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By D. O. Hobson

Zirconium single crystals of various specific orientations were fabricated by rolling or drawing. The resulting textures were determined and are discussed with respect to the deformation modes that produced them. The crystals deformed in a predictable manner by combinations of up to third-order twinning with three twinning modes and by slip. Twinning was found to play a major role in initial texture formation. Texture changes produced by slip occurred only at the higher reductions. The twinning sequences that produced each intensity peak during the initial reductions could be identified. Schmid factor criteria were found useful in predicting which deformation modes to expect for each crystal orientation and fabrication procedure. The possible application of these data to poly-crystalline material is discussed. PREFERRED orientation or texture has a significant effect on the properties of most materials, causing anisotropy in fabricated cubic metals and enhancing the natural anisotropy of noncubic metals. This study evaluates the effects of several fabrication methods on the textures formed from specific starting orientations of zirconium single crystals and, it is hoped, gives an insight into the effects of the same operations on poly-crystalline material. BACKGROUND In fcc and bcc metals, texture changes take place by gradual lattice rotations caused by the operation of one or more slip systems. Deformation twinning plays an insignificant role in the deformation of such metals. In zirconium and its alloys, however, and in many other hep metals the ability to twin allows very rapid texture changes to be made with very small amounts of deformation. The deformation systems found in zirconium and its alloys are prism slip and three twinning modes.1 Slip occurs on the {1010}< 1120) system. There is little or no appreciable basal slip in zirconium. The twinning planes, illustrated in Fig. 1, are {1012}, {ll2l}, and {1122}. Two twinning modes, the {1012} and the {ll2l} operate for a tensile stress along the basal pole. A compressive stress parallel to the basal pole is required for {ll22} twinning. These twinning operations cause a 35- to 85-deg reorientation of the basal pole. The {1012} twin is the predominant tensile twin at room temperature. The twinning shears, S, are shown in the figure. A criterion for predicting which deformation system will operate when a grain is subjected to a known stress state is the Schmid (orientation) factor. This factor gives the fraction of the applied stress that computer program was written2 to calculate the Schmid factors for the four deformation modes in zirconium. It assumed three orthogonal stress axes and considered ninety-one different orientations of the basal pole in one octant of this stress space. At each basal pole position the Schmid factors were calculated for seven positions of rotation at 10-deg increments of the unit cell about the basal pole. Schmid factors were determined for a total of 637 orientations and for twenty-four deformation systems in each orientation. The program listed the Schmid factors for uniaxial stress parallel to each axis and, to approximate rolling, or-thonormal biaxial stress was also considered. Fig. 2 shows the range of orientations over which the various types of deformation would tend to predominate in biaxial plane strain with the stresses, equal magnitude. The exact boundary position between regions of different deformation modes depends, however, on the relative values of the critical shear stress for each deformation mode. Fig. 2 is drawn on the assumption that they are equal and it therefore may be only approximately correct. It is also recognized that the biaxial stress analysis may not be applicable in certain crystal orientations. EXPERIMENTAL PROCEDURE Single crystals of zone-refined zirconium, produced by Wilson of this Laboratory,3 were electrical-discharge-machined to form specimens for rolling, tube-drawing, and rod-drawing studies. Specimens were rolled at room temperature on 2-|--in.-diam hand-powered rolls from three different starting orientations: 1) the basal plane parallel to the rolling plane and the [1120] in the rolling direction, (0001)[ll20]; 2) the (1120) plane parallel to the rolling plane and the basal pole in the rolling direction, (1120)[0001]; and 3)_the (1120) plane parallel to the rolling plane and the [1100] in the rolling direction, (1120)[ll00]. Drawing specimens were cut with the [0001] direction as the drawing direction in the tube blank and [1120] as the drawing direction in the rod specimen. The drawing

Jan 1, 1969

By H. R. Crawford, P. B. Crawford, A. F. Tragesser

A method has been developed to calculate wellbore temperatures during mud circulation and the actual cementing operation to aid in the design of cement slurries. The method agrees within 10F with previously measured values. The calculation technique provides temperatures, as functions of time, at varying depths in both the casing and annulus. The technique also provides this information if a relatively cool cement slurry is pumped into the well immediately following circulation of hot mud. Circulating bottom hole temperatures of brine and a bentonite mud were measured. INTRODUCTION As wells are drilled deeper, greater demands are being made on all phases of the industry, and new technology has been developed to provide satisfactory well completions. However, little or no work has been conducted on accurately determining bottom-hole, static and circulating temperatures.. In designing a cement slurry, such factors as density, fluid loss control, viscosity, deterioration from ternperature, compressive strength and pumping time must be considered. Individual well conditions often make it necessary to include still other factors. Pumping time is a primary consideration and, as wells are drilled deeper, encountering higher bottom-hole temperatures, this property becomes even more important. Cement slurries must be designed with sufficient pumping time to provide safe placement in the well; however, the slurry cannot be overly retarded as this will prevent the development of satisfactory compressive strength. The pumping time of a specific cement is currently obtained by subjecting the cement to simulated conditions of temperature and pressure. A reasonably accurate bottom-hole pressure may be obtained by considering hydrostatic heads of fluids, friction pressure and wellhead pressures. However, accurately determining bottom-hole temperatures is much more difficult. Bottom-hole static temperatures are estimated by considering several sources of information, including logging temperatures, published temperature gradient maps and field experience. This information is usually questionable due to disagreement of data from the various sources. Temperature gradient maps were constructed based on temperatures recorded many years ago while running bottom-hole pressure tests. These thermal gradients then represent an average of well conditions and cannot always apply to a specific well. Also, logging temperatures may be affected by the time since fluid was last circulated, rate of penetration, circulating rate and many other factors. Therefore, even though logging temperatures are available, the question still exists as to the correction factor that should be applied to obtain an accurate static temperature. After obtaining static bottom-hole temperature, it is then necessary to relate this to circulating temperatures actually encountered by the cement slurry. This is accomplished by selecting a test schedule from the API RP-10B corresponding to the estimated well conditions.&apos; The API-recommended practice for testing oilwell cement provides testing schedules for various well depths and conditions. These schedules are intended to simulate down-hole conditions during cementing. They provide a rate at which both temperature and pressure are increased until the estimated circulating conditions are reached. These testing schedules represent circulating temperatures for an average well and, although there is flexibility in choosing the test schedule that most accurately simulates the temperature of an individual well, it still is not possible to consider all the well conditions that will affect the bottom-hole temperature. Many factors affect cement temperatures; for example, the length of time a well has remained static prior to running casing and cementing, the circulation time, the temperature of fluids used in cementing, fluid density and flow properties of fluids. The pumping time for a typical retarded cement could vary from 2 to 4 hours with a 10F change in testing temperature. Variations in pumping time are the most critical in highly retarded cements used in deep, hot wells; yet, predicting bottom-hole circulating temperatures is more difficult in these wells. This work was conducted to develop a means of calculating circulating temperatures as a function of well depth, casing and hole size, pumping rate and time, fluid and reservoir physical properties and thermal status of the well. PREVIOUS WORK In 1941 Farris reported on a study to develop information leading to a more practical laboratory evaluation of oilfield cementing mixtures and performance.&apos; It was then recognized that the pressure factor was being neglected,

By John D. Price

COAL blending, in the preparation of coal before coke making, is so commonly practiced as to be almost universal. But the reasons underlying this practice, the benefits resulting from it, and the materials used in blending vary widely. This paper will outline the various phases of the subject and present information which may be correlated with work that has been done elsewhere. It will deal entirely with work done on the high-volatile coking coals of the western part of the United States, special emphasis being given to the coals of Colorado and Utah. A surveyL of the 86 coke plants in active operation in the United States during 1949 indicates that only 9 plants, or 10.5 pct of the total, charged one single rank of coal into their ovens, while the remaining 89.5 pcl made use of blending in some form. This report indicated that of these total plants 5 used straight high-volatile coal, 4 used straight medium-volatile coal, 47 used blends of high and low-vola-tile coals, 25 used blends of high, medium, and low-volatile coals, 2 used blends of high and medium-volatile coals, 3 used blends of medium and low-volatile coals. The fact that certain plants operated on a single kind of coal should not be interpreted to mean that no blending was practiced there, for invariably such plants secure their coal from more than one source and in the interest of uniformity do blend the coals as received. The general term coal blending covers two fields, the first of which is the mechanical mixing of a number of coals to secure uniformity. Often it is found necessary to secure coal for coke production from a number of different mines; these coals, though of the same general type or rank, may differ in their chemical composition or in the physical qualities they impart to coke made from them. Again, it is not unusual to find that coal from different sections of the same mine may show variations in quality. Under such conditions it may be necessary, in the interest of a uniform final product, to introduce a system of blending bins, a bedding yard, or other mechanical methods of securing a uniform mixture. Unfortunately this form of blending has received very little attention up to the present time; it has not received the consideration its value merits. The second type of blending, while also for the purpose of coke improvement, deals more particularly with the use of a blending agent differing in character from the base coal: it is this form of blending that will be discussed here. To consider only the western coals, for blending may be found necessary for other reasons with other coals, blending has been practiced experimentally or commercially under the following conditions: 1—When a single coal or mixture of coals of the same rank does not produce a satisfactory coke. For example, a high-volatile coal when used alone is likely to contract when coked so that a comparatively weak coke is formed. Or, if of very low rank, the coal may be deficient in the necessary bitumens required for good coke production. 2—When a product of some special quality is required, for example, when a plant ordinarily producing blast furnace coke must operate at slow coking rate to produce a high-grade foundry coke. Under this condition the reduced daily production of all products which accompanies slow coking time may be undesirable, and the use of some blending agent to increase the size of coke made at faster coking rates may be necessary. 3—When greater yield of coke or its coproducts is needed. Depending upon economic values of the products it may be found desirable to increase the yield of one or the other. 4—When supply of a particular coal must be used, either to protect reserves of high quality coking coal or to utilize a surplus or inferior product not otherwise usable. Many materials have been used for blending purposes, the exact agent to be used depending both upon the condition to be corrected and the nature of the base coal. No universal blending agent that can

Jan 1, 1954

By J. D. Mote, J. E. Dorn

This investigation was undertaken to study the effects of piledup arrays of dislocations on inducing slip, twinning, and fracturing in magnesium bicrystals. A series of variously oriented bicrystals of magnesium having a vertical grain boundary were prepared and tested in tension. It was found that piled-up arrays of dislocations at the grain boundary could, under appropriate conditions, induce slip, twinning- and cracking. The results that were obtained substantiate, at least qualitatively, the general dislocation mechanism for transmission of strain across grain boundaries and the Petch-Stroh concept of fracturing. WHEREAS single crystals of magnesium generally exhibit extensive deformation, coarse-grained poly-crystalline magnesium at subatmospheric temperatures fractures after a few percent elongation.&apos; Although a small amount of ductility is obtained, several features of this fracturing are characteristic of typical brittle behavior. Over a rather broad temperature range the fracture stress is insensitive to the test temperature and the fracture stress increases linearly with the reciprocal of the square root of the mean grain diameter. The course of fracturing is predominantly intergranular, but small fragments of adjacent grains frequently adhere to the fractured surface.2 The brittle behavior of polycrystalline magnesium is attributable to the limited number of facile deformation mechanisms it exhibits at low temperatures. For a general deformation of a randomly oriented polycrystalline aggregate, each grain must exhibit at least five independent mechanisms of deformation to permit accommodation of the imposed deformation from grain to grain.= Although minor amounts of prismatic slip occur in corners of grains where stress concentrations are known to be high, glide in polycrystalline magnesium at low temperatures takes place almost exclusively by basal slip.&apos; The common type of twinning, which takes place on the (1012) pyramidal planes, can under the most favorable orientations, lead to a. strain of only 6.9 pet; the contribution of twinning to the tensile strain would indeed be much less than this in a randomly oriented polycrystalline aggregate of magnesium. Since the three mechanisms of basal slip are coplanar, they are equivalent to only two independent mechanisms, a number insufficient for a general deformation. Consequently, once the permissible twinning has taken place in conjunction with basal slip, no further plastic deformation is possible because of interference to slip at the boundaries of dissimilarly oriented grains. At this stage brittle fracturing takes place due to high stress concentrations at the juncture of slip bands with the grain boundaries; the predominance of intergranular fracturing in magnesium, in preference to transcrystalline fracturing which is prevalent in zinc, has not yet been rationalized. A more atomistic description of the plastic behavior and fracture characteristics of magnesium follows from the analyses made by stroh4 on the stresses induced by piledup arrays of dislocations. Slip first takes place by dislocation motion in the most favorably oriented grains. As the dislocations approach the boundary of a dissimilarly oriented adjacent grain they begin to form an array of dislocations with its attendant stress field. Piledup arrays of screw and edge dislocations introduce high localized shear stresses at the spur of the array; piledup arrays of edge dislocations also induce high tensile stresses localized in the vicinity of the grain boundary. Whereas the shear stresses can induce slip to take place, the tensile stresses, if sufficiently high, can cause fracturing. The localized shear stress will be relieved if sufficient numbers of mechanisms of deformation become operative in the original and the adjacent grain to permit accommodation of the dislocations in the grain boundary. In this event a ductile behavior will be obtained. But if the number of deformation mechanisms is insufficient for complete migration of dislocation arrays into the grain boundary, the tensile stresses due to the edge components of piledup dislocation arrays will continue to increase with increasing applied stress until fracturing takes place. Whereas face-centered-cubic metals have a sufficient number of mechanisms of slip for accommodation of dislocations in their grain boundaries to exhibit ductile behavior, hexagonal-close-packed metals, in general, do not. Consequently, hexagonal-close-packed metals are usually brittle except when conditions such as alloying or temperature permit facile slip by a number of mechanisms. The arguments presented above suggest that the mechanical behavior of magnesium depends on whether or not dislocation arrays in adjacent grains can enter the grain boundary. When such accommodation is possible, ductile behavior is expected; but when such accommodation is impossible, fracturing will ensue. To further test the validity of these arguments it was considered advisable to study the

Jan 1, 1961

By Y. S. Bonillas

Page I. Introduction.......................... 286 II. Physiography.......................... 286 : 111. Introductory Geology...................... 287 IV. Rocks of the District ...................... 288 (A) Sedimentary Rocks..................... 288 Pinal Schist ........................ 288 Bolsa Quarteite....................... 289 Abrigo Limestone...................... 290 Capping Quartzite..................... 291 Martin Limestone...................... 292 Escabrosa Limestone .................... 295 Naco Limestone....................... 296 Cretaceous Deposits..................... 296 Glance Conglomerate................... 296 Morita. Mural and Cintura Formations........... 297 (B) Igneous Rocks........................297. Pre-Cambrian Granite.................. 297 Pre-Cretaceous Granite Porphyry............. 298 Rhyolite........................301 Other Dikc Rocks.................... 301 V. Structural Geology........................ 304 General Structure of Mule Mountains............. 304 Fault Blocks and Other Divisions............. 304 Igneous Rocks...................... 312 Copper Queen Block..................... 313 Fault Blocks...................... 313 Intrusions....................... 315 Don Luis Block....................... 315 Intrusions and Orebodies................. 316 VI. Geologic History......................... 316 VII. Metamorphism and Mineralization................. 318 General Metamorphism.................... 318

Jan 1, 1917

The following tables showing the output of coal during the year 1913 have been secured y R. H. Morris, of Pocahontas, Alberta, Canada, for the use of the Committee through the kindness of John T. Stirling, Chief Mine-Inspector of Alberta. The principal mining districts are, Crow&apos;s Nest Pass, Calgary, Lethbridge, and Edmonton, the outputs from which were as follows: Tons Crow&apos;s Nest Pass 1,849,435 Calgary...: 627,461 Lethbridge ; 966,020 Edmonton 863,430 Total 4,306,346 Of this quantity there was exported to the United States, principally from the Crow&apos;s Nest Pass district, 138,201 tons of 2,000 lb., that being the ton used throughout the Province. This production consisted of lignite, bituminous coal, anthracite, coking coal and coal used in making. briquettes, as follows: Tons "Lignite coal" (lignitic?) 1,763,225 Bituminous coal 2,374,401 Anthracite coal 168,720 Coking coal 104,012 Coke produced 65,167 Briquettes produced 130,861 The only district in which coke was made is the Crow&apos;s Nest Pass district, and the entire product was consumed in Canada. The total number of persons employed is as follows: Above ground 2,231 Underground 5,837 Total 8,068 The per capita production was as follows: Tons of coal mined per employee 533 Tons of coal mined per underground employee 737

Jan 7, 1914

Raymond Weir Smyth, born Nov. 3, 1888, was the son of Herbert Weir Smyth, professor of Greek Literature at Harvard University. He graduated (A. B.) from Harvard in 1909 and later pursued advanced studies there in chemistry and in metallurgy. He held the position of metallurgist for the American Steel and Wire Co. at Worcester, Mass., and also for the Steel and Tube Co. at Youngstomn, Ohio. For a time he was inspector of munitions for the British Government and stationed at the Railway Steel and Spring Co. at Latrobe, Pa. For a short time, in 1917, he was Inspector of Ordnance for the U. S. Government, and the following year, having entered the U. S. Naval Reserve Force, he was ordered in a similar capacity to the Midvale Steel Co. In September, he removed to the Navy Yard, League Island, Philadelphia, to train for the obligatory minimum of six months&apos; sea duty. There he contracted influenza, which was followed by pneumonia, from which he died, September 27, at the Navy Yard Hospital. Captain Braxton Bigelow* Captain Braxton Bigelow was the son of Major John B. Bigelow, U. S. A., retired, and grandson of the late John Bigelow, author, and Minister to France under President Grant. Captain Bigelow graduated

Jan 1, 1920

By James R. Swaisgood, Ronald E. Versaw

Hundreds of shafts have been sunk in the United States in the past. Most of these have been successful however, in some instances thousands of dollars have been lost due to work stoppage while emergency measures were taken to control unexpected water flows. In cases where it was not possible to control the water, the shafts were completely lost. Many thousands of dollars have also been wasted in overconservative support design for the successful shafts. These "hell for stout" designs were necessary because of the importance of the shaft in the operation of the mine. If there was trouble in the shaft, all underground operations would come to a halt. Over-design was also necessary because no reliable preconstruction investigation methods or rational support design methods were available.

Jan 6, 1974

By J. Wayne Erickson

Hundreds of millions of dollars have been spent to discover or purchase uranium resources that cannot, or should not, be mined with conventional methods if human, natural and financial resources are to be conserved. Three years ago, an industry-supported research stud was initiated to determine whether a safer and more efficient (in terms of cost and environment) uranium mining method could be designed to replace existing techniques. As a result of this study, the "underground in situ" method was conceived and developed to the stage where it is now feasible. This approach involves: (1) sinking a shaft; (2) driving a drift on the ore horizon the length of the ore body; (3) drilling almost-horizontal long holes the width of the ore body; and (4) oxidizing and leaching the uranium drawn from these holes. The method is unique in that the uranium is removed with a minimum of disturbance to the natural hydrology of host or surrounding sands.

Jan 11, 1978

CERTIFICATE OF INCORPORATION [AMENDED Nov 22, 1912, AND JUNE 27, 1919 ] WE the undersigned, being all persons of full age and citizens of the United States, and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 5 of Article I of said law, the existing unincoiporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and file this Certificate for that purpose, and do Certify as follows I That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained II That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council, that the undersigned are all members of said Council as the same was constituted on the 29th day of December, 1904

Jan 1, 1923

By Gerald A. Munson, Fremont F. Clarke

DURING recent years the use of lithium has expanded greatly in industrial, chemical, and metallurgical fields, while at the same time modernized methods of mining and refining lithium have increased production. Technical literature includes many papers describing the geology and mineralogy of lithium deposits. Mining and beneficiating problems, however, have not been thoroughly described. Published reports have failed to emphasize that one of the chief reasons lithium minerals were not extensively mined until recently is the difficulty of beneficiation. Four lithium minerals of pegmatites and the lithium-sodium-phosphate byproduct from the brines at Searles Lake, Calif., have been sources of lithium. Among the pegmatite minerals, only spodu-mene and petaline are known to occur in deposits large enough to support large tonnage operations. Spodumene, a lithium-aluminum-silicate, is the principal lithium mineral mined in the U. S. Lithium Corp. of America, during its rapid development and growth, has successfully employed three different methods of concentration: 1) hand sorting, 2) Heavy Media separation, and 3) froth flotation. Each method, though economic in its sphere, is becoming outdated as extractive techniques improve. The most recent development has taken place at Lithium Corp.&apos;s new operation in North Carolina, where the extractive process yields lithium compounds directly from mined rock without an intervening concentrating step. Until 1954 Lithium Corp. mined only in the southern part of the Black Hills of South Dakota, where the various types of lithium-bearing pegmatite could be used to develop untried processes of beneficiation. Concentrates from these operations are shipped to the corporation&apos;s chemical plant in St. Louis Park, Minn., where actual extraction of lithium and production of commercial compounds takes place. Nature of Deposits The geology of the southern Black Hills pegmatite deposits is admirably presented by a U. S. Geological Survey publication.&apos; Only the factors pertinent to exploitation need be mentioned here. Lithium Corp. has been interested primarily in three deposits, the Edison, the Mateen, and the Longview-Beecher No. 2. The history of these deposits dates back to the mining boom of 1880 to 1900 in the Black Hills, when most of the deposits were prospected for tin by the ill-fated Harney Peak Tin Mining Co. The three deposits described here, however, lay idle and unwanted until Lithium Corp. opened the Edison mine in 1943 and the Mateen and Longview-Beecher No. 2 in 1951. Edison Deposit: The Edison deposit is about a mile southeast of Keystone, S. D., on the northeastern flank of the Harney Peak uplift. The deposit consists of no less than four and probably at least six separate pegmatites that coalesce in a central mass from which the individual pegmatites finger outward and downward in complexly folded schist and gneiss beds of the country rock.

Jan 1, 1956

By Ralph Monaghan, Arthur Youmans

General principles of scintillation counter-type instruments for radioactivity logging are discussed and the various possible causes for instability are examined. It is shown how instrumentation problems are solved. Means are discussed for minimizing drift and instability due to "fatigue" of the photomultiplier tube and neutron activation of the crystals. INTRODUCTION Neutron and gamma-ray logs made with logging instruments employing scintillation counters are now routinely available from most of the logging service companies. The superior characteristics of scintillation counters by comparison with older types of detectors promises to bring about important improvements in quantitative interpretation of radioactivity logs. Moreover, new types of logs can be made with scintillation counters which are not possible with other detectors. But in spite of the obvious superiority of these counters with respect to efficiency, speed, and versatility, they suffer from a number of inherent difficulties and weak- nesses. Unless these inherent diffi-culties are fully recognized and satisfactorily overcome by sound engineering of the associated instrumentation, scintillation counter logs are particularly likely to exhibit drift and instability of sensitivity. This defect in logs when they are intended for quantitative interpretation is intolerable and more than outweighs any advantages over the older type of instrumentation when the latter is operating correctly. SCINTILLATION COUNTER OPERATION In general all radioactivity logging instruments consist of a detector sensitive to gamma radiation or to neutron radiation coming from the strata. This radioactivity is either due to naturally decaying radioactive elements in the rock, radioactivity induced in the rock by a neutron source in the instrument, or scattering by the rock of neutrons or gamma rays coming from a source in the instrument. In the scintillation counter the gamma radiation or neutron radiation reacts with the scintillation phosphor to produce light pulses. These light pulses are then converted to amplified electrical pulses by the multiplier phototube. Basically the problem of making a good scintillation counter logging instrument is to make the radiation sensitivity of the system as nearly constant as possible. The size of each scintillation counter pulse is dependent on the energy of the individual quantum of radiation being detected. In normal radiation logging, gamma rays of all energies, up to some maximum value, reach the detector. If a suitable scintillator is used, such as a sodium iodide crystal, each gamma ray produces a number of photons proportional to the energy absorbed by the crystal from the impinging radiation. The light flashes are detected by means of a photo-multiplier tube which contains not only a photo-sensitive cathode from which photoelectrons are collected, but also an amplifier, called an electron multiplier, built inside the photomultiplier tube; the electron multiplier usually has about 10 stages, having an over-all gain of perhaps 500,000. In an ordinary gamma-ray log one wishes to detect all gamma rays down to the lowest possible energy; therefore, one wishes only to reject the "noise" pulses which are invariably present due to thermal emission of electrons from the photo-cathode of the photomultiplier. In other radioactivity logs it may be desired to measure the radiation within a particular energy band, or above

Jan 1, 1958

By Arthur A. Center

AT the beginning of 1944 it was expected that the production of metallic zinc in the United States from domestic and foreign concentrates would exceed the 1943 figure though domestic production of concentrates was expected to drop below the 1943 rate, mostly in the Tri-State area. Imports of concentrates were estimated to more than take care of such deficiency. North American concentrate production, available for import to the United States or elsewhere during the year, was estimated at over 200,000 tons recoverable zinc content; South American at about 65,000 tons; Australian at about 50,000 tons. Production of both concentrates and metal in the United States, however, did drop, attributable in considerable part to man-power shortage in the industry. However production exceeded consumption, which fell off, and stocks of metal increased. These stocks have increased since the middle of 1942 but production and consumption are coming nearer to a balance. The A, B, and C premiums, which have played an important part in keeping up domestic production of concentrates, extend only to the middle of 1945 by present legislation. Congress is being asked for their continuance during the war and

Jan 1, 1945

By R. D. Nelson, J. C. Shyne

The ß and a ß transformations in plutonium were studied with particular emphasis on the transformation kinetics and microstructure. Significant observations are: 1) The kinetic data show conclusively that the ß — a transformation in high-purity plutonium can proceed isothermally with no athermal component. 2) Plastic deformation of the stable (3 phase retards the subsequent (3 — a transformation. 3) Plastic deformation of the stable a phase accelerates the a — ß transformation; the acceleration is attributed only to residual stresses. 4) The a and a?a volume changes occur anisotroPically in textured plutonium. 5) An apparent crystallogvaphic relationship exists between the parent and the product phases of the and (3 — a transformations. 6) Both applied uniaxial compressive stresses and uniaxial tensile stresses raise the starting temperature for the ß — a transformation. 7) A given uniaxial tensile stress favors the a — ß transformation more than an equivalent applied uniaxial compressive stress opposes the transformation. These observations of the (ß —a and a — ß phase changes in plutonium are consistent with known mar-tensitic transformations. ThIS paper elucidates some of the characteristics of the a— ß and ß —a transformations in plutonium. Because considerable conjecture exists about the mechanisms by which the phase transformations occur in plutonium, experiments have been performed to provide indirect information concerning the mechanisms responsible for the a —ß and ß -a transformations. Indirect information is of particular value in the study of plutonium because of the experimental difficulties presented by the metal. Single crystals have not been produced in any of the allotropes. The large density results in high X-ray and electron-absorption factors and consequently complicating X-ray and electron diffraction. The kinetics of ß — a and a — ß transformations of plutonium and the behavior of the transformations under a variety of conditions have been investigated in detail. Information about the mechanisms of the allo-tropic transformations of plutonium was obtained indirectly from three sources: 1) the effect of plastic deformation of the stable parent phase upon the transformation kinetics; 2) the behavior of the metal transforming under applied stresses; and 3) the microstruc-tural and crystallographic features between parent and product phases. PHASE-TRANSFORMATION CHARACTERISTICS In characterizing solid-state phase transformations in metals and alloys, it is useful to define several types of transformations. An aim of the present work was to identify the low-temperature transformations in plutonium by type, i.e., as martensitic or nonmar-tensitic. Practical definitions for these terms follow. The terms commonly used to categorize phase transformations lack universally accepted definitions. This confusion arises doubtlessly because some terms specify crystallographic or morphological character while other words have a kinetic or a thermodynamic connotation. For example, martensitic specifies certain definite crystallographic restrictions. Unfortunately, martensitic is sometimes used in an ill-defined way to imply kinetic characteristics. Further confusion attends the use of such expressions as nucleation and growth, diffusional, and massive. From time to time new systems of phase-transformation nomenclature are suggested; unfortunately none of these has gained general acceptance.1,2 The authors of the present paper have no intention of entering the controversy. We recognize that some readers may object to the nomencliture used here. For exampie, the terms military and civilian have recently been used in much the same way as martensitic and non-martensitic are used in this paper. This paper is intended to describe several specific details of the low-temperature phase transformations in plutonium. The authors have found it useful to identify these transformations as martensitic; the term was chosen as the best available to describe the experimentally observed features of the transformations studied. A martensitic transformation is one that occurs by the cooperative movement of many atoms; the rearrangement of atoms from parent to product crystal structure occurs by the passage of a mobile semico-herent growth interface. The geometric features characteristic of a martensitic transformation are a specific orientation relationship between the product and parent phase lattices, a specific habit-plane orientation for the growth interface, and a shape change with a specifically oriented shear component. There is no alloy partition between the parent and product phases in a martensitic transformation. Martensitic transformations may display either athermal kinetic behavior or thermally activated isothermal kinetic behavior. Some martensitic transformations occur isothermally, although more commonly martensitic transformations are athermal. Isothermal martensitic transformations are suppressible by rapid cooling. In athermal martensitic transformations, nucleation and growth are not thermally activated and the transformations are essentially time-independent. Nucleation, growth, or both can be thermally activated in isothermal martensitic reactions. Transformation of the parent phase into a marten-

Jan 1, 1967

Raymond Weir Smyth, born Nov. 3, 1888, was the son of Herbert Weir Smyth, professor of Greek Literature at Harvard University. He graduated (A. B.) from Harvard in 1909 and later pursued advanced studies there in chemistry and in metallurgy. He held the position of metallurgist for the American Steel and Wire Co. at Worcester, Mass., and also for the Steel and Tube Co. at Youngstomn, Ohio. For a time he was inspector of munitions for the British Government and stationed at the Railway Steel and Spring Co. at Latrobe, Pa. For a short time, in 1917, he was Inspector of Ordnance for the U. S. Government, and the following year, having entered the U. S. Naval Reserve Force, he was ordered in a similar capacity to the Midvale Steel Co. In September, he removed to the Navy Yard, League Island, Philadelphia, to train for the obligatory minimum of six months&apos; sea duty. There he contracted influenza, which was followed by pneumonia, from which he died, September 27, at the Navy Yard Hospital. Captain Braxton Bigelow* Captain Braxton Bigelow was the son of Major John B. Bigelow, U. S. A., retired, and grandson of the late John Bigelow, author, and Minister to France under President Grant. Captain Bigelow graduated

Jan 1, 1920

By W. R. Bean

Probably few, if any, of the many serious problems confronting malleable foundries have been more difficult of solution than the question as to why malleable that is ductile, black in fracture, and normal in all respects before galvanizing should, by that process, be rendered brittle, brilliantly crystalline or "white" in fracture, and of low resistance to shock. So far as we are aware, the technical literature contains no data or discussions on this subject, except two referencesl,2 of a general character. It is apparently a question that every one concerned, producer and consumer alike, has been willing to evade as far as possible. Various theories as to the cause of the deterioration have been given but such checking of these theories as we have done indicates that there was no sound basis for most of them. This work on the galvanizing of malleable was first undertaken in 1916, and has continued until the present time. We now feel that for all practical purposes we have reached a solution and are glad to be able to offer it in a form that can be readily applied to production processes. It is impossible to give here a detailed account of the early work done on this problem. A great number of tests were instituted and an enor-

Jan 1, 1923

By W. R. Bean

Probably few, if any, of the many serious problems confronting malleable foundries have been more difficult of solution than the question as to why malleable that is ductile, black in fracture, and normal in all respects before galvanizing should, by that process, be rendered brittle, brilliantly crystalline or "white" in fracture, and of low resistance to shock. So far as we are aware, the technical literature contains no data or discussions on this subject, except two referencesl,2 of a general character. It is apparently a question that every one concerned, producer and consumer alike, has been willing to evade as far as possible. Various theories as to the cause of the deterioration have been given but such checking of these theories as we have done indicates that there was no sound basis for most of them. This work on the galvanizing of malleable was first undertaken in 1916, and has continued until the present time. We now feel that for all practical purposes we have reached a solution and are glad to be able to offer it in a form that can be readily applied to production processes. It is impossible to give here a detailed account of the early work done on this problem. A great number of tests were instituted and an enor-

Jan 1, 1923

By J. T. Eash, E. M. Wise

In a previous communication1 the improvement in slrength, harden-ability and color, occasioned by replacing gold in a typical gold-silver-copper alloy by various amounts of platinum, or palladium, was discussed. In the present paper the results of further studies upon the constitution and the nature of the hardening transformation in these alloys are presented. This research may be summarized as follows: 1. The liquidus and solidus have been determined for the alloys of the palladium and platinum series. Cooling curves were utilized for determining the liquidus of the palladium alloys but this method proved unsuitable for the platinum alloys so that a novel quenching method was utilized for the latter. Both the liquidus and solidus of the palladium alloys increase steadily with the palladium content. The liquidus of the platinum alloys increases rapidly with the platinum content, while the solidus temperature increases with the platinum content up to about 14 atomic per cent platinum, but suffers no further increase with additional increments of platinum up to 20 atomic per cent at least, owing to a peritectic reaction. 2. Palladium, and even more effectively platinum, reduces the rate of grain growth. Owing to this fact and to the increase in the solidus temperature, "overheating" does little or no damage to alloys containing reasonable quantities of these elements. This is confirmed both by tensile tests and metallographic examination. 3. The excess phase present in one of the high-platinum-content alloys has been isolated and chemically analyzed and was found to consist almost wholly of platinum, gold, and copper, evidently derived from the compound AuCu, by the partial replacement of gold by platinum. 4. The variation in the solubility of this platinum-content phase in the alpha solid solution with the temperature has been determined. This

Jan 1, 1933

By Timothy Collins

There was once a speculative period of interest in small mining companies that is commonly referred to as "the uranium boom of the 50&apos;s." In the late 60&apos;s, there was a second mining stock boom: it centered around uranium and silver, when silver had reached a new high of $3.60. In the mid 1970Js, there may be a new boom in the making, and it appears that substantial public and institutional interest in mining equities will finally result in a viable long-term capital market rather than the boom-or-bust pattern of the 50&apos;s and 60&apos;s. The reason for Wall Street&apos;s renewed interest in mining is understandable: most mineral commodities have recently gone up in price. Domestically, these price increases have come in the wake of the inflationary spiral unleashed by years of unbridled government deficit spending and erratic fiscal and monetary policies. Internationally, of course, the biggest push for higher prices has come from third-world countries whose primary income derives from indigenous natural resources. Many of these countries-whose fiscal and monetary policies haven&apos;t been models of excellence either-have attempted to cope with the worldwide economic mess by forming cartels that could control the price of commodities. What&apos;s happened to petroleum is well-known; what&apos;s happened to copper, bauxite, phosphate, and uranium is part and parcel of the same syndrome.

Jan 9, 1975

By the courtesy of Sir Robert Hadfield, we have received the fol¬lowing communication relating to the development and encouragement of science and research in Germany at present. These statements have been translated by Sir Robert from various German sources, and are presented here as an indication of what Germany is doing not only to further her military power, but also to prepare for the period of trade rehabilitation to which she is looking forward after the close of, the war. KAISER WILHELM TRUST FOR PROMOTION OF WAR SCIENCE The Kaiser has approved the foundation of a Trust with the name given above. The aim of the Trust is to further the development of scientific and technical aids to warfare, by uniting the scientific and the military forces of the country for work together. The scientific Work is to be carried on by the following technical committees (or commissions) (1) Committee for the chemical raw materials, for the production of munitions-manufacturing materials. (2) Committee for chemical war materials (powder, explosives, gas, and the like). (3) Committee for physics, including ballistics, telephony, telegraphy, determination of targets and distances, measurements, and the like. (4) Committee for engineering and communication. (5) Committee for aeronautics. (6) Committee for obtaining and preparation of metals.

Jan 8, 1918