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By E. L. Howard, R. S. Barney back

E. L. Howard (Chief Testing Engineer, Pacific Cement & Aggregates, Inc., San Francisco, Calif.) We have made concrete with all the materials mentioned by Mr. Barneyback, including sawdust. He has highlighted the principal problems and effects found when these light materials are used as concrete aggregate. We can only agree with the inter-relationship he has emphasized between grading, specific gravity and unit weight. Uniformity in these characteristics helps to assure good concrete. Mr. Barneyback says the design of lightweight concrete mixtures "is a complete mystery to most engineers". He is wholly right in his evaluation of our ability generally to put together a concrete using lightweight aggregate. A study of the references he has appended will yield little comfort in the matter of proportioning. Much remains to be done in this area of concrete. We believe Mr. Barneyback has treated the subject, though briefly, in an excellent manner.

Jan 1, 1965

By John F. Abel

Personal gain seems to be the most powerful incentive to economic progress. One of my first exposures to this phenomenon was the comparison between company stopes and leaser's stopes in a vein gold mine. The company stopes were 4 to 6 ft wide, whereas the leaser's stopes were so narrow that in some places one could not turn around. The company leased only that ground it felt was marginal to mine with day's- pay miners, but by skillful, careful and energetic mining, the leasers managed in most cases to make money for themselves and the company. The Hurting Truth This capitalist system, which puts a premium on successful risk taking, is under attack. Not that it hasn't been under attack all along. What hurts and angers us at this time is that the attack comes from the children of the system-its youth. Such blasphemy should, of course, be eradicated, root and branch. Or should it? Are we hurt in part because some of the things they say are true?

Jan 1, 1970

By G. R. Countryman, G. H. Thomas, I. Fatt

Procedures are described for scaling up turbulent friction pressure drops of inelastic fluids and laminar friction pressure drops of inelastic/elastic fluids in circular ducts. The laminar scale-up calculation method does not require the use of arbitrarily defined flow models, and can be performed directly from laminar capillary viscometry data, or by means of a numerical solution of the integral equation for Poiseuille flow, inputing true shear rate-shearing stress data from other simple shearing experiments. e.g. Couette and plane Poiseuille flows. The turbulent scale up procedure, based on the Dodge-Metzner correlation for inelastic fluids, requires evaluating the characteristic rheological parameters at the existing wall stress under laminar flow conditions. Since the wall stress is the quantity sought in a pipe flow scale-up problem, a trial-and-err or solution is indicated, and therefore a calculation method has been developed and programmed for a medium-size magnetic-drum-memory digital computer. Laminar flow data from other somces may also be adapted to this turbulent scale-upmetbod for inelastic fluids. Comparisons between predicted and experimentally observed friction losses for generalized Reynolds numbers ranging from 3 — 32.000 indicate an error band width of less than 10 per cent in circular tubes ranging in size from 0.5 to 1.89 in. in diameter. INTRODUCTION Considerable effort has been devoted to the problem of establishing an accurate procedure for predicting the laminar and turbulent flow behavior of non-Newtonian materials in pipes from data obtained with small scale laboratory or pilot plant equipment, as evidenced by the variety of reviews on the subject.1-3 Although there does not appear to be a universally accepted scale-up method for laminar flow, the various methods currently employed can be divided into two principal categories depending upon whether a functional relationship between shear rate and shearing stress is assumed, or whether a generalized correlation is adopted. The methods of Hedstrom4 and of Weltmann are typical of the first category, while the generalized correlation of Metzner and Reed6 illustrates the second category. Under appropriate conditions either approach yields a reasonably satisfactory description of laminar flow behavior. In contrast, the prediction of non-Newtonian transitional and turbulent friction losses is much more complex. For example, certain types of materials have been observed to sustain laminar flow at much higher flow rates than Newtonian liquids. When turbulence does develop, the level of agitation is damped to such an extent that the friction factor is lower than that of the original low viscosity Newtonian medium. Extremely broad transition regions and "diameter effects" have also been noted in the turbulent flow of certain chemically complex materials.' Aside from the latter complications, which are attributed in part to viscoelasticity, the existence of a variety of scale-up procedures for predicting transitional and turbulent friction losses is due principally to the chioce of viscosity parameter used in the definition of the Reynolds number. In contrast, Dodge and Metzner have demonstrated that the friction factorReynolds number relationship for inelastic fluids can be satisfactorily generalized provided the fluid property parameters are evaluated at the existing wall shearing stress.* However, the quantity usually sought in a pipe flow scale-up problem is the wall stress, and hence a trial-and-error procedure is required when dealing with non-power law materials. In this report we discuss two calculation methods: (1) for determining the wall stress, and hence the friction pressure drop, for inelastic fluids under conditions of turbulent flow by means of an iterative procedure, and (2) for predicting laminar friction pressure drops without recourse to arbitrarily defined flow models.

By G. K. Burgess

THE question of the allotropy of iron, in spite of a vast amount of experimental work and perhaps an even greater amount of theorizing, is not yet settled. That there is a definite transformation in iron near 900,° the A3 point, is generally recognized, as well as the fact that the temperature of this transformation is lowered by the addition of carbon and metallic elements. On heating, the transformation Ac3 is always found at a higher temperature than the transformation on cooling, Ar3. Whether the A3 transformation is sharp like the melting point of a pure substance, or extends over a considerable range of temperatures, embracing perhaps as a lower limit the A2 change, appears to be still an open question for pure iron. The nature and identity of the A2 transformation, it would appear from recent publications, has not yet been satisfactorily settled. In the present paper a critical, historical summary is given of the experimental investigations of the location of A2 and A.3 in pure iron, together with brief mention of some of the theoretical aspects of the subject, and an account is given of a series ?of experiments carried out with several samples of very pure iron which were studied by two methods of thermal analysis in the range from 5000 C. to 1,000° C., and which it is believed furnish a contribution of considerable interest as to the location and nature of the A3 and A2 transformations. Great attention has been given to the details of experimental manipulation and to the preparation of the samples, as it was soon found that some of the discrepancies noted in the work of many experimenters may be traced largely to lack of precautions which we have found essential. For example, to anticipate somewhat, it is necessary to provide a suitable practically gas-free furnace, the heating and cooling of which may be regulated to a nicety. To render a minimum the deforming effects on the cooling and heating curves of the poor conduction of the sample, it must be of a form and mass to pass on its heat rapidly and completely to the thermocouple; and finally the sample itself must be freed from gases which, if present, further mask the definiteness of the heating and cooling curves. We, have also varied within wide limits the several factors which may influence the determination of the exact location and shape of the transformation ranges, especially the mass and preparation of sample, rate of heating and cooling, design of furnace; and finally, as nearly as it is experimentally possible, we have worked with a substance approaching pure iron, free from occluded gases and other impurities, and contained within a vacuum.

Jan 10, 1913

By F. H. Spedding

From thermal, metallographic, X-ray, dilatometric, and electrical resistance data a Phase diagram is proposed for the La-C system. TWO compounds are formed, body-centered-cubic Laz C, having a large range of solid solubility, and body -centered-tetrago-nal Lac2 . The former melts incongruently at 1415°C, and at 25OC it has an electrical resistivity about two and one-half times that of bure lanthanum. The latter melts congruently at 2356°C and at room temperature has an electrical resistivity about equal to that of bure lanthanum. The addition of carbon to La lowers the melting Point of La about 115' C, raises the higher (B-Y) transfomzation about 10" C and appears to have no effect on the lower ( a-0) transformation. The addition of carbon appears to lower the oxygen content in the metal and improve the machinability; however, the tendency to oxidize is increased. Two eutectics are formed in the system. The first occurs at 2.2 pct C and melts at 806" C, while the second occurs between Lac2 and C with a melting point of2271"C. PETTERSSON,~ in 1895, was the first to prepare lanthanum dicarbide by heating the oxide with carbon in an electric furnace. He showed that this yellow, crystalline but brittle carbide had a formula corresponding to LaCz and that it reacted with water with the evolution of hydrogen and hydrocarbons and the formation of the hydrated oxide. Von Stackelberg's investigation of the crystal structure of the MCz carbides showed that the lanthanum dicarbide is of the tetragonal calcium dicarbide-type structure. He found the lattice parameters were a = 3.92 and c = 6.56.* Bredig,' using X-ray methods, showed that the room-temperature form of lanthanum dicarbide is stable up to 1750 °C and that above this temperature it transformsoto a face-centered-cubic structure, a = 6.0 ± O.lA, probably of the pyrite, FeSzstruc- typ? The reported discovery of two new cerium carbides, suggested that a corresponding face-centered-cubic lanthanum monocarbide and a body-centered-cubic lanthanum sesquicarbide might exist. This paper describes work on the lanthanum-carbon system which is part of a study of the rare earth metals and their alloys now in progress in this laboratory. EXPERIMENTAL PROCEDURE Source of Materials—The lanthanum metal was prepared at the Ames Laboratory by metal1o;hermic reduction of the fluoride with calcium metal. The results of spectrographic and chemical analysis indicated the presence of 0.01 pct Y, Al, Cu, Fe, and Si; 0.02 pct Ca and Mg; 230 ppm C; and 115 ppm N. The carbon used was of two types: 1) "National Special Graphite Spectroscopic Electrodes," and

Jan 1, 1960

By F. W. Schremp, V. L. Johnson

This paper discusses the results obtained from high temperature, high pressure filter loss studies in which field samples of clay-water, emulsion, and oil base fluids were used. High temperature, high pressure tests of some premium priced emrilsion and oil base drilling fluids show filter loss peculiarities that are not predicted by standard API tests. It is recommended that high temperature, high pressure filter loss tests be used to evaluate the performance of such fluids. Apparatus is described which proved to be satisfactory for evaluating filter loss behavior over a wide range of temperatures and pressures. INTRODUCTION The petroleum industry spends large sums of money each year on chemical treating agents for lowering filter loss and on premium-priced low filter loss drilling fluids. While it is an accepted fact that low filter loss is advantageous during drilling operations, it is questionable whether the present standard method of determining filter loss gives a reliable indication of the loss to he expected under bottom hole conditions. The purpose of this paper is to show that high temperature. high pressure filter loss tests Should be used to evaluate filter loss behavior of fluids for deep drilling. Concern over possible effects of filter loss on oil well drilling and well productivity dates back to the early 1920's. During the years 1922 to 1924, filtration studies were reported by Knapp,' Anderson2 and Kirwan." These studies were the first to be reported in the literature on this subject. No further information was published on the subject until 1932 when Rubel' presented a paper in which he discussed the effect of drilling fluids on oil well productivity. In 1935. .Jones and Babson constructed the first laboratory tester designed to study the effects of temperature and pressure on the filter loss behavior of clay-water drilling fluids. In a discussion of their investigations, Jones and Babsons stated, "Performance characteristics of a mud can he evaluated with considerable reliability by a single test at 2,000 psi and 200°F. Exact correlation between the results of performance test5 made under these conditions and the behavior of muds in actual drilling operations is of course impossible." Jones arid Babson apparently were well aware that at best laboratory tests can give only qualitative answers to the question of what is the actual behavior of a drilling fluid when subjected to deep drilling conditions. Jones' presented a paper in 1937 in which he described a static filter loss tester to be used for routine filter loss tests. This instrument subsequently was adopted as the standard APl filter loss tester. In 1938, Larsen7 developed a relationship between filtrate volume and filtrate time that is in general acceptance today. Larsen was cognizant of the danger of estimating bottom hole behavior from filter loss measurements at room temperature. He tried to predict the effect of temperature on filter loss by relating temperature effects through the temperature dependence of filtrate viscosity. This was undoubtedly an over-sirriplification of the temperature dependence of drilling fluid filter loss. In 1940, Byck" published a summary of experimental results of filter loss tests made on six representative California clsy-water drilling fluids. He concluded that "no existing method will permit even an approximate determination of the filtration rate at high temperature from data at room temperature. It is necessary to measure filtration at the temperature actually anticipated in the well, or to make a sufficient number of tests at various lower temperatures so that a small extrapolation of these data to the anticipated well temperature may be applied." Byck's findings were presuma1)ly well accepted and recognized by drilling Fluid technologists, and yet, they did not lead to wide adoption of high temperature drilling fluid filtration equipment. This is evidenced by the fact that no addition information has appeared in print on the subject since 194). Study of Byck's data shows that there was a useful consistency in them. The fluids did not show predictable losses at high temperatures, but they did line up at high temperatures in approximately the same order that they lined up at low temperatures. That is, if a fluid appeared to be a good fluid with relatively low loss at low temperatures, it would also be a good fluid with relatively low loss at high temperatures. In the last decade. the above situation has changed. The drilling fluid art is markedly different from what it was. The outstanding change, as far as the present discussion is concerned, has been the adoption of wholly new types of drilling fluids. Oil base and emulsion drilling fluids have come in to wide use. It is, therefore, necessary- to re-examine previously satisfactory generalizations to see if they are still valid. It turns out. as might have been expected. that Byck's explicit generalization. already quoted, is still true. Filter losses at high temperatures cannot be predicted from filter losses at low temperatures. However, no further generalizations are valid now. Fluids of different chemical types show different general behaviors. No longer do the fluids line up approximately the same at high temperatures as they do at low temperatures. They may line up entirely differently. Special fluids exhibiting very low loss at low temperatures may have losses as high as those of ordinary clay-water fluids at high temperatures. This fact is highly significant, because premium prices are being paid for the special fluids.

Jan 1, 1952

By Herbert A. Stein, John B. Murdock

AN analysis of perlite expansion furnaces must be based upon one consistent theory which explains how and why perlite does expand when heated. There is more than one such theory, so to establish a basis for the rest of this paper, the authors will outline one theory and the data that support it before going into the construction details of different furnaces. JOHN B. MURDOCK, Associate Member AIME, is President, and HERBERT A. STEIN is Secretary, of the Perlite Corp., Phoenix, Arizona. San Francisco Meeting, February 1949. TP 2736 H. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Jan. 3, 1949. Why Perlite Expands: Perlite is known to contain some dissolved or combined fluid, probably water, which is lost when the material is heated to fusion. It is generally agreed that when particles of this volcanic glass are heated to fusion in such a way that vaporization of this water into steam takes place at the same time as the glass becomes soft, the steam puffs up each particle into a mass of glass foam. It is a simple matter to expand perlite under a blow torch for demonstration purposes, but in commercial installations, the problem is made more complicated by the necessity of making efficient use of both raw material and fuel, and producing an expanded aggregate conforming to close specifications for size distribution and density, using many different types of perlite rock. The ability of a given operation to fulfill these requirements depends upon the proper handling of four variables. They are: (1) the nature of the perlite rock used, (2) the heating time taken to get the perlite particle up to its highest temperature, (3) the size of the particle, and (4) the maximum temperature the particle reaches. Types of Perlite Rock: Perlite may be classified in many ways, but the characteristics most easily correlated with its behavior in furnaces are its softening temperature, its effective water content, and its "liveliness." Actually there is a close correlation among these three characteristics so it is possible to describe a perlite using any one of them. Lively perlites always have low softening temperatures and high effective water contents, whereas the deader perlites have higher softening temperatures and lower effective water contents. These softening temperatures run from 1400°F to above 2000°F and the effective water contents run from over 2 pct down to 0.2 pct. Included in the category of lively glasses are the green pitchstone from the Edgar claim in Superior, Ariz., the red pitchstone on the Animas highway south of Lordsburg, N. Mex., and a gray glass from Beatty, Nevada. Examples of intermediate perlites (in order of decreasing liveliness) are the Guzman-Lobb perlite with obsidian

Jan 1, 1951

By Herbert A. Stein, John B. Murdock

AN analysis of perlite expansion furnaces must be based upon one consistent theory which explains how and why perlite does expand when heated. There is more than one such theory, so to establish a basis for the rest of this paper, the authors will outline one theory and the data that support it before going into the construction details of different furnaces. JOHN B. MURDOCK, Associate Member AIME, is President, and HERBERT A. STEIN is Secretary, of the Perlite Corp., Phoenix, Arizona. San Francisco Meeting, February 1949. TP 2736 H. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Jan. 3, 1949. Why Perlite Expands: Perlite is known to contain some dissolved or combined fluid, probably water, which is lost when the material is heated to fusion. It is generally agreed that when particles of this volcanic glass are heated to fusion in such a way that vaporization of this water into steam takes place at the same time as the glass becomes soft, the steam puffs up each particle into a mass of glass foam. It is a simple matter to expand perlite under a blow torch for demonstration purposes, but in commercial installations, the problem is made more complicated by the necessity of making efficient use of both raw material and fuel, and producing an expanded aggregate conforming to close specifications for size distribution and density, using many different types of perlite rock. The ability of a given operation to fulfill these requirements depends upon the proper handling of four variables. They are: (1) the nature of the perlite rock used, (2) the heating time taken to get the perlite particle up to its highest temperature, (3) the size of the particle, and (4) the maximum temperature the particle reaches. Types of Perlite Rock: Perlite may be classified in many ways, but the characteristics most easily correlated with its behavior in furnaces are its softening temperature, its effective water content, and its "liveliness." Actually there is a close correlation among these three characteristics so it is possible to describe a perlite using any one of them. Lively perlites always have low softening temperatures and high effective water contents, whereas the deader perlites have higher softening temperatures and lower effective water contents. These softening temperatures run from 1400°F to above 2000°F and the effective water contents run from over 2 pct down to 0.2 pct. Included in the category of lively glasses are the green pitchstone from the Edgar claim in Superior, Ariz., the red pitchstone on the Animas highway south of Lordsburg, N. Mex., and a gray glass from Beatty, Nevada. Examples of intermediate perlites (in order of decreasing liveliness) are the Guzman-Lobb perlite with obsidian

Jan 1, 1951

By Dennis Peterson

INTRODUCTION The business arena has dramatically changed for most producers and consumers of commodities. International debt, currency shortages, political upheavals, etc., require corporations today to be sophisticated and flexible enough to change their purchasing and sales techniques in order to maximize returns. Many external factors, such as interest rates, trading partners, currency changes, and government edicts, can have an adverse effect on a company's bottom line. Totally out of a company's ability to control or predict, these. factors force the commodities based corporation to constantly re-evaluate its operating scope and domain. The principle of back-yard only operations and the laissez-faire with blinders style of management is no longer a viable way to run a business. The industrial world has been operating for the past 10 to 15 years as though there were no commodity nor raw material crisis. For developed countries the primary products sector has become marginal, whereas it was central in the first half of the century. A radical change in the method of doing business is necessary to offset a depression in the industrial economy. The risk of collapse may be heightened by a banking crisis caused by massive defaults on the part of commodity producing debtors, whether in the third world or in our own farm producing sector. The raw materials economy has become divergent with the industrial economy. This is a major change in the world economy with tremendous implications in both developed and developing countries for economic and social policies and economic theories. Basic competition issues, such as low labor costs, are likely to become less of an advantage in international trade. In developed countries these costs are going to account for a smaller portion of total costs. The total costs of automated processes are lower than those of traditional plants with low labor costs. Automation in the commodities sector eliminates the hidden but high cost of not processing at capacity created by poor quality, rejects and maintenance for product change-overs. The cost of capital will become increasingly important in international competition. Over the last ten years the U.S. has become the highest cost country in this area. Reversing the U.S. policy of high interest rates and costly equity capital should be a priority for management decision makers. In the rapid industrialization of this century, Japan developed by exporting raw materials, (principally, silk and tea), at steadily increasing prices. Germany developed by leap frogging into the high-tech industries, mainly in electricity, chemicals and optics. The United States did both. Both avenues are blocked for today's rapidly industrializing countries because (a) the deterioration of the terms of trade for primary products, and (b) it requires an infrastructure of knowledge and education far beyond the scope of a poor country. Many explanations exist for the explosion of international money flows. The shift from fixed to floating exchange rates in 1971 may have given initial impetus by inviting currency speculation. The surge in liquid funds flowing to petroleum producers after the oil shocks of 1973 and 1979 was definitely a major cause. There can be little doubt that the U.S. government deficit also played a big role. The American budget deficit has become a massive void, sucking in liquid funds from all over the world and making the U.S. the world's major debtor country. In reality, a trade and payments deficit is actually a loan from the seller of goods and services to the buyer, that is, to the U.S. From now on, the global ramifications of business will have to be treated in economic theory and business policy alike. Economic theory teaches that the comparative advantage factors of a real economy determines operative and financial policy. These comparisons -- labor costs, productivity, raw materials cost, energy costs,

Jan 1, 1990

By A. L. Mular

The flotability of crushed zinc oxide pellets which were doped to produce more n-type or less n-type (more p-type) properties was studied with a Halli-mond tube. Flotation data are presented to show that the pH at which 50% recovery occurs and the collector concentration for 50% recovery depends upon the concentration of doping agent added substitu-tionally for zinc in zinc oxide. The time of sintering of pellets has a slight effect on flotation behavior. A speculative model is proposed to explain the observed behavior in light of the fact that zinc oxide is a semiconductor and has a space charge region at the surface. Experimental verification is necessary before the proposed model can be established as correct. In recent years, the attachment of flotation reagents to minerals has been shown to depend upon the behavior of an electrical double layer which exists in the liquid near the mineral-liquid interface.' Thus, a mineral placed in water will undergo a surface re-arrangement, most likely be preferential dissociation of lattice atoms or by surface adsorp-tion-desorption reactions, to form a dissociation electrical double layer with the solution. Among the many factors which influence adsorption processes, the past history of the mineral itself is one of the most important. Because of trace impurities, minerals from different localities may exhibit marked differences in flotation behavior. This is not unexpected, since investigators who have studied the detailed structure of the double layer's3 have known for some time that the impurity content of many minerals may exert strong influence on double layer variables. For this reason, their studies were usually made with minerals of high purity. The precise relationship between impurities in a mineral and double layer parameters such as capacity and electrostatic potential has been obscure. However, impurities in a semiconductor type mineral which is in contact with a solution have been recently shown to produce changes in the properties of a space charge layer which extends into the bulk of the semiconductor to a distance of one micron or more.4 The double layer is influenced by the space charge layer, whose origin is best discussed in terms of the band theory of solids. A qualitative description of the behavior of impurities in the bulk of a semiconductor, from a chemical point of view, is useful at this point. Briefly, impurities or defects (lattice vacancies, interstitials, etc.) in semiconductors such as PbS, ZnS, FeS2, Cu2S, NiS, NiO, Fe2O3, ZnO, CdS, MnO2 and many others, behave somewhat like acids or bases in water. For example, water dissociates into hydrogen and hydroxyl ions according to

Jan 1, 1965

By K. L. Sehgal

Minerals are the basis of modern civilization: their exploitation and effective utilization are a yard- stick for measuring the comparative prosperity of different nations. This is particularly true in India where industrialization is just beginning to pick up speed. Production targets for our Fourth Five Year Plan (1966-71) are far ahead of the figures for, say, 1950 (the year we won independence) and show the extent of the expansion. Many problems remain to be solved, not least of which is the shortage of raw materials. India is no novice at utilizing minerals. Archaeological ruins at Harappa and at other historical places in the country show evidence of the fact that the ancient Indians not only knew the art of winning minerals from the ground over 6000 years ago-they were also well acquainted with metallurgy. Some of the present sites of mineral exploitation are the same as those our ancestors worked for many centuries.

Jan 9, 1965

By S. W. Miller

During the examination of welds made in steel by the oxy-acetylene and electric-arc processes, the writer has met with some unusual structures, which he has not encountered elsewhere. They seem to be quite closely associated with the welding methods used, and characteristic of them, and would seem to be worth noting, especially as the references to them in the literature are few, and their explanation not clear or complete. An introductory word or two about fusion welding may not be out of place. The oxy-acetylene process is based on the great and very local heat generated by the burning of acetylene in the presence of commercially pure oxygen, the two gases being thoroughly mixed before combustion. The theoretical temperature is somewhat under 4000" C, but on account of various losses, the actual maximum temperature is probably about 3000" C.' The electric-arc process, using a metal electrode, which is also the filling rod, generates a still higher and more local temperature. The actual temperature of the positive crater of the carbon arc is given as 3500" C.2 NO figures have been found for the temperature of the arc using a metal electrode, but it would probably not be very different from that of the carbon arc, and probably higher than that of the bxy-acetylene flame. The greater localization of the electric arc is due to the fact that it is not surrounded by a large envelope flame, as well as to its higher temperature; while the oxy-acetylene white cone, or welding flame, in which the carbon of the acetylene is burned to CO, is surrounded and preceded by a long envelope flame, itself of quite high temperature, in which the CO is burned to GO2, and the hydrogen of the acetylene to H2O. This flame spreads around and over the pieces being welded, heating them to a further distance from the weld than does the electric arc.

Jan 1, 1918

By Rex B. McLellan

Studies of the eyuilibrzum between ferrite and austenite with gas mixtures (CO + CO2 and H2 + CHe) have been used as a means of deducing the energy and vibrational entropy of carbon atoms in dilute interstitial Fe-C solutions. A simple model for dilute interstitial solutions is given which enables a solubility equation for the equilibrium between the gas mixtures and the solid to be deduced. This solubility equation is used to estimate the partial In this work measurements of the equilibrium between dilute solid solutions of carbon in iron and gaseous mixtures of CO2 + CO and CH4 + Hp have been analyzed using theoretical solubility equations deduced from a knowledge of the thermodynamic parameters of the gas mixtures and an appropriate model for the solid solution. The solubility equations are deduced by equating the chemical potential of carbon atoms in the gas thermodynamic functions of dilute Fe-C solutions from the measured equilibrium between the solid and the gas mixtures. It is shown that the vibra-tional entropy of a carbon atom in a and y iron is smaller than the corresponding entropy 01. a nitrogen atom in solid solution inferrite or austenite and that there is little difference between the vibrational entropies of both nitrogen and carbon atoms in ferrite and austenite. and solid phases. The chemical potential of carbon in the gas is found from a simple statistical mechanical analysis of the gas mixtures utilizing spec-troscopic data while that for carbon in the interstitial solution is found from a model in which the carbon atoms act as bound oscillators distributed in a random fashion in the solution. The solid solution is dilute enough to enable solute-solute interactions to be ignored. Thus the configurational entropy of the solution is ideal but the mixing entropy contains additional excess terms due mainly to the vibrational changes occurring on solution formation. The partial excess entropies (and the partial energies) do

Jan 1, 1965

By M. W. Cox, V. F. Hollister

EXPLORATION for metallic mineral deposits is carried on by those special adaptations of methods which the explorer believes will yield most economically or satisfactorily the particular answer sought. In this project the usual methods of geologic observation, recording, and interpretation, when combined with magnetic geophysical methods and geochemical soil sampling, led to disclosures of appreciable zinc mineralization where none was visible in surface exposure. Since 1945 considerable work has been done with geochemical prospecting methods, chiefly in determining the presence and distribution of various elements existing in minor amounts in rocks, soil, vegetation or waters of mineralized areas. Such work, in which the U. S. Geological Survey has taken the lead, finds a ready place in the field repertoire of the exploration geologist as a supplement, not a substitute, for other methods. The Chollet project was carried out in 1951 by the American Smelting & Refining Co. near its Van Stone mine in northern Stevens County, Wash., in the area shown in Fig. 1. The Van Stone mine is located in the Onion Creek drainage of the Selkirk Mountains, midway between the towns of Colville and Northport, Wash., and some twenty airline miles west of the Metaline mining district. Its zinc-lead orebodies, currently yielding about 1000 tpd of ore, occur as bedding replacement deposits in the middle Cambrian Metaline formation near an intrusive granodiorite contact. The target of exploration at the Chollet prospect was a similar geologic environment along the intrusive contact about 5 miles west of the mine. Geographic Setting The Chollet ground covers a north-facing slope at 3000 to 4000-ft elevation. Second-growth jack pine and tamarack with some hemlock and yellow pine make a thick forest cover. A heavy under-forest of alder, willow, and lesser shrubs occupies the draws, see Fig. 2. Grassy slopes appear at higher elevations. The lower slopes are underlain by a thick blanket of glacial till and alluvium so that outcrops are scarce; however, perhaps 50 pct rock exposure prevails at higher elevations. This part of northern Washington annually receives about 25 in. of precipitation, which largely falls as snow in the winter months. Summers are dry with occasional rainy periods. General Geology The Van Stone mine and the Chollet prospect lie along the southern margin of a westerly extending lobe of the Kaniksu batholith, one of the series of granodioritic masses that are intrusive into Cretaceous and older rocks in northern Washington and southern British Columbia. The margin is composed of complexly deformed Paleozoic sediments ranging in age from the lower Cambrian Maitlen phyllite on the east, through middle Cambrian Metaline formation (limestone and dolomite), to Ordovician Ledbetter slate on the west. In general the formations strike N10 to 50E and dip steeply northwestward, although dip reversals and minor folding occur. This general rock distribution is shown on Fig. 3. In this area the Metaline formation, which is the host rock for mineralization, appears to be of about 4000-ft thickness that can be conveniently divided into the same three units defined by Park and Cannon' for the Metaline area. The basal part consists of 1000 ft of interbedded white limestone, argillaceous limestone, and gray silty argillite. The middle part, approximately 1500 ft thick, consists of fine-grained black, gray, and white dolomite. This unit also contains minor interbedded limestone. The upper part is a gray massive limestone about 1500 ft thick that grades upward into slaty limestone and slate capped locally by a thin black jas-peroidal dolomite which is either the uppermost member of the Metaline formation or the basal member of the overlying Ledbetter (Ordovician)

Jan 1, 1956

By Charles Burgess

THE improvement, in the quality of cast iron by means of alloy additions has been a metallurgical accomplishment of recent years. Work in this field has shown that chromium is one of the most effective of such additions but, in general, the influence of chromium has been studied only in. connection with other alloying additions, with irons other than foundry irons, or with relatively high percentages of chromium. The present study was initiated for the purpose of determining the influence of small additions of chromium (0.25 to 1.00 per cent) on the quality and resultant properties of cast irons of various foundry grades. The effect of small chromium additions on cast iron was investigated with particular reference to casting characteristics, hardness vs. section, strength, machinability, heat resistance and structure. MATERIAL TESTED Three separate types of cast iron were investigated as to the effect of small chromium additions. The first series of these irons was prepared from remelted foundry cast iron at the Union Carbide and Carbon Research Laboratories, and the other two -series consisted of cupola melts made under usual operating conditions. The first series was made by melting 30-lb. charges of foundry scrap iron containing - 2.86 per cent carbon, 2.72 silicon, 0.50 manganese, 0.062 sulfur and 0.794 phosphorus in a carbon resistance furnace. The chromium was added as high-carbon ferrochrome just before pouring. The irons were cast at approximately 1250° C. (2282° F.). The analysis and physical properties of these irons are given in Table 1, test 1. The second set of cast irons was made in a cupola in accordance with normal practice, 'the charge containing approximately 42 per cent steel scrap and the chromium additions being made to the ladle. Analysis and tests of these heats are shown In Table 1, test 2. A small amount of copper was present in heat C of this series.

Jan 1, 1932

By Zdzislaw Specht

This paper discusses elementary laws pertaining to seismic reflection methods and presents a general and simple criterion for determining the direction of dipping of a reflection horizon from observational data of distance and time. The important development of practical geophysics and the successful results obtained in America, Germany, and other countries, caused introduction of geophysical methods of prospecting in Poland. Of all methods, seismic prospecting has proved most successful in the area of the Carpathian foreland, where new oil reserves are to be expected. Because of the great depth of the sedimentary column in that area, ranging sometimes over 2000 meters, it was obvious that only the seismic reflection method could give reliable information regarding the structural features of these strata at such a depth. During the experimental surveys it appeared that the complicated geological conditions of that area do not always allow prediction of the depth and the angle of dipping of reflecting horizons, and for that reason information about the inclination of a given horizon has great importance in the determination of subsurface structure. Therefore the problem arises of obtaining from seismic reflection data reliable information as to the direction of dipping of reflecting strata, without any previous knowledge of the average velocity and depth of geologic horizons under consideration. Reflection Seismograms The earth, being a nonhomogeneous medium, is composed of a series of layers, which differ from each other in their physical properties, particularly in their elastic coefficients. These variations in elasticity are the cause of refraction and reflection of a seismic wave. Under the simple but only approximately correct assumption of the straight-line path or an elementary elastic disturbance, the phenomena mentioned

Jan 1, 1940

By Zdzislaw Specht

This paper discusses elementary laws pertaining to seismic reflection methods and presents a general and simple criterion for determining the direction of dipping of a reflection horizon from observational data of distance and time. The important development of practical geophysics and the successful results obtained in America, Germany, and other countries, caused introduction of geophysical methods of prospecting in Poland. Of all methods, seismic prospecting has proved most successful in the area of the Carpathian foreland, where new oil reserves are to be expected. Because of the great depth of the sedimentary column in that area, ranging sometimes over 2000 meters, it was obvious that only the seismic reflection method could give reliable information regarding the structural features of these strata at such a depth. During the experimental surveys it appeared that the complicated geological conditions of that area do not always allow prediction of the depth and the angle of dipping of reflecting horizons, and for that reason information about the inclination of a given horizon has great importance in the determination of subsurface structure. Therefore the problem arises of obtaining from seismic reflection data reliable information as to the direction of dipping of reflecting strata, without any previous knowledge of the average velocity and depth of geologic horizons under consideration. Reflection Seismograms The earth, being a nonhomogeneous medium, is composed of a series of layers, which differ from each other in their physical properties, particularly in their elastic coefficients. These variations in elasticity are the cause of refraction and reflection of a seismic wave. Under the simple but only approximately correct assumption of the straight-line path or an elementary elastic disturbance, the phenomena mentioned

Jan 1, 1940

By T. A. Rickard

Technology has no recognized rank in what is called polite literature; the subject-matter of engineering is not supposed to lend itself to artistic treatment; we are the hewers of wood and drawers of water to the high-priests of learning that live on the cold summit above our humbler dwellings. Therefore the hierophants smile at the notion of 'style1-" that curiously personal thingy-in technical writing. The "great art" of Pater, the "inevitable phrase" of Raleigh, the "note of distinction" that Arnold demanded are said to be beyond the scope, as they are supposed to be beside the need, of a writer on geology or engineering. This is a narrow view. Science, no less than belles lettres, calls for the best exercise of the human intelligence; the art of writing should be employed as skilfully and as earnestly in a description of the structure of the Sierra Nevada, or of the construction of a tunnel through the range, as in a rhapsody welcoming the rosy fingers of the dawn. The idea still lingers that fine writing does not befit technology, even though the masters of the Victorian period-Huxley, Tyndall, Ruskin-proved that science is worthy to be arrayed in the best robes that the looms of thought can weave. At the beginning of these lectures I quoted Barrie's remark touching the inability of the scientific man to express himself. That imputation has been passed to the technologist, whose utilitarian pursuits are supposed to make him too clumsy for the refinements of human speech. We may not have acquired the self-consciousness of those writers on Art whose "power of expression is so cultivated that their sensual caterwauling may be almost mistaken for the music of the spheres"; nor can we imitate the politicians, who have the ability to speak far beyond anything that they may have to say; but we too have a litera-

Jan 1, 1931

By Waldermar Lindgren

[The observations here presented were made during a short visit at Calico, in December, 1886. The accompanying map, which does not claim to be more than a careful sketch, is based on the position of a few mines obtained from Mr. F. Lewis, at Calico, and the plats in the Land Office with the patented claims. Only a few claims are shown by their boundary lines: as usual in mining districts, there is an enormous number of them, often conflicting or overlapping, the correct mapping of which would be useless for the present purpose. The rest of the topography and the drainage are mapped from sketches, aided by compass and aneroid. The elevations are taken from Daggett as base, the altitude of this station being determined by the railroad to be 2000 feet.] Until a few years ago the product of silver in California was of little importance, compared with that of gold, and often fell short of $1,000,000, the only noteworthy counties being Mono, Inyo and San Bernardino. About 1881, however, important discoveries were made in the deserts of San Bernardino, and the remarkable increase in the production may be seen from the following figures, taken from the Reports of the Director of the Mint: Silver Production of California. Of San Bernardino Co. 1883,. .. $1,460,000 $1,050,050 1884,. .. 3,000,000 2,550,000 1885,. .. 2,568,036 2,363,436 By far the largest portion of the product of San Bernardino is derived from the district surrounding Calico, although the success there has also given fresh stimulus to prospecting and mining in other parts of the county. San Bernardino borders towards the east on Nevada and Arizona, towards the south on San Diego County, California. Topographically, as well as geologically, the largest part of it belongs to the Great Basin. Broad shallow lake-beds or valleys with an elevation of 2000 to 3000 feet, are separated by low mountain chains and

Jan 1, 1887

By Harold Earle Cook

The purpose of this paper is to state briefly the inspection requirements of the Bureau of Ordnance, the specifications governing the inspection, and the physical and chemical properties of the steel used in the construction of ordnance for our Navy. It would be of interest to evoke discussion on points in these specifications which do not tend to insure the production of the very best material for the purpose intended. In other words, what requirements of our specifications are useless and also in what manner are our specifications deficient? It might be well at the start to answer the first criticism of this paper which will probably be made, and that is that the title does not agree with the subject matter. Considering metallographic work as covering only the macroscopic and microscopic examination of metals, this paper will have gone beyond the subject; but it is believed that a broader definition of metallography is that it is the study of the relation of the internal structure of metals and alloys to their composition and to their physical and other properties. The internal structure of steel is dependent on its physical and its chemical properties. These physical properties are dependent on the chemical composition and the mechanical and thermal treatment of the steel. So it seems that this subtitle would not be entirely necessary and that the title " Metallography of Steel for Ordnance Purposes" would cover a study, not only of what we can learn of macroscopic and microscopic examination, but broadly of the whole subject of the specifications, the fulfillment of the requirements of which produce the structural conditions revealed by macroscopic and microscopic examination. I will refer but briefly at the beginning to the microscope and its uses in our inspection. It is only very recently that the Bureau of Ordnancc has furnished certain of its inspection offices with a portable Tassin outfit for the microscopic examination of steel. Since that

Jan 1, 1916