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THE problem of picking the best students for an engineering college can no longer, be considered as simply one of determining the amount of general ability, but rather of finding special aptitudes for scientific work, according to Carl C. Brigham~ a Princeton University professor, who has been conducting researches on methods of selecting engineering undergraduates at Cooper Union, an evening school in New York City. When we first began this investigation seven years ago," says Dr. Brigham, "we thought the whole job would be done a soon as we had found a good method of measuring general intelligence. Today we feel that we are still about five years away from a solution, but on somewhat firmer footing than when we were looking for general ability.

Jan 1, 1928

By J. R. Hillebrand

From the abstract, "A realistic ore deposition model to serve as a conceptual framework." Further, on page 246, "The first area of study was the Josephine peridotite, now identified as an ophiolite terrane, located in northern California and southwestern Oregon (Fig. 3). Here, it was felt that we could test the models shown in Figs. 1 and 2 and, if successful, expand the model and test it in other chromite districts in the US and around the world." My comments refer only to chromite deposits in Europe and the Middle East. First, I question that may chromite deposits occur in the idealized ophiolite section shown in [Fig. 1]. Second, although some podiform deposits (referring to morphology) have been important (Gulernan, Turkey, for example), the stratiform deposits are of greater importance in tonnage and frequently grade. Examples include Nada, Yugoslavia; Bulqiza, Albania; Xerolivado, Greece; Saranovsk, Russia; and Abdasht, Iran.

Jan 1, 1984

By D. D. Pollock, G. P. Conard II

Equations of the form of the Mott and Jones equations for the absolute thermoelectric powers of metals are derived primarily from a thermodynamic approach. The behaviors of transition thermoelements in common use are then examined and compared with this simple theory. MOTT and ones' derived a general expression for the absolute thermoelectric behavior of metals and alloys using the approach of the solid state physicist. This expression was then applied to specific cases.1,2 The present work develops equations of the same form principally by a thermodynamic approach. These relationships are then employed to gain some insight to the behavior of the transition thermoelements in common use. I) DERIVATION OF AN EXPRESSION FOR ABSOLUTE THERMOELECTRIC POWER First consider a metallic conductor which is maintained in a temperature gradient with no current flowing. At constant pressure, there will be a gradient of the free energy (F,) given by:

Jan 1, 1963

By T. S. Lundy, J. I. Federer

A graphical method has been developed and tested for separating the effects of grain boundary and lattice diffusion in polycrystalline materials. The method is based on the assumptions that for unidirectional diffusion from a plane source of radioactive material, the penetration of activity far into the specimen from the source is due solely to grain-boundary effects, and 2) pure grain-boundary penetration is described by a linear plot of log activity vs the perpendicular distance x from the source. The former is based on the fact that at any temperature the grain-boundary diffusion coefficient is always very large relative to the lattice diffusion coefficient; and the latter is based on the derivation of Fisher.1 Using these criteria along with appropriate penetration data (in this case, data for the diffusion of Cb95 in pressed and sintered UO2) one first plots the data as log activity vs x2 and as log activity vs x, as shown by curves 1 and 2, respectively, in Fig. 1. A tangent line to curve 2 for large x (curve 3) is then transferred to the x2 plot as curve 4. The subtraction of curve 4 from curve 1 yields curve 5 which represents only lattice diffusion and may therefore be related to the diffusion coefficient by using the appropriate solution to Fick's second law. It should be noted that the method has inherent inaccuracies for small and large values of x2 and only the subtraction at intermediate values can be used. For the illustrated specimen the calculated diffusion coefficient is 3.4 X 10-11 sq cm per sec at1445°C while data using a single crystal of UO2 at the same temperature yielded a value of 2.9 x 10-11 sq cm per sec.2 The same method of subtracting grain-boundary diffusion effects to obtain lattice diffusion coefficients has been successfully used to determine self-diffusion coefficients of Th230 in polycrystalline thoria.

Jan 1, 1962

By Hisaaki Takata, Nobukazu Nanko, Ichiro Izawa

INTRODUCTION Tochibora Mine belonged to Kamioka Mines, which are located in Gifu Prefecture, the cen- tral part of the Japanese main island, has occupied the important position as a main source of silver, lead and zinc for the smelter of Mitsui Mining & Smelting Co., Ltd.. The annual production of crude ore goes up to about 1 mil- lion metric tons with average grades of 20g/t Ag. 0.31% Pb, and 4.18% Zn. For the last 20 years, the mine has struggled with the depressed zinc metal price in yen and the escalation of operating cost, especially la- bour cost. For instance, prices of commodities and labour cost have been raised 8 times and 14 times respectively during this period. On the other hand, total operating cost has been con- trolled to increase 4.5 times. The productivity of the mine has been increased 4 times by means of improvement of individual works and adoption of perfectly mechanized trackless mining system to reform the mining method. Some improvements are presented as follows; Today, drifting is carried out by the tunnelling crew which consists of 9 operators equipped with 5 Mobile-Jumbos, 2 LHD's and a jeep for carrying and loading ex- plosives. In order to get the high utilization of these machines, each crew manages systematically and continuously adjacent 15 faces under the direction of a forceman. As a result, we have accomplished high advance of drift. Furthermore, raising is carried out by a set of the raise-borer in case of long raises like ore- passes and also by the stage blasting method in case of short ones like slot-cuts. Generally speaking, the sublevel stoping method is considered to be one of the best methods for various respects; high productivity, low cost, easy grade control and safety. This method has been introduced in Tochibora Mine since 1950 and is now widely applied to lodes that could not be mined before by this method be- cause of the shapes of them and the conditions of their country rock. Now we are convinced to be nearly accomplished for our method. This report presents some examples of the standard sublevel stoping method and its variations which are practised at the mine. STANDARD SUBLEVEL STOPING Up to 1979 since 1950 when this method was first applied at the mine, 17 million tons of crude ore have been produced by this method, which amounted to 55% of the total production of the mine. During three decades, the productivity has been increased considerably by means of trackless mining system using large-sized machines and etc.. In other words, mining efficiency has been increased from 20 tons/man.shift to 100 tons/man.shift at large stopes. Formerly undercutting was carried out above the drawing drift by jack-legs and small scrapers and then several cone-shaped glory holes were made by stopers between the undercut level and the draw level. But now, a undercut drift is driven in parallel with the haulage drift at the same level of it. And at the undercut drift, drilling upward is carried out by a large-sized machines like the fan drill in order to extract the broken ore directly at the drawing drift connected with the haulage drift. Simplification of the work as well as utilization of large- sized machines enables to get higher productivity. But if the deposit is comparatively wider and the broken ore around the middle part of the deposit cannot be extracted, several drawing drifts are driven to the deposit and in order to minimize dead ore at the final stage of operation, the

Jan 1, 1981

By R. R. Angel

Drilling rate is a parameter that should be considered in determining the volume requirements for air and gas drilling. The use of past methods which ignore the effects of the solids content upon the pressure and velocity of the annulus flow stream can result in undercalculation of the required volurne by as much as 50 per cent. A vertical-flow equation is presented for determining volume requirements. This equation includes the effect of the solids that are transported up the annulus in the flow stream by incorporating the drilling rate as one of the parameters. The effect of down-hole temperature on required circulation rates is also ana-lvzed. A simple approximate method of determining volume requirements is presented. This method is more accurate than the methods used in the past. Hole cleaning difficulties are analyzed for a recent air drilling job where past methods indicated that - excess air was being used. Sample curves of calculated boitom-hole pressures are presented for air and gas drilling in several hole sizes. INTRODUCTION In certain areas the use of air or natural gas as a circulating medium for drilling oil and gas wells is becoming a common practice. Large increases in penetration rate and bit life are achieved through the use of these media in preference to mud or water. Drilling rates as high as 90 ft/hr have been obtained in shales. The importance of maintaining adequate circulation rate is generally recognized; however, much disagreement exists among drilling operators as to what constitutes "adequate" circulation rate. In quarry drilling, where annular velocities can be accurately determined, an annular velocity of 3,000 ft/min of standard air is required for best results in rocks having approximately the same density as those commonly penetrated in drilling oil or gas wells'. Although this standard air velocity has proven satisfactory for quarry drilling, some oil and gas well drilling operators believe that an equivalent annular velocity of more than 4,000 ft/min is required; others believe that as little as 2,000 ft/min . is sufficient. Much of this disagreement results from determining the required circulation rates with methods which fail to incorporate the drilled solids in an equation which is applicable to vertical flow. Hughes Tool Co. Bulletins No. 23' and 23-A3 present data for determining circulation rates based on the Weymouth formula. These data do not include the drilling rate as a parameter and, therefore, neglect the effect of the solids being transported up the annulus. In spite of this apparent defect and the fact that the Weymouth formula is not applicable to vertical flow, the Hughes data have well served the drilling industry in many areas and are important and timely contributions to the science of air and gas drilling. The Hughes data purposely omit a correction for increasing down-hole temperature. At slow drilling rates this effectively compensates for the use of a formula which is not valid for vertical flow; however, volumes determined by the Hughes method are not sufficient to support rapid drilling rates at moderate and great depths. For example, Phillips Petroleum Co.'s Cauthorn "D" No. l in the Vinegarone field for Val Verde County, Tex., was air drilled from 1,500 to 9,300 ft using a compressor delivering 1,400 cu ft/min. The 8 3/4-in hole was drilled with 5-in. drill pipe, and drilling rates as high as 90 ft/hr were obtained between 7,000 and 9,300 ft. No water or caving hole was encountered. At 7,728 ft it was necessary to wash-out 60 ft of cuttings to reach bottom after a trip to change bits. At 8,130 ft a twist-off occurred and the drill col-lars were stuck in drill cuttings. These difficulties indicate that the 1,400 cu ft/min of air was not sufficient to keep the hole clean. Hughes data indicates that 1,180 cu ft/min is sufficient to produce an annular ve-

Jan 1, 1958

By N. L. Muench, J. S. Osba

Research conducted previously has demonstrated that spectral analysis of gamma radiation from the naturally radioactive elements present in earth materials permits detervination of the relative concentrations of these elements. This research suggested that spectral analysis of gamma radiation resulting from neutron bombardment of elements not nor-mally radioactive might serve to identify these non-radioactive elements, and might permit their quantitative determination. To investigate this possibility, laboratory experiments were conducted in which various earth materials were subjected to bombardment by neutrons from a polonium-beryllium source, and in which the spectra of the resultant gamma radiation were analyzed. The geometry of the lab-ortory system was designed to simulate wellbore conditions. The laboratory work demonstrated that some elements not only can be identified with relative ease, but also can be determined quantitatively. This finding indicates that the use of an intense source of more energetic neutrons may lead to the identification and measurement of additional elements of interest by means of induced nuclear reactions. INTRODUCTION In recent years the applications of nuclear physics to the producing branch of the petroleum industry have become increasingly numerous. One significant development, an outgrowth of nuclear science which is of potential importance in well logging, has been the analysis of gamma-ray spectra of naturally radioactive elements in earth strata. The work of Brannon and Osoba1 has demonstrated that presently available equipment and techniques may be used to determine the relative concentration of thorium, potassium, and uranium in underground strata by means of gamma-ray spectral analysis. Success of the research on spectral analysis of naturally radioactive elements suggested that spectral analysis of induced radioactivity might serve to identify, and perhaps measure quantitatively, those elements which normally are not radioactive, but which become radioactive on neutron bombardment. It was to investigate this possibility that the research described in the following sections was undertaken. THEORY OF INDUCED NUCLEAR REACTIONS Of fundamental importance is the fact that an element, when bom- barded with neutrons, emits gamma rays of energies characteristic of that element. Therefore, in theory, an element may be identified by analysis of the energy spectrum of the neutron-induced gamma radiation. If a neutron impinges upon the nucleus of an atom, any one of several reactions may occur. For identification of elements in earth formations the more important are listed below: 1. The neutron may be elastically scattered, as in a collision between two billiard balls. In this case the total kinetic energy is conserved, and no nuclear radiation is emitted. 2. The neutron may be inelast-ically scattered, as in a collision between two automobiles in which case the total kinetic energy is not conserved. The lost kinetic energy reappears in the form of gamma radiation. 3. The neutron may be captured, in which case the neutron becomes a part of the target nucleus, and a gamma ray is emitted. For example, if the target nucleus is H1, the pro-duced nucleus will be H3, and gamma radiation of a particular energy will be emitted. 4. The neutron may produce nuclear fission, or may enter into miscellaneous reactions which result in the emission of

Jan 1, 1958

By Joseph J. Becker

RECENTLY the "oriented growth" hypothesis of recrystallization textures has been receiving considerable attention. According to this view, "whenever a new generation of grains is growing in a highly oriented matrix . . . one may assume . . . that from among available nuclei of a great variety of orientations those with suitable orientation relationship with respect to the matrix have by far the highest rate of growth (oriented growth) and will, therefore, predominate."' This statement includes primary recrystallization of single crystals and of polycrystalline materials showing strong deformation textures as particular cases. While the phenomenon of oriented growth undoubtedly does operate, and may be of importance in coarsening or secondary recrystallization, the writer feels that its extension to primary recrystallization is a different matter. Several aspects of this phenomenon may be pointed out which are difficult to rationalize on the basis of oriented growth. In recrystallizing deformed single crystals of alpha brass, Maddin, Mathewson, and Hibbard2 found that the twin composition planes of the recrystallized grains were parallel to the three operative slip planes they observed, and not to the fourth octahedral plane. The writer's current work seems to indicate further that when only one or two slip systems can be seen to operate, the recrystallized grains are aligned only with those slip planes actually observed. This behavior could hardly be accounted for by oriented growth, because on the latter basis the recrystallized texture of a deformed single crystal should certainly have the same symmetry as the crystal itself. Growth rates could not be expected to distinguish between crystallogra- phically equivalent directions, unless the presence of a visible slip system vastly increases the growth rate in the appropriate direction. This seems unlikely. These relationships were observed by the writer only when considerable care had been exercised before annealing to etch away the effects of cutting out the centers of tensile specimens with a jeweler's saw and to etch off the ends of compression specimens. When these.precautions were not taken, nu-cleation inevitably appeared to occur at the saw cuts or at the ends, and the resulting orientations never showed a [111] rotation but appeared quite random. The provision of many nuclei of many orientations did not enhance the correlation, but destroyed it. Recrystallization textures are sometimes strongly dependent on annealing temperature, which would imply that the anisotropy of growth rates is a suddenly varying function of temperature. This might be regarded as unlikely. Recrystallization textures can be strongly dependent on the degree of deformation. If textures are to be explained by selective growth from among nuclei of all orientations, it is difficult to see how the recrystallization process could have any dependence whatever on the manner or degree of deformation. It is felt that the above points should be considered before the oriented growth hypothesis is applied to primary recrystallization, with the necessary complete divorce of the mechanism of recrystallization from the details of the deformation process. References 1P. A. Beck and H. Hu: Reply to discussion of their paper on Recrystallization Texture and Coarsening Texture in High Purity Aluminum. Trans. AIME, 188, 1057; Journal oF Metals (Aug. 1950) TP 29083. 'R. Maddin, C. H. Mathewson, and W. R. Hibbard, Jr.: The Origin of Annealing Twins in Brass. Trans. AIME, 185, 655; Journal of Metals (Sept. 1949) TP 26763.

Jan 1, 1952

By I. L. Dillamore

A purely geomentrical analysis based on oriented-growth relationships is presented to derive annealing-texture orientations in bcc metals from their- known deformation textures. The analysis takes as its starting point a description of- the bcc deformation texture and follows previous work on fcc metals in considering pvobable nurleation sites for recrystallization and the textural limitations on grains growing into a deformed matrix. The analy-sis accounts for the prominent and the minor coinponents of the annealing textures formed from two the deformation textures and can account for the ob-sem:ed temperature dependence of the annealing texture of bcc metals. THERE have been a number of investigations of annealing textures in bcc metals but few attempts to relate these textures to the deformation textures. This has been largely due to the lack of definition of both annealing and deformation textures, neither of which shows sharply defined orientations. It is, however, necessary to get a better understanding of primary recrystallization textures in bcc metals in view of increasingly exacting demands upon the quality of steel sheet for drawing purposes and as a necessary step towards the control of textures through processing. An analysis is presented here which relates annealing textures to deformation texture, by a purely geometrical method. This takes as its basis the oriented-growth theory of recrystallization and makes some reasonable assumptions regarding the make-up of bcc deformation textures and the limitations on growth relationships in bcc metals. Detailed information on this latter point is not available at the present time, and the present analysis may need to be streamlined or extended when such information is at hand. It is felt, however, that despite these limitations the analysis provides useful results and a valuable aid towards understanding the effect of processing variables. 1) BCC ROLLING TEXTURES Different workers have used a variety of descriptions for the texture developed in bcc metals by rolling. For the present purpose it will be assumed that two different deformation textures can be obtained: 1) a texture containing a major (112)[li0] component and a minor (001)[1i0] component for which increasing deformation causes the (001)[li0] component to increase at the expense of the (112)[li0] component, as suggested by Dillamore and ~oberts' (this is the texture predicted to arise starting from randomly oriented material); 2) a t~xture containing the above components and (111)[110] and (ii1)[112] components. This texture could arise from a material with an initial (110)[001] or (iil)[112] texture. It is well-known that the (ll0)[001] orientation rotates to (ii1)[112]that on roll-

Jan 1, 1965

By S. J. Rothman, J. J. Hines, D. Rokop, R. Bastar

Self-diffusion has been measured along each principal axis of mosaic-structured and relatively perfect a uvaniuln single crystals. The anisotropy reported before,' D[loo] = D[001] » D[010 , has been confirmed. and is shown to represent volume diffusion. Diffusion along the dislocations in the imperfect crystals increases the measured value of D significantly without changingr either the shapes of the penetvation plots or the anisotropy. SINCE a uranium is orthorhombic, the diffusion coefficients along the principal crystallographic axes need not be equal. A previous measurement of self-diffusion in three mosaic-structured a uranium single crystals1 showed that Dil00| =D[001 >>D[010 This result was deduced from penetration plots similar to those in Fig. 1. That is, the plots for diffusion along [loo] and [001] were the straight lines expected from the solution of the diffusion equation for the boundary and initial conditions of the experiment, while the plot for diffusion along [010] was curved so that the part near X = 0 had a much steeper slope than the straight lines did. The observed anisotropy could have been due either to volume diffusion or to diffusion along the very large number of dislocations in such crystals, according to the model proposed by aart.' The authors of Ref. 1 argued that the latter possibility was unlikely, but did not exclude it. To settle the question, a simultaneous measurement of self-diffusion in mosaic-structured and mosaic-free crystals was carried out. This paper reports the results, as well as a measurement of the temperature dependence of self-diffusion in a uranium. EXPERIMENTAL The single crystals of a uranium used in this experiment are listed in Table I, together with other experimental details. '(Mosaic structured" here means crystals grown by solid-state phase change.3 The Laue spots from such crystals spread over about 6 deg of arc, which indicates that the density of dislocations is very large. "Perfect" crystals are ones grown by Fisher's grain-coarsening tehnique; the Laue spots from these are quite sharp,4 which shows that the dislocation density in these crystals is much lower. All of the crystals were made from high-purity uranium; a typical analysis is given in Ref. 1. The actual diffusion directions were within a few degrees of the nominal. The thin layer-sectioning method was used. The experimental techniques were similar to those described in Ref. 1, except the sectioning. Crystals Za, 2b, 2c, 4a, 4b, and 4c were sectioned on a lathe. Crystals 3a, 3b, and 3c were sectioned by grinding on glass plates, with 1 p diamond powder in butyl alcohol as the abrasive. The use of glass plates eliminated the crowning noted in Ref. 1, and the use of butyl alcohol as a lubricant simplified the chemical processing of the sections. Material from the sides of these three crystals was removed by spark machining before sectioning. The sectioning of crystals 4a and 4c was botched. A small cylinder of metal was extruded from the center of crystal 4a while turning off material from the side of the sample. Crystal 4c was misaligned by 2.1 x 10"3 cm because the dial gage jammed during the alignment. Notwithstanding these errors, useful data were still obtained from these crystals. The points

Jan 1, 1967

By Allen Rogers

TWENTY-FIVE DOLLARS for nothing at all except a sheepskin. That to me is the effect of the New York State law for registration of engineers and the same may be said of any of the state licensing laws. Of course, if one has to practice in more than one state, he must pay a more or less equal amount for every state he works in; and yet there has been little effective protest against these laws. It would seem that the spirit which animated the Boston Tea Party is non-existent amongst engineers. Undoubtedly a good many consider, through their failure to understand the law, that the matter does not affect them. In New York State it is provided that "any person practicing or offering to practice profes-sional engineering or land surveying . . . shall be licensed as hereinafter provided." To quote further from the law: "A person practices professional engi-neering . . . who holds himself out as able to do, or who does, the work that an engineer does . . . " The cunning of the wording of this article can only be appreciated by considering that anyone calling himself an engineer falls within the definition; its liberal inter-pretation (I have not quoted the whole of it) would embrace many who do not consider themselves engi-neers. The state authorities may not construe it to include such individuals; indeed, they may possibly consider it inexpedient to extend it to include engineers of subordinate grade, but the possibility is always there and, even though an engineer be of the grade of assis-tant, he may at any time be called upon to substitute for his principal in responsible charge of the work. It is therefore clear that anyone calling himself engineer and practicing engineering must, for his own protection, apply for registration or run the risk of violating the law. Now, what is the sense of all this? We have done very well without such restrictions on the means of gaining our livelihood. If one only stops to think, there is hardly a minute of his modern existence when he is not dependent for his safety on the engineering by engineers of yesterday or today. How often is one in jeopardy through failure of engineering works, work done under the supervision of those same engineers? If all of us had to wait for our ends by such means, our average life would probably be some thousands of years. Where, then, is the point to the object declared in all these laws that the need for licensing is "to safeguard life, health and property?" Bosh!

Jan 4, 1923

By Robert H. Hafner, Irvin R. Kramer, Stewart L. Toleman

IN his paper on the calculation of hardenability from chemical composition, Grossmann1 discussed the effect of most of the alloying elements used commercially. The purpose of the work reported in this paper was to determine the effect of several other elements on hardenability-arsenic, antimony, beryllium, cobalt, columbium, germanium, tellurium, tin, aluminum, and titanium-and to extend the range of composition of some of the elements studied by , Grossmann-chromium, copper, manganese, molybdenum, nickel and silicon. EXPERIMENTAL METHODS To determine the effect on hardenability, suitable amounts of the alloying elements were added to experimental heats and the hardenability determined by means of end-quenched hardenability specimens. The steels were melted in a high-frequency induction furnace with a basic crucible, using ingot iron as a base for some of the heats and S.A.E. 1015 for others. The alloying additions were made as ferroalloys or as metal, depending on the ' alloying element. Hundred-pound heats were split and poured into square, tapered, cast-iron ingot molds with hot tops. Aluminum was not used as a deoxidizer in most of the heats. The ingots were homogenized for 12 hr. at 1260°C. (2300°F.) , and forged into rounds of 1 ½ in. diameter. These bars were normalized twice from 840°C. (1550°F.) before machining into Jominy bars. The composition of the steels was deter- [ ] mined in most cases by samples taken from the end-quench hardenability specimen. As suggested by crafts,2acid-soluble

Jan 1, 1943

By John G. Simmons

A tutorial account of the tunnel effect between metal electrodes separated by a thin insulating film is presented. Energy diagrams of metal-insulator -metal sandwiches are briefly discussed, and the isothermal and thermal J-V characteristics for symmetric and asymmetric tunnel junctions are derived from a generalized expression. Experimental data from tunnel junctions are presented, and it is shown how, correlation between theory and experiment permits a determination of some of the oxide properties. Finally, the barrier heights in AT-Al2O3-A1 junctions determined by various inr3estigators are discussed. The object of this paper is to give a tutorial account of the electric-tunnel effect between metal electrodes separated by a thin insulating film and to illustrate its utility in the study of metal-oxide interfaces. This paper will emphasize the theoretical aspects of the electric-tunnel effect: however, a brief account of the more recent experimental work will be presented. A more comprehensive experimental study of the tunnel effect will be presented in the following paper by Drs. Pollack and Morris, see p. 497. We will open with a discussion of the energy diagrams for metal-insulator-metal junctions and what we mean by the electric-tunnel effect. Following this is an account of the theoretical studies of Sommerfeld and Bethe, and Holm, and the recently reported calculations on symmetric and asymmetric junctions using the generalized formula. The theoretical presentation is concluded with calculations on the temperature dependence of the tunnel J-V characteristic. In the experimental section, it is shown how barrier heights and thicknesses are determined by comparing the experimental data with the theory. Finally, the results of various investigators on the determination of the barrier heights in Al-Al2O,-A1 systems are discussed. I) POTENTIAL BARRIERS BETWEEN CLOSELY SPACED ELECTRODES Since it is necessary to supply energy to a metal in order to observe electron emission from its surface, it is evident that the potential energy of an electron within a metal is lower than that of an electron at rest outside the metal. It follows, then, that the electron must undergo a change in potential as it crosses the metal-vacuum interface. In the Sommerfeld1 free-electron theory of metals it is assumed that the free electrons, the electrons responsible for the electrical characteristics of metals, move in a constant potential environment in the metal, and are contained within the metal by a potential barrier at the metal-vacuum interface. It will be evident that the idea of a constant potential environment is a very idealized model, since the potential energy of an electron is influenced by all of the atoms and the other electrons within the metal; however, its use is justified by the many excellent results it gives.2 Fig. l (a) is the energy diagram of the model envisaged by Sommerfeld; the metal is represented by a potential-energy well of depth V,; the vacuum level represents the energy of an electron at rest outside the metal. At 0°K the electrons, which exist in pairs in discrete energy levels, fill up the well to an energy ?, the Fermi level. The distance, Vo - ?, from the Fermi level to the vacuum level is known as the work function of the metal, and represents the minimum energy required to free electrons from the interior of the metal at 0°K.

Jan 1, 1965

By J. J. Cosgrove, J. E. Warren

A general model which approximates the effect of cross- flow has been developed to give a practical method for predicting the waterflood behavior of a stratified reservoir. The model is based on a modification of Dietz's theory and allows for variations in both the permeability and hydrocarbon pore volume. In the particular cases considered, it is assumed that the permeability can be characterized by a log-normal distribution and the hydrocarbon pore volume by a normal distribution. A simple graphical method which enables the practicing engineer to predict the behavior of a stratified system is presented The results obtained by the proposed method are compared with those obtained by the Dykstra-Parsons method. As a result of this study the following conclusions have been drawn: (1) The effect of cross-flow in a stratified system can be appreciable, particularly at very favorable or very unfavorable mobility ratios; (2) Under normal conditions, the effect of variations in the hydrocarbon pore volume can be neglected; and (3) The failure to use all of the available permeability data can lead to large errors in the prediction of the behavior of a stratified reservoir. INTRODUCTION Various methodshavebeenproposedto characterize and to predict the waterflood behavior of a stratified reservoir. Most of the methods assume that the reservoir is composed of discrete homogeneous continuous layers. With this model, the degree of stratification can be measured by several parameters based on core-analysis data. Among these are the Lorenz coefficient1 and the variation of a log-normal permeability distribution? The behavior of stratified systems is usually predicted by the Stiles, Dykstra-Parsons method or some modification of these. In both of these methods the reservoir is divided into discrete homogeneous layers with no cross-flow between layers. In the Stiles method the mobility ratio is assumed to be equal to unity while in the Dykstra-Parsons method it is allowed to take on any value. Other predictive methods have been proposed; method allows for cross-flow between the beds and a method by Schmalz and Rahme6 correlate.s the recovery directly with the Lorenz coefficient. In this new approach, which is essentially a continuous analog of Hiatt's method, the effects of both mobility ratio and cross-flow between the beds have been included. It is assumed that the permeability can be represented by a log-normal distribution and the hydrocarbon pore volume or porosity by a normal distribution. These types of distributions have been observed by several authors, 1,2,4 and most field data seem to confirm their observations; e.g., if these distributions are assumed and there is a 1:l correspondence between porosity and permeability samples, the commonly encountered linear relationship between porosity and the log of permeability is obtained. Since, in many field cases the permeability and poro sity data are truncated or cut-off at predetermined upper and/or lower values, the effect of discarding part of the data was investigated with the proposed method. A better technique for truncating the data is suggested. THEORY In the derivation of the method to be described in this paper the following assumptions are made: 1. Capillary forces are negligible per se; their effects are only manifest in the relative permeability curves. 2. The fluids are immiscible, incompressible and homogeneous. 3. The reservoir is horizontal and uniformly thick; it is initially liquid saturated i.e., connate water and oil. 4. The reservoir is composed of discrete layers, each having its own permeability, porosity and connate water saturation; each layer is homogeneous,

Jan 1, 1965

By Charles Janin

ONE of the most interesting features of the world's platinum situation has been the steady increase of Russian production, which had dropped to 11,000 oz. in 1920, but increased to 92,000 oz. in 1926, and to probably over 100,000 oz. for 1927. It is ex-pected that Russian production of platinum will, be-fore long, closely equal its pre-war production, or approximately 200,000 oz. annually. The world production before the war was around 250,000 oz.; that for 1925 has been estimated at 160,000 oz., and for 1926 probably 170,000 oz. The consump-tion of platinum has, however, decreased. The esti-mate of the International Selling Agency was a de-mand of 130,000 oz. new platinum against a normal pre-war demand of over 200,000 oz. The high price of platinum during the war gave an added impetus to the search for substitutes for the metal, and sev-eral were developed that are now used extensively in place of platinum. The demand for platinum for high-class jewelry, however, was not greatly affected by the high prices, but "white" gold did replace platinum in the cheaper jewelry. Colombia is the most important producer of plati-num, next to Russia, and the production has increased from around 10,000 oz. pre-war production to 55,000 oz. or more in 1927. In 1924 important discoveries of platinum were made in South Africa. Prior to these discoveries practically all platinum was recovered from alluvial deposits, and the South African opera-tions are first to work an ore profitably for the pri-mary recovery of platinum. A number of companies were formed to develop these deposits, but only a few made any real progress. Total production for 1926 was about 5000 oz. The United States production is unimportant; that in Canada has increased to around 9000 oz., principally as a by-product in nickel-copper ores.

Jan 5, 1928

By V. C. Williams

Some of the physical, chemical, and electrical processes for conversion of saline water to potable or industrial water are economically surveyed from an engineering viewpoint. Since all these processes require energy for drive and equipment for containment, the correlative economic factors are developed which indicate directive influences in the choice of particular regional processes. The supply of natural waters and its distance also affect decision. Any one process will probably not prove dominant in the field because auxiliary considerations such as the saline water source; types and continuing availability of fuel; electric power use or recovery; area economic status and advancement; and the political pressures of population, group demands, and land use tend equivocally to obscure capital and operation cost decisions. Basic engineering considerations, data, and economic factors are presented to assist in the direction of these decisions. An exploding world population, increasing industrialization, advancing standards of living, and the desire of less-privileged nations for betterment focus attention sharply on a major problem: water. *19 Up to now, in retrospect, people have had it relatively easy in the handling of this problem. All the better dams in the most advantageous sites, the better aquifers, the shortest aqueducts have been built. In another phase of the problem, concern is evident that wastes cannot indefinitely be disposed of merely by keeping them dilute and discharging them promiscuously. 7-9 And, perhaps, as past civilizations have done,l5 water, watersheds, streams, and irrigation may have been mismanaged or, at the least, not adequately studied.3,5,36,37 In this last is perhaps the core of the problem. As Gross states, "Ignorance and too often, indifference are contributing factors. Archaeology and theology both furnish ample testimony to the existence of rich lands where deserts now stand; it was man who ravaged his land. Unless education is a companion to water development, development might as well be forgotten. But without water, there is no beginning."13 The U.S. is showing increasing concern about its water for predictions are that by 1980 the daily withdrawals will be 494 billion gal, a figure nearly equal to the dependable supply.Is This is based on a conservative projected population of 230 million. The major categories of withdrawals are: To make available this per capita average of 2150 gal per day will require an expenditure of $219 billion over the next 20 years. The U.S. is not alone in this concern. The United Nations shows as arid zones of the world: all of Africa north of the equator and south of the 20's parallel; all of the Arabian peninsula; all of the middle east and Iran, Iraq, Pakistan, Afghanistan, northern and central India; a great band about 1000 miles wide along the 40'~ parallel from the Caspian Sea east across Russia through China to the Pacific Ocean; all of Australia except the coastal plain; the Caribbean Islands; the western nations of South America; and the western third of the United States and of Mexico. With one quarter of the earth's 57,500,000 sq miles of land thus suffering from lack of good water, increasing attention goes to the treatment of brackish and sea waters. The U.S. has been a leader in this field4,12, 16123,24 through its Office of Saline Water in the Dept. of Interior because even now some of its cities and regions are short of potable water. 11j'7,M Industrial water is also of vital concern as a result of ever higher industrialization1,14122 Other nations, among them JaPan, Israel,13188 Germany, Union of South Africa, Australia, Netherlands, France, Yugoslavia, Russia, and groups such as the Organization for European Economic Cooperation (OEEC)' are also diligent. The objective is low cost water, which means that both technology and economics have prominent roles in saline water conversion processes. TECHNOLOGY: SALINE WATER CONVERSION A number of reviews of methods have been made, principally by staff members of the Office of Saline Water (U.S. Dept. of Interior). Jenkins,31'32 Gillam,34p

Jan 1, 1962

By J. P. Zannaras

If we assume that testing of the model started at time C, that time t2 was the instant at which the elastic limit of the material was passed at the points of the maximum stress, and that at time t3 the failure of the model was completed as shown in the typical photograph (Fig. 1), then actually the photograph shows the final results of what took place between time t2 and t3. By the principle of similitude all conclusions drawn from the behavior of the model were applicable and valid for actual mine roofs up to the time t, after time t, motions and friction came into play during the destruction of the model. The events between t2 and t3 and the photograph itself are not representative of the events expected in an actual mine roof unless corrections imposed by the principle of similitude are made.

Dec 1, 1956

By Odmund Ljone

FAR north of the Arctic Circle is a totally industrial community which until 1945 could not boast a single specimen of the rat family, and where today you will be awarded a bottle of fine cognac for every rat-dead or alive. Amazing but true, the spot is Longyear City, the Norwegian mining town on the arctic island of Spitzbergen. Perhaps you have also heard of the town built on soil that never thaws, where huge blocks of ice must be melted to fill the city's fresh water reservoirs, and where the Far North dictates a way of life all its own. Here, coal is king and men must work hard for their "black gold." Spitzbergen is a rough, tough piece of Norway, made up of a half dozen isolated islands between 74 and 81 degrees north latitude. Covering twice the area of Belgium, they are home to

Jan 1, 1948

By S. S. Cole, H. Sigurdson

The melting points of mixtures of titanium dioxide and other titanates have been reported to a limited extent as binary systems and some results have been reported in conjunction with silicon dioxide. The limited data indicated that a low melting zone might exist in a ternary or quarternary system of CaO-MgO-TiO2-Al2O3, since the eutectics reported in the binary systems of MgO.TiO2-TiO2, Al2O3TiO2-TiO2 and CaO.TiO2-TiO2 were of about equivalent composition of TiO2. The importance of a low melting region with a high titanium oxide value in the developing of high titanium slags is fully appreciated by metallurgists. A comprehensive study was undertaken to establish basic information on low melting titanate mixtures. Compounds in the System CaO-MgO-TiO2 -Al2O3 Preparation of the titanates of CaO, MgO and Al2O3 confirmed reported data that the following compounds could be formed under oxidizing conditions in solid state reactions: CaO.TiO2, 2MgO.TiO2, MgO.TiO2, MgO-2TiO2 and Al2O3.TiO2. Under oxidizing conditions it was not possible to react MgO with TiO2 in mol ratios higher than 1:2 without having unreacted TiO2 in the product, nor was it possible to form calcium or aluminum titanates with a higher mol ratio of CaO and A12O3 to TiO2 than 1:1. By fusing mixtures of Al2O3-TiO2 and MgO-2TiO2 together a series of solid solution products were obtained, which showed an MgO-2TiO2 X ray diffraction pattern shifted to smaller inter-planar spacings. Range of Investigation Data in the literature1 indicated that these titanates had melting points which ranged from 1645 to 1860°C. Since the purpose of the study was primarily to provide useful data for smelting titaniferous ores, the work was restricted to the zone of the system which would include the crystalline phases present in the slags. The explored limits were bounded by CaO.-TiO2-MgO.TiO2-TiO2in the base plane. The system was extended to a fourth component Al2O3-TiO2 since many titaniferous ores contain appreciable amounts of A12O3. In the quarternary system CaO-TiO2-MgOTiO2-TiO2-Al2O3TiO2, a tetrahedron was used to represent graphically the components, with one component at each point of the tetrahedron. In the base plane, mixtures were pre- pared to represent fairly uniform changes of composition over the desired range expressed on a mol percent basis. Al2O3-TiO2 was brought into the system in increments of 10 mol pct up to 40 pct. Mixtures were then made up for each of the Al2O3-TiO2 planes. The ranges employed were then represented by five planes cutting the tetrahedron at 10 mol pct Al2O3-TiO2 intervals. Choice of Equipment Although it was necessary for all smelting work to be done in a strongly reducing atmosphere, it was decided that all melting point determinations should be done under oxidizing conditions. This decision was prompted by the fact that TiO2 reduced to lower oxides in a reducing atmosphere with consequent changes in melting points. The use of a micropyrometer and a platinum strip furnace for work of this type is adequately described in the literature.2 With modifications, equipment was selected which provided a fairly rapid method of determining melting points of refractory oxides. The final assembly, which was used, consisted of a platinum strip furnace and a Leeds and Northrup disappearing filament optical pyrometer attached to a special telescope which magnified the sample about 20 diam. The furnace assembly consisted of a platinum strip 0.005 X 0.3 X 2.2 in. mounted on brass posts on a refractory base. This was enclosed in a black steel shell which had a 2-in. opening at the top for purposes of sighting the telescope. The platinum strip was in series with two 0.04 ohm nichrome resistors connected to the secondary of a 2 kw transformer which supplied 17 volts. The current to the primary was varied

Jan 1, 1950

By Henry J. Kaiser

A few months ago I had the honor of addressing the Society of Mining Engineers annual banquet in Sun Francisco. I have since been asked to amplify some of the remarks I made at that time concerning the management policies of the Kaiser organization and various aspects of our corporate thinking. This is a difficult task for an insider like myself. I look at the different companies, and the men who run them, and it is hard to think of these men in terms of policy or procedure. Actually I prefer the term management philosophy to either policy or procedure. My father, Henry J. Kaiser, is not only the founder but the guiding spirit of our organization. His philosophy, and in turn that of the organization, centers around two concepts, service and accomplishment.

Jan 1, 1960