Download or read book Evaluation of Explosion Resistant Seals Stoppings and Overcast for Ventilation Control in Underground Coal Mining written by Eric S. Weiss and published by Createspace Independent Pub. This book was released on 2002 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report discusses the construction techniques, testing methods, and explosion test data collected for the pumpable cementitious seals; the seal, stopping, and overcast designs for the Australian program; and the Packsetter preloaded solid-concrete-block seal.
Download or read book Explosion Pressure Design Criteria for New Seals in U S Coal Mines written by M. J. Sapko and published by . This book was released on 2007 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seals are barriers constructed in underground coal mines throughout the United States to isolate abandoned mining panels or groups of panels from the active workings. Historically, mining regulations required seals to withstand a 140-kPa (20-psig) explosion pressure. However, the Mine Improvement and New Emergency Response Act ("MINER Act") requires the Mine Safety and Health Administration (MSHA) to increase this design standard by the end of 2007. This report provides a sound scientific and engineering justification to recommend a three-tiered explosion pressure design criterion for new seals in coal mines in response to the MINER Act. Much of the information contained in this report also applies to existing seals. Engineers from the National Institute for Occupational Safety and Health (NIOSH) examined seal design criteria and practices used in the United States, Europe, and Australia and then classified seals into their various applications. Next, the engineers considered various kinds of explosive atmospheres that can accumulate within sealed areas and used thermodynamic calculations and simple gas explosion models to estimate worst-case explosion pressures that could impact seals. Three design pressure-time curves were developed for the dynamic structural analysis of new seals under the conditions in which those seals may be used: unmonitored seals where there is a possibility of methane-air detonation or high-pressure nonreactive shock waves and their reflections behind the seal; unmonitored seals with little likelihood of detonation or high-pressure nonreactive shock waves and their reflections; and monitored seals where the amount of potentially explosive methane-air is strictly limited and controlled. Figure I is a simple flowchart that illustrates the key decisions in choosing between the monitored or unmonitored seal design approaches and the three design pressure-time curves. For the first condition, an unmonitored seal with an explosion run-up length of more than 50 m (165 ft), the possibility of detonation or high-pressure nonreactive shock waves and their reflections exists. The recommended design pressure-time curve rises to 4.4 MPa (640 psig) and then falls to the 800-kPa (120-psig) constant volume (CV) explosion overpressure. For unmonitored seals with an explosion run-up length of less than 50 m (165 ft), the possibility of detonation or high-pressure nonreactive shock waves and their reflections is less likely. A less severe design pressure-time curve that simply rises to the 800-kPa (120-psig) CV explosion overpressure may be employed. For monitored seals, engineers can use a 345-kPa (50-psig) design pressure-time curve if monitoring can ensure that (1) the maximum length of explosive mix behind a seal does not exceed 5 m (16 ft) and (2) the volume of explosive mix does not exceed 40% of the total sealed volume. Use of this 345-kPa (50-psig) design pressure-time curve requires monitoring and active management of the sealed area atmosphere. These design pressure-time curves apply to new seal design and construction. NIOSH engineers used these design pressure-time curves along with the Wall Analysis Code (WAC) from the U.S. Army Corps of Engineers and a simple plug analysis to develop design charts for the minimum required seal thickness to withstand each of these explosion pressure-time curves. These design charts consider a range of practical construction materials used in the mining industry and specify a minimum seal thickness given a certain seal height. Results of these analyses show that resistance to even the 4.4-MPa (640-psig) design pressure time curve can be achieved using common seal construction materials at reasonable thickness, demonstrating the feasibility and practical applications of this report. Engineers can also use other structural analysis programs to analyze and design seals by using the appropriate design pressure-time curve for the structural load and a design safety factor of 2 or more. Finally, this report also provides criteria for monitoring the atmosphere behind seals. NIOSH will continue research efforts to improve underground coal mine sealing strategies and to prevent explosions in sealed areas of coal mines. In collaboration with the U.S. National Laboratories, NIOSH will further examine the dynamics of methane and coal dust explosions in mines and the dynamic response of seals to these explosion loads. This upcoming project seeks to better understand the detonation phenomena and simple techniques to protect seals from transient pressures. Additional work will include field measurements of the atmosphere within sealed areas. Successful implementation of the seal design criteria and the associated recommendations in this report for new seal design and construction should significantly reduce the risk of seal failure due to explosions in abandoned areas of underground coal mines.
Download or read book The State of Mine Safety and Health written by United States. Congress. Senate. Committee on Health, Education, Labor, and Pensions and published by . This book was released on 2006 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of Society for Mining Metallurgy and Exploration Inc written by and published by . This book was released on 1990 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strengthening Existing 20 Psi Mine Ventilation Seals with Carbon Fiber Reinforced Polymer Reinforcement written by Eric S. Weiss and published by Createspace Independent Pub. This book was released on 2008-01-31 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Mining Association and the Mine safety and Health Administration requested that the National Institute for Occupational Safety and Health (NIOSH) conduct full-scale evaluations of a recently developed carbon fiber-reinforced polymer (CFRP) reinforcement technique for upgrading existing mine ventilation seals to withstand an explosion pressure of 50 psi or greater. The evaluation was conducted in the NIOSH Pittsburgh Research Laboratory's Lake Lynn Experimental Mine (LLEM). The purpose of the evaluation was to determine the blast resistance of the CFRP reinforcement technique, designed to increase the strength of two types of existing 20-psi-rated in situ mine ventilation seals.
Download or read book Compendium of Structural Testing Data for 20 Psi Coal Mine Seals written by Karl Zipf and published by Createspace Independent Pub. This book was released on 2009-08-31 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents nearly all structural data available from explosion tests of 20-psi mine ventilation seals and concrete-block ventilation stoppings that were conducted by the NIOSH during 1997-2008. Although the seals tested were designed to meet the former federal 20-psi pressure design standard, the structural information contained herein on these seal tests will facilitate the analysis and design of coal mine seals that meet the new explosion pressure criteria of 50 and 120 psi as set forth in the Mine safety and health Administration's final rule on “Sealing of Abandoned Areas.”
Download or read book A Story of Impact written by National Institute for Occupational Safety and Health and published by . This book was released on 2010 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Seals, which are used in underground coal mines throughout the U.S. to isolate abandoned mining areas from the active workings, were required to withstand a 140-kPa (20-psig) explosion pressure under mining regulations prior to the Sago Mine disaster in 2006. The failure of seals at Sago prompted sweeping regulatory changes that were initiated with the passage of the Mine Improvement and New Emergency Response Act (MINER act), which required MSHA to increase the seal design standard by the end of 2007. Based on sound scientific and engineering justification, NIOSH researchers developed explosion pressure design criteria for new seal designs and for monitoring the atmosphere behind seals to protect miners from blast effects and toxic gases produced by contained explosions. This information was published in July 2007. In 2008, MSHA issued the final rule for mine seals based, in part, on the information contained in this NIOSH report. The final rule states that seals must withstand 345 kPa (50 psig) if the sealed area atmosphere is monitored and maintained inert, 828 kPa (120 psig) if the sealed area atmosphere is not monitored, and greater than 828 kPa (120 psig) if the sealed area atmosphere is not monitored and certain conditions exist that might lead to higher explosion pressures. From 2001 to 2007, the NIOSH Office of Mine Safety and Health Research conducted studies to develop alternative ways to determine the adequacy of coal mine seals. The researchers compared full-scale explosion testing within the Lake Lynn Experimental Mine to full-scale hydrostatic testing within a chamber using water to load seals to pressure. Researchers found that gradually applying water pressure to twice the expected explosion pressure was equivalent to the effects created by the rapid increase in pressure loading that results from confined explosions. These hydrostatic tests provided stress-strain measurements, determined the ultimate strength of seals, and demonstrated that hydrostatic testing of mine seals was a timely and cost-effective alternative to full-scale explosion testing. Results of these studies should be used with the testing of mine ventilation seals. NIOSH Recommendations: 1. Use hydrostatic testing of mine seals in place of or in conjunction with full-scale explosion testing as a means to validate engineering calculations and models. 2. Use empirical resistance data from the hydrostatic testing to improve or validate design codes. These new data should be considered when using or evaluating design codes. 3. Test seals under static load at least twice the explosion design pressure when performing hydrostatic tests. 4. Conduct additional studies to further refine and quantify the response. 5. Utilize only design codes validated by testing for mine seal design." - NIOSHTIC-2
Download or read book Evaluation of the Transverse Load Capacity of Block Stoppings for Mine Ventilation Control written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compendium of Structural Testing Data for 20 Psi Coal Mine Seals written by Department of Health and Human Services and published by CreateSpace. This book was released on 2013-10 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents nearly all structural data available from explosion tests of 20-psi mine ventilation seals and concrete-block ventilation stoppings that were conducted by the National Institute for Occupational Safety and Health during 1997–2008. Although the seals tested were designed to meet the former federal 20-psi pressure design standard, the structural information contained herein on these seal tests will facilitate the analysis and design of coal mine seals that meet the new explosion pressure design criteria of 50 and 120 psi as set forth in the Mine Safety and Health Administration (MSHA)'s final rule on “Sealing of Abandoned Areas.” The seal testing data are organized into six broad categories of seal structures based on the materials used and the construction method for those 20-psi seals: 1. Concrete like materials with steel reinforcement and reinforcement bar anchorage to rock; 2. Pumpable cementitious materials of varying compressive strengths with no steel reinforcement and no hitching; 3. Articulated structures such as solid-concrete-block seals and ventilation stoppings made of solid and hollow-core concrete blocks; 4. Polymer and aggregate materials without hitching; 5. Wood-crib-block seals with or without hitching; 6. Articulated structures such as lightweight blocks with or without hitching. This report organizes and presents the applied loading or P-t curves and, when available, the measured displacement-time (D-t) curves for 44 different seal structures tested prior to 2006 when the former 20-psi explosion pressure design criterion applied to mine seals. Also included in this data set are the applied loading P-t curves and response D-t curves for eight different ventilation stoppings constructed with solid or hollow-core concrete blocks. These structural test results against the stop-pings are included as supplemental information pertinent to the design of seals that incorporate concrete blocks in some capacity.
Download or read book Explosion resistant Seals for Underground Coal Mines June 1999 written by and published by . This book was released on 1999 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ventilation Questions and Answers written by and published by . This book was released on 1992 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Injury Experience in Coal Mining written by and published by . This book was released on 1949 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Royal Commission on the Pike River Coal Mine Tragedy written by New Zealand. Royal Commission on the Pike River Coal Mine Tragedy and published by . This book was released on 2012 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Details the tragic events at Pike River Coal Mine on 19 November that resulted in the loss of 29 lives. Propsoals and recommendations for improvements to the safety of people working in mines.
Download or read book Blindsight written by Peter Watts and published by Macmillan. This book was released on 2006-10-03 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hugo and Shirley Jackson award-winning Peter Watts stands on the cutting edge of hard SF with his acclaimed novel, Blindsight Two months since the stars fell... Two months of silence, while a world held its breath. Now some half-derelict space probe, sparking fitfully past Neptune's orbit, hears a whisper from the edge of the solar system: a faint signal sweeping the cosmos like a lighthouse beam. Whatever's out there isn't talking to us. It's talking to some distant star, perhaps. Or perhaps to something closer, something en route. So who do you send to force introductions with unknown and unknowable alien intellect that doesn't wish to be met? You send a linguist with multiple personalities, her brain surgically partitioned into separate, sentient processing cores. You send a biologist so radically interfaced with machinery that he sees x-rays and tastes ultrasound. You send a pacifist warrior in the faint hope she won't be needed. You send a monster to command them all, an extinct hominid predator once called vampire, recalled from the grave with the voodoo of recombinant genetics and the blood of sociopaths. And you send a synthesist—an informational topologist with half his mind gone—as an interface between here and there. Pray they can be trusted with the fate of a world. They may be more alien than the thing they've been sent to find. At the Publisher's request, this title is being sold without Digital Rights Management Software (DRM) applied.
Download or read book Pentagon 9 11 written by Alfred Goldberg and published by Office of the Secretary, Historical Offi. This book was released on 2007-09-05 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive account to date of the 9/11 attack on the Pentagon and aftermath, this volume includes unprecedented details on the impact on the Pentagon building and personnel and the scope of the rescue, recovery, and caregiving effort. It features 32 pages of photographs and more than a dozen diagrams and illustrations not previously available.
Download or read book Pathology of the Lungs E Book written by Bryan Corrin and published by Elsevier Health Sciences. This book was released on 2011-02-25 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an emphasis on practical diagnostic problem solving, Pathology of the Lungs, 3rd Edition provides the pulmonary pathologist and the general surgical pathologist with an accessible, comprehensive guide to the recognition and interpretation of common and rare neoplastic and non-neoplastic lung conditions. The text is written by two authors and covers all topics in a consistent manner without the redundancies or lapses that are common in multi-authored texts. The text is lavishly illustrated with the highest quality illustrations which accurately depict the histologic, immunohistochemical and cytologic findings under consideration and it is supplemented throughout with practical tips and advice from two internationally respected experts. The user-friendly design and format allows rapid access to essential information and the incorporation throughout of relevant clinical and radiographic information makes it a complete diagnostic resource inside the reporting room. Approximately 1,000 high quality full color illustrations.Provides the user with a complete visual guide to each specimen and assists in the recognition and diagnosis of any slide looked at under the microscope. Comprehensive coverage of both common and rare lung diseases and disorders. One stop consultation resource for the reporting room or study, no need to go further to get questions answered. Clinical background and ancillary radiographs incorporated throughout.Provides the user with all of the necessary diagnostic tools to make a complete and accurate pathologic report. Practical advice and tips from two of the world’s recognized experts. Provides the trainee and general surgical pathologist with time saving diagnostic clues when dealing with difficult specimens. Consistent and uniform approach incorporated for each disease and disorder (Etiology, pathogenesis, clinical features, pathologic features, differential diagnosis) User-friendly format enables quick and easy navigation to the key information required. Extensive use of summary tables, charts and graphs throughout the text. Helps simplify and clarify complex concepts and facilitates “at a glance comparisons between entities. Extensive reference list highlights landmark articles as well as including most up-to-date citations. Directs the trainee and practitioner to the most recent and authoritative sources for further reading and investigation
Download or read book Brittle Power written by Amory B. Lovins and published by . This book was released on 1982 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
