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By P. Bolsaitis, L. Skolnick

A model of metallic solutions is postulated which explains the energy of formation of alloys on the basis of changes in electron density around solute and solvent atoms and changes in pairwise interactions between atoms. The model is based on the Wigner-Seitz cell model of metals, with the electronegativities of the metals as the parameter for the electron-attracting power of the constituent atoms. In contrast to models based on the description of cohesive energy in terms of pairwise interactions only, which require an empirical, adjustable correction parameter to the Berthe-lot relations in order to predict negative energies of formation, the electron cell model accounts for both negative and positive energies on the basis of parameters of the pure components. Calculated heats of mixing based on published parameters of the pure metals are found to compare favorably to experimental values, despite the absence of any adjustable parameters in the model. THE formulation of an "exact" quantum mechanical model for the energy of cohesion of metals reduces ultimately to the many-body problem and for a complete solution would require the knowledge of wave functions and energy levels of all the particles in the system. The case of alloys is further complicated by the fact that the potential fields around the constituent atoms are different and the matching of boundary conditions in terms of the resulting wave functions is still an unresolved mathematical problem. It appears that in spite of the numerous investigations that have led to an elucidation of many properties of the metallic state, the formulation of the Hume-Rothery rules in 1931 marks the lone accomplishment toward simple, qualitative prediction of the energy of formation of alloys. More recently Friedel'' and Arafa have utilized the modern concepts of the electronic structure in metals in combination with the Hume-Rothery rules to arrive at quantitative estimates of the energy of formation of alloys with low solute contents. The relative success of the Hume-Rothery rules and Friedel's and Arafa's studies encouraged broaching the subject of formulation of a model based on realistic physical parameters and of conceptual and mathematical simplicity that could be applied to alloys regardless of concentration. On the basis of the free-electron theory, the cohesive energy of pure metals can be expressed as a function of "valence" (number of free electrons per atom), lattice parameter (or density), and the ioniza-tion energy. In addition to the electronic contributions to cohesion, one has to consider the pairwise exchange interaction energy between neighboring ion cores and the contribution from van der Waals forces. The energy changes upon alloying are viewed as resulting primarily from a redistribution of electron densities around the ions (a simplification of the more basic concept of a change of the wave functions of the electrons in the presence of a perturbing potential field). In addition there is a change in the pairwise interactions between neighboring ions which is usually the only factor taken into account in commonly used adaptations of the quasichemical theory. The electronegativities of the metals forming the alloy are used as the measure of the electron-attracting power of the ions in the alloy and the difference in electronegativities as the driving force for changes in electron energy on alloying. The interplay of pairwise interactions and electronic forces results in positive or negative energies of formation of alloys. Results obtained for systems to which the free electron model is best applicable are in good agreement with experimental values. 1) COHESIVE ENERGY OF METALS IN TERMS OF THE ELECTRON CELL MODEL The simplest physical model of a metal is that of a lattice of positive charges immersed in a sea of uniform, negative charge distribution represented by the

Jan 1, 1969

By C. B. Alcock, L. I. Cheng

By the use of radiochemical methods for the study of the gas-liquid equilibria at low temperature, and for the determination of the sulfur contents of metal beads which had been equilibrated with H2S/H2 mixtures of known sulfur potential, it has been possible to obtain the liquid solubility and the free energy of solution of sulfur in liquid tin and lead at temperatures between 500°and 680°C. THE gas-liquid equilibrium method has proved in the past to be most successful in the determination of the thermodynamic behavior of dilute solutions of sulfur in liquid metals.1,2 One of the basic requirements for success with this method is that the volatility of both the metal and its lowest sulfide should be small, otherwise sulfide will be deposited at the cool end of the furnace, where it may react with the outgoing gases to form either sulfur-rich lowest sulfide or higher sulfides. The resultant value of the apparent equilibrium constant will then be lower than the correct one. This argument applies even at sulfur potentials below that in equilibrium with a separate condensed phase of the lowest sulfide at the reaction temperature, T. The mass of sulfide which is deposited at the cold end of the furnace, and hence the extent to which further reaction occurs with the outgoing gases, depends on the time taken for equilibrium to be reached between metal and gas. Since this will depend principally on the bulk of the metal phase which is used, one should clearly attempt to uie as small metal samples as possible. These considerations are important in the study of dilute solutions of sulfur dissolved in liquid tin and lead which both have moderately high vapor pressures as metals and form volatile sulfides. The limit on the size of the metal samples which may be used is set chiefly by the difficulties of analysis for very small amounts of sulfur. The oxygen or carbon dioxide combustion method, followed by iodimetric determination of the sulfur dioxide which is formed,has been found to be successful for the determination of small amounts of sulfur in copper, iron, cobalt and nickel.4 This method was unsatisfactory for sulfur dissolved in tin and lead, mainly because the sulfur dioxide was to some extent absorbed by the copious tin or lead oxide deposits which were formed on the walls of the combustion tube. Furthermore some of the sulfur was found to segregate on the surface of the beads as flaky sulfide crystals which would easily be lost in the transfer of a bead from a boat in the gas equilibration apparatus to one in the combustion apparatus. Oxidation in aqueous media to sulfate ion followed by precipitation as barium sulfate was, therefore, adopted as the analytical procedure. The gas-metal equilibrium experiments were all carried out with radioactive sulfur and thus the analysis involved the counting of barium radiosulfate. Furthermore the use of the radioisotope meant that the approach to the gas-metal equilibrium could be followed continuously by gas counting.' The metal beads were held separately in glass crucibles during equilibration and were transferred from the furnace to the beaker for dissolution in nitric acid still in the crucibles, and thus the possibility of sulfur loss by detachment of the sulfide segregates was eliminated. The temperature range of this investigation was 500° to 680°C. EXPERIMENTAL APPARATUS AND METHOD The apparatus consisted of two furnaces placed in series in a gas recirculation system, Fig. 1. One furnace F1, which was vertical was used to heat the alumina crucible, A, holding six metal beads in separate glass crucibles. The beads weighed between 300 and 700 mg each. The crucible assembly was introduced and removed from the furnace mechanically under a stream of oxygen-free argon. The other furnace, F2, was horizontal and was used to heat a cobalt Co9S8 mixture, held in an alumina boat, and made with radiosulfur containing about 1/2 millicurie per g of sulphur. This mixture, which was finely powdered, was used as a source of known H2S/H2 mixtures6 for a given furnace temperature. The recirculation system also contained a gas re-circulation pump (P), an end window Geiger-Miiller counter (N)—placed downstream of F1 so as to monitor the H2S pressure in the gas leaving this furnace— a sample volume for chemical analysis of the gas phase (G), gas drying tubes (D), filling taps and other standard ancillary equipment. The gas sampling volume was principally used in the cali-

Jan 1, 1962

By Frank Ruskey, Richard G. Burdick

Many problems associated with potential hazards in a proposed mining area may not be adequately appraised because of the complexity of trying to evaluate them in terms of production requirements. Frequently, encountered hazards have to be dealt with by day-to-day operational schemes that require the miner to either force a way through them or avoid them by blocking off the area in which the hazards are known to exist. These considerations, after the mine is in full production, can be costly to the mine operator and can increase the danger to the miners. A hazard-evasion computer program for mine planning that will appraise proposed mine layouts on the basis of existing or potential hazards has therefore been developed. The program is intended for use during the planning phase of a mine, where it should assist the mining engineer in making decisions in mine design, With the output from this program, the mining engineer should be able either to corroborate his judgments made on the basis of mining experience or to find unanticipated solutions to design problems. The program tests hundreds of possible solutions to a mining layout, and by sorting out the 10 best (based on a criteria of minimum-abandoned-coal) limits the number of choices that need to be considered and appraised for applicability to a given mine scheme.

Jan 1, 1976

The following list comprises the names of those persons who became members during the period Sept. 10, 1919, to Oct. 10, 1919. ADAMS, R. L Chief Min. Engr., Old Ben Coal Corpn., Mine 12, Christopher, Ill. Arizumi, Hiroshi The Kuhara Min. Co., Ltd., Tokyo, Japan. BAILY, T. F Pres. & Gen'l Mgr., Electric Furnace Co., Alliance, 0. BALDWIN, A. J., Min. Engr Box 145, Pikeville, Kentucky. BALTZELL, WILL H., Chief Engr., Canadian Steel Corpn., Ltd., Ojibway, Essex Co., Ont., Canada. BANON, E. MAGAWLY, Examining Engr., Dawes Bros., Inc. 108 So. LaSalle St., Chicago, Ill. BARNES, W., Mech. Engr., Excavating Dept., Ruston & Hornsby, Ltd., Lincoln, England. BASHORE, E. GORGAS, Head Chem., The Babcock & Wilcox Co., Bayonne, N. J. BASS, A. L Supt., Hobson Silver Lead Co., Ltd., Ymir, B. C., Canada. BORN, SIDNEY, Chief Chem., Empire Gas & Fuel Co. & Associated Companies, 1100 Cherokee Ave., Bartlesville, Okla. BRADLEY, J. G,, Coal Operator, Pres.,& Gen'l Mgr., Elk River Coal & Lumber Co., Dundon, W. Va. BENNETT, G. W., Min. Engr., Sales Engr., Taylor-Wharton Iron &- Steel Co., High Bridge,. N. J. BRUFF, CHARLES E., Member firm Bradley, Bruff & Labarthe, 85 Second St., San Francisco, Cal. COLLINS, FRANK W., Chief Engr., Bradley, Bruff & Labarthe, 85 Second St., San Francisco, Cal. CONNELL, F. M., Min. Engr., Eastern Alin. & Mill. Co., Ltd., 905 Bank of Hamilton Bldg., Toronto, Ont., Canada. CooK, HARRY H., Vice-pres., Valley Mould & Iron Corgn., 137 Shenango St., Sharpsville, Pa.

Jan 11, 1919

By Robert W. Hunt

When I had the honor of presenting to the Institute at the Buffalo meeting in October, 1888 (Trans., xvii., 226), my paper on " Steel Rails and Specifications for their Manufacture," I expressed my hesitancy in submitting my ideal rail-sections. Since then, continued residence in Chicago, perhaps, or greater intercourse with railroad officials, has either given me more courage or has taught me that so little is really known on the subject that one is safe in expressing one's views, let them be ever so erroneous. As a further personal excuse, I may remind you that " fools rush in," etc. At all events, I would now call attention to certain rail-sections which I believe to be good. I do not say they are the best, but I feel sure they have more merit than the majority of the adopted heavier-sectioned rails. In determining the proper form for a rail, the subject should be considered from two points; first, and most important, the duty required ; second, and of almost equal importance, the influence of existing details of manufacture upon the character of the finished product. It is perfectly proper that all the strains to which the rail will be subjected should be considered and calculated. But its ability to resist them will depend quite as much upon the character of the metal as upon the form of its section. That which would be the realization of the ideal with good steel would be disappointment with poorer metal. Therefore, the railroad engineer should always have in mind and pay due respect to what the metal worker may give him—the may being the factór of danger to be covered by his factor of safety, and possessing greater importance than any formula laid down by never so eminent authorities. It is well-known how positive is my conviction that high heat during manufacture and good rails cannot go together; hence, if we insist upon the avoidance of this evil by rail-makers, we must give them sections which can be made at low temperatures with commercial as well as technical success. The market-price for rails controls the practice of makers, and,

Jan 1, 1889

By NORMAN D. FitzGkrald

IN 1942 the outstanding characteristic of the petroleum industry was the multiplicity of war-induced distortions in virtually every segment of the business. So devastating was the success of the Nazi submarine campaign along the shores of the western Atlantic and on transoceanic routes that within six months after our entry into the war petroleum rationing was necessary in the East Coast area. The conquest of the Netherlands Indies by the Japanese three months after the opening of the war in the Pacific cut off our normal sources of rubber, and in our first year of war nationwide rationing of gasoline had to be invoked to conserve rubber-borne transportation facilities. Meanwhile the oil industry faced the imperative necessity for rapid expansion in the output of aviation gasoline and later accepted the vast responsibility for developing a new industry. synthetic rubber manufacture. Probably no other essentially peacetime industry has been forced to make so many complicated adjustments, yet its response to its wartime obligations has been nothing short of dramatic.

Jan 1, 1943

By AIME AIME

TUESDAY afternoon the annual meeting was devoted to a general session, in the auditorium, on production control. George Otis Smith presided and in opening the meeting recalled that the session in 1920 on the stabilization of the coal industry was the first time this subject had been discussed by Institute members in a general session and then introduced Carl Snyder, of the Federal Reserve Bank of New York, who spoke on "Long-time Growth and the Factors In Its Variations." He spoke without notes and a full presentation of his views must be deferred until the stenographer's report is available. He said that of the total production some 80 to 90 per cent represents goods for consumption and the other 20 to 10 per cent for construction. He discussed various indices of production, concluding that bank clearings are the best, and showed by charts that when they are plotted, allowing for various disturbing factors, they are seen to increase quite regularly at the rate of about 4 per cent per year. The production curve rises at only 3y2 per cent per year, because agricultural production does not in- crease as fast as manufacturing postal revenues in- crease at the rate of 5 per cent per year while the use of electricity increases twice as fast.

Jan 1, 1929

By J. W. Spretnak, G. W. Powell, J. H. Bucher

Tlze room-temperature tensile fracture oj smooth, round specitnens of three ultrnhigh- strength steels tempered to a wide range of strength levels was studied by means by light and electron-microscopic examination of the fracture surfaces. The fracture of AISI 4340 and 300 M at all the strength levels studied, and H-11, except after tempering at 1200° and 1300°F, occurs in three stages. The initiation of fracture is internal (except in some lightly tcmpeved specimers in which fracture is initiated at surface flaws), and is nucleated largely by separation at metal-second phase intevjaces. TIze voids grow and, coalesce to form a crack. When the crack has reached a sufficienl size, rapid propngutio~z ensues. Failure in this stage of fracture usually occurs by dimpled rupture of inicroshear stefis. In the case of H-11 tempered in the 1125° to 1300°F range, fracture in the shear steps is predominantly by concentrated deformation without void formation. The termination of fracture is usually occomplished by the formation of a shear lib in which fracture occurs by shear dimpled rupture. In the case of H-11 tempered at 1200° and 1300°F, no shear lip was obserued, and the radial elelments extend to the surface—a true termination slage does not exist. ThE tensile fracture of several metals and alloys has been investigated.2-4 In the case of polycrystal-line materials, cup-cone fracture usually results. The mechanism of cup-cone fracture may be summarized as follows.5 Cavities are formed in the necked region of the specimen. They usually are initiated by inclusions or second-phase particles. The cavities extend outwards by means of internal necking, and a crack lying about perpendicular to the length of the specimen is formed in the necked region. Subsequent crack growth occurs by the spread of bands of concentrated plastic deformation inclined at an angle of 30 to 40 deg to the tensile axis. Cavities are formed in the bands of concentrated deformation. The deformation bands zigzag across the bar with the net result that mac-roscopically the crack extends about perpendicular to the specimen axis. The final separation, or cone formation, appears to occur by continued crack propagation along one of the deformation bands out to the surface of the specimen. The micromechanics of the tensile fracture of ultrahigh-strength steels have not been thoroughly investigated. Larson and carr6,7 studied the tensile-fracture surfaces of AISI 4340 with a low-power microscope and reported that three stages of fracture could be observed in general. A centrally located region characterized by circumferential ridges, an annular region characterized by radial surface striations, and a peripheral shear lip were found. It was first pointed out by 1rwin8 that the central region is very probably one of fracture initiation and slow growth, and that the annular, radially striated region is one of rapid crack growth. Presumably the crack grows slowly, assuming roughly a lenticular shape, until it is large enough for the initiation of rapid propagation. In this investigation, it was attempted to determine the fine-scale aspects of the room-temperature tensile fracture of some ultrahigh-strength steels, and to relate the variation in fracture mode with microstructure. The steels studied were AISI 4340, 300M, and H-11 tempered to a wide range of strength levels. I) EXPERIMENTAL PROCEDURE The compositions of the steels studied are given in Table I. The steel was received in the form of hot-rolled bar stock 5/8 to 1 in. in diameter from which oversized specimens were machined and heat-treated. The heat treatments employed are given in Table 11. Subsequent to heat treatment, the specimens were ground to the final dimensions and stress-relieved by heating for 1 hr at 350°F (with the exception of the as-quenched steel). Standard smooth round specimens of 0.252-in. diameter and 1-in. gage length were tested in a Tinius Olsen Universal Testing Machine using a cross-head speed of 0.025 in. per min. The relatively coarse aspects of the fracture topography were determined by light-microscopic examination of sections through the fracture surface of nickel-plated specimens. A direct carbon-replication technique9 was used in the electron-microscopic study of the fracture surfaces. The replicas were examined in the electron microscope, and stereo pairs of electron micrographs were taken. The stereo pairs were then examined using a Wild ST4 Mirror Stereoscope. Carbide and inclusion particles extracted in the replicas were analyzed by selected-area electron diffraction. II) EXPERIMENTAL RESULTS The mechanical testing data are summarized in Table 111. The values reported are the average of

Jan 1, 1965

By Francis H. Crockard

During the past five years we have probably witnessed greater technological advances than in any similar period. Industry and science have steadily marched ahead. The makers of iron and steel products have watched with great interest the development of streamlined trains, faster and safer airplanes, the entirely new science of air-conditioning and the widespread use of stainless steels. Since 1930, we have witnessed the erection of the world's largest suspension bridge, the largest and fastest ocean liner and the spectacular Boulder Dam, while even greater things are planned in these particular fields. Other industries, too, have been moving ahead rapidly. This advance in a few years has been caused primarily by the fierce competition of the depression. Now, more than ever, is the emphasis placed upon quality and service. Makers of southern merchant pig iron have been no exception and have been confronted with increasingly strict chemical specifications and with much greater stress on physical characteristics than ever before. For example, sulfur in the iron must be held very low, competition demanding that it be in the 0.020's and low 0.030's; silicon content must be held within a very narrow range, and definite requirements of phosphorus and manganese are an essential part of the specifications. Physical characteristics are becoming of increasingly greater importance. The introduction of triple-skimmed, slow-cooled iron several years ago was the first step in this direction. Now there are a few customers who buy iron by chemical analysis and physical appearance, having found that the analysis alone is an insufficient guide to their requirements. In addition to questions of quality, the subject of cost has greatly altered the southern furnaceman's viewpoint on many things. Formerly we had low-grade but cheap raw materials, but recent developments, such as greatly increased labor rates, have raised the cost of the same

Jan 1, 1936

By Francis H. Crockard

During the past five years we have probably witnessed greater technological advances than in any similar period. Industry and science have steadily marched ahead. The makers of iron and steel products have watched with great interest the development of streamlined trains, faster and safer airplanes, the entirely new science of air-conditioning and the widespread use of stainless steels. Since 1930, we have witnessed the erection of the world's largest suspension bridge, the largest and fastest ocean liner and the spectacular Boulder Dam, while even greater things are planned in these particular fields. Other industries, too, have been moving ahead rapidly. This advance in a few years has been caused primarily by the fierce competition of the depression. Now, more than ever, is the emphasis placed upon quality and service. Makers of southern merchant pig iron have been no exception and have been confronted with increasingly strict chemical specifications and with much greater stress on physical characteristics than ever before. For example, sulfur in the iron must be held very low, competition demanding that it be in the 0.020's and low 0.030's; silicon content must be held within a very narrow range, and definite requirements of phosphorus and manganese are an essential part of the specifications. Physical characteristics are becoming of increasingly greater importance. The introduction of triple-skimmed, slow-cooled iron several years ago was the first step in this direction. Now there are a few customers who buy iron by chemical analysis and physical appearance, having found that the analysis alone is an insufficient guide to their requirements. In addition to questions of quality, the subject of cost has greatly altered the southern furnaceman's viewpoint on many things. Formerly we had low-grade but cheap raw materials, but recent developments, such as greatly increased labor rates, have raised the cost of the same

Jan 1, 1936

By Nick Holonyak

Halogen vapor-transport synthesis of Ga(As,-,Px) and its preparation into laser junctions are described. Electrical and optical properties of Ga(As,-,PX) laser junctions are discussed. The present limitations in these properties are related to material proble?vzs and the very early state of development of Ga(As,-,PX), and are discussed in this context. Inhonzogeneity problems, fluctuation of As :P ratio, and problems with deep-level contaminants are described and related to Ga(As,-,PX) junction performance. Laser junctions are demonstrated which operate to wavelengths as short as 6470 A (77°K). The prospect that Ga(As,-,P,) will operate to wavelengths perhaps 100A shorter is mentioned. IN this paper we wish to describe some of the more important features of almost 1 year of experience in the preparation and properties of Ga(As,-,P,) p-n junction lasers. Because much data so far available are far from complete, some of the results still must be considered tentative and subject to correction and revision as work on Ga(As,-,P,) crystal problems progresses. Although the electrical, optical, and device properties of Ga(As,-,P,) junction lasers are understandably of considerable interest, the work to date points out that by far the most serious problems extant and those deserving first attention are problems involving the growth, doping, and perfection of Ga(As,-,P,) crystals. One of the most formidable of these is to grow Ga(As,-,P,) sufficiently free of deep levels, either due to contaminants or to structural imperfections, to allow fabrication of laser p-n junctions which can be cooled and not suffer from "freeze-out" of carriers on deep levels (and consequent double-injection behavior). In addition to the problems of growing crystals adequately free of deep levels and generally of the highest perfection, so that the best possible laser junctions can be realized, the further goal remains of increasing the phosphorus content well beyond 40 pct in an attempt to determine the practical lower wavelength limits of laser action in the Ga(As,-,P,) system. Even though the laser junctions prepared in Ga(As,-,P,) are of importance in their own right, we have considered them at this point mainly a means to study the growth and crystal problems of the material. It can be concluded that the laser junctions now available are almost completely limited by the purity and structural deficiencies of Ga(As,-,P,) crystals, and cannot be fairly compared with, for example, GaAs p-n junction lasers until Ga(As,-,P,) crystal growth has been more extensively developed. The basis for the statements above will become evident in the following sections which describe Ga(As,-,P,) crystal and junction preparation, and laser-junction properties. G(As,-,P,) CRYSTAL GROWTH As previously reported,2 we have found it convenient to employ the halogen vapor-transport process3 for synthesizing Ga(As,-,P,) crystals for use in laser junctions. Commercially available GaAs and Gap, separately prepared by halogen vapor tranport, are sealed in the desired ratio in a quartz vessel with a quantity of column-VI donor and a small quantity of metal halide which supplies the halogen for transport. The sealed ampoule, as shown in Fig. 1, is heated at a temperature in the range from 1025" to 1100°C at the position of the source GaAs and Gap. The GaAs and Gap are simultaneously vapor-transported and deposited as Ga(As,-,P,) at one end of the ampoule

Jan 1, 1964

By R. W. Shoenberger, J. D. Clendenin, W. L. McMorris, N. Schapiro, B. R. Kuchta, A. A. Terchick, R. J. Gray, J. G. Price

INTRODUCTION * The United States is fortunate in having enormous reserves of metallurgical-grade coals. Although these coals are better in quality and more accessible than most coals found throughout the rest of the world, the best grades of these coals are being depleted. Consequently, more efficient exploration tools and techniques, such as advanced methods of core drilling and logging, correlation by palynology,** stratigraphy, paleontology and petrography are being used to help assess the extent and quality of the remaining coal reserves. Exploration and assessment of new and existing coal properties become of utmost importance in determining (1) the economic justification for mining the coal, (2) the optimum design of the preparation plant and (3) the most effective use of the coal. Fortunately, the cost of mining coal has remained stable because of better mine planning, more efficient operations and increased mechanization of mining operations. However, increased mechanization raises the amount of impurities in the coal mined, and this requires more and better coal beneficiation to meet the more stringent quality requirements set by the market. Besides, mechanical miners also produce relatively fine coal and, to ensure maximum liberation of impurities, much of the coal presently being used must be crushed to a finer size prior to preparation. The bulk of all coals presently used in this country is mechanically cleaned, much of it at a lower specific gravity than in the past. This necessitates the use of new and improved processes and equipment for coal washing and recovery, such as heavy-medium cyclones and vessels, and froth flotation cells. However, because wet-cleaning processes are pre- dominant in the United States and fine coal retains large amounts of moisture, the increased production of cleaned fine coal accentuates the need for new or improved methods and equipment for dewatering and drying this coal. The larger amounts of coal being beneficiated and the use of new and improved beneficiation processes will aid in controlling and ultimately eliminating sources of pollution. Modem coal markets demand coals that meet rigid specifications. Most coals are purchased under contracts that specify moisture, ash, and sulfur contents, or heating value, depending upon the end use. There has also been a growing trend toward specifying other properties, including particle size and coking capability. These specifications may include not only the * Editor's note: Because of the numerous and varied contributions of the associate authors of this chapter, the text does not differentiate between sections prepared by each individual as has been done in other chapters. ** Palynology is the study of plant microfossils, especially spores, pollen, and other types of fossils not usually studied by paleontologists.

Jan 1, 1968

By Messrs. von Jonstorff

Continued Discussion of the Paper of Messrs. von Jonstorff, Blair, Dillner and Stead, presented at the New York Meeting of the Iron and Steel Institute, October, 1904.* (Bethlehem Meeting, February, 1906.) CLEMENS C. JONES, Richmond, Va. (communication to the Secretary+) :-In the chapter of this paper entitled "Method for the Determination of Phosphorus," by Andrew A. Blair, a form of the reductor used by Mr. Blair is illustrated. This form was employed by me in my earliest experiments, and abandoned after my adoption of the final apparatus described in my paper on the subject in 1889. The results reported by Mr. Blair are very closely accordant; but my experience was that, in the use of this form, a loss of the solution, amounting to almost a cubic centimeter, was occasioned by minute bubbles of hydrogen rising to the surface, and there exploding. My final reductor was designed to prevent this loss; and the most satisfactory results were obtained with a reductor having the open cup replaced by a bulb-shaped receptacle, provided with a glass stopper, similar to that of a separatory funnel of similar capacity, as suggested in a foot-note in my original paper. In my experience, the use of this later form of reductor repeatedly gave duplicate results which were, coincident to the fourth decimal place. R. W. RAYMOND, New York, N. Y.:-The. remarks of Mr. Jones recall to my mind an interesting part of the history of the Institute, and, of its relation to modern progress in the department covered by this interesting and valuable paper. In

Mar 1, 1906

For the year ending February, 1920 PRESIDENT HORACE V. WINCHELL.. . MINNEAPOLIS, MINN. PAST PRESIDENTS PHILIP N. MOORE ST. Louis, Mo. SIDNEY J. JENNINGS NEW YORK, N. Y. FIRST VICE-PRESIDENT A. R. LEDOUX NEW YORK, N. Y. TREASURER GEORGE D. BARRON NEW YORK, N. Y SECRETARY BRADLEY STOUGHTON NEW YORK, N. Y VICE-PRESIDENTS CHARLES W. GOODALE,1 . . . . District 5 BUTTE, MONT. MARK L. REQUA,1 District 6 SAN FRANCISCO, CAL. HENRY S. DRINKER, District 2 So. BETHLEHEM, PA. ROBERT M. RAYMOND,2 . . . . District 0 NEW YORK, N. Y. EDWIN LUDLOW,3 District 2 LANSFORD, PA. A. R. LEDOUX,3 District.0 NEW YORK, N. Y.

Jan 11, 1919

By R. S. Busk

TWO groups of binary alloys were prepared. The first group consisted of those elements relatively soluble in magnesium: Li, Al, Zn, Ga, Ag, Cd, In, Sn, Hg, T1, Pb, and Bi. These are predominately Group B elements. The second group consisted of most of the remaining metallic elements, all of which are relatively insoluble in magnesium: As, Au, Ba, Ca, Ce, Cu, Ir, La, Mn, Ni, Pd, Pt, Rh, Sb, Si, Te, Ti, W, and Zr. These are all Group A, transition, or rare earth elements. Alloys of the first group were prepared by melting sublimed magnesium and elements as pure as obtainable in a graphite crucible, using a standard flux1 for protection. The melts were poured into a small graphite mold to produce 3xY4 in. diam slugs. Spectroscopic analyses were made of each slug. In all cases, the total impurity content was less than 0.05 pct. The slugs were then heat treated 5°C below the eutectic temperature until complete solution, as judged metallographically, was obtained. Filings from the center of the slugs were compacted at room temperature into 1/2 in. long x 1/4 in. diam cylinders, sealed in pyrex under 1/2 atm of purified argon, annealed at the heat-treating temperature for 1 hr, and quenched in water. After the X-ray diffraction patterns were made, each compact was analyzed chemically for the solute. It was found that the Mg-Li alloys reacted during filing to reduce the Li in solid solution. For this series of alloys, the slug was cold worked, annealed in purified argon, the surface dissolved in dilute HC1 to a depth of about 0.005 in., and the X-ray exposure made on the fresh surface. This procedure resulted in sharp, continuous lines and in true values for the lattice parameters. The alloys in the second group were prepared in the same way except that about 1 wt pct of each solute was added. Since the solubility limit was exceeded, not all the solute dissolved. These alloys were analyzed spectroscopically only to confirm the presence of the solute. The diffraction patterns were of the back-reflec-tion type using the characteristic copper radiation* and a flat cassette. Both the film and the specimen were rotated. The specimen temperature was maintained at 25" ± 1°C. The films had sharp lines; their diameters were measured directly to 0.01 cm. The parameters were calculated from the line diameters using a modified version of Cohen's extrapolation method.2 his method effectively eliminates systematic errors such as film shrinkage, inaccurate alignment, and non-precise film-to-speci-men distance. The random errors were minimized

Jan 1, 1951

By Johannes Moeljono, Werner Wenzel, Heinrich Wilhelm Gudenhau

As an important mechanism for increasing production of the suction-draft-sinter process, it has been shown that gas permeability through the sinter layer plays an important role. Methods to increase production rates have been indicated and suggestions for carrying out the process have been made to improve the rate of production, reduce the fuel consumption, and at the same time obtain a uniform sinter. Laboratory experiments were conducted at the Institute for Ferrous Metallurgy of the Technical University at Aachen to illustrate these methods. Methods of Increasing Gas Penetration Through Sinter Layers The following are of fundamental importance in determining the process cycle during the sintering of iron ores: 1) Generation of maximum temperature, since its form and range determine sinter quality. 2) Propagation velocity of the temperature maximum which controls the attainable output. 3) The convective heat transfer which influences the velocity of travel of the temperature maximum.

Jan 1, 1974

By D. J. Pye

Certain high molecular weight synthetic polymers in very dilute solutions decrease water mobility in porous media 5 to 20 times more than would be expected from the solution viscosity. This indicates that increasing water viscosity to reduce adverse mobility ratios in water floods is economically feasible in many situations. Laboratory results are consistent with accepted theory with respect to improved areal sweep, permeability distribution and displacement efficiencies as would be predicted from the solution mobility measured in the core. The laboratory results have been confirmed by field pilot floods which recovered 80 per cent and 100 per cent more oil than comparative water-flood pilots in fields containing 16 cp and 130 cp oil respectively. Economic analyses based on pilot data indicate the method to be profitable. INTRODUCTION The desirability of improving the water-oil mobility ratio in waterflood-ing operations has long been appreciated, especially for high viscosity crudes. Methods of reducing the oil viscosity by application of heat, gas resaturation and miscible drives have met with some success. Conversely, it has been generally conceded that increasing the water viscosity would also be effective, but the amount of thickening agent required to effect an appreciable increase in viscosity is discouragingly high. The use of such materials as glycerin, sugar, or glycols is completely out of the question economically, so that considerable attention has been given to the use of the much more efficient synthetic water-soluble polymers as viscosity improvers; but even these materials are not economically attractive. If increased water viscosity could be economically realized, marked improvements in areal sweep efficiency, as discussed by Caudle and Wittel and others, would be realized in field operations. Similarly, the improved mobility ratio would bring about increased recoveries by correcting permeability distribution problems as discussed by Stiles2 and Dykstra and Parsons,' and improvements in displacement efficiency would be obtained as recognized by Buckley and Leverett4 and Welge.5 LABORATORY STUDIES THE RESISTANCE EFFECT In the course of research to develop a more efficient water-soluble polymer viscosity builder, we discovered that a very few types of water-soluble polymers exhibited a most unusual and very interesting property not previously observed. Among the earliest materials showing such activity were polymers containing acry-lamide. Fig. 1 shows a typical plot of the solution viscosity vs concentration for one of these polymer solutions as determined in an Ostwald viscometer. As usual, such a plot is an approximate straight line on semi-logarithmic paper. Now, an inspection of Darcy's law, shows that a viscosity value can also be determined in a formation sample if the pressure, flow rate and permeability are known. If the core permeability is previously determined with wa- ter or brine, then the viscosity of another aqueous fluid may be determined from the equation. The viscosities so determined for glycerin (glycol or polyvinyl alcohol solutions, for example) agree with the viscometer determinations. However, in the case of the water-soluble polymer solutions in which we are interested, the viscosities measured in the formation sample depart very markedly from the viscometer values. A typical relationship for a polymer solution is also shown in Fig. 1. This unusual departure from the expected response is referred to as a resistance property of the polymer and is quantified as "resistance factor". Since the resistance factor R can best be determined in a core under study, the term has been defined on the basis of the ratio of the brine mobility to the polymer solution mobility at residual oil saturation so that:

Jan 1, 1965

By B. L. Averbach, Morris Cohen, L. L. Seigle

Free energies, enthalpies, and entropies of mixing of Ni-Au solid solutions containing 5 to 95 atomic pct Ni have been determined by the electromotive force method at 700° to 900°C. The thermodynamic activities exhibit large positive deviations from Raoult's law, and the entropies of mixing are almost twice those of ideal solutions. The enthalpies of mixing are positive (heat is absorbed) and are attributable to the lattice distortional energy resulting from the size difference between the nickel and gold atoms. This factor appears to be responsible for the miscibility gap at lower temperatures. IN the thermodynamic study of metallic solid solutions, most interest has been directed toward systems with negative deviation from Raoult's law, namely, those exhibiting superlattice or compound formation. The results of previous investigations are summarized in recent publications.'-' Relatively little experimental work has been carried out on solid solutions which manifest a positive deviation, possibly because the range of solubility in such cases is usually quite limited. Nevertheless, the relationship of the thermodynamic properties of these solutions to diffusion, nucleation, and precipitation in the solid state are of considerable importance. The binary Ni-Au alloys are particularly suited to an investigation of these relationships. Despite the presence of a miscibility gap at lower temperatures, Fig. 1, indicating a large positive deviation from Raoult's law, complete solid solubility is found above 840°C. Moreover, the difference in the atomic scattering powers of nickel and gold is sufficiently great to permit X-ray diffraction studies of atomic arrangements and pre-precipitation phenomena. Radioisotopes of both nickel and gold are available for diffusion work, and finally, a large difference in nobility between the two elements facilitates measurement of the thermodynamic properties. The present paper describes the experimental determination of the free energies, enthalpies, and entropies of mixing of solid Ni-Au alloys. Table I gives a list of the symbols used in the paper. Experimental Method The stability of nickel chloride relative to gold chloride" indicated that the galvanic cell method could be used for determining the thermodynamic properties of Ni-Au alloys. An electrolytic cell (Fig. 2) was constructed, similar to that of Weibke and Matthes,7 in which the electrodes were solid nickel and Ni-Au alloys, and the electrolyte was a fused mixture of alkali chlorides containing NiCl,. The cell electrodes were made from fine gold granules and carbonyl nickel shot melted together under argon, chill cast, swaged to 1/16 in. diam rod, and annealed for one week at 850°C. Commercial reagent and chemically pure grade salts, purified by dehydration, were used for the electrolyte. The cell, operating in an atmosphere of purified argon, was heated in a resistance-wound cylindrical furnace whose temperature was controlled to within ±0.5ºC. The potential developed between the pure nickel and the alloy electrodes, which is related to the thermodynamic properties of the alloys by standard equations to be presented later, was measured with a potentiometer and a mirror galvanometer sensitive to 10-7 v. Dehydration of the electrolyte was carried out in the assembled cell by evacuating at 100°C for about

Jan 1, 1953

By William E. Hughes, Roderick K. Davey

The objective of this chapter is to review and discuss interpolation techniques commonly in use in the mining Industry today, including simple examples. This chapter will not attempt to compare the relative accuracy of each technique as this subject has adequately been covered by several authors (Knudsen and Kim, 1967; David, 1974; and Barnes, 1979) When appropriate, methods will be compared relative to the results of simple examples and computational ease. The examples presented are based on metallic deposits. The techniques, however, are not restricted to metallic deposits and can generally be applied to nonmetallic ones. The purpose of interpolation, as applied to a mineralized deposit, 1s to extend the knowledge of the grade and geology of localized samples to an estimate of the grade and mineralogy of a larger block of ground or even an entire deposit. The word interpolation means to compute values between given values and is limited to that region between the known values. The distinction between interpolation and extrapolation is important and must be adhered to in the application of these techniques in general, the interpolation must be limited to the area enclosed by verified samples. The methods being discussed can be broadly broken into three categories. ( 1 ) geometrical methods, (2) distance weighting methods, and (3) geostatistical techniques.

Jan 1, 1979

The petition for the formation of a Tulsa Section was granted. The final budget for the year 1917, and the tentative budget for the year 1918, were adopted. The Secretary was instructed to continue to send the Bulletin to all members whose dues have been remitted on account of their being in the war service, but to hold the Transactions and send them on request to the address furnished for the purpose. The issues of the Bulletin were presented to the Federal Fuel Administration, at its request, with the compliments of the Institute. Fifty-nine Members, five Associates, and fifteen Junior Members were elected. The resignation of one member was accepted. The clues of four members who are on active duty at the front were remitted. An extension of time for the payment of clues was granted to four members, upon request.

Jan 2, 1918