Search results for "BEC"

Semiflexible Polymers in Spherical Confinement: Bipolar Orientational Order Versus Tennis Ball States

2017

Densely packed semiflexible polymers with contour length L confined in spheres with radius R of the same order as L cannot exhibit uniform nematic order. Depending on the chain stiffness (which we vary over a wide range), highly distorted structures form with topological defects on the sphere surface. These structures are completely different from previously observed ones of very long chains winding around the inner surface of spheres and from nematic droplets. At high densities, a thin shell of polymers close to the sphere surface exhibits a tennis ball texture due to the confinement-induced gradual bending of polymer bonds. In contrast, when the contour length of the chains is significant…

Droplets pinned at chemically inhomogenous substrates: A simulation study of the two-dimensional Ising case

2016

As a simplified model of a liquid nanostripe adsorbed on a chemically structured substrate surface, a two-dimensional Ising system with two boundaries at which surface fields act is studied. At the upper boundary, the surface field is uniformly negative, while at the lower boundary (a distance L apart), the surface field is negative only outside a range of extension b, where a positive surface stabilizes a droplet of the phase with positive magnetization for temperatures T exceeding the critical temperature Tw of the wetting transition of this model. We investigate the local order parameter profiles across the droplet, both in the directions parallel and perpendicular to the substrate, vary…

Polymeric drug delivery micelle-like nanocarriers for pulmonary administration of beclomethasone dipropionate

2017

In this paper, the potential of novel polymeric micelles as drug delivery systems for Beclomethasone Dipropionate (BDP) administration into the lung is investigated. These nanostructures are obtained starting from α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA), which was subsequently functionalized with O-(2-aminoethyl)-O’-methylpolyethylenglycole (PEG2000), ethylenediamine (EDA) and lipoic acid (LA), obtaining PHEA-PEG2000-EDA-LA graft copolymer. Empty and drug-loaded micelles possess adequate chemical-physical characteristics for pulmonary administration such as spherical shape, slightly positive surface charge and mean size of about 200 nm. Besides, BDP-loaded micelles, obtained …

Evaluation of the MOD16A2 evapotranspiration product in an agricultural area of Argentina, the Pampas region

2021

The Pampas Region is a big plain of approximately 520,000 km2 in Argentina. It is essential to estimate evapotranspiration (ET) in this region since the primary productivity is directly linked to water availability. Information provided by satellite missions allows monitoring the spatial and temporal variability of ET. In the current study, we evaluated the version 006 of MOD16A2 product (MOD16A2.006) of Potential Evapotranspiration (ETp) and Actual Evapotranspiration (ETa) in Argentinian Pampas Region (APR). MOD16A2.006 product was compared with Crop Evapotranspiration (ETc), calculated with local measurements from the Oficina de Riesgo Agropecuario (ORA), and Crop Coefficient (Kc) data (f…

Old-timers and newcomers: The shrews and heterosoricids from the Ribesalbes-Alcora Basin (East of Spain)

2019

The zone of Araia d’Alcora in the Ribesalbes-Alcora Basin (Spain, early Miocene, biozone C, MN 4) yielded a relatively rich assemblage of shrews for an Iberian site, composed by Oligosorex thauensis, cf. Soricella discrepans, Paenelimnoecus micromorphus and Heterosorex neumayrianus. The fossils of O. thauensis, the most abundant taxon, significantly increase our knowledge regarding the morphology of the species. It signals the last known occurrence of this shrew and extending its record to a MN4 site. This species is competing with other shrews in the studied sites. Paenelimnoecus micromorphus is recorded for the first time in the Iberian Peninsula. Soricella discrepans is a typical species…

Towards a complete phylogeny of African Melastomateae : systematics of Dissotis and allies (Melastomataceae)

2020

Late Cenozoic brittle deformation in the Southern Patagonian Andes: Record of plate coupling/decoupling during variable subduction?

2018

The Andes of southern Patagonia experienced a Miocene shift towards faster and higher angle subduction followed by the approach and collision of the Chile oceanic ridge. We present a kinematic study characterizing palaeostress fields computed from brittle tectonics to better constrain upper crustal deformation during this complex scenario. Although previous studies already suggested variable kinematics, it is striking that in a long-lasting subduction environment, the computed palaeostress tensors are mostly strike-slip (55%), while 35% are extensional, and only 10% compressive which are concentrated along a main frontal thrust. Cross-cutting relationships and synsedimentary deformation ind…

Characterization of V-doped SnO2 nanoparticles at ambient and high pressures

2018

Nanoparticles of V-doped SnO2 with stoichiometry Sn1-xO2Vx (x = 0.05, 0.075, 0.125) have been synthesized by a co-precipitation method. Their structural, vibrational, and nuclear properties have been characterized by x-ray Diffraction, Transmission Electron Microscopy, Energy Dispersive x-ray Spectroscopy, Raman Spectroscopy, and Mössbauer Spectroscopy (with 119Sn probe) at ambient pressure. We also performed high-pressure synchrotron x-ray diffraction experiments. The structural behaviour was studied up to ∼10 GPa under quasi-hydrostatic conditions. It has been found that tin dioxide nanoparticles with V are more compressible than un-doped tin dioxide nanoparticles. Fil: Ferrari, S. Consej…

Thermal potential of ion-exchange membranes and its application to thermoelectric power generation

2016

The low efficiency and high price of thermoelectric semiconductors has generated interest in unconventional forms of thermoelectric materials. In this article, ionic thermoelectricity has been studied with commercial ion-exchange membranes for different aqueous 1:1 electrolytes. The theory of thermal membrane potential has been derived taking into account the ionic heats of transport, the non-isothermal Donnan potentials, the temperature polarization, and the thermally-induced concentration polarization of the electrolyte. Also the generated thermoelectric power has been experimentally studied. The experiments show good agreement with the theory, and suggest ways for systematic improvement …

Exploration of new post-secondary mathematics teachers' experiences: preliminary results of a narrative inquiry

2018

International audience; This paper reports on a pilot study that has taken place during the winter semester of 2017, for a larger project whose goal is to understand the process of becoming a mathematics teacher at post-secondary level. With very few information from the literature on this process at this specific level, this pilot study acts as an exploration of the issues and reality the new teachers face. To do so, we conducted a narrative inquiry with three new post-secondary mathematics teachers who were interviewed on a regular basis during a semester. Those interviews provided an insight into the new teachers' experiences by pointing out themes that are relevant to them. We also came…