Spoil pile stability in an open pit coal mine is a common problem and the Red Hills Lignite Mine in Choctaw County is no exception. The mine has had spoil stability problems of their spoil dragline bench since the beginning of their activity in 2002. They have managed to stabilize the conditions by installing prefabricated vertical drains (PVD) to consolidate the layers below the spoil dragline bench, which tended to fail due to an increase in pore water pressure. In this study, the capability of analyzing and predicting future pore water pressure conditions is examined. With the use of the stability model Slope/w and local stress calculations, the predictability of the necessity of PVDs and their spatial distribution are analyzed. The outcomes prove to be circumstantial to local pore water pressure and geology changes, therefore, the spacing between drains could be adapted to the local conditions potentially saving costs.

N/A

This study measured the effects of spoil type and amendments on Appalachian mine soil properties over time. The Controlled Overburden Placement Experiment was installed in 1982 in two parts, the Rock Mix (RM) Experiment compares mixes of sandstone (SS) and siltstone (SiS) spoils while the Surface Amendment (SA) Experiment compares a fertilized control (CON), sawdust (SD at 112 Mg ha⁻¹), topsoil (TSâ 15 cm), and biosolids (BS) at 22, 56, 112 & 224 Mg ha⁻¹. Both experiments were sampled in 2008 and compared with historical data. After 26 years, all RM treatments had higher silt+clay and decreased sand. Mine soil pH and electrical conductance (EC) were lower in high SS spoils and overall pH was lower and EC higher in surface layers. Fe-oxides increased over time and adversely affected extractable P. Exchangeable cations and total N increased in all treatments. Annual C-sequestration rates were 0.51 Mg ha⁻¹ for 1:1 SS:SiS and 0.32 Mg ha⁻¹ for SiS. In the SA experiment, extractable P and exchangeable cations increased over time in organically amended plots. The CON and TS sequestered C at 0.54 Mg ha⁻¹ and 0.87 Mg ha⁻¹ annually while higher BS and SD treatments lost C, but mobilized significant C into their subsoils. In the SA, an apparent C retention maximum of 30-35 Mg ha⁻¹ was noted. Overall, rock type and amendment effects were still evident after 26 years and the long-term benefits of organic amendments were reflected in sustained higher C, exchangeable cations, total N and P levels. / Master of Science

Published as the author's thesis (doctor, Wageningen University, 2009). / Vita. Includes bibliographical references (p. 125-138). Includes list of author's publications (p. 147-149).

Published as the author's thesis (doctor, Wageningen University, 2009). / Includes bibliographical references (p. 125-138). Includes list of author's publications (p. 147-149).

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : [69]-72).

A vessel-mounted ADCP study focusing on channel-scale flow patterns in Galveston Bay near the Houston Shipping Channel and Mid-Bay Island is described. Winds of 5-7 m/s at 215-230◦ from N were present during data collection. For both peak ebb and flood conditions, the tidal circulation forced flow in a direction opposing the wind, perhaps due to a large-scale flow divergence forced by Mid-Bay Island. The strongest such currents were measured closest the island. During peak flood flow, the shape of the along-channel velocity profile for the open water upwind of the channel at Mid-Bay Island indicated uniform flow, and the salinity profile indicated a well-mixed water column. The near-island along- channel velocity profile showed a near-linear trend, and the salinity profile indicated a stratified water column. This suggested that the stratification had some effect the velocity profile shape, but further research is needed to better quantify this effect. During peak ebb flow, the near-island along-channel velocities were highly variable with respect to the mean velocity, indicating an area of active turbulence. Salinity profiles collected in the open water and near-island both showed stratification, something that was not seen during flood conditions. Differences in observations between flood and ebb flows can possibly be attributed to the survey location with respect to the chain of dredge spoil islands. During flood flows Mid-Bay Island is the first of the islands, and the flows surrounding the island may part of a developing horizontal boundary layer. During ebb flows the island is last in the chain relative to the direction of flow, and therefore the surrounding flows are well back from the leading edge of a horizontal boundary layer. / text

Minuartia verna (L.) Hiern and Thiaspi alpestre L. are recognized as relict elements of a preglacial montane flora in the British Isles and, as such, display a markedly disjunct distribution pattern. Their present-day distribution shows a close association with metalliferous mine workings, particularly in the Pennines, where both species have become prominent components of the flora of calcareous lead mine wastes. By comparison with M. verna, T. alpestre is more restricted in its distribution and is a rarer species. The work reported in this thesis attempted to provide an explanation for this pattern of distribution in the southern Pennines on the basis of comparative studies of the autecology and genecology of the species, their population biology and dynamics in the field and their responses to competition from other species. Both field and laboratory studies confirmed that the two species were highly tolerant of the heavy metals lead, zinc and cadmium. Short- and long-term solution culture experiments on tolerance and uptake of these heavy metals by a range of populations of both species are reported. Tolerance to other toxic metals was also investigated. T. alpestre showed superior tolerance to M. verna in these experiments, and emerged as a metal-accumulating species. M. verna by contrast, operated some degree of metal exclusion, but metal uptake and distribution differed for the various metals in both species and seasonally. Differences in metal tolerance and uptake characteristics alone could not explain the different local distribution patterns in the field, as sites of similar metal status are colonized by both the two species together and by M. verna alone. A study of inter-population variation in morphological characters showed considerable genetically-based variation in both species. M. verna was however more variable. Some of the variation detected was interpreted as being ecotypic in origin. The contrasting breeding of the two species and their seed biology are considered to be major factors in explaining the present-day distributions of the two species. The tendency for inbreeding in T. alpestre has severely limited its genetic variability within populations and potential for spread. Seedling mortality of both species in their natural habitats is very high, and survival can be related to early shelter effects of neighbouring plants. Both species, however, emerge as weak competitors as predicted from their preference for open habitats with much more bare ground. The relevance of these studies to the interpretation of the present-day global distribution of the two species and their evolutionary biology is discussed.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1982. / Includes bibliographical references (leaves 120-124).

Thesis (M.S.)--Ohio University, November, 2001. / Title from PDF t.p.