Search for dissertations about: "matrix diffusion"

Showing result 1 - 5 of 153 swedish dissertations containing the words matrix diffusion.

2. 1. Modelling of Drug Release from Reservoir and Matrix Formulations - Multiple Unit Dosage Forms and Swelling and Dissolving Matrix Systems

   Author : Per Borgquist; Avdelningen för kemiteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swelling; XEDS; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Polymer technology; biopolymers; Polymerteknik; Pharmaceutical and related technologies; Läkemedelsteknik och relaterad teknik; simulation; single pellet; single-unit release; SEM; reservoir system; poly ethylene oxide ; film-coated; matrix; mathematical model; diffusion; pellet shape; controlled release; polymer dissolution; modelling; ethyl cellulose; Coating; multiple-unit release;

   Abstract : In this work, mathematical models have been developed describing drug release from film-coated reservoir systems as well as drug release and polymer dissolution from swelling and dissolving polymer tablets. The model derivation of both systems is based on a mechanistic approach. The model describing drug release from reservoir systems, i.e. READ MORE

4. 2. Studies of ionic diffusion in crystalline rock

   Author : Yvonne Ohlsson; KTH; []
   Keywords : matrix diffusion; surface diffusion; surface conductivity; nuclear waste; rock; mineral; electrical conductivity;

   Abstract : .... READ MORE

5. 3. NMR diffusion studies on lyotropic liquid crystalline systems

   Author : Greger Orädd; Frank Volke; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Diffusion; pulsed field gradient; liquid crystalline systems; lipid lateral diffusion; cubic phases; peptide-lipid interactions; hydrophobic mismatch; permeability;

   Abstract : The pulsed field gradient fourier transform nuclear magnetic resonance (PFG-FTNMR) method to measure translational diffusion coefficients in multicomponent systems has been applied to amphiphilic molecules forming liquid crystalline phases.By analyzing the concentration dependence of the diffusion coefficients of water and amphiphile in a micellar system of N,N-dimethyldodecy lamine oxide (DDAO) in water it was possible to conclude that the micelles formed were polydisperse in size and shape. READ MORE

6. 4. Computational Diffusion MRI: Optimal Gradient Encoding Schemes

   Author : Mohammad Alipoor; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gradient Encoding Scheme; ADC imaging; Diffusion MRI; D-optimal experiment design; Diffusion Tensor Imaging; Optimal Image acquisition; Second and Fourth Order Tensors.; Diffusion Kurtosis Imaging;

   Abstract : Diffusion-weighted magnetic resonance imaging (dMRI) is a non-invasivestructural imaging technique that provides information about tissue microstructures.Quantitative measures derived from dMRI reflect pathologicaland developmental changes in living tissues such as human brain. READ MORE

7. 5. Drug Diffusion and Nano Excipient Formation Studied by Electrodynamic Methods

   Author : Ulrika Brohede; Maria Strømme; Göran Frenning; Hans Leuenberger; Uppsala universitet; []
   Keywords : Functional materials; drug release; electrodynamic methods; diffusion; Funktionella material;

   Abstract : New smart drugs demand new smart drug delivery systems and also new smart analysis methods for the drug delivery process and material characterization. This thesis contributes to the field by introducing a new electrodynamic approach for studying the drug diffusion proc-esses as well as the formation of a new type of drug delivery systems, the so called mesoporous nano excipients. READ MORE