Search results for "surface"
showing 10 items of 9345 documents
An Atom-Economical Approach to Functionalized Single-Walled Carbon Nanotubes: Reaction with Disulfides
2013
Owing to their unique structure, thermal stability, and mechanical and electronic properties, single-walled carbon nanotubes (SWCNTs) have been a subject of continuous and intense interest. However, various applications in many fields, such as molecular electronics, solar cells, and nanomedicine, often require the development of reproducible protocols for the chemical modification of SWCNTs. In fact, one of the main drawbacks of the use of SWCNTs is their tendency to aggregate and intrinsic poor solubility, which prevent their manipulation and limit their potential. To date, several methods have been described for the chemical functionalization of SWCNTs; however, new versatile and reliable…
Changes in surface stress, morphology and chemical composition of silica and silicon nitride surfaces during the etching by gaseous HF acid
2007
International audience; HF acid attack of SiO2 and Si3N4 substrates is analyzed to improve the sensitivity of a sensor based on inicrocantilever. Ex situ analysis of the etching using XPS, SIMS and AFM show significant changes in the anisotropy and the rate of the etching of the oxides on SiO2 and Si3N4 surface. Those differences influence the kinetic evolution of the plastic bending deflection of the cantilever coated with SiO2 and Si3N4 layer, respectively. The linear dependence between the HF concentration and the Si3N4 cantilever bending corresponds to a deep attack of the layer whereas the nonlinear behavior observed for SiO2 layer can be explained by a combination of deep and lateral …
Carbon Dots Dispersed on Graphene/SiO2/Si: A Morphological Study
2019
Low-dimensional carbon materials occupy a relevant role in the field of nanotechnology. Herein, the authors report a study conducted by atomic force microscopy and Raman spectroscopy on the deposition of carbon dots onto graphene surfaces. The study aims at understanding if and how the morphology and the microstructure of chemical vapor deposited graphene on Si/SiO2 may change due to the interaction with the carbon dots. Potential alteration in the graphene's electrical properties might be detrimental for optoelectronic applications. The deposition of carbon dots dispersed in water and ethanol solvents are explored to investigate the effect of solvents with different fluidic properties. The…
Analistas simbólicos, jerarquía urbana y atracción de talento en las ciudades mundiales españolas (2005-2019): un análisis a partir de la EPA
2021
Este trabajo utiliza los microdatos de la Encuesta de población activa del INE entre 2005 y 2019 para analizar el nivel de competencias de la población ocupada, los procesos de cualificación del mercado de trabajo de las ciudades mundiales españolas (Madrid, Barcelona, Valencia, Sevilla y Bilbao) y el papel que están teniendo las migraciones de profesionales y técnicos altamente cualificados como reflejo de su capacidad diferencial para atraer talento externo. Siguiendo el marco conceptual propuesto por Allen J. Scott de creciente polarización de los mercados de trabajo metropolitanos entre una clase de «analistas simbólicos» de alta cualificación y una «subclase de servicios», se considera…
Coupling two radar backscattering models to assess soil roughness and surface water content at farm scale
2013
Remote sensing techniques are useful for agro-hydrological monitoring at the farm scale because the availability of spatially and temporally distributed data improves agricultural models for irrigation and crop yield optimization under water scarcity conditions. This research focuses on the surface water content retrieval using active microwave data. Two semi-empirical models were chosen as these showed the best performances in simulating cross and co-polarized backscatter. Thus, these models were coupled to obtain reliable assessments of both soil water content and soil roughness. The use of the coupled model enables one to avoid using roughness measured in situ. Remote sensing images and …
Influence of anodizing surface treatment on the aging behavior in salt-fog environment of aluminum alloy 5083 to fiber reinforced composites adhesive…
2021
The present work aims to evaluate how an innovative and eco-friendly anodizing process with tartaric-sulfuric acid (TSA) bath and a pore widening in an aqueous solution of NaOH 0.1 M can improve the durability in marine environment of co-cured adhesive joints between an aluminum alloy (AA 5083) and fiber (i.e., glass or basalt)-reinforced composite substrates. The aging was carried out by exposing samples to salt-fog spray conditions (5 wt.% NaCl) for 30, 60 and 90 days in a climate chamber, in accordance with ASTM B117. In order to get further insights on the aging behaviour of bonded joints, neat matrix was also exposed to the same environment for 60 days. Quasi-static mechanical tests an…
Nitrogen Adsorption on Graphene Sponges Synthesized by Annealing a Mixture of Nickel and Carbon Powders
2017
The present research has been supported by the National Research Programme for 2014–2017 “Multifunctional Materials and Composites, Photonics and Nanotechnologies”.
Yeast Killer Toxin-Like Candidacidal Ab6 Antibodies Elicited through the Manipulation of the Idiotypic Cascade
2014
A mouse anti-anti-anti-idiotypic (Id) IgM monoclonal antibody (mAb K20, Ab4), functionally mimicking a Wyckerhamomyces anomalus (Pichia anomala) killer toxin (KT) characterized by fungicidal activity against yeasts presenting specific cell wall receptors (KTR) mainly constituted by β-1,3-glucan, was produced from animals presenting anti-KT Abs (Ab3) following immunization with a rat IgM anti-Id KT-like mAb (mAb K10, Ab2). MAb K10 was produced by immunization with a KT-neutralizing mAb (mAb KT4, Ab1) bearing the internal image of KTR. MAb K20, likewise mAb K10, proved to be fungicidal in vitro against KT-sensitive Candida albicans cells, an activity neutralized by mAb KT4, and was capable of…
Innovative and Applied Research in Biology: Proceedings, Vol.1
2019
Projekti: ZD2016/AZ81 & ZD2016/AZ107
Gulf of Maine shells reveal changes in seawater temperature seasonality during the Medieval Climate Anomaly and the Little Ice Age
2011
article i nfo In this study, we use subannually resolved oxygen isotope values of fossil (dead-collected) and modern (live- caught) bivalve shells (Arctica islandica L.) from the northwestern Atlantic (Gulf of Maine, USA) to reconstruct past seasonal changes in seawater temperature. Our results indicate decreased seasonal temperature amplitude of about 1.6 °C (or ∼21%) during Medieval times (ca. AD 1033-1062) compared to shells from the early Little Ice Age (ca. AD 1321-1391) and during the late 19th century (AD 1864-1886). Additionally, seasonal oxygen isotope data suggest that summers were cooler and winters were warmer in the Gulf of Maine during the 11th century compared to summers and …