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The application of a mineral admixture, or a corrosion inhibitor, or a combination of both are methods used for the corrosion protection for reinforced concrete bridges. The results of a study on evaluation of corrosion inhibitors from three different manufacturers and of concretes with fly ash, slag cement, and silica fume and a concrete with silica fume and a corrosion inhibitor are presented. The specimens were built to simulate four exposure conditions typical for concrete bridges located in the coastal region or inland where deicing salts are used. The exposure conditions were horizontal, vertical, tidal, and immersed zones. The specimens were kept inside the laboratory and were exposed to weekly ponding cycles of 6% (w/w) sodium chloride solution. In addition, cover depth measurements from 21 bridge decks and chloride data from 3 bridge decks were used, together with laboratory data, in modeling the service lives of the investigated corrosion protection methods. The methods used to assess the condition of the specimens included chloride concentration measurements, corrosion potentials, and corrosion rates (3LP). Additionally, visual observations were performed for identification of rust stains and cracking on concrete surfaces. Modeling the time as a function of probability of the end of functional service life (EFSL) is presented. It has been shown that the distributions of surface chloride concentration, C0, and diffusion coefficient, Dc, are key elements in the model. Model predictions show that the concretes with mineral admixtures provide much better level of protection against moisture and chlorides than the ordinary portland cement concrete alone. Application of a corrosion inhibitor causes an elevation of the chloride threshold resulting in an additional increase in time to EFSL. More field studies are needed to better estimate distributions of surface chloride concentration and diffusion coefficient of Virginia bridge decks, and to confirm predicted times to EFSL for low permeable (LP) concretes. / Ph. D.

In the last decade, there has been renewed interest in the use of granulocyte transfusions to treat infections in individuals with compromised immune systems. However, granulocytes only remain functional for about a day after isolation and this short shelf life is a significant drawback. Cryopreservation would allow long term storage of granulocytes, but an effective cryopreservation method is currently unavailable. The following study was performed to provide membrane permeability values for multiple cryoprotectants in hopes of aiding the optimization of cryoprotectant addition and removal and minimizing the detrimental effects of the process. The granulocytes were separated from whole blood using centrifugation with Polymorphprep as the separating agent. The cellular membrane permeability values were then measured using a Beckman Coulter Counter Multisizer 3 under custom setup conditions. The cryoprotectants studied were glycerol, DMSO, ethylene glycol, and propylene glycol at the respective total concentrations of 1, 2, 2, 1 Osm/kg at temperatures of 4, 21, and 37 °C. The resulting membrane solute permeability values at 20 °C reference temperature for DMSO, ethylene glycol, glycerol, and propylene glycol were respectively 5.96, 7.84, 0.950, and 3.45 um/min and the Arrhenius activation energies were respectively 60.4, 58.7, 68.2, and 62.3 kJ/mol. The resulting hydraulic permeability values in the same order and temperature were 0.196, 0.189, 0.259, and 0.113 um/(atm min) and the Arrhenius activation energies were respectively 56.3, 60.7, 68.5, and 47.1 kJ/mol. It is anticipated that these permeability values will aid in the development of successful cryopreservation procedures for granulocytes. / Graduation date: 2013

Abstract The studies measure the porosity, permeability of porous structures with different grain size and shapes such as those of crushed gravels and glass balls. Then discuss the relationship between various coefficients like intrinsic permeability, dimensionless turbulent coefficient, Reynolds number and so on in previous experimental formula¡]Ward¡A1964¡^and writer's formula from practical physics conceptions . Physics conceptions particularly consider respectively sheer flow effect and vortex effect in porous flow field. The study will be considered as the first phase in a full study of the resistance force inside porous structure.

The effect of antiplasticization on barrier properties of poly(ethylene terephthalate) (PET) has been investigated through transport measurements and some supplementary characterization techniques including dynamic mechanical measurements and solid state 13C cross polarization/magic angle spinning (CP/MAS) NMR. Our oxygen and carbon dioxide transport results were well described by a combination of the free volume based interpretation and interaction energy estimation. Transport characterization and DSC techniques verified that there exists a third element, a de-densified amorphous fraction in crystallized PET. Both oxygen and carbon dioxide permeabilities at 1 atm at 35ºC in PET with different crystallinities were well described by the Nielsen model due to the presence of an adjustable parameter, Ar, even though it is based on a two phase model. The comparison of the barrier improvement factor (BIF) values for samples annealed at 100ºC demonstrated that a combination of antiplasticization and crystallization allows for very efficient chain packing, which significantly improves the barrier properties of PET. A thorough molecular level study using dynamic mechanical analysis supported the synergistic effect of antiplasticization and crystallization on the molecular motion in PET. Lastly, a vapor/gas permeation system with a new concept of a flexible humidity and methanol vapor partial pressure clamp was designed and constructed. Even though its permeation results are not available at this point, its operational feasibility was well verified by pre-calculations and physical explanations. This system may be used for future studies to evaluate barrier properties of PET or modified PET samples.

To clarify the role of charge in protein movement across the pulmonary endothelial barrier, we simultaneously measured the permeability-surface area product (PS) for native [isoelectric point (pI) 4.4-5.1] and cationic (pI 7.2-8.0) albumin in isolated rabbit lungs perfused with and without protamine sulfate. We focused our measurement on the initial (endothelial) barrier by using a technique that is based on the very rapid (3 min) uptake of tracer. This allowed us to distinguish the charge properties of the endothelium separate from other barriers. In control studies, PS was greater for cationic than for native albumin (8.67 ± 0.93 vs. 2.55 ± 0.20 x 10-2 ml · min-1 · g dry lung-1). In the presence of 1 mg/ml protamine sulfate, cationic albumin permeability was not different from control (7.34 ± 0.49 x 10-2 ml · min-1 · g dry lung-1), whereas PS for anionic albumin increased to 8.82 ± 1.32 x 10-2 ml · min-1 · g dry lung-1. Thus the protamine sulfate eliminated the difference between native and cationic albumin PS. This selective increase in anionic albumin permeability is presumably due to the cation, protamine sulfate, binding to the anionic charges on the endothelium and reducing the anionic charge-charge repulsion. If protamine sulfate had produced a general endothelial injury, the PS for both albumins would have increased. Our results suggest that the normal pulmonary endothelium is an anionic charge barrier restricting the transcapillary movement of negatively charged molecules.

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