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"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and· approved February 25, 1913, made it the province, and duty of the Bureau of Mines to ""disseminate· information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1990, to December 31,1991. It, supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 and the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 from January 1, 1975, to December 31,1979,6 from January 1, 1980, to December 31, 1984,7 and from January 1, 1985, to December 31, 1989.8"

Jan 1, 1992

By A. O. Ipsen

As part of the Bureau's intensive investigation of domestic manganese deposits, lots of ore for testing were collected by Bureau engineers during examinations of several properties in Juab County, Utah. One low-grade and two intermediate-grade samples (13.5, 25.3 and 27.5 percent manganese) were procured by engineers of the Bureau of Mines from the 900--and 1,100-foot levels of' the Tintic Standard mine, situated 2 miles southeast of Eureka, Utah. The ore bodies were described as blocks of ore approximately 60 feet long, 40 feet wide, and 20 to 100 feet deep. The manganese-iron association in the Tintic Standard ores was intimate, and no significant concentration of the low-grade sample was made by ore dressing, However, both of' the higher-grade samples were readily beneficiated to marketable manganese products. Ore from the Oxen No. 5974 claim, 2 miles northeast of Eureka, Utah was low in grade (19.4 percent manganese) and was not amenable to the production of high-grade concentrates owing to the intimacy of association of the manganese minerals with silica. However, a fair manganese recovery was obtained in a product that, when sintered, assayed plus 40 percent manganese. The ore body is reported to be a replacement in limestone and is composed of manganese oxides intermixed with silica, decomposed rhyolite, and limestone. The Fields property consists of five mineral claims situated 3 miles north of Eureka, Utah. The deposit is a replacement in a contact between limestone and a quartz dike. Tests were made on representative samples of a 50-ton lot stored on the property. Although the mineral association in the ore (22.2 percent manganese) is not particularly complex, the physical properties of the manganese minerals render the ore refractory to ore-dressing beneficiation. As the ores varied widely in physical and chemical characteristics, samples from each property were considered as separate ore-dressing problems.

Jan 1, 1949

By A. H. Roberson, F. S. Wartman

For many years , it has been the common practice at most copper mines to recover copper in solution in effluent mine water by precipitating the copper with scrap iron.4/ The technique employed varies from simply throwing scrap iron or tin cans into the waste ditches to passing the water through elaborate launder systems containing detinned scrap and baled cans . In general , a considerable amount of low - cost copper has been recovered that otherwise would have been lost . Iron consumption usually varies from 1 to 1-1/2 pounds of iron for each pound of copper recovered . The grade of the precipitate may be as much as 90 percent copper.4/ ,5/ Where the consumption of iron is materially greater , its cost is likely to be the determining factor of profit . In times of emergency, when the demand for scrap iron for remelting increases the cost of the iron sharply, and the supply of tin cans is not large enough to meet requirements , recovery of the copper might not be economical . The three principal reactions that take place when an acid mine water containing iron and copper salts in solution is brought into contact with metallic iron are : (1 ) Copper is precipitated and an equivalent amount of iron is dissolved , CuSO4 + Fe Cu + FeSO4 ; ( 2) ferric salts are reduced to ferrous salts , Fe2 (SO4 ) 3 + Fe = 3FeSO4 ; and (3) the free acid in the solution reacts. with metallic iron to produce ferrous sulfate , H2SO4 + Fe = H2 + FeSO4 . = Because of the reported high.consumption of iron (5 to 6 pounds per pound of copper precipitated ), when copper in water from the Hornet mine of the Mountain Copper Co. ( California ) was precipitated upon scrap iron , a series of tests was made to determine . the . optimum treatment, time , and consumption of iron .

Feb 1, 1944

By Lincoln A. Stewart, P. S. Haury

"INTRODUCTION AND RESUME Arizona asbestos mines are the only sources on the American continents of iron-free chrysotile spinning fiber that meets the Navy specifications for asbestos fiber for use in covering electrical cables. Rhodesia normally supplies the bulk of this grade of asbestos at about half the Price of Ari zona spinning fiber. The acute submarine menace in 1942 focused attention on the danger that imports might be cut off and that a sudden demand for greatly expanded production might fall on the Arizona mines to supply the tonnage of this essential material needed for war production.A joint preliminary investigation of Arizona asbestos deposits was made in August 1941 by J. R. Thoenen, senior mining engineer of the Bureau of Mines and A. E. Granger, a geologist of the United States Geological Survey. A more extended investigation of the numerous asbestos mines and prospects, which are scattered over 25 townships of difficult terrain in Gila County, was begun by the senior author in August 1942.The Geological Survey assigned two geologists (Newton Chute and A. F. Shride) a few weeks later to study the geology as an aid in selecting the mines for the Bureau's exploration projects. Six mines were selected for exploratory work because it was desired to prove reserves of ore where production could be started quickly if urgent demand should arise. Acceleration of production is normally slow because of adverse operating conditions. First, the mines are at distances of 35 to 100 miles from Globe, the shipping and supply point, and the roads are few and poor. The mine openings start in steep canyon walls, so that mining supplies usually have to be packed in and the product packed out over 0.5 to 5 miles of burro trail. Second, most of the ore deposits are small, and the ratio of rock broken to spinning fiber recovered is very high, usually exceeding 200."

Aug 1, 1947

By Christopher Van Dyke, Knox Van Dyke, Lixin Wu, Jaime Gutierrez

"I. INTRODUCTION(SILICA, THE LUNG, INFLAMMATION, AND FIBROSIS)Inhalation of respirable-size silica (0. I to 5 µm in diameter) deposits the particles in the deep spaces of the Jung where oxygen is exchanged. The resulting pattern of inflammation is substantially different compared to that observed from other inhaled substances such as carbon, polystyrene titanium dioxide etc. 1 Following the inflammatory reaction the body attempts to isolate the damage by walling off the area via fibrosis. 2 The unique nature of the inflammatory response to silica makes it logical to infer that fibrosis is a later-stage manifestation of the initial inflammatory damage. In addition to the inflammation extensive lysis and cellular death particularly to macrophages and neutrophils, can occur, depending on the dose of silica.' The ingestion of significant amounts of silica by macrophages and neutrophils produces an inflammatory sequence which activates the lipoxygenase pathway of arachidonic acid metabolism and produces platelet activating factor (PAF) and leukotrienes (LT).4·5II. CALCIUM IONOPHORE MIMICS SILICA TOXICITY IN VITROPhagocytic cells exposed to silica in vitro produce PAF and LT. This response is reminiscent of phagocytic cells exposed to the calcium ionophore (A23 l 87) in the presence of ionic calcium.6-8 A23 l 87 forms a complex with free ionic calcium which passes through cellular membranes, thus transporting calcium inside the cell. The increased intracellular calcium concentration triggers the production of small amounts of prostaglandins large amounts of LT. PAF and. depending on dose cellular death (see Figure 1 ). Could silica cause LT production and cellular death by a similar mechanism? How could silica - an inert solid - act in a similar fashion as a soluble stimulant? Clearly the negative SiO2 and OH- surface of silica can bind calcium ions9 and therefore could theoretically act as a solid-state ionophore releasing bound calcium inside of cells following phagocytosis."

Jan 1, 1998

By Phillip Allender, Wolf Karo, Knox Van Dyke, Lixin Wu, Ali Ardekani, Jorge Garcia, Jaime Gutierrez

"We report that two different micropolystyrene round beads linked to either luminol or lucigenin have been developed. The 1-µ.m-diameter beads arc useful reagents that allow one to perform chemiluminescent (light producing) phagoeytic reactions without opsonization. It is known that luminol reacts with peroxidases (e.g., myeloperoxidase) while lucigenin reacts mainly with superoxide anion. Luminol and lucigenin beads produce cellular chemiluminescence (CL) with neutrophils, macrophages, monocytes, and differentiated human promyelocytic leukemic cells (HL60). When myeloperoxidase (MPO) is present luminol beads evoke higher CL from neutrophils, but when little or no MPO is present, lucigenin beads produce higher amounts of light. Lucigenin beads appear to be active inside these cells where unbound lucigenin does not enter freely.INTRODUCTIONA variety of cells, e.g., neutrophils (Ns) and macrophages (Ms), can engulf foreign particles (1). This engulfing or phagocytic activity is used by the body to kill bacteria and to eliminate foreign particles such as respirable dusts, e.g., coal, silica, or cotton. The neutrophil engulfs or phagocytizes bacteria which are coated with plasma antibodies and/or complement proteins (Fig. 1). The coating or opsonization allows the neutrophil to recognize foreign substances. Usually the absence of opsonization prevents the cell's recognition of a foreign particle and the particle is not phagocytized. Macrophages, particularly the alveolar Oung) cells, do not require opsonization for phagocytosis. Ms should not be selective toward individual dusts because they serve a major role in eliminating a variety of these.Particle size can also be a factor. Usually a particle with a diameter of 0.5-5 µ.m is considered in the respirable range. Larger particles are trapped before they reach the alveoli Oung spaces where oxygen exchange with blood occurs), ·and smaller particles do not generally settle, and are not engulfed by macrophages (2). Tabato and Ikada (3) found that maximal phagocytosis of microspheres takes place when their diameter is in the range of 1.0 to 2.0 µ.m. In addition, they found that beads with hydrophobic surfaces were more readily phagocytized than hydrophilic surfaces."

Jan 1, 1990

By Henry Kreisinger, John Blizard

This preliminary statement presents some of the results of tests carried out at the Lakeside Station of the Milwaukee Electric Railway and Light Co. , by the fuel section of the U. S. Bureau of Mines , in cooperation with the research department of the Combustion Engineering Corporation of New York . The object of these tests was to determine the thermal efficiency , ease of operation , and other particulars of a boiler equipped with specially designed furnace and burners for burning powdered coal . The boiler tested haş 13380 square feet of heating surface , and is one of eight boilers equipped with the Lopulco powdered coal system supplying steam to two 20,000 -Kw . steam turbines in the largest power house burning powdered coal . Twenty- six tests were run at rates of heat transference varying from 4000 to 8000 B.t.u. per square foot of boiler heating surface , and the mean thermal efficiency attained was about 84 per cent , based on the gross calorific value of the fuel as fired . The efficiency varied little with the rate of steaming , and its high value is accounted for by the small loss from incomplete combustion and the small amount of excess air which varied from 5 to 36 per cent . The coal burned had a gross calorific value of about 11500 to 12800 B.t.u. per pound , contained 2 to 5 per cent moisture , 33 to 36 per cent volatile matter and 9 to 13 per cent ash, and was so ground thaf 89 to 95 per cent would pass through a 100- mesh sieve . The ash had a softening point of 2150 to 2450 degrees F. , but did not fuse together at the bottom of the furnace because it was partly protected from the flame radiation by means of a series of water tubes connected to the boiler which were placed between the fumace bottom and the flame, ..

Jan 1, 1923

By G. E. McElroy, D. Harrington

In connection with the cooperative metal-mine dust and ventilation investigations of the U. S. Bureau of Mines and the U. S. Public Health Service , some underground data have been obtained with intent to ascertain the adaptability of the katathermometer for determining the comfort of working places in mines . This preliminary study indicates that the instrument will probably be useful for making routine determinations of comfort conditions in our mines , and that it may also prove an important accessory for investigative work on problems in ventilation and kindred subjects ; in both coal and metal mines , although the instrument should probably be altered somewhat for maximum utility under the varied conditions in the mines of the United States . The katathermometer is an instrument contrived by Dr. Leonard Hill , an eminent English physiologist , and its various features have been fully described by him in his book entitled " The Science of Ventilation and Open Air Treatment . " He made exhaustive experiments and concluded that the rate of cooling of the human body was the controlling factor in determining comfort or discomfort , and then set out to make an instrument that would measure this rate of cooling . The resulting instrument the katathermometer measures its own rate of cooling when its temperature approximates that of the human body and thus serves as an index of the rate of cooling of the body itself . - The instrument consists of an alcohol thermometer having a cylindrical bulb 1 inches long and 3/4 inches in diameter, and a stem about 8 inches long graduated from 95 to 100° F. This temperature range gives a mean temperature of 97.5° F. ( 36.5° C. ) , which is approximately that of the clothed body surface . The stem terminates in a small reservoir which serves the double purpose of acting as a safety overflow in case of overheating the bulb , and of insuring a regular rate of cooling by the time the meniscus has fallen to the 1000 point .

May 1, 1922

By Jr. Watts, J. L. Ambs, B. K. Cantrell, K. L. Rubow

"The University of Minnesota and the U.S. Bureau of Mines collaborated to develop and field test a personal diesel exhaust aerosol sampler (PDEAS). The PDEAS was field tested in five underground coal mines that use continuous miners and a variety of diesel vehicles, including diesel haulage and utility vehicles. One mine was surveyed a second time, with the haulage vehicles fitted with a low-temperature disposable diesel exhaust filter (DDEF). Aerosol samples were collected with a variety of instruments, including the PDEAS and the microorifice, uniform-deposit impactor (MOUDI). This paper presents the diesel exhaust aerosol (DEA) concentration data collected in these mines and assesses the impact of diesel face-haulage equipment, with and without exhaust filters, on underground mine air quality.The average DEA concentration at the haulageway location for five mines, determined by the PDEAS, was 0.89 mg/m3, with a standard deviation of 0.44 mg/m3 • DEA contributed 52 pct, of the respirable aerosol at the haulageway location. Use of the DDEF at one mine reduced DEA by 95 pct, with a standard deviation of 6 pct, and filter life averaged 10 h. DEA contributed a large proportion of the respirable aerosol concentrations in mines with diesel equipment, and a substantial reduction was achieved with use of a DDEF. INTRODUCTIONDiesel equipment is gaining popularity in underground coal mines. There are an estimated 1,951 units of diesel equipment in 152 underground coal mines compared with 1,100 units in 110 mines 5 years ago (J).5 This increased use is due to the recognition that diesel-powered vehicles are more versatile, which can contribute to increased productivity compared with their electrically powered counterparts. Approximately 33 pct of the diesel vehicles haul coal, 45 pct haul personnel and materials, and- 22 pct perform other duties, such as roof bolting, rock dusting, and road maintenance. Most mines using diesel equipment are located in Kentucky, Utah, Virginia, and Colorado."

Mar 1, 1992

By E. M. SEELEY, F. S. LOTT

The total capacity of the natural-gasoline industry to produce light hydrocarbon products increased to 21,322,000 gallons ( 507,670 barrels ) daily on January 1 , 1948 , from 17,928,000 gallons ( 426,860 barrels ) daily on January 1 , 1946. Expansion of the industry in the first two post -war years , 1946 end 1947 , thus averaged 9 percent annually , compared with 6 percent annually in the last two war years , 1944 and 1945 . The number of cycle plants increased only from 37 to 39 in the years 1946 and 1947 , and total capacity of these plants gained 21 percent to 5,857,000 gallons de ily on January 1 , 1948 , represent ing 27.5 percent of the total capacity of the industry , compared with 27.0 percent on January 1 , 1946. All other plants decreased in number in the two-year period from 589 to 510 on January 1 , 1948 , but their total daily capacity increased 18 percent to 15,465,000 gallons . The daily capacity of the average plant in the industry was enlarged from 28,600 gallons on January 1 , 1946 , to 38,800 gallons on January 1 , 1948 , continuing the long -established trend to producing units of greater size and efficiency . The average cycle plant capacity increased from 131,000 gallons daily to 150,200 gallons daily on the same dates as the average capacity of all other natural -gasoline plants increased from 22,200 gallons to 30,300 gallons . Owing to the elimination of small , obsolescent plants in Illinois , Oklahoma , and Pennsylvania , these States experienced the greatest reductions in numbers of plants in 1946 and 1947. In Oklahoma and Texas , several consolidations of two or more plants into a single operating unit were reported . Louisiana and Mississippi were the only States in which the number of plants increased , but daily capacity to produce light products was larger in eleven States on January 1 , 1948, than two years earlier . Added facilities in California and Texas accounted for 41 and 36 percent , respectively, of the national gain in capacity .

Sep 1, 1948

By R. L. Grayson, W. E. Wallace, M. D. Attfield, A. Q. Wearden, P. Bolsaitis, R. D. Kennedy, M. J. Keane, J. C. Harrison

"Respirable high-silica particles from four coal mines. a clay mine and a tunnelling site were analysed for silicon vs aluminum composition by performing scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDS) at electron accelerating voltages of 20 kiloelectron volts (keV). The same particles were analysed at 5 keV to determine possible differences in surface vs bulk composition. In some cases high-silica particles exhibited a decrease in the ratio of silicon to aluminium K-alpha line intensities with decreasing electron beam accelerating voltage. This behaviour is consistent with aluminosilicate surface contamination or occlusion of a silica particle. Some 20 high-silica particles were analysed from each of 10 samples. Powdered aluminosilicate glass was used as a control for the behaviour of silica with a homogeneous distribution of aluminium in the particle. Significant differences were found between the control and sample means for an Illinois bituminous coal mine dust, two western and one central Pennsylvania bituminous coal mine dust low-temperature ashes. and a clay mine and mill dust sample, but not for an anthracite coal mine dust and two central Pennsylvania bituminous coal mine dust low-temperature ashes. INTRODUCTIONRESPIRABLE dust quartz content commonly is measured on bulk samples by using i.r. spectroscopy or X-ray diffraction. For research purposes, individual particle-by particle SEM-EDS analysis at 20-30 keV electron beam accelerating potential may be used also. Such measurements have not provided an unambiguous association of quartz content with occupational pulmonary disease prevalence in exposed workers (WALTON et al., 1977). Rather, there is evidence that coal rank modifies the relationship between dust exposure and pneumoconiosis development (WAL TON et al., 1977; ROBOCK and BAUER, 1990; ATTFIELD and MORRING, in press). SEM-EDS analysis was performed to measure the silicon fraction, Si/(Si +Ai), at 20 and at 5 keV on high-silica particles to determine if some respirable quartz particles generated by mining exhibit heterogenous composition with depth (WALLACE et al., 1990), which might affect the bioavailability of the quartz surface."

Dec 1, 1995

By C. A. Herbert

Information Circular 6746 reviewed the fatalities in Indiana coal mines. for the fiscal year October 1, 1951 to September 30, 1933. Since then Indiana has changed its fiscal year to the period July 1 to June 30, but as most statistical data on accidents are arranged according to calendar years, the data in this paper are for the last 3 months of 1932 and the calendar year 1933, rather than for the new Indiana fiscal year. Tables 1 and 2 list the fatalities in Indiana coal mines3/ by cause and occupation for the last 3 months of 1932 and for the calendar year 1933. The fatalities for the small wagon mines employing fewer than 10 men are separated from those employing 10 or more men to call attention to the ex- tremely high fatality rate in small mines, largely because the State mining law does not apply to them nor do they come under the jurisdiction of the Indiana mine inspectors; as a result health and safety conditions are ex- tremely bad. During the last 3 months of 1932, 5 (approximately 42 percent of the total) fatalities occurred in the small mines, while for the calendar year 1933, 12 (approximately 32 percent) of the fatalities occurred in them. The Indiana Division of Mines and Kining estimates that these small mines have an annual production of approximately 325,000 tons, or about 4.5 percent of the total coal-mine production of the State. In other words, for these small mines the fatality rate per tons mined during 1933 was about 10 times as great as for the mines employing 10 or more men. Another lamentable feature in connection with the fatalities in small mines is that very few carry any compensation insurance and the owners are not worth enough financially for dependents of victims to collect anything under the common law; as a result, the dependents of those killed usually are left penniless and subjects of public charity.

Feb 1, 1935

By C. A. Alien

The increasing activity in oil shale has had a tendency to direct the attention of the industry to any substance from which gasoline or other oils can be secured . Cannel coal for many years has been known, as a source of oil and formerly it was the only substance from which kerosene was obtained . The name of coal oil was given to kerosene because it was derived from cannel coal before any flowing wells were brought in in the United States . In an isolated region in Southern Utah there is an unusually thick and clean bed of cannel coal which laboratory experiments indicate can be made to yield about seventy gallons of oil to the ton . This coal was first described in Bulletin 341 of the United States Geological Survey under the title of Colob coal field . This field lies at the western and southern base of the Colcb plateau and extends from the town of Cedar City southward to Kanarra and then southeastward to the town of Mount Carmel . Cedar City is 35 miles south of east from Lund on the Los Angeles and Salt Lake Railroad which is the nearest railroad point . Mount Carmel is about 90 miles south of Marysvale , on the Denver and Rio Grande Railroad , which is the nearest railroad point from the eastern end of the field . The Colob coal occurs in Lower Cretaceous rocks and a number of wagon mines have been opened on the seam in the vicinity of Cedar City , Kanarra , and Mt. Carmel , but between these places the field has been very little prospected . The cannel coal , so far as known at present , is limited to a small area on the head waters of the north fork of the Virgin River in Township 39 and 40 South , Range 9 East . In this region it occurs as a bed 5-1 /2 feet thick over which lies a layer of bituminous coal 2 feet and 5 inches thick .

Feb 1, 1921

By N. S. Dalal, X. Shi

"SUMMARYElectron spin resonance (ESR) measurements provide direct evidence for the involvement of the glutathionyl radical, as well as an isolable Cr(V)-glutathione intermediate in the Cr(VI) glutathione redox reactions. These results indicate a new mechanism for the reduction of Cr(VI) by glutathione in relationship to cellular environment and suggest that synergistic reactions of Cr(V) and GS· might be responsible for the (unexpected) increase in the Cr(VI)-induced DNA-strand breaks at high glutathione levels.INTRODUCTIONWhile the reduction of Cr(VI) by glutathione (GSH) is thought to be a critical' step in the pathogenesis of the Cr(VI)-exposure related carcinogenesis1- 4, the exact reduction mechanism is not yet understood. The following reaction steps have been suggested :(A) Initial step:Cr04 2- + GSH - GSCrOa - (1)(B) At high GSH levels:GSCroa- + GSH - Cr( IV) + GSSG (2)(C) At low GSH levels: GSC rO a - - Cr ( V ) + GS ·(3)Thus far, however, in these reactions, the GS· radical has eluded spectroscopic detection, while the evidence for the Cr(V) formation has been reported positives as well as negative2·. Her~ we present spin-trap ESR evidence for the formation of the GS· radical, and a definitive ESR detection of an isolable cr(V)-GSH intermediate in Cr(VI)-GSH reactions.MATERIALS. AND METHODSESR spectra were obtained at X-band (-9.7 GHz) using a Bruker ER200D ESR spectrometer. The magnetic field was calibrated with a self-tracking NMR Gaussmeter (Bruker, Model ER035M) and the microwave frequency was measured with a Hewlett-Packard (Model 5340A) frequency counter. The spin probes, a-(4-pyridyl-1-oxide) -N -tert-butylnitrone (4-POBN) and 5,5-dimethyl~1-pyrroline-1-ox1de (DMPO) were purchased from Aldrich, K2Cr201 from Fisher and used without further purification. All experiments were done at room temperature."

Jan 1, 1989

By Maria I. De Rosa

Table 46 and figure 16 show the number of fires and fire injuries for metal/nonmetal mills by state during 1990-2001. Table 46 also shows the injury risk rates, employees' working hours, and lost workdays. In all, 77 fires occurred in 26 states. Thirty-seven of the fires caused 41 injuries and 1 fatality (including 5 fires and 3 injuries involving contractors). The yearly average was 6.4 fires and 3.4 injuries. Fifty-four fires with 26 injuries and 1 fatality occurred at metal mills; 23 fires with 15 injuries occurred at nonmetal mills. The Ewhr value was 845 x 106 hr (Irr = 0.01), and the LWD value was 6,681. Minnesota had the most fires (16 fires and 5 injuries), followed by Arizona (9 fires and 3 injuries), Wyoming (8 fires and 3 injuries), Nevada (7 fires, 4 injuries, and 1 fatality), and Texas (4 fires and 7 injuries). Of these states, Texas had the highest injury risk rate value (Irr = 0.033). Table 47, partly illustrated in figure 17, shows the number of fires, fire injuries, fire fatalities, risk rates, employees' working hours, and lost workdays by time period. The number of fires increased slightly during the second period, then decreased during the remaining periods. The number of fire injuries show a decrease during most of the periods (an increase is seen during the third period), accompanied by a decline in employees' working hours during most of the periods. The Irr values follow patterns similar to those shown by the injury values. Tables 48-53 show the number of fires by ignition source, method of detection and suppression, equipment involved, location, and burning material by time period. Figure 18 shows the major variables related to fires for 1990-2001. Table 54 shows the number of fire injuries per number of fires causing injuries and total fires by year, ignition source, equipment involved, and location.

Jan 1, 2004

By John Owens, Marc Endicott, Hamid Maleki

This study presents a historic overview of the role of mobile roof support (MRS) technologies in improving stability and worker safety and presents the results of recent field evaluations of the MRS load rate monitoring device and other remote deformation-monitoring techniques. Field studies were implemented at two sites in cooperation among researchers from the National Institute for Occupational Safety and Health (NIOSH), Maleki Technologies, Inc., and J. H. Fletcher & Co. The objective of the field programs were to (1) study the interaction between MRS’s and coal mine strata and (2) develop and test suitable monitoring systems for assessing roof and pillar stability. An MRS consists of a roof canopy, four hydraulic cylinders, a caving shield canopy, and associated electromechanical systems mounted on crawler tracks. The machines are controlled by radio from a remote location and operate on self-contained power units. Typically, MRS’s have capacities of 5,340 and 7,120 kN (600 and800 tons). In comparison to posts, an MRS is capable of maintaining the yield load after significant amounts of roof-floor deformation. Because the mining cycle is accelerated, MRS’s help reduce the potential for time-dependent roof falls. MRS performance has been monitored in the laboratory under controlled static loading conditions and in the field under deep, two-seam mining conditions. Laboratory studies have quantified support capacity and system stiffness as a function of machine height. Field investigations have focused on determination of optimum operating conditions and development of warning systems that indicate excessive load on the machine and/or impending roof-pillar stability problems. Analyses of field data show that roof instabilities are influenced by (1) pillar failure, (2) pillar yielding, (3) mine seismicity, (4)geologic structures, and (5) panel layout designs and mining practice.Pillar yielding and failure (unloading) and seismicity can be conveniently monitored by the load rate monitoring device, but for consistent detection of roof falls, additional deformation measurements directly within the cuts are needed.

By David L. Moffatt

Considerable current interest is evident[l,2] in the use of transient electromagnetic methods for subsurface remote sensing. A transient method is discussed which uses a periodic video-type pulse containing a wide frequency range. A video pulse is used as an interrogating signal both for "target" identification and detection for relatively short depth (c 20 meters) applications in soil and soft rock media. If the medium is favorable, e.g., hard rock, greater depth applications appear to be feasible. The same procedures would be applicable for deep geological exploration but would require a substantial reduction in frequency and increase in target size. It should be noted that video pulse generators with 35 kv peak voltage and nanoseconds base widths are now within the state-of-the-art, thus significant power over broad spectral ranges is possible. In the design of a video pulse sounding system, 5 main problem areas can be identified; 1 ) selection of the pulse shape or spectral content of the video pulse, 2) design of a radiating structure which effectively couples such a pulse into the medium, 3) isolation of the radiating and receiving mechanisms, 4) realistically accounting for the dispersion and attentuation of the medium and the air-medium interface, and 5) interpretation or processing of the received signal waveform. Each of these problem areas will be discussed and illustrated with experimental and/or theoretical results. The Video Pulse Selection of the proper video pulse signal is dictated by 3 considerations, the maximum desired depth of penetration, the attenuation of the medium and the required resolution and size of the target. For a lossy medium, penetration and resolution are clearly at cross purposes and a compromise is necessary. The exact nature of the compromise is dictated by the application, but the spectrum of the video pulse should not contain any frequencies higher than the predicted cut-off, i.e., that frequency which is attenuated to the threshold level of the receiver. As a practical matter, it may be necessary to select 1 or 2 video pulses reasonably suited

Jan 1, 1973

By Sean Gallagher

Study Design. A split-plot experimental design was used to evaluate the influence of posture, trunk angle, and rotational velocity on peak torque output and myoelectric activity during maximal trunk extension maneuvers. Objectives. To determine whether the kneeling posture alters extension torque capabilities in isometric and isokinetic exercises as compared with standing. Also, to ascertain whether recruitment of trunk muscles is modified by such a postural change. Summary of Background Data. Factors such as workplace geometry may force workers to adopt awkward or unusual postures in the performance of manual tasks. An understanding of the limitations placed on strength in unconventional working postures is crucial to the proper design of jobs. Methods. Twenty-one healthy male subjects (mean age = 36 years 7 SD) performed 12 trunk extension exertions in standing and kneeling postures. Isometric tests were performed at 22.5°. 45°, and 67.5° of trunk flexion. isokinetic tests were done at three velocities: 30°/sec, 60°/sec, and 90°/sec. Electromyographic data were collected from eight trunk muscles to assess muscle recruitment under each condition. A prior; orthogonal contrasts were specified for analysis of both torque and electromyographic data. Results. The kneeling posture was associated with a 15% decrease in peak torque output when contrasted with standing; however, no concomitant change in trunk muscle activity was evident. Trunk hyperflexion (isometric tests) and increasing rotational velocity (isokinetic tests) were associated with reduced torque in both postures. Trunk muscle activity was primarily affected by changes in trunk angle and velocity of contraction. Conclusions. A reduced extensor capability exists in the kneeling posture, despite equivalent trunk muscle activity. The similar activation patterns in both postures suggest that the strength deficit does not result from alterations in trunk muscle function. Rather, it may be the consequence of a reduced capability to rotate the pelvis in the kneeling posture, due to a disruption of the biornechanical linkage of the leg structures. [Key words: electromyography, isokinetic, isometric, low back pain, posture. strength1 Spine 1997;22:1864-1872

By Edward Thimons, William A. Hertbrink

The effect of wind speed upon aerosol penetration into an idealized enclosure was studied The idealized enclosure was a painted plywood box that was 1 2X1 2 XI meters in volume Two fans supplied 1 7 m3 /min of filtered air to this enclosure at a static pressure of 2 8 mm of water The enclosure had a 7 5 cm diameter vent port which was isolated from the air flow around the enclosure To simulate holes in real enclosures, three 16-cm diameter holes were drilled on the front and back sides of the enclosure This simulated enclosure was placed in a tunnel-like structure The air flow from an ultra-light air craft was directed at the front of the enclosure The air speeds were varied between 14 and 36 km/hr as measured by rotating vane anemometer Static pressure in the enclosure was measured with an electronic manometer Two optical particle counters measured the particle number concentration of particles between the 0 35 to 0 5 µm inside and outside of the enclosure Aerosol penetration into the enclosure was computed as the ratio of the aerosol concentration inside the enclosure to the concentration outside of the enclosure The enclosure static pressures measured increase from 2 8 to 3 4 mm of water (P=00001) Aerosol penetration into the enclosure increased linearly with air velocity above 20 km/hr Theoretically estimated penetrations were correlated with observed penetration into the simulated enclosure When simple linear regression was used to model the observed penetration as a function of the estimated penetration, the value of the slope was 0 69±0 12 and the P value for the regression model was less than 0 0001 These results indicate that enclosure static pressure needs to be higher than the wind's velocity pressure in order to minimize aerosol penetration into these enclosures

Jan 1, 1999

By J. W. Thompson

ESTATE IN MINERALS. Minerals beneath the surface may be made the subject of separate ownership either by a grant of the minerals by the owner of the land or by a grant of the land excepting the minerals, and thereby an estate in fee simple is created in the minerals, as corporeal things real. Colby, In re, Iowa, 169 Northwestern 443, p. 444. DEEDS EXCHANGING DIFFERENT MINERALS-RIGHTS OF PARTIES. The lands of two adjoining owners were underlaid with cement rock and clay at a depth of about 100 feet from the surface and with coal veins some 600 feet below the surface. By an exchange of deeds one of the land owners conveyed to the other the cement rock and clay with the right to mine and remove the same without entering upon the surface, but the deed contained no covenant not to injure the surface. The other deed conveyed the coal seam and so much of the rock and other minerals just above and below the coal as might be required in connection with the mining and removing of the coal, together with the right to mine and remove the same, and the adja- cent rock, clay, and other minerals, without entering upon or injuring the surface, with one immaterial exception. The deeds do not define the word "surface" and neither expressly nor by implication did they secure to the coal owner the right to subside the overlying cement rock; but the implication is to the contrary, as the deed gives the right to mine and remove coal without entering upon or injuring the surface. The provision that the coal owner should not enter upon or injure the surface amounts to a clause that the coal mine. shall not be worked so as to let down the surface and this does not create any inconsistency with the provision giving the right to mine and carry away the coal.

Jan 1, 1919