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By N. S. Dalal, X. Shi

"It has been recently suggested that the exceptionally high antitumor and antibacterial activity of natural fredericamycin A (FMA) is related to its ability to spontaneously generate the superoxide anion (02-) and hydroxyl (""OH) radicals in aerobic solutions [Hilton, B. D., Misra, R., & Zweier, J. L. (1986) Biochemistry 25, 5533]. With a view to understand the mechanistic details, attempts were made to reproduce earlier electron spin resonance (ESR) evidence for the oxygenated free radical formation in well-aerated solutions of natural FMA in dimethyl sulfoxide and dilute H 20 2• Little or no evidence was obtained for the formation of the 0 2- and methoxy (""OCH3) radicals, while the detected formation of the 'OH and methyl ('CH3) radicals was attributable largely to mechanisms not involving FMA. These results thus reopen the T question regarding the mechanism of its exceptionally high tumoricidal-bacteriocidal activity. This paper reports on an electron spin resonance (ESR) investigation of the formation of oxygenated free radicals in solutions of natural fredericamycin A (abbreviated as FMA) which has recently been reported to be a highly potent anti¬tumor antibiotic (Pandey et al., 1981; Warnick-Pickle et al., 1981). The impetus for this undertaking was provided by recent reports (Hilton et al., 1986; Stinson, 1986) suggesting that the strong tumoricidal activity with high therapeutic—toxic index of FMA was related to its ability for the spontaneous generation of superoxide anion (02-) and hydroxyl (OH) radicals. For example, the suggested mechanism for the formation of 02- by FMA was (Hilton et al., 1986)FMA-OH + O2 FMA-O + H+ + 02-Here FMA—OH is simply the FMA molecule emphasizing the —OH moiety which becomes FMA-O, the free radical rep¬resenting the oxidized form of the drug. While some other highly effective anticancer drugs in current clinical application, such as bleomycin, are also thought to exert their antitumor effects via the formation of reactive drug-based or oxygenated free radicals (Carmichael et al., 1985; Gianni et al., 1983), FMA was considered unique in that only in this case the free radical formation was thought to be spontaneous, rather than through a metal- or an enzyme-activated process (Hilton et al., 1986; Stinson, 1986). Thus it was suggested (Hilton et al., 1986; Stinson, 1986) that FMA could be the forerunner of a new class of anticancer drugs. However, we noted that while the hypothesis seemed plausible, the reported ESR spectral evidence appeared to be ambiguous. Because of the high significance of the earlier conclusions (Stinson, 1986), we undertook a systematic ESR study of the radical formation in FMA solutions, and as discussed below, our conclusions disagree with those reported earlier."

Jan 1, 1989

By Forrest T. Moyer

In conjunction -with the statistical survey of the lime industr-.r in 1939, by the Bureau of Hines, producing companies reported the lime-fuel ratios attained in their plants according to type of kiln and kind of fuel. Each ratio, expressed as the number of pounds of lime burned by a unit quantity of fuel, was weighted according to the tonnage of quicklime pro- . duced at the reporting plant and grouped with similar data from other plants, so that an average ratio for each type of fuel and,kiln could be calculated. By this method the variables trat affect ratios of individual plants are more or less equalized, and the computed average lime-fuel ratios provide a fair measure of kiln and fuel efficiencies during 1939.

May 1, 1941

By T. F. Morse, R. Lundstrom, A. J. Brammer, D. Peterson, M. Cherniack, T. Nilsson, J. D. Meyer, E. Toppila, G. Neely, N. Warren

HAVIC is a collaboration of investigators from North America, Sweden, and Finland having a scientific mandate from NIOSH, to study the exposure response relationship between vibratory tool exposure and adverse health effects. Five cohorts, the Suomossalmi forest workers cohort, Volvo truck cab workers, Connecticut shipyard workers, and matriculating dental hygiene students and experienced dental hygienists have been under study. In the case of shipyard workers, there was survey and tool exposure data from 1988, although detailed subject testing was only available within the timeframe of the study. The truck cab assembly workforce was an inception cohort that had been followed from 1994 along with age-matched controls. The Finnish forest workers had cumulative health data on a cohort (n=52) that had been studied from 1976. For a subset of these subjects, there was detailed tactometry testing in 1990, 1995, and 2003. Accordingly, there was historical as well as new prospective data for the industrial cohorts. The Suomossalmi cohort was reassembled only for our study, which precluded follow-up evaluation and because of retirement is almost certainly the last time this historic group will be studied. The study features are: • Characterization of the exposure response relationship for hand-arm vibration through a study design, incorporating multiple cohorts, some having existing historical data, • Selection of cohorts to include different types of vibration: oscillatory (forest workers) impact (truck cab workers), high frequency (dental hygienists) and mixed (shipyard workers), • Inclusion of two inception cohorts: dental hygiene students and Swedish truck cab workers, • Methods for multi-site and historical integration A description follows. [ ] Methods The study included surveys, physical evaluation, and a selection of battery of “best tests” (cold challenge plethysmography, multi-frequency tactometry, segmental sensory nerve conduction velocity [SNCV]1,2,3) applied across groups to quantify responses to exposure. Exposure monitoring included exposure characterization through daylong data logging at the individual level. Workers at each site were instrumented with a microcomputer-based Vibration Exposure Monitoring (VEM) system, developed at the Biodynamics Laboratory of UCHC and about the size of a police walkie-talkie, to record user-specific tool-operating times, vibrations, and grip forces throughout all, or a representative part, of their workday. More specifically, data logging methods involved the direct monitoring of work cycles, involving tool operation time and measures of tool vibration, namely the root-mean-square (RMS), root-mean-quad (RMQ), and root-mean-oct (RMO), and grip forces, each calculated per minute. For this study, the questionnaire was homogenized with other vibration studies4,5,6. Cross-translation was directed by the multi-lingual investigators, and then reviewed by the study team. To extend comparability with future international studies, questions were also added from the Vibration Network (VINET) draft questionnaire, the product of a European

Jan 6, 2006

By Frank E. Chase, John Rusnak, David Newman

During the past quarter century, coal mine geologists have evolved from providing a qualitative description of drill core and coal reserves into quantitative geotechnical specialists who bridge the gap between geology and engineering. In the late 1970’s and early 1980’s, hazard prediction mapping was in its infancy. At best, hazard maps identified rudimentary structures and conditions such as stream valley locations, sandstone/shale transition zones, and lineaments. A “technical disconnect” had existed between geologists and mining engineers as each profession operated largely independent of each other. Engineers did not readily integrate geology and geologic conditions, with the exception of coal thickness, into mine planning. Geologists were relied upon for reserve estimates and did not participate in mine planning or design. The employment and market slump of the 1980’s and 1990’s combined with mining more challenging reserves mandated that this gap be bridged and forced geologists to learn to speak more “numerically” to engineers so they could be understood. The purpose of this paper is to describe the procedures and thought processes used by coal mine geologists when determining various mineability and reserve extraction feasibility issues. The paper will also address underground geologic hazard mapping and prediction techniques. To achieve these objectives, the opinions and experiences of leading coal mine geologists, geotechnical and strata control specialists across the United States were solicited.

By John J. Gordon, Neil K. Cooperrider

The International Organization for Standardization (ISO) standard ISO 2631 [1,2] provides three methods for evaluation of human exposure to vibrations that contain occasional shocks or impacts. Part 1 of the standard specifies the running r.m.s. or maximum transient vibration method (MTVV) and the fourth power vibration dose value (VDV). Part 5 of the standard provides a method of computing the stress in the lumbar spine for humans exposed to multiple shocks. Alem et al [3] have reported application of these methods to data for tactical ground vehicles. This paper reports and compares VDV and spinal stress evaluations of more than 90 hours of vibration and shock measurements on North American locomotives engaged in through freight operations. The measurements evaluated in this paper were obtained for full crew shifts on 19 freight locomotive runs on mainline track in locations from New York to California. The shifts ranged in duration from 187 minutes to 497 minutes. The average speeds for the shifts were from 21.0 mph to 54.6 mph. All measurements were made on locomotives hauling freight trains in regular revenue service. Data Acquisition and Processing The results reported here were computed using test data acquired from a tri-axial seat pad, accelerometer at a sample rate of 400Hz with an anti-aliasing filter corner frequency of 100Hz. The VDVs and the lateral and longitudinal spinal stress values were computed directly from the acquired test data according to the procedures specified and described in [1] and [2]. The vertical spinal stress values were computed by converting the as-acquired test data to a sample rate of 160Hz for input to the vertical spine model, as required in [2]. The conversion of the test data from the as-acquired sample rate of 400Hz to the required sample rate of 160Hz involved up sampling or interpolating the test data to an equivalent sample rate of 800Hz, band limiting the resultant data with a low-pass filter corner frequency of 60Hz and finally down sampling or decimating the 800Hz data to a sample frequency of 160Hz. Discussion The vertical VDVs computed according to [2] for the 19 shifts ranged from 2.68 to 9.33 m/s1.75. In all but one case, the vertical values were greater than the values for the lateral or longitudinal directions. Note that the health guidance in [1] puts the lower boundary of the health guidance caution zone at a VDV value of 8.5 and the upper boundary at 17 m/s1.75. The daily equivalent static compression dose computed following [2] ranged from 0.123 to 0.434 MPa. Health guidance provided in [2] states that there is a low probability of an adverse health effect if the daily dose is less than 0.5 MPa.

Jan 6, 2006

By R. V. Ramani, K. V. K. Prasad, M. Swaminathan

"Engineering design involves, in addition to numerical calculations, considerable amount of expertise and judgement. The expertise and judgement is required to conceptualize and idealize the problem, select a suitable mathematical model for the problem and to interpret the model results in terms of stipulated design constraints. In recent years, knowledge based systems (KBS) have provided the capability to integrate the qualitative experiential and expert knowledge with ~he quantitative knowledge for improved analysis and design of systems. A possible KBS architecture for mine ventilation system design was discussed by Ramani and Prasad · (1987). The expert system (ES) component of the KBS supports the analysis and interpretation phases of the ventilation design process with an algorithmic program used for the solution of alternate designs. The purpose of this paper is to discuss the data and knowledge needs for developing such a system and a formal means of their representation on the computer. A number of ES shells were evaluated to explore possible development and delivery environments for the system. A brief summary of this evaluation is also provided.INTRODUCTIONLuxbacher and Ramani (1979) have discussed the design process of mine ventilation systems and have provided the interrelationships that exist between ventilation, strata control, drainage and material handling systems and mining methods. They have also outlined the importance of correct analysis of the problem, choice of the right solution method and a rigorous interpretation of the solutions. The expertise required for analysis and interpretation phases was identified as the key element in developing effective and efficient ventilation system designs. Such expertise is embedded in the right choice of questions to be asked of the user as well as in directing the user to a wide array of alternative methods that may satisfy the design requirements. With advances in artificial intelligence applications in recent years, particularly expert systems, the integration of expertise into traditional mine planning and design algorithms has been facilitated. These planning and design aids, employing the integration of numeric and symbolic logic and called coupled systems, are powerful tools for engineers to tap the benefits of experts (Kitzmiller and Kowalik, 1985; Fenves, 1985). The purpose of this paper is to discuss the means of representing knowledge for the design of mine ventilation systems through the use of a coupled system. The KBS is visualized as consisting of the following components:"

Jan 1, 1989

By A. W. Kbair, L. D. Gehl

"INTRODUCTION The rock-bit interaction during the cutting process in underground mines has been a matter of great concern to mining operators, researchers and manufacturers, particularly after the passage of strict environmental laws. Coal cutting bears directly on airborne coal dust generation and rock cutting generates frictional sparks which may cause face ignitions, jeopardizing the productivity, safety and economy of the industry. It is imperative to investigate into the factors which have influence on bit we.ar. Hurt and Evans (1981) concluded that the point attack bits have greater ignition potential than the conventional wedge shaped bits, and also worn bits were more responsible for ignition than the new bits. The results of a study (Khair et al., 1992) suggested that after 7% weight loss, the bit should be replaced. The polycrystalline compact diamond (PDC) tipped bits are reported to be cost effective in a study done by USBM (Twin Cities Research Center), and it was stated that the PDC tipped drill bits had 80 to 100 times longer life than the ordinary tungsten carbide (WC) tipped bits.This paper presents the results of the experiments which were conducted utilizing a coal cutting simulator at the laboratory of the Department of Mining Engineering, West Virginia University, USA. The description of the machine and the experimental set-up have been described elsewhere (Khair et al., 1989; Gehi & Khair, 1994), and therefore, will not be discussed here. The rock types which were used in experimen~ are Tennessee sandstone, Berea sandstone and Indiana limestone. The operating parameters include (1) drum speed, (2) water spray pressure and (3) bit type. Besides studying the wear characteristics influenced by the above mentioned variables, the effect of these parameters on the required cutting force, specific energy consumption, acoustic emissions rate and rise in temperature of the bit were also studied. A preliminary study was also done to compare we.ar characteristics of the WC bits with those of the poly-crystalline compact diamond tipped bits."

Dec 1, 1995

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 Raymond F. Farrell

A goal of the U.S. Department of the Interior, Bureau of Mines, is the advancement of minerals technology through the development of improved metals and minerals processing. In support of this goal, the Albany Metallurgy Research Center has developed atomic absorption spectrographic methods for the rapid analysis of A1203, CaO, Fe203, MgO, MnO, and Si02 in steelmaking slags. The application of these methods is discussed using an inexpensive pressure dissolution system. The overall coefficient of variation is 5 pct. The accuracy is the same as the reproducibility.

Jan 1, 1979

By E. J. Matson

The Little Castle Creek chromite deposit was examined in February and May 1941, respectively, by W. O. Vandenburg and O. H. Metzger, engineers of the Bureau of Mines. The Federal Geological Survey started a magnetometer survey of the area in November 1940 and completed its work during April and May 1941. Field work by the Bureau of Mines was conducted during May and June 1941. The purpose of the Bureau of Mines investigation was to search for a continuation of the chromite mineralization. The property at one time was the largest chromite producer in California.

Jan 1, 1949

By C. L. Chaney

Investigations were conducted to develop spectrochemical methods capable of determining 0.01 to 100 micrograms of metals in 50 milliliters of solution. The use of gallium hydroxide (Ga(OH)3) as a carrier-precipitant to concentrate metallic ions is described. A porous-cup graphite electrode is used to collect the precipitate. A specially designed plunger permits the electrode assembly to serve as the sample-containing electrode in the subsequent spec-trographic analysis. Analytical curves are presented for antimony, arsenic, beryllium, and zinc. Sensitivities of detection are given for 13 elements. The techniques were applied to identify impurities separated from tungsten, to determine trace impurities in solutions containing high concentrations of magnesium, cobalt, or nickel, and to identify trace impurities in hydrofluoric acid. Laboratory glassware was a serious source of contamination when low levels of zinc were determined.

Jan 1, 1963

By Isaac A. Zlochower

This paper presents data on the limiting (minimum) oxygen concentration (LOC), in the presence of added N2, of methane (CH4), propane (C3H8), ethylene (C2H4), carbon monoxide (CO), and hydrogen (H2), and some of their binary mixtures. It also addresses the issue of the flammable concentration (flammability) limits of these pure gases in air. The study is based on spark ignited explosions in large, spherical laboratory vessels (120-L and 20-L) using a 7% pressure-rise criterion for explosion propagation. The results of the study are compared with the older values which used long flammability tubes with a diameter >5 cm together with visual evidence of substantial upward propagation. They are also compared to results reported recently using a 12-L spherical flask with a visual flame propagation criterion. Finally, they are compared to results reported in Europe using more modest flammability criteria and smaller chambers. The findings reported here show excellent agreement between the 120-L and 12-L results, good agreement with the 20-L results, and reasonable agreement with the earlier flammability tube values for the lower flammability limits. They disagree, however, with the more conservative European values. These results and those from the 12-L experiments also feature lower LOCs than are given by traditional flammability tubes. A model for the LOCs of such fuel mixtures based on the Le Chatelier mixture rule for lower flammable limits is seen to reasonably fit the observed results on binary mixtures and can accommodate more complex mixtures as well. One such set of ternary mixtures containing CH4 and 1:1 CO:H2 is well fitted by the model.

Jan 1, 2009

By Ray J. Holmquist

"INTRODUCTION The Copper King or Red River copper mine was examined on December 13, 1942, by the Bureau of Mines at the request of Richard Kelly of Santa Fe, N. Mex. The examination was made to determine whether the expenditure of funds for rehabilitation work necessary to make the workings accessible for examination would be warranted.As a favorable report was made, the workings of the Copper King mine were opened and sampled under the direction of the author. The portal of the Copper King adit was opened first. Considerable rehabilitation was necessary in the first 50 feet of the workings, but the remainder of the drifts and crosscuts were sufficiently open to permit surveying and sampling.An attempt was made to open the Waterbury atilt, which was reported to be about 30 feet east of the Copper King portal, and to crosscut the ore body nearly to its southern border. However, slide rock and mine dumps had completely obscured the portal of this adit, and no opening into it could be found or made.Work on the project was started on September 27 and vas completed on November 6, 1943."

Apr 1, 1947

By Robert J. Hundhausen

This paper describes the methods and costs of sinking a 2-compartment shaft at the Hope mine, Clark Fork, Idaho. The Hope mine is owned by the Hope Silver-Lead Mines, Inc. Albert E. Nash, of Clark Fork, is president and manager.

Jan 1, 1948

By Alice V. Peter

Meerschaum or sepiolite is employed principally in tobacco pipes and cigar and cigarette holders, although a few other uses of minor importance are Down. The unique value of a meerschaum pipe is derived from the owner's pleasure in watching the color deepen with smoking and in having the color "set" at the desired shade. The name "meerschaum" (German for "sea foam") is applied because the material, when pure and dry, will float on water. Owing to its resemblance to the porous, bonelike structure of the cuttlefish, or septa, it is also known as sepiolite. There are a few scattered deposits of meerschaum in. the United States which have yielded a small product ion, but the world's supply of the' material is obtained fined principally from Asia Minor, Meerschaum deposits near Eski-Shehir, Turkey, are said to have been worked 2,000 years ago, but commercial exploitation is a development of the last hundred years DESCRIPTION AND PROPERTIES Meerschaum is a hydrous magnesium silicate (H4Mg2Si3010) having the following theoretical analysis: Si02, 60.8 percent; MgO, 27.1 percent; H20, 12.1 percent. It is a soft. (H.2 - 2.5), fine-grained, earthy, white, gray, or yellow material. It is very light weight when pure (specific gravity, 1 to 2) and is highly absorbent. Because of its porosity the proportion of water present in the mineral is affected by the humidity'of the atmosphere. In a moist atmosphere the water content may be as much as 21.7 percent. Then wet the material is soft and somewhat plastic. When dried again it becomes lard and tough. The toughness is especially apparent in some forms that have a fibrous or leathery texture.

Jan 1, 1934

By J. R. Bartels

Operation of underground coal mine mobile equipment is usually done in a restricted workspace with reduced visibility. This work environment puts machine operators in awkward postures for tasks that require awareness of their surroundings and fast reactions to avoid hazardous situations. Using experienced equipment operators as a source, researchers conducted an investigation that developed a method to gather data on the needs and practices of machine operators while controlling the machine and the reasons for needing particular operational cues. The method used was an interview technique including a survey questionnaire and visual aids. The data gathered defined operator cues and work positions for the cutting and tramming phases of remote controlled continuous mining machines used in underground coal mines. Analysis techniques to determine which cues an operator sees from a variety of positions utilizing a computer simulation is shown to be potentially useful to the mining industry for design of work practices and workplace layout and could impact equipment design and selection for improved worker safety. Conclusions indicate that the survey was a good research tool to collect data and helped investigators understand important visual cues. Using this information, researchers were able to analyze the visual cues an operator can see from a given work position and posture.

Jan 1, 2009

By BUREAU OF MINES

The cheapest method of handling gravel in placer mining operations is by hydraulic mining . In working gravel deposits by hydraulic mining , it is essential that an abundant supply of water under sufficient head can be economically developed and that there is sufficient grade for sluice boxes and for disposal of the tailing . Without dumping facilities , simple hydraulic mining is an impossibility . The cost of hydraulic mining may range from 2 cents a yard under favorable condıtions to 12 or even 20 cents under less favorable conditions and to 35 cents or more a yard in Alaska , according to conditions of operation , and if frozen gravel is encountered . When it is necessary to elevate gravel , the costs may exceed 60 cents a cubic yard . When the natural conditions do not permit of hydraulic pining proper , other methods of elevating the grade are employed , some of which are described below . Bucket dredging has replaced hydraulic mining in importance in California and other states where hydraulic mining was once extensively carried on , and is by far the cheapest method of elevating gravel when mechanical methods are required and the physical conditions are suitable for dredging . Dredging costs vary greatly under the different conditions encountered , and the total amount of gold to be recovered must of course be enough to warrant the cost of a dredge installation . Gold dredging operations in the United States are fully described in Bull . 127 , U.S. Bureau of Mines .

Jan 1, 1922

By Raymond B. Ladoo

The Bureau of Mines frequently receives requests for information on the mining , preparation and marketing of epsomite or Epsom salt , and in order to answer such inquiries the following information has been compiled . While it is probable that few people have considered epsonate as a mineral product , it will be noted that it should be so regarded and its production forms an important industry .

Mar 1, 1922

By J. S. Hansen

The U.S. Bureau of Mines developed a system for casting unique, slotted steel armor by modifying the conventional expendable pattern casting (EPC) process that is normally used for making aluminum castings. Three innovations were added to the EPC process to make the successful adaptation: (1) Vacuum was applied to sand molds, (2) continuous narrow-necked feeding systems were used to permit the casting of thin walls, and (3) fixtures were designed to prevent pattern damage and to hold critical casting tolerances, Potential problems and defects are described.

Jan 1, 2010

By Robert S. Sanford

This paper deals with truck haulage methods and costs at one of the many open-cut mines that are replacing rail haulage with heavy-duty trucks. At this mine, ore is trucked to a crushing plant, centrally located within one of the open-cuts. The requirements for efficient low-cost truck haulage are: Good trucks designed for heavy loads, adequate truck maintenance, smooth roads, and well-trained truck drivers The weighted average cost of hauling a long ton of ore to the crusher and the waste to the dump was reduced from $0.1993 in 1948 to $0.1114 during the last half of 1949, his corresponds to a cost per ton mile of $0.0864.

Jan 1, 1952