethoxysilane (TEOS) with thiocyanatopropyltriethoxysilane (TCTES) in the presence of Pluronic123 and Au(III) ions. Compared to the non-imprinted material, the imprint has a higher selectivity and adsorption capacity for Au(III). The maximum static adsorption capacity for Au(III) is 475 mg·g^?1 for the ion-imprinted, and 62 mg·g^?1 for the non-imprinted sorbent. The imprint was applied to the sorption of Au(III) from digested geological samples prior to its determination by graphite furnace atomic absorption spectrometry. Adsorption is fast and does not substantially prolong the analytical procedure. Under optimum conditions, the detection limit for Au(III) is 2 ng·g^?1. The method was validated by analyzing certified reference materials, and results were in good agreement with certified values. The procedure was successfully applied to the separation and determination of gold in complex geological samples.

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Graphical abstract Schematic presentation of the preparation of ion-imprinted thiocyanato-functionalized mesoporous silica and its application for the preconcentration of gold from digested soils before its determination by slurry sampling graphite furnace atomic absorption spectrometry (GF AAS).

     

Properties of hydration shells of protein molecules at their pressure- and temperature-induced native-denatured transition.

Properties of water at the surface of biomolecules are important for their conformational stability. The behaviour of hydrating water at protein transition (t) pressures P(t) and temperatures T(t) , with the points (P(t),T(t) ) lying in the Native-Denatured (N-D) transition line, is studied. Hydration shells at the hydrophilic regions of protein molecules with surface charge density sigma are investigated with the help of the equation of state of water in an open system. The local values of sigma rather close to each other (sigma(D) approximately 0.3 C m(-2)) are found for six different experimental lines of the N-D transition found in the literature. The values sigma(D) correspond to the crossings of the total pressure (P(t)+Pi) vs sigma isotherms at different T(t) (Pi-electrostriction pressure). The pressures P(t) and temperatures T(t) appear to be related with some selected sites at the surfaces of the protein molecules.     

Crystal structure of 7-cyano-6,7-dimethyl-1-phenyl-1,3,6,7-tetrahydro-2,1-benzoxaphospole 1-oxide

The crystals (C₁₆H₁₈NO₂P,M _r=287.30) are orthorhombic, space group Pbca witha=8.200(2),b=14.857(2), andc=24.396(5)Å,V=2972.1 ų,Z=8,D _x=1.284 mg m^–3,(MoK)=0.71069 Å,=1.90 cm^–1,F(000)=216,T=295K. FinalR=0.044 for 1673 observed reflections collected on a diffractometer. Structure solved by direct methods.Cis-junction and double bond in the six-membered ring cause its almost ideal sofa conformation. The two neighboring methyl groups are cis, and cyano substituent is in an equatorial position. There is a shortintramolecular H(o-phenyl)O(endocyclic) contact of 2.53(3)Å and the phenyl ring is in a less favorable rotational orientation due to molecular packing.     

Conformational mobility in chemically-modified cyclodextrins

The observation that per-2,6-O-methyl-3-O-benzoyl--cyclodextrin (1) displays some unusual conformational behaviour in solution has led to a detailed investigation by (dynamic) NMR spectroscopy of the equilibration process that occurs in solutions of per-2,3-O-benzoyl--cyclodextrin (3) and some related compounds (7–9) between conformational isomers with averagedC ₆ andC ₃ molecular symmetries in certain organic solvents such as benzene, dichloromethane, and chloroform. The solvent dependence of the conformational equilibrium is also reflected in a spread of values for the specific optical rotations for 3 from +9° in 1,1,2,2-tetrachloroethane, where there is a degenerate equilibrium between species withC ₃ molecular symmetry, to +92° in acetone where a species with averagedC ₆ symmetry is present.This paper is dedicated to the memory of the late Dr C. J. Pedersen.