Search results for "ESA"

On the zeros of Jacobi polynomials

1994

Impulsive control of the bilinear Schrödinger equation: propagators and attainable sets

2019

International audience; We consider a linear Schrödinger equation with an unbounded bilinear control term. The control term is the derivative of function with bounded variations (impulsive control). Well-posedness results and regularity of the associated propagators follow from classical theory from Kato. As a byproduct, one obtains a topological obstruction to exact controllability of the system in the spirit of the results of Ball, Marsden and Slemrod.

Weaving words for textile museums: the development of the linked SILKNOW thesaurus.

2022

Abstract The cultural heritage domain in general and silk textiles, in particular, are characterized by large, rich and heterogeneous data sets. Silk heritage vocabulary comes from multiple sources that have been mixed up across time and space. This has led to the use of different terminology in specialized organizations in order to describe their artefacts. This makes data interoperability between independent catalogues very difficult. To address these issues, SILKNOW created a multilingual thesaurus related to silk textiles. It was carried out by experts in textile terminology and art historians and computationally implemented by experts in text mining, multi-/cross-linguality and semanti…

Organelle pH studies using targeted avidin and fluorescein–biotin

2000

Abstract Background: Mammalian organelles of the secretory pathway are of differing pH. The pH values form a decreasing gradient: the endoplasmic reticulum (ER) is nearly neutral, the Golgi is mildly acidic and the secretory granules are more acidic still (∼pH 5). The mechanisms that regulate pH in these organelles are still unknown. Results: Using a novel method, we tested whether differences in H + ‘leak' and/or counterion conductances contributed to the pH difference between two secretory pathway organelles. A pH-sensitive, membrane-permeable fluorescein–biotin was targeted to endoplasmic-reticulum- and Golgi-localized avidin-chimera proteins in HeLa cells. In live, intact cells, ER pH (…

Extent and duration of angiotensin ii antagonistic activity of irbesartan and candesartan cilexetil

2000

Studies of Reversible Hydrogen Binding in Nano- Sized Materials

2015

Experimental review of materials suitable for reversible hydrogen binding in nanoporous and nanosized structures of materials, based on natural zeolite (clinoptilolite) and graphene (exfoliated electrochemically from raw graphite), were analyzed. Characterization of materials with SEM, XRD, EDS and Raman spectroscopy methods and aspects of synthesis of a nanostructured zeolite and a few-layer graphite material was done in this work. It was established from gas analyzer results that hydrogen mass fraction in natural zeolite ranged from 1.1 % to 1.4 %, but in the few-layer graphite material − from 0.39 % to 0.46 %.

Complex miscibility behaviour for polymer blends in flow

1995

Abstract Experimental observations of the effect of shear flow on the miscibility of binary polymer blends are compared to calculations based on a generalized Gibbs energy of mixing Gγ˙. This mixing free energy characterizes the steady state established at shear rateγ˙, as the sum of G z , the equilibrium Gibbs energy and E s , the energy the system stores while flowing.

Phase diagrams of the system tetrahydrofuran/γ-butyrolactone/poly(ether imide) and determination of interaction parameters

1998

Abstract The thermodynamic interactions in the ternary mixture tetrahydrofuran/γ-butyrolactone/poly(ether imide) (THF/γ-BL/PEI) are investigated from 30 to 50°C. This is a membrane-forming system with a high He-selectivity. Cloud point measurements show that the two binary polymer solutions THF/PEI and γ-BL/PEI exhibit miscibility gaps which close towards the centre of the ternary phase diagram where the mixtures become homogeneous (cosolvency). Vapour pressures were determined for the subsystem THF/γ-BL. For the theoretical calculations the Gibbs energy of mixing is formulated according to the Flory-Huggins theory and the interaction parameter χ THF γ-BL calculated from the vapour pressure…

Shear influence on the phase separation of oligomer blends

1994

Shear influences on the phase separation behaviour of four different blends of ethylene glycol/propylene glycol oligomers, exhibiting upper critical solution temperatures, were investigated. Cloud point curves at rest (turbidity measurements) are reported for all systems, spinodal conditions (light scattering) and tie-lines (analysis of the coexisting phases) are given for some examples. Phase diagrams under shear were obtained from rheological data. They demonstrate that the demixing temperatures of systems where both glycols bear OH end-groups are lowered up to ca. 1°C by shear rates of 1000s−1; the critical composition, generalized to the non-equilibrium conditions of flow, is markedly s…

Distance Functions, Clustering Algorithms and Microarray Data Analysis

2010

Distance functions are a fundamental ingredient of classification and clustering procedures, and this holds true also in the particular case of microarray data. In the general data mining and classification literature, functions such as Euclidean distance or Pearson correlation have gained their status of de facto standards thanks to a considerable amount of experimental validation. For microarray data, the issue of which distance function works best has been investigated, but no final conclusion has been reached. The aim of this extended abstract is to shed further light on that issue. Indeed, we present an experimental study, involving several distances, assessing (a) their intrinsic sepa…