A cutting plane algorithm for the Capacitated Connected Facility Location Problem

We consider a network design problem that arises in the cost-optimal design of last mile telecommunication networks. It extends the Connected Facility Location problem by introducing capacities on the facilities and links of the networks. It combines aspects of the capacitated network design problem and the single-source capacitated facility location problem. We refer to it as the Capacitated Connected Facility Location Problem. We develop a basic integer programming model based on single-commodity flows. Based on valid inequalities for the capacitated network design problem and the single-source capacitated facility location problem we derive several (new) classes of valid inequalities for the Capacitated Connected Facility Location Problem including cut set inequalities, cover inequalities and combinations thereof. We use them in a branch-and-cut framework and show their applicability and efficacy on a set of real-world instances.     

Definitive Carbon-13 Chemical Shift Assignments in 2-Substituted Adamantane Derivatives by Deuterium Isotope Effects

Deuterium isotope effects on carbon-13 chemical shifts in 5-[²H]-isotopomeres of ten 2-substituted adamantane derivatives were determined and used for complete assignment of their carbon-13 NMR spectra.

The carbon-13 NMR spectra of ten 2-substituted adamantane derivatives have been assignated by consideration of deuterium isotope effects. Some four- and five-bond downfield deuterium effects on certain chemical shifts have been measured and attributed to remote hyperconjugative interactions.     

Monitoring the Process of Crystallization and Determination of the Degree of Crystallinity of NaA Zeolites by Infrared Spectroscopy

Abstract

The course of crystallization and the degree of crystallinity of NaA zeolite, as well as its modified forms after treatment with HCl can be monitored by infrared cpectroscopy. As internal standard the band at 470cm^?1, due to vibrations in the SiO₄ tetrahedron may be used. During the crystallization process the amount of double fourfold rings (D4R) in the alumino-silicate gel increases which can be followed by the IR band at 560cm^?1. The ratio of intensity of this band and the one at 470cm^?1 increases in the course of crystallization.     

Structure of the Semi-Classical Amplitude for General Scattering Relations

ABSTRACT

We consider scattering by general compactly supported semi-classical perturbations of the Euclidean Laplace-Beltrami operator. We show that if the suitably cut-off resolvent quantizes a Lagrangian relation on the product cotangent bundle, the scattering amplitude quantizes the natural scattering relation. In the case when the resolvent is tempered, which is true at non-trapping energies or at trapping energies under some non-resonance assumptions, and when we work microlocally near a non-trapped ray, our result implies that the scattering amplitude defines a semiclassical Fourier integral operator associated to the scattering relation in a neighborhood of that ray. Compared to previous work, we allow this relation to have more general geometric structure.     

Evolution of polyaniline nanotubes: the oxidation of aniline in water

The course of aniline oxidation with ammonium peroxydisulfate in aqueous solutions has been investigated. The reaction was terminated at various times and the intermediates collected. Besides the precipitates, the films deposited in situ on silicon windows have also been studied. The kinetic course of polymerization is controlled by the acidity level, which changes during the polymerization from pH 8 to a final value close to pH 1. It has two distinct exothermic phases. Gel-permeation chromatography indicates that aniline oligomers are produced at first at high pH, while polyaniline follows after the pH becomes sufficiently low. The growth of polyaniline nanotubes was observed by optical microscopy and confirmed by electron microscopy. The molecular structure of the reaction intermediates was studied in detail by FTIR spectroscopy. Oxidation products are markedly sulfonated, and they contain phenazine units. Aniline oligomers are more soluble in chloroform than the polymer fraction, which contains nanotubes.     

C59Si on the monohydride Si(100):H-(2 x 1) surface

We propose the use of the Si atom in the experimentally observed C59Si molecule as a possible way to controllably anchor fullerene molecules on a Si surface, due to the formation of a strong bond to one of the Si surface atoms. All our results are based on ab initio total energy density functional theory, and we obtain that the binding energy is on the order of 2.1 eV, approximately 1.4 eV more stable than a C60 bonded in a similar situation. A possible route to obtain such adsorption via a (C59Si)2 dimer is examined, and we find the whole process to be exothermic by approximately 0.2 eV.     

On matrix mappings into some strong Cesàro sequence spaces

We determine the classes (X, Y_T) of matrix transformations from X into Y_T where X is one of the classical sequence spaces c₀, c, ?_∞ and ?₁ of all null, convergent and bounded complex sequences and all absolutely convergent complex series, T is a triangle, Y_T is the matrix domain of T in Y and Y is any of the sets of all sequences that are summable, summable to zero or bounded by the strong Cesàro method of order 1, with index 1 ? p < ∞. Furthermore, we determine the representations of the general bounded linear operators from c into Y. We also establish estimates for the norms of the operators in each case.     

Chemical characterization of the smallest S-nitrosothiol, HSNO; cellular cross-talk of H2S and S-nitrosothiols

Dihydrogen sulfide recently emerged as a biological signaling molecule with important physiological roles and significant pharmacological potential. Chemically plausible explanations for its mechanisms of action have remained elusive, however. Here, we report that H(2)S reacts with S-nitrosothiols to form thionitrous acid (HSNO), the smallest S-nitrosothiol. These results demonstrate that, at the cellular level, HSNO can be metabolized to afford NO(+), NO, and NO(-) species, all of which have distinct physiological consequences of their own. We further show that HSNO can freely diffuse through membranes, facilitating transnitrosation of proteins such as hemoglobin. The data presented in this study explain some of the physiological effects ascribed to H(2)S, but, more broadly, introduce a new signaling molecule, HSNO, and suggest that it may play a key role in cellular redox regulation.     

Cosmological expansion and local systems: a Lemaître–Tolman–Bondi model

We propose a Lemaître–Tolman–Bondi system mimicking a two-body system to address the problem of the cosmological expansion versus local dynamics. This system is strongly bound but participates in the cosmic expansion and is exactly comoving with the cosmic substratum.