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By A. S. C. Owili-eger

The computer-aided simulation model re¬ported here is an extension of the one developed by the author while at The Pennsylvania State University. The present model, however, includes consideration of the deformability and secondary fracturing of the porous system. The modifications enable simulation of multiphase shallow unsaturated-saturated and/or artesian ground water systems in dynamic mining environments. The model has been validated, verified, and evaluated on a number of field case studies and the results have been excellent.

Jan 1, 1984

By L. C. Brown, S. K. Behera

The diffusion rate in Ag-Sb couples is sensitive to con~pressive load with the width of Ag3Sb, the only phase present in the diffusion zone, increasing with stress up to 800 psi and remaining constant above this. Kirkendall marker experiments show silver to diffuse much faster than antimony in Ag3Sb and incipient porosity may therefore develop at the Ag/Ag3Sb interfnce restricting the transfer of atoms from the silver into the diflusion zone. Application of compressive stress reduces the tendency for porosity to develop and so increases the growth rate. In a recent paper Brown et al.1 observed a significant increase in the thickness of Cu2Te in Cu-Te diffusion couples on application of a compressive stress as low as 20 psi. Similar stress effects have also been observed in the Fe-A1,2 Al-u,3 arid cu-sb4,5 systems. It has been suggested that the increase in growth rates of intermetallic phases in these systems is due to a decrease in the amount of Kirkendall porosity with applied stress. In the present paper, results are presented of the effect of compressive stress on diffusion in Ag-Sb, together with a detailed examination of the Kirkendall effect. The Ag-Sb phase diagram6 shows that antimony has a moderate degree of solid solubility in silver, 5.7 at. pct at 350°C, but that there is essentially no solubility of silver in antimony. There are two intermediate phases— (hcp7) from 8.8 to 15.7 at. pct Sb and Ag3Sb (orthorhombic8) from 21.8 to 25.9 at. pct Sb. EXPERIMENTAL Diffusion couples were prepared from fine silver of 99.95 pct purity and from antimony of 99.7 pct purity. Both the silver and antimony were produced in the form of discs 1/2 in. in diam by approximately $ in. thick, with surfaces ground flat to 3/0 emery paper. Diffusion anneals were carried out in the apparatus previously described.1 A compressive load was applied to the diffusion couple through a lever arm system, with a reproducibility estimated to be ±10 psi. All runs were carried out in a protective hydrogen atmosphere. Following the diffusion anneal specimens were sectioned and polished and the width of the diffusion zone was measured metallographically. Composition profiles were measured using an electrostatically focused electron probe with a spot size of 10 , counting on Sb L radiation. Corrections for matrix absorptiori and fluorescent enhancement9 were not required. S. K. BEHERA, formerly Graducate Student, Department of Metallurgy, University of British Columbia, is now Postdoctoral Fellow, Whiteshell Nuclear Laboratories, Atomic Energy of Canada Ltd., Pinawa, Manitoba. L. C. BROWN, Junior Member AIME, is Associate Professor, Department of Metallurgy, University of British Columbia, Vancouver, B.C., Canada. Manuscript submitted June 14, 1968. IMD RESULTS Fig. 1 shows an electron probe traverse of a typical diffusion zone. In all couples examined only one intermediate phase was observed and the composition of this phase, 23 wt pct Sb, was in good agreement with the composition of Ag3Sb, 23 to 28 wt pct Sb. The presence of this phase was confirmed by X-ray diffraction of filings taken from the diffusion zone. The probe traverses showed no detectable solid solubility in either the silver or the antimony although the phase diagram indicates that some antimony, up to 6.5 wt pct pct Sb, should be in solid solution in the silver. However the width of this portion of the diffusion zone would be expected to be very small in view of the low diffusion coefficient in the silver, 4 x 10-l6 sq cm per sec at 350°C, 10 compared with that in the Ag,Sb, estimated as 3 x 10-8 sq cm per sec in the present work, and this region would therefore not be expected to be seen in the probe traverse. Application of stress resulted in a significant increase in the width of the diffusion zone, Fig. 2. At 350°C, the thickness of Ag3Sb increased from 250 at 0 psi to 400 p at the limiting stress of 800 psi, indicating an apparent 150 pct increase in the diffusion coefficient. Similar behavior was also observed at 400°C, indicating that the stress effect is not characteristic of just one temperature. The growth of Ag3Sb at 350°C and at various stresses is shown in Fig. 3. In every case the growth rate was parabolic indicating diffusion control. The kinetic curves all passed through the origin showing that delayed nucleation of Ag3Sb was not responsible for the stress effect and that it was a real growth effect. A series of tests were carried out in which diffusion was allowed to take place at a lower stress following an initial high stress diffusion anneal. Speci-

Jan 1, 1969

By J. W. Harden

THE observations here following are the result of an examination made as to the feasibility of extending the South Mountain Railroad from Pine Grove to Waynesborough, and of the commercial value of the ore through which such extension would be made to pass. The road at present built and in operation has a junction with the Cumberland Valley Railroad, half a mile east of Carlisle, and extends southward to Pine Grove, a distance of 176 miles. The extension proposed will add to it near 27 miles, making its total length 44$, more than 23 of which will run through, or in close proximity to, beds of ore. Along the route taken there are a number of openings at which the ore is gotten, of which the Craighead bank, Huntzinger's bank, Lowrey's bank, Wenkoop's bank, the Henry Clay bank, the Fuller

By H. M. Roberts

H. M. ROBERTS, Minneapolis, Minn. (communication to the Secretary*). -The rifling of drill cores is a frequent source of interest to men engaged in diamond drilling. Previous to the appearance of Dr. Crane's paper, there has been little record of connected observation or rigid speculation as applied to the cause of rifling. Replying to one of Dr. Crane's letters of inquiry, I ventured my opinion that the cause of rifling was a complex problem in physics, which I had not attempted to solve up to that time, except to ascribe it to the general cause of rotation and vibration of the rods. The question is worth attention not only as a matter of curious scientific interest but also for the reason that it stimulates thought on

Jan 10, 1916

By James A. Lewis

It is the purpose of this paper to show the importance of sand characteristics, when combined with other physical data, in evaluating production obtained by secondary recovery operations, and to indicate the benefits to be gained from the application of these principles to primary production.

Jan 1, 1942

By C. H. Wilson, J. J. Jakosky

In recent years geophysical prospecting methods have become well established as important steps in economically initiating new mining ventures in the field of base-metal exploration, placer mining and water-supply problems. The value of these methods as applied to these problems has been greatly increased by new and improved instruments, and a greater degree of skill in laboratory and interpretative technique. Considerable success has been attained, with subsequent drilling checking the predicted depths within 1 to 5 per cent, on problems requiring information on thickness of fill material, depth to and contour of bedrock, extent and yardage of gravels to be mined, and location of hydrostatic water table. In these applications the geophysical work gives data comparable to drilling, and at a cost of about one-fiftieth that of drilling. Discussion of several surveys with accompanying illustrations showing geophysical methods applicable to both simple and complicated placer problems are contained in the paper. The electrical instruments for measuring electromagnetic field strength and surface potentials are described, and their use, coupled with that of other geophysical instruments in modern field procedure, is noted.:

Jan 1, 1934

By M. Hayri Erten

In this research the possibility of pelletizing high grade fluorsoar fines or flotation concentrates with the use of calcined colemanite as binder is investigated, and the room temperature and elevated temperature strengths of these pellets are compared with those of pellets which are obtained by using bentonite as binder. Pellets of 10-12 mm. size and having 10% calcined colemanite showed a much higher room temperature strength than those containing 5% benonite, both being endurated at 1000°C for 15 minutes. However, when the same batch of pellets were tested at elevated temperatures of 250º to 500°C, bentonite gave better results. X-ray tests showed that in the pellets endurated at 1000°C for 15 minutes the original crystal structure of fluorite mineral is preserved.

Jan 1, 1977

By Edna A. Dancy, Gerhard J. Derge

The specific conductance of FeOx,-CaO melts in contact with iron was found to decrease from 200 ohm-1 cm-1 for FeO, to 40 ohm-1 cm-1 for a melt containing 26.3 pct CaO at 1400°C. The temperature coefficient was positive at all compositions, but became smaller at high CaO contents. Current efficiencies for electrolysis increased from 2.5 pct in FeOx to 17.3 pct at the high CaO composition, indicating a change from predominantly electronic conduction to conduction with a substantial ionic contribution. It was shown that Ca++ ions as well as Fe++ ions carry the ionic current. A subsidiary investigation on the apparent effect of atmospheres of argon, helium, and nitrogen on the electrical conductivity showed that this could be correlated with surface temperature losses, which varied with the thermal conductivities of the gases and resulted in precipitation of metal by the reaction 3 Fe++ = 2 Fe+++ + Fe. The work described in this paper is offered as a contribution to the general fund of knowledge concerning metallurgical slags. Measurement of electrical conductivity and electrolysis are comparatively trouble -free methods for investigating molten materials, but, although these methods had been used for complex slags, it was not until the work of Bockris et al.1 that the approach of examining simple binary slag systems was employed, and CaO-SiO2, MnO-SiO2, and Al2O3-Si9 were studied. Two groups have performed work of particular relevance to the present investigation. Inouye, Tomlinson, and chipman2 studied the conductivity of wustite as a function of temperature and of the addition of 5 mol pct of a number of oxides, including CaO. They concluded that molten FeOx in equilibrium with iron is a semiconductor. Simnad, Derge, and ceorge3 demonstrated the ionic nature of liquid iron silicate slags and also concluded that, although the conductivity of FeOx in equilibrium with iron is predominantly electronic in nature, there is a small ionic contribution. The work reported here on FeOx,-CaO slags consists of three main parts, namely, the determination of the specific conductance over a wide composition range, an investigation into the nature of the conductivity through current-efficiency measurements over the same composition range, and an attempt to identify the current-carrying ions, as well as a subsidiary investigation on the apparent effect of the nature of the inert atmosphere on the conductivity. EXPERIMENTAL Materials. The slags, varying in composition from FeOx to 27 pct CaO, were prepared by heating reagent- grade Fe2O3 in an ingot iron crucible with a suitable amount of CaCO3 and, in some cases, powdered iron, in air. This prefused material was then used for the runs. At the end of each run the cell was removed from the furnace and quenched by immersing the bottom half in water. After crushing, the slags were analyzed for calcium and total iron by the usual wet methods. The oxygen content was obtained by difference. Specific Conductance: Apparatus and Method. Fig. shows the experimental setup, with the conductivity cell and leads of ingot iron. The standard four-probe method for measuring high conductivities was used. In this, the potential drop across the unknown resistance is compared with the potential drop across a known resistance connected in series, i .e., same current through both resistances. Thus there are both current and potential leads to the center electrode and to the crucible, which acts as th other electrode. Both ac and dc circuits were available for the measurements; they have been described in earlier work performed in this laboratory.4,5 The geometry of the cell was such that the center electrode was equidistant from the bottom and sides of the crucible. This ensured that the current path was the same irrespective of the magnitude of the conductivity of the material in the cell. Cell constant were measured with KC1 or NaCl solutions, which have considerably lower conductivities (0.0013 to 0.25 ohm-' cm) than the slags, and this precaution in design made sure that the determined cell constants applied to the cells with contents of any conductivity. The cell-constant determinations were made with the ac measuring circuit to prevent polarization. The four-probe method eliminates lead resistance but not the resistance of those parts of the center

Jan 1, 1967

By H. W. Mead, C. E. Birchenall

SELF-DIFFUSION of iron in austenite is a process which may play a significant role in some of the practically important reactions which occur in solid irons and steels. It also provides a system in which the interaction of vacancies on substitutional sites and atoms in interstitial positions may be investigated. For both purposes, accurate values of the diffusivities are required. Two sets of previous measurements exist, each containing features which require checking. In the course of an investigation to determine the rate of diffusion of iron in certain steels, Garwick and Rosenqvist' measured the self-diffusion coefficient of iron in a 0.10 pct* C steel and obtained a dicated that while at lower temperatures D increased with increasing carbon content, at the higher temperatures it first increased and then decreased. At the same time the activation energy decreased linearly from a value of 69,000 cal per g-atom for pure iron to 33,000 cal per g-atom at 1.06 pct C. This rapid decrease in activation energy implies that iron at higher temperatures within the austenite range would diffuse more slowly in high carbon steels than in steels of lower carbon content. Experimental Procedure The radioactive iron used in this work was obtained from Oak Ridge National Laboratory. The unit consisted of about 1 microcurie each of Fe7 and Fe It was allowed to decay for two years. At the end of this time most of the Fe with a half-life of 46.3 days, had decayed, while most of the original Fe(half-life 2.91 years) still remained. The iron as chloride was extracted into an ether layer, using the method of Ashley and M~rray. After evaporation of the ether the iron chloride was dissolved in 250 ml of aqueous solution containing 2.4 gpl Fe. The compositions of the steels used are listed in Table I. Disks of ¾ in. diam and about ¼ in. thick were machined from these steels for use in diffusion couples. The disks were surface ground on both sides to ensure parallel opposite faces. One face of each disk was polished through 000 emery paper. Half of the prepared disks were plated with radioactive iron. For this, 1 ml of the radioactive iron

Jan 1, 1957

By C. B. E. Douglas

In an interesting article on evaluation of the water problem at Eureka, Nev., W. T. Stuart describes how a difficult water problem, or one phase of it, may be evaluated by means of a small scale test. Test data are plotted by a method rendering, under certain conditions, a straight-line graph that can be projected to show how much the water table will be lowered by pumping at any specified rate for a given time. A formula is then used to determine the size of opening, or extent of workings, necessary to provide sufficient inflow to enable pumping to be maintained at that rate. At first glance this might seem the answer to a miner's prayer, but a word of caution is in order. It may not be the whole answer. Moreover, results obtained by the method described are reliable only for conditions approximating those assumed. Even where conditions do not meet this requirement, however, it may be possible to draw helpful inferences from the results, perhaps enough to facilitate another approach to evaluation of a problem.

Nov 1, 1955

AN earthquake caused an upheaval in Japan, started fires which destroyed large parts of Tokio, Yokohama and Hakone, and with tidal waves and other consequences extinguished some 68,000 lives and much property right at the beginning of September." Also on Sept. 1, the Italians, offended by the murder of members of the Albanian frontier commission by Greeks, occupied the Island of Corfu, which was viewed as an act of war by Italy against Greece. An appeal by the Greeks to the League of Nations was flouted by the Italians. One of the consequences of these affairs was to throw discredit upon the League of Nations and to excite doubts whether it would be able to survive. On Sept. 19, Greece made the formal apology to the Allies collectively and following that the Italians with-drew from Corfu. During this month also the embroilment between Italy and Jugoslavia over the matter of Fiume came again into prominence. In Bulgaria there was a communist uprising which was promptly put down by the government. The whole country was put under martial law. On Sept. 13 there began a military revolution at Barcelona, in Spain. On Sept. 14 the king of Spain accepted the revolution and charged the leader with the formation of a new government. Cosgrave was reelected president of the Irish Free State, without there being any disorder. Great Britain paid the remainder of her silver debt to the United States, thus writing finis to the Pitman Act. The position of Germany went from bad to worse during September. The mark has become valueless and the business that is being conducted is largely on a gold basis once more, in terms of dollars and pounds sterling. Chancellor Stresseman announced Sept. 24 that the German government had decided to abandon pas-sive resistance to the French and Belgians immediately and unconditionally.

Jan 10, 1923

By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer's (refiner's) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner's product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristies of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economically sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydrocarbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates.3 Improved methods for refining lubricating oils from crude residual4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessitates an appreciable expenditure for equipment as well as added manufacturing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

By Robert W. Phelps

It is gratifying to observe the growing interest in the study of oil-well spacing. It should always be held in mind that the problem of optimum spacing is to obtain the maximum return of capital per acre drained. This naturally evolves.into a mathematical consideration. As mathematics is the basis of all science, an effort should be made to develop formulas which involve data obtainable in the early stages of development. The first information from a discovery well in a new field would be the character of the sand, rate of initial production of oil and gas, viscosity of the oil, rock pressure, etc. Later, from this well, if Herold's theories of hydraulic, volumetric and capillary controls are accepted, could he determined the ultimate production as without interference from drainage by subsequent well completions, and under which control the well is producing. If it should prove to be producing under capillary control, a rough estimate could be made of it's radius of drainage. With but one well, the radius of drainage, or the interference of drainage of individual wells by close spacing, would be estimated by comparison with similar conditions in other fields in which the development has progressed sufficiently to furnish the data. A second well that is spaced sufficiently close so that an interference can he observed after its ultimate production is estimated, will furnish data to develop a desirable spacing of wells which can be inaugurated for that area and which is capable of producing a uniform amount of oil under like conditions. In some fields this area will be extensive, in others each well location will require an individual study. In 1924, Cutlerl developed a scheme whereby he determined by tabulation a spacing of oil wells for the maximum return per acre. After a study of production in a number of fields, he developed the following as a tentative rule: "The ultimate production for wells of equal size in the same pool where there is interference (shown by a difference in the, production decline curves for different spacing) seems approximately to vary directly as the square roots of the areas drained by the wells. This rule may also he stated thus: The recovery from wells of equal size

Jan 1, 1929

By J. W. Rutter, K. T. Aust

Observations are presented of the formation of annealing twins during the growth of a recrystallized grain into a striated, melt-grown crystal of high-purity lead. The formation of an annealing twin resulted in replacement of the original migrating boundary by a large-angle grain boundary of the caincidence-site type or by a near-twin boundary. The results support the Fullman-Fisher theory of annealing twins and demonstrate the usefulness of the coincidence-site model. FULLMAN and Fisher1 have advanced the following theory to account for the formation of annealing twins during grain growth. Whenever a grain A grows into a matrix of grains S1 and S2, a twin A' of grain A may form, as shown in Fig. 1, if the following energetic condition is satisfied: where "E" and "a" refer to the specific interfacial free energy and the area, respectively, of the boundaries indicated by the subscripts. In effect, the twinned grain will persist when the energy of the boundary between the twin(A') and the matrix grain (S, or S,) is less than that of the boundary between the original growing grain (A) and the matrix grain by an amount which exceeds the energy of the coherent twin boundary between A and A'. Experimental observations on the changes in grain boundary free energy accompanying the formation of twins1 are in agreement with the theory outlined in Eq.[l]. Direct observations of the formation of annealing twins at moving grain corners1"3 and the depend-

Jan 1, 1961

By T. D. Tiemann

The purpose of this writing is to make available additional data, not previously published, on the extraction of silica from certain iron ores of Wisconsin and Minnesota and to discuss a possible method of processing. Results of investigations on the extraction of silica from low grade iron ores have been previously presented and discussed in detail in AIME Transactions.1,2 All of the ores investigated are essentially nonmagnetic and consist mainly of hematite, goethite and quartz. Much of the quartz is microcrystalline, particularly in the taconites. The ore from the Cuyuna range contains in addition manganese oxides. Briefly, the method consists in digesting a sample of the ore under pressure in a solution of sodium hy-

Jan 1, 1965

WALTER E. GASP, Vanadium, Colo. (communication to the Secretary*).-Having enjoyed associations with the authors of this paper while on the Anaconda geological staff, I want to express my appreciation of it as a contribution to economic geology very direct in its application to ore deposits. The conclusions reached seem to me to show that concrete generalizations can not be made over very wide areas as to structural relations of ore deposits, but taking each district separately data of great value has been presented. Looking over thin sections of Montana rocks, among these a collection belonging to Mr. Billingsley and some prepared by myself, one important point in the Butte area has come to my attention which I would like to discuss. Related to the batholithic intrusion, there are a number of various types of both the earlier andesites and the later rhyolites, especially of the rhyolite. Some of this rhyolite is composed- so predominantly of plagioclase and quartz as to be more properly called dacite, and near the volcanic centers the different phases are even more numerous, the quartz in some becoming a very minor constituent and confined to the ground-mass. Some portions of these rhyolitic extrusives assume ,deep reds and grays, and in the hand specimen may very easily be mistaken for andesite of the older period that has been altered by weathering or by baking near the intrusive granite contact; but thin sections of such specimens remove this color effect and present so clearly all the minute details of texture and mineral composition that they are in every respect identical and indistinguishable from the commoner types of the rhyolite. The andesites generally are augitic rocks with smaller plagioclase feldspars than the rhyolites and exhibiting a different arrangement. Therefore the so-called red and Clark gray andesite near Butte is not a portion of the pre-batholithic rocks, but a. phase of the rhyolite, and the authors, in assuming that "roof pendants or large inclusions of andesite are found

Jan 10, 1917

By R. A. Jr. Flinn

A CONSIDERABLE number of experiments in recent years have definitely established the fact that the internal friction or mechanical hysteresis of a metal under cyclic stress is a property that is highly "structure sensitive." Because of this fact, it has been suggested that an observa-tion of this property, which often is referred to as "clamping capacity," might he a useful indicator of structural changes taking place when a metal or alloy is subjected to any of a number of metallurgical treatments. Damping capacity is of interest to both engineer and metallurgist, but from a rather different point of view, and the information that each desires from such observations is of a different nature. The metallurgist is in search of various external indications of changes taking place in the interior of a metal; changes which are in themselves not directly observa-ble. Even if the observed phenomenon cannot be explained in funda-mental terms, it may be empirically related to certain characteristics of the material and prove of real value in research. Internal friction or mechanical hysteresis occupies such a position, and, although it is not well understood in terms of basic metallic theory, an observation of its changes can serve in a very useful capacity. Of course, there is nothing new in the measurement of damping, but the use of this property in metallurgical research constitutes a vast field, which has received all too little attention. The present work is essentially of an exploratory nature in this field and is an attempt to evaluate the process as a research tool. The phenomenon of age-hardening was chosen as a typical example of a structural change and one method of measuring damping was examined in considerable detail.

Jan 1, 1938

By Emmanuel P. Papadakis

Ultrasonic velocity measurements have been made to study the preferred orientation in cube-textured copper. Methods applicable to thin specimens were employed since the specimens were necessarily of sheet material. The measured velocities in various directions in the sheet differed from the corresponding values in single-crystal copper by 1 to 6 pet. The distribution of the deviations indicated that the align-ment of the (001) planes with the rolling plane was better than the alignment of the [100]and [010] directions with the rolling and transverse directions. Ultrasonic pole figures (velocity us orientation) are shown to be useful in the study of preferred orientation. THIS paper describes one set of experiments in a continuing study of preferred orientation in worked metals. This study has been undertaken to investigate the fundamental properties of metals when used as propagation media for ultrasonic waves. Many such materials are of current or potential use in ultrasonic delay lines. Fundamental studies on ultrasonic propagation parameters such as velocity, attenuation, and diffraction (beam spreading) are of importance in the design of delay lines, in the development of nondestructive testing methods, and in the study of materials themselves. Preferred orientation in worked poly-crystalline metals influences all three above-mentioned parameters, and hence is of particular importance. When polycrystalline metals are subjected to mechanical working, they develop textures dependent upon their crystal structure and the symmetry of the working operation.' The texture consists in the alignment of the crystallographic axes of the grains in preferred directions with respect to the symmetry axes of the working operation. Since the grains are elastically anisotropic, the elastic moduli of worked metals are anisotropic. Hence the velocities of elastic waves in worked metals depend on the directions of propagation and polarization. The worked metal may be thought of as taking on the elastic symmetry of a single crystal: so it possesses the same number of independent elastic moduli as the crystal class it simulates. In general, a worked metal does not adopt the crystalline symmetry of its own grains. For instance, most rolled sheet becomes effectively orthorhombic while all bar stock and wire develop hexagonal symmetry. However, certain metals with cubic crystal structure develop a cube texture upon rolling and annealing.= Nearly perfect alignment of [100]-type directions with the rolling direction, transverse direction, and rolling-plane norma1 can be achieved in certain fcc metals and alloys. These cube-textured rolled metals provide an excellent opportunity to test preferred orientation by means of elastic waves, since a worked metal with 100 pct cube texture would have elastic moduli identical to the moduli of its constituent metal. It is the purpose of this paper to present the results of an investigation upon cube-textured copper. Ultrasonic waves were used. The methods of measurement and the experimental results on the effective moduli will be given. The ultrasonic measurements will be shown to complement X-ray pole figures for the determination of preferred orientation in worked metals. EXPERIMENT To study cube - textured material, it was necessary to use thin-sheet material since a severe reduction in gage (95 to 99 pct) is necessary to produce cube texture. Special ultrasonic methods were needed to investigate the thin material at megacycle frequencies. A) Materials. The cube-textured material tested was a copper alloy containing 1 pct Zn. Specimens already measured for Young's modulus4 by Alers were kindly supplied by him. The specimens were slabs 3.00 by 0.25 in. cut from sheet 0.047 in. thick. The orientations of the long axes of the specimens with respect to the rolling direction were taken in 15-deg steps from 0 to 90 deg. B) Measurements. Two distinct experiments were performed to measure the phase velocity in these specimens. One measured the shear wave velocity for propagation in the 0.25-in. direction and polarization in the 3.00-in. direction. The other measured the velocity of both shear and longitudinal waves propagating in the thickness direction in the sheet. 1) Plate-Mode Measurements. The velocity of the zeroth-order shear mode5 was measured in the 0.25-in. direction in each strip. The specimens were ground thinner over half their length to assure that the first-order shear mode would be cut off below 6 Mc per sec, leaving the zeroth-order nondispersive shear mode as the only propagating mode. Piezoelectric ceramic transducers of 5 Mc per sec resonant frequency poled in their long direction were solder-bonded to the edges of the thin part of the slabs as in Fig. 1 after these edges had been made flat and parallel by fine grinding. These transducers produced waves polarized in the 3.00-in. direction and propa-

Jan 1, 1967

By Hans Von Höfer

Apart from the hypothesis of a cosmic origin (which failed of acceptance because it was not adequately supported by facts), the only important controversy concerning the origin of petroleum has been, for a long time, between the advocates of inorganic and of organic origin respectively. Each of these theories has had a long history of development, and is still being perfected, under the influence of two causes: (1) the increasingly extensive and thorough study of the oil-fields (of which new examples are periodically discovered and opened); and (2) the progress of synthetic experiments devoted to this question. Moreover, the advance in our physical and chemical knowledge of the properties of this peculiar natural product has necessarily modified all criticism of conflicting views. I. The Hypothesis of Inorganic Origin That the nation of an inorganic origin of petroleum, first set forth by Berthelot in 1866, and afterward ingeniously developed and formulated by Mendelejeff, should thus have proceeded chiefly from chemists, is quite natural; for the question was one of possible chemical processes in the earth's interior, and of imagined chemical reactions to be verified by ex-periment. Hypotheses of this kind were suggested by many chemists, of whom two, P. Sabatier and J. H. Senderens, may be specially named by reason of their highly interesting chemical experiments. Among geologists, Mendelejeff's hypothesis was received at first with much interest and favor; for it rested on the assumption of a central terrestrial mass of iron carbide, and the geologists had good reasons for adopting that assumption. Yet comparatively few of them attempted to furnish geological proofs of the hypothesis: the majority either silently believed in it, or for one or another reason rejected it altogether. An apparently weighty support of Mendelejeff's view was furnished by the American, G. F. Becker, who found in the oil-regions of the United States important and abnormal disturbances of the isogons of terrestrial magnetism, and inferred that in these regions the central iron mass must

Jan 1, 1915

By C. E. Feltner

In a recent note, Meleka and Hiarris1 have reported that the application of a constant strain rate Ad a superimposed cyclic stress to 99.99 pct polycrystal-line zinc at room temperature produced some marked effects in the resultant behavior. In their work, one end of the specimen was pulled in tension at a constant strain rate while the other end was subjected to a sinusoidally varying load (20 cps) of constant amplitude. For the slower strain rates and the larger superimposed cyclic loads, it was observed that the specimen could withstand strains prior to failure more than 100 pct greater than the fracture strains obtainable in simple unidirectional straining. This ductility effect was interpreted as being due to a cyclic stress enhanced thermal recovery process. It is the purpose of the present note to describe some related effects in 99.99 pct polycrystalline cadmium. Specimens were loaded in repeated tension at room temperature with a stress of sufficient magnitude to cause failure in about 1000 cycles and the accumulated strain was measured as a function of cycles and time. In addition, some specimens were subjected to a steady creep stress equal in magnitude to the peak value of the cyclic tensile stress. The resultant strain-cycle and strain-time curves for both types of test are shown in Fig. 1. It should be noted that the static creep specimen failed in about one third the time required to produce a cyclic failure but in the cyclic test the specimen was able to withstand a uniform strain before necking more than 50 pct greater than that possible

Jan 1, 1963