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By R. V. Ramani, R. Stefanko, G. W. Luxbacher

Air Moving and Conditioning Association, Fan Application Manual Part 1, Fans and Systems, AMCA Publication 201, 1976a. Air Moving and Conditioning Association, Fan Application Manual Part 2, Troubleshooting, AMCA Publication 202, 1976b. Air Moving and Conditioning Association, Fan Application Manual Part 3, Field Performance Measurements, AMCA Publication 203, 1976c. Air Moving and Conditioning Association, Directory of Products Licensed to Bear the AMCA Certified Ratings Seal, Edition 27, August 1, 1975. Allan, A. L., Hollwey, J. R., and Maynes, J. H. B., Practical Field Surveying and Computations, American Elsevier Publishing Co., Inc., New York, 1968. American Society of Heating Refrigeration and Air Conditioning Engineers Std. 51-75, Air Moving and Conditioning Association Standard 210¬74, Laboratory Methods of Testing Fans for Rating. Anderson, T. C., and Nugent, J. W., "Mine Ventilation Pressure Differentials with a Programmable Hand Calculator," MESA Informational Report 1050, 1977. Atkinson, J. J., "On the Theory of the Ventilation of Mines," Trans. N. E. Inst., Vol. 3, 1854, pp. 118. Barnes, E. L. S., "Mine Ventilation Network Analysis," International Mine Ventilation Congress, Marshalltown, S. Africa, Sept., 1975. Boshkov, S, and Amontree, B., "How Operator Proximity Affects Anemometer Readings," Coal Age, Vol. 55, No. 5, 1950, pp. 85-56. Boshkov, S., and Wane, M. T., "Errors in Underground Air Measurements," Mining Engineering, Vol. 11, No. 7, November, 1955, pp. 1047-1053. Briggs, H., "The Underground Leakage of Air, Investigation of the Porosity Coefficient," Transaction of the Institution of Mining Engineers, Vol. 82, pp. 111-121. Brown, J. R., and Hinsley, F. B., "The Flow of Air in Bends and Straight Airways," Transaction of the Institution of Mining Engineers, Vol. 116, July, 1957, pp. 845-867. Burrows, J., "Measurement of Fan Pressures," Journal of the Mine Ventila¬tion Society of South Africa, Volume 27, No. 4, April 1974, pp. 57-63.

Jan 1, 1977

By G. L. Barlett, J .. D. Barry

Supernatant media of dust-exposed pulmonary alveolar macrophages (PAMs) were inactive in assays for both Interleukin-1 and fibroblast growth factors (FGF). We have begun to evaluate several factors that may interfere with dust-PAM interactions. To determine the effect of sterilization on the activity of dusts, PAMs were exposed to autoclaved dust, heat-sterilized dust or to dust that had not been heated. Supernatants from the first two groups were inactive in the FGF assay, but supernatant from PAMs exposed to unheated dusts stimulated growth of lung fibroblasts. Recent data have revealed that freshly crushed mineral dusts possess labile free radicals that are absent in dust that has been stored for more than a few days. Suspensions .were prepared of a "stale" sample of anthracite dust 867 and of a freshly ground sample of the same dust. These suspensions were instilled intratracheally into guinea pigs under general anesthesia. Two, five or eight days later, PAMs were collected from the lungs by bronchoalveolar lavage, and the cells were counted. At two and five days after instillation, all lavage suspensions contained 70 to 85% PAMs, of which 5 to 18% contained phagocytized dust particles. On day eight there were again 80-84% PAMs in all suspensions, but in the presence of "fresh'" dust, 48% of PAMs. had phagocytized particles in comparison to 16% in the presence of '"stale'" dust. A similar experiment was performed in short-term cell culture. During 24 hours, >95%. of PAMs phagocytized dust particles, whether or not the dust was "stale" or '"fresh". Our studies are being extended to determine the effect of (1) removing surface oil contaminants by organic extraction and (2) suspending dusts without surfactant.

Jan 1, 1988

By Charles L. Kimbell

The estimated value of world crude mineral production in 1989 was nearly $1,420 billion in terms of current dollars or more than $1,168 billion in terms of constant 1983 dollars. This latter figure was almost 4.7% above the 1988 level but did not attain the historic high of $1,207.1 billion 1983 dollars set in 1980. The accompanying tabulation provides the latest available revised time series for the value of world crude mineral production in terms of both constant 1983 dollars and current dollars. It also provides one of the two statistical bases for the estimation, this being the data on the value of production of a group of key commodities that was compiled for and published in the authoritative French language mineral industry periodical Annales des Mines for years up to 1983.l It should be stressed that the values just discussed and those presented in the tabulation are for crude minerals only and by no means reflect adequately the role of the entire mineral industry in the world economy. These figures represent only the value of mineral materials as they are mined or otherwise extracted from the earth. They do not reflect the value added to these materials through downstream processing within the facilities commonly accepted as mineral industry plants. That is, value added through beneficiation of ores, smelting, refining, and similar processing is not included in these figures. Comprehensive world data on the value added by such processing are not available; however, a conservative estimate of [ ] the total value of processed output from mineral industry plants derived wholly from primary (newly mined) materials would be on the order of about $2,800 billion constant 1983 dollars or $3,400 billion in terms of 1989 dollars.

Jan 1, 1992

By Bernard Lewis, Guenther von Elbe

"Explosive gas mixtures are characterized by their ability to undergo a self-accelerating reaction that may culminate in ignition. In the case of methane and air there are two interdependent causes of this acceleration. First, if a sufficiently fast reaction is induced, heat may be evolved faster than it is lost to the surroundings; consequently, the temperature rises and the reaction rate increases. Second, the reaction rate is determined not only by temperature but by the concentration of reactive intermediate products if the latter increases during the course of the reaction the rate will increase. To understand the role of these active intermediates, it should be realized that molecules of methane and oxygen, per se, show little tendency to react with each other even at high temperatures.(1) If, however, free radicals like OH and CH3, are present in the mixture, the methane and oxygen are attacked in the reactions(2):In these reactions the radicals are regenerated, and thus a chain of reactions is set up by an individual radical or chain carrier which is broken only if the latter is destroyed in some process. Not all collisions of a chain carrier with CH4 or 02 result in reaction, since one requirement for a successful collision is that the colliding particles have a certain minimum energy. The percentage of collisions in which this energy condition is fulfilled increases with temperature, so that for equal chain-breaking probabilities the length of the reaction chain increases with increasing temperature. Thus, there exists an interplay of temperature and concentration of chain carriers that determines the reaction rate. To carry the rate to the stage of self-acceleration, higher temperatures are required for lower than for higher chain-carrier concentrations, other conditions being equal."

Sep 1, 1939

By Launa Mallett, Michael J. Brnich

The first step to emergency preparedness is defining and analyzing hazards. Although all hazards should be addressed, resource limitations usually do not allow this to happen all at once. Risk assessments are used to establish priorities so that the most dangerous situations are addressed first and those least likely to occur and least likely to cause major problems can be considered later. While the examples provided in this training package are specific to mine fires, the concepts and tools can be applied to any mine hazard. Purpose: This training package was developed to assist instructors, as they: 1) determine how to use risk assessment to improve preparedness for mine fire emergencies and 2) present risk assessment concepts and tools to trainees. Audience: This package is appropriate for workers/trainees from all types of mines. A risk analysis can be conducted by anyone familiar with the location(s) being studied. Why Conduct a Fire Risk Assessment? During a risk assessment, hazards are evaluated in terms of the likelihood that a problem may occur and the damage it might cause. Mine fire preparedness requires consideration of all possible fires that could occur. However, at a given mine some fires are more likely than others and some would result in greater damage than would others. Conducting a risk analysis identifies these differences. The results can be used to target resources at the types of fires that are most likely and/or are most destructive. Hazards that are very likely to result in fires that would do considerable damage to people and property should be targeted first for remediation and/or effective response if remediation isn't possible. Potential fires that are less likely or that would have less severe consequences are identified for attention later, after the more serious situations have been addressed.

Jan 10, 1992

By J. W. Paul

"The economic features of coal mining must take into account the drain on the man power. Study over a recent 5-year period reveals an average yearly loss of 2,125 underground men, of whom 1,182 are killed by falls of roof and coal, and according to recent data compiled by the Bureau of Mines it is estimated that 54,000 men sustain lost—time disabling injuries from the same cause.Under normal activity of the mines approximately 50 lives are taken by falls of roof during every 10 days the mines are operated, or 5 persons are killed per day, which, at a compensation charge of $5,000 each, amounts to $25,000 per day. Add to this the similar number killed by causes other than by falls of roof and we have $50,000 as an approximate daily fatality charge for each day the mines operate. On the basis of 200 working days per year, this amounts to the alarming figure of $10,000,000 annually. An investment at 5 per cent to yield this amount would require $200,000,000, which is equivalent to a capital investment of $0.40 per ton of coal, produced annually, on the basis of 500 million tons. These figures apply only to fatalities for which a fixed or stated amount is paid for compensation and do not include the compensation and hospitalization paid for the approximately 103,000 upon whom idleness is enforced by a lost-time disability injury. In one State having an annual production equal to approximately 30 per cent of the total bituminous production of the United States, the most recent data shows that for each fatality there are eight serious injuries causing 60 days or more lost time. The frequency rate of accidents for that State is less than the average for the United States, and so a conservative comparison may be made by using the figures of that State in estimating the total serious injuries, which gives 16,000 as losing 60 days or more. The average number of underground employees in the coal mines of the United States for the past 10 years has been approximately 570,000; the annual underground fatalities amount to approximately 2,000 and non-fatalities to 108,000, or a total of 110,000, which means that one out of every 5.17 employees ,or 19.3 per cent, receives an injury which results in either a fatality or a lost-time disability; this figure in a little over five years will reach a number equivalent to 100 per cent of all underground workmen. Against this is the record of many miners who have worked 25 years or more without a lost—time disability injury, indicating that coal mining is not necessarily productive of injury or death to workers.In the matter of falls of roof, it is found that 85 to 87 per cent of all fatalities occur at the working face, face of a room or entry, or in pillar work. It is at the working face that the greatest roof hazards are encountered, and when about 75 per cent of the underground employees spend approximately 90 per cent of their working hours at the face, it is logical that there is where injury is most likely to occur.Although the roof hazards may vary in different beds of coal, experience has proved that roof hazards can be successfully controlled in all coal mines, essentially regardless of the character of the roof if constant care and attention are given by the management and employees in applying the principle of safety. In almost every mining district some companies maintain an extremely low frequency rate of injury, whereas in the same district with essentially the same roof conditions the opposite is true.A study has recently been made of a number of reports upon fatalities in one district of one of the principal coal—producing States and it showed that 50 lives had been lost at 23 mines as the result of falls of roof or sides. These reports were made by the mine officials, safety engineers, and safety committees and an attempt was made to give both the cause and the person or factor responsible for the fatality. A summary of the items of responsibility is as follows:"

Feb 1, 1932

By Martin Berman

The Bureau of Mines has investigated the mineral matter content of 38 American coals using X-ray fluorescence. Measurements of the Ka intensity for magnesium, aluminum, silicon, sulfur, calcium, and iron permit the determination of those elements as well as an indirect determination of the ash con-tent of the coals. The percentage of each of the six elements was corrected for absorption by all six elements as well as by hydrogen, carbon, nitrogen, and oxygen. It made little difference whether the values used for hydrogen, carbon, and nitrogen were obtained from chemical analysis or whether average values for all coals were used. In all cases, oxygen was obtained by difference. The correction for absorption by all these elements involved the inversion of a 6 X 6 matrix and was performed by computer. Assuming that the elements magnesium, aluminum, silicon, calcium, and iron were present in the ash as oxides, the quantity of ash was determined. The results for the mineral elements as well as for ash and oxygen were in good agreement with chemical results. Particle size was found to have a significant effect on fluorescence intensities. A study of size effects was made for pyrite particles, since the sulfur content of coals is of particular interest. Theoretical equations were derived and verified relating the intensity to particle size. It was found that the coal samples must be ground to less than 2 microns. Sulfur appears in several forms in coal, and the effect of sulfur form on intensity was investigated. It was found that the Ka intensity was independent of sulfur form but the Kß intensity varied with the type of sulfur. Thus, the Ka intensity was used for determination of the quantity of sulfur present. Utilization of the sulfur KB intensity did not permit a determination of the proportions of sulfur forms present in coal. However, for synthetic mixtures of cystine and pyrite in carbon black, measurement of sulfur Ka and Kß permit determination of each constituents from measurements of sulfur intensities alone.

Jan 1, 1968

By Francis Crowley

Elementary concepts of seismic wave properties are reviewed to establish a framework for discussing seismic noise and its suppression. A liberal number of references is included for those who wish to pursue the topic in detail. A base motion noise level is established for a single surface seismometer. It is argued that simple array processing and seismometer burial should regularly permit us to approach this base noise level which is found in areas free of conspicuous man-made seismic noise sources. The sensitivity of the base seismic level to a number of common disturbances is presented. Solutions that promise to hold the "effective" seismic noise at a site near the base level are given for acoustic, meteorological and fixed local surface sources. Guidelines are suggested for controlling other local man-made sources, e.g. vehicular traffic, by keeping them at sufficiently large distances away from the seismometers to keep noise at permissible levels. These guidelines are speculative and conservative. They should be the subject of future study. The ability to process against general local activity, drilling, and intra- mine sources is limited. Certainly no dramatic gain is to be expected. When strong man-made and/or intramine noise sources are not controllable, detection may well be impossible to achieve, unless the seismometer can be moved close enough to the suspected miner position, i.e. via very deep holes, to compensate for the likely vast differences in strength of the miner signal and the uncontrollable man-made noise sources. However, many intramine sources, e.g., falling water, rock bursts, explosions, etc., may well preclude the existence of a hale miner in their vicinity, and therefore any need to attempt detection of a miner at such locations. The following recommendations are made to enhance the detection and location of a miner signaling seismically. They are: 1. Seismometer burial in slim holes. 2. Narrow band detection, using multiple narrow band filters to cover the likely signal band. 3. Broadband recording and analysis for time-of-arrival estimation.

Jan 1, 1974

By Marie Farnsworth

"The Anhydrite ProblemThe Nonmetallic Minerals Experiment station of the Bureau of Mines at Rutgers University, New Brunswick, N. J. has recently undertaken a study of the chemical and physical properties of anhydrite having in view its wider utilization anhydrite (CaSO4) in contact with water at ordinary temperature and pressure rehydrates, slowly forming gypsum (CaSO4.2H42O). In nature this is an extremely slow process, and laboratory experiments are being conducted to determine methods of accelerating the rehydration. The tests recorded herein cover one this study, and while they are negative in character in so far as the major problem is concerned, certain facts established by the tests, bearing on the stability relations of gypsum and anhydrite seem sufficiently important to be placed on record.Early Researches on Gypsum and Anhydrite.It is to Lavoisiar that we are the first scientific study of the calculation and hardening of plaster of Paris. He sums up his experiments in the following passage: ""If gypsum, which has been deprived of its water of by means of heat, is again treated with water (to make what is commonly called mortar) it takes it up with avidity, rapid and irregular crystallization occurs, and the small crystals which are formed are so entangled in each other that a very hard mass results."" Later, he observed that the dehydration of gypsum occurs in two stages: three-fourths of the combined water is much more easily driven out than the last fourth. LeChatalier first determined the temperature decomposition accurately, his method was as follows: Pulverized gypsum was placed in a glass tube in the middle of a paraffin bath, the temperature of which was raised in a progressive and regular manner. A thermometer gave at each instant the temperature the salt, and the passage of the mercury column past each division of —co. was cared by a registering chronograph. The rise in temperature was except at 128°C. and 168°C. where breaks occurred."

Nov 1, 1924

By Oliver Bowles

"A Product from Mica Mines.Mica commonly occurs in pegmatites which consist of large crystals of feldspar and quartz, mica constituting but a small proportion of the total rockMuch of the feldspar thus thro n out during the process of mining is pure and of high quality, end the Bureau of Mines has suggested that much of it could be utilized for ceramic purposes. Encouragement is given to such utilization by the fact that several mines now worked for mica were formerly operated for the production of feldspar. ""'here mines are not readily accessible to railroads feldspar utilization might not be feasible, for it is a much lower priced product than mica and cannot therefore bear as heavy transportation expense. '""here mines ire located close to railroads, however, such utilization would tend to reduce the cost of mica mining, and at the same time assist in the solution of the waste disposal problem.The Bureau has recently been informed that some of the feldspar from mica mines near Spruce Pine, N.C., is now being sold and shipped away. An extension of this by-product industry is to be recommended.A Mica Deposit in New York City.The Bureau recently received a mica specimen obtained from a. building excavation at 157th St. and Riverside Drive, New York City. The specimen was about 2 by 4 inches in size, and fairly clear though containing numerous hair cracks. It was obtained only 7 or 8 feet below street level. At greater depth and with more careful methods of excavation material of much better quality might be obtained. The material submitted could be used for mica washers but not for sheet mica. It is stated by an official of a prominent mica company that many such fragments are obtainable in this locality and the possibility of the occurrence of a good mica vein is thereby suggested."

Jun 1, 1920

Analyze variably saturated flow in mining and other environmentally sensitive settings through the use of personal computer (PC) based software. The Problem There is an increasing need for mining companies to quantify water contaminants and their migration in the unsaturated zone. New and innovative computer models are therefore necessary to more accurately assess the potential impact of mining activities on groundwater resources and the environment. Applications for unsaturated flow modeling include (1) assessment of the impact of surface or underground extraction mining on flow conditions; (2) assessment of various hydrologic designs for resource recovery, such as in heap leaching or in situ leach mining; (3) assessment of the transport of conservative nonrcactive constituents in response to migration from spoil piles, or acid mine drainage; and (4) assessment of any combination of the above to facilitate expeditious permitting for mining operations. Since the mid 1970's there has been a proliferation of mathematical models and procedures for solving unsaturated now problems; however, few of these approaches have been integrated into software for public use. Commercially available unsaturated flow software models typically are limited to a single application and have restricted approaches. For example, computer codes that solve the unsaturated flow problem based on an analytic expression arc restricted to a simple geometric shape, homogeneous and isotropic materials, and provide only information regarding pressure and flow conditions in specified wells. The variably saturated computer codes that take advantage of the finite difference or finite element approach arc often restricted to either steady state or transient solutions; utilize one specific moisture-retention relationship and moisture-dependent permeability function; do not account for hysteresis; and are used with specific hardware such as a mainframe or work station. This restricts their use because they arc hard to interface, and arc often poorly documented, support dependent, and expensive. The mining community needs a flexible, more broadly based, variably saturated fluid flow simulator for the PC-platform to more accurately predict fluid movement in the mining environment.

Jan 1, 1991

Roof falls continue to be the greatest single safety hazard faced by underground coal miners. During 1996-99, 44 coal miners lost their lives in rock falls, and nearly 2,400 were injured. In addition, nearly 6,000 noninjury roof collapses were reported. Roof supports are installed to protect the miners, but support system failures contributed to most of these incidents. Reducing the terrible toll taken by ground falls continues to be a major goal of research by the National Institute for Occupational Safety and Health (NIOSH). The purpose of these proceedings is to provide the mining community with a comprehensive survey of coal mine roof supports. Drawing on many years of research undertaken by the NIOSH Pittsburgh and Spokane Research Laboratories, this volume describes what types of support are available, how they work, and when they should be used. The major subjects covered include roof bolts, standing roof supports, cable supports, and longwall shields. Some special topics are also addressed, including an analysis of roof fall accident statistics, techniques for better skin control, material handling considerations, and longwall mining through recovery rooms. This proceedings volume also contains information on several important new technologies, which are described here for the first time: •Guidelines for selecting roof bolt length, pattern, and capacity that were derived from statistical analysis of the roof fall experience at 37 underground mines; •A new design method for longwall tailgate supports; and •A technique for measuring loads developed within cable bolts. The papers in these proceedings were presented at open industry briefings conducted by NIOSH on New Technology for Coal Mine Roof Support. The briefings were held in Norton, VA, Charleston, WV, Evansville, IN, Tuscaloosa, AL, Price, UT, Glenwood Springs, CO, and Washington, PA. The papers were also presented at the Mine Safety and Health Administration (MSHA) Preventative Roof-Rib Outreach Program (PROP) Seminar, which was held at the National Mine Health and Safety Academy near Beckley, WV.

Jan 10, 2000

Roof bolting is a slow, expensive, and absolutely necessary mining activity. Roof-bolting activities also account for the largest percentage of lost-time injuries in underground coal mines. Dull bits result in the application of excessive force, which bends drill steel; and changing starter and finisher steel was the most significant source of injuries associated with roof bolting. The tungsten carbide (WC) roof-bolt drill bits currently used in American, Canadian, and Australian coal mines are capable of drilling only one or two 4-ft holes and then they are resharpened once or twice to drill another one or two holes. Often, in medium-hard rock formations (sandstone), as many as 20 to 30 bits may be required to drill a single 4-ft hole. Objective To compare the performance, longevity, and cost of newly developed polycrystalline diamond compact (PDC) roof-bolt drill bits against WC bits. Research and Background Diamonds for industrial use have been scarce throughout history and continuous attempts have been made to produce synthetic diamonds. The first synthetic diamonds were manufactured in 1953. Economically produced synthetic diamonds are 1 to 10 µm in size, but in this size range, they are totally unsuitable for industrial applications. In 1972, General Electric Co. developed a process to sinter the artificially developed, minuscule diamond particles into usable products. In this process, several layers of diamond-particles-and cobalt mixture are overlaid on WC substrates and sintered at 2,350° F and 1,000,000 psi. The final product is known as PDC. Today, PDC's are available in many shapes, but their size is limited to 3/4 in, or less, in length or diameter, because pressures greater than 1,000,000 psi are required to manufacture larger PDC's. At present, diamond and PDC arc the hardest and strongest commercial materials available for wear surfaces. The PDC used in this study had a hardness 3.61 times greater than that of WC.

Jan 1, 1992

Three -dimensional boundary value problems are difficult to solve. Indeed, while the separation of the scalar wave equation can be effected in 11 different coordinate systems, an analytic solution requires that the boundaries, both external and internal, possess the same symmetry as the coordinate system. Numerical methods are thus of great importance for the solution of such problems; however, despite the availability of high-speed, large memory digital computers , the solution to a significant three -dimensional problem is by no means trivial. It is unfortunate that the results reported here by Jones are invalid. Jones discusses a model in which a three-dimensional island lies off a linear coastline where all the interfaces lie in the coordinate planes in a Cartesian system. A downward plane em wave polarized with the electric field parallel to the linear coastline, and two of the islands coast, is incident downward. This, of course, requires that the incident electric field is perpendicular to the other faces of the idealized Cartesian island. The significant equation used by Jones for his finite difference calculations is [ ] where n2 = sµ? . is the conductivity, µ=µo is the permeability of the appropriate medium, and w is the angular frequency of a Fourier component of the incident field. We see that the displacement current term is omitted, which is an excellent approximation for the parameters of interest in this model. In the similar equation for the y- component of the diffusion equation, the same considerations which we are about to discuss are equally valid. It can be seen from the equation that the field components are related and thus any errors introduced will be propagated into all three components. The difficulty arises when Ex or E is perpendicular Y to one or other of the surfaces of discontinuity in s. The continuity of current at the air-earth interface (upper surface), e. g., jy, requires

Jan 1, 1973

By Ronald D. Hill, Elmore C. Grim

1.In 1972 over 595 million tons (51+0 million metric tons) of bituminous coal were mined; 49% of this tonnage was obtained by surface mining methods. Authorities have predicted that the tonnage of surface mined coal will increase in the future, especially since oil and gas resources are becoming limited. 2. Demands for clean air have increased mining activities in the low-sulfur coal deposits in the West. Pollution problems arising from these operations will be considerably different than those found in the East. The deposits are located in arid to semi-arid regions. Coal seams are generally aquifers and are a principle source of fresh water. Therefore mining may result in alteration of groundwater distribution patterns by aquifer disruption. In general, pollution problems associated with western mining are not well characterized. 3.Since any disturbance of the surface will alter the environment in the vicinity of the disturbance, pre-mining planning is a prerequisite to any environmentally successful surface mining operation. If properly carried out, the adverse social, economic, and environmental effects of coal surface mining will be minimized. Certain land areas will be unsuitable for surface mining where: a.Reclamation is not physically or economically possible. b.Mining is incompatible with existing land use plans. c.The proposed mining area is of critical environmental concern. Core drilling is the most satisfactory method of obtaining accurate information for pre-mining planning. 4. Unaccountable strip mining in the past has created problems that are still present today. Contour mining methods that involve the indiscriminate dumping of overburden on the downslope is one of the largest single sources of sediment from strip mining. However, land disturbed by strip mining can be reclaimed. Techniques have been and are being developed by which mining and reclamation are integrated into a single operation. Mountain top removal, head-of-hollow fill, and block cutting are examples in contour surface mining. These methods drastically reduce pollution problems associated with contour stripping.

Jan 1, 1974

By V. Castranova, K. VanDyke

"INTRODUCTION A soluble mediator has been described which is released from activated rabbit leukocytes and induces histamine secretion from rabbit platelets (Barbaro and Zvaifler, 1966; Siraganian and Osler, 1971). This factor has been isolated, characterized and named platelet activating factor, PAF (Bcnveniste et. al., 1972). PAF has since been chemically identified as l-0-alkyl-2-acetyl-sn-glyceryl-3-phosphocholine (Benveniste et. al., 1979; Demopoulous et. al., 1979).PAF is a lipid mediator of broad biological activity. It causes smooth muscle contraction, contraction of lung tissue and decreased FEV 1; while enhancing capillary permeability thus causing edema (Pinkard, 1983). In addition, PAF is a chemoattractant and can lead to inflammation.PAF has been reported to stimulate the release of lysosomal enzymes, leukotriene B,, and lipid metabolites from neutrophils (Smith et. al., 1983; Shaw et. al., 1981; Lin et. al., 1982; O'Flaherty et. al., 1984). The objective of the present investigation was to further characterize PAP-induced stimulation of granulocytes and to develop a bioassay, i.e. chemiluminescence, for screening PAF receptor antagonists and inhibitors of PAP-induced activation of granulocytes. The possible use of the chemiluminescence assay to monitor PAF synthesis by human granulocytes is also described.METHODSBlood was drawn from healthy volunteers into a blood storage bag containing CPD anticoagulant. Granulocytes were partially purified by dextran sedimentation and further purified by centrifugal elutriation as described previously (Jones et. al., 1980). Granulocytes obtained by this procedure were approximately 95 percent pure. The number of granulocytes in this preparation was determined using an electronic cell counter (Coulter Model Z1, Coulter Instrument Co., Hialeah, FL). Isolated granulocytes were used to monitor membrane potential, hydrogen peroxide and superoxide release, oxygen consumption, calcium uptake and, in some cases, chemiluminescence. Studies of PAF receptor antagonists were conducted using neutrophils isolated by density centrifugation. Briefly, blood was layered onto Mono-Poly-Resolving Medium (Flow Laboratories, McLean, VA) and centrifuged at 22 °C and 300 g for 30 min. Neutrophils collected from the second band of this gradient were at least 90 percent pure."

Jan 1, 1989

By T. R. Taubert, D. H. Carlson, J. H. Johnson

"ObjectiveDevelop a portable emissions measurement apparatus to sample and measure tailpipe concentrations of diesel particulate matter (DPM), carbon monoxide (CO), carbon dioxide (COJ, nitric oxide (NO), and nitrogen dioxide (NOJ under steady-state engine load and speed conditions during a 1-minute test.BackgroundThe U.S. Bureau of Mines (USBM) has a comprehensive research program to develop ways to reduce exposure of miners to diesel exhaust pollutants. Engine maintenance has been shown to have important effects on such exposure.Accurate measurements of tailpipe emissions are becoming an essential part of a good maintenance program for underground mines that use diesel-powered vehicles. Past studies of particulates in U.S. underground coal mines have shown that DPM alone may be present at concentrations greater than 1 milligram per cubic meter (mg/m3), half the 2-mg/m3 limit for respirable coal mine dust. A poorly tuned (smoking) diesel engine may be the sole cause for respirable dust concentrations exceeding the limit. Although there is currently no standard specifically for DPM in U.S. mines, regulatory steps are underway, and significant reductions of DPM levels in both coal and metal mines will most likely be required.Tailpipe emission measurements can provide diagnostic information to identify engine malfunctions such as clogged air cleaners, faulty injectors, or incorrect injection timing. In some cases, mine vehicle tailpipe DPM concentrations have been reduced up to 50 percent by engine maintenance and adjustments.An accurate measuring instrument would also be useful for determining the effects of exhaust control devices on tailpipe emissions. Little information is currently available about the overall effectiveness of exhaust controls after long-term use. Raw exhaust concentrations with and without the control device can be measured in underground mines, and from these data a control efficiency can be calculated. Knowledge of the effectiveness of exhaust control devices over time is needed to make intelligent decisions on bow to use and maintain these devices, and when to replace them."

Dec 1, 1995

By F. J. Bailey

"In the fall of 1919, the U.S. Bureau of Mines began an inquiry as to the possibility of utilizing airplanes in conjunction with its rescue work, for quickly transporting engineers and oxygen rescue-apparatus to mine disasters.It was realised that this proposed use of airplanes has serious limitations, and if it were feasible, that the Bureau would have to rely on the cooperation of the established aviation fields of the U. S. Air Service for furnishing airplane service. Therefore Van. H. Manning, Director of the Bureau of Mines, under date of October 28, 1919, wrote the Director of Air Service outlining the rescue and first aid organization of the Bureau, the location of headquarters of district engineers, the distribution of safety cars and stations, and other essential details, and asking whether the Air Service could cooperate with the Bureau in the event of serious mine disasters. Major-General Charles T. Menoher, Director of Air Service, responded that the Air Service would be glad to cooperate insofar as possible, and designated those Air Service stations nearest the district engineers' headquarters, which might be best able to assist.The Bureau of Mines has ten mine rescue cars and eight mine safety stations distributed throughout the mining regions of the United States. The cars are each equipped with sets of oxygen mine-rescue breathing-apparatus and first-aid supplies. The car personnel consists of a mining engineer, surgeon, foreman, first-aid miner, clerk and cook. A foreman miner is in charge of each station and at five of the eight stations are mine safety trucks. The work of the cars and stations is two-fold; (1) Assisting in rescue and recovery work at mine disasters, and (2) training miners in mine rescue and first-aid methods, and in investigations looking to prevention of mine accidents. The country is divided into nine safety districts, with nine district engineers in charge."

Apr 1, 1920

By Joseph T. Singewald

The term "titaniferous magnetite" is used to designate those mag- netic ores of iron that carry more than 2 or 3 per cent of titanium. Large and easily workable deposits of these ores occur in different parts of the world, and have attracted attention for many years. Under present furnace practice, however, the smelting of these ores is both difficult and expensive, and for that reason they are not accepted by furnaces, so that the deposits are practically worthless. The problem of finding a feasible method of utilizing these ores has naturally been attractive, and numerous attempts have been made to solve it. Experiments to that end embrace two lines of investigation. The one that has been the more frequently tried is the elimination of the titanium from the ores, so as to make possible their smelting in the usual way. The other is the devising of a method of smelting by which titaniferous ores may be reduced as economically as are non- titaniferous ores. The former method involves a physical process, the latter a chemical process. The measure of success attainable by the first method depends entirely on the relations between the iron and the titanium in the ore. Views in regard to these relations have been divergent. Some investi- gators have believed the titanium to occur as a part of the magnetite molecule, in which case, of course, any process of mechanical separa- tion would be impossible. Others have believed that the titanium occurs as the mineral ilmenite, and that the ores are aggregates of magnetite and ilmenite. In this case a separation of the two minerals is theoretically possible. Magnetite is highly magnetic; ilmenite is nonmagnetic or only feebly magnetic. Crushing and magnetic con- centration should separate them. Numerous experiments in mag- netic separation have been made with various degrees of success, but rarely has more than a very imperfect separation been obtainable. In other words, some of the titanium exists in a separable form and some in an inseparable form, and the ratio between the two forms is

Jan 1, 1913

"In sum, significant benefits to mine worker health have resulted and should continue to result from the synergistic scientific, engineering, and medical research in respirable dust. As always, an important objective is the rapid dissemination of the results of this research to industry. Video tapes and the Technology News series published by the United States Bureau of Mines (USBM) have been a very effective means of technology transfer. Individual no-cost subscriptions to the Technological News series are available from the Bureau of Mines, Branch of Technology Transfer, 2401 E St., N.W. Washington, DC, 20241.Two respirable dust conferences have been jointly sponsored by the Center, USBM, NIOSH, and MSHA. The proceedings from these conferences are titled:1. Coal Mine Dust Conference held in Morgantown, West Virginia on October 8-10, 1984 and2. Respirable Dust in the Mineral Industries: Health Effects, Characterization and Control held in University Park, Pa. on October 14-16, 1986.Copies of the proceedings from the first conference are available from the National Technical Information Service (NTIS):National Technical Information Service5285 Port Royal RoadSpringfield, VA 22161NTIS # PB86-169380Telephone Number: (703)487-4650Copies of the second conference proceedings, ISBN: 0-936712-76-7 (publication #3010), are available from ACGIH by writing toWilliam D. KelleyExecutive Director, A.C.G.I.H.6500 Glenway Avenue, Building D-FCincinnati, Ohio 45211Telephone Number: (513)661-7881During the period 1984-1987 more than sixty-four (64) papers and publications have been produced by the Center researchers. These publications have appeared in scientific journals and have been presented at national and international symposiums and meetings. A list of these papers, organized by topical headings, has been included in this publication.The generic center maintains a reference center that serves as a clearinghouse for technical information for the generic area and supplies reports on generic center accomplishments."

Nov 1, 1988