Results 251 to 260 of about 41,464 (303)

Hydrogen permeation barrier – Recognition of defective barrier film from transient permeation rate

International Journal of Hydrogen Energy, 2011
Hydrogen permeation barrier films often exhibit lower efficiency than anticipated. The cause could be defects in the barrier film, high permeability of the defect-free (dense) barrier film, or a combination of both. It is very difficult to point at and quantify the responsible mechanism since the defects can be of submicrometer dimensions and very ...
Bojan Zajec
exaly   +2 more sources

Analysis of Nanoporosity in Moisture Permeation Barrier Layers by Electrochemical Impedance Spectroscopy

ACS Applied Materials & Interfaces, 2015
Water permeation in inorganic moisture permeation barriers occurs through macroscale defects/pinholes and nanopores, the latter with size approaching the water kinetic diameter (0.27 nm). Both permeation paths can be identified by the calcium test, i.e.,
Alberto Perrotta, Santiago J Garcia, Jasper J Michels   +2 more
exaly   +2 more sources

Permeation of Gas Barrier Layers

Journal of Thermal Insulation and Building Envelopes, 1995
The thermal conductivity ageing of a polyurethane foam can be sig nificantly influenced by the presence of a diffusion barrier, i.e., a bitumen facer. Such a bitumen facer attached completely to the surface of a PUR slab is generally con sidered a tool to slow down the exchange of cell gas with the environment.
K.H. Brodt, R.R.H. Brood, G.C.J. Bart
openaire   +1 more source

Models for predicting blood–brain barrier permeation

Drug Discovery Today, 2011
The endothelial blood-brain barrier (BBB) ensures an optimal environment for proper neural function in vertebrates; however, it also creates a major obstacle for the medical treatment of brain diseases. Despite significant progress in the development of various in vitro and in silico models for predicting BBB permeation, many challenges remain and, so ...
Nielsen, Peter Aadal, Andersson, Olga, Hansen, Steen Honore', Simonsen, Klaus Bæk, Andersson, Gunnar   +4 more
openaire   +3 more sources

Polyurethane Adhesive Nanocomposites as Gas Permeation Barrier

Macromolecules, 2003
Adhesive nanocomposites of organically modified montmorillonite (OM) and polyurethane have been synthesized and their permeability to oxygen and water vapor has been measured. The gas permeation through the composites was correlated to the volume fraction of the impermeable inorganic part of the OM.
M. A. Osman, V. Mittal, MORBIDELLI, MASSIMO, U. W. Suter   +3 more
openaire   +1 more source

Urapidil permeates the intact blood-brain barrier

Intensive Care Medicine, 1994
To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations.Open, single-dose study.Post-surgery following neurosurgical removal of the hypophysis (n = 5) or aneurysm clipping (n = 1).6 patients, aged 32-71 years, with intact ...
G, Castor, U, Schmidt
openaire   +2 more sources

Hydrogen permeation through tritium permeation barrier in Pb–17Li

Fusion Engineering and Design, 2001
One of the main problems in the development of water cooled lithium lead (WCLL) DEMO fusion reactor is the reduction of the tritium permeation from the Pb–17Li, or the plasma, into the cooling water. The control of tritium losses is an important issue in fusion technology because of its safety and operational implications.
A. Aiello, G. Benamati, M. Chini, C. Fazio, E. Serra, Z. Yao   +5 more
openaire   +1 more source

Overcoming the Skin Permeation Barrier: Challenges and Opportunities

Current Pharmaceutical Design, 2015
Stratum corneum (SC), the outermost layer of the skin, constitutes an excellent protective physiological barrier, and is the main challenge in transdermal drug delivery. Many approaches have been used to enhance the penetration of drugs through this layer, covering passive and active methods or the combination of both.
Carla, Vitorino, Joao, Sousa, Alberto, Pais   +2 more
openaire   +2 more sources

The human nail – Barrier characterisation and permeation enhancement

International Journal of Pharmaceutics, 2012
The human nail remains one of the most challenging membranes for formulation scientists to target and for clinicians to heal. Its formidable barrier properties are the primary reason that oral therapy remains the primary approach to manage ungual infections.
Kenneth A, Walters, Haydar M, Abdalghafor, Majella E, Lane   +2 more
openaire   +2 more sources