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By Oliver Bowles

The use of fire as a source of heat was the first step from primitive existence toward modern civilization, and heat has performed functions of inestimable importance throughout the ensuing ages. The first commercial steam engine invented in 1698 demonstrated that heat was an important source of power, and heat has since become the motivating force for railroad trains and steamboats as well as for machines in multitudes of factories. Aside from its function of supplying power, heat is an agent of vast importance in chemical reactions and engineering processes. Because of the high temperature of steam under pressure, losses by radiation from boilers and pipes become excessive unless the radiating surfaces are covered with insulating materials. Insulation is important also for hot-water pipes and many other types of equipment from which heat may radiate. Radiation losses from heated surfaces increase rapidly

Jan 1, 1943

By John C. Machisak

Employment and related injury experience of the coking industry in the United States for 1956 contained in this publication is summarized under three general sections: (A) General injury experience: Tables 1 to 9: Current and comparable statistics on operating data, number, frequency, and degree of severity of injuries and major accident agencies involved in the cause of injuries. Data are presented for the industry as a whole, for each type of oven, and for the States in which coke was produced. (B) Selected injury experience: Tables 10 to 15: Comparable injury data covering 5- and 10- year periods on the number and degree of severity of injuries and major accident causes.

Jan 1, 1958

By William C. Smith

Roof support, an important aspect of ground control, involves maintaining roof competency to ensure a safe and efficient mining environment. Wide variability in rock quality and stress distributions requires a systematic approach to roof support design that satisfies specific goals. The success of past roof sup-port in reducing the incidence of roof falls has been primarily attributed to safer roof bolting practices. However, roof falls continue to be the number one occupational hazard in underground coal mines. This U.S. Bureau of Mines report presents a general overview of roof bolting and other roof support methods used in the United States. Characteristics of bad roof and associated roof failure theories are briefly presented as background to roof support. Methods of detecting and monitoring roof behavior and/or bolt performance provide essential feedback on roof support requirements. A discussion follows on roof bolt design that assimilates roof and support parameters into useful equations or nomographs to help decide what bolt types to use and how they should be installed under different roof conditions.

Jan 1, 1993

By David E. Siskind

A Bureau of Mines survey of noise from quarry production blasting was conducted at seven crushed-stone quarries, providing information on close-in noise generation, comparative instrumentation, and evaluation of the sound levels as related to blasting parameters and existing State and local noise standards. The results from this preliminary survey will be useful in the design of a complete investigation of the problem of noise from blasting. There exists an immediate need for technical guidelines for noise pollution control agencies presently working on the regulation of impulsive noise sources. This survey and results from previous work by other researchers are used to derive interim recommendations on weighting scales, generated sound levels, and instrumentation. These recommendations are based on the limited data presently available and may be modified with subsequent investigation of noise generation, propagation, structural damage, and human tolerance.

Jan 1, 1974

By Jim Ploger, Peter W. Johnson

Bus drivers represent a large segment of the US transportation industry and research has shown an association between exposure to Whole Body Vibration (WBV) and the high rates of low back disorders. Impulsive WBV exposures have been recognized as a risk factor for low back injury and new guidelines exist for their measurement and assessment (ISO 2631, Part 5). Methods to accurately and better characterize the impulsiveness of WBV along with the temporal patterns of the exposures are needed. The development of a hardware and software system to measure continuous TWA and raw, impulsive WBV exposures and the design of a subsequent study are presented. Methods Using two Larson Davis HVM 100 as accelerometer amplifiers, small external batteries, and a Pocket-PC (PDA) with 1 Gb of compact flash memory, we can collect up to 16 channels of data for a full day 600 Hz. Tri-axial WBV exposures will be measured and characterized at the frame of the bus and at the driver/seat interface (seatpad accelerometer). Using a repeated measures design, 20 bus drivers will drive on selected routes which include both city streets and highways, and within and between subject components of variability and exposure determinants related to the bus, bus seat, the bus driver, and the route will be identified. Global Positioning System (GPS) data will also be collected and integrated with the WBV exposure data to facilitate the identification of the location, velocity and type of road associated with high average TWA and impulsive WBV exposures. This system may be used to develop administrative (alter speed and/or route of bus, systematically vary type of routes) and/or engineering controls (identify and trigger the need for street repair) to reduce high WBV exposures. Results Our portable Pocket-PC based data acquisition system is up and running and we can collect seven channels of WBV data (seat pan tri-axial accelerometer, bus frame tri-axial accelerometer and GPS data) continuously for a full shift. The software analysis of the data is complex but nearing completion. We have incorporated the vibration dose calculations from ISO 5321, Part 5 and have obtained a Matlab-based routine to appropriately weight the continuous signals. Discussion In summary, the measurement of WBV is complex but new technologies open avenues of collecting and assessing WBV exposures that were previously not possible. The standardization of impulsive WBV exposure assessment methods is needed to further the discipline and better enable comparisons across studies.

Jan 6, 2006

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By J. H. East

Potash is one of the essential chemicals used in fertilizing soil deficient in natural minerals . Europe uses a large tonnage of potash in the form of easily soluble salts , and this is particularly true of those countries where the natural minerals in the soil have been exhausted owing to intensive cropping of the land . The application of potash to the soil in these countries is essential if normal crops are to be obtained ; during the war , some European countries were unable to obtain sufficient potash , and productivity of the farming areas declined seriously . • The largest -known deposits of potash in the world ; with the possible. exception of Russia , occur in Germany , and the German output of processed salts constituted about 65 percent of world production prior to the war . The German potash-plant installations are large , modern , brick and steel construction and apparently built for a planned operation of many years . Two districts produced approximately 80 percent of the German potash; the Werra -Fulda district , near Vacha , had the largest production , and the Sudharz district , near Nordhausen and Sonderhausen , was second . (Fig . 1. ) Hannover and Stassfurt were two smaller producers . Potash fertilizers are rated in terms of potassium oxide (K20 ) . The usual basis for calculation of production or application of the salt is to reduce the potash content to 40 percent K₂0 .

May 1, 1947

By H. Kenworthy

Small batches of fluorspar flotation concentrates were made into nodules and pellets on a laboratory scale. Several of these were rated acceptable by laboratory evaluation methods. The most satisfactory pellets were produced by mixing fluorspar with about 12.5 percent of water, by weight, and 4 percent of organic binders. These binders) for the most part) originated from petroleum and wood-pulp industries. They were generally difficult to handle and were not easily incorporated with the fluorspars tested. Most of them seemed to have an aversion for damp fluorspar and had to be forcibly mixed with the fluorspar; which was then formed into pellets by pressure. Substitution of fuel oil in varying amounts in the binders enhanced the mixing and penetrating qualities of these binders but at the same tire tended to make the pellets more porous. Tall oils performed the same function to a lesser degree and usually decreased the water absorbency of the finished pellets. Heat-treating temperatures to set up these binders were moderate -about 5000 F. for 30 to 50 minutes was usually enough for both drying and heat treating. Nodules made with 1-1/2 to 2 percent of bentonite as a binder were easily mixed and formed. They required a high degree of heat (about 1,500° F.) to develop their strength and were quite water-absorbent when finished. Two fluorspars were examined for weight and fluorite loss after heat treatment at similar temperatures. Both showed a definite wej.ght and analytical loss of fluorite. Bentonite was used also as a binder to successfully nodulize finely ground oxides of iron, manganese, and nickel.

Jan 1, 1951

By David K. Denton

Results of the mineral resource study of the Upper Priest Lake RARE II study area indicate a low potential for the discovery and economic recovery of silver and lead in the Prichard Formation near contacts with the Kaniksu Batholith in the vicinity of the Mountain Chief Mine (fig. 1). Silver and lead minerals locally occur disseminated and in irregular quartz fissure-fillings in the Prichard Formation. Between 18^6 and 1967, 105 lode raining claims were located in the study area. The area was designated for "further planning" in the Final Environmental statement but was later changed to "nonwilderness" by President Carter after work was scheduled for the area.

Jan 1, 1981

By Yumi Nakashima, Setsuo Maeda

Vibration magnitude and frequency of the z-axis vehicle seat are time-variant, which are influenced by not only vehicle vibration characteristics themselves but also road surfaces, speeds and the human body. There is little in the current reporting about evaluating and analyzing automobile seat vibration that focuses on the time-variant. Yaguchi et al.1 has proposed a method to evaluate automobile seat vibration that is based on judgments using a subjective mental state. Their method focuses on the time-variant magnitude of the peak frequency on a power spectrum density. However, their method has no consideration of all the frequency contents of the discomfort, nor comparison between different peak frequency vibrations. Suzuki2 has emphasized that the vehicle vibration should be judged by a series of vibration stimuli to evaluate, because the vehicle vibration is time-variant, which isn’t a matter of the relationship between a single vibration stimulus and a subjective response. He clarified that the human sensation to the vehicle vibration discomfort changes every moment showing the relationship between the frequency-weighted r.m.s. acceleration calculated every 5 seconds and the category judgment to vehicle vibration discomfort every 5 seconds. However, his study doesn’t show what parameter connects to the subjective final judgment to vehicle vibration. Therefore, we applied the method similar to ISO100563 considering the time-variant to the vehicle seat z-axis vibration evaluation. The new method for the vehicle seat vibration considering the time-variant was examined on the hypothesis that the final subjective evaluation must be conducted from the judgment summarizing a series of vibration stimuli. Methods The vibration bench system, which reproduces the movement of a vehicle floor, was used for the experiment with the single-axis (vertical direction) four-post road simulator system, which is usually used for a car, as shown in Fig.1. The experiment was done on the right side of the vibration bench using the floor vibration which was 5.5 minutes, 0.822 m/sec2 (Wk) over the range 0.5-20Hz with 4 male subjects (age ave21.5, SD0.5, weight ave75kg, SD7.91kg, height ave166.8cm, SD5.2cm) and 4 suspension seats. As Fig.2 shows, subjects evaluated the degree of discomfort every 5 seconds to each seat vibration measuring the seat z-axis vibration acceleration. [ ]

Jan 6, 2006

By Carl W. Kelley

PRODUCTION in the United States of carbon black has increased from 20 million pounds per year in 1920 to over 2 billion pounds in 1964 valued at $156 million, mostly for consumption by the rubber-tire industry, which uses over 90 percent of total production. Production of over 2 billion pounds in 1964 is a 7.8-percent increase over 1963 and is the first time furnace black production has topped 2 billion pounds. Although 1964 channel black production dropped 6 percent below 1963, carbon black produced by the furnace process, which ac-counted for 92 percent of total production, increased 9 percent to 2,053 million pounds. Total shipments during 1964 amounted to 2,245 mil-lion pounds, a 7 percent increase. This growth parallels the expansion of the automotive and petroleum industries. Along with this expansion have been many advances, both in methods of manufacture and in the quality and variety of blacks available to industry. There are several kinds of carbon black, thermal, channel, furnace, lamp, and oil blacks. Until recently, channel has been the important black in rubber compounding. Following the introduction of the synthetic GR-S, and more recently of "cold rubber," it has been found that certain furnace blacks with particle size larger than that of the standard channel black give superior reinforcement. A great advantage of furnace black is that its yield per unit of gas feedstock is higher than that of channel black. The 184-million-pound increase in domestic carbon black sales was partially offset by a 37-million-pound decrease in exports. Decrease in exports especially to Europe, is expected to continue. In Europe, as in the United States, the major end use for carbon black is in the manufacture of automobile and truck tires. Although the number of automobiles in Europe is predicted to grow by about 7.5 percent per year, compounded until 1975, the increased demand will be met by a 20 percent increase in existing capacity and by the new plants being built in Europe by U.S. companies. Also) aromatic oils for producing furnace blacks are plentiful now that western Europe's chemical industry is switching to a petroleum base.

Jan 1, 1965

By Donald F. Reed

During the first 6 months of 1948 the Bureau of Mines investigated the titania, deposit on the Wynn 0. Christy property in northern Hot Spring County, Ark. The property is situated in Magnet Cove, about half a mile north of the Magnet Store and U. S. Highway 270 (fig. 1). The purpose of the investigation was to determine the extent and grade of the ore body and to obtain a representative sample of the ore in as nearly natural condition as possible for use in metallurgical testing. All of the titania that has been marketed from Arkansas mines has been in the form of rutile from a deposit about 2 miles west of the Christy property. The titania in the Christy property occurs principally as brookite, which, with fragments of novaculite, quartz, and limonite, is imbedded in red clay. It is difficult to recover a core of the material. Three types of drills - a diamond drill, a bucket drill, and a Baker cable-coring tool operated on a churn rig - were employed in an effort to procure proper samples in their natural state. The Baker tool was found to be the most efficient and to be capable of drilling to a depth of 150 feet, making 80 to 100 percent core recovery (fig. 8). Total footage drilled was 1,536.9 in 21 holes, of which 7 were diamond-drill holes, 13 were bucket drill holes, and one was drilled with the Baker tool. The ore body was found to be 900 feet long, 500 feet wide, and more than 141 feet deep and contained 5.8 percent TiO2 and 0.52 percent 1720. Most of the deeper drill holes bottomed in ore, and there is a possibility that the ore may persist to a depth of several hundred feet. The Metallurgical Division of the Bureau of Mines is conducting experimental work at the Mississippi Valley Experiment Station at Rolla, Mo., for the purpose of developing methods of concntrating and utilizing the ore.

Jan 1, 1949

By W. J. Huff, G. W. Jones, I. Spolan, R. E. Kennedy

"INTRODUCTION Information on the exploeibility and ease of ignition of acetylene is important in connection with investigations by the Bureau of Mines and others seeking the causes of explosions in medium-pressure acetylene generators.A previous report 6/ gave preliminary results of an investigation made by this Bureau to determine the causes of these explosions. This report indicated the need of amending Federal specifications for ""1/4 by 1/12"" carbide to reduce the amount of fine sizes permitted under the specifications then in force. Tests described in the above report showed that certain sizes of carbide may, under certain conditions, attain excessively high temperatures when acetylene-water vapor mixtures are passed through carbides for extended periods.Federal specifications P-0-101, Amendment 5, June 28, 1944, are now in effect. These latest specifications permit a maximum of 7 percent of ""1/4 by 1/12"" carbide by weight to pass through a 0.0661-inch sieve and a maximum of 2 percent to pass through a 0.0555-inch sieve. Experience has shown that these specifications have insured a safer size range of carbide for medium-pressure acetylene generators.Although the improvement in the size range of the carbides has aided in the prevention of explosions, there have been explosions in which the carbide used at the time of the explosion met the latest Federal specifications."

Sep 1, 1945

By Khamis Y. Haramy

This U.S. Bureau of Mines report describes the use of Bureau-developed flat and cylindrical hydraulic borehole pressure cells. A brief description of the fabrication, installation, and pressurizing equipment is given and pressurizing procedures are discussed. Theories available on evaluation of data from the flat and cylindrical pressure cells and examples of data analysis and stress evaluation are also presented.

Jan 1, 1991

By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different field and regions as made by the Bureau of Mines Hempel method of analysis.4/ Several of these reports include analyses off crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different fields and regions as made by the Bureau of Mines Hempel method of analysis.4 Several of these reports include analyses of crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By Douglas Ketcham, Thomas Jetzer

While the neurological and vascular aspects of Hand-Arm Vibration Syndrome (HAVS) has been generally accepted as a medical condition, the medical criteria and the clinical findings used to establish the diagnosis has been more difficult to bring to consensus. The criteria was first quantified by the Taylor-Palmear scale.1 This criteria was subsequently modified in 1986 at the 1st Stockholm Workshop2,3 to included more acceptance for the neurological effects that characterized the predominate findings in some workers. The relationship between hand-arm vibration and Carpal Tunnel Syndrome was defined in NIOSH 97-1414. While the aforementioned documents have defined the clinical entities associated with hand-arm vibration exposure, agreement on the clinical findings and test to confirm the diagnosis has be been more difficult to bring to consensus. Clinicians assessing HAVS has relied on a number of varied neurological and vascular tests. The neurological testing has focused on assessing damage to the sensory capability of the fingers for the neurological component including tests to measuring ability to sense vibration, cold or other end point finger sensor functions. However, the vascular testing has been traditionally focused on the ability to either measure vascular function or to reproduce the vascular blanching that occurs in HAVS with cold water provocation. Recent assessment of this testing in the United Kingdom Coal Miner’s study has questioned the value of this testing especially in reviews by McGeoch.5 In an attempt to provide some type of definitive testing to substantiate vascular damage from hand-arm vibration exposure, angiography is an alternative or adjunct to cold water provocation testing. The standards that have been established to predict the level, type and incidence of HAVS have been based on clinical studies and reports that have essentially been all male populations. However, the recent entry of women into more vibration intensive jobs has brought about the exposure of some women to high levels of vibration previously only previously experienced by men. However, there have been only few studies that look at HAVS in women6. Although exposed the same vibration levels, it has not been clear that the latency and type of pathology of HAVS in women will be the same as for men. The purpose of this study is to look at recent case studies of men and women exposed to jobs with high levels of hand-arm vibration with extensive clinical testing for both the neurological and vascular components of HAVS as well as other associated upper extremity conditions such as Carpal Tunnel Syndrome.

Jan 6, 2006

By Donald O. Capstick

In 1481, U.S. Bureau of Mines personnel conducted a survey of mines, prospects, and mineral resources in the Table Mountain RARE II area. There are no mines or active prospects in the study area. One prospect in the study area, the Waterfall Prospect, is estimated to contain 480 tons (440 t) of indicated subeconomic tungsten resources averaging about 0.18 percent tungsten trioxide (W03). Other tungsten occurrences are at the Stevens Prospect, just northwest of the area. Stone and sand and gravel deposits in the area are not considered to be resources because equal or better quality material is available closer to major markets. INTRODUCTION The 4,400-acre Table Mountain study area is 13 mi (21 km) southwest of Bishop, California, on the eastern flank of the Sierra Nevada range. The John Muir wilderness adjoins the study area on the southwest (fig. 1).

Jan 1, 1982

By H. Nelisse, S. K. Patra, A. Natani, S. Rakheja

The current laboratory methods for assessing the vibration attenuation performance of seats involve repetitive trials with a number of human occupants, and raise certain ethical concerns. Moreover, the measurements with human subjects yield considerable variability in the data. Alternatively, several anthropodynamic manikins have been developed for effective assessments of the coupled seat occupant system [1]. The effectiveness of a manikin in predicting the response of a coupled seat-occupant system lies in its ability to reproduce the biodynamic response of the seated human body in terms of force-motion relationship at the body-seat interface, such as apparent mass (APMS). A number of prototype manikins have thus been developed on the basis of biodynamic characteristics of vertical vibration-exposed seated occupants of different body masses in the vicinity of 5th, 50th and 95th percentile male population. This study concerns with the analysis of a passive prototype manikin to enhance its ability to reproduce the idealized APMS response characteristics of the vibration-exposed seated human subjects defined in ISO-5982[2] for mean body masses of 55, 75 and 98 kg. Methods The APMS responses of a prototype anthropodynamic passive manikin were thoroughly characterized in the laboratory under different excitations and body mass configurations. The manikin was designed with sufficient flexibility to configure mechanical-equivalent models corresponding to seated body masses of 55, 75 and 98 kg, by adding/removing specified masses and springs (Fig. 1). The manikin, configured for a specific body mass, was positioned on a rigid seat without a backrest, which was fixed to the force platform of a whole-body vertical vibration simulator. The simulator was programmed to synthesize random vertical vibration with flat acceleration power spectrum in the 0.4-20 Hz frequency range with two different magnitudes: 1 and 2 m/s2 overall rms acceleration. The total static and dynamic forces of the manikin to and the seat were measured using the force platform, while a single axis accelerometer was installed on the seat pan to measure acceleration due to vertical excitation. The measured data was appropriately corrected for the rigid seat inertia force, and the apparent mass [ ]

Jan 6, 2006

By Franklin B. W. Woodbury

The Bureau of Mines, as part of its goal of helping maintain an adequate supply of minerals to meet national economic and strategic A needs, is evaluating alternative technologies to treat oxidized taconites. Since process control is an essential element in the application of these process technologies, research was performed on a prototype monitoring system utilizing a Californium-252 (252-Cf) neutron source and a thermal neutron capture-gamma ray spectra analysis method to measure the amount of iron and percent solids in process slurries. The prototype system was used to monitor the concentrate and tailing streams in a 900-lb/hr flotation pilot plant during continuous around-the-clock tests. The iron content of the process slurries was determined by measuring the total peak areas under the capture spectrum peaks at 7.626-7.632 MeV, the associated escape peaks at 7.136-7.122 and 6.626-6.612 MeV, and the iron doublets at 4.900 and 4.998 MeV. A potential method for determining the percent solids in process slurries using the 2.22 MeV hydrogen capture peak is discussed. Results of this work demonstrate a potential method for providing process control parameters using the data from thermal neutron capture-gamma ray reactions.

Jan 1, 1980