Energy functional depending on elastic strain and chemical composition

In this paper we deal with energy functionals depending on elastic strain and chemical composition and we obtain lower semicontinuity results, existence theorems and relaxation in the spacesH ^1,p(; ⁿ)×L ^q (; ^d) with respect to weak convergence. Our proofs use parametrized measures associated with weakly converging sequences.The research was partially supported by the National Science Foundation under Grants No. DMS-9000133 and DMS-9201215 and also by the Army Research Office and the National Science Foundation through the Center for Nonlinear Analysis.The research was partially supported by the National Science Foundation uncer Grants No. DMs 911572, the AFOSR 91 0301, the ARO DAAL03 92 G 003 and also by the ARO and the NSF through the Center for Nonlinear Analysis.The research was supported by DGICYT (Spain) through Programa de Perfeccionamiento y Movilidad del Personal Investigador and through grant PB90-0245, by the Army Research Office and the National Science Foundation through the Center for Nonlinear Analysis and also by the project EurHomogenization SC1-CT91-0732 of the European Comunity.     

Gradient Young measures generated by sequences in Sobolev spaces

Oscillatory properties of a weak convergent sequence of functions bounded inL ^p , 1 ≤p ≤ ∞, may be summarized by the parametrized measure it generates. When such a measure is generated by the gradients of a sequence of functions bounded inH ^1,p , it must have special properties. The purpose of this paper is to characterize such parametrized measures as the ones that obey Jensen’s inequality for all quasiconvex functions with the appropriate growth at infinity. We have found subtle differences between the casesp < ∞ andp = ∞. A consequence is that any measure determined by biting convergence is in fact generated by a sequence convergent in a stronger sense. We also give a few applications. Research groupTransitions and Defects in Ordered Materials, funded by the NSF, the AFOSR, and the ARO. The work of the second author is also supported by DGICYT (Spain) through “Programa de Perfeccionamiento y Movilidad del Personal Investigador” and through Grant PB90-0245.     

Two-proton multiplets in theN=82 nucleus 62 144 Sm82 from in-beamγ-measurements

In a high sensitivity (,2n) in-beam study of ₆₂ ¹⁴⁴ Sm₈₂, with the Kölner Würfel OSIRIS -detector array including a Compton polarimeter, we have identified the complete two-proton multiplets d ₅ ^2/–2 , d ₅ ^2/–1 g ₇ ^2/–1 , g ₇ ^2/–2 , h_11/2d ₅ ^2/–1 and the 9^– to 4^– members of the h_11·/2g ₇ ^2/–1 multiplet.Work partially supported by CICYT (Spain).     

An introduction to population approaches for optimization and hierarchical objective functions: A discussion on the role of tabu search

Population approaches suitable for global combinatorial optimization are discussed in this paper. They are composed of a number of distinguishable individuals called "agents", each one using a particular optimization strategy. Periods of independent search follow phases on which the population is restarted from new configurations. Due to its intrinsic parallelism and the asynchronicity of the method, it is particularly suitable for parallel computers. Results on two test problems are presented in this paper. The individual search optimization strategies for each agent have been chosen having the basic characteristics of tabu search. This has been done in order to avoid mixing the hypothesized properties of these population approaches with those of more elaborate tabu search strategies, but remarking on its main characteristics. A set of four test problem "landscapes" is discussed and their use to improve and benchmark the results by using tabu search as the individual optimization strategy within a population heuristic is suggested and explored. The application of tabu search to new problem areas, like molecular biology, is also investigated.     

Germanium speciation by LC-HG-ICP/OES

Liquid chromatography-hydride generation-inductively coupled plasma optical emission spectroscopy (LC-HG-ICP/OES) has been used to determine inorganic and organometallic species of germanium. In recent studies these coupled systems has been applied successfully to the speciation of arsenic. To establish separation conditions for germanium two reversed stationary phases and different solvent mixtures for elution, in isocratic or gradient mode have been tested. The reduction of germanium species to the corresponding volatile hydride is a critical step, especially for acidity control, thus the conditions for reduction using different concentrations of acid have been studied systematically. For the conditions established quality parameters as limit of detection (at the g l^–1 level), precision and recovery have been determined for the germanium species considered in a saline matrix.     

Development and validation of a liquid chromatography-ultraviolet absorbance detection assay using derivatisation for the novel marine anticancer agent ES-285 x HCl [(2S,3R)-2-amino-3-octadecanol hydrochloride] and its pharmaceutical dosage form

ES-285 x HCl [(2S,3R)-2-amino-3-octadecanol hydrochloride] is a novel investigational anticancer agent, which has shown in vitro and in vivo cytotoxic activity against various tumor cell lines with selectivity for certain solid tumors. The pharmaceutical development of ES-285 x HCl warranted the availability of an assay for the quantification and purity determination of ES-285 x HCl active pharmaceutical ingredient (API) and its pharmaceutical dosage form. A liquid chromatographic method (LC) comprising of derivatisation of ES-285 x HCl with phenylisothiocyanate and UV-detection was developed. The method was found to be linear, precise and accurate. The assay also proved selectivity as determined by analysing ES-285 x HCl in combination with 15 analogues and in combination with hydroxypropyl-beta-cyclodextrin, the excipient used in the lyophilised pharmaceutical dosage form. Stress testing showed that the degradation products were separated from the parent compound, confirming its stability indicating capacity. The method was found robust as determined with design of experiments (DoE), which made it possible to predict system suitability responses in worst case experimental conditions and to define criteria for system suitability testing.     

Synthesis of different chiral amino gamma-butyrolactones and amino gamma-butenolides

Different transformations of chiral epoxy esters 1 afford two different amino gamma-butyrolactones 2 and 6, and amino gamma-butenolides 8, by different nucleophilic opening-closing processes. [reaction: see text]