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By X. C. Shi

Bacterial mutagenicity and mammalian cell chromosomal and DNA damage in vitro assays were performed on a diesel exhaust particulate material (DPM) standard in two preparations: as an organic solvent extract, and as an aqueous dispersion in a simulated pulmonary surfactant. U.S. National Institute for Standards and Technology DPM SRM 2975 expressed mutagenic activity in the Salmonella reversion assay, and for in vitro genotoxicity to mammalian cells as micronucleus induction and as DNA damage in both preparations: as an acetone extract of the DPM mixed into dimethylsulfoxide, and as a mixture of whole DPM in a dispersion of dipalmitoyl phosphatidyl choline. Dispersion in surfactant was used to model the conditioning of DPM depositing on the deep respiratory airways of the lung. DPM solid residue after acetone extraction was inactive when assayed as a surfactant dispersion in the micronucleus induction assay, as was surfactant dispersion of a respirable particulate carbon black. In general, a given mass of the DPM in surfactant dispersion expressed greater activity than the solvent extract of an equal mass of DPM.

Jan 1, 2009

By M. C. Irani

This Bureau of Mines survey of methane emissions indicates that total daily emissions have declined from 227 MM ft3 in 1971 to 214.7 MM ft3 in 1973. The highest average daily emissions in million cubic feet per day observed in U.S. bituminous coal mines were, in decreasing order, Monongalia County, W. Va., 40.7; Marion County, W. Va., 23.1; Buchanan County, Va., 22.1; Washington County, Pa. , 12.4; Greene County, Pa. , 11.7; McDowell County, W. Va. , 11.4; Cambria County, Pa., 9.8; Jefferson County, Ala., 9.5; Wyoming County, W. Va., 6.0; Marshall County, W. Va., 4.8; and Indiana County, Pa., 4.8.

Jan 1, 1974

By W. C. Holliman

This report on the characteristics of commercial aviation gasolines is one of a series of such reports. It presents compilations of' inspection data furnished on their products by 15 manufacturers of commercial grades of aviation gasoline and special data obtained in Bureau of Mines laboratories on 68 samples of these gasolines. Data are presented for 18 samples of grade 80, 20 of grade 91/98, 21 of grade100/130, and 9 of grade 115/145 aviation fuels. The gasolines are designated January 1948 production, although some of the samples actually were produced at a later date.

Jan 1, 1948

By J. J. Hoeppner

Accurate determination of moisture in coals of various ranks has long been a subject of intensive investigation. Excellent reviews of methods developed over many years are given by Brown (9)4/ and, with experimental comparisons, by Goodman, Gomez, and Parry (11). As pointed out in these and other writings, one of the principal difficulties in assigning absolute merit to one or another procedure is the multiplicity of conditions under which water may exist in coal and the difficulties involved in obtaining sharp separation and distinction between these classes. Gauger (10) states: Water recoverable from coal is obtained from the following sources: (1) Decomposition of organic molecules (sometimes called combined water), (2) surface adsorbed water, (3) capillary condensed water, (4) dissolved water, and (5) water of hydration of inorganic constituents of the coal.

Jan 1, 1956

By C. W. Owings

The Bureau of Mines has conducted a survey to determine potential exposure of mine workers to dust produced in connection with intermittent rock drilling in coal mines. Eighteen mines in 3 states were visited, and 30 different operations were observed, as follows: 10 drilling in draw slate, 8 drilling top rock for brushing or grading, 2 drilling in the coal face, 4 drilling in the bottom, 2 drilling top rock for overcasts, 2 drilling in faults or boulders, 1 drilling for roof bolting, and 1 drilling for trolley hangers. Dust respirators were worn by drilling crews during 16 of the 30 operations. Three hundred thirty-two samples of air-borne dust were collected during the survey. ACKNOWLEDGMENTS The information in this report is based on samples collected and observations made in bituminous-coal mines. Operating officials at these mines have contributed to this study, and their cooperation is gratefully acknowledged. All samples were counted by Thomas B. Kirby, chemist, and Dominick A. Ambrosia, scientific aid, and were analyzed by Gretta S. Baur, physicist, and Patricia M. Gussey, scientific aid, of the Health Branch of the Bureau of Mines.

Jan 1, 1953

By H. P. Greenwald

"INTRODUCTION In the course of its studies of the explosibility of various coal dusts in the Experimental coal mine, the Bureau of Mines has tested coals representing the entire range of volatile content found in the United States. In connection with their work the Bureau's field engineers some¬times meet operating officials who are not impressed by the fact that there is an explosion hazard in mines working low—volatile coals. Actually the difference in explosion hazard between high—volatile and low—volatile coals is one of degree and not of kind. The purpose of this paper is to set forth briefly the experimental evidence that has been accumulated on the explosibility of coal dusts containing 8 to 31 percent volatile matter on a dry, mineral—matter—free basis.There have been numerous dust explosions in mines in which coals were worked that have compositions within this range. Those explosions are listed in an appendix, together with a bibliography of Bureau of Mines papers describing explosion tests in the Experimental coal mine."

Jan 1, 1940

By Richard W. Watson

Card-gap and projectile impact sensitivity data are presented for a wide variety of explosive compositions tested at the Bureau of Mines in more or less standard test geometries. The results of both tests are in good agreement in that they provide the same sensitivity ordering for different subclasses of explosives. Least sensitive were homogeneous liquids that did not exhibit a tendency to undergo low-velocity detonation, ammonium nitrate-fuel oil, and most cast military explosives. Of intermediate sensitivity were pressed and powdered military explosives, cast pentolite, permissible and non- permissible water-based explosives, and one commercial two-component explosive. The most sensitive were permissible and nonpermissible dynamites and explosives susceptible to low-velocity detonation.

Jan 1, 1973

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage arc also described. IntroductionThe association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate ·formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation.In its most general form, the process of agglomeration involves taking discrete, independent particles, bringing them into contact with one another, promoting (or allowing) interparticle adhesion to occur and then causing structure rearrangement, usually under the action of external forces. The relative importance of these steps varies with the nature of the particulate system being agglomerated and with the kinds of agglomerates being produced. Coagulation or flocculation of particles dispersed in fluids is generally dominated by the contact and adhesion steps. In the granulation of powders, on the other hand, particles are already in contact so that structure rearrangement is the principal step."

Mar 1, 1992

By R. E. Kennedy

The presence of combustible gases and vapors in air can constitute n extremely serious explosion hazard. This hazard is even greater when explosive mixtures are confined under high pressures, as the pressure can become tremendous immediately before the container is ruptured. Because of its interest in safety in mining and. allied industries, the U. S. Bureau of Mines has investigated the explosive properties of a number of gaseous and liquid compounds; the results of these investigations have been published in various government papers and journal articles. The increased use of liquefied, petroleum gases has intensified interest in the effect of high pressures on the explosibility of propane-air mixtures. The limits of flammability of natural gas-air mixtures have been determined at pressures ranging from 50 min. Hg to 3,000 p.s.i. As it is known that a combustible. gas or vapor cannot burn or explode when the oxygen content of the atmosphere is less than a certain value, critical values were determined for the oxygen content of atmospheres to which nitrogen had been added as a diluent. In this connection limits of flammability were determined for ethane in atmospheres containing added. nitrogen or carbon dioxide at pressures up to 900 p.s.i.g.

Jan 1, 1951

By E. B. Kester

In the commercial evaluation of coal tars, a distillation analysis properly carried out is of considerable importance. Close attention must be given to this operation in order to obtain consistent results and to secure the minimum decomposition of the tar compounds, Which in Many cases are sensitive to undue heat effects. Low-temperature tars in particular contain compounds of this nature, while in the case of tars produced at high temperatures the large proportion of pitch present has an adverse influence during a distillation. If excessive cracking takes place, the composition of the distillate will naturally vary from the normal, with the result that all the analytical criteria subsequently obtained are affected. Where tars, produced over wide ranges of carbonization temperatures are investigated as in the survey of gas, coke, and by-product making properties of American coals now being conducted at the United States Bureau of Mines Pittsburgh Experiment Station, the method of distillation must necessarily be the same for all of the tars studied. Also, it mast function equally well for both low and high temperature tar permit accurate fractionation, and reduce adventitious decomposition to a minimum. The authors are aware that certain types of distillation analysis which do not meet the above requirements may give results comparable with those of the large stills of a by-product coke-plant where one type of tar is produced. These may be simpler and shorter and entirely suitable for control work, but at the same time have little value in a fundamental investigation.

Jan 1, 1932

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid-particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage are also described.INTRODUCTION The association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation."

Jan 1, 1989

Four catalytic converters for diesel exhaust systems were tested to determine their effectiveness in reducing the amount of harmful substances discharged into the air. Tests were conducted with four different catalytic converter designs, using two diesel engines as exhaust gas generators. (Of the four noble metal catalytic converters, three are commercially available.) Testing showed that the catalysts varied widely in oxidation efficiency at light to intermediate engine loads, but that all were very effective in reducing emissions of CO, HC, aldehydes, and odor intensity at heavy loads (engine operating modes resulting in high exhaust temperatures). Particulate loading, particulate size, and NOx emissions were generally unaffected by any of the catalysts. The catalysts had one ad-verse effect on exhaust quality--increased sulfate emissions. Because of the potential problem of sulfate emissions, the exclusive use of catalytic reactors for emissions reduction does not appear to be satisfactory. However, when used with a means for subsequent removal of sulfates, a catalyst can function as a key component in an emissions control system for diesel engines operated in underground mines.

Jan 1, 1978

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Galis Mfg. Co. roof drill. The instructions are based upon two actual installations: one made in a mine on roof drill, model 300, and one in the factory. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other roof drills with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other roof drills and can determine any necessary modifications if they are not.

Jan 1, 1973

By Eliot J. White

The Bureau of Mines tested cores from 35 wells from 14 oil-producing zones in southern Illinois, southern Indiana, and western Kentucky to determine why rates of water injection were apparently low in some zones. Since these zones contain only minor amounts of clay minerals, it is concluded that permeability reduction results from movement of dislodged silica particles and other material, including the clays, that lines the pores. Both single-phase and two-phase permeability measurements, however, indicated that most samples had only low to moderate water sensitivity, so that permeability reduction due to such particle movement should usually not be of practical significance. The effective permeability to water was considerably lower than the effective permeability to oil during two-phase flow measurements, as is typical of most reservoir rocks. It can be concluded, therefore, that relatively high injection pressures will be required in waterflooding thin zones or zones having low permeabilities.

Jan 1, 1966

By L. A. Haas

Hydrogen sulfide was decomposed to elemental sulfur in an electrical discharge. With He, N., or Ar diluents, a threshold voltage between 1 and 3 kV was required for the decomposition reaction to occur in a laboratory ozonizer. Above the threshold voltage, the HAS decomposition rate increased with increasing voltage, but the increase was more pronounced with argon diluent than with either nitrogen or helium. In common with other reactions in an electrical discharge, the B2S decomposition decreased with increasing temperature in the range of -410 to +61° C. The reaction did not appear to be rate-controlled by a solid-gas sorption step because the introduction of activated charcoal into the electrical discharge zone did not significantly affect the decomposition yield. In the presence of polymeric chlorofluoro-carbon oil, 90 pct conversion of the 3 pct H2S in helium was obtained at 14 kV, 60 Hz, a 2-mm electrode gap, and a gas-residence time greater than 1 min. Under the same experimental conditions in the absence of oil, the conversion was only about 50 pct.

Jan 1, 1973

By E. B. Kester

In the commercial evaluation of coal tars, a distillation analysis properly carried out is of considerable importance. Close attention must be given to this operation in order to obtain consistent results and to secure the minimum decomposition of the tar compounds, which in many cases are sensitive to undue heat effects. Low-temperature tars in particular contain compounds of this nature, while in the case of tars produced at high temperatures the large proportion of pitch present has an adverse influence during a distillation. If excessive cracking takes place, the composition of the distillate will naturally vary from the normal, with the result that all the analytical criteria subsequently obtained are affected. Where tars, produced over vide ranges of carbonization temperatures are investigated as in the survey of gas, coke, and by-product making properties of American coals nor being conducted at the United States Bureau of Mines Pittsburgh Experiment Station, the method of distillation must necessarily be the sane for all of the tars studied. Also, it must function equally well for both low and high temperature tar, permit accurate fractionation, and reduce adventitious decomposition to a minimum.

Jan 1, 1932

By M. R. Geer, H. F. Yancey

Fuel requirements of the Pacific Northwest have been increased greatly by the war . To the normal peacetime demands for fuel have been added the requirements of new industrial and metallurgical plants engaged in war production , the increased demand arising from expansion of existing industrial establishments , increased amounts of railroad fuel required to handle wartime traffic , and increased quantities of domestic fuel required by the influx of war workers . In the face of these augmented demands for fuel shipments of fuel oil have been curtailed , wood fuel which normally is an important factor in both industrial and domestic markets of the area is less abundant , and the production of coal in Washington has decreased sharply . The fuel requirements of the region have been met so far by shipping large tonnages of coal into the Pacific Northwest from Utah , Wyoming , Montana , and Colorado ; the quantity received from these States and Canada in 1943 amounted to 2,688,9124/ tons , 175 percent of the Washington production . or The proximity of the Washington coal mines to large centers of war production has resulted in widespread migration of miners to employment in shipyards and aircraft plants ; the ensuing shortage of miners largely accounts for the decreased production of coal in the State . Hence , strip mining , which requires relatively few workers and a shorter time for development , offers an attractive means of alleviating the local coal shortage and obviating the necessity of shipping coal from the producing areas of the Rocky Mountain States to the Pacific.coast . So urgent has been the necessity for augmenting local coal production that any coal property that promises to be amenable to strip mining , even though the coal may be inferior in quality , has warranted examination . Even low- grade coals that cannot compete in the normal market can be used locally , thus releasing better coals for shipment to critical centers. of consumption ... One such deposit of low- rank fuel examined by the Bureau of Mines is in western Lewis County , about 9 miles east of Toledo , Wash . The coal is lignitic and on the as - received basis has a heating value of 6,000 to 6,500 B.t.u. per pound . The property is of interest primarily because the physical conditions favor operation by stripping and offer opportunities for low- cost production with very low manpower requirement .

Jan 1, 1945

By E. D. Gordner

U. S. Bureau of Mines

Jan 1, 1923

By J. M. Mutmansky, L. Xu

"IntroductionSince the establishment of the star,just concentration of 2 mg/m3, a strong effort has made by mining engineers and researchers to provide better dust control equipment and procedures for underground coal mines.Particular areas of success have been implementation of better coal-cutting strategy to control dust generation, better design of water sprays for dust suppression and air movement, use of scrubbers, and improved design of face ventilation systems. A drastic improvement occurred over time such that the average dust concentrations for continuous miner operators dropped from 6.5 mg/m3 in 1968 to 1.3 mg/m3 in 1980 and for auger, cutter, longwall, and roof bolter occupations from 2.7 mg/m3 in 1973 to 1.6 mg/m3 in 1980 (Niewiadomski, 1983).While dust concentrations in mining sections have been dropping considerably, one problem area has been mining sections where quartz is a considerable portion of the airborne dust. The federal regulations require that quartz content must be held below 0.1 mg/m3 in the air regardless of the concentration of the total dust. This legislation limits the allowable dust concentration to a ""reduced standard"" of 10/ (% quartz) when the quartz content of respirable dust in the mine atmosphere is more than 5%. Today, approximately one-third of underground coal mining operations have designated areas with more stringent dust standards in place, and many mines experience considerable difficulty in meeting these standards (Jankowski, and Babbitt, 1989).It is well known that metal miners subjected to respirable dusts high in quartz have a higher incidence of silicosis than those exposed to dust low in quartz. However, the role of quartz in the development of coal workers' pneumoconiosis is still a highly controversial question, in spite of the large number of research projects devoted to this subject over the last 20 years. Because coal seams contain less quartz than metal ores and quartz often comes from sources outside the coal seam (e.g., roof and floor), it is difficult to relate studies that deal with the quartz content in coal seams and the incidence of coal workers' pneumoconiosis. Hamilton, Ogden, and Vincent (1983) have provided a plausible explanation for the incidence of the disease by hypothesizing that the quartz content does not affect the probability of developing pneumoconiosis until some threshold value (generally thought to be about 10%) is exceeded.The objective of the research studies summarized here was to obtain a better understanding of quartz occurrences in airborne coal mine dust by studying the variations of the quartz levels in different dust sizes and the relationship between the quartz content in airborne coal mine dust and the quartz content in the mined material. The implications of the results to control of dust in high-quartz sections will also be discussed."

Mar 1, 1992

By Floyd G. Anderson

The Federal Bureau of Mines promotes the use of safe and effective dust-collecting devices for rock drilling in coal mines. To insure that such devices are available to the coal-mining industry, the Bureau issues certificates of performance for dust-collecting systems and certificates of approval for dust collectors and rock drills or other mining equipment with integral dust-collecting systems that meet the requirements of an established Schedule.4/ Investigations are conducted under the provisions of the current revision of this Schedule by engineers of the Branch of Health Research. This circular describes briefly the requirements and procedure for obtaining certificates of performance or approval and lists equipment that has been certified as permissible under Schedule 25 or its revisions as of January 31, 1961. The names and addresses of companies to which certificates have been issued are listed alphabetically at the end of this circular.

Jan 1, 1961