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By Doug Scott

Develop tools that companies can use to comply with 29 CFR 1910.1200.

By N. S. Dalal, Xiaoya Sun, Xianglin Shi

"The in vivo toxicity of vanadium(V) has been found to correlate with the depletion of cellular glutathione and related non-protein thiols. With a view to understanding the mechanism for this observation, we have investigated the oxidation of glutathione, cysteine N·acetylcystcinc and pcnicil· lamine by vanadium(V), using electron spin resonance (ESR) and ESR spin trapping methodology. The spin trap used was 5,5-dimethyl-l-pyrroline I-oxide (DMPO). It is found that the oxidation of these thiols by vanadium(V) generates the corresponding thiyl radicals and vanadilim- (IV) complexes. The results suggest that free radical reactions play a significant role in the depletion of cellular thiols by vanadium(V) and hence in vanadium(V) toxicity. 1. INTRODUCTIONThis communication reports on the identification of thiyl radicals formed as intermediates in the reaction of vanadium(V) with glutathione (GSH) and related nonprotein thiols. This study was undertaken because the biochemical mechanism of vanadium toxicity is still not fully understood,. despite being a topic of current research activity [1-20). As to possible clues, it is known that vanadium is most toxic when administered in its pentavaient state [21), and that vanadium(V) administration into laboratory mice reduces cellular levels of NAD(P)H and GSH [22). While the oxidation of NAD(P)H by vanadium has been studied extensively [16-20), that of glutathione and related non-protein thiols has been paid less attention. On the other hand, GSH and related thiols are important cellular antioxidants [23). Their functions include decomposing lipid peroxides and protecting cell membranes [23-25). Thus any reduction in the cellular contents of such nonprotein thiols after vanadium exposure may result in the accumulation of lipid peroxides which might ultimately lead to tissue injury. With a view of finding the mechanism for this thiol depletion process, we have investigated reactions of non-protein thiols with vanadium(V). Particular attention has been paid to the detection of thiyl radicals, since it has been postulated [l] (but not experimentally proven) that the glutathionyl radical (GS·) might be an intermediate in the reaction between vanadium(V), NADH and GSH. We have used electron spin resonance (ESR) and ESR spin trapping methodology for investigating the reactions of GSH, cysteine, N-acetylcysteine and penicillamine with vanadium(V). The results show that the corresponding thiyl radicals are indeed formed in the one-electron reduction of vanadium(V) by all of the above mentioned thiols."

Jan 1, 1990

By K. J. Maggs

The U.S. Bureau of Mines has investigated the chemical vapor deposition of diamond films on tungsten substrates. The effects of deposition parameters on the adhesion of the films was determined. The films were produced using a hot filament chemical vapor deposition system. Parameters investigated were substrate temperature and methane concentration in the feed gas. Film quality, morphology, and composition were characterized by scanning electron microscopy and Raman spectroscopy. Adhesion testing was performed using an indentation technique, and the results were quantified by relating adhesion to interface fracture toughness. Diamond films with well-faceted crystalline morphology with grain size greater than 1 µm had poor adhesion properties regardless of substrate temperature or methane concentration. Diamond films with smooth morphologies consisting of rounded clusters of small (<0.2 µm) diamond crystallites and amorphous carbon phases displayed much higher adhesion, although the conditions that led to the growth of these films are not understood.

Jan 1, 2010

By L. C. George

Addition of an acid waste to an alkaline cyanide waste was investigated for five different combinations of electroplating wastes. At the optimum final pH values of the mixtures, metals and cyanides were almost quantita¬tively precipitated. No evolution of hydrogen cyanide was detected by a few additional processing steps, significant amounts of variable metals were recovered for recycling the waste-plus-Waste step is attractive because no reagents are required, metals arc concentrated, and a relatively harmless effluent that meets most water quality Standards for cyanide content is produced.

Jan 1, 1970

By John Nagy

Experience and research have shown that an effective way to reduce structural damage from explosions is to provide adequate pressure-relief vents in the walls of equipment and buildings within which explosions might occur. In general, free or unrestricted openings represent the most efficient type of vent. However, in many manufacturing operations it is impractical to use free vents, and it becomes necessary to cover the openings with diaphragms or blow-out disks, hinged panels, or other devices, in order to give protection against weather changes, to prevent the efflux of dusts or vapors from equipment during normal operations, or for other reasons. A few data on the pressure-relieving capacities of hinged panels and a paper diaphragm were published in Bureau of Mines Report of Investigations 3924, which covered the first phase of the dust-explosion venting study made by the Bureau. The present report describes recent experiments that were made to determine the relative effectiveness of an unrestricted vent and 22 types of closures, including various paper, cloth, and metal-foil diaphragms, hinged doors or panels, and several kinds of scored and unscored glass panes. The tests showed that many of the vent closures were effective in releasing the explosions rapidly during their incipient stage, so that the development of destructive pressures was prevented. Vents of this type should prove useful in safeguarding industrial equipment from severe explosion damage. The experiments disclosed that the venting capacities of the diaphragms are approximately inversely proportional to their static bursting strengths.

Jan 1, 1950

By Marvin L. Whisman

This report describes the preparation of tritium-labeled organic compounds to be used by the Federal Bureau of Mines in studying the role of certain gasoline constituents in gum-forming mechanisms. The gasoline constituents that have been investigated boil within a range of approximately 90 to 230° C. and can be classified as paraffins. naphthenes, olefins, diolefins, monocyclic aromatics, polycyclic aromatics, and organic sulfur, nitrogen,: and oxygen compounds. The technique of Wilzbach has been applied to more than 50 samples. Purification techniques have been developed that accomplish rapid and effective purification as well as removal of labile tritium in a one-step operation. Data are presented to show the rate of exchange between tritium and hydrogen that can be expected for a variety of compounds common to a full-boiling-range gasoline. These values should be useful to other investigators using tracer programs involving tritium labeled compounds.

Jan 1, 1961

By H. N. Smith

IN 1944 the Congress passed the Synthetic Liquid Fuels Act that authorized the Secretary of the Interior, acting through the Federal Bureau of Mines, to conduct basic research and construct and operate demonstration plants to produce synthetic liquid fuels from coal, oil shale, and other substances. As a basis for the oil shale investigations to be undertaken in this country, the progress of foreign countries in developing and using oil shale as a source of liquid fuels was studied by the technical missions of the Federal Bureau of Mines. Oil shale mines, retorting plants, and refineries were visited; geological information on the nature and occurrence of the foreign oil shales was obtained; and samples of the oil shales were collected where possible. Samples collected by these missions or acquired by other means came from Australia, Brazil, Canada, France, Manchuria (China) , New Zealand, Scot-land, Spain, Sweden, Thailand, and Union of South Africa. These countries represent a large part of the locations where oil shale developments have taken place. The major omissions are the Estonian, German, and Russian developments.

Jan 1, 1959

By A. C. Fielder

It is with some diffidence that I venture to address the Montreal Section of the Society of Chemical industry on the subject of motor fuel from coal at a time when crude petroleum is produced in greater quantities than at any time in history, and at a time when the known reserves exceed all expectations, even the optimistic estimates of the Committee of Eleven of the American Petroleum Institute. Not only are new fields being discovered in America a -an embarrassing frequency but sources outside of the North American Continent show, unmistakable signs of adding materially to the world&apos;s sources of oil. Were it not for the tremendous scientific and technical importance of the work done in the past few years in transforming coal into liquid motor fuels, I should prefer to let this subject rest until a more propitious time, such as prevailed some years ago, when the gasoline consumption curve was rising rapidly and the production curve was slowing in its upward rise. That was the period which stimulated the researches which resulted in tetra ethyl lead and anti-knock gasolines on this side of the Atlantic and in methanol, synthetic gasoline and hydrogenation of coal on the other side. Some of you will recall a symposium on Motor Fuels and Oil Conservation held at the Chemists&apos; Club n New York in September; 1925. Dr. R. L. Brown and I presented a paper at this meeting on "Complete Utilization of Coal and Motor, Fuel, in which we pointed out that coal was the most likely raw material source of gasoline substitutes if and when needed. We grouped the present and future, processes&apos; for obtaining motor fuel from coal in three classes, namely:

Jan 1, 1928

By W. B. Tarpley

This program was conducted to demonstrate the unique advantages of suppressing methane ignition in underground mines by use of Energy & Minerals Research Company&apos;s thixogel fire extinguishing system, which stably suspends dry powder extinguishing agent in thixotropically gelled liquefied gas extinguishant. As anticipated, the project demonstrated thixogel system advantages of: 1) capability to disperse state-of-the-art powders in thixogelled Halons; 2) non-agglomerating stability for dependable expulsion; 3) stability in storage for long shelf life; 4) virtually in¬stantaneous dispersion; 5) expansive cloud formation; 6) reach and re-forming around obstacles; 7) at least twice the extinguishant effectiveness; and 8) compatibility of use with Fenwal bottles and MSHA canisters. Thus, it should prove a superior explosion/fire suppressant for coal face cutters and triggered barriers, as well as for motorized equipment, electrical equipment and the like.

Jan 1, 1981

By H. J. Coleman

Knowledge of the types of naturally occurring sulfur compounds in petroleum is of both theoretical and practical interest to petroleum chemists and geologists. This knowledge has been extended by the identification of 77 sulfur compounds, including 36 thiols, 23 chain sulfides, and 18 cyclic sulfides in a 111° to 150° C boiling range distillate of Wasson, Texas, crude oil. The characterization procedure used in separating and identifying these compounds included isothermal distillation, vacuum fractionation, liquid-solid chromatography (alumina adsorption), chemical treatment, gas-liquid chromatography, microdesulfurization, and infrared analysis. The procedural steps described represent a systematic method of sulfur compound analysis considered applicable for determining the nature and concentration of the sulfur constituents present in any straight-run petroleum distillate of the above-boiling range.

Jan 1, 1966

By W. E. Lamont

The Federal Bureau of Mines, in cooperation with phosphate companies in the Florida land-pebble area, made a comprehensive study of the waste clays, or "phosphate slimes," produced in the mining of phosphate rock in Florida. These slimes represent a significant ecological problem and a major deterrent to effective land recovery in the phosphate-mining areas. Physical, chemical, and mineralogical studies were made of slime samples submitted by 15 of the 16 plants in Florida in an effort to identify factors that prevent successful consolidation of the slimes and subsequent recovery of the mined lands. Results of these studies indicated that the clay mineral attapulgite, a hydrated magnesium silicate, was primarily responsible for the very poor settling characteristics of the slimes, and that the quantity of attapulgite in the slimes effectively controlled the settling rate, pulp density of terminal solids, viscosity, percent solids of filter cake, and flocculant requirements.

Jan 1, 1975

By James A. Wasson

This report analyzes the petroleum-production potential of the basal Greenbrier dolomite zone, Sycamore-Millstone field, Sherman District, Calhoun County, W. Va., through the application of certain secondary-recovery methods. The well logs obtained and the core recovered from a well in this formation permitted an evaluation of the productive capability of the reservoir, Approximately 120,000 stb of oil may be produced from a 20-acre five-spot unit at breakthrough if the property is waterflooded. At an assumed limiting producing gas-oil ratio of 20)000 sef/stb, approximately 69,000 stb of oil should be recovered by low-pressure gas drive.

Jan 1, 1967

By L. E. Schultze

Experiments were conducted by the U.S. Bureau of Mines to verify enhancements due to chloride and surfactant additions in the leaching system of chalcopyrite with ferric sulfate and sulfuric acid. A statistical experimental design was used and equipment was designed to eliminate contributions from changes in solution electrochemical potential during the course of the measurements. Results confirmed that chloride additions increased chalcopyrite leaching by as much as 94 pct over the electrochemical potential versus hydrogen electrode range of 630 to 750 mV at pH 1.7 and 50°C. Total iron concentration had no effect over the range of 1 to 5 g/L. The effect of surfactant addition was less well defined. While additions of LA 790 (a polyoxyethylene lauryl ether) resulted in increased copper leaching in several of the tests, the differences were too small to be statistically significant. No interaction effect could be verified.

Jan 1, 2010

By Natesa I. Jayaraman

This report describes recent improvements the Bureau of Mines made in the design of its shearer-clearer water-spray system for dust control on lonwgall shearer faces. The improvements were based on findings from a field survey of six mines and laboratory test results. The report in-cludes information on installation and use of the improved shearer-clearer system and describes a field installation and 3-week underground test of the system. The improved shearer clearer, like its predecessor, reduces dust concentrations in the shearer operator&apos;s walkway by splitting the airflow on the upwind side of the shearer and confining the dust cloud to the face side of the shearer. The improved shearer-clearer system utilizes more practical-mounting locations for the water sprays and requires less water consumption. In the underground test, the improved system maintained the clean-air split in the walkway up to 40 ft downstream from the shearer. To further improve dust suppression, cooling-water manifolds were relocated into the loading zone. The laboratory and underground tests showed that the improved shearer-clearer system and the techniques described can significantly reduce the respirable dust exposure of shearer operators from shearer-generated dust.

Jan 1, 1985

By John S. Dunning

This paper is one of a series describing methods and costs of recovering sand and gravel from deposits in the United States and deals directly with the operations of the Atlas Sand, Gravel and Stone Co. at Farmington, Conn. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local expenditures only and not total production costs. It is recognized that publication of total costs might in some instances cause embarasement to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations may ensue.

Jan 1, 1933

By R. H. Nicholas

Shuttle cars have undeniably proved their worth as a means of transporting coal underground; however, several factors have arisen in connection with their possible improvement. This report .discusses the effect of shuttle cars that employ rough-tread and smooth-tread tires on mine roadbed, the amount of dust thrown into suspension by the use of such tire treads, and the service rendered by each type of tire. Involved, also, in this study are observations on the use of different amounts of calcium chloride on the haulageways.

Jan 1, 1949

By R. P. Walters, M. J. Lynch, D. R. Flinn

The Bureau of Mines evaluated tthhee feasibility of substituting platinum- coated metals for bulk platinum shapes as a means for conserving platinum . Platinum coatings were prepared using four different methods of electrodeposition , then tested and evaluated . In order for platinum coatings to be useful in process environments , they must be thick , adherent , stress - free , and pore - free . The Bureau evaluated direct - current , current reversal , cathode shielding , and pulsed- current plating techniques for producing a pore-free platinum electrodeposit from a molten cyanide bath . Aqueous corrosion tests of Fe - 10Cr substrates coated with approximately 25 μm of platinum showed that pulse plating yielded the most corrosion- resistant and , hence , the most pore -free coatings . The morphology of coating cross sections was in all cases columnar . The average grain size of pulse -plated deposits was independent of thickness , while all other plating techniques produced grains that increased in size as the coatings became thicker . It is believed that the constant grain size in the pulse - plated deposits resulted from better mass transport during the electrodeposition .

Jan 1, 1965

During 1990-1999, a total of 458 fires occurred in all coal mining categories; 157 of those fires caused 164 injuries and 2 fatalities. The greatest number of fues and fire injuries occurred at surface mines, whch also had the highest risk rate values. A total of 66 fuefighting interventions were required. Of these, there were 25 mine rescue team interventions in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department interventions at all surface operations, including 19 mobile equipment interventions. In all, 50 fires destroyed or heavily damaged equipment (including 16 pieces of mobile equipment) because of failure of other firefighting methods, late fire detection, undetected fires, or fire size. A total of 1 14 fires were detected late by smoke, and 42 fires were not detected.

By L. C. IlsLey

Through the cooperation of the Pennsylvania Department of Mines the writer obtained from State, records detailed information concerning coal-mine accidents occurring in Pennsylvania bituminous mines during 1939, particularly those nonfatal accidents in which the injured person lost 60 or more days? time from mark. The writer wishes to acknowledge assistance received from Pennsylvania State officials, especially Richard Maize, secretary of mines, and. Joseph J, Walsh, deputy secretary of mines; also to Thomas Dickinson,3/ of the Bureau of Mines, who rendered valuable assistance in assembling the data an the several tables.

Jan 1, 1941

By Richard N. Spencer

This report describes investigations of the economic merits of multiple zone mining and beneficiation versus selective mining of altered Western phosphate rock. The same deposit was considered in both instances and it was assumed that the grade of selectively mined ore was comparable to the grade of the concentrate from beneficiation. The beneficiating scheme used for the investigation was one proved by small continuous circuit operation. All economic factors were found to favor multiple zone mining plus beneficiation. Capital requirements and production costs were lower, and production life of the deposit was extended 4.5 times. The concentrate from beneficiation would be a uniform high-quality feed for acidulation and would be low in stable metallic oxide (R203) content. Such a feed would permit improved plant operating control, and the low R203 would promote more rapid filtration and minimize sludge formation in the phosphoric acid. With the proposed treatment, the concentrate produced by flotation from this deposit would cost about 1.5 times as much per ton as the concentrate produced by classification sizing. Therefore, inclusion of a flotation step in treatment schemes requires an economic analysis for each ore deposit.

Jan 1, 1971