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By Ann Hubbs, Vincent Castranova, Jane Y. C. Ma, De-Hwa Chao, Joseph K. H. Ma

AN OVERVIEW OF THE ACTION OF TETRANDRINE ON SILICOSISBecause of the persistent presence of silica dust in the lungs silicosis is a progressive and irreversible disease. At present, there is no proven effective therapy for silicosis. Limited choices of therapeutic intervention with corticosteroids and other immunosuppressive regimens 1,2 have been accepted for some forms of pulmonary fibrosis. These treatments are only minimally effective, and the results provide little understanding of the disease state due to the lack of correlation between drug activity and the mechanism of fibrosis. Thus, continuing effort must be made in the search for effective antifibrotic agents, which may be used to provide a sequential analysis of the fibrotic process and to open the door for further research and clinical development. Tetrandrine is one of hundreds of drugs screened for antifibrotic activity by Chinese scientists. It has been used in China as a treatment for silicosis in open clinical trials3 and in laboratory animals. The action of tetrandrine on pulmonary fibrosis has been attributed to its ability to inhibit particle stimulation of alveolar macrophages, a key cell type central to the fibrotic process, to release oxygen radicals and inflammatory cytokines. Alveolar macrophages (AM) residing on the alveolar wall, are the predominant phagocytic cells of the lungs responsible for pulmonary defense against inhaled microorganisms and other particles and thus play an important role in maintaining the homeostasis of the lungs. 7 Ample evidence suggests that cells of the monocyte-macrophage series play an important role in the immunopathogenesis of pulmonary fibrosis. When upregulated by silica, alveolar macrophages generate reactive oxygen metabolites8·9 which can damage lung parenchyma and release fibrogenic growth factors and cytokines, 10,11 such as interleukin 1 (IL-1), which can induce fibroblast proliferation and collagen synthesis. The cytokine-mediated fibroblast proliferation and collagen synthesis are key steps in the development and progression of pulmonary fibrosis .11 Previous studies by our group have shown that tetrandrine exhibits strong binding affinity to AM and inhibits particle-stimulated respiratory burst activity (oxygen consumption, superoxide anion release, and hydrogen peroxide secretion) in these cells. 13 In addition, studies by Kang et al. 14 have reported that tetrandrine inhibits silica-induced release of fibrogenic factors such as IL-1 which are capable of inducing fibroblast proliferation and collagen synthesis. Reist et al. 15 further suggested that the antifibrotic action of tetrandrine may be mediated in part by the direct effect of this drug on the ability of fibroblasts to respond to proliferative agents. These results indicate that the mechanism of silicosis involves activation of AM and fibroblasts by silica, resulting in abnormal collagen production due to miscommunications between the cell types. Tetrandrine may interrupt this process by direct interaction with the lung cells.

Jan 1, 1998

By Leslie H. Sharp, Martin J. Gavin

"Introduction.Investigations of the oil shales of the State of Colorado were begun February 1, 1920, by the U. S. Bureau of Mines and the State of Colorado, under cooperative agreement entered into by the Bureau and the State, funds for which were provided by the State. The investigations are for the purpose of determining by large-scale Laboratory retorting tests, those conditions which will produce optimum yield of best quality products from Colorado shales. (For an outline of the work and description of the apparatus, see Gavin, Martin J., and Sharp, Leslie H., ""investigations of the Fundamentals of Oil-shale Retorting,"" Reports of Investigations, Bureau of Mines, July, 1920.)In the preliminary work which is usually required when a new material is being dealt with, certain physical and chemical constants of the shales being investigated, and their products, were determined; these data will be of much value not only to the thorough retorting tests now under way at Boulder, but to engineers who will design and construct oil-shale plants. While the figures presented in this report apply only to the shale used in the determinations, strictly speaking, the shale used was selected to represent, as well as possible, an average of the massive type of oil shale encountered in Colorado. The figures, therefore, can probably be applied with little danger of serious error to any massive Colorado oil shale which yields in the neighborhood of a barrel (42 gallons) of oil to the ton.This paper is based on a more complete article now being prepared in which experimental methods are explained in full, and complete experimental data. For the purpose of presenting the data with as delay as possible, it has been decided to anticipate the more complete article with the present report."

Aug 1, 1920

By Edward F. Courtney

Loss of life, loss of sight, crippling injuries, and property damage nearly always result from accidents involving explosives. The severity of such accidents has prompted lawmaking bodies to pass laws concerning the transportation, handling, and use of explosives; manufacturers of explosives publish manuals 'describing explosives and practical methods of handling then; and mining companies and others who use large quantities of explosives publish rules based on actual experience for the guidance of their employees. Careless storage of explosives by thoughtless or incompetent persons, particularly if they are left where children or saboteurs have access 'to them, has led to many serious accidents. Many contractors and mining operators who use explosives are extremely careless about storing them. It is the purpose of this paper to discuss the explosive-handling practices of a large western mining company, which are considered better than most.

Jan 1, 1946

By Theodore Kootz

Manufacture of high-grade ferromanganese; as a rule; requires a low-phosphorus-manganese ore with 45 to 55 percent Mn, chiefly obtained in the Soviet Union, the British Dominions, and Brazil. Also, low-manganese ores have already been used for ferromanganese production, especially in North America .and Germany. During World War I, a process was developed in which a high-phosphorus ferromanganese or spiegeleisen was prepared in the blast furnace from law- or high-phosphorus manganiferous ores, then low-phosphorus manganese slag was prepared by refining under an acid slag, and this material was, worked into a low-phosphorus ferromanganese in the blast furnace.9/ Manufacture of useful manganese ores from a phosphorus-bearing spiegel with 12 to. 15 percent Mn, 4.5 percent C,, and 0.5 percent P by slagging in a refining furnace was reported by Joseph, Barrett, and Wood.10/ The spiegel was refined to 0.75 percent Mn, 3.4 percent C, and 0.45 percent P. Thereby, a slag with about 43 to 58 percent Mn and, about 10 percent Si02, was obtained. Hotter melts gave a smaller phosphorus content in the slag than cold melts. In addition, the phosphorus content of the slag varied with the manganese content of the intermediate metal.

Jan 1, 1952

To restore ventilation and prevent the accumulation of explosive or toxic gases by quickly installing substitutes for stoppings blown down by an explosion. Approach Temporarily replace blown down stoppings with a parachute-shaped brattice which can be erected in minutes. How It Works The self-sealing brattice is secured to the roof, ribs and floor by anchoring its nylon edge strip at several points using extensible poles, shads, or available projections such as roof bolts. The air pressure in the entry pops open the chute of lightweight sailcloth, forcing it tightly against floor, roof and rib. See Figure 1. This emergency brattice has been tested at two locations in the Bureau's Experimental Mine at Bruceton, Pennsylvania. In a test last December, one MESA inspector wearing full rescue apparel (including self contained breathing apparatus) installed a self sealing brattice in an entry at the Bruceton Mine. Although he did not have any previous experience with the device, he easily erected it in slightly less than 10 minutes, using two extensible supports (pogo sticks). Research to improve and refine the self-sealing brattice is continuing.

Jan 1, 1977

By M. M. Fine

"Button" type ore from the Cason mine, Batesville, Ark., can be up-graded to plus-40-percent manganese by mineral-dressing procedures. A simple process including gravity concentration and. magnetic separation yielded more than 50-percent recovery of concentrates containing 38.1 to 40.6 percent manganese. These values in turn could be raised to 41.4 and 42.8 percent, respectively, upon sintering to conform to size specifications. The Bureau of Mines in the past has surveyed and tested many manganese ores and prospects in an endeavor to alleviate the shortage of manganese. The present period of emergency again emphasizes the strategic position of the metal, and manganese investigative work is being stressed to find new ore bodies and to apply newer beneficiation techniques to the known deposits.

Jan 1, 1953

By J. F. Neill, O&apos

[The Cartersville mining district is in Bartow County, Ga., about 40 miles northwest of Atlanta. Barite, limonite, ocher, amber, hematite, and, manganese oxide ores have been produced from the strict since about 1840. In the search for a possible source of manganese ore, Bureau of Mines engineers made a preliminary study of the district from September 1950 to January 1951. During this study 139 deposits were examined, and many mineral exposures were sampled. Manganese mineralization occurs as fine oxide and concretionary pellets in residual clays, as fine oxides in umberous clay, in brown-iron deposits, and in a limited quantity in mud ponds and Jig-tailing piles. The future supply of ferrograde manganese ore from the district, using current mining and benefication methods, appears limited to the recovery of the hard manganese ores deposits. Rough estimates indicate a reserve of manganese-bearing clays of about 8,000,000 long tons. This type of deposit has been extensively exploited and the larger deposits mined out to depths of from 50 to 200 feet. The remainder of these deposits are low grade, are covered with deep layers of colluvium, or lie below the ground-water table. Any future production from this source will require systematic prospecting, improved concentration, and an increase in the price of concentrate.]

Jan 1, 1954

By L. W. Kelly

The purpose of this circular is to show that, under the conditions prevailing in the Stony Point mine, wooden bolts were just as satisfactory as steel bolts or conventional timbering, with a reduction of approximately 80 percent in cost of material. This one fact alone is enough to justify an experiment with wood. This circular will show that production records have remained constant with both wooden and steel roof bolts. INTRODUCTION The successful use of steel roof bolts is now an accomplished fact in the coal industry, but the use of wooden bolts in place of steel is a rarity. The first experiment with wooden roof bolts was mane in 1949 in the Rio Verde mine, Norton Coal Corp., Nortonville, Ky.2/ This experiment was successful; the company obtained excellent results, but operations in the mine were suspended before enough time had elapsed to prove the value of wooden roof bolts conclusively. It is obvious that, if wooden roof bolts could be used in place of steel bolts or conventional timbering-methods, every mine operator would use word, as the cost is only a fraction of the other two methods. The Stony Point experience has proved conclusively that, under certain conditions and with a certain type of roof, wooden roof bolts can be used successfully.

Jan 1, 1952

To reduce the exposure of mining machine operators to respirable dust. Approach: A protective curtain of filtered air is blown down around the operator's head, from a manifold mounted on the machine canopy. How It Works: Mine air is drawn into the system through a filter which removes respirable dust. The filtered air enters a centrifugal blower which pushes it through a flexible hose to a manifold mounted on the canopy above the operator. Air leaves the manifold through a perforated plate and flows down around the operator's head. A photograph of an installed system can be seen in Figure 1. The second photograph, Figure 2, shows the sys-tem components. An important advantage of this dust protection system is that it is not worn or carried, or in any way connected to the operator. It is therefore not uncomfortable, encumbering, or

Jan 1, 1976

By George S. Scott

The Bureau of Mines conducted ignition, flammability, and decomposition experiments on gas mixtures containing ethylene to determine its flammability characteristics at elevated pressures and ambient temperatures. Pure ethylene was found to propagate a decomposition reaction at 1,000 psig and ambient temperatures when ignited with 1 gram or more of guncotton in a 2-inch-id bomb. The decomposition products were primarily carbon, methane, and hydrogen.

Jan 1, 1965

By William Y. Mo

This Information Circular provides a detailed background documentation of how the Bureau of Mines projects U.S. mineral demand to the year 2000. These statistical projections serve as a quantitative basis for contingency forecasting of the low, high, and probable U.S. demand for nonfuel minerals by end-use categories and are published in the Bureau of Mines Mineral Commodity Profiles and Mineral Farts and Problems series. Aluminum is used as an example in this study.

Jan 1, 1980

By F. W. Hoertel

Near-optimum parameters were determined by the Bureau of Mines for vapor deposition of rhenium on heated copper substrates by hydrogen reduction of rhenium hexafluoride (ReF6). High-purity deposits of nearly 90-percent theo¬retical density were obtained with the reaction chamber at 250° C, with an H2 to ReF6 volume ratio of 25 to 1, and with an ReF6 flow rate of 5 grams per hour. Some rhenium deposited as a loose, black powder. When the established near-optimum parameters were carefully followed, this could be minimized but never completely avoided. Varying the reaction chamber pressure, both above and below atmospheric, yielded excessive quantities of rhenium powder. Deposition efficiencies, based on only the coherent metal, ranged between 70 and 75 percent. Massive deposits contained only spectrographic traces of impurities. The average microhardness (Knoop, 100-gram load) of vapor-deposited rhenium was 907. Limited research on the deposition of rhenium-tungsten alloys by reduction of the mixed hexafluorides produced deposits in which linear composition gradients were pronounced; this nonhomogeneity was attributed to the wide variation in optimum hydrogen-reduction temperatures of the two hexafluorides (250° C for ReF6 and 550° C for WF6). Using deposition temperatures between 250° and 550° C did not eliminate the composition variations.

Jan 1, 1967

By A. W. Ambrose

"Introduction.Oil-field operations have often been carried on under great stress and haste, in which the prime purpose has been to put the wells down rapidly as possible, without regard to a few of the various factors affecting cost. In such fields as Burkurnett, Texas, where the well locations are town lots and other small tracts, the operator was concerned primarily with in drilling. In such cases a few thousand dollars more or less in the cost of a well not considered. We are reaching a time, however, when our reserves a,more definitely outlined and properties are being along more economic lines. Operators are becoming more concerned with the actual cost of this work, and are gradually learning that fuel consumption can be reduced in drilling and producing without delaying the speed of drilling, and in the case of production, it will greatly reduce the unit cost per barrel of production.Types of Field Boilers.In the oil fields there are in general two types of boilers; those which are used for drilling wells and are of a more or less portable character, and those established later in a more permanent form and serve for the purpose,of generating steam for producing the oil. As a rule, the latter type of boilers are larger than those of the drilling type. Usually, little care is given to the installation of drilling boilers; particularly in attempting to set them up in such a way as to avoid waste in of fuel. Because of the temporary nature of these installations there may be some justification for not giving them more,attention in this resend, but it is believed that a few precautions could be taken that would amply repay the cost and trouble taken. In connection with the boiler plants that are afterwards established, when a few producing wells have been,brought in with a life of two to ten years and probably longer, much care to the boiler-plant construction and to the installation of recording instruments which will assist in operating the plant at minimum cost."

Nov 1, 1920

By Victor Kalcevic

A gas-flow retort for thermal processing of oil shale to recover shale oil was developed by the Bureau of Mines at its Oil-Shale Demonstration Plant, Rifle, Colo., from 1948 to 1952. The retort is a crossflow gas-to-broken-solids heat exchanger. The heating medium is the gas produced in the shale retorting process. The gas is heated in specially designed stoves outside the retort and recycled to the retort. Oil shale from the Mahogany ledge section of the Green River formation in northwestern Colorado was the material processed. Indicated maximum oil recoveries for 20-to 25-gallon-per-ton shale in a l2-inch-thick shale bed and a 20-inch bed are 96 and 91 weight-percent of Fischer assay, respectively. Heat requirements for maximum recovery are 600 to 750 B.t.u. per pound of shale. Properties of the recovered shale oil are affected slightly by shale-bed thickness and extent of retorting. Oil recovery from oil shales assaying over 30 gallons per ton is lower than that from leaner shales.

Jan 1, 1959

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 Jay W. Hawkins

Under an approved remining program, mine operators can remine abandoned coal mines without assuming legal responsibility for treatment of the previously degraded water, as long as the discharging waters are not further degraded and other regulatory requirements are satisfied. A U.S. Bureau of Mines review of 105 remining permits in Pennsylvania indicates that remining results in substantial reclamation of abandoned mine lands, utilization of significant quantities of coal, and reduction of contaminant loads (acidity and iron) from degraded mine drainage discharges. Normality tests performed on the water quality and flow data indicate generally nonnormal distributions and extreme right-skewness, tending toward lower values. The water quality of underground coal mines was observed to be more highly degraded in terms of acidity, iron, and sulfate than that of surface coal mines. The optimum baseline sampling scenario is 12 months in duration at a frequency of one sample per month. Analysis of water quality and flow rates before and after remining indicates that a majority of the mines exhibited either no change or a significant decrease in pollution rate because of remining. The discharge flow rate was the dominant controlling factor when the post-remining contaminant load was significantly better or worse than the baseline (pre-remining) load.

Jan 1, 2010

By Milford L. Skow

Utilization of domestic ores in the winning of metallurgical alumina requires a convenj.ent method of treating siliceous bauxites and other aluminous materials. In the United states there are only small reserves of high-grade bauxite but considerably larger tonnages of low-grade material. In addition, there are large deposits of high-alumina clays. If these high-silica bauxites or high-alumina clays could be beneficiated, either by are dressing or by chemical dissolution to remove a large proportion of the silica, then the potential reserves of aluminum ores would be increased materially. Faced with a similar situation, the German industry, chiefly dependent on high-grade French bauxites prior to World War II, was compelled during the war to Use lower-grade ores. For desilicating the lower-grade bauxites before the Bayer treatment, a method was developed in which the bauxite was calcined and then given a dilute caustic leach preliminary to the pressure digestion. It was planned to regenerate the caustic by treatment of the desilication liquor with lime. As European bauxites are mineralogically different from those found in this country, preliminary work was undertaken to determine whether this process might be applied to domestic materials. The results of this work, along with a review of the German process, are presented in this report.

Jan 1, 1950

By Liming Yuan

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Jan 1, 2009

By J. R. Hauger, P. A. Romans, W. J. Niebuhr

With suitable instrumentation and techniques it is possible to determine the presence of tantalum in columbium to 20 ppm . This paper discusses the selection of X- ray spectrographic instrumentation and describes a technique for accomplishing the low level determination of tantalum . An ion- exchange method of separating tantalum from columbium is also described .

Jan 1, 1964

By Robert H. Merrill

This report contains a summary of the various studies made to determine the structural design of the production mine area of the Oil-Shale mine, Rifle, Colo. Prior to this investigation, it had been determined from a study of the geology, the structure of the deposit, and mining costs that the deposit should be mined by open stoping. The problem remained to determine the maximum safe roof span, the optimum extraction ratio, and the size of the pillars. These factors were determined from a study of the geologic structure of the deposit, the physical properties of the oil shale, and the magnitude and distribution of the stress around proposed underground openings. The latter was determined from both theoretical calculations and model studies. Safe roof spans, pillar sizes, pillar contours, and optimum extraction ratios were calculated from elastic theory and the physical properties of the mine rock. Safe roof spans, pillar sizes; and time effects were determined by Wright and Bucky by testing mine models in a centrifuge. The models were made from rock specimens taken from the proposed mine roof and pillars. The results from both studies agreed.

Jan 1, 1954