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By Joan Weinberg

The real gross national product (GNP) expanded by 2.3% during the second quarter, down from the anomalous 4.4% growth rate in the previous 3 months. If the expansion continues through October, it will have lasted 5 yr and become the second longest in 40 yr.2 As in the first quarter, improvement in U.S. exports played a role in the continuing--albeit slow--growth. More than 2 yr of declines in the dollar relative to currencies of other industrial countries have contributed to a slight reduction in the trade deficit in real (volume) terms, as real net exports of goods and services rose $1.9 billion (table 1). Exports grew a strong 12.1% while imports, which had fallen the previous two quarters, rose 7.4%. Manufactured goods and petroleum products accounted for most of the second quarter import increase. The American Petroleum Institute estimates that the volume of crude oil and refined products imports in the first half of 1987 surpassed those in the same period last year by 7.5%, reflecting falling domestic production and higher than expected demand. Expenditure on durable goods--those that last at least 3 yr-by both consumers and producers also contributed to the second quarter expansion. Personal consumption of durable goods rose 9.0%, after having fallen the two previous quarters. Motor vehicle purchases accounted for most of the second quarter increase and the first quarter decrease. Sales of automobiles surged in the last quarter of 1986, as consumers rushed to capture the sales tax deduction that was eliminated on January 1. Sales fell in the first quarter of 1987, but have now moved closer to the trend line exhibited in the first three quarters of 1986. Automobiles accounted for half the 0.8% July gain in retail sales, and two-thirds of the 1.4% June gain. Producers durable equipment purchases also rose this quarter, accounting for the increase in nonresidential fixed investment.

Jan 1, 1987

By Joseph J. Wallace

1. The Pittsburgh is the most important bed in Washington County from the standpoint of present production and recoverable reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 4,181 million short tons as of January 1, 1954. Of this total, 4,132 million short tons is in beds 28 inches and more thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1955

By J. A. Kosek

Work has been carried out under Bureau of Mines Contract HO 395132 to develop improved sensor cells for use in direct-reading detectors and diffusion exposure meters. A pumped CO sensor cell was developed which has a shorter response time, improved temperature cycle characteristics, and improved linearity and stability at high CO concentrations. Diffusion CO sensor cells have shown good response level stability and linearity up to 1000 ppm. In addition, a new sensor cell catalyst has been developed for NO2 sensor cells which has a much shorter response time and improved response stability characteristics.

Jan 1, 1982

By Arne Landsberg

A study of the chlorination kinetics of germanium, silicon, iron, tungsten, molybdenum, columbium, and tantalum has been made to determine the effects of temperature, chlorine concentration, geometric surface area and gamma radiation. The reaction products were volatile at the temperatures used this making it possible to follow the reaction rates by weight loss of the solid. Chlorination rates of germanium, silicon, and iron were found to be directly proportional to chlorine concentration while the rates for tungsten, molybdenum, columbium, and tantalum were proportional to the 0.5 to 0.6 power of chlorine concentration. A good correlation of reaction rate and geometric surface areas was not obtained because the true surface area of the samples could not be measured. Intense gamma radiation had no effect on reaction rates. The Arrhenius activation energies determined over the temperatures used are as follows: Germanium, 27 kcal/mole (233°-241° C); silicon 33 kcaL/mole (375°-517° C); iron, cold rolled, 20 kcal/mGle (259°-325° C) annealed, 21 kcal/mole (293°-337° C); tungsten, 43 kcal/mole (617-776° C); molybdenum, 37 kcal/mole (445°-4910 C); columbium) 34 kcal/mole (229°?255° C); and tantalum, 29 kcal/mole (370°-449° C).

Jan 1, 1965

By C. G. Kirkpatrick

Analysis of the data produced by a wide-band, sensitive, horizontal, biaxial motion sensor has revealed several distinctive patterns before, during, and after a roof fall. The signals prior to the roof fall are similar in spectra, but one thousand times larger in amplitude, than those after the roof fall. Immediately preceding the roof fall, by two to twelve hours, five events occurred which were larger in amplitude and lower in frequency than even the large pre-roof fall background signals. An interpretation of these events is offered.

Jan 1, 1979

By F. W. Lee

List of GEOPHYSICAL ABSTRACTS

Jul 1, 1932

By C. W. Smith

The U.S. Bureau of Mines; Tuscaloosa Research Center, in cooperation with the U.S. Army Corps of Engineers under interagency Agreement No. 14-09-0078-1510, conducted a comprehensive sampling program of 10 upland disposal sites along the Alabama, Black Warrior, and Tombigbee River systems in Alabama. Samples from each site were characterized according to particle size, chemical analysis, mineralogical content, and potential end use. Additionally, samples were subjected to the Toxic Characteristic Leachate Procedure to determine the presence of potentially harmful heavy metals. Based on the results of these studies, each sample was determined to have properties amenable for use as aggregate in general-purpose portland cement concretes and certain asphalt concrete applications.

Jan 1, 2010

By The Staff, Explosives Research Center

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1962, to June 30, 1963, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1963; in general, the research reported in these publications antedates the report period.

Jun 24, 1964

By D. G. Puglio

This Bureau of Mines study covers 25 underground mines that were active in the Upper and Lower Freeport and Lower Kittanning coalbeds in 1976. The coal ranges from low to medium volatile in rank; its primary use is for steam generation. Seven mines emit more than 100,000 cfd of methane gas; those mines are the deepest and largest producers. The methane gas content of three core samples of the Lower Kittanning coalbed was estimated by the direct method. A sample from a depth of 320 feet contained 0.5 cu cm of gas per gram, at 620 feet there was 0.8 cu cm of gas per gram, and at 1,060 feet there was 11 cu cm of gas per gram. These results suggest that methane control problems will be encountered in the future as deeper coal is mined.

Jan 1, 1979

By Linneas W. Laage

Coal production from underground coal mines has been important to the development of the industrial economy of the United States. Environmental problems have developed from some abandoned operations. These problems include: mine and refuse pile drainage, subsidence, unsafe mine openings and to a lesser extent mine gases, slope stabilities, mine and refuse pile fires and abandoned equipment and structures. Field investigations in three eastern coal mining districts, two in Ohio and one in Illinois, were performed to document the mine closure procedures used and subsequent problems that developed. The purpose was to identify, evaluate, and rank the seriousness of these problems. Based upon this evaluation, the undesirable present day situations could have been avoided or at least minimized by varying certain mining practices or mine closure procedures. It was found that federal regulations address all of these problems during the pre mining, active mining and post mining phases except for abandoned equipment which is the least threatening problem category. Ideally current practice would prevent future problems. However, the extensive and complicated nature of the legislation, environment and mining practices will necessitate adjustments to the law. The investigator recommends the following: 1) Goal oriented legislation encouraging complete resource extraction, standardization and compilation of mining generated hydrological data, periodic review of the coal mining regulations, and improved communication and cooperation between coal interests, regulators and the public. 2) Permitting effluent limitations to accurately reflect natural conditions. 3) Solidly back filling shafts and individual assessment of sealing or capping requirements. 4) Installing shaft vent pipes into the fill material to intercept and vent methane.

Jan 1, 1982

By H. E. Heide

The serious shortage of domestically produced asbestos during the war prompted the Bureau of Mines to investigate reported asbestos deposits in Alaska. The most promising' appeared to be these in the Cosmos Hills and Jade Hills areas along the Kobuk River in northwestern Alaska. The deposits along the west side of Shungnak River, a tributary of the Kobuk River, were the first to be investigated by the Bureau, in the summer of 1944. Four bulldozer trenches were excavated, from Which a 2-ton sample was taken. This sample was shipped to Rolla, Mo., for testing in the Bureau of Mines laboratory. In the summer of 1945 an investigation of asbestos deposits on Cosmos Creek, also a tributary of the Kobuk River, was begun; the work was completed during the field season of 1946.

Jan 1, 1949

By L. D. Schmidt

Now that the war is over, there is a great revival in popular demand to decrease pollution of the atmosphere in our cities. Great cities, such as Pittsburgh, are starting to enforce laws against violators of smoke ordinances. The substitution of low-temperature coke for bituminous coal in household heating is a most promising field for helping to eliminate the smoke nuisance. This Information Circular is written to assist in the very worth-while effort to reduce atmospheric pollution. Herein are de- scribed recent German developments in the production of low-temperature coke. Operating and cost data are given on German commercial-scale low- temperature carbonization plants.

Feb 1, 1947

By D. Harrington

For several years, or from about 1932 to 1935, inclusive, the coal industry of the United States had an excellent record as to coal-mine explosions. In 1937 and in 1938 to date there has been a definite increase in the number of explosions attended by considerable loss of life and property damage. In most of these explosions one important underlying and contributing cause has been lack of sufficient (or at least efficient) ventilation to properly dilute and remove explosive gas from the mine. This increase in explosions indicates that. the lesson taught through bitter experience, many times in the not far-distant past, of the need for good ventilation is frequently being overlooked, partly because the relatively good experience of the industry in the past several years has made many mining people forgetful. Moreover mining practices are rapidly changing, and in some instances the changes are being made with little if any regard for safety. It appears, therefore, that a review of some ventilation principles and practices should be of value in preventing further disasters; this paper has been prepared with that object in mind. In coal mining the need for thorough ventilation of all underground working places is recognized by both mining practice and law; such ventilation is generally obtained by the use of fans that circulate a quantity of air much in excess of the quantity of coal produced, by weight as well as by volume. For example, in a relatively small mine producing 1,000 tons of coal per day and circulating 100,000 cubic feet of air, which is by no means abnormal, 2,000,000 pounds of coal and approximately 10,900,000 pounds of air would be moved out of the mine every 24 hours. Because of the need for adequate dilution and removal of methane issuing or likely to issue from mine strata and for removal of the carbon dioxide formed by coal and timber oxidation up-to-date coal mines usually provide an air volume which if adequately coursed not only removes these gases but also the gaseous products of the detonation of explosives (which may include carbon monoxide, hydrogen sulphide, nitrogen oxides, carbon dioxide, and nitrogen) and the carbon

Jan 1, 1938

By Roy T. Sorensen

The Bureau of Mines has investigated the recovery of cell-grade alu-mina by RCI leaching of calcined kaolin in the alumina miniplant at its Boulder City (NV) Engineering Laboratory. Classification and thickening were used for separating aluminum chloride leach liquor from the siliceous residue generated in the acid leaching step of the clay-HCI process. Coarse solids were classified from fines at 115 mesh and countercurrently washed in three additional spiral classifiers. Fines were treated in a conventional five-thickener, countercurrent decantation circuit. When this method was applied to the solids-liquid separation of slurry from RCI leaching of minus lO-mesh calcined kaolin, 75 pct of the residue reported as classifier sands and 25 pct as thickener underflow. Predicted individual classifier and thickener area requirements were 6 and 25 ft2/tpd, respectively. Total thickener circuit flocculant requirement was 2.4 lb/ton solids. Aluminum chloride pregnant liquor was produced that analyzed 8.4 pct A1203 and contained more than 97 pct of the alumina in the liquid phase of the slurry. Bench-scale settling tests were used to correlate fines content of leach residue to thickener area and flocculant requirements.

Jan 1, 1983

By James J. Snodgrass

The Bureau of Mines designed and constructed a series of calibration models for geophysical borehole logging. A nominal hole diameter of 3 inches was selected as representative of typical core holes drilled for mining and engineering purposes, although additional hole diameters of 2, 5, and 8 inches are provided in one of the models for determination of empirical correction factors for variations in hole diameter. The physical properties of the models were determined by laboratory analyses of drill core samples and evaluated statistically for reliability. This report outlines the location of the models, elements of design and construction, and results of the laboratory tests. The models are available at the Denver Federal Center, Denver, Colo., for use by Government agencies and private industry to calibrate logging equipment for measurements of density, sonic velocity, magnetic susceptibility, and electrical resistivity.

Jan 1, 1976

By Henry Kreisinger, J. F. Barkley

This book is one of a series of publications being issued by the Bureau of Mines for the purpose of disseminating information in regard to the methods by which the fuels in this' country may be used most efficiently. A knowledge of the temperature of the gases in boiler settings and in other commercial apparatus using heat tends to develop improved designs of apparatus and better methods of operation, thus reducing waste of fuel. The following pages present, for the benefit of those designing, operating, and testing such apparatus, information as to the accuracy of temperature measurements made under certain conditions and the corrections that can be safely applied.

Jan 1, 1918

By Dale W. Richardson

Ductile hafnium was not obtained consistently by the conventional Kroll process. The bimetal reduction modification produced a more ductile hafnium by lowering the impurities, especially oxygen, in the sponge metal. Hafnium oxide was chlorinated in the presence of carbon to form anhydrous hafnium tetrachloride, which was reduced by sodium and magnesium in an inert atmosphere to produce sponge hafnium metal. After vacuum distillation to remove the byproducts, the sponge was arc-melted into ingot and rolled into strip. Metallic impurities were decreased by evaporating the hafnium tetrachloride from a fused salt. An excessive amount (over 1,200 parts per million (p.p.m.)) of aluminum was contained in some of the hafnium oxide, much of which remained as aluminum chloride in the hafnium tetrachloride during chlorination. Evaporation of the hafnium tetrachloride from a fused NaCI-KCI mixture during the Mg-Na reduction greatly lowered its aluminum content, as most of the aluminum and some of the other metallic impurities were retained by the fused salt.

Jan 1, 1961

By W. J. Wenger

Colorado has been producing petroleum since 1863 but only recently has become a major oil State. The first well was drilled on Oil Creek near Florence, but out-put was relatively small until discovery and development of the Weber sandstone reservoir at Rangely. Oil was discovered in the Weber sandstone in 1933, and the reservoir was developed after 1940, bringing Colorado, in 1949, to 11th place among the 48 States as an oil producer. Colorado's output increased further because of the discovery and development of many fields in the Julesburg Basin since 1949 By 1954 Colorado was in ninth place and maintained that position through 1955.4/ Between 1946 and 1951, Colorado's oil production more than doubled, while the total United States production increased only 25 percent. It seems probable that production will continue to expand in Colorado for many years. This report presents analyses of 92 crude oils from 73 fields representing 90 percent of the production in 1955. Abridged analyses are listed for easy comparision, and complete analyses arc given in the appendix. Oil samples were collected for study from many different sources. Although many of the newer fields were not sampled, their oils probably are very similar to those from corresponding formations that were studied and tabulated.

Jan 1, 1957

By Paul Averitt

The coal-bearing rocks in Iowa occur in an arcuate belt across the central and southern parts of the State (fig. 1) at the northern end of the Western Interior coal field. Coal beds of minable thickness are sporadic throughout this area and are mined principally in the three districts indicated by dark shading on the index map, although coal occurs also in the areas indicated by light shading. The coal is mostly of high-volatile C bituminous rank in all parts of the State. SURFACE FEATURES The coal-bearing rocks in Iowa are concealed for the most part by a covering of glacial drift ranging in thickness from a few feet to several hundred feet. This covering has been dissected to form a gently rolling upland, rising from an elevation of 466 feet at the mouth of the Des Moines River to about 1,200 feet in Calhoun County in the central part of the State. The local relief, however, rarely exceeds 150 to 200 feet.

Jan 1, 1949

By H. R. Babitzke

To develop alloys suitable for use at elevated temperatures, columbium and tantalum were combined with tungsten, hafnium, vanadium, zirconium, and titanium, and the resulting alloys were evaluated with respect to fabricability, hardness, Electrical resistivity, strength at elevated temperatures, oxidation resistance, and bend transition. Of the 23 compositions tested, Cb-2OHf-5W-10Ti exhibited superior high-temperature properties. A recrystallized sample of this alloy was fabricable at room temperature, had a strength of 44,000 psi at 1,200° C, and had an oxidation rate of only 7.7 mg/cm2/hr at 1,000° C.

Jan 1, 1966