Search results for "Diffusion"
showing 10 items of 1615 documents
STUDIO "IN VITRO" SULLA CAPACITA' DI DIFFUSIONE DELLA GUTTAPERCA UTILIZZANDO TRE DIVERSI SISTEMI DI OTTURAZIONE CANALARE A CALDO
2008
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
2016
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad …
Influence of temperature on mass transfer in an incomplete trapping single hollow fibre supported liquid membrane extraction of triazole fungicides.
2008
The influence of temperature in a single hollow fibre supported liquid membrane extraction of triazole fungicides with a stagnant acceptor phase was investigated. The mass transfer parameters such as diffusion coefficient, flux and apparent viscosity were determined at temperature ranging from 278 K to 313 K. Increase in temperature led to an increase in diffusion coefficient and flux. The apparent viscosity also decreased with an increase in temperature. The degree of trapping in the acceptor phase influenced the mass transfer at higher temperature. At lower temperature, the transport of analytes from the donor solution through the donor-membrane interface and through the membrane mainly a…
Modeling and Design of Membrane Integrated Processes for HCl and Metals Recovery from Pickling Solutions
2018
Hydrochloric acid pickling is a common practice in steel manufacturing industry. During the process, acid is consumed to dissolve surface oxides and metals are accumulated in the solution. This fact leads to a process efficiency decrease. Continuous regeneration of pickling solutions enhances process rate and performance, but also minimises the highly expensive and environmentally risky wastewater disposal. The recovery of valuable substances (e.g. acid and metals) can be accomplished by coupling diffusion dialysis (DD) and membrane distillation (MD) technologies. In the present work, a steady state process simulator for the integrated process has been developed. The aim is to analyze and p…
IT-supported international outsourcing of software production
2002
A new application for nickel foam in alkaline fuel cells
2009
The use of nickel foam as an electrode substrate in alkaline fuel cells (AFCs) has been investigated for bi-polar cells incorporating an electrically conducting gas diffusion layer. This contribution focuses on the cathode, and draws comparisons between nickel foam and nickel mesh substrates. One of the principal electrocatalysts for the cathodic reduction of oxygen is silver, so an improvement in electrochemical performance was obtained by electroplating the nickel foam with silver. The electrodeposition process was optimised to maximise electrochemical performance with a minimum of silver deposited. Nickel foam, which is less expensive than the usual nickel mesh, appears to be a good subs…
Domain formation in monolayers
1995
For phospholipids at the air/water interface we demonstrate that molecular chirality in some, but not in all, cases influences the domain shapes. In other cases chirality in the head group region can cause a chiral structure considering the tail arrangement. This indicates head group ordering. Minute changes of the molecular structure may change domain morphology from circular to dendritic. This can be related to slight changes of the lattice structure. In case of a dendritic domain the chains are more tilted, the deviation from hexagonal symmetry is more pronounced, and hence the lattice anisotropy is larger. This can be understood also in view of recent simulations considering diffusion-l…
Synthesis and preliminary in vivo evaluation of well-dispersed biomimetic nanocrystalline apatites labeled with positron emission tomographic imaging…
2015
In recent years, biomimetic synthetic apatite nanoparticles (AP-NPs), having chemical similarity with the mineral phase of bone, have attracted a great interest in nanomedicine as potential drug carriers. To evaluate the therapeutic perspectives of AP-NPs through the mechanisms of action and organs they interact with, the noninvasive monitoring of their in vivo behavior is of paramount importance. To this aim, here the feasibility to radiolabel AP-NPs ("naked" and surface-modified with citrate to reduce their aggregation) with two positron emission tomographic (PET) imaging agents ([F-18]NaF and Ga-68-NO(2)AP(BP)) was investigated. [F-18]NaF was used for the direct incorporation of the radi…
Influence of oxide substrates on monolayer graphene doping process by thermal treatments in oxygen
2019
Abstract The structural and the electronic properties of monolayer graphene made by chemical vapor deposition and transferred on various oxide substrates ( SiO 2 , Al 2 O 3 , and HfO 2 ) are investigated by Raman Spectroscopy and Atomic Force Microscopy in order to highlight the influence of the substrate on the features of p-doping obtained by O 2 thermal treatments. By varing the treatment temperature up to 400 °C, the distribution of the reaction sites of the substrates is evaluated. Their total concentration and the consequent highest doping available is determined and it is shown that this latter is linked to the water affinity of the substrate. Finally, by varing the exposure time to …
Formation and characterization of oxidic and metallic Fe/Ni multilayers prepared from Langmuir-Blodgett films
1994
Oxidic and metallic iron, nickel, and mixed iron/nickel mono- and multilayers were prepared by some treatments of iron- and nickel-containing Langmuir-Blodgett films. The layers were characterized by several surface-sensitive methods. Interactions between the iron and the nickel could be observed. The results are different to those obtained from disordered bulk alloys and from simple diffusion calculations.