Coal Mine Safety and Health

[Excerpt] Safety in the coal mining industry is much improved compared to the early decades of the twentieth century, a time when hundreds of miners could lose their lives in a single accident and more than 1,000 fatalities could occur in a single year. Fatal injuries associated with coal mine accidents fell almost continually between 1925 and 2005, when they reached an all-time low of 23. As a result of 12 deaths at West Virginia’s Sago mine and fatalities at other coal mines in 2006, however, the number of fatalities more than doubled to 47. Fatalities declined a year later to 33, which is comparable to levels achieved during the late 1990s. In addition to the well above-average fatal injury rates they face, coal miners suffer from occupationally caused diseases. Prime among them is black lung (coal workers’ pneumoconiosis, CWP), which still claims about 1,000 fatalities annually. Although improved dust control requirements have led to a decrease in the prevalence of CWP, there is recent evidence of advanced cases among miners who began their careers after the stronger standards went into effect in the early 1970s. In addition, disagreement persists over the current respirable dust limits and the degree of compliance with them by mine operators. In the wake of the January 2006 Sago mine accident, the U.S. Department of Labor’s Mine Safety and Health Administration (MSHA) was criticized for its slow pace of rulemaking earlier in the decade. MSHA standard-setting activity quickened starting later that year, however, after enactment in June of the Mine Improvement and New Emergency Response Act (MINER, P.L. 109-236). The MINER act, the first major amendment to federal mine safety law since 1977, emphasized factors thought to have played a role in the Sago disaster (e.g., emergency oxygen supplies, post-accident communication and tracking systems, deployment of rescue teams) and imposed several rulemaking deadlines on MSHA. Accordingly, the agency published final regulations on emergency mine evacuation in December 2006, civil penalties in March 2007, and rescue teams as well as asbestos exposure in February 2008. Some policymakers remain dissatisfied with MSHA’s performance. These sentiments most recently led to House passage, in January 2008, of the Supplemental Mine Improvement and New Emergency Response Act (S-MINER, H.R. 2768). It incorporates language from the Miner Health Enhancement Act (H.R. 2769), such as requiring MSHA to adopt as mandatory exposure limits the voluntary limits (to chemical hazards, for example) recommended by the National Institute for Occupational Safety and Health. S-MINER also requires MSHA to more closely review and monitor operator plans that include retreat mining, the practice used at Utah’s Crandall Canyon mine where six miners and three rescuers lost their lives in 2007. The President has said he will veto S-MINER as passed by the House. In light of rulemaking activity required this year by the MINER act and the Consolidated Appropriations Act, 2008 (P.L. 110-161), MSHA asked the Occupational Safety and Health Administration for assistance. Congress increased MSHA’s appropriation between FY2007 ($302 million) and FY2008 ($334 million). The Administration’s FY2009 budget request for MSHA is $332 million

Measurement of radon concentrations at Super-Kamiokande

Radioactivity from radon is a major background for observing solar neutrinos at Super-Kamiokande. In this paper, we describe the measurement of radon concentrations at Super-Kamiokande, the method of radon reduction, and the radon monitoring system. The measurement shows that the current low-energy event rate between 5.0 MeV and 6.5 MeV implies a radon concentration in the Super-Kamiokande water of less than 1.4 mBq/m$^3$.Comment: 11 pages, 4 figure

Calibration of Super-Kamiokande Using an Electron Linac

In order to calibrate the Super-Kamiokande experiment for solar neutrino measurements, a linear accelerator (LINAC) for electrons was installed at the detector. LINAC data were taken at various positions in the detector volume, tracking the detector response in the variables relevant to solar neutrino analysis. In particular, the absolute energy scale is now known with less than 1 percent uncertainty.Comment: 24 pages, 16 figures, Submitted to NIM

Evaluating the Eleventh District's Beige Book

In this study, Nathan Balke and Mine Yucel ask whether the Eleventh Federal Reserve District's Beige Book description contains timely information about economic activity within the District. They examine whether the Beige Book description tracks current Texas real gross state product (GSP) growth and current Texas employment growth. They also study whether the Beige Book has information about growth not present in other regional indicators that would have been available to analysts at the time of the Beige Book's release. They find that both the Beige Book summary and the average across sectors reflect Texas GSP and employment growth very well. These two measures of the Beige Book also have predictive content for one quarter ahead GSP growth. Balke and Yucel also find that the Eleventh District's Beige Book has information content for Texas economic activity over and above other state economic indicators such as Texas employment growth, personal income, or sectoral employment growth. Because the Beige Book is released at least one month earlier than employment data and at least two years before GSP data, its timeliness makes it a good tool for current regional economic analysis.Employment (Economic theory) ; Unemployment ; Economic indicators

The larval mine of Stigmella lappovimella (Svensson, 1976) on Salix lapponum (L.) (Lepidoptera, Nepticulidae)

The larval mine of Stigmella lappovimella in leaves of Salix lapponum of different host leaf thickness is described and differences between the mine and the mines of Stigmella salicis on Salix caprea and Stigmella zelleriella on Salix repens are noted. The best diagnostic characters differentiating the mine of S. lappovimella from the two others was the almost unbroken frass line in the first half and the limited frass particle dispersion in the second half of the mine. Wing length was also measured and a small but statistically significant difference was observed between S. lappovimella and S. zelleriella

DDASaccident295

After replacing the pin, he turned the mine over and put pressure on the base of the mine to try to force it open. The mine detonated. He lost the hand that was holding the mine and had extensive damage to his leg(s) under the table

Nematic elastomers with aligned carbon nanotubes: new electromechanical actuators

We demonstrate, for the first time, the large electromechanical response in nematic liquid crystalline elastomers filled with a very low (~0.01%) concentration of carbon nanotubes, aligned along the nematic director at preparation. The nanotubes create a very large effective dielectric anisotropy of the composite. Their local field-induced torque is transmitted to the rubber-elastic network and is registered as the exerted uniaxial stress of order ~1kPa in response to a constant field of order ~1MV/m. We investigate the dependence of the effect on field strength, nanotube concentration and reproducibility under multiple field-on and -off cycles. The results indicate the potential of the nanotube-nematic elastomer composites as electrically driven actuators

Projectile impact effects on a 50 psi plug type coal mine seal

The current lack of projectile damage criteria for mine seals is assessed to determine if criteria should be developed. Impact experiments were performed on a full-scale 50 psi mine seal to determine failure modes, dynamic stress state, and assess risk to existing operational mine seals. Test projectiles were selected from common underground coal mine items propelled by means of a black powder projectile generator. Projectile velocities attained in testing ranged from approximately 100 to 650 ft/s (30 to 200 m/s). Dynamic strain was measured on the non-impact face to derive the state of stress and estimate failure criteria. Penetration models were used to estimate depth of penetration and compared to empirical data. Finite element analysis impact simulation was compared with empirical data and a critical impact velocity for rigid body projectiles of 20 to 30 lb (9 to 14 kg) was estimated to be in the range of 550 to 600 ft/s (168 to 183 m/s). Damage to the mine seal was observed and compared with numerical simulation to assess the need for defined projectile damage criteria to mine seals --Abstract, page iii

INVESTIGATING THE EFFECT OF STRESS, WETTING, AND COMPACTION ON SETTLEMENT POTENTIAL OF MINE SPOILS

Strip mining in Kentucky has left large areas of land that could potentially be used for business and housing developments. However, the mine spoils underlying these areas are prone to severe differential settlement due to a variety of factors. Mine spoil from the Gateway Business Park in Jenkins, Kentucky was used for a series of laboratory tests to develop relationships between shear wave velocity, confining stress, compaction energy, and dry unit weight to develop a method to assess settlement potential. It was found that a stress-corrected shear wave velocity of greater than 275 ft/s/psi0.25 typically indicated dry mine spoil, and less than 275 ft/s/psi0.25 typically indicated wet mine spoil. Equations were developed to predict the amount of settlement of a mine spoil profile based on the load, the mine spoil lithology, and the shear wave velocity of the mine spoil. With regards to compaction, it was found that if the mine spoil was compacted to at least 120 pcf (18.8 kN/m3), or a void ratio of 0.45 or less, the mine spoil would suffer little to no volume change when wetted. The results provided herein form the basis of a methodology for screening mine spoil sites for development based on settlement potential