Search Documents

By D. J. Judy, D. J. Rabovsky, W. H. Pailes, V. Castranova, K. Van Dyke, J. Rabovsky, N. A. Sapola, M. McPeek

"Platelet activating factor (PAF) can be released from pneumocytes following exposure to occupational dust (Am. Rev. Respir. Dis. 135:83, 1987). In addition, PAF has been shown to induce pulmonary inflammation, edema, and bronchoconstriction (Hosp. Prac. 19, 67, 1983). This investigation reports the effects of PAF on the properties of three types of cells found in the lung. PAF (1-100, K1/2 = 2.5 pH) caused depolarization of neutrophils as well as generation of chemiluminescence and secretion of hydrogen peroxide. These responses were dependent on the presence of extracellular sodium. However, PAF did not alter oxygen consumption of neutrophils. Although PAF (10 uM) caused depolarization of alveolar macrophages, no stimulation of chemiluminestence, superoxide secretion, or oxygen consumption was observed. However, PAF (10 uM). did potentiate chemiluminescence and superoxide secretion in response to zymosan (2 mg/ml) by 55% and 36%, respectively. In addition, PAF (10-90 uM) caused aggregation of alveolar macrophages. PAF (2-10 uM) also caused depolarization of type II cells, but did not affect membrane integrity or oxygen consumption. However, PAF (10-18 PM) enhanced the activities of two distinct forms of cytochrome P-450 in type II cells and caused aggregation of type II cells at PAF doses above 18 uM. These data indicate that PAF can affect the secretory activity of pulmonary phagocytes and the ability• of type II cells to detoxify foreign compounds (Bureau of Mines Grant - G1175142).INTRODUCTIONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acetylsn-glycerol-3-phosphoryl choline) which has been shown to Mediate a broad range of biological activities (1-3). Its pulmonary actions include contraction of pulmonary tissue (4), secretion of leukotrienes from leukocytes (5), airway constriction (6), pulmonary edema (7), and enhanced migration of neutrophils into the airspaces of the lungs (8,9).PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin (10-13). Therefore, PAP may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of PAF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type II epithelial cells."

Jan 1, 1988

By G. St. J. Perrott

Through the development of manufacturing processes whereby ethylene glycol can be made on a large scale; ethylene glycol dinitrate is now being used in high explosives (dynamites and permissible explosives) by some manufacturers as a low-freezing ingredient of the "explosive oil" instead of such compounds as nitropolyglycerin and nitrosubstitution compounds. The amount of ethylene glycol dinitrate being used constitutes 25 to 50 per cent of the oil. The purpose of this report is to give the results of toots, to determine the effect on the safety and physical properties of permissible explosives of subsituating 25 peg cent of ethylene glycol dinitrate for an equal amount of nitroglycerin or a mixture of nitroglycerin and nitropolglycerin.

Jan 1, 1929

By R. O. Dannenberg

This Bureau of Mines report describes the results of research to develop a process for recovering additional beryllium from a commercial mill waste product, fluoferrate leach residue. Forty-five percent of the total beryllium in the leach residue was recovered in a beryllia product assaying over 98 pct Be0 by a process comprising (1) leaching with 1 N sulfuric acid, (2) adjusting the acidity of the leach liquor to pH 2, (3) extracting the beryllium with di-2-ethylhexyl phosphoric acid (EHPA), (4) stripping the loaded extract with sodium hydroxide solution, (5) boiling the sodium beryllate strip solution to precipitate beryllium hydroxide, and (6) calcining the beryllium hydroxide. Calculated reagent requirements per pound of Be° recovered by a proposed flowsheet were 28.1 lb sulfuric acid, 0.04 lb flocculent, 0.15 lb EHPA, 0.06 lb isodecanol (IDA), 0.22 gal kerosine, and 6.3 lb sodium hydroxide.

Jan 1, 1966

By P. F. Sands, Michael Sokaski, M. R. Geer

The purpose of this investigation was to determine the advantage of using either a conventional sieve bend ahead of a vibrating screen or of attaching a sieve - bend screen surface onto a vibrating screen to serve as a scalping deck when dewatering or draining dense medium from fine coal . In dewatering , use of either the sieve bend or scalping deck increased the capacity of the vibrating screen tenfold and the recovery of coal finer than 0.5 mm threefold , with no sacrifice in the moisture content of the oversize product . In dense -medium drainage , either the sieve bend or the scalping deck reduced the amount of magnetite retained on the product of the vibrating screen , particularly when the medium was as dense as that characteristic of the underflows from dense - medium cyclones . The sieve bend was slightly superior to the scalping deck in dewatering , but the scalping deck was clearly superior in dense -medium drainage . Additional advantages of the scalping deck are lower cost and a substantial saving in headroom.

Jan 1, 1963

By R. K. Koch

The Bureau of Mines produced several series of titanium castings in order to investigate the feasibility of producing commercial-grade titanium castings in bentonite-bonded olivine or zircon sand molds. The use of these molds for titanium casting was investigated as a possible alternative to the industrially used rammed graphite process. Parameters investigated were mold mixtures, mulling, gating, venting, drying, and mold washing. The investigators found that castings with superior ductility and fatigue life, compared with rammed graphite castings, could be made by fume-free pro-cesses in molds bonded by western bentonite, using either olivine or zircon sand. Zircon molds were satisfactory for both light-and heavy-sectioned castings. However, olivine molds were suitable only for light-sectioned castings because the mold-metal reaction became excessive during the pouring of heavy-sectioned castings.

Jan 1, 1981

By K. K. Kelley, L. B. Pankratz, W. W. Weller

Mullite is a substance of prime importance in ceramic technology . Despite this fact , its thermodynamic properties have received little attention . A Bureau of Mines literature survey disclosed the absence of lowtemperature heat capacity data , the absence of an experimental entropy value for 298.15 ° K , and the lack of heat content data beyond the temperature range from 298° to 576 ° K. Data supplied in this Bureau report fill these gaps in the thermodynamic knowledge of mullite . According to equilibrium phase studies of Aramaki and Roy ,3 the mullite phase melts congruently at 2,123 ± 15 ° K , and the equilibrium crystallinephase composition extends from Al Si2013 to Al6.8 Si₂ Q4.2 . The results in this report are for the stoichiometric composition , Al Si¿Qз . • Heat capacity measurements were made over the temperature range from 50 ° to 298 ° K , and the entropy at 298.15 ° K was evaluated . Heat content measurements covered the temperature range from 298 ° to 1,800 ° K. Heat content

Jan 1, 1963

By W. L. Anderson

Standard tellurium analytical procedures were modified to obtain the greater sensitivity needed to support a survey of tellurium resources by the Bureau of Mines. Resulting volumetric and spectrophotometric methods for determining tellurium in all types of tellurium-containing materials are described. Sample decomposition and preliminary separations of interfering selenium, gold, and silver are the same in both procedures. The volumetric method is applicable to samples containing a minimum of 10 parts per million of tellurium, In this method the tellurium is reduced to elemental form, and the colloidal suspension is titrated with 0.01 normal iodine solution. The weight of sample for analysis, from 0.25 to 10 grams, should be selected so that the sample contains 0.1 to 5 milligrams of tellurium. To insure accuracy, duplicate samples should be run and the results averaged, particularly on samples of low tellurium content: The limit of determination is 0,001 percent tellurium, which is equivalent to 0.1 milligram of tellurium when using a 10-gram sample. The spectrophotometric method is particularly applicable to low-tenor materials containing from 0.5 to 50 parts per million of tellurium. Up to 10 gram samples are required for making accurate determinations in the low-concentration range. The sample used should contain between 5 and 100 micrograms of tellurium. The turbidity of a colloidal suspension of tellurium prepared from such a sample is determined in a spectrophotometer .t at a. wave-length of 440 millimicrons, and this value is compared with those of standard samples containing known amounts of tellurium.

Jan 1, 1963

By R. R. Sayers

The effect of comparatively low concentrations of carbon monoxide for short periods and under normal air conditions.of temperature and humidity , with the subject at rest , was studied by Dr. Yandell Henderson and his co -workers . In making recommendations to the New York and New Jersey tunnel commissions * he advised that , if the New York New Jersey vehicular tunnel be so ventilated that persons passing through the tunnel would be exposed to not more than 4 parts of carbon monoxide in 10,000 parts of air for not longer than 45 minutes , they would experience no ill effects . supplementary experiments , carried out by us in connection with our studies at the Bureau of Mines experiment station at Pittsburgh, substantiated this advice . ** In continuing our studies on low concentrations of carbon monoxide , we made a few experiments in a gas chamber where the conditions could be accurately controlled . The factors investigatel were : ( 1 ) The effect of long exposure in low concentrations of carbon monoxide ; ( 2 ) The effect of strenuous exercise ; ( 3 ) The effect of high temperature and humidity in low concentrations of ccarbon Lonoxide .

Mar 1, 1922

By Don M. Coulter

"INTRODUCTION The district comprising Union, Lafayette, Pontotoc and Calhoun Counties, Miss. (fig. 1), was examined in October 1941 by R. W. Smith of the Bureau of Mines, accompanied by J. W. Adams of the Mississippi Bauxite Co. 3/ Subsequently, geologists of the Federal Geological Survey made a more detailed study of the area. 4/Bauxite had been reported as present in several localities in Pontot. County, and large deposits of kaolin are known in Pontotoc, Union, Calhoun, and Lafayette Counties. Many of the bauxite deposits, such as those on Big Hill, Second Hill, and Third Hill, in Pontotoc County, form the caps on hills and are outliers of Wilcox deposits on the Midway formation. Such deposits could have no extensions because of erosion and were not examined, as they were investigated by the Mississippi Geological Survey. 5/ Most of the bauxite was known to be low-grade, with a high iron content. However, Pontotoc County in particular presented possibilities of finding high-grade bauxite with a low iron content by drilling down the dip from the Wilcox-Midway contact. Consequently, with few exceptions the investigation was confined to drilling in this direction.Headquarters were established in Tupelo, Miss., on July 13, 1943, and mineral agreements were obtained covering 8,367 acres of land, with 62 land-owners in Pontotoc and Union Counties. Holes were drilled on properties of three of the landowners in Union County and 36 in Pontotoc County."

Apr 1, 1948

By K. E. Tame

As part of a Bureau of Mines survey of radioactive waste disposal , a laboratory investigation was made to study such problems in carbonate leaching mills . Because uranium concentrators employing carbonate leaching with caustic precipitation normally recycle barren solutions to the washing circuit , the disposal of liquid radioactive wastes is automatically controlled . However , it was deemed important to determine the actual radium 226 concentrations occurring in this type of milling so that the survey of the entire industry would be complete . The laboratory procedure consisted of leaching the ground ore at 85 ° to 90 ° C and 50 pct solids for 6 hours in a sodium carbonate - sodium bicarbonate solution . The pulp was filtered to obtain a pregnant solution that was reacted with sodium hydroxide to precipitate the uranium as sodium diuranate . Regeneration of the barren solution was accomplished by gassing with carbon dioxide . The solution then was reused by advancing the solution through the washing to the leaching operations . The radioactivity in the pregnant solution was unusually high , averaging 6,500 disintegrations per minute ( dpm ) of radium 226 per liter . However , over 95 pct of the radium was precipitated with the uranium . Consequently , no buildup of radium occurred upon reuse of the barren solutions for washing .

Jan 1, 1964

By R. Barany

The heats of formation of anhydrous ferric sulfate and anhydrous indium sulfate were determined by solution calorimetry. At 298.15° K the heats of formation from the metal, rhombic sulfur, and oxygen were -615.6 ±O.7 kcal/mole for ferric sulfate and -649.6 ±O.6 kcal/mole for indium sulfate. Heats of decomposition at 298.15° K are given for the reaction that forms metal oxide, sulfur dioxide, and oxygen) and for the reaction that forms the metal oxide and sulfur trioxide.

Jan 1, 1965

By W. W. Simpson

The Bureau of Mines conducted research to determine the effects of potassium trithiocarbonate (KTTC), a degradation product of potassium ethylxanthate (KEX), on flotation of chalcopyrite and molybdenite. Small amounts of KTTC were identified in fresh and aged solutions of KEX using thin-layer chromotography. Hallimond tube flotation tests on pure minerals showed that KTTC acts as a weak collector for chalcopyrite. Both KEX and KTTC tend to depress molybdenite, but the depression effect is easily overcome by addition of a small quantity of fuel oil. The results of the Hallimond tube tests were confirmed in batch flotation tests using a porphyry copper ore.

Jan 1, 1983

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"An electro-optical method was used to quantify superoxide (SO) release from single rat pulmonary alveolar macrophages (PAM) exposed in vitro to respirable quartz and kaolin dusts and in vivo to quartz. Release was determined by measuring the reduction of nitroblue tdrazolium (NBT) to a diformazan precipitate at 550 nm from video-recorded images of individual cells. In vitro exposure to 0.025 or 0.05 mg/ml kaolin for 40 minutes resulted in no significant differences in either the total diformazan produced (max) or the maximum rate of diformazan production (R)./n vitro exposure to 0.025 mg/ml c1uartz decreased max 38 percent while no significant change was found using 0.05 mg/ml. However, R was decreased 31 percent and 24 percent for the low and high dose, respectively. In contrast, PAM obtained from animals exposed in vivo to quartz dust for two or four weeks in inhalation chambers exhibited increased production of diformazan. However, only PAM analyzed three days post-exposure showed significant increases, while PAM from animals sacrificed ten or 31 days post-exposure were not significantly different from control. The combined in vitro and in vivo quartz results might suggest that there is an initital acute response to exposure that decreases the ability of PAM to produce SO, followed by recruitment of production of PAM with increased SO producing capability. It appears that removal of animals from the source of exposure permits PAM to return to control levels of SO production by31 days. Whether this would be true for chronic exposure remains to be elucidated.IntroductionPulmonary alveolar macrophages (PAM) protect the lungs by phagocytizing foreign debris and bacteria.(1) This process involves ingestion as well as destruction of foreign matter. Phagocytosis usually is accompanied by a respiratory burst which increases cellular oxygen consumption leading to the release of highly reactive oxygen metabolites.(2) These agents have been implicated in the killing of bacteria by phagocytes, but they have also been shown to be toxic and,have been linked to cancer, emphysema, arthritis, diabetes, and other diseases.(3) Toxic effects may be a result of 1) an abnormally low production of metabolites, resulting in damage to lung tissue by the respired bacteria and/or dusts; or 2) an abnormally high production resulting in direct damage to lung tissue by metabolites themselves."

Mar 1, 1989

By D. J. Bauer

A primary amine extraction system was investigated for fractionating a cerium-group, lanthanide sulfate mixture. Addition of diethylenetriaminepenta-acetic acid (DTPA) to the amine extraction system resulted in separation factors as high as 5.4 for lanthanum-cerium, 8.0 for cerium-praseodymium, 3.7 for praseodymium-neodymium, and 7.0 for neodymium-samarium. In multistage studies on a cerium-free lanthanide mixture, 96 percent of the lanthanum was recovered with a purity of 95 percent.

Jan 1, 1968

By Jalna R. Zatko

The Bureau of Mines has developed and constructed an apparatus that is capable of measuring concentrations of high-molecular-weight polymers in solution at 10 ppm and less. A means for determining low concentrations of polymeric solutions was devised that was independent of slight fluctuations in solvent quality in order to measure polymers in effluent prior to recycling of the recovered solution. The concentrations of polymers ore related to a measured pressure drop observed during turbulent flow of the solution. Low concentrations of polymers of ethylene oxide and acrylamide (frequently used as flocculants for clay waste systems) in aqueous and salt solutions have been successfully measured on the apparatus constructed by the Bureau.

Jan 1, 1981

By R. T. DeWoody, W. C. Miller, W. Chester

Studies were made to determine the effect of the shape of a pneumaticrock- drill exhaust muffler on its efficiency, and the origin and reduction of exit noise from the mufflers. Tests of mufflers of three different shapes proved that the shape is not critical and that a muffler could be incorporated into the shell of the drill. Petal diffusers are beneficial in reducing exit noise but add another projection to the machine. Increasing the number of exit openings while maintaining the same area of exit opening has a markedly beneficial effect on the exit noise and appears to be the most satisfactory treatment.

Jan 1, 1964

By Richard A. Winters

In 1985 at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 9,400 acres of the 10,005-acre Duncan Creek Wilderness Study Area (ID-111-78) in order to evaluate the mineral resources. The study area is located in Owyhee County, 10, about 36 miles southwest from Bruneau, ID. No mining districts are in the study area, nor were any mines or claims recorded or found. The southern half of the area was covered by oil and gas lease applications, all of which were cancelled prior to June, 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Duncan Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By R. W. Dalzell

The performance characteristics, efficiency, and operating pressure of jute line-brattice systems were studied under varying underground conditions; various fabric grades and installation methods were used. The test results indicate that line-brattice system efficiency is dependent upon the method of ventilation the method of installation, porosity of fabric, and size of tight rib area.

Jan 1, 1966

By Daniel R. Babich, Jeffrey R. Vipperman, Eric R. Bauer

Prolonged exposure to loud noise can cause permanent damage to the auditory nerve and/or its sensory components. Despite regulations and efforts by government and industry to reduce noise-induced hearing loss (NIHL), it is still a problem in the U.S. coal mining industry. The Mine Safety and Health Administration noise standard (30 CFR3 62), which was enacted in September 2000, is aimed at reducing NIHL in the mining industry. To address NIHL in various aspects of coal mining and provide the necessary information to effectively implement control technologies, the National Institute for Occupational Safety and Health conducted a cross-sectional survey of noise sources and worker noise exposures. Noise surveys consisting of full-shift worker noise exposure (dose) determination, time-motion studies (task observations), and equipment and/or area noise profiling were completed in 8 underground coal mines, 10 surface coal mines, and 8 coal preparation plants. The studies revealed that more than 40% of all workers monitored were subject to noise exposures above 90 dBA TWA8. A summary of these studies is presented, their application to administrative and engineering controls is discussed, and exposure reduction methods are reviewed.

Jan 12, 2006

By James P. Bennett

In this Bureau of Mines study, portions of four acidproof bricks (two red shale and two fireclay) were exposed to 20 wt pct RCI at 900 C for periods of 30 days. Three different techniques were selected to deter-mine volume expansion of these materials after exposure. Linear expansions ranging from about 0.02 to 0.12 pct were noted from Ta pin and dilatometer measurements. The use of strain gages to measure expansions was not successful. The red shale and fireclay brick with the lowest apparent porosities had the lowest expansions. Expansion data obtained by direct measurement of samples exposed for 30-day periods or by dilatometric measurement of autoclaved samples ex-posed for 2 h were comparable. This suggests the use of an accelerated autoclave exposure procedure for determining volume expansion effects of ceramic materials in acid environments.

Jan 1, 1985