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By J. J. Kramer, W. A. Tiller, G. F. Bolling

The temperatures of solid-liquid interfaces have been measured during the growth of Sn-Pb alloy crystals which exhibited a cellulur substructure. A simple descriptive theory was used in combination with this data and the other measurable growth variables to predict some features of the solute segregation such as the intercell excess concentration and the depth of cell grooves during freezing. The effective distribution coefficient at the tip of a cell, a, was predicted and experimentally found to vary in the range, 1 >a > k0. At the lower limit, the severe segregation that must arise between dendritic cells was substantiated by various observations such as the existence of a second Phase even for alloys of only 0.2 wt pct Pb. ThE cellular morphology of a solid-liquid interface is known to coincide with the formation of a zone of constitutional supercooling ahead of the interface during growth.' The occurrence of various cell structures, (two-dimensional cells, regular cells, dendritic cells), has been quantitatively investigated,'2,4 but the segregation of solute which arises as a consequence of this mode of growth has only been examined qualitatively. An indirect method of obtaining the solute concentration at the tip of a cell cap during solidification has been de-

Jan 1, 1963

By Berlen Moneymaker

THE development, within recent years, of core drills capable of drilling holes up to 72 in., or even more, in diameter, has made possible an entirely new and valuable method of geologic exploration, Although little used until recently as an exploratory tool except in the United States, by the Tennessee Valley Authority and the Corps of Engineers of the U. S. Army, for the exploration of damsites, the large-diameter core drill may be used to good advantage in other types of geologic exploration. Its princi-pal utility is that of supplementing, rather than replacing, other means of exploration. Although core is frequently recovered intact, the greatest advantage of large-diameter drilling is that the holes produced are large enough to be entered by the geologist and engineer, and thus afford an excellent means of examining undisturbed rock. The walls of the holes are smoothly cut, and in some rocks nearly or quite polished, so that the most minute details of structure and stratigraphy are clearly disclosed. Such features as faults, joints, bedding planes, weathered "seams," and beds or layers of soft materials, which are not always amenable to disclosure by cores recovered from small-diameter holes, are conspicuously displayed in the walls of large holes. Frequent reference to the drilling of large-diameter holes is made in engineering literature, but comparatively little emphasis has been placed on their value in geologic investigation. It is, therefore, intended that the present paper acquaint the geologist, as well as the engineer, with the large-diameter core drill and the technique involved in its use, and also with its advantages, disadvantages and limitations as an implement of geologic exploration.

Jan 1, 1938

By E. P. Bucklen, L. J. Prelaz, J. R. Lucas

Today, the future of the coal industry is extremely bright because coal can be produced at a cost which makes it competitive with other energy sources. However, the industry has been forewarned that further cost reductions must be made if it expects to remain a serious contender in the growing energy market. Surface as well as underground operations must be improved. The very same elements which affected production a few years ago still exist today and will continue to be present in the future. Improvements in production mining equipment, mining methods and auxiliary equipment have resulted in reduced costs over the past few years. Efforts must be continued toward further reducing costs in areas which have been previously improved and new areas should be investigated for possible improvements. Therefore, new techniques must be developed which will enable the industry to augment its current efforts in reducing the cost of mining. The logical place to begin evaluating the factors affecting production and cost is in the immediate face area where a substantial part of the total cost of mining is incurred. The coal industry stands to gain much through the development of new techniques for analyzing the numerous variables affecting production and by establishing methods for eliminating or minimizing the adverse effect of those variables which can be controlled. Intuition and trial-and-error methods have been the standard means used to resolve many of the factors which influence production. As a result, many elements are overlooked or ignored because their effects on production are not pronounced and cannot be readily resolved.

Jan 3, 1965

By Horace Pops, Jorge E. Kittl

In a recent study' of the martensitic transformation of Cu-Zn ß-phase alloys, it was noted that the MS temperature at the surface was raised due to the loss of zinc by volatilization. It seems likely, therefore, that the MS temperature may serve as a guide for the measurement of composition. From a knowledge of the dependence of the transformation temperature on composition, 2 it should be possible to detect variations in zinc content which are less than 0.1 at. pct by measuring the MS temperature throughout the sample. It is unlikely that an electron microprobe analysis could detect accurately such small zinc losses because the presently accepted limits of accuracy of the micro-probe analysis in simple ternary systems are of the order of 2 to 5 pct of the amount present.3 In the present study, a composition gradient was produced by precipitating the a primary solid solution, and reheating for a very short time within the ß-phase field. The nominal composition, in atomic percent, of the ternary ß-phase alloy used, 64.2 Cu, 34 Zn, 1.8 Si, was selected because it had an MS temperature of +4°C, thereby simplifying the experi-

Jan 1, 1968

The work of the Committee during the year 1914 was especially directed to the securing of a larger representation in the Institute of those engaged in coal mining and coking. While these industries exceed in volume and in monetary importance all other mining industries in the United States, the membership of the Institute representing them has in recent years been relatively small. It was thought that an increase in the membership of the Institute obtained from among those engaged in these industries was desirable in order to increase interest in the work of the Institute, for this result can only be reached by securing the presentation and publication of a larger number of papers relating to these industries. It is evident that the reading of such papers will tend to increase the attendance at the local and general meetings of the Institute. Sessions of the Coal and Coke Committee were held and a number of papers relating to these subjects were presented at the meetings at Butte, Salt Lake, and Pittsburgh, the Pittsburgh meeting especially being planned with this in view. The activities of the Local Section of the Institute organized in the Pennsylvania Anthracite region have reawakened interest in that district and it is hoped that the same object can be obtained in the bituminous coal fields, either through the organization of one or more. local sections, affiliation with some of the local coal-mining societies, or through activities of the Coal and Coke Committee. Referring to the work of the Committee in its efforts to increase the membership of the Institute, the Committee desires to acknowledge the services rendered by many members scattered throughout the various coal-mining districts of the United States, in compiling lists of those qualified for membership in the Institute, but who have not yet become members. The lists so compiled comprised about 1,100 names, which were furnished to the Committee by the co-operation of 40 or 50 members of the Institute.

Jan 3, 1915

By Kenneth Cottingham

The number of completions in 1944 in Ohio was only slightly greater than completions in the preceding year, but the initial daily volumes both of oil wells and gas wells declined considerably. The dry-hole ratio was a little lower than in 1943, even though in the year under review considerable effort was made to find new production. No new areas of consequence were discovered. Thirteen new gas pools, the largest of which was 1000 acres and the average 565 acres, were opened during the year. Eleven of these pools were in the Clinton sand, one was in the Oriskany, and one was in the Berea. Approximately 15 small pools might also be rated as discoveries, but because only one or two wells have thus far been completed in each, they cannot at present be properly evaluated. The latter pools average about 120 acres each. Some extensions were made to existing gas pools. The number of oil wells drilled was only one less than in 1943, yet compared with the year 1941, when twice as many oil wells were drilled, the difference is startling. Effective Aug. I, 1944, a blanket subsidy was granted of 35¢ per barrel on all Cleveland-Chatham, Coming, and Lima grades of oil, and 75¢ per barrel on Pennsylvania grade crude. The subsidy was authorized by the Office of Price Administration, with reimbursement to purchasers of the various grades made through the Defense Supplies Corporation, a branch of Reconstruction Finance Corporation. For several years the small operator, particularly the owner of stripper wells, was in a serious position. The subsidy has been a means of real help and, in addition to aiding the operator, it has prolonged the life of many small wells that otherwise would have been abandoned, with consequent loss of daily production and unre-covered reserves. It is questionable whether the price increase is sufficient to revive production of Corning grade, which has

Jan 1, 1945

By C. M. Weld

Attention has been turned recently to the exploration and development of certain large blanket-deposits of brown iron-ore in Cuba. The most conspicuous of these to-day, and the one upon which the most light has been shed, is the Mayari deposit, situated about 15 miles south of Nipe bag. Here the Spanish-Aniericau Co. has sole control over 18,500 acres of ore-bearing lands, reported by its engineers to contain 500,000,000 tons of ore. The necessary plant and equipment, with docks and railways, is now under construction for the early marketing of this ore. A similar deposit, and undoubtedly the next to be exploited, is the ore-field at Moa bay, where from 13,000 to 15,000 acres of ore-lands, immediately adjacent to the shores of an excellent harbor, have been generously covered by numerous mining-claims, practically all controlled by four large interests;. This deposit is now estimated to contain approximately 350,000,000 tons, on the basis of dried ore ready for shipment, a figure which may be increased when the western limits of the ore-deposit have been more accurately defined. Other deposits of the same type, but smaller and less accessible, are those at Cubitas, situated from 12 to 15 miles north of Camaguey city,

Jan 1, 1910

By A. T. Miesch

The purpose of this paper is to explore relations between the distribution and composition of uranium deposits on the Colorado Plateau and mineralogic, chemical, and lithologic aspects of their host rocks. The paper also appraises the host-rock sandstones as possible sources of elements in the uranium deposits. Other possible sources of elements are not discussed. Uranium deposits on the Colorado Plateau consist largely of sandstone and small amounts of mud-stone impregnated with uranium and vanadium miner- als and a suite of minor accessory minerals containing copper, lead, zinc, silver, iron, cobalt, nickel, yttrium, molybdenum, selenium, and arsenic, in addition to other elements locally. The deposits consist of clusters of closely spaced ore bodies which commonly aggregate several thousand tons, but range in size from less than one ton to several million tons. With only rare exception, the deposits show no close relation to fractures. The ore bodies are generally tabular in layers nearly parallel to the bedding in the host rocks, or they cross bedding at large angles to form roll structures. Absence of fracture control necessitates that the ore and associated elements were transported to the deposits by way of interstitial pore spaces in the sandstones. This points to the general process of lateral secretion as a possible mechanism of ore formation, and suggests the host-rock sandstones as a possible source of the metals. Roll structures in the ore

Jan 1, 1962

By John Birkinbine

The estimated product of iron-ore in 1888 throughout the world was, in round numbers, 50,000,000 gross tons, of which the United States produced about one-fourth. Great Britain leads this country in production by about 15 per cent., but the output of the United States is practically equal to that of Spain, France, Russia, Austria and Hungary combined. We produced last year nearly twice as much iron-ore as Spain, with all her exports; and we mined 20 per cent. more than Germany and Luxemburg. In addition to the domestic iron-ores consumed in this country, 587,470 gross tons of foreign ore was imported, and the amount of mill-cinder used in blast-furnaces is estimated at 450,000 gross tons. The total quantity of iron-ore required in 1888 for blast-furnaces, rolling-mills and other purposes in the United States was approximately 12,700,000 gross tons. The purpose of this paper is to indicate the principal sources of this supply, and call attention to the extent of mining operations covering many years in certain localities, which, although some of them now produce but a small proportion' of the above total, have in the aggregate added very largely to the material

Jan 1, 1889

By C. P. Karr

FOR several years, the Bureau of Standards has been working in cooperation with an Advisory Committee on non-ferrous metals on various phases of the production and testing of zinc bronzes. The work has dealt, especially with the type of metal known as "Admiralty bronze" in England and as "Government bronze" in this country and consisting of 88 copper, 10 tin, and 2 zinc. Several reports have been made on this subject and these should be considered in connection with this paper.1 FIRST SERIES OF FIVE FOUNDRY TESTS A very brief summary of the first series of five foundry tests has been made,2 but for the sake of clearness the results are given here in different form. The five foundries cooperating in this investigation were: Ohio Brass Co., Mansfield, Ohio; Titanium Alloy Mfg. Co., Niagara Falls, N. Y.; Packard Motor Car Co., Syracuse, N. Y.; National Cash Register Co., Dayton, Ohio; Bureau of Standards, Washington, D. C. The object of the work was to determine whether uniform results could be obtained with this alloy in different foundries working under definite instructions. One of the participating foundries prepared, from virgin metal, a stock of ingots of the composition 88 copper, 10 tin, 2 zinc, and at the same time poured nine test bars from this melt of virgin metal. The results of the physical tests of these bars are shown in Table 1. Examination of this table shows that the highest and most nearly uniform results were obtained when the virgin metal was cast flat in chill molds and the lowest and most variable results were encountered when it was cast vertical in green-sand molds. In this, as in all other tables, the mean

Jan 9, 1919

By Walter S. Weeks

The process of cooling air by allowing it to expand and do work in an engine is well known, but the theory of obtaining cold air by free expansion without the aid of an engine operating with cutoff has been little discussed. Case I If compressed air is allowed to expand to the atmospheric pressure through an orifice in an air line that is supplied by a running compressor, no cooling results except the negligible one due to the JouleThompson effect, which will not be considered in this discussion. The effect of moisture will also be neglected. Symbols P1 Absolute pressure in pipe line, lb. per sq. ft. P3 Atmospheric pressure, lb. per sq. ft. V1 Volume occupied by 1 lb. air in pipe. V3 Volume occupied by 1 lb. air at P3. C, Specific heat of air at constant volume, B.t.u. per lb. per deg. F. C, Specific heat at constant pressure, B.t.u. per lb, per deg. F. T1 Absolute temperature of air in pipe, deg. F. T8 Absolute temperature of air outside after expansion and mixing and coming to rest. j Mechanical equivalent of heat (778 ft. lb.) R Gas constant for air, ft-lb. per deg. F. = 53.3. Formulas Consider 1 lb. of air moving out of a pipe. The air behind it does work on it to the extent of P1V1 ft-lb. This work is really done by the thrust of the piston of the compressor and does not come from any energy that exists in the air in the pipe. The pound of air contains

Jan 1, 1937

By R. A. Young

Zinc metal production in the operating plants in the United States during 1948 was approximately equal to that of the year 1947, although new developments during the year assure higher output in 1949, if economic conditions are favorable. In the Western plants, the man-power shortage was almost completely overcome and new capacity has been or is in the process of being added to three plants; thus by December of 1948 daily zinc metal production had risen to the highest point since May of 1944 despite strikes in one large primary smelter and in one secondary plant.

Jan 1, 1949

By REED H. HYDE

IN these days of low metal prices and difficult marketing conditions, any treatment that will improve the grade of a product is of interest, particularly when the operation involves little or no addition to the total cost and may even result in a marketable by-product. Such a' combination of circumstances exists, in some cases, in the zinc industry, where it has been found that certain impurities can be removed from .the ore during the Dwight-Lloyd sintering operation, previous to reduction to metal. Consequently it is not surprising that zinc smelters having these sintering machines are paying particular attention to this phase of the operation. Loss of zinc as fume is very low under the conditions obtaining in sintering zinc ores, but impurities such as cadmium and lead are more readily fumed off and it is on this fact that the purification is based. As a result of preferential volatilization of these impurities a sintered product' is made from which purer zinc metal or oxide can be produced, while the fume may be collected and treated to recover the impurity metals. To be effective the operation must be carefully conducted, but no special equipment other than that of a well designed Dwight. Lloyd plant is needed.

Jan 1, 1931

By Josiah Royce

To evaluate chemically the sample of rock obtained by diamond drilling, it has long been recognized that the analyses of the two components of the sample, core and sludge, must be given appropriate influence in computing the average analysis of any unit of depth. The purpose of this investigation is to set forth what means are available for apportioning the effect of core and sludge on the final analysis, what variables affect the problem, and what combination of applied mathematics will closest approximate the truth under each condition as these variables proceed within their limitations. A drill hole is bored in iron ore ex- ploration principally to test variations in rock composition with depth and is usually directed as nearly normal to the bedding of a horizon to be tested as possible. This practice has a tendency to minimize variation in composi- tion laterally which in any event is not likely to be great. It is obvious that the opportunity for change in analysis of a particular rock is not statistically as great radially in a diamond drill hole where the distance in which such a change may occur is from 0.719 in. (EX bit) to 1.469 in. (NX bit) as there would be longitudinally even in a run as short as 5 ft. Variations in composition of bedded or layered rocks are usually greater normal to the bedding than parallel thereto. Even in massive rocks, like porphyries, varia- tions are functions of distance. Hence, in either case, variations along the hole are of greater effect than across it.

Jan 1, 1949

By T. L. Joseph

A DEMAND for specialized knowledge has directed engineering curricula towards competency in some particular field or occupation. Preparation for life in a broad sense of completeness has received little consideration. Ways and means are needed for weaving some of the threads of liberal education into the fabric of engineering education. Any effort to develop a humanistic-social stem of engineering education will depend largely upon the content of the courses and the type of instruction offered. Many of the courses in college curricula are intended to lay a foundation for more advanced courses to be taken later by those. who specialize in some particular field. Students in other fields lack the background necessary to take the advanced courses and have too much detailed information, soon forgotten, forced upon them if they pursue the foundation courses. To develop a humanistic-social stem for engineering education existing catalogue courses selected should follow some general plan aimed towards broad educational objectives. Courses packed with detailed factual information are necessary for the stu-

Jan 1, 1947

By E. R. Parker, C. F. Riisness

That grain size has a great effect on the mechanical properties of metals has been recognized for a long time. Bassett and Davis1 in 1919 did excellent work in determining the effect of grain size on the hardness of brass. About the same time Jeffries2 and Sykes3 ascertained the effect of grain size on the strength and ductility of several metals at temperatures ranging from 80°K. to their melting points. When creep was recognized as an important property of metals, those engaged in the study of this property tried to determine the effect of grain size4-9 on creep rates. Unfortunately, most of the investigations were conducted on only two grain sizes, often designated simply as "fine" and "coarse." It is well known that at high temperatures coarse-grained test bars creep less than fine-grained bars. The relation between grain size and size of test bar, however, has been frequently overlooked. In his early work, Jeffries2 showed that the number of grains in the cross section has a more important influence on the properties of the material than the actual grain size. More recently Hanson and Sandfordl0 and Pell-Walpole,ll in their measurements of the creep and tensile properties of tin, tested a wide range of grain sizes and correlated the grain size with the strength. Hanson9 later established the relation between the number of grains in the cross section and the creep rate. At high temperatures, generally a coarsegrained structure is considered superior in creep to a fine-grained structure, but it is evident that for a given bar size continuously increasing the grain size will

Jan 1, 1944

By L. Messulam, A. S. Appleton

Iwo major studies of the Fe-Cr-C system are available in the literature. The earlier one of Kinzel and crafts' forms the basis for the data most commonly quoted in works of reference (e.g., Metnls HandDook) though the later work of Bungardt el a1.' is more extensive and amenable to analysis in terms of isothermal sections and so forth. However it is evident from examination of either of these studies that the delination of phase boundaries on the basis of the data obtained can only be very approximate. Indeed in several instances the data are so inconclusive that this delineation is a matter of opinion. This note is to report an analysis of experimentally determined carbon activity data in this system, which, originally intended as a means of checking the self-consistency of the data for a number of alloys, enables some conclusions to be drawn concerning the 10503C isothermal section of the iron-rich corner of the system as deducible from the data of Bungardt

Jan 1, 1967

By M. K. Barnett

Engineering research consists, broadly speaking, in the investigation of the effect of the variations in a number of factors on some property of a product or characteristic of a process. The unambiguous description of the product or process requires that the property or characteristic be expressible in quantitative terms. For the purpose of practical control, it is likewise desirable that the independently variable factors governing the product or process be quantities, although this ideal goal is not always attained. Maximum efficiency—i.e., the attain- ment of the maximum amount of reliable, useful information relating to the influence of, the factors on the property of the product or characteristic of the process, for the least expense—is an important requirement for the satisfactory operation of a research organization. Obviously, a necessary condition for the attainment of maximum efficiency is an adequate knowledge of the specialized field in which the experimental research lies. While necessary, this condition is not sufficient. Proper attention must also be given to the general principles of experimental design together with the modern methods for the analysis and evaluation of experimental data. The Present discussion is confined to a single design, the so-called "factorial" design. This design is of special interest in that it attains its goal, maximum efficiency, by directly departing from the

Jan 1, 1948

By R. Philip Hammond

MONAZITE has had a Cinderella-like history. Although nearly go per cent pure rare-earth compound (rare-earth phosphate) it was sought at first not for the rare earths but for the sake of a minor constituent-thorium. The thorium, essential for the Welsbach gaslight mantle, was present in only small quantities and the principal constituents, the rare earths, were largely discarded. Gradually, however, the rare earths have developed uses of their own and today have left the thorium far behind in value. OCCURRENCE Monazite was first produced commercially about 1886, in North Carolina, where it was collected in small sluices by farmers who found it in stream beds on their land. The deposits were later exploited on a larger scale, but were mostly abandoned in a few years, when monazite from Brazil came upon the market in far larger quantities. Domestic production ceased entirely in 1906. The Brazilian source is still active, together with Indian, Dutch East Indies, and Australian deposits. Several other localities in the United States have yielded monazite, but none of these has produced commercially as yet. Monazite occurs originally in pegmatites and gneisses, through which, unfortunately, it is scattered in highly dispersed form. All commercially useful deposits consist of transported monazite sands liberated by erosion and concentrated by the action of water, which has sluiced away lighter materials and concentrated the heavy (D = 5.0 to 5.2) grains of monazite, together with ilmenite, zircon, garnet, and other dense minerals. The Carolina deposits were in stream beds; most of the other deposits mentioned are on or near the seashore, where the action of the waves has served to concentrate the monazite. In most cases today, the sands are worked to obtain the ilmenite and zircon, as well as monazite. The minerals are separated by means of sluices, dry tables, and magnetic separators, and each is finally obtained nearly pure. No crushing or grinding is necessary. The concentrates are shipped in fiber bags. COMPOSITION OF MONAZITE As Table I illustrates, monazite is the anhydrous orthophosphate of the cerium [ ] group of rare-earth elements. A small amount of yttrium and terbium group phosphate is also present.* All the rare-

Jan 1, 1946

By Thomas W. Gibson

THE Province of Ontario in recent years has come strongly to the front as a producer of metals, especially nickel, copper, silver, and now gold. Of the last named, the output for 1922 was in the neighborhood of $20,000,000. The law governing the mining industry in a community where such develop-ments are taking place will be of interest, therefore, in other places where mining laws are up for revision The first mining of importance done in this province was for copper on the north shore of Lake Huron, where the Bruce mines were opened in 1846. These deposits of copper sulfides, notwithstanding the remoteness from markets and the cost of transportation, were vigorously worked for 12 or 15 years and also intermittently later, but the active career of the mines came to an end in 1875. From first to last, a little less than 10,000 tons of copper was produced, valued at $3,300,000. All the product was shipped to England as dressed ore, contain-ing up to 13 per cent. of the metal. In. 1866, a rich pocket of gold was found on the Richardson farm near Madoc, Hastings County, but was not followed by further discoveries of a like kind and in time the excitement it caused died away. Rich silver ore was found in 1868 on Silver Islet in Lake Superior, a speck of land not larger than a good-sized ball-room. The assemblage of minerals here was practically the same as that at Cobalt, discovered 35 years later, namely, native silver, cobalt, nickel and arsenic; in addition, there was considerable argentite, which has always been scarce at Cobalt. In all, the silver produced amounted to about $3,500,000. The belief persisted that the deposit was not mined out, and in the summer of 1922, some rich ore was extracted from the roof, perilously near the bottom of Lake Superior.

Jan 2, 1923