Search results for "Homogeneous"
showing 10 items of 718 documents
Selective photooxidation of ortho-substituted benzyl alcohols and the catalytic role of ortho-methoxybenzaldehyde
2016
It has been recently reported by Palmisano et al. (2015) [1] that the oxidation of 2-methoxybenzyl alcohol (2-MBA) to 2-methoxybenzaldehyde (2-MBAD) proceeds in water under near-UV light with an unexpected catalytic effect of 2-MBAD. In order to investigate the catalytic role of aldehyde in photolytic oxidation of ortho-substituted benzyl alcohols (OSBAs), reactivity runs were carried out with 2-methylbenzyl alcohol (2-MeBA), 2-nitrobenzyl alcohol (2-NBA), 2-hydroxybenzyl alcohol (2-HBA) and 2-chlorobenzyl alcohol (2-CIBA) in the absence and in the presence of their corresponding aldehyde. None of those alcohols showed a measurable oxidation rate even in the presence of their aldehydes but …
Hydroformylation of 1-Octene in Supercritical Carbon Dioxide: Can Alkylation of Arylphosphines with tertButyl Groups Lead to Soluble and Active Catal…
2008
Abstract The possibility of increasing the solubility and activity of rhodium catalysts in the hydroformylation of 1-octene in supercritical carbon dioxide (scCO2) by attachment of tertbutyl (tBu) groups to the triarylphosphine ligand was investigated. The solubility of the parent and monoalkylated ligands in a mixture of gaseous components (CO2/CO/H2) was evaluated by visual observation in a view cell. In the case of triphenylphosphine, introduction of one tertbutyl group does not seem to affect the solubility of the phosphine. When the behaviour of (diphenyl)biphenylphosphine and (para-tertbutyldiphenyl)biphenylphosphine was compared a clear solubilising effect of the tBu group was observ…
Wavefront invasion for a chemotaxis model of Multiple Sclerosis
2016
In this work we study wavefront propagation for a chemotaxis reaction-diffusion system describing the demyelination in Multiple Sclerosis. Through a weakly non linear analysis, we obtain the Ginzburg–Landau equation governing the evolution of the amplitude of the pattern. We validate the analytical findings through numerical simulations. We show the existence of traveling wavefronts connecting two different steady solutions of the equations. The proposed model reproduces the progression of the disease as a wave: for values of the chemotactic parameter below threshold, the wave leaves behind a homogeneous plaque of apoptotic oligodendrocytes. For values of the chemotactic coefficient above t…
Cardinal Invariants for the $G_\delta$ topology
2017
We prove upper bounds for the spread, the Lindel\"of number and the weak Lindel\"of number of the $G_\delta$-topology on a topological space and apply a few of our bounds to give a short proof to a recent result of Juh\'asz and van Mill regarding the cardinality of a $\sigma$-countably tight homogeneous compactum.
Disorder-induced single-mode transmission.
2017
Localized states trap waves propagating in a disordered potential and play a crucial role in Anderson localization, which is the absence of diffusion due to disorder. Some localized states are barely coupled with neighbours because of differences in wavelength or small spatial overlap, thus preventing energy leakage to the surroundings. This is the same degree of isolation found in the homogeneous core of a single-mode optical fibre. Here we show that localized states of a disordered optical fibre are single mode: the transmission channels possess a high degree of resilience to perturbation and invariance with respect to the launch conditions. Our experimental approach allows identification…
Karyotypic diversity among Blastocystis hominis isolates
1997
Fifteen Blastocystis hominis strains, 13 axenic and 2 monoxenic, have been included in the present study. The chromosomal pattern was analyzed by the contour-clamped homogeneous electric-field (CHEF) system. The number of chromosomes detected ranged between 9 and 13, with sizes from 2200 kbp to 260 kbp. Eleven karyotypic profiles, with a common pattern constituted by 8 chromosomes of 2200, 1280, 890, 840, 700, 650, 540 and 260 kbp, were observed. The Jaccard index demonstrated that the similarity between isolates ranged from 0.5714 to 1. The different isolates were clustered in 3 karyotypes (A: 8 isolates; B: 6 isolates and C: 1 isolate). All isolates grouped in karyotype A presented a char…
Localization of amplified CAD genes on rearranged chromosomes of Chinese hamster cells
2012
Chinese hamster cell lines carrying an amplified CAD region were selected from V79,B7 cells by their resistance to N-phosphonacetyl-L-aspartate (PALA). In one of the selected cell lines, SP PALA (inf1) (supR) L, an acrocentric chromosome with abnormally elongated q arms was identified as a marker for the PALA-resistant phenotype. The marker chromosome carried a homogeneously staining region close to a telomeric nucleolar organizer region. In the same region, localization of amplified CAD sequences was demonstrated by in situ hybridization. The marker chromosome was found to undergo extensive rearrangements. In particular, dicentric chromosomes, occurring with an unusually high incidence, we…
Non-equivariant cylindrical contact homology
2013
It was pointed out by Eliashberg in his ICM 2006 plenary talk that the integrable systems of rational Gromov-Witten theory very naturally appear in the rich algebraic formalism of symplectic field theory (SFT). Carefully generalizing the definition of gravitational descendants from Gromov-Witten theory to SFT, one can assign to every contact manifold a Hamiltonian system with symmetries on SFT homology and the question of its integrability arises. While we have shown how the well-known string, dilaton and divisor equations translate from Gromov-Witten theory to SFT, the next step is to show how genus-zero topological recursion translates to SFT. Compatible with the example of SFT of closed …
Centres and peripheries in Finland: Granger causality tests using panel data
2009
Abstract Despite their importance from a policy point of view, empirical studies on the effects of growth centres in their regions are rare. This paper analyses mutual relationships between growth processes in centres and their surrounding hinterlands in 19 Finnish regions. Annual population data from the period 1970–2004 are used. A novel testing procedure based on an extension of the Granger causality definition in a panel data context is applied. Heterogeneity between regions is allowed. Both the homogeneous non-causality hypothesis and the homogeneous causality hypothesis are rejected. Causal processes prove to be heterogeneous. Causality from centres to peripheries is found for nine re…
Quality management in patients associations. Diagnosis in the Spanish Federation of Cystic Fibrosis
2020
La Federación Española de Fibrosis Quística tiene como misión agrupar a las Asociaciones de Fibrosis Quística para mejorar la calidad de vida de las personas con Fibrosis Quística y sus familias. El despliegue de este movimiento en los últimos 20 años no ha sido igual en todas las asociaciones que lo componen. Este artículo, expone el diagnóstico de la cuestión. Con una metodología cuantitativa y cualitativa, se ha triangulando la información procedente de: análisis documental, entrevistas semiestructuradas y encuestas. Los resultados obtenidos plantean la gestión con calidad como elemento favorecedor del fortalecimiento asociativo y la figura del profesional de trabajo social como impulsor…