Search results for "fusion"
showing 10 items of 4513 documents
Introduction into the study of translational diffusion by laser techniques
1988
Breve description de la technique du reseau holographique pour mesurer les coefficients de diffusion de traceurs dans des polymeres et de la technique de spectrometrie de correlation de photon pour la mesure des coefficients de diffusions mutuelle dans des melanges de polymeres
Controlled loading and release of beta-lactoglobulin in calcium-polygalacturonate hydrogels
2020
International audience; We show here how the structure of polygalacturonate (polyGalA) hydrogels cross-linked by Ca2+ cations via external gelation controls the loading and the release rate of betalactoglobulin (BLG), a globular protein. Hydrogels prepared from a polyGalA/BLG solution are found similar to those obtained from a polyGalA solution in our previous study (Maire du Poset, et al. Biomacromolecules 2019, 20(7), 2864-2872): they exhibit similar transparencies and gradients of mechanical properties and polyGalA concentration. The nominal BLG/polyGalA ratio of the mixtures is almost recovered within the whole mixed hydrogel despite such strong concentration gradients, except in the pa…
Diffusion in concentrated colloidal suspensions and glasses
1998
The well established analogy between colloidal suspensions and atomic fluids has been extended to the glass transition problem in the past few years. Colloids have become the ideal test case for checking glass transition theories; this was due to the possibility of modeling hard spheres with colloidal dispersions. Significant progress has also been made in instrumentation, especially in the development of light-scattering techniques allowing moderately turbid and nonergodic samples to be analyzed. Mode coupling theory has become a paradigm not only for the glass transition, but also for the understanding of dynamics in highly concentrated colloidal dispersions where crystallization is suppr…
Determination of the oxygen transmissibility and permeability of hydrogel contact lenses
1999
To test the validity of the method of stacked hydrogel contact lenses to obtain the oxygen permeability and transmissibility coefficients of the lenses, the coefficients of one low hydration (38% water) and two high hydration (55 and 58% water) hydrogel contact lenses stacked one to five on an oxygen electrode were deter- mined. From the oxygen diffusion through the lenses, the current intensity in the stationary state was determined, and from this the "instrument" the oxygen transmis- sibility was obtained. The permeability coefficients of the lenses, corrected for edge effects, were obtained from the slope of the plot of the reciprocal of the transmissibility coefficients versus the lens …
Sumatriptan Succinate Transdermal Delivery Systems for The Treatment of Migraine
2007
We have successfully obtained sumatriptan transdermal systems with different polymer compositions: methyl cellulose (MC), polyvinyl pyrrolidone (PVP) and a polyvinyl pyrrolidone (PVP)-polyvinyl alcohol (PVA) mixture. The systems contained 1,2-propylenglycol (MC) or sorbitol as a plasticizer (PVP and PVP-PVA), methacrylate copolymer as an adhesive agent, and an occlusive liner. Azone (5%, w/w) was incorporated into all the systems as a percutaneous enhancer. Transdermal systems are thin, transparent and non-adhesive when in a dry state. The permeation of sumatriptan succinate across pig ear skin was studied using the systems prepared. The formulation with MC polymer produced a statistically …
FINITE ELEMENT RESOLUTION OF CONVECTION-DIFFUSION EQUATIONS WITH INTERIOR AND BOUNDARY LAYERS
1996
We present a new algorithm for the resolution of both interior and boundary layers present in the convection-diffusion equation in laminar regimes, based on the formulation of a family of polynomial-exponential elements. We have carried out an adaptation of the standard variational methods (finite element method and spectral element method), obtaining an algorithm which supplies non-oscillatory and accurate solutions. The algorithm consists of generating a coupled grid of polynomial standard elements and polynomial-exponential elements. The latter are able to represent the high gradients of the solution, while the standard elements represent the solution in the areas of smooth variation.
Hygrothermal effect on moisture kinetics and mechanical properties of hemp/polypropylene composite: Experimental and numerical studies
2015
The exposition of thermoplastic composites reinforced with natural fibers to moisture and heat is likely to lower their mechanical properties and restrain their use in the design of parts. The present work is focussed on investigating the effects of hygrothermal aging on the mechanical behaviour of injected polypropylene reinforced with short hemp fibers. Moreover, the kinetic of isothermal moisture absorption has been studied for four immersion temperatures. The experimental results show that the time taken to reach saturation decreases significantly with increase in immersion temperature. These tests also reveal that moisture absorption in this type of materials does not follow Fick's law…
Thermal stability of PP with acetylated sisal fiber: Romero Garc�a kinetic method
2003
This work deals the effect of acetylated and non-acetylated sisal fiber 011 thermal degradation of polypropylene. Applying the R-G method at constant conversion levels of 0.1, 0.3, 0.5, 0.7 and 0.9 to thermograms of the ”PP/untreated sisal fiber” blend, E, values of 99, 213, 224, 187, and 145 kJ/mol were obtained, whereas they were 99, 299, 255, 205, 154 kJ/mol for the “PP/treated sisal fiber” blend. On the other hand, with the R-G method at constant temperature, activation energies within the range of 156-417 kJ/mol were obtained for the “PP/treated sisal fiber” blend and within the range of 126-344 kJ/mol for the “PP/untreated sisal fiber” blend. Additionally, the method establishes as do…
Calculation of small-angle neutron scattering by macromolecules in the semicrystalline state
1980
The conformation of macromolecules in the semicrystalline state has been studied by various authors with respect to the validity of the adjacent re-entry — or switchboard model by application of small-angle neutron scattering. Analytical as well as Monte-Carlo calculations show that the experimental results for melt crystallized polyethylene and isotactic polypropylene can be interpreted on the basis of the solidification model. In this model it is assumed that crystallization occurs by straightening of coil sequences without a long range diffusion process.
Physicochemical stability of cabazitaxel containing premix solution and diluted infusion solutions
2015
Objectives This study was conducted to investigate the extended physicochemical stability of cabazitaxel containing premix solution and diluted infusion solutions in either 0.9% sodium chloride (NaCl) or 5% glucose (G5) vehicle solution. Methods A stability indicating, reverse phase, high performance liquid chromatography assay with ultraviolet detection was developed and validated. Premix solutions of cabazitaxel were prepared in the original vials. Infusion solutions were prepared in prefilled polypropylene/polyethylene (PP/PE) infusion bags (0.9% NaCl, G5) to achieve the recommended minimum and maximum cabazitaxel concentrations (0.1 mg/mL, 0.26 mg/mL). Test solutions were stored refrige…