Search results for "evaporation"
showing 10 items of 175 documents
Orientation of charged clay nanotubes in evaporating droplet meniscus.
2015
© 2014 Elsevier Inc. During drying, an aqueous suspension of strongly charged halloysite clay nanotubes concentrates at the edge of the droplet ("coffee-ring" effect) which provides alignment of the tubes along the liquid-substrate contact line. First, the surface charge of the nanotubes was enhanced by polyanion adsorption inside of the lumen to compensate for the internal positive charges. This increased the magnitude of the ξ-potential of the tubes from -36 to -81mV and stabilized the colloids. Then, colloidal halloysite was dropped onto the substrate, dried at 65°C and after a concentration of ~0.05mgmL-1 was reached, the alignment of nanotubes occurred starting from the droplet edges. …
Study of the growth of ZnS nanoparticles in water/AOT/n-heptane microemulsions by UV-absorption spectroscopy
1999
Abstract ZnS nanoparticles were synthesized at 25°C using water-containing AOT reversed micelles as nanoreactors and characterized by UV–vis spectroscopy. The time dependence of the spectra emphasizes a slow growing process of the ZnS nanoparticles coupled with a change of their photophysical properties. Both processes are well described by power laws. The nanoparticle size can be controlled by the molar ratio R ( R =[water]/[AOT]), i.e. by the micellar size. The deposits obtained by evaporation of the volatile components of the microemulsions are found to be composed of a surfactant matrix containing ZnS nanoparticles smaller and more stable than that in the corresponding microemulsions.
Hawking radiation correlations in Bose-Einstein condensates using quantum field theory in curved space
2013
The density-density correlation function is computed for the Bogoliubov pseudoparticles created in a Bose-Einstein condensate undergoing a black hole flow. On the basis of the gravitational analogy, the method used relies only on quantum field theory in curved spacetime techniques. A comparison with the results obtained by ab initio full condensed matter calculations is given, confirming the validity of the approximation used, provided the profile of the flow varies smoothly on scales compared to the condensate healing length.
Black hole evaporation in a thermalized final-state projection model
2007
4 pages, 1 figure.-- PACS nrs.: 04.70.Dy; 03.67.-a.-- ISI Article Identifier: 000245333600044.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-th/0611152
Quantum geometry and microscopic black hole entropy
2006
9 pages, 6 figures.-- PACS nrs.: 04.60.Pp, 04.70.Dy.-- ISI Article Identifier: 000242448900013.-- Published online on Nov 28, 2006.
Positive ion extraction across the superfluid-vapor helium interface
2009
The extraction efficiency of positive (219)Rn ions across the superfluid-vapor helium interface above similar to 1.3 K indicates that extraction results from thermal activation across a barrier of about 20 K. Below similar to 1.3 K, the extraction efficiency is constant at about 0.7%. The evaporation of the superfluid surface by second sound pulses has a negative impact on the ion extraction, but not on the ions themselves. It takes 3.2( 6) s at 1.60 K and 15( 6) s at 1.15 K for the extraction process to recover from a disturbed state of yet unknown nature.
Isotope disequilibrium effects: The influence of evaporation and ventilation effects on the carbon and oxygen isotope composition of speleothems – A …
2012
Abstract In order to improve the understanding of variations of speleothem δ18O and δ13C values in the context of palaeoclimate research, it is important to quantify the isotope fractionation processes influencing the δ18O and δ13C values of stalagmites. Here we present an extended version of speleothem stable isotope model that accounts for evaporation and condensation effects during precipitation of calcite. The ISOLUTION-model allows to calculate the effect of evaporation on δ18Ocalcite and δ13Ccalcite values in dependence on relative humidity and wind velocity. Our results reveal that evaporation may have a significant effect on δ18Ocalcite and δ13Ccalcite due to the loss of H2O from th…
Towards Large-Scale Steady-State Enhanced Nuclear Magnetization with In Situ Detection
2021
Signal Amplification By Reversible Exchange (SABRE) boosts NMR signals of various nuclei enabling new applications spanning from magnetic resonance imaging to analytical chemistry and fundamental physics. SABRE is especially well positioned for continuous generation of enhanced magnetization on a large scale, however, several challenges need to be addressed for accomplishing this goal. Specifically, SABRE requires (i) a specialized catalyst capable of reversible H2 activation and (ii) physical transfer of the sample from the point of magnetization generation to the point of detection (e.g., a high-field or a benchtop NMR spectrometer). Moreover, (iii) continuous parahydrogen bubbling accele…
Study of TiO2 nanomembranes obtained by an induction heated MOCVD reactor
2015
Abstract Nanostructures of TiO2 were grown using the metal oxide chemical vapor deposition (MOCVD) technique. The procedure used induction heating on a graphite susceptor. This specific feature and the use of cobalt and ferrocene catalysts resulted in nanomembranes never obtained by common MOCVD reactors. The present study discusses the preparation of TiO2 nanomembranes and the dependence of nanomembrane structure and morphology on growth parameters.
QCD resummation effects in forward J/ψ and very backward jet inclusive production at the LHC
2017
´ We propose and study the inclusive production of a forward J/ψ and a very backward jet at the LHC as an observable to reveal high-energy resummation effects à la BFKL. Our different predictions are based on the various existing mechanisms to describe the production of the J/ψ, namely, NRQCD singlet and octet contributions, and the color evaporation model. © 2017 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). Peer reviewed