Search Documents

By Aleksandar D. Bugarski, Robert J. Timko

Despite extensive research efforts conducted in the past decades, occupational health risks associated with exposure to nano and ultrafine aerosols emitted by diesel power equipment are still not completely understood. The complexity of physical and chemical properties of diesel aerosols, constantly changing with the implementation of advanced diesel emissions control technologies, make this task rather challenging. The objective of this paper is to identify and characterize nanometer and ultrafine aerosols emitted by diesel engines in the underground environment and evaluate the effects of selected contemporary control technologies on physical properties, chemical composition, and in-vitro toxicology of diesel aerosols. The physical and chemical properties of the nanometer and ultrafine diesel aerosols are to be characterized through a test series in the NIOSH Lake Lynn Laboratory experimental mine. The crucial part of the study has been development of a facility that allows researchers to generate field results with precision and accuracy characteristics of a laboratory environment. The knowledge obtained from this study should strengthen our understanding of the health implications related to exposure to diesel particulate matter and aid in assessing the potential of various control technologies for reducing this exposure.

By Frank L. Wideman

"INTRODUCTION The Cphir Hill Consolidated mine was examined 2/ in January 1944. It was recommended that the mine be explored for the purpose of increasing of lead and zinc ore.The Bureau of Mines began exploratory work at the mine in June 1944 and completed it in June 1945. The work was planned to indicate ore that could be developed and extracted quickly and consisted of core drilling and trenching.ACKNOWLEDGMENTSIn its program of exploration mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. Its the policy of the Bureau to publish the facts developed by cash exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, O. C. Ralston, chief, analyzes samples and performs beneficiation tests.The work reported on in this paper was conducted under the supervision of S. R. Zinmerly, removal engineer of the Western Region, and J. A. Marsh, district engineer of the Utah-Wyoming district. Subsequent to May 1945, the project was under the supervision of Paul T. Allman, chief, Salt Lake City Division, Mining Branch. The management and employees of the Ophir Development Co. wore very cooperative. Credit is due to the Bureau employees, all local men, for the excellent amount of work accomplished."

Jun 1, 1947

By Kihong Park

A hygroscopicity tandem differential mobility analyzer (HTDMA) technique is used to determine size-effect of nanoparticles (NaCl, (NH4)2 SO4, KCl, NH4NO3, MgCl2,CaCl2) on their hygro­scopic properties (deliquescence relative humidity (DRH) and hygroscopic growth factor (GF)). The HTDMA system uses a combination of two nano DMAs and two regular DMAs to measure particle size change in a wide dynamic particle size range. Particles are subsequently analyzed with a transmission electron microscopy to investigate the potential effect of particle structure or morphology on the hygroscopic properties. We found that structural properties of NaCl and (NH4)2SO4 particles also play an important role in determination of the DRH and GF and are more pronounced at smaller diameters. Data show that the DRH of NaCl nanoparticles increased from *75% up to *83% RH at 8 nm and that their GF decreased with decreasing size. The extent to which the GF of NaCl nanoparticles decreased with decreasing size was greater than theoretically predicted with the Kelvin correction. The GF of furnace-generated NaCl nano­particles that have pores and aggregate shape was found to be smaller than that of atomizer-generated particles that are close to perfectly cubic. For the case of atomizer-generated (NH4)2SO4 nanoparticles, we observed no signi?cant size-effect on their DRH, and the measured GF agreed well with predicted values using the Kelvin correction. For furnace-generated (NH4)2SO4 nanoparticles, a gradual growth at moder­ate RH without noticeable deliquescence behavior occurred. Their TEM images showed that contrary to atomizer-generated (NH4)2SO4 nanoparticles the fur­nace-generated (NH4)2SO4 nanoparticles are not perfectly spherical and are often aggregates having pores and holes, which may favor holding residual water even in the dried condition. For atomizer-generated KCl, MgCl2, and CaCl2 nanoparticles, we observed no signi?cant size-effects on their DRH and GF for the mobility size as small as 20 nm.

Jan 1, 2008

By J. R. Thoenen

During the year 1927 the Bureau of Mines, at the request of a number of quarry operators, undertook to make a study of quarry operating costs in order to determine average costs for certain operating conditions and to suggest a model cost accounting system for quarry operations. A detailed questionnaire was prepared and mailed by the bureau to all quarries on its records as employing ten or more men in 1926.

Jan 1, 1929

By C. M. K. Boldt

Between 1989 and 1991, the greatest number of accidents in surface coal and metal/nonmetal mines involved haulage trucks. In 1995, the most frequently cited factor contributing to the 100 fatalities in these mines was powered haulage. In 1996, over 50% of the 84 Fatalities in mining that year were in surface mining. Because some of the world's largest mobile equipment is used in surface mines, and this equipment is involved in so many accidents and fatalities, new technologies are needed to alert truck drivers and people in spaces around the truck to the possibilities of collisions.

Jan 1, 1999

While coal occurs beneath about 18 percent of Utah, only 4 percent of the state has minable reserves. Utah's coal fields are mostly bituminous. Current coal production in Utah is largely by underground mining, making Utah unique among the coal-producing states. Most coal seams are more than 8 feet thick. Utah's coal resources are about 6.3 billion tons, 1.3 percent of the national reserve. Most of Utah's coal resources are held by the Federal Government and Indian tribes and are mined under lease. The climate of the Utah coal region is characterized by hot, dry summers and cold, relatively moist winters. Normal precipition varies from 6 inches in the lower valleys to more than 40 inches on some high plateaus. The growing season ranges from 5 months in some valleys to less than 3 months in mountainous regions. These extreme climatic conditions make reclamation difficult. Utah gained primacy when its regulatory program was conditionally approved January 21, 1981. Full program approval was obtained March 7, 1983. The Abandoned Mine Land Program was approved June 3,1983. A Federal Lands Cooperative Agreement was signed in March 1987; Utah performs all enforcement activities and some permitting activities on federal lands.

Jan 1, 1992

By R. V. Higgins, H. C. Miller

"INTRODUCTION The development of methods for determining the total quantity of crude oil that a given pool could be expected to produce in the future and the well-spacing and drilling programs most likely to result in the recovery of the maximum quantity of oil at the minimum cost became problems of acute concern to American oil producers and petroleum engineers during the second decade of the twentieth century, The United States faced what seemed at that time to be a serious shortage of petroleum, and it appeared that the constantly increasing demand for petroleum and its products could not be adequately supplied. Undrilled prospective acreage, which until then had been plentiful, seemed to be getting scarcer, competition was increasing, the margin of profit to the producer was shrinking, and the need for developing constructive policies of conservation appeared paramount. As a result of physical and economic changes then taking place within the petroleum industry prompted by the seemingly uncertain future, accurate knowledge pertaining to the probable future production of oil wells and of oil lands especially was needed and greatly desired. Furthermore, the need for obtaining the maximum quantity of oil from known fields caused technical information - which up to that time had not been deemed essential to the successful and profitable operation of oil lands - to be sought eagerly. The need for technical information, such as methods for determining future reserves of oil and the rate at which the oil could be obtained under a specific program of drilling, was emphasized further with the passage of the Revenue Act of 1918, and oil producers with enough income to place them in the taxable class were compelled, for the first time, to report their taxable income 4/ to the Treasury Department."

Nov 1, 1939

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 Don Conrad, Tom Friend, Bill Wiehagen, Lynn Rethi

On-the-job training (OJT) is a very common method of teaching job skills. Much of the training is done by experienced workers. This paper discusses small investments that can help improve the effectiveness of OJT. Effective OJT involves some structure and planning in the transfer of responsibility for task performance from the trainer to the novice. Assisting the OJT trainer could involve helping develop up-to-date job analyses and offering strategies for teaching and evaluating job skills. The scope of this paper addresses (1) organizational considerations supporting structured OJT, (2) general strategies for structuring OJT, (3) a typical approach for conducting OJT, (4) characteristics and duties of OJT trainers, and (5) limitations of OJT as a teaching method. Health, safety, and operational skills can be connected through training. Haul truck operator training is used to illustrate some of the concepts discussed in this paper.

Jan 1, 2002

By Jerry A. Wichser

A series of linear programmed instruction modules was developed in the general subject areas of Blasting Technology & Explosives Safety & Electrical Training. The linear programs (modules) were developed in the form of tape-slide plus workbook materials, while the branching format evolved from the LTS teaching machine system from MIT, through several other teaching machines and micro-computers, finally settling on Radio Shack TRS-80 microcomputers, Models I & III. Initial validation figures indicate that essentially the same result, are attained from both methods (based on pre and post test scores), with the most noticeable difference being an approximately 25% savings in study time with the branching modules. In December 1980, the development of modules on High-Voltage Training, Trolley Wireman Training, and Compressed Gas Safety was added to the overall tasks of the contract.

Jan 1, 1984

By Neil J. Mansfield

Tool manufacturers are required to provide declarations of vibration emission values in order to sell their tools within Europe. To ensure that users can compare results obtained from different manufacturers, the declared values must be obtained using a methodology as specified in the relevant test code (such as in the ISO 8662 series of standards). In most cases, the vibration emission values obtained using test codes under-estimate the vibration that an operator will be exposed to when using the tool on a work-site. A further problem with manufacturers’ data is that usually only a single value is provided for a tool. This is despite many factors affecting the vibration emission, including inserted tool type, work piece, operator technique, tool condition. New improved test codes are in the process of being developed. In order to provide guidance to users on how to interpret manufacturers’ data, a Draft CEN Technical Report (Draft CEN/TR 15350 (2005)) was developed. Part of the CEN/TR provides multiplication factors for combinations of task and tool type. For example, data obtained from electrical hammer drills (tested according to EN 60745-2-6:2003) should be multiplied by 2, for hammering applications, in order to obtain an estimate of the vibration emission during work. In response to concerns from industry, the UK trade association OPERC have, in collaboration with hire companies and tool manufacturers, established a freely accessible online database of tool emission values based on independent tests carried out under simulated work-site conditions. This paper reports some of the data obtained from electrical hammer drills, highlighting the range of emission values that can be obtained for a tool. Data from many other tool types are also included in the database. Methods Tri-axial hand-arm vibration was measured at both handles of each of 19 electrical hammer drills, in accordance with ISO 5349-1 (2001). Each tool was measured with three experienced operators and at least 5 runs were completed for each operator. Tools were tested using a range of appropriate new bits from 4 to 40 mm diameter. The minimum number of bits for a tool was 3; the maximum number was 29. 146 tool / bit combinations are reported here, representing about 2200 individual 6-axis measurements. Operators were required to drill vertically into a concrete block with a compressive strength after 28 days of 40 N/mm². Two drills (1 and 15) were battery powered; others were powered using a 110V transformer supply.

Jan 6, 2006

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

"DIGREGORIO, K. A., E. V. CILENTO, AND R. C. LANTZ. A kinetic model of superoxide production from single pulmonary alueolar macrophages. Am. J. Physiol. 256 (Cell Physiol. 25): C405-C412, 1989.-A kinetic model was developed to describe the production of superoxide (02) by single pulmonary alveolar macrophages (PAM). Model predictions were compared with experimental results obtained from single rat PAM. The 02 was quantified by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate (NBTH,) from video-recorded images of individual cells. The kinetic model considered three reactions: 1 ) the production of extracellular 02 from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, 2) the subsequent dismutation of 02 to form H,O,, and 3) the reaction of 02 and NBT to form diformazan. NBT specificity for 02 was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) that catalyzes the dismutation of 02 to H,O,. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations because NBT is a relatively small molecule (818 mo! wt) compared with SOD (34,000 mol wt). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/ or electrostatic effects, since SOD is also negatively charged, whereas NBT is positively charged.PULMONARY ALVEOLAR MACROPHAGES (PAM) protect the lungs by phagocytizing foreign debris and bacteria. This process is accompanied by the production of superoxide anion (02) at the surface of the plasma membrane (3, 31). Superoxide readily dismutates to form H20 2 and subsequently, other oxygen metabolites which have been shown to be both antibacterial and cytotoxic (21, 25, 35).Superoxide is produced from the reduction of extracellular O, at the surface of the cell membrane by NADPH oxidase by the following reaction (3, 4)"

Jan 1, 1989

By J. H. Hild

The Shanton magnetite-ilmenite deposits lie on the east flank of the Laramie Mountains, 43 miles northeast of Laramie, Albany County, Wyo. (fig. 1). The Shanton and other similar deposits in the Laramie Mountains were examined by Bureau of Mines engineers during 1942, 1943, and 1945, and a report2/ describing the results of a dip-needle survey and surface sampling was published in 1946. The Shanton deposits occur in a relatively flat section of the range at altitudes varying from 7,500 to 1,650 feet (fig. la). Prevailing rocks in the Shanton area consist of anorthosite with intrusive dikes of gabbro differentiates and granite. Titaniferous magnetite outcrops in five masses, which are separated at the surface by overburden and anorthosite.

Jan 1, 1953

In 2007, a total of 4,639 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Stone mines comprised 31.2% of all mining operations. ? Mines producing the primary commodity of limestone (crushed and broken) comprised the largest number of operations (n=2,051; 44.2%). ? Stone mining operations were located in all states and territories except Delaware and North Dakota. ? Pennsylvania had the most stone mines (n=373; 8.0%), followed by Texas (n=352; 7.6%).

Aug 1, 2009

By M. J. Ackerman

This study was undertaken to make a comparison between the cost of mining coal under roof bolt and under conventional timber methods of roof support. Studies were made at 14 mines in Pennsylvania, eastern Ohio, and northern and southern West Virginia. At each mine data were obtained for sections of the mine where the physical conditions, mining equipment, and mining systems were similar. Coal, recognized as one of the basic industrial fuels, is very competitive with other fuels, and management, in order to protect and enlarge its market, must be continually alert to find more efficient methods of production. Continuous production of coal is desired by all operators but never obtained. In mechanized mining the performance and production vary with operating time, which can be interrupted by many variable factors, such as condition of the roof, method of roof support, condition of equipment, water, ventilation, power, transportation, efficiency of operating crew, and supervision.

Jan 1, 1961

By Foster Fraas

The Bureau of Mines investigated a method for calculating values of adsorption energy; the goal was to devise an equation consistent with experimental data accumulated in the investigation of adsorption as related to ore separation processes. Numerical identification of the constants of a previously formulated equation provided an equation by which values of adsorption energy could be calculated. Values thus calculated checked with those obtained by calorimetric measurement.

Jan 1, 1965

By David Garry, Michael J. Brnich, Lynn L. Rethi, Henry P. Cole, William J. Wiehagen, Roberta A. Calhoun

This document contains most of the materials needed to use the exercise. The main part of the document is the instructor's copy. It tells how to use the exercise, presents the objectives, the master answer sheet, the scoring key, and discussion notes to be used following the exercise. The next section summarizes results from field tests of the exercise, and reports the miners' evaluation of the activity. The last part of this document is three appendices. Appendix A is the exercise problem booklet. This booklet can be duplicated locally. The booklets are reusable. One is needed for every person in the classroom. Appendix B is the answer sheet and the trainee's questionnaire. Copies of this answer sheet must have the latent image (invisible) ink answers that appear in Appendix C printed on them.1 Answer sheets are consumable. One is needed for each person or each small group of persons who work the exercise. Exercise Summary Read this section first. It determines if the exercise is appropriate for your classes. If you choose to use the exercise, examine the table of contents and review the remainder of this document. Type: Latent image Audience: Supervisors, Safety Personnel and Accident Investigators Length: Eight questions (30 minutes for administration plus 30 for discussion) Skills: Developing a strategy or plan to prevent slips and falls Following correct procedures in conducting an accident investigation Preventing unsafe work practices Recognizing and instituting hazard controls in the section Identifying and implementing safe work procedures Location: Underground coal mine section Problem: You have been the general mine foreman at White Rock Mine for 4 years and have worked at this mine for 12 years. The mine superintendent calls you into his office. He gives you an accident report of an employee in 4-G section who was injured while carrying rock dust bags from the rock dust car to a battery powered scoop. It is several days after the accident and the mine superintendent assigns you and the safety supervisor to thoroughly investigate the accident to determine all the contributing factors. Your job is to make specific recommendations to prevent future slipping/tripping accidents.

Jan 10, 1999

By James C. Fowler

The design and field testing of a seismic miner detection and location system arc described. This work was carried out over a period of three years. The first two and one-half years were sponsored by Continental Oil Company, while the last period of tests were done as the first part of a one-year contract with the U.S. Bureau of Mines. Laboratory and field experimentation in three different nines under simulated emergency conditions have led to three important results: (1) Taps on roof bolts with normally available objects can usually be detected up to horizontal distances of 1,000 ft. (2) The origin of the tans can be located by on-site processing with a small computer. (3) Some predetermination of the approximate location is necessary for a quick and successful rescue. This report also includes preliminary specifications an,d cost guidelines for construction of a transportable field system capable of matching the performance characteristics of the one used during the field tests.

Jan 1, 1973

By E. R. Palowitch

Coal wasted with mine refuse represents losses in overall recovery of merchantable coal to the mine operator and a concomitant reduction in domestic reserves of available coal. Fraser, Kelley, and Graham3/ in studying the available coal in mine refuse in the Pittsburgh district of western Pennsylvania have estimated that at least 1 ton of mine refuse is produced for each 10 tons of merchantable coal and that 20 percent of this mine refuse might be recovered as salable coal by mechanical cleaning. SUMMARY This investigation dealt with the mechanical recovery of coal from wine refuse by a dense-medium washery employing pulverized mine rock as the dense medium and operating at a rate of 175 tons per hour. Two types of mint refuse were tested: Freshly mined and that .which had been mined 2 years before and piled on a waste dump.

Jan 1, 1955