Search results for "Dispersion."

Supramolecular self-assembly on the B-Si(111)-(√3x√3) R30° surface: From single molecules to multicomponent networks

2017

Abstract Understanding the physical and chemical processes in which local interactions lead to ordered structures is of particular relevance to the realization of supramolecular architectures on surfaces. While spectacular patterns have been demonstrated on metal surfaces, there have been fewer studies of the spontaneous organization of supramolecular networks on semiconductor surfaces, where the formation of covalent bonds between organics and adatoms usually hamper the diffusion of molecules and their subsequent interactions with each other. However, the saturation of the dangling bonds at a semiconductor surface is known to make them inert and offers a unique way for the engineering of m…

Cosmetotecnia de los dentífricos.Relevancia del comportamiento reológico

2016

RESUMEN: Cosmetotecnia de los dentífricos. Relevancia del comportamiento reológico. Códigos UNESCO: 220499 (reología). 220402 (dispersiones). Los dentífricos se consideran productos semisólidos diseñados para limpiar los dientes y proporcionar un aliento fresco y agradable. Estos productos son una combinación de abrasivos (p.e. hydrated silica), humectantes, agua, surfactantes, agente anticaries (p.e. flúor), espesantes (p.e. cellulose gum, xanthan gum and carrageenan) y aromas, entre otros. Además, deben ser fácilmente extruibles del envase (“squeezing out”), mantener la suficiente rigidez (“stand up”) sobre el cepillo y tener un sabor aceptable para el consumidor. La elaboración de los mi…

Inverse nonlinear design in silicon waveguides

2014

La tecnologia fotònica basada en silici és objecte d'intensa investigació tant al món acadèmic com a la indústria. Un dels seus principals atractius rau en la seua elevada compatibilitat amb tècniques ja desenvolupades per a la integració de circuits electrònics, cosa que podria reduir el seu cost. A més, el silici ofereix una gran diversitat d'efectes no lineals que poden ser aprofitats per processar senyals òptics en xips compactes a velocitats superiors als dispositius electrònics actuals. En particular, l'objectiu d'aquesta tesi ha estat dissenyar una guia integrada en una plataforma híbrida de silici i sílice per generar espectres supercontinus. Aquest projecte presentava diferents rep…

Stretched fibre based dispersion compensating module for ultra high-speed telecommunication systems

2008

International audience; In this work, the potential efficiency of a low-loss, tunable second-and third-order dispersion compensating module based on a stretched optical fibre for ultra high-speed telecommunication systems is analysed. Experimental results at a repetition rate of 640 GHz show that precise dispersion compensation could be achieved in the range of +0.038 ps/nm by means of an 11.3 cm maximum stretching of a 48 m long dispersion compensating.

Practical design rules for single-channel ultra high-speed dense dispersion management telecommunication systems

2009

International audience; In this work, we establish some efficient and practical design rules for the implementation of single-channel ultra-high speed (>160-Gbit/s) telecommunication systems based on dense dispersion management. Moreover, we analyze some of actual implementation issues such as slope compensation scenario, junction losses, polarization mode dispersion and chromatic dispersion fluctuations.

Sul perché le descrizioni dipendono dalle intenzioni progettuali. Possibili letture dei territori della dispersione

2008

Secchi (1996) afferma che descrivere e interpretare sono operazioni altamente selettive che concorrono alla costruzione del progetto. Altresì Vettoretto (!994) ribadisce la non neutralità di tali operazioni che rivelano, invece, le "intenzioni" progettuali. Il saggio raccoglie alcune descrizioni/interpretazioni elaborate sulla dispersione insediativa che mettono in luce i differenti approcci progettuali degli autori.

Vanadium Carbide Dissolution during Austenitisation of a Model Microalloyed FeCV Steel

2005

High performance commercial micro alloyed steels contain elements such as vanadium, which leads to a fine dispersion of vanadium carbide precipitates. The precipitation state, in terms of volume fraction and size distribution, plays a significant role in final mechanical properties of the material. Different austenitisation heat treatments were performed on a model ternary alloy FeCV. Precipitation states were characterised combining different experimental techniques. TEM was used to identify the chemical composition of observed precipitates. ICP mass spectroscopy was performed to measure the volume fraction of precipitates. The size distribution was studied by SEM. Results are characterist…

Technology Diffusion, Worker Mobility and the Returns to Skill

2015

In this paper I illustrate how the diffusion across firms of a skill-neutral technology leads to a skill-biased impact on the economy. The model identifies (i) differences in inter-firm mobility between skill groups, (ii) productivity dispersion across firms within industries, and (iii) differences in wages between small and large firms as key determinants of the skill premium. Calibrated to match differences in inter-firm mobility between skill groups and rising productivity dispersion across firms, the model ascribes one-third of the sharp increase in the skill premium in U.S. manufacturing from 1977 to 1997 to skill-neutral technical progress and the technology diffusion process itself. …

Interpreting and modelling field data for wastewater dispersion into sea through dimensional analysis

2008

Assessment of protection treatments for carbonatic stone using nanocomposite coatings

2020

In this paper the effect of the application of four kinds of polymer dispersions containing nanoparticles, used as protectives, on two type of carbonatic lithotypes, White Noto and Comiso stone, is reported. The study was conducted by analysing the contribution of each component of the system. After the structural characterization of the coating itself, the performance of those colloidal systems has been studied upon application on the calcarenites, preferring non-invasive techniques and microdestructive techniques. Effect of the nanoparticles presence on hydrorepellency and roughness of the stone surface and on chromatic changes has also been considered. The tests conducted have proven tha…