Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 23 for “"Permeation Experiments"”.
-
HYPERION: A HYdrogen PERmeatION Experiment to Quantify Hydrogen Transport in Fusion-Relevant Molten Salts
… of measuring these properties is with hydrogen permeation experiments. Hydrogen permeation experiments involve measuring the flux of hydrogen permeating through a substance, and from this flux transport properties like the diffusivity and solubility of hydrogen in the molten salt can be derived …
-
Hydrogen transport in and through niobium
"Two separate experiments were performed in order to understand the roles of bulk diffusion and surface processes in hydrogen transport in and through niobium. Bulk hydrogen and deuterium diffusivities and permeabilities were measured at high temperatures (700 -1400 K) using diffusion controlled …
-
Löslichkeitsselektive Mixed Matrix Membranen zur Gaspermeation
… and methane. For mathematical description of the permeation process a new model is developed based on one-dimensional discretisation of the separation layer. This is an innovative approach for modelling of mixed matrix membranes and can also be applied for other systems than the one investigated …
-
Investigation of membrane permeation using ATR-FTIR spectroscopic imaging and multivariate target factor analysis
… in vitro monitoring of the mechanisms of drug permeation and the effects of penetration enhancers on silicone membrane and human stratum corneum (SC). Simulated spectroscopic imaging data sets were used to validate the scope and application of quantitative iterative target transformation factor …
-
Caratterizzazione di membrane inorganiche per la separazione di idrogeno da gas di reforming
… ones with pinholes in the metal layer. Mixtures permeation experiments reveal also concentration polarisation phenomena and hydrogen permeability reduction due to carbon monoxide adsorption on metal surface.
-
Surface-enhanced Raman and surface plasmon resonance measurements of Case II diffusion events on the nanometer length scale
… spectra of the polymer/penetrant system during permeation experiments. Penetrant motion and polymer relaxation processes may be simultaneously monitored in situ by interpretation of vibrational mode evolution. Polymer relaxation and deformation in response to osmotic stress caused by the …
-
Layer by Layer, Nano-particle "Only" Surface Modification of Filtration Membranes
… typical NF operating conditions using dead-end permeation experiments and their performance compared quantitatively with realistic hydrodynamic models, with favorable results. For track etched polycarbonate MF substrates, surface modification causes a permeability reduction of approximately two …
-
Gas transport properties in polycarbonate - Influence of the cooling rate, physical aging, and orientation
… and shape distribution. Results obtained from permeation experiments were accompanied with dynamic mechanical and density measurements. The experimental results suggest that the diffusion coefficient of small gas molecules in glassy polycarbonate is influenced by the local dynamics or mobility …
-
Novel covalent organic framework (COF) thin-film composite nanofiltration membrane for effective removal of organic compounds from petroleum produced water
… compounds present in treated produced water. Permeation experiments with the COF membrane resulted in 60-70% rejection for three model compounds, Propyl-, Butyl- and Pentyl-benzoic acids, along with 85-90% rejection of the higher-molecular weight organic surrogate, Rhodamine-WT (R-WT), and …
-
Hydrogen permeation in uncoated and coated X60steel
… PhD research investigates hydrogen diffusion and permeation in API 5L X60 pipeline steel, with a focus on the development and validation of experimental and analytical methodologies to evaluate RF-magnetron-sputtered tungsten coatings as hydrogen permeation barriers. A combined electrochemical and …
-
Effect of a novel contraceptive compound on vaginal health
… and enter circulation, we preformed tissue permeation experiments using Mattek's 3D human EpiVaginal tissue. B1 was not able to traverse human vaginal ectocervical cells in vitro. Next, we tested B1's permeability in a murine in vivo model, again finding that B1 was not able to permeate the …
-
Remoção de CO2 do biogás por permeação em membranas
… for CO2 removal from biogas: membrane gas permeation and membrane contactors. Both technologies were compared regarding purification efficiency, energy requirements and membrane area. Gas permeation experiments were performed using two commercially available membranes, in which different …
-
Hydrogen Transport and Hydrogen Embrittlement in Stainless Steels (Diffusion, Permeation, Solubility, Slow Crack Growth)
… metastable austenitic stainless steels, hydrogen permeation and/or cracking velocity were measured and compared for three types of stainless steels. These included austenitic, ferritic, and duplex ((gamma)/(alpha)) alloys. Deformation in AISI 301 resulted in various amounts of (alpha)' martensite, …
-
The preparation and characterization of hollow fibre membranes for gas separation
… gases and gas mixtures was studied. Both the permeation rate constants and the separation factors determined from the mixture permeation were found to be lower than the values predicted from the single gas permeation experiments. A model was developed to help understand the competitive nature …
-
Modified Nafion membranes for hydrogen production in Cu-Cl thermochemical cycle
… with pyrrole and aniline compounds. Ex situ permeation experiments were performed along with impedance spectroscopy to investigate the rate of the copper crossover and the proton conductivity of the composite membranes, respectively. The electrochemical behavior of the composite membranes was …
-
Polyimide-Organosilicate Hybrid Materials: Part I: Effects of Annealing on Gas Transport Properties; Part II: Effects of CO2 Plasticization
… and CO₂-CH₄ permselectivity. The increase in permeation was attributed to increases in the free volume and enhanced segmental mobility of the chain ends resulting from the removal of sol-gel condensation and polymer degradation byproducts. For the second study, the transport properties of four …
-
Caratterizzazione di membrane metalliche e ionomeriche per applicazioni energetiche
… 200 and 400 °C up to 12 bar of pressure) and permeation experiments of pure hydrogen and mixtures containing, besides hydrogen, also nitrogen and methane at high temperatures (up to 600 °C) and pressures (up to 10 bar). Sequential deposition of palladium and silver on to porous alumina tubes …
-
Mixed Gas Transport Study Through Polymeric Membranes: A Novel Technique
… separation technologies. Membrane separation and permeation characteristics for a particular mixed gas system is typically calculated from single-component transport parameters, namely, diffusion coefficients and solubility constants. In certain gas systems involving gaseous or vapor mixtures, …
-
Experimental and finite element analysis of mechano-electrochemical effects in intervertebral disc biomechanics
… FE models and experimental data. Direct permeation experiments found that fluid velocity may be augmented through the nucleus pulposus via ionic osmotic pressure gradients which consist of fixed charge, mobile ion and electrical potential gradients. A novel method to fully characterise, …
-
Preparation and Characterization of Lyophilized Cyclodextrin Complexes of a Hemisuccinate Ester of Delta-9-Tetrahydrocannabinol for Transmucosal Delivery
… on chemical and enzymatic stability and in vitro permeation across excised buccal mucosa of THC-HS. There was a significant reduction in chemical hydrolysis of complexed prodrug as compared to free prodrug. RAMEB afforded better stability profile and lower degradation rate constants as compared to …
Page 1 of 2