8 research outputs found
Characterising moisture ingress in adhesively bonded joints using nuclear reaction analysis
PIXE multivariate statistics and OSL investigation for the classification and dating of archaeological pottery excavated at Tell Al-Rawda site, Syria
International audienceParticle Induced X-ray Emission (PIXE) technique has been utilised to study 48 Syrian ancient pottery fragments taken from excavations at Tell Al-Rawda site. Eighteen elements (Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Ni, Zn, As, Br, Rb, Sr, Y, and Pb) were determined. The elements concentrations have been processed using two multivariate statistical methods, to classify the pottery where one main group and other two small groups were defined. In addition, four samples from different places on the site were subjected to optically stimulated luminescence (OSL) dating. The average age obtained using a single aliquot regeneration (SAR) protocol was found to be 4350 ± 240 year
Scanning ion microbeam analysis of diffusion in in-mouth drug release polymers
With the aim of characterizing polymer-based drug delivery systems a combination of Scanning MeV 3He microbeam Nuclear Reaction, Backscattering and Particle Induced X-ray Emission (PIXE) techniques has been developed. This, together with gravimetric and UV techniques has been applied to characterize both water infusion and drug effusion for three in-mouth polymer–drug systems. Preliminary results are presented from the exposure of polymers, containing drug at a level of 9% by weight of the dry polymer, to both pure water and a phosphate buffered saline solution at 37°C
Scanning ion microbeam analysis of diffusion in in-mouth drug release polymers
With the aim of characterizing polymer-based drug delivery systems a combination of Scanning MeV 3He microbeam Nuclear Reaction, Backscattering and Particle Induced X-ray Emission (PIXE) techniques has been developed. This, together with gravimetric and UV techniques has been applied to characterize both water infusion and drug effusion for three in-mouth polymer–drug systems. Preliminary results are presented from the exposure of polymers, containing drug at a level of 9% by weight of the dry polymer, to both pure water and a phosphate buffered saline solution at 37°C
In situ water permeation measurement using an external He-3(2+) ion beam
A new approach for water vapour transmission rate (WVTR) measurement is demonstrated that uses an external ion beam. ‘Sandwich’ specimens were prepared comprising two films of the barrier material (PET) surrounding a thin film of hydrophilic poly(ethylene-oxide), “PEO”. Deuterated water (D2O) permeating PET barrier films was trapped by the PEO, and quantified using 3He2+ nuclear reaction analysis and proton detection. WVTR was determined from the rate of D2O accumulation in the PEO layer. This approach may be applied both to poor barrier films with WVTRs of >200 g m−2 day−1, and may extend to films whose barrier properties exceed levels that can be characterised with conventional techniques. Variation in the proton energy distribution provides a means of measuring D2O migration within test samples, and could be used to detect the approach to failure in complex barrier films. In these experiments, D2O migration toward the irradiated face of the sample was attributed to ion beam-induced reactive sites or increased hydrophilicity of the barrier film, and was verified by separate measurements of the D2O content of PET films. Strategies for improving the sensitivity and accuracy of this method for WVTR characterisation towards a lower detection limit 1 μg m−2 day−1 are discussed