32 research outputs found

    Coal dust explosibility meter evaluation and recommendations for application

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    "This report details the results of a NIOSH investigation on the ability of the Coal Dust Explosibility Meter (CDEM) to accurately predict the explosibility of samples of coal and rock dust mixtures collected from underground coal mines in the U.S. The CDEM, which gives instantaneous results in real time, represents a new way for miners and operators to assess the relative hazard of dust accumulations in their mines and the effectiveness of their rock dusting practices. The CDEM was developed by the National Institute for Occupational Safety and Health (NIOSH) and successfully underwent national and international peer review. The intention of the device is to assist mine operators in complying with the Mine Safety and Health Administration (MSHA) final rule 30 CFR* 75.403, requiring that the incombustible content of combined coal dust, rock dust, and other dust be at least 80% in underground areas of bituminous coal mines. As a final step towards commercialization of the CDEM, and to evaluate the performance of the device as a potential compliance tool, NIOSH undertook an extensive cooperative study with MSHA. This study, completed in 2009-2010, involved field use of the CDEM within MSHA's 10 bituminous coal districts. As part of their routine dust compliance surveys in these districts, MSHA inspectors collected sample coal and rock dust mixtures, field testing these samples for explosibility with the CDEM. Samples were then sent to the MSHA National Air and Dust Laboratory at Mt. Hope, WV, for parallel testing, first using a drying oven to determine the moisture followed by the traditional low temperature ashing (LTA) method. The LTA method determines explosibility of a coal and rock dust sample in a laboratory by heating the mixture to burn off the combustible material. The results, when combined with the moisture, are reported as total incombustible content (TIC). If the TIC is . 80%, the sample is deemed to be nonexplosible and compliant with 30 CFR 75.403. In the field component of this study, MSHA's use of the CDEM indicated that 30% (175) of the 591 samples collected were explosible. NIOSH was able to obtain and remeasure 297 samples, and 97% of those identified by the CDEM as being explosible (27% of samples) or nonexplosible (73% of samples) correlated with the results of the subsequent lab analysis using the LTA method. Of the remaining 3% where there were differences between the field and laboratory methods, subsequent NIOSH evaluation attributed these differences to the variability (incomplete mixing, inadequate drying of the sample, the particle size of the rock dust and/or coal dust) of the samples being analyzed, the retained moisture in those samples, and the inherent ash in the coal. In considering these results and comparing the CDEM field measurements to the LTA laboratory measurements, it is important to understand the fundamental distinctions between the two methods. The determination of TIC by the LTA method is not itself a direct measure of explosibility, but a surrogate that calculates a single parameter associated with full-scale experimental results. This method is not based on particle size and treats all particles equally regardless of the size. In contrast, the CDEM utilizes a different approach, using optical reflectance to determine the ratio of rock dust to coal dust in a mixture, with full-scale experiments on flame propagation having already demonstrated the effects of varying the coal dust particle sizes and incombustible concentrations on the explosible vs. nonexplosible dust mixtures. A final important distinction between the two methods is that the CDEM offers real-time measurements of the explosion propagation hazard within a coal mine entry, allowing for immediate identification and mitigation of the problem, while the results from the traditional LTA method are not known for days or weeks after a sample is collected, allowing for the deficiency in rock dust to continue. The conclusions of this study strongly support the field use of the CDEM to measure the explosibility of coal and rock dust mixtures, to more effectively improve the onsite adequacy of rock dusting for explosion prevention. Mine operators could use the CDEM on a regular basis to ensure that their rock dusting practices are achieving inertization requirements and meeting the intent of 30 CFR 75.403. MSHA inspectors could use the CDEM as a tool to immediately identify onsite explosibility hazards and initiate corrective action. A critical issue to both the LTA and the CDEM analysis methods is that the results are dependent on representative samples being collected for analysis." - NIOSHTIC-2Executive summary -- Introduction -- Background on coal dust and explosibility testing -- CDEM 0peration -- Comparison of laboratory results and CDEM results -- Joint study between NIOSH and MSHA -- Results and discussion -- GREEN measurements -- RED/YELLOW measurements -- Conclusions from the NIOSH study -- Commercial CDEM development -- Calibration and programming of the commercial CDEM -- Commercial CDEM changes based on potential customer concerns -- The Commercial CDEM as a verification and compliance tool -- NIOSH recommendations -- Acknowledgments -- References -- APPENDIX A: CDEM design -- APPENDIX B: CDEM training -- APPENDIX C: Prototype CDEM calibration and testing procedures used in the joint study -- APPENDIX D: Particle size effect -- APPENDIX E: MSHA inspector questions and commentsMarcia L. Harris, Michael J. Sapko, Floyd D. Varley, and Eric S. Weiss"August 2012."Also available via the World Wide Web.Includes bibliographical references (p. 25-26)

    Mitigation of flooding and cyclone hazard in Orissa, India

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    Storm surges generated by the strong tangential wind stressesand normal atmospheric pressure gradients at the sea surface due to tropical cyclones (TC"S)have been studied with the goal of detecting any significant and systematic changes due to climatechange. Cyclone and storm surge data for the 19th and 20th centuries for the Bay of Bengalcoast of the state of Orissa in India are available to varying degrees of quality and detail,the data being more scientific since the advent of the India Meteorological Department in 1875.Based on more precise data for the period 1971 to 2000, statistical projections have been madeon the probable intensities of tropical cyclones for various return periods. The super cyclone ofOctober 29, 1999 (SC1999) appears to have a return period of about 50 years. The cyclones of1831, 1885 and possibly the one in 1895 could have been super cyclones. During the 19th century,there were 72 flooding events associated with cyclones, whereas in the 20th century therewere only 56 events. There was no observational evidence to suggest that there was an increaseeither in the frequency or intensity of cyclones or storm surges on the coast of Orissa. However,the impact of cyclones and surges is on the increase due to increase of population and coastal infrastructure

    The SpikerBox: A Low Cost, Open-Source BioAmplifier for Increasing Public Participation in Neuroscience Inquiry

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    Although people are generally interested in how the brain functions, neuroscience education for the public is hampered by a lack of low cost and engaging teaching materials. To address this, we developed an open-source tool, the SpikerBox, which is appropriate for use in middle/high school educational programs and by amateurs. This device can be used in easy experiments in which students insert sewing pins into the leg of a cockroach, or other invertebrate, to amplify and listen to the electrical activity of neurons. With the cockroach leg preparation, students can hear and see (using a smartphone oscilloscope app we have developed) the dramatic changes in activity caused by touching the mechanosensitive barbs. Students can also experiment with other manipulations such as temperature, drugs, and microstimulation that affect the neural activity. We include teaching guides and other resources in the supplemental materials. These hands-on lessons with the SpikerBox have proven to be effective in teaching basic neuroscience

    Women Artists and Leadership

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    Art is a human endeavor with complex associations to the spiritual, social, economic and political realms of societies throughout the ages. From the cave painting of ancient cultures through the artworks housed and guarded within institutional walls, the products of artists mirror the evolution of human imagination and chronicle the assignment of value and importance as determined by hegemonic interests. For centuries, the patriarchal hegemony disallowed the contributions of women artists, normalizing the point of view that their contributions were inconsequential to the history of art and to the movements that heralded each new breakthrough in vision. The civil rights movement and the women\u27s movement of the 19th and 20th Centuries marked a significant turning point in consciousness among women in the United States with the realization that there were undeniable parallels between discrimination based on race and discrimination based on gender. Similar strategies in the fight for individual rights and freedom of minorities could be applied toward championing rights and freedom for women. The social phenomenon of the women\u27s movement challenged the status quo as women sought redress for the discrimination rampant, among other arenas, in the arts. Studies have shown that discrimination against women in the visual arts has been historically virulent, but current research lacks studies specific to the strategies and skills contemporary women have used to engage in careers in the visual arts despite adversity. As the visual arts represent not only a vocational choice but also a rarified arena of power and wealth, it is important to identify means by which longevity and achievement in the visual arts can be realized. This paper hypothesizes that in order to survive in the visual V arts women have had to be leaders. For the purposes of this research study, leadership is defined using the Augsburg College leadership development model and using change oriented models of leadership, including charismatic, transformational and visionary. The research applies leadership theory as a framework to understand the phenomenon of women artists achieving historic gains in the 1960s - 1980s. Lengthy interviews conducted with ten women artists provide depth in understanding the experiences and points of view of individuals whose vocational choices are in the visual arts. Research and interview results support the hypothesis that women artists sustaining vocations in the visual arts embody leadership attributes and qualify as leaders according to contemporary leadership theory. Final speculations about the importance of art and the importance of women\u27s leadership in the visual arts are discussed in terms of the potential for adaptive change and the transformation needed to meet human needs in a pluralistic, global economy

    Berkeley's Immaterialism. By A. A. Luce (Thomas Nelson & Sons, Ltd. Price 6s.)

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