In gas-condensate reservoirs, production rate starts to decrease when retrograde condensation occurs. As the bottomhole pressure drops below the dewpoint, gascondensate and water buildup impede flow of gas to the surface. To stop the impairment of the well, many publications suggest wettability alteration to gas-wetting as a permanent solution to the problem. Previous simulation work suggests an "optimum wetting state" to exist where maximum gas condensate well productivity is reached. This work has direct application in gas-condensate reservoirs, especially in identifying the most effective stimulation treatment which can be designed to provide the optimum wetting conditions in the near-wellbore region. This thesis presents an extensive experimental study on Berea sandstone rocks treated with a fluorinated polymer. Various concentrations of the polymer are investigated to obtain the optimum alteration in wettability to intermediate gas-wet. This wetting condition is achieved with an 8% polymer solution treatment, which yields maximum gas mobility, ultimately increasing the relative permeability curves and allowing enhanced recovery from gas-condensate wells. The treatments are performed mainly at room conditions, and also under high pressure and high temperature, simulating the natural environment of a reservoir. Several experimental techniques are implemented to examine the effect of treatments on wettability. These include flow displacement tests and oil imbibitions. The experimental work took place in the Wettability Research Lab in Texas A&M University at Qatar in Doha, Qatar. The studies in this area are important to improve the productivity of gas-condensate reservoirs where liquid accumulates, decreasing production of the well. Efficiency in the extraction of natural gas is important for the economic and environmental considerations of the oil and gas industry. Wettability alteration is one of the newest stimulation methods proposed by researchers, and shows great potential for future research and field applications.

Background: Chemotherapy has side effects that may interfere with food intake. Children suffering from a malignant disease are subjected to treatment with chemotherapy. They may therefore become at risk of undernutrition during the period of treatment. This in turn may increase the risk of infections, delayed therapy and influence the outcome of treatment. Few studies have investigated how children undergoing chemotherapy for cancer perceive food and eating. Attempts to improve food intake and the nutritional status require an understand-ing of how eating patterns are altered during chemotherapy in children. Study design: Dietary information and anthropometric data were collected after the initiation of chemotherapy in 14 children, consecutively admitted to the Paediatric Haematology and Oncology Unit at Umeå University Hospital. This initial study resulted in the establishment of more flexible mealtime routines on the ward. A follow-up study was conducted with another group of 11 children. Interviews were performed with a third group of 21 consecutively ad-mitted children, their parents and attending nurses. The focus was on the children’s own per-ception of and their parents’ and nurses’ attitudes to their food intake during hospitalisation. Recognition thresholds for the basic tastes were determined with 10 of the oldest of these children and 10 healthy controls. Results: Before introduction of new mealtime routines, the average daily oral energy intake during hospitalisation was 58% of the Swedish Nutrition Recommendations, SNR. The chil-dren had a significant weight loss up to three months after onset of chemotherapy. After the introduction of new mealtime routines, the average daily oral intake on hospital days was 61% of SNR and thus still lower than recommended despite efforts to serve palatable food on the ward. When enteral and parenteral nutrition was included, the energy intake came close to that recommended for healthy children, 91% of SNR. Both children and parents perceived that altered taste was an important cause of the children’s eating problems. The children also viewed food aversions, nausea and vomiting and pain as important causes, while the parents perceived nausea, food aversions and altered smell as significant factors. The nurses on the other hand, viewed nausea, the ward environment, and food rejection as a way of gaining some influence over the situation as important factors. The patients had significantly higher thresholds for bitter taste and significantly more patients made mistakes in taste recognition compared with controls. Conclusion and clinical implication: There seem to be changes both in the sense of taste as well as in the perception of food in children undergoing chemotherapy for malignant disease. Thus, single solutions such as providing a variety of “tasty food” in the hospital setting in order to improve food intake does not suffice for many paediatric cancer patients. The indi-vidual’s food preferences and aversions should be considered and combinations of oral, en-teral and parenteral nutrition support should be provided.

¡@¡@Igneous activity of Taiwan in Miocene mainly were concentrated in the area north of Miaoli. Nanman is one of the basalt in southern of Taiwan that had been studied by OM, XRD, SEM/EDS and TEM. The rock type is alkali basalt with phenocryst of augite and olivine. The primary minerals include olivine + augite + plagioclase + Anorthoclase + apatite +titanomagnetite + illmenite, and secondary minerals are chlorite + smectite + calcite ¡Ó gypsum.Alteration of Nanman basalt was take placed in mixture and crack of olivine, other minerals are almost fresh. The main replacement are chloritic minerals shown five occurrence types : (1) replaced mixture, (2) vein center of olivine crack, (3) vien of olivine, (4) fibrous and (5) mica-like clay between vein and residual olivine. Each types has clear grain boundary. It¡¦s mean they are not gradual. (4) and (5) are smectite with anomaly composititon. It cause by lack of Al resource, and smectite occurred far from the crack that element do not easily move. Thus, smectite replaced olivine often showed Al-poor and excess Mg. Si/(Si+Al) and Fe/(Fe+Mg) in smectite is positive correlation. This may be considered the moving ability of elements. Composition of (1), (2) and (3) are chlorite/smectite. However there is no observed mixed-layer minerals in XRD. According to TEM , they are chlorite + smectite. Chlorite within abundant of dehydrated cracks could be a evidence of smectite. Because of mixed chlorite and smectite, the correlation between Si/(Si+Al) and Fe/(Fe+Mg) is negative. Different occurrences lead to different mineral, suggest water/rock ratio is an important control factor. High rock/water ratio trend to form chlorite, and low rock/water ratio prefer to form smectite. According to all the results, the steps of altered olivine are first forming chlorite at mixture and olivine cracks. Then, the residual olivine becomes smectite with poor Al and excess Mg, when the rock was cooling down.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 211-235). Also available for download via the World Wide Web; free to University of Oregon users.

This work helps increasing our general understanding of how plants behave under altered hydrological conditions which occur along rivers regulated by hydropower dams. Usually, natural-real environments are highly unpredictable. Consequently, research based on field data becomes challenging and results may contain uncertainty. Here, an experimental design in a greenhouse is developed. Several measured attributes of selected plant species related to germinability, performance and survival were used as indicators of the impact of watering treatments which mimic hydrological regime spilled through hydropower dams. Specifically, direct effect<img src="https://cdncache-a.akamaihd.net/items/it/img/arrow-10x10.png" /><img src="https://cdncache-a.akamaihd.net/items/it/img/arrow-10x10.png" /> of water availability changes, water fluctuation and water flooding, and indirect effect<img src="https://cdncache-a.akamaihd.net/items/it/img/arrow-10x10.png" /> through derived erosion, were tested. Results benefitted from indoors controlled conditions. They showed significant different responses depending on species and hydrological changes. In general, Helianthus annuus was slightly affected. It deal well flooding conditions, and was comparatively more affected by water fluctuation and stress. Carex and Filipendula species showed the highest sensitivities to flow. They hardly germinated under any water treatment (few germinations under flooding for Carex and few under water fluctuation for Filipendula) and performance was very low for germinates. Betula pubescens was in between. Contrarily to Helianthus, it was severely affected by flooding, and also for water fluctuation. It survived water stress better than Helianthus, but looked unhealthy. All species seeds but Helianthus were highly eroded. However, erosion resulting<img src="https://cdncache-a.akamaihd.net/items/it/img/arrow-10x10.png" /> from water fluctuation was relatively higher than from prolonged flooding. Differing responses are the result of morphological and physiological characteristics of the species which enable them to success under certain stressful conditions, such as water scarcity and anoxia. These results objectively inform about tolerance limits of selected species to key hydrological conditions and are useful for riparian areas management and environmental flows designs.

No description available.

Thesis (Ph. D.)--Carleton University, 1999. / Also available in electronic format on the Internet.

Thesis (M.S. in Geology)--Vanderbilt University, Aug. 2006. / Title from title screen. Includes bibliographical references.

Multiple generations of normal faults dismembered, tilted, and exposed thicknesses of up to 15 km of the upper crust in portions of central and southern Arizona. This extension, variable in distribution and magnitude, was superimposed on the axis of the Laramide magmatic arc and dismembers many porphyry copper systems, allowing for detailed study of vertical and lateral zonation of alteration around these centers. This study examines tilted fault blocks containing portions of porphyry systems across Arizona, focusing on hydrothermal alteration deep and distal in these systems (3+ km paleodepth) to develop a more complete understanding of porphyry occurrences as larger geochemical systems. This study focuses on Na-Ca and coarse muscovite alteration in the roots of Laramide porphyry copper systems across Arizona (Ajo, Sierrita, Kelvin-Riverside, Mt. Grayback, Granite Mountain, Charleston, Globe-Miami, Sycamore Canyon, Copper Basin, Texas Canyon, and Copper Creek), provides a detailed study of Middle Jurassic coarse muscovite alteration at Luhr Hill in the Yerington district, Nevada, and documents the structural and hydrothermal evolution of the Ajo mining district in southwestern Arizona. Most areas in this study are interpreted to be highly extended, highly eroded, or both, allowing for study of deep hydrothermal alteration. Na-Ca alteration has been previously documented extensively along the Jurassic arc of the southwestern United States but less widely known in younger plutons, notably of Laramide age in Arizona. Coarse muscovite alteration previously has rarely been documented in porphyry copper systems, and this study shows that coarse muscovite alteration is likely present in systems where root zones are exposed at surface. Na-Ca alteration also is present in many in Laramide porphyry systems, though volumetrically minor, as no Laramide system contains more than a few volume perfect Na-Ca alteration in a given hydrothermal system. Na-Ca alteration in Laramide systems can include Ca, Na-Ca and Na alteration but is dominated by Na alteration (epidote-albite-chlorite ± actinolite). At Ajo, both Na-Ca and coarse muscovite alteration are present within the district due to superposition of temporally unrelated hydrothermal alteration, coupled with complex extensional deformation. This study shows that both Na-Ca and coarse muscovite alteration are more common in Laramide porphyry copper systems than previously recognized, that Na-Ca alteration is most commonly developed as shallower Na alteration (albite-epidote-chlorite ± actinolite), common deeper Na-Ca alteration (oligoclase-actinolite-epidote), and rare, deep Ca alteration (oligoclase-diopside-actinolite ± garnet ± epidote). Na-Ca alteration is commonly less voluminous in Laramide systems than documented in systems along the Jurassic arc. Coarse muscovite alteration, commonly termed greisen, occurs structurally below and commonly postdates potassic alteration and likely formed from late-stage, low-temperature, magmatic-hydrothermal fluids. Coarse muscovite alteration associated with more silicic magmatic compositions is developed at shallower depths and contains muscovite with higher trace element contents, coarse muscovite alteration with more variable mineral assemblages, and coarse muscovite veins that are better mineralized. Coarse muscovite alteration (greisen) occurs as the main mineralized veins at the tops of evolved metaluminous to peraluminous granites in W-Sn systems, as well mineralized veins in the cores and tops of Mo-Cu porphyry systems, and as poorly mineralized veins in the roots of porphyry copper systems. Detailed understanding of coarse muscovite alteration in a given district can, therefore, can be an indicator of depth or petrologic affiliation of a system. These results provide a better understanding of late-stage magmatic-hydrothermal alteration and hydrothermal alteration associated with the incursion of external fluids into the root zones of porphyry copper systems.

Mineral hydration is known to result in low flotation recoveries and grades within primary platinum group element ores worldwide. This is because the phyllosilicate minerals derived from hydration reactions of silicate minerals (i) form electrostatic coatings on valuable minerals that in turn hinders collector adsorption, (ii) alter the viscosity of the slurry leading to poor gas dispersion and (iii) decrease the concentrate grade due to naturally-floating gangue. Sodium metasilicate was investigated because its dispersant, rheology modifying, and depressant properties could prove promising in combating the problems associated with these ore types. Quantitative evaluation by scanning electron microscopy (QEMSCAN) analysis revealed large quantities of serpentine and talc present within the ore sample used in this study, which led to a poor flotation response, as indicated by batch flotation tests. Using sodium metasilicate improved the recoveries and grades at high dosages (>1000 g/t). A suite of techniques was chosen to decouple sodium metasilicates' effects to answer why an improved flotation performance occurred. The zeta potential experiments indicate that improved recoveries are, in part, as a result of the reversal of serpentines surface charge, creating electrostatic repulsion between serpentine and valuable minerals which prevents the coating of valuable minerals by serpentine slimes. This corresponded with improved recoveries of a PGM proxy in the presence of serpentine slimes and a high sodium metasilicate dosage. Ore dilution and rheology tests indicate that decreased viscosity at high dosages also improved recoveries. This was supported by slower particle settling rates at high sodium metasilicate dosages during particle settling measurements. Talc micro-flotation tests revealed that the depression of talc occurred at higher sodium metasilicate dosages, which improved concentrate grade. This was supported by a QEMSCAN concentrate analysis of the sodium metasilicate batch flotation concentrates, which confirmed that talc, and other associated silicate minerals, were depressed at high sodium metasilicate dosages. The processing of near-surface altered ores is becoming an increasing problem worldwide and the use of sodium metasilicate proved valuable in mitigating the problems associated with the altered ore investigated in this study.