Search results for "aggregate"

Aggregation in aqueous media of tri-block copolymers tuned by the molecular selectivity of cyclodextrins

2009

The water + cyclodextrin + poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) mixtures have been investigated to explore the temperature effect on the aggregation of the copolymer in the presence of cyclodextrins (CDs). The CDs with different cavity sizes were chosen because they may include either the hydrophilic poly(ethylene oxides) block or both kinds of blocks. The differential scanning calorimetry and viscosity experiments straightforwardly evidenced that the critical micellar temperature is shifted to larger values by adding a CD which is able to include the middle poly(propylene oxide) block while it is not influenced by the presence of CD which is selective to the poly…

Cementing agents involved in the macro- and microaggregation of a Mediterranean shrubland soil under laboratory heating

2014

The heating effect on aggregation and cementing agents of a Mediterranean soil was studied in two fractions (macro- and microaggregates) in different environments: under Quercus coccifera soil (UQ), under Rosmarinus officinalis soil (UR) and between plants or bare soil (BS). Samples were heated under laboratory conditions at different temperatures (220, 380, 500, 750 and 1000. °C) to establish their effects on the studied soil properties by comparison with unheated control samples (25. °C). Increasing temperature treatments caused significant changes in most soil variables. In both soil fractions, the presence of vegetation contributed to increase of the soil organic matter (SOM) content, w…

Electrospray ion mobility mass spectrometry of positively charged sodium bis[2-ethythexyl)sulfosuccinate aggregates.

2014

Collision cross-sections (CCS) of positively singly and multiply charged aggregates of the surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) in the gas phase have been measured by quadrupole ion mobility time-of-flight mass spectrometry. Calibration of the observed drift times to the CCS of the AOTNa non-covalent aggregates was achieved by collecting, under the same experimental conditions, the drift times of a range of singly and multiply charged polyalanine peptides whose CCS had been obtained by conventional ion mobility spectrometry. Together with an obvious increase of the aggregate cross-section with the aggregation number, it was found that the aggregate cross-section increa…

A New Structural Motif for an Enantiomerically Pure Metallosupramolecular Pd4L8Aggregate by Anion Templating

2014

An enantiomerically pure BINOL-based bis(3-pyridyl) ligand 1 assembles into a homochiral [Pd4(1)8] complex upon coordination to tetravalent PdII ions. The formation of this aggregate is templated by two tetrafluoroborate counterions that are encapsulated in two peripheral cavities. The resulting structure is a new structural motif for this kind of metallosupramolecular assemblies that arranges the palladium ions in a distorted tetrahedral fashion and forces ligand 1 to adopt two different conformations. Both phenomena are unique and cause an overall three-dimensional structure that has another confined, chiral, and hydrophilic central cavity.

Inside Back Cover: N ‐Annulated Perylene Bisimides to Bias the Differentiation of Metastable Supramolecular Assemblies into J‐ and H‐Aggregates (Ange…

2020

Discretionary Fiscal Policies over the Cycle: New Evidence Based on the ESCB Disaggregated Approach

2012

This paper explores how discretionary fiscal policies on the revenue side of the government budget have reacted to economic fluctuations in European Union countries. For this purpose, it uses data on legislated revenue changes and structural indicators provided twice per year by National Central Banks of European Union countries in the ESCB framework for analysing fiscal policy. The analysis is based on the estimation of fiscal policy rules linking these measures of legislated fiscal policy changes to the output gap and other control variables. Then, baseline results are compared with regression estimates where variations of cyclically-adjusted indicators are used as proxy for discretionary…

Self-assembly of a fluorescent diimidazolium naphthalene diimide salt: the effect of increasing alkyl chain length

Alkyl chain length effect on the self assembly of diimidazolium naphthalene diimide salts

EMERGING PROPERTIES IN POPULATION DYNAMICS WITH DIFFERENT TIME SCALES

1995

The aim of this work is to show that at the population level, emerging properties may occur as a result of the coupling between the fast micro-dynamics and the slow macrodynamics. We studied a prey-predator system with different time scales in a heterogeneous environment. A fast time scale is associated to the migration process on spatial patches and a slow time scale is associated to the growth and the interactions between the species. Preys go on the spatial patches on which some resources are located and can be caught by the predators on them. The efficiency of the predators to catch preys is patch-dependent. Preys can be more easily caught on some spatial patches than others. Perturbat…

The Level of Mortality in Insured Populations

2018

In the actuarial field, life tables are used in reserving and pricing processes. They are commonly built from aggregate data and incorporate margins as a prudent measure to ensure the insurance company’s viability. Solvency II requires insurance companies to calculate technical provisions using best-estimate assumptions for future experience (mortality, expenses, lapses, etc) to separate (i) the risk-free component from (ii) adverse deviation of claims. Nowadays, however, the methods used by insurance companies (in most countries, included Spain) do not guarantee that these components can be separated. Many companies build their own tables from general insured population life tables, assumi…