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By Eugene V. Cilento, R. Clark Lantz, Kevin A. DiGregorio

"A microscope-based spectrophotometer has been developed to measure superoxide release from single pulmonary alveolar macrophages (PAM) or other phagocytes in culture. Results indicate that PAM respond to stimulation by phorbol myristate acetate (PMA). It appears that some PAM do not release 02 upon stimulation by PMA; however, those that do release 0, show differences in: (I) the total amount of 0, released, (2) the rate of release of 02 and (3) the time delay for release of 02. The significance of measuring 02 release from single cells is two-fold. It allows the simultaneous study of 02 release and electrical potential changes across the membrane of PAM and it allows the study of differences in 02 release among cells. Thus, the function of Normal PAM and the dysfunction of PAM exposed to coal dusts can be more closely studied on single cells.Pulmonary alveolar macrophages (PAM), free cells found in the lungs, protect the lungs by removing inhaled foreign debris and bacteria. The macrophages do this by engulfing and then internalizing the foreign matter (phagocytosis). Stimulation of PAM causes the release of super-oxide radical (02) which has been shown to be the primary metabolite involved in the killing of bacteria by phagocytes (3,8,12). The super-oxide radical is highly reactive and is spontaneously or enzymatically converted to other antibacterial oxidants, including hydrogen peroxide (H202), singlette oxygen ( 02), hydroxyl radical toil'), and hypochlorous acid (HOCl) (2, 3,8,11,12).Exposure of PAM to dusts may lead to dysfunction of this cell-type and to a greater risk of lung damage or infection upon subsequent exposure to toxic dusts. To date, much of the research with this cell-type has used cytotoxicity (cell death) as a measure of dysfunction. Although this is an important end point, PAM dysfunction may occur at doses below those which lead to cell death. In addition, dysfunction has been measured using large numbers of cells. In order to obtain a clear understanding of the mechanisms involved in dysfunction, measurements should be made on single cells. As mentioned earlier, one of the major roles of this cell type is its anti-bacterial actions. Therefore, asessment of release of superoxide radical in single cells is important in determining the functional behavior of PAM before and after exposure to dusts. Since measurements of 02 production have not been made on single cells the purpose of this study is to develop the methodology needed to study release of 02 from single cells.Recent studies have suggested that a relationship exists between the release of 02 and changes in the electrical properties of phagocytes. The change in membrane potential is thought to be the initial step in superoxide production (6,9). Stimulants which cause 02 release also cause changes in the transmembrane potential of phagocytes (9) and in the permeability of the cell membrane to ions (6). For example, stimulants which cause the release of 0, from neutrophils have also been shown to increase the membrane transport of Na+ , K+ and Ca+2 and stimulation of macrophages leads to increases in Na and perhaps Ca permeability with a subsequent change in membrane potential. In some cases, phagocytic activity has been shown to depend upon the extracellular concentrations of these ions (6). Holian and Daniele (7) have shown evidence that the redistribution ofcellular Ca in alveolar macrophages is an initial step leading to 0, release. In order to provide direct evidence that 02- production is related to electrical changes across the plasma membrane of phagocytes, these two phenomena must be analyzed simultaneously on single cells. Ultimately, measurements of 0, release using the methodology developed in this study will be combined with electrophysiological tech¬niques to study both superoxide release and membrane potential changes simultaneiously on single PAM, and to examine the effects of coal and mineral dusts on their physiological fu"

Jan 1, 1988

By Steven J. Page, William A. Heitbrink, Andrew B. Cecala, Edward D. Thimons, John A. Organiscak

Miners at noncoal surface mining operations are often exposed to high levels of respirable dust. In an effort to lower the respirable dust exposure of these surface miners, the National Institute for Occupational Safety and Health (NIOSH) has been conducting research to address this problem in a practical and economically viable manner. One successful effort deals with lowering the dust exposure of equipment operators in enclosed cabs. Many types of surface mining equipment utilize enclosed cabs to protect equipment operators from dust exposure. Normally when the equipment is new, the cabs are fairly airtight. These tightly sealed cabs, combined with good filtration systems, generally provide the operator with good dust protection. However, most mining equipment is older, and as aging occurs, many components of the enclosure deteriorate. The structural integrity of the cab diminishes and the effectiveness of the air filtration system fails. NIOSH has been successfully researching costs-effective methods to improve both filtration effectiveness and cab integrity of these older cabs in order to provide a healthier work environment for equipment operators. Dust sampling records indicate that drill operators and helpers have the highest dust exposure of all workers at surface mining operations. Since much of the overburden contains a high percentage of silica, the health hazard associated with this dust can be even more serious. NIOSH research is addressing techniques to lower respirable dust levels at surface drilling operations. INTRODUCTION NIOSH's mission is to assure a safe and healthy work environment for the working men and women of this nation. The primary emphasis of NIOSH's Pittsburgh Research Laboratory (PRL) is mining health and safety research. This report focuses on two areas of research

By G. E. McElroy, D. Harrington

The use of shall electrically- driven fans , in conjunction with air- pipe of various diameters is becoming of increasing importance for the ventilation of working places in metal mines through which the general ventilating currents can not be coursed . It will probably continue to increase in importance since the concept that air motion is the most important factor in maintaining comfort in hot ( above 80° F . ) working places is more generally accepted , and as the inefficiency and greater expense of attempting to ventilate such places with compressed air is recognized . Managers of large properties can afford to experiment with fan- pipe installations until types are found that meet their conditions , but managers of shall properties , unless forced to it by extreme conditions , prefer to wait until they can obtain data sufficient to guarantee at least a measure of success from such installations . At present , such data , even in part , are available to only a few (mainly fan manufacturer's representatives , consulting ventilation engineers , and ventilatin engineers employed by large companies ) , and important recent developments are mostly of a confidential nature . One large metal - mining company cooperated with a fan manufacturer in some extensive experimental work on small blowers and found that instead of using stock fans , considerable power economy could be effected and equal quantities of air delivered by use of or 2/3 width fans with small motors rather than using stock fans and larger motors ; it was also found advisable to adopt certain sizes of tubing for certain lengths of run . In fact , many important facts were ascertained in this study , and it is now promised that they will soon be given to the public . It is true that a certain amount of data on industrial installations are available , but such data are only in part applicable to metal -mine conditions , because , until recently , little attention has been given to ventilation in metalmines , and the conditions encountered usually require a greater length of pipe , a more temporary type of construction , and closer attention to temperature control than the ordinary run of industrial installations demands ..

Feb 1, 1922

By S. D. Sanders

Goals of the Bureau of Mines include utilizing readily available minerals as substitutes for scarce mineral commodities and minimizing occupational hazards associated with mineral processing occupations. Therefore, the Tuscaloosa Research Center investigated using rapid-set cement as a suitable molding sand binder for small ferrous castings; currently petroleum-based binders are used. Substitution of a rapid-set cement would eliminate organic vapors associated with the petroleum-based binders; these vapors constitute occupational hazards and environmental pollutants. A binder containing 60 percent white portland cement (WPC) and 40 percent calcium aluminate (CA) would be an acceptable and economic substitute for petroleum-based binders where the foundry requirements are compatible with its limitations. It produced a set time and a pattern strip time of less than 1 hour. Cement, sand, and water mixtures developed compressive strengths from about 40 to 75 psi after 2 hours and from 120 to 130 psi after 24 hours. Tensile strengths of 18 to 22 psi were obtained after 2 hours, increasing to 30 to 35 psi after 24 hours. The addition of about 1 percent polyphosphate to the sand-cement-water mixture doubled the compressive strength and increased the tensile strength about 50 percent after 4 hours, but also increased the set time from 30 minutes to 1 to 1-1/2 hours. Po1yvinylacetate (PVA) resin latex additions resulted in rapid strength development. When castings were poured into the cement-bonded molds, the surface finish was fair to good on gray iron castings, but some areas of burn-on were present on steel castings. Using a graphite wash on the cement-bonded molds produced good surfaces on gray iron castings.

Jan 1, 1979

By Oleg Terichow

The Bureau of Mines studied the penetration of a slender cylindrical tube into a sand bed, simulating seafloor material under the application of a static load. The factorial experimental design was based on three factors: tube diameter, geometry of penetrating bit, and seawater saturation of sand, all of which were found to be significant in influencing the depth of penetration. The geometry of the penetrating bit, or shoe, is of major significance in the mechanics of penetration and should be considered the most important factor for additional study. Linear regression analyses of the load-penetration data show that the relationship is linear.

Jan 1, 1970

By R. V. Higgins

This report presents the results of a study of gas injection in the Upper and Lower Terminal zones in fault block VB and in the Upper Terminal zone in fault block VI, Wilmington field, California. This report is based on data obtained to January 1956. Earlier studies of gas injection in other California fields have been reported .3/ The Upper and Lower Terminal zones, fault block VB, have been producing oil since 1945 and the Upper Terminal zone, fault block VI, since 1948. Before starting the gas-injection project, the expansion of dissolved gas was the principal mechanism moving the oil to the wells. Gravity drainage and an edgewater drive also have contributed to the movement of the oil to the wells. When the gas injection was begun, the reservoir pressure and the oil production had declined appreciably. Gas injection was started in the Upper and Lower Terminal zones, fault block VB, in May 1953 and in the Upper Terminal zone, fault block VI, in October 1953.

Jan 1, 1957

By J. D. Davis

From the chemist's point of view it would be ideal if specifications for coke for any stated purpose could be written on the basis of chemical composition and burning characteristics. Unfortunately this is not possible. In fact, the physical properties of a coke are often of such major importance as to render any specified chemical requirements totally inadequate to show the quality of coke desired. For example, a furnace coke may admirably fill all chemical requirements, such as for low phosphorus, sulphur, moisture, and high fixed carbon, and still be too soft to support the burden of the furnace without excessive crushing. Again, a domestic coke though a good fuel as judged from Chemical analysis, may be of unmarketable size. Thus one can not define the quality of a coke for a specified purpose without taking into account both its chemical and physical characteristics even when this has been done the specification may fail because neither coke user nor producer can accurately define by quantitative tests the qualities most desired. In other words, there is need of accurate test methods for measuring the properties of coke and, what is equally important, for correlating the results with the behavior of the coke in use. Coke quality is determined by the kind of coal used, the coking process, and the type of equipment used in the coking process. Chemical analysis of the coals, together with small-scale coking tests, will give a good indication of their suitability; but, in general, coke must be produced on an industrial scale and tested in the equipment for which it is intended before conclusive information as to its quality is obtained.

Jan 1, 1928

By Irving Hartman

The results of the first experimental study by the Bureau of Mines on the explosive properties of metal powders were published in 1945. Since that time the explosibility of numerous other industrial dusts and powders has been investigated. Part of this information has been published, but most of the data has not been released to date. This paper summarizes the results of experiments on 22 samples of titanium, zirconium, thorium, uranium, and hydrides of these metals. The major part of the investigation was made under cooperative agreement with the Atomic Energy Commission.

Jan 1, 1951

By R. L. Grant, R. W. Van Dolah, N. E. Hanna

An experimental investigation was conducted to assay the relation between natural gas concentration and ignitibility of the gallery atmosphere . Both the gas concentration representing maximum ignitibility and the relationship between certain properties of the explosives and their incendivity are discussed . The data show that variation in the natural gas content in the gallery can have a highly significant effect on ignitibility of the gallery atmosphere ; maximum ignitibility of the atmosphere by permissible explosives occurs with approximately 8.1 percent natural gas . The study also shows that incendivity of a permissible explosive cannot be determined only by its detonation velocity , oxygen balance , or ballistic mortar strength . However , for similar type explosives , trends observed indicate that their incendivity increases with detonation velocity or bulk strength . Additionally , for underoxidized explosives studied here , the more negative the oxygen balance the less incendive was the explosive within a class defined by salt content .

Jan 1, 1963

By Doris M. Hyde

Limited geographically by size and geo-logically by origin, smaller countries and territories of the Caribbean are nonetheless engaging in efforts to encourage the initiation of mineral and mineral-related industries. Petroleum dominates the minerals sector, which otherwise consists principally of minor quantities of construction-oriented materials, usually for local consumption. The increased cost of petroleum has adversely affected most of the world, but these islands with their economies precariously balanced on the uncertainties of agriculture and tourism are especially vulnerable to petroleum's direct and indirect costs. In 1975, the Government of Antigua acquired the financially troubled West Indies Oil Company refinery at St. Johns. The refinery ceased operations in 1976. In 1979, negotiations were underway to sell Ashland Oil Co. an interest in the small, 20,000-barrel-per-day refinery for $6.6 million. In 1977, Antigua granted petroleum exploration rights to the Antigua Mineral Exploration Company, which planned to drill in an undefined offshore area, possibly between Antigua and Barbuda. The company expected to spend about $200,000 per year through 1982. There have been no reports on its activity.

Jan 1, 1981

By R. Hogg, T. F. Dumm

"It is generally agreed that dust characteristics play a role in the development of Coal Workers' Pneumoconiosis (CWP). Unfortunately, there is a serious lack of information on what the characteristics of mine dust actually are and how they vary among different mining regions, coal seams, etc. This paucity of data can generally be attributed to the serious problems encountered in collecting sufficiently large quantities of dust for conventional analytical procedures.Personal samplers are widely used in coal mines for regulatory and enforcement purposes. Generally, these provide information only on the total (respirable) dust loading in the mine atmosphere and on the mineral matter (primarily quartz) content of the respirable dust. A procedure has been developed by which samples collected with a slightly modified personal sampler can be analyzed for particle size distribution, total mineral matter content and elemental composition, in addition to the standard mass and quartz measurements. These analyses could readily be performed on a routine basis. Shape analysis by Scanning Electron Microscope (SEM) could easily be included if appropriate shape criteria are established. Extension of the procedure to include the determination of complete size/specific gravity (composition) distributions is quite straightforward provided sufficiently large samples (at least 10 mg) can be collected. Typical sample sizes for a personal sampler carried by a miner for one shift range from about 0.5 to 2 mg.The basic procedure was developed and evaluated using synthetic mine dust prepared in the laboratory. Field tests in three working mines in Pennsylvania and West Virginia have confirmed the applicability of the approach to the real world. Particle size distribution measurements on mine dust collected in the modified personal sampler were found to agree closely with the results of simultaneous in situ measurements obtained using cascade impactors."

Mar 1, 1989

By H. W. Wainwright

One phase of the research and development work on synthetic liquid fuels conducted by the Bureau of Mines at Morgantown, W. Va. in cooperation with West Virginia University deals with the purification of synthesis gas.2/ Most of the experimental studies on gas purification have been directed toward the removal of organic sulfur from gas, either catalytically or by adsorption with activated carbon. An important part of the purification program has been the development of suitable analytical methods for determining organic sulfur compounds. As the total sulfur content, organic and inorganic, of purified synthesis gas should not exceed 0.1 grain per 100 cubic feet, the need for accurate analytical methods is apparent. It is also apparent that such methods must be rapid if one wishes to evaluate various processes for removing sulfur from gas. The organic sulfur found in most gas produced from coal is usually present as carbon disulfide, carbon oxysulfide, methyl and ethyl mercaptans, and thiophene, with the exception of thiophene, the remaining organic sulfur compounds respond similarly to catalytic treatment and can be removed effectively. Not only does thiophene resist most catalytic treatment, but it poisons some catalysts, rendering them ineffective in removing the other forms of organic sulfur.

Jan 1, 1950

By Laxman S. Sundae

The Bureau of Mines designed, fabricated, and is using an in-seam tester (1ST) for in situ determination of coal cutting forces. This re-port describes the results of field tests conducted in the Pocahontas No. 3 and Upper Freeport seams to obtain peak and mean cutting forces during coal cutting with several bit geometries, including radial and point attack bits currently used on drum-type machines. Comparisons were also made between new and worn bits, and using data obtained from a Bureau-modified chisel bit. The test results show that longwall plough cutting (horizontal cuts) in bony coal bands (shale) requires >3 times the cutting force for the same cuts in a vertical direction. When no bony coal is present, the cutting forces required to make horizontal and vertical cuts are equal. Worn bits require 4 to 5 times more cutting and normal force than new or undamaged bits. Normal force increased drastically for the worn chisel bit. Peak force encountered in making independent cuts was found to be ~3 times higher than that required to make interactive cuts using a spacing-to-depth-of-cut ratio of 2. Both rake and clearance angles were found to have a significant effect on normal and cutting force.

Jan 1, 1986

By David W. Wisecarver

This report describes a tool to engage and/or place a Bureau of Mines type gage to measure borehole deformation in a horizontal , 1½ - inch - diameter , stress relief borehole . The tool was successfully used at a borehole depth of 105 feet . Practical usage up to borehole depths of 200 feet might be realized . The tool was designed to work inside EX- size ( 1½ - inch ID ) diamond - drill drive casing used as drill rod and through which the deformation gage is guided into an EX- size stress relief borehole . Through laboratory experiments it was found that by exercising a reasonable amount of care the deformation gage could be placed at a point within a ± .01 foot distance of a predetermined depth in a horizontal EX- size hole and that the deformation measuring piston or plunger of the gage could be oriented in the borehole within 0.5 ° of a preselected angle of orientation in a vertical plane .

Jan 1, 1964

By John C. Edwards

The Bureau of Mines has developed a time-dependent mathematical model of radiative heating of bulkheads in mines. The model includes both reradiation from the duct (cylindrical) walls and direct radiation from the fire zone. Thermal loss into the wall of the duct and into the bulkhead is included. Both brick and wood bulkheads are considered. It is found that the heating rate of the system scales as the duct length-to-diameter ratio and the flame temperature. In particular, the time required for the irradiated surface of the bulkhead to reach a specified temperature decreases with increasing flame temperature for a fixed length-to-diameter ratio and increases with increasing length-to-diameter ratio for a specified flame temperature. It is also deter-mined that the time, T, for the bulkhead surface temperature to reach a specific value, Tb, for a fixed length-to-diameter ratio less than 4 and for a flame temperature of 1,200 K is approximately linearly dependent on Tb for 500 K < Tb < 700 K, and is nearly exponentially dependent on the length-to-diameter ratio for Tb = 600 and 700 K.

Jan 1, 1979

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Guatemala has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State.

Oct 1, 1929

By LB. Berger

"INTRODUCTION The use of gasoline engines as the motive power for lift trucks, tractors, and other types of mobile equipment operated in enclosed spaces, such as industrial plants and warehouses, may create a hazard because of the carbon monoxide present in the exhaust gases of the engines; gasoline-powered equipment should not be used in mines or tunnels. Because the equipment is mobile, local ventilation usually is impracticable, and general ventilation of the spaces is nec-essary to dilute and remove the carbon monoxide. To estimate the rate of ventilation required in such situations, information is necessary on the concentration of carbon monoxide in the exhaust gas and the rate at which exhaust gas is produced under given operating conditions. The purpose of this paper is to present data that may be used in making estimates of ventilation requirements.COMPOSITION OF GASOLINE-ENGINE EXHAUST GASThe exhaust gas of a gasoline engine consists mainly of carbon dioxide, carbon monoxide, hydrogen, oxygen, and unburned hydrocarbons (usually reported as methane), together with the nitrogen present as a residue from the air sup-plied for combustion. 3/ The exhaust also contains water vapor resulting from combustion of the hydrogen of the fuel. The water-vapor content is not included in exhaust-gas analyses calculated on a ""dry"" basis and is not involved in the estimation of ventilation requirements."

Jun 1, 1947

By Carlon S. Land

The Bureau of Mines investigated the influence of a free gas saturation on oil recovery by water drive. A digital computer was used to calculate the combined oil recovery from solution-gas drive to various states of depletion. Results of these calculations are compared and optimum conditions for the maximum oil recovery are found for various fluid-rock systems. For most of the fluid-rock systems, the calculations show an optimum gas saturation other than zero. Using fluid and rock properties as parameters, graphs are plotted showing the optimum gas saturation and increase in oil recovery brought about by the gas saturation. The effects of fluid properties and relative permeability on the optimum gas saturation are seen in these graphs. The graphs can be used as guides in connection with other considerations in determining the optimum time to start a waterflood. They should also be helpful in determining the MER of a water-drive reservoir. The effects of compressibility and solubility of the trapped gas saturation are investigated for select cases using a backward difference scheme to solve the partial differential equation of three-phase flow. From these calculations, it is observed that some benefit of a gas saturation remains for injection pressures up to 1.5 times the original bubble-point pressure.

Jan 1, 1974

By D. E. Wolfson

As a part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report.2/ The inherent suitability of coal for metallurgical use depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, as well as the available reserves, are considered in selecting coals for carbonization tests.

Jan 1, 1957

By W. H. Lewis

This Bureau of Mines report and its companion report (Information Circular 9074) have been prepared as a complete reference on underground coal mine lighting. This report discusses the fundamentals of light and its interrelationship with the visual process. The purpose of the report is to insure an understanding of the numerous complex and interrelated factors that must be considered to design and implement a mine lighting system that will satisfy human needs for good vision and comfort. Topics include history, objectives, and technical considerations of coal mine lighting; light physics; light and vision relationships; and disability and discomfort glare.

Jan 1, 1986