Every year, millions of people in the world die from cardiovascular diseases. Most of thesevictims show no symptoms of disease for decades as the disease silently progresses, but maysuddenly become afflicted with a myocardial infarction or stroke. At present there is aregrettable lack of important disease markers that could help identify patients at risk withregard to secondary cardiovascular events. Biomarkers for this would of course be extremelyvaluable. If such markers could distinguish between patients with different responses totreatment and overall outcome, that would be of major added value as this potentially couldpave the way for differentiated preventive measures. In this study we show that specificproteins isolated from plasma-derived exosomes are indeed associated with an increased riskfor secondary cardiac events.

Produced water and spent drilling fluids from petroleum operations represent a significant expense to companies developing new energy reserves. These spent fluids, seldom recycled, offer a viable source of water resources for oil-field reuse. A major obstacle to reuse is the presence of suspended solid material in the fluids. Such contaminants, if not removed, will not only prevent any reuse but will also impede disposal. The objective of this project was to evaluate membrane filtration as a way to remove suspended and entrained particles to produce re-useable effluents using membranes. Ceramic and Polyvinylidene Flouride (PVDF) hollow fibre membranes were used in laboratory scale experiments in the investigation of the colloidal filtration of field produced spent drilling fluids and produced water. Feed parameter and operational parameter evaluation of ceramic and PVDF hollow fibre membrane filtration of spent drilling fluids and produced water showed that feed concentration, solids in the spent drilling fluid and oil in the produced water, is the most important parameter during membrane filtration. Operational parameter variation showed that high cross flow velocity was beneficial in flux maintenance during spent drilling fluid filtration due to its high solids concentration because of the scouring effect on the cake layer on the membrane surface. Pressure regimens were important in flux decline as relatively high pressures accelerate the consolidation of the concentration polarization layer causing flux decline. High temperatures were generally beneficial for increased flux in the filtration of produced water and spent drilling fluids. Resistance calculations were used to deduce the contribution of individual resistances during the ceramic filtration of produced water and spent drilling fluids and were identified as a real-time tool for monitoring membrane integrity and fouling. Backwashing as a fouling mitigation technique was effective in flux maintenance in ceramic membranes especially in the filtration of produced water; cleaning solutions were effective in flux recovery in ceramic membrane filtration and to a slightly lesser degree in hollow fibre membrane filtration. A methodology in determining the suitability of water based oil field wastes using membranes was developed to help future investigations of this type.

Abstract Studies of phase speciation of trace metals were conducted in Kaohsiung harbor and coastal areas in April and May 2002. Water samples were collected from three different sampling stations to study the spatial distribution of metal species. Colloidal and truly dissolved subsamples were observed by cross-flow filtration treatment. The results show that TOC of seawater samples ranged from 4.17 mg/L to 7.17 mg/L. For trace metals, zinc had the highest concentration(7.21 £gg/L ¡ã14.14 £gg/L), followed by manganese(3.31 £gg/L ¡ã 11.73 £gg/L), copper(0.28 £gg/L ¡ã 7.57 £gg/L), lead(2.41 £gg/L ¡ã 4.41 £gg/L), nickel(1.78 £gg/L ¡ã 2.97 £gg/L). Highest concentrations of TOC and metals were observed in Kaohsiung harbor(S1), and the values decreased in the order of S1 ¡Ö S2 ¡Ö S3. Distribution of phase speciation of trace metals varied with location. Nickel existed in truly dissolved phase predominately(66 ¢Mat S1, 79.7 ¢Mat S2 and 84.6 ¢Mat S3). For the other metals, either particle or truly dissolved phase was the major species at each sampling station. For zinc, 56.1 ¢Mat S1 was in truly dissolved phase, 68.1 ¢Mat S2 and 59.6 ¢M at S3 were in particulate phase. For copper, 67.5 ¢Mat S1 was in particulate phase, 56.7 ¢Mat S2 and 89.9 ¢Mat S3 were in truly dissolved phase. For manganese, 56.3 ¢Mat S1 was in truly dissolved phase, 79.8 ¢Mat S2 and 72.1 ¢Mat S3 were in particulate phase. For lead, 51.7 ¢Mat S1 and 66.0 ¢Mat S3 were in truly dissolved phase, 63.5 ¢Mat S2 was in particulate phase. The percentages of TOC and metals in colloidal phase of the filter-passing pool were low at all sampling stations and decreased in the order of S1 ¡Ö S2 ¡Ö S3. They were found predominately in truly dissolved fraction. The results also show that Kaohsiung harbor (S1) had the highest percentage of colloidal fraction, followed by coastal water (S2), open sea (S3). Values of partition coefficient between colloids and true solution(Kc ) in the Kaohsiung harbor and nearby coastal areas were lower than the Kc values observed in Galveston Bay during July 1995.

No description available.

Zugl.: Giessen, Universiẗat, Diss., 2009.

Reproduction de : Thèse de doctorat : Dynamique des fluides : Toulouse, INPT : 2005. / Titre provenant de l'écran-titre. Bibliogr. 87 réf.

Thèse de doctorat : Génie des procédés et des produits : INPL : 2008. / Titre provenant de l'écran-titre.

Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2008. / Titre provenant de l'écran titre. Bibliogr. p. 95-98.

Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2008. / Titre provenant de l'écran titre. Bibliogr. p. 80-88.

Thesis--University of Oklahoma. / Includes bibliographical references (leaves 45-46).