Search results for "surface"

Surface Reflectance: An Optical Method for Multiscale Curvature Characterization of Wear on Ceramic–Metal Composites

2020

Surface gradient characterization by light reflectance (SGCLR) is used for the first time for multiscale curvature calculations and discrimination of worn surfaces on six damaged ceramic&ndash

Impact of Land Cover Change Induced by a Fire Event on the Surface Energy Fluxes Derived from Remote Sensing

2015

Forest fires affect the natural cycle of the vegetation, and the structure and functioning of ecosystems. As a consequence of defoliation and vegetation mortality, surface energy flux patterns can suffer variations. Remote sensing techniques together with surface energy balance modeling offer the opportunity to explore these changes. In this paper we focus on a Mediterranean forest ecosystem. A fire event occurred in 2001 in Almodovar del Pinar (Spain) affecting a pine and shrub area. A two-source energy balance approach was applied to a set of Landsat 5-TM and Landsat 7-EMT+ images to estimate the surface fluxes in the area. Three post-fire periods were analyzed, six, seven, nine, and 11 y…

Disclosing of optical properties of metal/dielectric heterostructures by Spectroscopic Ellipsometry enhanced by Surface Plasmon Resonance

2013

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 …

Control of CaCO3 Crystallization by Demixing of Monolayers

2006

In this paper we describe how to template a demixed monolayer into a spatially patterned inorganic replica. For this purpose a new amphiphilic monomer was synthesized which can be polymerized both in solution and in the monolayer of a Langmuir-Blodgett (LB) trough. Since it inhibits the crystallization of CaCO3, it can be used--in combination with stearic acid (nucleation-promotor)--to control CaCO3 crystals formed under the monolayer. Investigations of the two-component monolayer (Langmuir isotherms and AFM measurements of transferred films) show--in the biphasic region--demixing in solid analogue stearic acid domains and the liquid analogue phase of the monomer. Crystallization of CaCO3 s…

Superparamagnetic γ-Fe2O3 nanoparticles with tailored functionality for protein separation

2007

Polymer coated superparamagnetic gamma-Fe(2)O(3) nanoparticles were derivatized with a synthetic double-stranded RNA [poly(IC)], a known allosteric activator of the latent (2-5)A synthetase, to separate a single 35 kDa protein from a crude extract which cross reacted with antibodies raised against the sponge enzyme.

Experimental and theoretical evidence of overcharging of calcium silicate hydrate

2007

International audience; Electrokinetic measurements such as electrophoresis may show an inversion of the effective surface charge of colloidal particle called overcharging. This phenomenon has been studied by various theoretical approaches but up to now very few attempts of confrontation between theory and experiment have been conducted. In this work we report electrophoretic measurements as well as Monte Carlo simulations of the electrokinetic potential for the surface of calcium silicate hydrate (Csingle bondSsingle bondH), which is the major constituent of hydrated cement. In the simulations, the surface charge of Csingle bondSsingle bondH nanoparticles in equilibrium with the ionic solu…

Testing models of dental development in the earliest bony vertebrates, Andreolepis and Lophosteus

2012

Theories on the development and evolution of teeth have long been biased by the fallacy that chondrichthyans reflect the ancestral condition for jawed vertebrates. However, correctly resolving the nature of the primitive vertebrate dentition is challenged by a dearth of evidence on dental development in primitive osteichthyans. Jaw elements from the Silurian–Devonian stem-osteichthyansLophosteusandAndreolepishave been described to bear a dentition arranged in longitudinal rows and vertical files, reminiscent of a pattern of successional development. We tested this inference, using synchrotron radiation X-ray tomographic microscopy (SRXTM) to reveal the pattern of skeletal development preser…

Evaluation of the surface affinity of water in three biochars using fast field cycling NMR relaxometry

2015

Many soil functions depend on the interaction of water with soil. The affinity of water for soils can be altered by applying soil amendments like stone meal, manure, or biochar (a carbonaceous material obtained by pyrolysis of biomasses). In fact, the addition of hydrophobic biochar to soil may increase soil repellency, reduce water-adsorbing capacity, inhibit microbial activity, alter soil filter, buffer, storage, and transformation functions. For this reason, it is of paramount importance to monitor water affinity for biochar surface (also referred to as 'wettability') in order to better address its applications in soil systems. In this study, we propose the use of fast field cycling NMR …

The oxidation state of a protein observed molecole-by-molecule.

2005

We report the observation of the redox state of the blue copper protein azurin on the single-molecule level. The fluorescence of a small fluorophore attached to the protein is modulated by the change in absorption of the copper center via fluorescence resonance energy transfer (FRET). In our model system, the fluorescence label Cy5 was coupled to azurin from Pseudomonas aeruginosa via cysteine K27C. The Cy5 fluorescence was partially quenched by the absorption of the copper center of azurin in its oxidized state. In the reduced state, absorption is negligible, and thus no quenching occurs. We report on single-molecule measurements, both in solution by using fluorescence correlation spectros…