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By Werner Goldsmith

This discussion is confined to the first section of Professor Clark's paper entitled 'Elastic and Nonelastic Waves' and its application to wave propagation in rocks. Some published results by other investigators concerning measured decay of peak strain and variation of pulse duration with travel distance are cited, but the principal subject of this section is a detailed mathematical analysis of spherical (and, to a lesser extent, of plane) wave propagation in various homogeneous, isotropic media. The materials selected include an elastic substance, a Voigt and a 'modified' Voigt solid-the latter incorporating the assumption of a constant loss factor (defined here as the product of frequency and the ratio of the imaginary to the real part of the shear modulus)-and a solid friction model. While other possible representations of a solid continuum model are mentioned, corresponding solutions are not presented. The pulse inputs considered comprise exponential decay, a unit step, and steady- state sinusoidal excitation: the process of conversion from one solution to another in the operational plane is indicated. The basic problem relative to the analysis of wave propagation in rocks concerns the specification of the appropriate material behavior, since the equations of motion for a given geometry of the source and medium are well established. In principle, the required information can be deduced from two types of measurement: 1) field observations of underground explosions or seismic disturbances, and 2) laboratory tests on small samples of the pertinent rock. However, in practice both types of approaches are beset with difficulties and subject to valid criticism. Field observations must be carried out under relatively uncontrolled conditions, including, in general, a lack of knowledge of the precise arrangement of the medium, stratification, faulting. inhomogeneities, etc. Specimens investigated in the laboratory can not represent the environment found

Jan 1, 1967

By Alexander Anderson

In many oil fields a great variation in the production of adjoining wells has long been observed, and a certain proportion of dry holes, situated between prolific producers, has been regarded as normal without thorough investigation as to cause. Similarly, an occasional prolific producer has been found in a part of a field where all other holes have proven disappointing. Adjoining wells which showed an unreasonable difference in production have been surveyed, and the bottom of the poorest producer has been found to have lost sufficient vertical depth, through its drift, to diminish seriously its penetration in the oil zone. Again, the bottom of the good producer has been found to he more favorably situated by its migration up structure. Surveying of wells in California fields has shown many instances where the dry hole has drifted far off the structure to such a degree that no amount of deepening could ever convert it into an oil well. In other cases, edge wells have been found to drift into the field. At this time, in California, the surveying of oil wells is beginning to he accepted as a routine part of operating procedure. Some operators are surveying all of their new wells and, in some of the recently discovered fields, this practice is providing invaluable assistance in methodical development. The information that has been obtained from the surveying of many wells has convinced most operators that it pays to give careful attention to the drilling of wells. Chews are now usually cautioned to avoid reckless competition with each other. Whereas, formerly, certain companies demanded a large footage from their drillers, they now issue orders that a very moderate speed in drilling shall he maintained and that every care be taken to avoid practices likely to cause excessive deviation of the hole frorn vertical. As a result of these new instructions to drilling crews, a distinct decline in the average drift of the wells drilled by these operators has taken place and fewer dry holes are being drilled from good locations. To the petroleum engineer and the geologist, oil-well surveys provide the necessary data required for the construction of the correct cross-

Jan 1, 1929

By E. W. Krampert

The oil industry was very active in Wyoming in 1936, in contrast to the several quiet years preceding. Production for the year again increased about 7 per cent, following an 8 per cent increase in 1935. During the year, 85 oil wells were completed, compared to 55 in 1935. Three gas wells were completed in 1936, and three in 1935. At the end of the year 45 wells were drilling, as compared to 55 drilling at the end of 1935. Two new oil fields and one new gas field were discovered in Wyoming during the year. In the year 1936 Wyoming produced 14,475,431 bbl. of oil, a gain of 1,001,081 bbl. over the 1935 figure of 13,474,350. This increase, in the main, was due to the taking of light oil from the newly developed Sundance sand pool at Lance Creek, and from the new fields, Quealy and Medicine Bow, which contributed their first production this year. Most of the other old fields either were partly shut in in competition with the new fields, or showed a normal decline. This was especially noticeable in the black-oil fields, where production had been slowly but steadily increasing for a number of years. During 1936 black-oil production decreased approximately 100,000 bbl. as compared to 1935. The only black-oil field to show marked increase was Garland, which managed to take the market from less favorably located fields. The production of Wyoming in 1936 was 11,358,757 bbl. of light oil and 3,116,674 bbl. of black oil. Salt Creek, with a production of 6,015,000 bbl., is still the largest single oil-producing field, accounting for 42 per cent of the year's total production. Lance Creek, an old field, with newly developed production in the Sundance sand, reached second place this year for the first time in its history, with a production of 1,878,486 bbl. Lance Creek production will almost equal that of Salt Creek in 1937, if the present rate of production is maintained during the coming year. Oregon Basin, a large black-oil field, held second place in 1935, but owing to a greatly lessened demand for its production, dropped back to third place in 1936. This was in part due to greatly increased light oil available, and in part to the greater supply of black oil available at

Jan 1, 1937

By J. M. Morris

THE point to be made most clear in this paper is the economic value of flotation in the Benguet mill flow sheet. It is rather a statement of effect with no attempt at a technical explanation of the cause. Certain well-known, easily understood reagents, mechanisms and principles have been adapted to the conditions at Benguet, and have proved to be more successful than was demonstrated in the laboratory. The mechanical and metallurgical development of this particular operation was arrived at by trial and error, with fortunately very little error. Changes were slow, of necessity, which in the end proved a blessing in that time was afforded for observation and analysis of the disturbing factors; and as a result each change was a definite step towards higher efficiency. Many of these steps were unpredictable from labora-tory work because of the varied and differing characteristics of ores met with in daily operation of the mill, which were practically impossible to reproduce on a laboratory scale. The Benguet mill receives daily ores that differ as much as if they were delivered from three different properties. There is first the surface and upper-level zone, which produces an oxidized secondary ore contain-ing considerable iron oxide, manganese oxide and some organic matter. Formerly, most of this ore consisted of very soft fill with some hard rock mixed in. It also contained an unusual amount of iron and aluminum sulfate, which formed hydrates upon entering the alkaline cyanide solu-tion and caused excessive frothing. When flotation was introduced in the Benguet mill the general char-acteristics of this upper-level ore had changed considerably, in that it was practically all newly mined, fairly hard ore. It still contained many of the same disturbing elements, but was somewhat simpler to treat than formerly. The small proportion of fines is still troublesome in flotation, and plant practice probably does not show more than 80 per cent extraction on this small portion of the ore. No definite figure on this is available, as this particular ore is delivered at irregular intervals

Jan 1, 1936

By S. C. Hollister

An evaluation of the function of the engineer, so that means whereby education can best serve his needs can be adopted. THERE has been a steady increase in specialized branches of engineering during recent years. Some of these are simply specializations in the function of engineering, such as welding engineering, tool and die engineering, petroleum engineering, and refining engineering. Others are associated more closely with the basic sciences, as for example, geological engineering or engineering physics. Still others tend toward the border line of business, such as administrative engineering or general engineering.

Jan 1, 1950

By Iichiro Omori

THE Mabuki process, a Japanese hearth process for the treatment of matte, uses the same princi-ple as the Bessemer steel process. The only difference between the two is that in the Mabuki proc-ess a hearth furnace, not a converter, is used. Though the hearth is not as good as the converter, the first cost is very low and the capacity is compara-tively small; so the process is most suitable for smelters FIG. 1.-PLAN AND SECTION OF HEARTH. having a small production. To construct the hearth, an excavation, 6 ft. in each dimension, is made in the ground and a drainage channel is dug at the bottom. Then all side walls are faced with stone or slag brick and the cavity is filled with fireclay or brasque, except the hearth at the top.

Jan 9, 1922

Jan 1, 1938

The October issues* of the Journals of the three AIME Societies carried a brief resume of the historical development of various technical and professional organizations which in some immediate or remote way affect the individual member of AIME. This resume was presented by the Institute Committee on Inter-Engineering Society Cooperation. Recently, several plans have evolved designed as a first step to provide a so-called "unity organization" for the entire engineering profession. Almost all of the plans involve Engineers' Joint Council, Engineers' Council for Professional Development, and National Society for Professional Engineers in some way or other. Hence our committee is presenting to our membership a resume of the recent activities of the two umbrella organizations and of NSPE. More detailed information on any of these organizations may be obtained from annual reports published by the organizations.

Jan 2, 1961

By P. H. Griffin

WHEN a subject, such as the manufacture and service of chilled car wheels, as has been fruitlessly discussed for ten or fifteen years, it is difficult to revive interest and action by the mere repetition of statements and arguments that have been made before. And when a situation involves serious responsibilities for conditions that have grown up under circumstances beyond the control of any particular individuals or authority, it is even more difficult to deal with. But there is one phase of every subject that need not involve these particular points if presented in a, proper manner; and that is, " the future state." I will try to present the subject of this communication from the latter standpoint and with the hope that all of those interested will feel disposed to give the matter attention from the basis that it is a, vitally important one to all that travel on railroads, whether as employees or officials, or as dependent on those in charge of the operation, or in the matter of materials and equipment used. The conditions of chilled wheel service have been changed so radically in the past ten or fifteen years by the use of freight cars of 40 and 50 tons capacity, that it is fair to say in the interest of all concerned in the use and in the manufacture of such wheels, that the increased strains and loads have been quite sufficient to account for much of the service results that have transpired. That proper provision was not made for increased possibilities of strength and wear, in fact that previous factors of the kind were allowed to deteriorate, is no proof that such wheels cannot be made equal to heavy service conditions as shown in the data given herein.

Jan 10, 1913

Jan 1, 1968

By Jan M. Mutmansky, Y. J. Wang

Mine ventilation analysis is an engineering discipline that can be considered a branch of the body of science known as network analysis. Likewise, the group of engineering procedures known as the critical- path method (CPM) is considered a branch of network analysis. It is therefore not surprising that mine ventilation network analysis and CPM have many similarities. These similarities are useful in analyzing several types of mine ventilation problems and will be utilized in this paper. The analogy between the free split in a ventilation circuit and the critical path in a scheduling network has been recognized by Owili-Eger (1973). While this was recognized as a property of a general ventilation network, many important applications to controlled- splitting problems also exist. The mathematical procedures necessary to apply CPM and network methods have previously been presented (Wang, 1981; Wang, 1982). This paper will illustrate the implementation of these methods by application to mine ventilation networks.

Jan 1, 1982

By Eric A. Nordhausen

A good deal of dialogue has been published and voiced concerning one mining regulation or another, that, according to those raising the issues, in effect shuts down or drastically reduces mine and/or mill reduction. The objective of this discussion is to there fore synthesize the various regulations affecting the uranium mining industry and attempt to realistically assess the extent of impact to yellowcake production - on both an individual and collective basis. Emphasis is placed on the later or newer permitting requirements under the Mill Tailings Act, Underground Injection Control Program, the Consolidated Permit Program, and the Resource Conservation and Recovery Act (RcRA).

Jan 1, 1980

By W. M. Brown

SEQUACHEE Valley includes portions of the counties of Marion, Sequachee, Bledsoe and Cumberland. It extends in a general direction parallel with the Great Valley of East Tennessee, some 75 miles northward from the Alabama state line. It is separated from the Valley of East Tennessee by a mountain arm about a dozen miles wide, known as Wallen's or Walden's Ridge. The genesis of the valley, geologically speaking, is simple. It is an erosion-valley along the axis of an anticlinal. The point of the wedge remains in a row of low "saw-tooth" hills, running up the center of the valley. These hills are of Lower Silurian age, and consist of Trenton limestone, covered and protected in some measure by chert. Walls of Carboniferous age form the inclosing mountains on either side; whilst a magnificent arch of Hudson River, Niagara, Hamilton and Subcarboniferous strata closes the valley at the

Jan 1, 1886

By J. K. Stanley

IT has been known for many years that the magnetic properties of a ferromagnetic material are very sensitive to internal strain. Any structure-sensitive property such as ferromagnetism, which is a-function of the regularity of the atomic arrangement, and discontinuities such as grain boundaries must show deviations from an equilibrium state when the regularity of the lattice is disturbed. Experience has shown that such distortions have a marked effect on the magnetic properties of a ferromagnetic material. The purpose of this paper is to show the feasibility of using magnetic methods in detecting internal strains. More specifically, it will be shown how such properties as permeability, remanence, and coercive force change on cold- working of aluminum iron and how these magnetic properties change during the annealing below the recrystallization temperatures. This work was conducted for two reasons. One was the desire to see in what manner strains are relieved in aluminum iron at low temperatures-a subject of practical importance in soft magnetic materials-and the other was the feeling that a study of cold-working and strain relief might shed some light honour understanding of what takes place in the deformation of metals DEFINITION IN TERMS It is necessary to define the terminology used in this paper because magnetic nomenclature is usually unfamiliar to the metallurgist, and certain other terms, such as recovery, have been used ambiguously by metallurgists and others. Magnetic terms are best explained by reference to the common hysteresis loop of ferromagnetic materials (Fig. I). In Fig. I the coordinates are magnetic induction, B, (ordinate) and magnetizing force, H, (abscissa). The c.g.s. unit for the magnetic induction is the gauss, the number of flux lines per square centimeter, and the unit for the magnetizing force is the oersted, the number of lines of force per centimeter in air or vacuum. If one starts with a completely de- magnetized specimen and magnetizes it, a typical virgin magnetization curve beginning at the origin is obtained. This curve is also the locus of tips of a family of smaller hysteresis loops. From this curve it is to be noted that the induction is not proportional to the magnetizing force, and that it appears to approach a limiting induction called the saturation value, and does so for values of H of 1000 oersteds. The ratio of the magnetic induction (gauss) to the magnetizing force (oersteds) is called permeability, p. Thus µ = B/H and if the magnetizing force H (oersteds) is specified as 10 or IOO oersteds, the permeability is written as µ10 or µ100. This is the accepted notation, and will be used in this paper. The values of permeability for H = 10 or 100 are chosen as indices for

Jan 1, 1945

By E. A. H. Tays

At the present time, the mine-owner has a number of patent crushers to choose from, when contemplating the erection of a mill; and a number of new ones are yearly brought to notice. We all know that the stamp-mill is the old standard; but several of the patent crushers, especially of the roller-type, are not without their merits. Having had a working experience, extending over a period of four years, with the " Bryan roller quartz-mill," working alongside of stamp-batteries, I take pleasure in giving to the members of the Institute the benefit of my experience with this mill.*

Jan 1, 1900

By H. B. Emerick

An effort has been made to evaluate the individual influence of various factors in steel making and rolling operations upon the surface quality of semi-finished steel products. The thoughts expressed are not entirely theoretical, but rather are based upon several years critical observation of mill yields and rejec-tions and are supported by actual data wherever this has been possible.

Jan 1, 1940

By J. P. Smith

Permian salt measures carry extensive lenses of soluble potash salts in north central Germany. Potash deposits of Oligocene age are found in the Upper Rhine Graben of Alsace (France), and in the Catalonian Basin of Spain. These deposits are found in a wide range of structural settings. Reserves are large, and the production of potash salts is an important phase in the economy of each of these countries.

Jan 1, 1950

By C. E. Shoenfelt

The most important development in an otherwise colorless year in Colorado oil fields was the completion, late in 1933, of a well on Iles dome on the western slope of Colorado, with an initial production of 1100 bbl. of oil. No great amount of activity beyond the drilling of necessary offset wells is to be expected as a result of the completion of a well of this size because the acreage on Iles dome is closely held; there is no pipe line outlet other than to the Texas Company's small refinery at Craig, 24 miles distant; and the market for the oil is limited to the demands of sparsely settled communities in the high mountains. The Iles field is located on a large dome developed in Mancos shale of Cretaceous age, and having a closure of approximately 400 ft. The structure is highly faulted on the southern end. The first commercial oil well on this dome was completed by the Midwest Refining Co. on the south side of sec. 22-4N.-92W. Oil of 37" gravity was developed in Nancos shale at 2560 ft. and water in the Dakota sandstone at 2630 ft., but a considerable amount of additional oil was found in the shale immediately overlying the Dakota. From 2630 ft., the well produced in 16 hr. 750 bbl. of fluid, 33 per cent of which was water. Production in the Sundance sand of Jurassic age was found in the Midwest Refining Company's No. 4 Parkinson, in the NE.-SW.-SE. of sec. 22-4N.-92W., and completed on the last day of the year 1926, for an initial production of 450 bbl. of oil at a total depth of 3242 ft. The well completed in 1933 is also a Sundance sand producer and was finished at a depth of 3447 ft. It extends the productive area of the field about a quarter of a mile cast. The Iles field is said to have a potential production of 5000 bbl. of oil a day from its present wells, but for the past year has been held at about 600 bbl. a day. The most important test, stratigraphically, ever drilled on the western slope of Colorado is the California Company's No. 1 Raven, NW.-SE. of sec. 30-2N.-102W., which had an initial production of 138 bbl. of oil of 32" gravity, in the Weber formation (Pennsylvanian) between 5750 to 6315 ft. It mas drilled to 7137 ft., probably near the base of the Weber, and then plugged back to 6315 ft. It was shot quite heavily with nitro-glycerin, but failed to respond. While the well can hardly be classified

Jan 1, 1934

By Ezequiel Ordoñez

THE great activity with which the oil resources of the northern Cantons of the State of Veracruz have been developed has largely resulted from the great success obtained by the important explorations carried out since 1902 in the Ebano district in the North, and several years later near Tuxpam, in the South. It must not be thought that these successes were quickly obtained, since the preliminary studies by good experts, the acquisition of what were thought to be the most promising coast lands, the extensive clearing thereof, and finally the number of unsuccessful drillings at great depth, signified an original outlay of some ten's of millions of dollars before finding commercial oil. The discovery of oil in industrial quantities at Cerro de la Pez, Ebano district, and the famous Dos Bocas gusher some years later, which was burned, once and for all made famous the Veracruz coast, where today is concentrated the Mexican output of mineral oil. In .1917, this production was nearly 50,000,000 bbl. It is well known that this output represents only a fraction of what the wells in actual production can furnish, because with adequate means of transportation and storage, the present extraction could be somewhat over 300,000,000 bbl. a year. These enormous potential oil resources of the Veracruz coast proceed from a relatively small number of wells, scattered over a few oil fields, separated from each other by large unexplored areas, wherein may be found other favorable fields which, in time, will undoubtedly become just as great centers of oil production. Experts who know our Gulf Coast believe that lands with commercial oil resources lie not only between the Panuco amid Tuxpan Rivers, but that indications are that the oil zone of Mexico, with more or less interruption, takes in the coast zone from Northern Tamaulipas to the foot of the Sierra Madre of Chiapas, and the banks of the Usumacinta River. This generalization is not merely the outcome of optimism, but is the result of the persistency with which one finds, throughout this Gulf Coast, the most usual characteristics upon which we depend for recognizing oil-bearing lands.

Jan 5, 1918

By Paul B. Barton

Unconventional mineral deposits are those that differ significantly from productive deposits in mineralogy, grade, or geologic setting. Thus, the initial representatives of each deposit type are, by definition, “unconventional” until they are exploited. The “unconventional” status changes to "conventional" because of economic shifts (e.g., bulk silver ores), because of technological innovations (e.g., froth flotation), or simply through the recognition of, and production from, novel mineral concentrations. Heretofore the discovery of new deposit types has been almost entirely accidental, but the long- established concept of the geochemical cycle provides a nearly untouched opportunity and challenge for the application of geochemistry in predicting novel, potentially economic, mineral concentrations.

Jan 1, 1983