Lichens have been used extensively and with considerable success as bioindicators of atmospheric pollution in North America and Europe for more than thirty years. Little research has followed in tropical and subtropical regions where population growth is rapid and environmental pressures unprecedented. However, taxa used as bioindicators in other studies and/or taxa having this potential, occur naturally in Central Florida. A new potential major source of pollution, the coal-fired Curtis H. Stanton Energy Center, is about to begin operation providing the opportunity to determine the extent of impact. Therefore, lichen monitoring sites have been established and the collection of baseline data reflecting species diversity, frequency, overall cover and vitality has been accomplished. These locations will be preserved for future monitoring activities. Voucher specimens and photographic documentation of sample populations have been deposited in the herbarium of the University of Central Florida.

An experimental test system was designed to simulate the operating conditions found in nonslagging coal gasifiers. The reaction products that form when refractory linings in coal gasifiers are exposed to alkali impurities (sodium or potassium) were experimentally determined. Analysis of selected physical and chemical properties of the reaction products, which typically form between the alkali and the refractory will lead to a better understanding of the mechanisms behind refractory failures associated with alkali attack. The reaction products sodium aluminate (Na₂O·Al₂O₃), N₂C₃A₅ (2Na₂O·3CaO·5A1₂O₃), nepheline (Na₂0·Al₂0₃·2SiO₂), potassium aluminate, (K₂Oâ·Al₂0₃), and kaliophilite (K₂O·Al₂0₃·2Si0₂) were synthesized and their solubility in water and coefficients of linear thermal expansion were: measured. Of the compounds tested, the formation of potassium aluminate would be the most detrimental to the gasifier lining. The linear thermal expansion of potassium aluminate was 2.05% from room temperature to 800°C, which was twice as large as the other compounds. Potassium aluminate also possessed the highest solubility in water which was 8.893/L at 90°C. / Master of Science

The first conclusion that can be drawn from these results is the extreme variation in the size distribution of the particles of the material. Table nine shows the maximum, average and minimum percents of each size found in the roof shales, and table ten shows the same factors for the floor clays. From the reported answers to question A we can also see the wide range of opinion concerning roof shales. Of those materials classed as slate, the sand size varied from 1 to 64 percent, while the material reported as draw-slate fell between these limits with a range of sand size from 3 to 38 percent. / Master of Science

This thesis is concerned with the study of typical coal flow operations in the coal industry, with a concentration on the blending and distribution problems. Westmoreland Coal Company at Big Stone Gap, VA serves as the basis for our study. The problem here is to determine decisions and schedules for coal shipment to silos, cleaning and blending operations at silos, and the subsequent shipment of coal to customers over a multi-period time horizon, so as to satisfy the demand at a minimum operational cost. Three linear programming models of varying complexity and capability are developed to meet this objective. The final product is a computer-based decision tool which will serve as a mechanism for implementing cost-effective decisions in light of complex variations in production, ore quality, and demand requirements over time. The models can be used to plan future growth and capital investment decisions, as well as to study the effect of various policies, by testing the sensitivity, feasibility, and the cost of system operations under different perturbations of system configuration, data, and demand specifications. Real operational data from the Westmoreland Coal Company is used for testing purposes. / Master of Science

Both active and residual mine subsidence resulting from underground coal mining have caused surface damage to land and structures. A method of subsidence mitigation successfully used abroad, and to a much lesser extent in U.S. coal mines, is backfilling. In addition to the possible benefits of subsidence mitigation, backfilling has the potential to increase coal recovery, enhance ventilation control, and to minimize mine fires. Backfilling can also be used as a means of mine refuse disposal, provided the refuse is a suitable fill material. A Iiterature review has been made of the various backfilling practices and stowing materials that have been used in both underground hardrock and coal mines. The mechanics of fill support were also reviewed, as well as how the physical properties of a stowing material affect its ability to provide ground support. Based on this review, a testing program was conducted to examine properties of coal refuse which are pertinent to its placement and its ability to act as a ground support material. The testing program consisted of the slake durability test, plasticity test (Atterberg's Limits), grain-size analysis, standard Proctor compaction test, falling-head permeability test, and triaxial compression test. Based on the geotechnical properties of the refuse which was sampled, it was determined to be inadequate as a backfill material. / Master of Science

A novel technique for selectively coagulating and separating coal from dispersed mineral matter has been developed at Virginia Tech. The process, which is known as Selective Hydrophobic Coagulation (SHC), differs from oil agglomeration, shear or polymer flocculation, and electrolytic coagulation processes in that it does not require reagents or additives to induce the formation of coagula. In most cases, simple pH control is all that is required to (i) induce the coagulation of coal particles and (ii) effectively disperse particles of mineral matter. If the coal is oxidized, a small dosage of reagents may be used to enhance the coagulation process. During the SHC development, it was discovered that the hydrophobic coagula were very difficult to separate from dispersed mineral matter due to their very small size and their susceptibility to breakage. Using the SHC technique, an evaluation of new methods for coagula recovery was conducted. In this effort, several methods for improving the separation of the coal coagula from dispersed mineral matter were examined. These included lamella thickening, centrifugal sedimentation, vacuum filtration, drum screening, and froth flotation. Each separation method was optimized using statistically-designed test matrices to determined the best separation method based on overall process performance. The thickener was found to be the best method for separating hydrophobic coagula from dispersed mineral matter based on overall process performance (e.g., recovery and grade), unit capacity, and engineering feasibility. Further testing of the thickener separation unit was conducted in an attempt to improve the process performance and the unit throughput. / Master of Science

In recent years supercritical fluid chromatography has gained attention as an alternative technique to high performance liquid chromatography for the analyses of nonvolatile or thermally labile compounds, whose analysis with gas chromatography is impossible. The work presented here demonstrates a system that allows supercritical fluid extraction of the sample with subsequent direct introduction of a fraction of. this extract onto the column for analysis with supercritical fluid chromatography. Such a procedure has several inherent advantages to traditional sampling, where extraction or dissolution of the sample is done in a liquid. A valving scheme is described to accomplish this task and is evaluated for use with several different samples, including fuels and food products, with direct comparisons made between traditional sampling and direct on-line extraction. In most cases, the chromatograms were very similar, however later eluting components were sometimes lower in concentration with this method when compared to traditional sampling techniques. The apparatus was demonstrated in the analysis of high boiling coal derived material. Analysis of this material is accomplished by preliminary class separation with subsequent supercritical fluid extraction and analysis by packed column supercritical fluid chromatography. Detection included variable wavelength UV and FTIR spectrometry. The coal derived products studied were taken from a bench scale coal liquefaction reactor, in which the same catalyst was used for twenty-five consecutive days. The changes that occur as the catalyst decays were determined chromatographically for a portion of the high boiling products. The changes were noted best in the aromatic fraction analysis, where a trend towards molecules with higher numbers of condensed rings was observed as the catalyst decayed. / Master of Science

The surface properties of coal greatly affect its use in industrial processes such as gasification, liquefaction and the use of coal slurries. In addition, such processes also involve reagent penetration into coal pores and the oxidative state of the coal surface. Reagent penetration into coal was examined by determining the heat and kinetics of immersion of Pocahontas No. 3 coal in water, methanol, a series of n-alkanes, and several cyclic and heterocyclic hydrocarbons. Results indicate that the heat of immersion is sensitive to the carbon chain length of the wetting liquid and its ability to hydrogen bond to coal. The time of immersion is insensitive to carbon chain length but is increased by the presence of nitrogen in a cyclic hydrocarbon. The oxidation of both unextracted and extracted coal at 3200C was followed by immersional measurements in water. The heat of immersion increased rapidly with oxidation time, leveling off after 3 hours of oxidation. Extraction with methanol or pyridine prior to oxidation and immersion lowered the time of immersion in water compared to the unextracted case. The oxidation of coal was also followed by x-ray photoelectron spectroscopy (XPS). The XPS oxygen/carbon ratios correlated linearly with the heats of immersion for the extracted, oxidized coals. Thus, XPS was shown to be a useful ancillary technique to heat of immersion for the study of coal surfaces. / Master of Science

none available / Master of Science

This project investigates the development of Western Man's relationship with nature by comparing and contrasting it with the relationship that Native Cultures, particularly Native American Cultures have with nature. This reveals Western Man's reliance on the concept of objectivity and the resultant objectification of the natural world. In so doing Western Man has put himself apart from the rest of the world, somehow above it. Although I do not argue that this is wholly unjust, I do argue that it has resulted in a loss of an essential component of the human experience. Creative Participation is identified as a way to bring together some of the lessons of the Native communities with the existing knowledge of Western Society. This knowledge is then applied to the practical problem of Mine Land Reclamation in Southern West Virginia. Creative Participation, at its heart, is a way to reconnect man with the reality of his connection to the rest of the world, rather than his separation and control of it. / Master of Landscape Architecture