Dust generation at an underground coal mine working face continues to be a health and safety issue. Prolonged exposure to high concentrations of airborne respirable dust can cause a debilitating and often fatal respiratory disease called Black Lung. In addition, the deposition of float dust in mine return airways poses a serious safety hazard if not sufficiently diluted with inert rock dust. A localized methane explosion can transition into a self-propagating dust explosion. Since dust is a byproduct of various mining activities, such as cutting and loading, crushing, and transportation, the dust-related issues cannot be totally eliminated. However, the adverse health effects and safety concerns can be minimized if a significant amount of the generated dust is removed from the ventilation air by a mechanical device, such as a dust scrubber. Over the last three decades, flooded-bed dust scrubbers integrated into continuous miners have been successfully applied for capturing and removing airborne dust generated at the working face. According to the National Institute for Occupational Safety and Health (NIOSH), a flooded-bed scrubber can achieve more than 90% capture and cleaning efficiencies under optimum conditions. Although flooded-bed scrubbers have proven useful in the vast majority of cases, they have not yet been successfully applied to a longwall face. In the United States, numerous attempts have been made to reduce dust concentration at a longwall face through the application of a scrubber; but, none were successfully implemented. Encouraged by the successful use of a flooded-bed scrubber system at continuous miner faces, this research revisits the flooded-bed scrubber concept for a longwall shearer. For this investigation, a full-scale physical model of a Joy 7LS longwall shearer, modified with an integrated flooded-bed dust scrubber, was designed and fabricated at the University of Kentucky. The scope of work for this research was limited to capturing and cleaning dust generated near the shearer headgate drum only. The mock-up was transported to, and assembled in, the full-scale longwall dust gallery at the NIOSH Pittsburgh Research Laboratory (PRL). Tests were conducted to examine: (1) the effect of the scrubber on headgate-drum dust reduction and (2) the combined effect of the scrubber and splitter sprays on headgate drum dust reduction. Analysis of test results for the scrubber-alone condition indicates a significant dust reduction of up to 57% in the return airway and 85% in the test gallery walkway, whereas the combination of scrubber and splitter-arm sprays shows dust reduction of up to 61% and 96% in the return and walkway, respectively. These results indicate that a flooded-bed scrubber integrated into a longwall shearer can be used as a viable technique to reduce a large portion of airborne dust at a longwall face. Subsequently, a Computational Fluid Dynamics (CFD) model of the longwall gallery and shearer was developed and validated using the results of the experimental study. The CFD simulation results are in good agreement with the experimental results with a maximum of 9.7% variation. This validated CFD model can be used in future research to predict the effects of modifications to the scrubber system, including modifications to the scrubber inlet, to optimize the scrubber design, and to evaluate the effectiveness of adding a tailgate drum dust scrubber.

At the height of her career, Norma Shearer was the Queen of Metro-Goldwyn-Mayer and the First Lady of the silver screen. She starred in sixty films in twenty-three years, beginning her career as an extra in 1919 before dominating the box office in the 1930s and retiring in 1942. Shearer's husband was the ''Boy Wonder” producer, Irving Thalberg, the man responsible for overseeing many of the studio's greatest successes, although he preferred to remain uncredited for his work. When Shearer and Thalberg married in September 1927, they became Hollywood's golden couple. Throughout their nine-year marriage, rumors circulated that Shearer married Thalberg for the sake of her career, while Thalberg was accused of unfairly casting Shearer in key film roles for which other stars may have been better suited. In interviews that appeared in screen magazines, Shearer denied the validity of this gossip, and sources close to the couple often reported their marriage was full of love and happiness. Although Thalberg did not publicly deny any rumors, he assured bis colleagues that his casting choices did not result from favoritism. Shearer and Thalberg had great influence and power within the film industry, but studio executives felt they both held too much power-especially Thalberg. Using archival research from Los Angeles, California, and information collected from within the state of Florida, this thesis explores the rumors that circulated about Norma Shearer and Irving Thalberg and the couple's methods to reveal the truth. It provides the personal histories of both artists and an examination of the circumstances surrounding one of early Hollywood's most powerful couples. It was their success that brought about the rumors and the attempts to undermine their marriage.