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By J. Ankrum, T. Xia1, D. Wilder, K. Spratt

The human lumbar spine is inherently an unstable structure and requires sophisticated neuromuscular control to maintain its stability and for performing physical tasks. As a consequence, it is important to understand the potential health effects on human operators of mechanical stimuli such as shock and vibration.1 Impact applied to a vehicle operator combines the risk of sudden, unexpected load with the mechanical stress of the seated posture.2 Because many work environments contain the potential for multiple, unexpected impacts, it is important to understand how the trunk muscles respond to complex conditions. We believe the results have implications for isolation design and standards development. Methods Muscle activity was recorded during simple and complex impacts, applied randomly and without warning, while subjects sat on an air-suspension truck seat located on a man-rated 6-DOF motion platform (Rexroth-Hydraudyne). Simple (single) impacts consisted of 100 ms quarter-sine jolts in the side-to-side (L and R) and vertical upward (V) directions with peak amplitude at 0.4 g. Complex impacts consisted of combinations of two simple (single) impacts in sequence (LV, RV, VL, VR), separated by 100 ms. Twelve right-handed males (23.7 ± 7.8 years old) were tested without a blindfold under 2 posture conditions (supported while leaning back and unsupported, sitting upright) and 2 seat suspension conditions (present or absent). Each type of impact was repeated three times under each posture and suspension condition, resulting in 84 impacts in total. Surface EMG signals from the left and right erector spinae (ES), rectus abdominis (AR), external obliques (EO) and internal obliques (IO) were recorded and transformed to 25ms RMS values. The response time, defined as the time the muscle activity exceeded the mean + 2 STD of the pre-impact resting period, peak response amplitude, and time were then derived. A mixed-model repeated measures analysis of variance was used to evaluate statistical significance, where type I error rate was set at .05. Results One question we asked of these data was whether there were differences in responses related to simple single strike impacts (L, R, or V) and complex, double-strike impacts (LV, RV, VL, VR). There are 21 possible combinations of comparisons of simple and complex impacts to each other. The differences found are listed in Table 1.

Jan 6, 2006

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

This laboratory has developed a sensitive electro-optical method to quantify the initial rate (R) and total amount.(MAX) of superoxide (SO) produced by single pulmonary alveolar macrophages (PAM). The method uses a microscope to visualize PAM in culture, and to video record the images during the time the cells produce SO. MAX and R are calculated from measurement of temporal changes in optical density in the images due to precipitated diformazan formed by the reaction of SO, produced by each PAM, with nitroblue tetrazolium present in the culture medium. To date, values of Rand MAX, measured due to adherence of PAM to the dish, have been compared to values obtained when quartz, coal mine dust (CMD), and kaolin were added to the medium (in vitro). R and MAX have also been calculated for PAM lavaged from animals exposed to quartz and CMD in the WVU Inhalation Facility. Presently, experiments are being done using serum which permits PAM to be restimulated by different dusts to help establish a dose response effect, and a means to study the effects of lung surfactant on modifying the toxicity of inhaled dusts. Long term, this methodology should provide useful insight· into establishing the role SO plays in the phagocytosis of inhaled dusts and bacteria, in PAM dysfunction, and in lung diseases such as pneumoconioses. Supported by the Department of the Interior's Mineral Institute Program administered by the Bureau of Mines through the Generic Mineral Technology Center for Respirable Dust (G1135142).

Jan 1, 1988

By C. Travis Anderson

 The general conclusion of earlier investigators was that the action of sulfur dioxide on manganese oxides of Cuyuna ores was not sufficiently pre- ferential to be attractive as the basis for a commercial process. Bradley4/ and his coworkers discarded it for leaching with boiling ammonium sulfate solution, and Sweet5/ used a baking operation to render the iron insoluble. These results were confirmed by the early tests in the present investigation, which were made on brown ores (Sagamore), using acid additions, because at that time the Technologic Committee on Manganese held the opinion that these ores constituted the major available reserve in the Cuyuna district. However, when it appeared that the black ores, or the formation in which they occur, were a possible source of a large tonnage of manganese, the use of sulfur dioxide and sulfuric acid leaching was again reviewed, and a satis- factorily preferential action on the manganese was found. It was originally thought that the use of sulfuric acid ahead of, or at least with, the sulfur dioxide simplified the process, particularly by preventing formation of dithionates. Removal of the phosphorus from the solution by neutralization with lime or fresh ore was suggested. The tests recorded in this report indicate that it is not practicable to use enough acid to prevent formation of dithionate and that the value of excess sulfuric acid is doubtful, particularly in regard to satisfactory manganese:phosphorus and manganese:iron ratios.

Jul 1, 1942

By Gerrit V. R. Goodman

Supplemental water sprays were placed along the sides of a continuous mining machine to improve suppression and confinement of the dust cloud under the cutting boom to re- duce downwind dust levels. Using a full-scale mock up of a continuous mining machine, preliminary work showed that these side sprays improved suppression of the dust cloud and redistributed this cloud under the cutting head. This led to reductions in dust levels around the machine and in down- wind airways for some positions of the mining machine. This testing also showed that side spray effectiveness was influenced by the distance from the fresh air ventilation device to the cutting surface, termed the ventilation setback distance. These sprays produced larger reductions in machine and re- turn dust levels at smaller setback distances than at larger setback distances. These side sprays then were installed in similar locations on a mining machine at an underground coal mine operation to evaluate their effectiveness for im- proving suppression and capture of dust by the flooded-bed dust scrubber. Although sampling could not be conducted successfully in the return, sampling around the mining ma- chine and at the machine operator showed that dust levels decreased with use of these sprays. Further analysis showed that these sprays were most effective at the smaller setback distances, a result confirmed by full-scale laboratory testing. Keywords Occupational Health, Dust Sampling, Coal Mining. Continuous Mining, Control Technology

By J. A. Zimrner, R. J. Tirnko

The roles of main mine fans in underground mines are to induce airflow and continuously re- move hazardous gases and dust. While most larger mines use multiple fans to accomplish these tasks, many smaller mines employ only a single fan. This paper concentrates on those mines having only one fan to provide ventilation needs. If this fan should cease to function, it is likely that methane concentrations will in- crease in some areas of the mine. As a safety precaution, Federal Regulations require that personnel must be- gin evacuating the mine within fifteen minutes after fan stoppage. Powered haulage can be used to transport workers to the mine portal as long as travel is through areas where hazardous levels of methane are not expected. To determine where methane will accumulate along haulageways during a fan stoppage, air samples must be taken at specific areas and analyzed for hazardous gases. During this study, procedures were developed for measuring methane levels along the haulegeways that are used to exit a mine following stoppage of the main mine fan. Methane levels were measured in four different mines at selected underground locations during four planned fan stoppages. In these mines the measurements taken only at the specified locations showed that, if workers had used electrically powered haulage to exit the mine following a fan stoppage, the methane accumulated along haulageways during fan stoppages would not have significantly increased the risk of an ignition.

By C. W. Owings, F. E. Cash

"Transportation of explosives in mines is extremely hazardous, and where electric haulage is employed the danger is intensified. Insulated mine-car couplings have been adopted by at least five companies in Alabama and Pennsylvania - and undoubtedly in other States - to prevent an electric current passing from a mine locomotive to a car or between care joined by this coupling. The need for such protection is recognized in the report of an explosion.""Four hundred kegs of black blasting powder had been loaded into four mine cars at the railroad, to be hauled to the magazine, upgrade, by a trolley locomotive. On starting, the motorman put sand on the rail and a grounded circuit passed through the hitchings and so exploded the powder. No insulation was used between the locomotive and cars."" When used on man trips the insulated coupling further serves the purpose of guarding the men against shock. Four couplings are described so that a clearer understanding may be obtained of the details of construction.ConstructionThe general principles of construction are similar in all insulated couplings. The piece containing the hole for the coupling pin is made of steel and the steel parts are separated by an insulating material, such as fiber or wood. The coupling is either rigid or semirigid to prevent the bumpers of the mine cars from coming in contact and to keep the cars insulated from one another at all times."

Apr 1, 1928

By A. B. Cecala

A cooperative research effort was established between the Tilden Mining Company LC, the United Steelworkers of America, and the National Institute for Occupational Safety and Health to lower respirable dust levels in an iron ore grinding and concentrator plant. This cooperative effort involved three field studies to evaluate different techniques to lower respirable dust levels. The greatest impact on lowering respirable dust concentrations throughout this facility was achieved through ventilation changes. The most significant improvement was realized by changing the ventilation profile throughout the entire facility. The ventilation to this grinding and concentrator facility was provided by approximately 40 roof fans operating in either the intake or exhaust mode. The operation of these fans was significantly changed in an attempt to pro-vide more of a directional flow pattern throughout the facility, as well as to more closely balance the intake and exhaust air volume. This change accounted for a 31 pct reduction in respirable dust levels in the primary grinding area of the mill. Another successful modification was to improve the sealing of a reclaim tunnel to the outside and by barricading the access point from the reclaim tunnel to the concentrator plant. This minimized the dust liberated in the conveyor tunnels from traveling through the reclaim tunnel and into the plant. These two modifications illustrate the impact that improvements in ventilation can have on lowering respirable dust concentrations in iron ore processing facilities.

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

Le Système International d'Unités (SI) Equivalents of Common United States Units Length 1 ft (foot) = 0.30480 m Mass 1 lbm (pound mass) = 0.45359 kg Force 1 lb (pound) = 4.4482 N Volume Flow Rate 1 cfm = 0.00047195 m3/s Mass Flow Rate 1 lbm/min = 0.00756 kg/s Pressure (wg at 20° C) 1 inch wg (water gage) = 248.36 N/m2 1 inch wg = 248.36 Pa Power 1 hp (horsepower) = 0.74570 kW Energy 1 ft-lb = 1.3558 J Torque 1 lb-inch = 0.11298 N-m

Jan 1, 1977

By Dhaval Patel, Kim Witte, Charles Vaught, Michael T. Stephenson, Steve Booth-Butterfield, Cynthia Zuckerman, Brian L. Quick

This longitudinal field study was designed to encourage Appalachian coal miners in West Virginia and Pennsylvania to engage in hearing-protection behaviors. Method: Participants were mailed postcards that featured either a positive, negative, or neutral message on the outside of the postcard and a message encouraging hearing protection behaviors on the inside. The first posttest measurement of the effectiveness of the persuasive messages was conducted about a week after the postcards were mailed. The delayed posttest measurement was conducted six weeks later. Results: Responses from 307 coal miners revealed that the positive or neutral messages generated significantly more self-reported hearing protection behaviors than the negative message. Identical results were obtained in a delayed posttest assessment of miners' self-reported hearing protection behaviors. The positive message was also more effective than either the neutral or negative message in preventing defensive mechanisms from emerging over time. Impact on Industry: Positive and neutral messages were convincingly more than negative messages in facilitating self-reported hearing protection behaviors among coal miners. Similarly, the positive messages kept defensive processes at bay. Keywords: Hearing protection; Hearing loss; Coal miners; Campaign; Messages

By Isaac A. Zlochower

A number of ignition incidents involving mining and farm equipment have illustrated the surprising danger of drilling, cutting, or otherwise penetrating sealed compartments or frames that are filled with metal scrap for ballast. The presence of chemically-reactive metals (or electrochemically-active pairs), such as zinc in galvanized steel, can produce hydrogen from moisture in the steel scrap, and the resulting pressure, due to the internally-generated hydrogen, can produce an easily-ignited gas jet when the sealed component is penetrated.

By Andrew B. Cecala

While various types of equipment are used in bulk material processing plants to control respirable dust, the equipment often doesn't adequately protect workers. One cost-effective way to supplement your existing dust control equipment is to install a whole-plant ventilation system. This article outlines research by the National Institute of Occupational Safety and Health (NIOSH) on using whole-plant ventilation in two mineral processing operations to reduce respirable dust levels. Information also covers how to design a ventilation system for any bulk material processing plant.

By Hans M. Cassel

The specific objective of research presented in this report was clarifi- cation of physicochemical fundamentals of the mechanism of dust explosions. The equipment, techniques (chiefly photographic), and dusts (chiefly graphite and light metals) employed are described. From behavior of individual par- ticles, conclusions are drawn as to their cooperative function in ignition and combustion of dust clouds. Results are interpreted using thermal theory as accepted for combustible gas mixtures. Radiative transfer across the flame front, as a characteristic of dust flames, is given particular atten- tion. Related studies by other investigators are discussed.

Jan 1, 1964

By I. AITKENS

Tourmalines are among the most beautiful of all the semiprecious stones, and are unsurpassed even by corundum in variety of hue. The stones most suited to jewelry purposes are those comparatively free from iron. One reason for the fact that the tourmaline has advanced rapidly in public favor in this country is that it is found in California in great profusion and of extraordinary quality. The superb green and especially the pink crystals found at Pala and Mesa Grande in San Diego County, Calif., are deemed superior to tourmalines from all other localities.

Nov 1, 1931

By John N. Murphy

In fiscal 1996, the US Congress directed that the US Bureau of Mines (USBM) be closed. Certain functions were reassigned to other agencies. The remaining employees were separated and the unoccupied sites were decommissioned. As a result, 12 locations were closed and about 1,200 employees were terminated in March 1996. About 600 employees at five locations were reassigned to other federal agencies. This article provides a summary of the continuing functions, the agencies involved and the points of contact for each continuing function. The functions that were discontinued are also identified.

By John W. Buch

"INTRODUCTION The Ruhr coal basin is estimated to cover an area of more than 1,000 square miles. Here, the total thickness of the coal bearing formation (Carboniferous) is 10,500 feet, and drilling-hole have revealed 92 coal beds with a total thickness of 262 feet. 6/ Beds pitch from 0 to 90 degrees and about 70 percent of the wartime production came from beds that pitched less than 30 decrees. 5/For example at the Minisiter Stein mine, there are 24 minable coal beds ranging from 80 centimeters. (2 ft., 7 1/2 in.) to 250 centimeters (8 2 1/2 in.). The vertical thickness of the measures is 1,000 meters (3,200 ft.), and at this mine the deposits are covered with 150 meters (500 ft.) of surface wash. The cross section (fig, 1) at Fritz mine; Hoesch, A.G., Essen, Ruhr, is characteristic, The mines have been developed and worked to vertical depths of 2,000 to 2,500 feet by vertical shafts; main-level intervals are 500 to 700 feet apart. Haulage roads are straight, driven in rock, and centered as nearly as practical between property boundaries. Levels are sectionalized by driving crosscuts at right angles to the main haulage road on 800- to 900-foot centers. The roads are the main transportation arteries for the use of trolley or Diesel locomotives. A plan of the sixth main level (fig. 2) at the Bruchstrasse mine; Gelsenkirchener A.G., Bochum, illustrates main-level development and,sectionalizing with crosscuts. The cross section in figure 3 is that of the fourth crosscut west at the same mine."

Oct 1, 1946

The notion of wayfinding, as conceptualized by planners, geographers, and psychologists, denotes the ability of an individual to move from one point to another through physical space. In order to achieve this movement, a person relies on a cognitive map of spatial representations [Passini 1984]. Which features of this cognitive mapping will be stressed depend, in part, on the researcher's perspective. A planner, for instance, would tend to emphasize the effect of physical structures on mobility. A psychologist, on the other hand, might focus on individual differences in how human minds encompass and represent physical space [Evans et al. 1984]. There is yet another dimension to wayfinding that needs consideration, and it rests upon the idea that reality, as experienced by human beings, is mediated: "[People] have preselected and preinterpreted this world by a series of commonsense constructs ... which help them find their bearings in their natural and socio-cultural environment and to come to terms with it" [Schutz 1967]. These "common sense constructs" are arrived at socially and constitute the agreed-upon schemas that guide people's everyday activities. According to this principle, cognition is governed by some nonlogical factors that reflect not only individual procedures but collective ones as well. These group strategies, which are shaped by shared rules and values, influence "the information gathered, the ways it is processed, the inferences that are drawn, the options that are being considered, and those that are finally chosen" [Etzioni 1992]. From this perspective, cognitive maps, rather than being individual-centered templates of environmental images [Rovine and Weisman 1989] or representations of spatial relationships [Evans 1980], are partially group-centered schematic processes. As such, they are subject to reinterpretation, revision, and outside intervention [Kaplan and Kaplan 1982]. As intermediaries between the environment and behavior, cognitive maps serve as bases for decision-making. Traditionally, it has been assumed that good maps facilitate correct decisions, which in turn leads to optimal performance during wayfinding [Hunt 1984]. Given the argument that there is a social (non¬cognitive) facet to cognitive mapping, however, this image of a cognitive map as some sort of static reference construct that motivates individual action is too narrow and mechanistic. If cognition involves less a knowledge of the environ¬ment than it does the process of "giving it meaning through imposing an order on it" [Rapoport 1976], then wayfinding behavior is not j ust a function of setting and individual differences, but is also a function of one's "normative-affective" structure [Etzioni 1992]. Rapoport [1976] used such an assumption as the base for a set of hypotheses about the connection between "external demands" and "organismic factors." One significant assertion deriving from Rapoport's ideas is that environmental

Jan 1, 2000

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Haiti has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By M. Brnich, L. Mallett, C. Vaught, K. Kowalski

This paper discusses the data collected during an emergency evacuation training exercise at an underground mine in the United States. The focus of this paper is on the human reaction to smoke and the use of personal protective equipment. Specific issues related to the human stress response during an emergency will be discussed.

By Oleg Terichow

Electrophoretic mobility measurements were made on samples of Florida phosphate slimes to determine the optimum conditions of coagulation and precipitation in aluminum sulfate solutions. The addition of silica sand and other selected materials as mutual coagulants has demonstrated the practicability of coagulating two dissimilar particle systems by elimination of the repulsive double layers. By proper selection of the solution and its concentration, the reduction of the double layer to a zero point of charge causes coagulation and rapid precipitation of both particle systems. Confirmation was found in filtration tests and sedimentation tests.

Jan 1, 1973

By E. P. Youngman

Prior to 1854 the provincial legislatures in Austria enacted their own mining laws. The confusion that resulted from the existence of different codes when mining began to be conducted by modern methods forced the drafting of a law to cover all mining operations of the country. Such a general law (allegemines österreichisches Berggesetz) came into effect May 23, 1854, in the old monarchy, with the exception of Hungary, which had its own special laws. This general law of 1854 is still the basic mining law for Austria, although it has been amended and supplemented by a mumber of acts.

Nov 1, 1931