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By J. H. Brophy, S. J. Michalik

A constitution diagram for the system Mo-Ir has been determined. The maximum solubility of iridium in molybdenum is 16 at. pct at 2110ºC and decreases to less than 5 at. pct at 1500°C. The solubility of molybdenum in iridium is 22 at. pct. Three intermediate phases appear in the system: 8 MoJr, having the p-tungsten structure; a phase, a cornplex tetragonal structure; and the hcp ? phase. Metallography, melting point determinations, X-ray diffraction and fluorescence, and electron micro-probe unalyses were employed in establishing the diagram. PREVIOUS to the present investigation, the intermediate phases in the Mo-Ir system were identified, but no detailed account of the phase diagram has been reported in the literature. Raub1 investigated alloys of Mo-Ir over an extensive range of composition between the temperatures of 800º and 1600°C. The in-termetallic compound MosIr was found to exist with nearly pure molybdenum, as the solubility of iridium in molybdenum was not detectable parametrically in this temperature range. MO3Ir was found to be iso-morphic with a ß-tungsten type structure, having a parameter of 4.959Å. An intermediate hcp phase, designated as the ? phase, ranged in composition from 52 to 78.5 at. pct at 800ºC, and from 41 to 78.5 at. pct Ir at 1200°C. Parameters noted for the ? phase were as follows: at 42.7 at. pct Ir, a = 2.771i0, c = 4.4366, c/a = 1.601; at 78.5 at. pct Ir, a = 2.736A, c = 4.378A, c/a = 1.600. Molybdenum was found to be soluble in iridium up to 16.5 at. pct Mo (83.5 at. pct Irj, with the parameter of iridium increasing to 3.845A at the solubility limit. Knapton,2 who investigated alloys between 15 and 85 at. pct Ir, essentially agreed with Raub's data, but, in addition, found a a phase in as-melted alloys near 25 at. pcto Ir. The oaphase lattice parameters were a = 9.64Å, c = 4.96Å, c/a = 0.515. The a phase was replaced by the 8 -tungsten phase on annealing at 1600°C. Knapton concluded that the a was stable only at elevated temperatures, and placed the composition of the a phase at approximately 30 at. pct Ir. The intermetallic compound Mo3Ir, with a lattice parameter of 4.965A, was included among the 8-tungsten structures reported by ~eller.' Matthias and Corenzwit,4 and Bucke15 studied the superconducting nature of MosIr, and reported a superconducting transition temperature of 8.$K. The present investigation describes the phase relationships in the Mo-Ir alloy system determined by melting point measurements, X-ray diffraction and fluorescence, and metallography. EXPERIMENTAL PROCEDURES Alloys for the determination of the phase diagram were prepared from powders. Commercial 99.9 pct Mo from Fansteel Metallurgical Corp. and 99.9 pct Ir powder from J. Bishop and Co. Platinum Works were used. The powders were weighed to nominal compositions, mixed, and then pressed, without binder, into compacts weighing 4 to 6 g. These were presintered in uacuo between 1200' and 1400°C for 1 hr, to reduce the degree of spattering during subsequent arc-melting. The compacts were arc-melted in a nonconsumable tungsten electrode furnace six times on alternate sides on a water-cooled copper hearth in an atmosphere of zirconium-getter ed argon at 500 mm of mercury pressure. In almost all cases, this procedure yielded buttons of satisfactory homogeneity. The composition of all melted buttons were confirmed by X-ray fluorescent analysis using the experimentally determined ratio of the iridium La1 line intensity to that of the molybdenum Ka1 line as a function of composition. In this determination four alloys analyzed by wet chemical methods were used as standards. An uncertainty range of ±1 at. pct has been attributed to all indicated compositions. All heat treatments and solidus measurements were carried out in tantalum resistance heating elements in vacuum conditions of 10-4 to 10-5 mm of mercury. A detailed account of this procedure has been reported by Schwarzkopf and Brophy.8 In the heat treatment and solidus measurements of iridium-rich alloys (50 at. pct Ir or greater), a tungsten lining was inserted into the tantalum resistance heating element because of a eutectic reaction which occurs between iridium and tantalum at 1948ºc.7 Heat treatments and solidus measurements carried out at compositions less than 40 at. pct Ir both with and without tungsten linings within the resistance

Jan 1, 1963

By E. A. Breitenbach

A computer program has been developed to afford rapid and complete quantitative log analysis for exploration and production decisions. The computation consists of automatic selection of tops and bottoms of porous intervals from the digitized data, and then point-by-point calculations within each selected interval. Nearly all log types can be analyzed. This paper presents the calculation techniques found to be appticable to machine evaluation and gives examples of their use. INTRODUCTION As the quantitative interpretation of well logs entails repetitive use of charts and equations, it is natural that digital computer programs would be written. A Universal Log Interpretation Computer Program (ULICP) has been developed to afiord rapid and complete analysis for exploration and production decisions. Application of this program enables the log analyst to: (I) apply rapid quantitative log analysis for exploration and production decisions on either a field, a well or on a single zone basis; (2) apply concepts of interpretation requiring detailed numerical analysis; (3) analyze all porous intervals on each log, rather than a few selected zones, and complete the analysis in less time than previously required. Computations are reported for every digitized point in each zone; (4) use empirical techniques applicable to a given area as an integral part of the computation; (5) experiment with the empirical coefficients and exponents in the interpretation equations to find the best possible solution; and (6) automatically plot both the original and computed data to scales analogous to the field prints. The primary utility of a log interpretation program stems from its ability to do an overwhelming amount of work with very little man-power. If a calculation procedure or thought process can be formalized to the extent that step-by-step logic can be written, a computer program can be developed that follows this logic. The major question is one of economics. A feasibility study of the costs for such a program indicates that digital processing is economical primarily as a means of increasing the productivity of the log analyst. In effect, the probability of missing productive intervals in any well, because of a lack of time to do detailed calculations, is greatly reduced. The nucleus of ULICP is programmed to compute large sections of a suite of logs by selecting zones automatically and then performing all pertinent computations on a data point by data point basis within each zone.'.' An entire suite of logs can be processed in this manner with very little manual intervention. Sufficient programming logic is available so that each log analyst can request computations pertinent to his area. These requests are made by simple additions or deletions of information on the input header cards. Hence, the log analyst is always in complete control of the computation process. The evaluation of a suite of logs requires pre-editing, digitization, computation, presentation of results and interpretation. Work by the log analyst is reqilired only in pre-editing and interpretation. Thus, he is allowed more time for comprehensive interpretation, rather than calculation. For continuity, the discussion of ULICP is organized sequentially: pre-editing, digitization, computation and presentation of results. DISCUSSION PRE-EDITING The extent of pre-editing prior to computation is dependent on the format of the original data. For analog prints, it requires inspection, correlation and editing of the logs, plus the entering of required data an special forms. For digitized data such as magnetic tape field recordings, only the special forms are necessary. The process for analog prints will be given here. The inspection and correlation process involves the selection of sections for digitization and the correlation of the traces to a common depth. To decrease the cost of digitization, traces that exhibit large variations in shale formations can be redrawn to a non-zero baseline. The next step is to enter all pertinent data on the input header cards. The header cards presently used for ULICP are presented as Figs. 1 through 6. Cards 1, 2, 3 and 4 (Fig. 1) are defined as the Main Header Cards. They describe the particular well for output identification and give basic information. Cards 5 through 15 (Figs. 2 through 6) are defined as the Block Header Cards. As such, they define the log types and the interpretation parameters for the block of data immediately following. Cards 1 through 10 are required for every computer run. Cards 11 through 14 pertain only to nuclear logs. Card 11 is required if any nuclear log is supplied, and cards 12 through 14 are required only when gamma-ray, density or neutron log data, respectively, are supplied. Card 15 (Fig. 6) must be supplied when cross-plot calculations are required. Either two- or three-component

Jan 1, 1967

By H. E. Rowen

As high grade iron ore deposits dwindle and costs rise, sintering becomes more and more important. The steel industry is now faced with beneficiation problems once peculiar to nonferrous work. Succeeding articles describe recent advances in this field. Here is presented the first chapter of a history still being written. SINTERING, for the purpose of this discussion, is defined as the art of burning a solid fuel with 90 to 95 pct ash content. Considering problems of combustion involved in keeping a home furnace burning properly with 12 to 20 pct ash in the fuel, it is evident that combustion represented by the definition has to be right or nothing is going to happen. Our forefathers discovered that many ores containing metals essential to the steadily rising standards of living were associated with elements such as sulfur and arsenic, which had to be removed before refining. This they did by utilizing the solid fuels they had available-the sulfur or other readily combustible components-to create roasting heat. One of the early methods is demonstrated in an old woodcut of the roast heap, Fig. 2. Ore was broken into chunks, piled on an ignition layer of solid fuel-logs in this case-and then. ignited. The sulfide ores roasted as the sulfur burned out. As shown in the background, the countryside was rapidly denuded of all vegetation by the great quantities of SO2 and other liberated gases.

Jan 1, 1961

By Robert Yerkes

THE following is a brief account of the methods of measuring intelligence especially prepared for use in the U. S. Army, of typical results, and of some of their immediately practical applications. It has been prepared for the assistance of army examiners and for the information of all who are interested in the relations of scientific placement to military efficiency. PURPOSE OF THE INTELLIGENCE TESTS Under the direction of the Division of Psychology, Medical Department, and in accordance with provisions of War Department General Order No. 74, mental tests are given recruits during the 2-wk. detention period. These tests provide an immediate and reasonably dependable classification of the men according to general intelligence. Their specific purposes are to aid: 1. In the discovery of men whose superior intelligence suggests their consideration for advancement; 2. In the prompt selection and assignment to development battalions of men who are so inferior mentally that they are suited only for selected assignments; 3. In forming organizations of uniform mental strength where such uniformity is desired; 4. In forming organizations of superior mental strength where such superiority is demanded by the nature of the work to be performed; 5. In selecting suitable men for various army duties or for special training in colleges or technical schools; 6. In the early formation of training groups within regiment or battery in order that each man may receive instruction and drill according to his ability to profit thereby;

Jan 2, 1919

By Shiou-Chuan Sun

Most previous work on sedimentation of coal1 and mineral2,3 suspensions has been conducted in graduated 1-liter glass cylinders of 6-cm diam. With this type of large container it is often difficult to see through the suspension and tedious to perform a large number of tests. Furthermore, the heavy glass walls and the graduation lines of glass cylinders cause internal and stray reflections, respectively. To obviate these difficulties, an Atlab Emulsion Viewer from Arthur H. Thomas Co. was adopted as an alternative apparatus. Equipment: The viewer,4 shown in Fig. 1, consists of: 1) a stainless steel frame rack holding 21 flat-bottom Nessler tubes or an ungraduated replica 1.64 cm ID and 1.80 cm OD, 2) a movable masked 150-w lumaline lamp behind the tubes, and 3) a scaled glass panel with 100 vertical divisions in front of the tubes. The tubes are snugly held by springs in slots formed by spacer bars, which also serve as shields to eliminate stray light. The lumaline lamp is mounted behind a slit in a movable housing so that it can be positioned behind the suspension to be examined. The lowest or 100-division line on the front glass plate is leveled with the upper side of the bottom of all tubes. The scaled portion of each tube, roughly 19 cm high and 40 ml in volume, is used to study coal and mineral suspensions.

Jan 1, 1959

By L. F. Engle, M. A. Hewedi

SUMMARY Initial interest in using solutions of ammonium salts to leach native copper was documented in notes from an AIME meeting in 1871; By 1916-1917, application of the NH3-CO2-H2O system to recover nonferrous metals attained commercial significance, when it was used as a process for copper recovery by Kennecott Copper Corporation and Calumet & Hecla Mining Company. The Caron work in the early 1920s, Freeport Sulphur Company’s achievements leaching Cuban laterites during World War II, out- standing accomplishments in both eastern and western Canada, recovery of manganese related to the work of Dean -- all serve as landmarks as this One Century Review surveys a base for future technology. Current emphasis on compatibility of metals-producing systems with the need to meet environmental protection criteria provides special encouragement to researchers and engineers to find accept- able ways of recovering metals. The ever-present demand of management to design, build and operate facilities on a profitable basis provides additional impetus to apply information from the technical literature to that need. Examination of the general approach to this paper will reveal much that is firm and positive with respect to empirical results -- extractions, recoveries, amenability to familiar proven equipment and materials of construction common to the industry. Although there are many references, there are gaps in the basic scientific data that if filled could lead to even more usefulness; the paper attempts to indicate where further information is needed.

Jan 1, 1973

By Frederick K. Allgaier

As part of an ongoing research program, the Bureau of Mines, U.S. Department of the Interior, is monitoring surface subsidence over six longwall panels at three Utah coal mines. These sites are characterized by mining depths of 244 to 610 meters (800 to 2,000 ft .), thick and massive sandstone layers in the overburden strata, multiple seam mining, extraction heights of approximately 1.8 to 3 meters (6 to 10 ft.), and rugged surface topography. Maximum subsidence, angle of draw, timing relative to mining, horizontal strain, and rate of subsidence development are being determined and correlated with mining and geologic variables. Results to date indicate the maximum vertical subsidence over the monitored panels ranges from 0.6 to 0.9 meters (2 to 3 ft.). The major factors controlling the amount of subsidence are the panel dimensions and the status of adjacent panel mining. Only minor surface cracking at the panel ends was evident at any of the sites. In all cases, there was a time lag of several months between the start of mining and subsidence at the surface. As subsequent panels are monitored and additional data become available, better estimates of the effect of various site characteristics on the subsidence will be possible. Ultimately, improved prediction capabilities will allow mine operators in the West to evaluate the potential for subsidence-related damage which could affect the current or future land use above the mine.

Jan 1, 1982

The Institute maintains a dual relationship with students (1) an individual relationship with a Student Associate, and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Student Chapters 1 The conditions of Student Associate¬ship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 74 and following pages) During 1934, sundry amendments were made for the purpose of improving the student relationship Post-graduate students are now eligible, and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in June With his regular dues, each Student Associate is entitled to receive during the year his choice of MINING AND METALLURGY, METALS TECHNOLOGY, MINING TECHNOLOGY, PETROLEUM TECHNOLOGY, or COAL TECHNOLOGY, and on payment of an additional fifty cents he can have both MINING AND METALLURGY and any one of the others He is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Elements of the Petroleum Industry" at the reduced prices applicable to Members, he has the privileges of the Engineering Societies Personnel Service and the Engineering Societies Library, and he is not only invited but urged to attend all meet¬ings of the Institute, its Divisions and its Local Sections The Institute wants to extend the hand of professional fellowship to students following mineral industries curricula

Jan 1, 1952

Geological and Natural History Survey of Minnesota, Minneapolis, Minn W. H Emmons, Director A list of publications will be sent upon application Orders for publications should be addressed to The University of Minnesota Press, Minneapolis, Minnesota The Geological Survey of Minnesota has a record of long and useful service Some of the papers published have been outstanding in their field A series of 24 Annual Reports, covering the years 1872 to 1895-98, inclusive, was issued, of which 16 are still available at a price. More important however, are the six volumes of Final Reports, in which is collected the material presented in the earlier Annual Reports. All the strictly geological papers are found in four of the volumes of the Final Reports. vol 1 (1872-1882), principally geology by counties, 2 (1882-1885), same as 1, 4 (1896-1898), same as 1, 5 (1898-1900), Structural and petrographic geology Prices for each volume, leather $3, cloth $2 50, excluding postage, unless other directions accompany the order, volumes of the Final Reports will be sent express collect. A series of Bulletins has been issued, of which a few are out of print. Considering only those available, and of greatest interest, they are: Bulletin 5, Natural gas in Minnesota, by N H Winchell (1889), 50 cents, 6, Iron ores in Minnesota, their geology, discovery, development, qualities and origin, by N H Winchell and H V.

Jan 1, 1933

The Institute maintains a dual relationship with students: (1) an indi¬vidual relationship with a Student Associate; and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Stu¬dent Chapters. 1. The conditions of Student Associateship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 57 and following pages). During 1934, sundry amendments were made for the purpose of improving the student relationship. Post-graduate students are now eligible; and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in June. With his regular dues, each Student Associate is entitled to receive during the year his choice of Mining and Metallurgy, Metals Technology, Mining Technology, Petroleum Technology, or two "classes" of Technical Publications; and on payment of an additional fifty cents he can have both Mining and Metallurgy and any one of the others. He is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Ore Deposits of the Western States" at the reduced prices applicable to Members; he has the privileges of the Engineering Societies Employment Service and the Engineering Societies Library; and he is not only invited but urged to attend all meetings of the Institute, its Divisions and its Local Sections. The Institute wants to extend the hand of professional fellowship to students following mineral industries curricula.

Jan 1, 1938

The Institute maintains a dual reltionship with students: (1) an individual relationship with a Student Associate; and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Student Chapters. 1. The conditions of Student Associateship are set forth in Section 9, Article I, of the Bylaws of the Institute (see page 60 and following pages). During 1934, sundry amendments were made for the purpose of improving the student relationship. Post-graduate students are now eligible; and associateship can be maintained, with the payment of the regular dues of $2 per year, for 18 months following graduation in. June. With his regular dues, each Student Associate is entitled to receive during the year his choice of MINING AND METALLURGY, METALS TECHNOLOGY, MINING TECHNOLOGY, PETROLEUM TECHNOLOGY, or two "classes" of Technical Publications; and on payment of an additional fifty cents. he can have both MINING AND METALLURGY and any one of the others. He is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Elements of the Petroleum Industry" at the reduced prices applicable to Members; he has the privileges of the Engineering Societies Personnel Service and the Engineering Societies Library; and he is not only invited but urged to attend all meetings of the Institute, its Divisions and its Local Sections. The Institute wants, to extend the hand of professional fellowship to students following mineral industries curricula.

Jan 1, 1941

By A. A. Venghiattis

This paper is discussed not because of its intrinsic value but because it has been related by its authors to the oilwell gun perforators. It is well known that conditions almost ever present in oilwell perforations are the overburden and the presence of the casing. Because of the lack of information in the paper on the dimensions or confinement of the target rocks, one is led to guess that they were not confined at all and, particularly, that no steel front plates were used on the impact face of the rocks to materialize the presence of the cemented casing. This situation, plus the fact that small steel balls have been used as projectiles instead of actual bullets, makes the whole thing unapplicable to oilwell perforation. When shooting is performed against target rocks confined (as shown on Fig. 1) in such a way as to give a fair image of the overburden applied to the formation to be perforated, as well as of the cemented casing, the following are found. 1. There is no cratering worthy of mention, even with bullets having 10 times higher impact energy per unit projected area than the steel balls mentioned in the article. This has been confirmed with sandstone as well as with other rocks (granite, limestone and chalk). See Figs. 2 and 3. 2. Penetrations vary closely as the logarithm of the impact velocity. On this matter I have established the relation

By E. J. Quinn, M. F. Fogler

In a recent paper, Rawdon and Mutchlerl gave some exceptionally interesting results on the Brinell and scratch hardness of severely cold-worked metals. In their work, they found that, on continued cold rolling, the metal hardened up to a particular point and then reversed and became softer; this was true for both Brinell and scratch hardness values. The generally reported behavior2 of metals, with respect to Brinell tests on cold-worked material, is that the metals harden up to a certain point and then, on further cold rolling, no change in Brinell hardness occurs. Jeffries and Archer3 state that there is little difference between the scratch hardness of annealed and cold-worked metals; the work of Faust and Tammann4 also indicated no difference between the hardness of annealed and cold-worked copper. Rawdon and Mutchler found, when they plotted the reduction ratio (initial thickness divided by thickness after rolling) against the hardness value for the cold-rolled material, that the hardness number increased up to a reduction ratio of about 3 and then decreased and became even smaller than that for the annealed metal. This behavior was reported for both scratch and Brinell hardness; Figs. 1 and 2 show their results for Brinell hardness on the metals for which they published data. This is an exceptionally interesting phenomenon, if it occurs under all conditions of rolling, and would have an important bearing on the practice of cold

Jan 1, 1925

By John W. Burd

A system is described for the simultaneous deposition of epitaxial layers on as many as eight substrates. A high degree of uniformity of both physical and electrical characteristics is achieved in the films. Variation of film thicknesses is consistently less than ±10pct within a wafer and from wafer to wafer within a run with the variation typically on the order of 55 pct. Composition variation of GaAs1-x PX layers within a wafer and from wafer to wafer within a run is consistently less than 51 pct. Electrical evaluation of the films by several techniques indicates excellent doping uniformity within a wafer and from wafer to wafer within a run. Mobilities for lightly doped GaAs films at 300°K are consistently >6000 cm2 v-1 sec-1 and mobilities > 7000 cm2 v- 1 sec-1 are regularly attainable. Techniques for the preparation of material with carrier concentrations from 1 x 1015cm-3 to 1 x 1019 cm-3 n-type and 5 x 1016 to 5 x 1018 cm-3 p-type are discussed. METHODS for the preparation of 111-V compounds by vapor phase reactions have been extensively reported in the literature.1-6 Almost all of the apparatus described for these various methods are suitable for processing one or at the most a very limited number of wafers simultaneously. With the recent rapid advances in the use of vapor grown GaAs for microwave oscillators and GaAs1-xPx as visible light emitters the requirements for these materials are steadily increasing. In order to satisfy these requirements it is necessary to move from a laboratory scale apparatus to one which is capable of processing a large number of wafers simultaneously. Desirable features would be a high degree of uniformity among the wafers and good reproducibility from run to run. The apparatus to be described fulfills these requirements very well. DISCUSSION The various methods reported in the literature can be classified under three headings: 1) closed tube, 2) open tube, and 3) the close-spaced method. Of these three the open-tube method is the most amenable for scale-up to a manufacturing process. It is the most versatile and the various operating conditions can be more precisely controlled than with the other two methods. A number of chemical reactions may be used to achieve vapor-phase growth of 111-V compounds. Sev-era1 of the more generally used reactions are shown in Fig. 1. All of these reactions have the following points in common: 1) generation of a volatile group III(Ga) species by the reaction of the transport agent (halide or HC1) with either Ga or GaAs, 2) introduction of the Group V(As and/or PI component, 3) a method of adding dopant, if desired, and 4) a region in which deposition from the vapor will occur and form as a single crystal epitaxial film on the substrates. The laboratory scale reactors permit the hot re-actant gases to flow into the relatively cooler deposition zone and pass successively over the several substrates which are arrayed along the long axis of the tube parallel to the gas flow. With this arrangement the composition of the reactant stream is continually changing as solid material is deposited on each successive substrate. As a result of this changing gas composition the reaction driving force also changes from substrate to substrate and the degree of uniformity of layer thickness, doping level, and so forth, is poor. This effect can be partially overcome by imposing a controlled temperature gradient along the deposition region to compensate for change in gas composition. However, even when this is done variations in layer thickness on the order of 30 to 40 pct are common and as high as 50 pct are frequently experienced between adjacent wafers in the tube. To expand this arrangement to a large number of wafers would only increase the nonuniformity from the first to last wafer in the line. From the above discussion the two undesirable features of changing gas composition and temperature gradient become evident. A reactor system which eliminates or minimizes these undesirable features is one in which the apparatus is mounted vertically as shown schematically in Fig. 2. The vertical mounting permits the disposition of a number of substrates on a suitable support so that all wafers are at the same vertical height in the furnace and hence at essentially the same temperature. By using only a single row of wafers the reactant gas mixture passes over only one substrate in its path through the reactor. Thus the two undesirable features of changing gas composition and temperature gradient are minimized. An additional design feature which further minimizes temperature variations is rotation of the substrate holder. Rotation serves to integrate any radial temperature gradient existing around the resistance heated furnace. A photograph of a reactor assembly at the completion of a run is shown in Fig. 3. MATERIAL PREPARATION Apparatus. Although any of the several chemical systems shown in Fig. 1 are adaptable for use in this apparatus the one generally used is System 2, the hydride synthesis system. This system has been de-

Jan 1, 1970

By H. A. Lequear, J. D. Lubahn

A sudden change from one constant strain rate to another during a tensile test causes an unusual transient in aluminum alloy 61ST. A sudden change from one constant stress to another during a creep test does not produce an unusual transient in this material. A specially devised test shows that the nature of the previous steady-state conditions, which the sudden change disturbs, is one of the factors affecting the transient behavior. Some of the observations may be explained in terms of strain aging. USUALLY a sudden change during a tensile test from one constant strain rate to another causes a small, abrupt vertical shift from one stress-strain curve to another, parallel one. This behavior is apparently characteristic of all metals at very low temperatures and of many metals for wide ranges of temperature. It is illustrated in Fig. 1 for some early data on 61ST tested at — 195oC, and in Fig. 2 for some recent data on copper at room temperature. The greater accuracy of the results of Fig. 2 over previous ones' is due to the equipment shown in Fig. 3. Three levers apply the bulk of the load, while the changes in the small remainder load are indicated sensitively by a low capacity load scale. Refs. 2 and 3 describe the recording equipment. A test like those in Figs. 1 and 2 provides the information necessary to determine the rate sensitizrity, n,4 of the metal. ( a log s ) ? log s n = ------------------------ ----------------------------= ( a logs e, ? log e logS2-logS1 log S2/S1 log i2 — log e1 log e2/e1 where S equals stress: e is logarithmic strain or natural logarithm of (final gage length/initial gage length);" i is strain rate or de/dt: and n is rate sensitivity, rate of change of log stress with log strain rate at a given strain, or (a log S/a log i),. Normally, the rate sensitivity, n, is positive, which means that an increase in stress causes an increase in rate. However, certain exceptions, attributed to strain aging,5 have been observed. Fig. 2 indicates how rate sensitivity values are derived from the measurements. Table I summarizes the rate sensitivity values derivable from Fig. 1. In contrast to the behavior of copper in Fig. 2, the aluminum alloy 61ST, which strain ages when tested near room temperature, exhibits an unusual transient when the strain rate is suddenly changed,' as shown in Fig. 4. Initially, there is a comparatively sudden vertical shift of the stress-strain curve in a direction corresponding to the rate change, but then the curve gradually shifts back again. The initial shift is not as sudden as might be expected, because the testing machine is unable to achieve the impressed rate change instantaneously, as illustrated in Fig. 2. The behavior shown in Fig. 4 will be referred to as a tensile transient, the word tensile implying that the behavior was observed in a tension type of test. The corresponding test, where the strain rate is maintained constant except for the sudden change, will be called a tensile transient test. A creep transient, by contrast, will be defined as a temporarily abnormal behavior in a creep transient test, where there is a sudden change from one constant load to another.' In Fig. 4, a naive look at the gradually decreasing and then increasing load after a sudden rate incre-

Jan 1, 1957

By AIME AIME

THE following paragraphs comprise such information as the Secretary has been able to obtain concerning the members and associates whose deaths have been reported. Further particulars or corrections of errors, and biographical data concerning deceased members or associates not already noticed in this way, are solicited. Pat Doyle was born in 1849. At the age of fifteen he entered the Civil Engineering College of Madras, India, and left it at seventeen, having achieved special distinction in mathematics, chemistry,. and geology. Before be was eighteen years old he was in charge of two of the most important Sub-Divisions in the Madras Presidency, where he had ample opportunities for acquiring a preliminary knowledge of his profession, which was his chief object in joining the Public Works Department. In 1867, his energetic measures saved the island of Seringham from disastrous inundation. At this period he began contributing to the press ; and after a varied practical experience he came into public notice again in 1876, with an article in the Colliery Guardian on Indian Mines and Mining. In 1877 he became a Fellow of the Statistical Society of London. He was a founder of the Straits Branch of the Royal Asiatic Society and a life member of the parent Society of Great- Britain and- Ireland, as well as a member of the Independent Asiatic Society of Bengal. In 1878-9 he was Chief Superintendent of the Public Works of Perak; was active in having the Associate Member Class added to the Institution of Civil Engineers; and became a member of the Society of Engineers of London and of the North of England Institute of Mining and Mechanical Engineers. In 1880 he went to the Southern Colonies and held several appointments in Australia, where he became a member of the Johnsonian Club, Brisbane, and the Queensland Philo-

Jan 5, 1908

By H. Rush Spedden, Arvid Thunaes

R. R. Knobler and F. E. Albertson—Following the testwork done by Thunaes and Spedden, a Sullivan deck plant was built for the Colquiri mill. This plant started to operate in April 1945 and continues in successful operation. Since May 1950 the Colquiri mill has operated with a completely revamped flowsheet at a rate of 1000 tons per day. The old Sullivan deck section was retained with this new flowsheet. The "slime plant" in Colquiri consists of one 12-cell Denver No. 18-Sp. Sub-A flotation machine, one 16-ft and one 12-ft hydroseparator, six five-deck Sullivan-frames and six shaking tables for cleaning up the Sullivan deck concentrates, as well as 12 Deister plus three Plat-O tables on which the fine sands, which are not treated on the S-decks, are concentrated. Only —325-mesh fines are treated on the Sullivan decks. The combined hydroseparator overflows are fed to the S-decks. From 1946 to 1949, i.e. with the "old" flowsheet and an average mill feed of 800 tons per day an average of 45 tons per day was treated on four Sullivan rougher frames. The two additional frames were used as cleaners. At times, up to 90 and 120 tons of slimes were treated successfully on this Sullivan deck installation. The average operating data for the S-deck section in Colquiri for the year 1949 were as follows: The tests reported in this paper indicated a tin recovery of 42 pct. The actual plant results for 1949 show a 54 pct tin recovery from the Sullivan decks. The total average quantity of tin produced from the S-deck section in 1949 was 15 tons of tin per month. This corresponds to 3 pct of the total mill recovery. The difference between the 6 pct overall recovery-increase expected after the tests in 1943 and the actual plant results given for 1949 is explained as follows. According to the tests, a total of 170 tons was expected to be routed to the Sullivan decks, but because of certain changes in the flowsheet and mill amplifications,

Jan 1, 1951

By H. Rush Spedden, Arvid Thunaes

R. R. Knobler and F. E. Albertson—Following the testwork done by Thunaes and Spedden, a Sullivan deck plant was built for the Colquiri mill. This plant started to operate in April 1945 and continues in successful operation. Since May 1950 the Colquiri mill has operated with a completely revamped flowsheet at a rate of 1000 tons per day. The old Sullivan deck section was retained with this new flowsheet. The "slime plant" in Colquiri consists of one 12-cell Denver No. 18-Sp. Sub-A flotation machine, one 16-ft and one 12-ft hydroseparator, six five-deck Sullivan-frames and six shaking tables for cleaning up the Sullivan deck concentrates, as well as 12 Deister plus three Plat-O tables on which the fine sands, which are not treated on the S-decks, are concentrated. Only —325-mesh fines are treated on the Sullivan decks. The combined hydroseparator overflows are fed to the S-decks. From 1946 to 1949, i.e. with the "old" flowsheet and an average mill feed of 800 tons per day an average of 45 tons per day was treated on four Sullivan rougher frames. The two additional frames were used as cleaners. At times, up to 90 and 120 tons of slimes were treated successfully on this Sullivan deck installation. The average operating data for the S-deck section in Colquiri for the year 1949 were as follows: The tests reported in this paper indicated a tin recovery of 42 pct. The actual plant results for 1949 show a 54 pct tin recovery from the Sullivan decks. The total average quantity of tin produced from the S-deck section in 1949 was 15 tons of tin per month. This corresponds to 3 pct of the total mill recovery. The difference between the 6 pct overall recovery-increase expected after the tests in 1943 and the actual plant results given for 1949 is explained as follows. According to the tests, a total of 170 tons was expected to be routed to the Sullivan decks, but because of certain changes in the flowsheet and mill amplifications,

Jan 1, 1951

By Warden A. Moller

(Pittsburg Meeting, March, 1910.) THE Fushun coal-field, now being opened up by the South Manchurian Railway Co., is connected with the main line by a branch, 30 miles long, from Sui Chia Tun, 10 miles south of Mukden, the capital of Manchuria. The coal-field, which lies on the southern bank of the Hun river, 25 miles east of Mukden, consists of a long narrow valley,. running east and west between hills composed of granitic and volcanic rocks. At the foot of the northern hills, the Hun river flows westward towards the Liao river, which drains the greater part of South Manchuria. At the foot of the southern hills, resting immediately upon volcanic rocks, and overlain by 20 ft. of alluvial, is a thick layer of Tertiary shales, carrying near the base two coal-seams. In many places the lower of these two seams is in immediate contact with volcanic lauds and basalts, the flows of which were evidently both prior and subsequent to the formation of the coal-seams. This contact has practically destroyed the lower seam for commercial purposes. The value of the field lies in the upper seam, which, for a length of nearly 8 miles, varies from 100 to 130 ft. thick. Of this seam, 85 per cent is good coal. The seam dips to the north conformably with the shales, at angles of from 25° to 30°, and appears to have an uninterrupted dip for about 1.5 miles before being possibly cut o$' by the northern hills. The coal-bearing shales extend east and west for a length of about 20 miles, but towards the east the continuity of the seams is broken by intrusive rocks. The coal is of the sub-bituminous variety, low in ash, bright in appearance, and breaks with a conchoidal fracture. It has the usual qualities of Tertiary coal-quick steam-raising and poor stacking-qualities. Pieces of resin, varying in size from

Apr 1, 1910

By R. S. McClellan

Western Talc Company, Inc., with headquarters in Los Angeles, Calif., has just completed an extensive modernization and expansion program at its talc mine near Tecopa, Calif., and at its talc and clay mills at Dunn Siding, Calif., the nearest rail shipping point to the mine. The basic objective of the program was to provide facilities necessary to produce 300 tpd of a wide range of ground talc and clay grades for the ceramic, paint, paper, rubber and other industries. In the planning of the program every effort was made to provide a system which would permit a high degree of quality control and uniformity of the finished products, along with efficient operation. Several years ago, R. T. Vanderbilt Co., Inc. purchased Western Talc Co. after a comprehensive investigation of its properties, including an extensive diamond drilling campaign. Western Talc's properties embraced a number of claims in the Resting Springs mining district in the northern part of San Bernardino Co. and the southern part of Inyo Co., Calif., some seven miles southeast of the town of Tecopa. Operations by the original company were started on a small scale in 1913 and production from that date to the time of purchase of the company by Vanderbilt is estimated at 250,000 tons. The major part of this output was sold to the ceramic wall tile industry.

Jan 3, 1968