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By Alden B. Greninger

THE study of mosaic structure of crystals1 has been confined until recently to the field of theoretical physics Crystallographers, in general, have neglected the subject, although X-ray crystallographers constantly make use of formulas for intensities of X-ray reflection as modified by mosaic structure Work on mosaic structure has centered chiefly on the task of proving or disproving the secondary-structure theory of Zwicky,2 and very little attention has been paid to the visible imperfections of crystals A Goetz has been responsible for most of the supposed experimental confirmations of Zwicky's theory 3 On the other hand, Smekal,4 and Orowan,5 among others, maintain that these is neither theoretical nor experimental evidence to substantiate Zwicky's secondary structure

Jan 1, 1935

By W. Rostoker

A STUDY of the titanium-oxygen system' involved an associated series of measurements of the lattice parameters of the a and TiO phases. The results permit some interesting deductions which are herein reported. A comprehensive survey of the physical PI-operties of the phases in this alloy system has been made by Ehrlich.2 However, only impure titanium was available at that time, so that some revision of his measurements is to be expected. The lattice parameters were calculated from the high angle lines of Debye-Scherrer patterns taken in a 14 cm camera and using filtered CuKa radiation. The specimens were prepared largely by crushing and screening of lump samples which had been quenched from elevated temperatures. Only in the case of low oxygen contents was it necessary to resort to filing and annealing. The results of the lattice parameter studies are graphically presented in Figs. 1 and 2. It will be seen that oxygen produces a pronounced distortion of the c parameter of the a phase (hexagonal close-packed). The trend is in general agreement with Ehrlich's work, although the divergence of actual parameter values strongly suggests that his titanium was very impure. It will be noted that the a phase of titanium can tolerate the unusually high saturation solubility of about 34 atomic pct 0. By virtue of this unique effect, it is possible to make a calculation of the effective atomic diameter of oxygen when dissolved in a lattice with metallic bonding. This has not been possible before. Ehrlich's2 density measurements demonstrated that oxygen occupies interstitial positions in the a lattice and the trend of the lattice parameters would certainly support this. In a hexagonal close-packed unit cell the largest interstitial positions lie at (2/3, 1/3, 1/4) and (2/3, 1/3, 3/4). Accordingly, if both of these positions were occupied, the ratio of titanium to oxygen would be 1:1. The extrapolated c parameter may be taken as between 4.93 and 4.99?. The a parameter appears to reach a constant value of 2.955? at low oxygen contents. The distance of the center of a titanium atom site from the [vc2/16+a2/3-1.448] Then the atomic diameter of the oxygen atom is represented by the function: where the radius of the titanium atom is 1.448A,

Jan 1, 1953

By B. G. Bunting, J. H. Johnson, H. J. Schock

This paper describes an experimental method for monitoring diesel-generated exhaust gas pollutants in a deadended drift to assess the effect of control approaches. Experiments were conducted to determine the relative merits of these ventilation configurations: no auxiliary ventilation, induction ventilation at the entrance to the drift, and ventilation of the dead-ended drift with positive displacement tubing. The drift used in this experimental work was approximately 32 m long and slightly downsloping, with an everage height and width of 2.4 and 8.6 m, respectively. For this drift, it was found that ventilation with positive displacement tubing provided the best removal of diesel-generate pollutants. Induction ventilation appeared to be the least effective of the three methods examined.

Jan 1, 1982

By J. W. Rutter, K. T. Aust

The migration of individual, large-angle grain boundaries has been studied as a function of tempereature and solute concentration in specimens of zone i.e filled lead containig very small additions of silver and of gold. Tile results are compared with various the-ories of grain boundary migration and with observations made prev.iorlsly of grain boundary migration in similar specimens of zone-refined lead containing tin additions. A previous investigation by the authors dealt with [he temperature dependence of grain boundary migration in bicrystals of zone-refined lead containing small additions of tin.' It was shown that tin additions as low as a few parts per million cause a large decrease in the grain boundary migration rate at any given temperature, as well as a marked increase in the temperature dependence of the migration rate. It was found that existing theories of grain boundary migration. based on the motion of dislocations. or upon the concept of atom transfer in groups across the boundary (group process theory). or upon the control of grain boundary motion by volume diffusion of impurity atonls along with the boundary. are incapable of accounting for the observations. The single process theory of grain boundary migration. which is an absolute reaction rate calculation based on the transfer ui atoms singly across the moving boundary, was found to predict the migration rate reasonably well for a number of boundaries whose motion was shown to be very little influenced by impurities, but not for boundaries whose illation was influenced markedly by impurities. It was concluded that the elementary process of grain boundary migration involves the activation of single atoms during transfer across the boundary. and that inadequate knowledge is available to permit the influence of impurities to be properly taken into account. The present study was initiated to check the validity of the above conclusions with other alloy systems, namely high-purity lead with small additions of silver and of gold. Both silver and gold diffuse faster. and with a lower activation energy of volume diffusion. than does tin in lead;' consequently, a study of the effects of silver and gold on grain boundary migration in high-purity lead offered a means of testing theories of boundary migration based on bulk diffusion of the solute (eg. ref. 3). In addition. it was hoped that the present work, in comparison with the results for tin in lead, would provide information concerning which factors are important in determin- ing the interaction between solute atoms and a grain boundary. EXPERIMENTAL PROCEDURE The preparation of bicrystals of zone-refined lead, with various silver or gold additions, was identical to that previously described for the lead-tin alloys.''4 Each bicrystal consisted of a striated crystal which was grown from the melt. and an adjacent striation-free crystal which was introduced by artificial nucleation and growth.''4 The striation or lineage substructure in the melt-grown crystal provided the driving force for grain boundary migration. During the preparation of striated single crystals by growth from the melt, it was found that silver or gold concentrations as low as 2 or 3 ppm by atoms were sufficient to cause formation of the hexagonal cell structure. which is due to the presence of impurity, during freezing. This structure is revealed on the solid-liquid interface by decanting the liquid during freezing. The hexagonal cell structure was observed previously4 in zone-refined lead crystals with tin contents above approximately 200 ppm by atoms. These concentrations of silver, gold, or tin are in agreement with the predicted amounts required for cell formation in lead,5'6 under the present conditions of freezing.4 The absence of cell structure at decanted interfaces, therefore, served as a useful indication that the silver or gold contents were less than 2 or 3 ppm by atoms in the specimens as grown. It was found that grain boundary migration occurred only very slowly when the solute content approached that necessary for cell formation. As a result, the present experiments were conducted with silver or gold additions less than 1 ppm by atoms. This impurity level is well within the solid solubility limits for silver and gold in lead.7 The annealing treatments, measurements of grain boundary velocities, and orientation determinations were carried out as described previously.' However. each bicrystal was also chemically polished in a solution consisting of 8 parts glacial acetic acid and 2

Jan 1, 1961

PLANS for development of the San Manuel ore- body have been worked out and are progressing parallel with construction of the surface plant. This property lies in the Old Hat mining district, Pinal County, Ariz., about a mile south of Tiger where the St. Anthony mine once produced gold, molybdenum, vanadidn, lead, and zinc. Two development shafts have been completed and serve as ingress for preparation of the 1475 haulage level and 1415 grizzly level. Three other shafts are being put down. The Nos. 3A and 3B shafts will provide the ore hoisting facilities. The No. 4 shaft, now being sunk, will be at the main mine service and supply yard, with primary function to provide the mine with supplies.

Jan 7, 1954

THE following employment items are made available to AIME members on a nonprofit basis by the Engineering Societies Personnel Service, Inc., operating in cooperation with the Four Founder Societies. Local offices of the Personnel Service are at 8 W. 40th St., New York 18; 100 Farnsworth Ave., Detroit; 57 Post St., Son Francisco; 84 E. Randolph St., Chicago 1. Applicants should address all mail to the proper key numbers in care of the New York office and include 6c in stamps for forwarding and returning application. The applicant agrees, if placed in a position by means of the Service, to pay the placement fee listed by the Service. AIME members may secure a weekly bulletin of positions available for $3.50 a quarter, $12 a year. MEN AVAILABLE Geologist-Petrographer. Experienced subsurface geology and petrographic rock and mineral identification. Desires position as either geologist or petrographer. M-682. Geologist, 36, married, employed. Nine years' experience geology connected with engineering, includes planning and supervising core drilling programs, study of stratigraphy and structure, special problems, report writing. Three years' teaching experience. Desires responsible position offering opportunity for advancement with progressive concern. Will travel part time. Available reasonable notice. M-683. Mining Executive with record of accomplishment organizing and directing efficient low cost mining and ore dressing operations available for position in the United States. Broad experience engineering, mechanized mining, flotation, safety, union labor relations and preparation of reports. Married. Employed; available upon reasonable notice. M-684.

Jan 1, 1952

By R. D. Pehlke, J. V. Gluck, R. L. Louvet

A study has been made of the effect of small additions of bismuth on the activity of zinc in dilute solution in molten tin. Free-energy interactions have previously been determined between zinc and various third elements where the solvents were molten bismuth or molten lead.'-4 In both of these solvents, the activity of zinc exhibits a strong positive deviation from ideal behavior (at 550°C y° for zinc in lead is 11.4 and for zinc in bismuth is 3.0). The present work, using tin as the solvent, is an extension to a case where the positive deviation is considerably diminished (y°Zn at 550°C is 1.63). Several previous investigators have studied the Zn-Sn binary system; however, little data is available in the range below 0.1 mole fraction zinc.5= Previous high-temperature galvanic cell studies in the Sn-Zn-Bi ternary system included the determination by Gluck and Pehlke of interactions in the bismuth-rich corner1 and separate investigations of the central region by Oleari and Fioriani6 and by Ptak and Moser.7 Yokokowa et al.8 conducted Knudsen effusion studies in the central region; however, their experiments at 625°K were conducted somewhat below the present experimental temperature range. Their results indicated an increase in zinc activity with the addition of bismuth. The present series of experiments was conducted in galvanic cells represented as follows: Zn Zn++ in LiCI-KC1 eutectic Zn + Bi in Sn (pure reference (fused salt electrolyte) (molten alloy) standard) The experimental apparatus. a multi-electrode system employing alumina crucibles and contained in a Vycor tube under a helium atmosphere, has been described previously, as have been the experimental procedures, precautions, and the methods of data reduction.1-4,- The experimental measurements were made over the range from 450° to 650°C. Between thirty and forty measurements were made in each run. The linearity of the electromotive force vs temperature relations was verified by linear regression techniques. The correlation coefficients exceeded 0.99. The experimental results summarized in Table I include the interpolated electromotive force at 550°C and the temperature dependence of electromotive force. Only results from stable and consistent cells containing more than 0.025 mole fraction zinc are reported. Attempts to run cells at 0.01 or 0.02 mole fraction zinc were not satisfactory. This is attributed to the closeness of the free energies of formation of the chlorides of tin and zinc. Calculations employing Wagner and Werner's criteria for displacement reactions10 indicated that reduction of the zinc content to 0.01 mole fraction places the cell near the borderline concentration for a 1 pct error in measured potential. The compositions shown in Table I are the actual weighed-in amounts. Previous experience has indicated that compositional changes during the running of a stable cell are negligible.' Over the range of compositions studied for the binary alloys, the activity coefficient of zinc was essentially constant indicating that Henry's law is followed to 0.05 mole fraction zinc. The temperature, OK, de-

Jan 1, 1969

By John B. Knaebel

The annual Jackling Award Lecture, sponsored by the Society of Mining Engineers of AIME, is intended to honor and commemorate one of the greatest mine-makers of all time, an innovator whose vision and determination made ore out of waste rock. He ushered in a new philosophy of mining which revolutionized some segments of the industry and notably affected our economy generally. To have been asked to given the Jackling Lecture this year is an honor that I scarcely deserve, but which I have accepted in humble gratitude. Although it is true that "many a mine has made the man," it is also true that while ore bodies are found, mines are made. That statement has been hammered into my skull many times by a man whose own career exemplifies its truth, a man who has been first and last a steadfast friend, who for a while was my boss and mentor, and who as one of this country's great mining geologists has laid his hand to the making of many a mine. I will doubly cherish the memory of the honor bestowed upon me because the presentation of the Jackling Award was made by this man. After the Lord made Dick Hunt he threw away the mold. Metals and other mineral products are essential ingredients of the social economy of the modern world. No well informed and thoughtful person can doubt that they will be indispensable to mankind as long as the fabric of civilization as we know it today can be held together. They are mined from ore bodies, which, unlike some other kinds of bodies, are physically inorganic and wholly incapable of reproducing themselves. Since in time they become mined out, an endless procession of new producers must be made by someone if the fundamental needs, to say nothing of the not so fundamental whims of an affluent society, are to be gratified. In saying that these mines must be made, I mean exactly that. It is my purpose to comment upon some of the problems we must cope with in making them. I shall try to avoid dwelling needlessly upon aspects of new mine development with which most people in this business are thoroughly familiar, and will attempt to discuss in a useful way some of the newer and more significant features of the economic climate in which these endeavors must be conducted. To begin with, an Almighty force put the ore into the ground, and selected the places in which to put it. Mankind was not consulted. Beyond that stage, however, mankind must find the ore deposits and contrive to extract their contents and put them into useful service. In doing this, he must use tools and techniques devised by man to overcome obstacles created in part by nature, but also in part by man himself. And most importantly of all, in making the tools and applying the techniques, he must use people. In the whole process the most pliable ingredient at hand-and also the most unpredictable-is people. Mines play out, and men die. As time goes on, we will have new mines, and they must be made by new men. The Environmental Dilemma It is perhaps timely to touch first upon the newest and in many ways the most potent consideration affecting the feasibility of developing new mines-the problems related to protection of the environment and to the

Jan 1, 1973

By E. P. Pfleide, L. W. Gibbs. J. R. Gross

A method using computer techniques is described for the comparative evaluation of truck performance over any given haul road using readily obtainable manufacturers' data. An additional computer program is utilized to calculate individual cycle times for each truck and shovel combination, fleet requirements for any desired production rate, and to estimate comparative costs. The introduction of a large number of variables into the program permits management to determine the critical system factors having the greatest bearing on costs. Thus, the method described can be used not only for analysis of needs for a new surface mine but for cost improvement in existing mines where changes in truck and shovel operations are contemplated. The systems analysis approach to the solution of problems in the mining industry is gaining in industry acceptance. This is a logical development in view of the fact that a mine constitutes one of the most dynamic systems of production. In contrast with a manufacturing plant, situated in a location selected through choice and utilizing a regulated source of quality controlled raw materials, the miner must go where the ore is and he is faced with ever changing physical conditions. He is subjected to the vagaries of nature, and he can never mine the same ore twice. What is systems engineering? There seems to be no concise and universally accepted definition of the term and its meaning is still fairly local. It deals largely with trade-offs of subsystem characteristics to achieve some desired result in an overall system. This concept of suboptimization can be explained by an example. If the objective of a mining company is to produce a certain quality ore at minimum cost, the optimum operation is not achieved by minimizing all costs, since all phases of mining are interrelated. Reduction of blasting costs might well increase loading, hauling, and crushing costs out of proportion to the resulting saving in explosives. Hence tradeoffs are necessary. It is evident then that an optimum system is achieved through a blending of suboptimal components which taken together yield the desired result. OBJECTIVE For our mathematical model we will assume the existence of a hypothetical new organization called Taconite Mining Co. (TMC). TMC has made an analysis of their orebody, their proposed operation, and

Jan 1, 1968

By J. G. Davis, P. C. Thakur

Hazardous methane gas in coal mining is receiving increased attention due to the increased US demand for coal which has resulted in the exploitation of deeper seams and the utilization of more productive equipment. Problems posed by methane emission has the Mining Research Division of Continental Oil Co. (Conoco) accelerating efforts that began in the early 1950's with Consolidation Coal Co. (Consol).1 The program's focus is on finding new techniques for degasification of virgin areas as well as control of methane in gob areas.

Jan 10, 1977

By T. B. Brooks

THE iron ores of the Marquette region are mostly extracted in open excavations ; hence the process is more properly quarrying. Several attempts at underground work have been made, which have not, on the whole, been successful. The Edwards mine has been almost entirely wrought by candle-light. The slate ore pit, No. 1, of the New England mine, is now worked in the same way, as is also the Pioneer furnace pit of the Jackson mine. The Champion mine was opened systematically for underground work, with two levels, 60 feet apart, and three shafts at distances apart along the bed. of 200 feet; but this idea has been practically abandoned, the greater part of the ore in that mine being now taken out in open pits. Several other mines have occasionally worked underground stopes, but only temporarily; if such stopes could not be opened out to day-light, they have usually been abandoned. In brief, it may be said that no considerable amount of ore has as yet (1870).been extracted underground in the region, and of that so mined very little has been taken out at a profit; and I may add that it seems to be the belief of the most experienced mining men that this state of things will hold for some time to come for reasons which will appear. Nearly the same remarks may be applied to the mines of the Iron Mountain region, Missouri, the ores of which are very similar in character to those of Marquette. Some of the New York and New Jersey magnetic deposits are wrought open, but this is the exception, underground mining there being the rule. The following brief sketch of the geological structure of the Marquette deposits will indicate some advantages of the method of mining employed. The iron-bearing (Huronian) series of rocks, are stratified beds, the principal ore formation being overlaid by a quartzite, and underlaid by a diorite, or greenstone. This ore formation is made up, first, of pure ore ; second, of a mixed ore" (i. e., banded * A second part of this paper was read before the American Society of Civil Engineers. Both papers are embraced in Chapter IX, Part I, Vol. II, Geological Survey of Michigan.

Jan 1, 1873

[†ADAIR, ARTHUR C., Corp 4th Co., 1st. Training Bat., 154th Depot Brigade. ADAMS, HENRY, Major Chemical Warfare Service. ARLUCK, A. A Headquarters, 1St Corps of Artillery. ASKIN, THOMAS B. H Ensign.] [ ]

Jan 1, 1925

By Lester F. Engle

Books have been written, complex charts drawn, great batches of punched cards handled by ever increasing numbers of computers, and innumerable meetings held-all for the purpose of making effective the ultimate objective of new, revised or improved process facilities. It is to the credit of management, engineers, and others that in the vast majority of cases, the outcome of their work has been technically sound and economically rewarding. There is a way, however, to insure even better results.

Jan 5, 1966

[James C. Gray, President W. B. Stephenson, President-Elect A. B. Cummins, Past-President E. G. Fox, Eastern Regional Vice-President H. C. Weed, Western Regional Vice-President Donald W. Scott, Central Regional Vice-President John Cameron Fox, Secretary 29 W. 39 Street New York 18, N. Y. After September 7, 1961 345 East 47 Street, New York 17, N. Y. D. R. Tone, Assistant Secretary Nathaniel Arbiter, Treasurer]

Jan 1, 1961

By A. H. Hand

When considering the question of future demand for crude petroleum in California, one must first decide whether it is to be approached in the light of the definition of "demand" when used in economics; i.e., "The quantity of any commodity required or sought in the market," or in the light of markets developed to dispose of total supply. Therefore, is the California demand of future years to be predicated on a continuation of supplying markets developed following the surplus production commencing in 1922, or predicated on supplying what would be termed economic markets ? If the latter, what are economic markets ? Obviously, the Pacific Coast States and Canada, Alaska, Hawaii and probably the Pacific side of Central and South America, can be considered as normal markets for California petroleum products. While there have been small quantities of gasoline shipped into the PacSc Coast from East Texas, transportation costs, plus import taxes in the case of foreign oil, are a sufficient barrier to justify considering that these markets will be retained. But how about our participation in Atlantic and Pacific foreign and intercoastal markets? During the five years preceding 1931 California shipped substantial quantities of gasoline to the United Kingdom and to France, Germany and Italy. During recent years our business in European markets has been restricted to occasional shipments of gasoline and Kettleman crude. This loss of business is occasioned by the development of production in the Mid-Continent, principally East Texas, and in Iraq, Rumania, Venezuela and other closer producing areas, which makes it impossible at the prevailing crude-oil prices for California to be competitive in supplying any substantial portion of these markets. It is therefore apparent that under a stabilized price structure that will return the California producer a reasonable price for his oil, future Atlantic foreign -business will be restricted to occasional spot cargo sales. As to Pacific foreign shipments which, in addition to Central and South America, consist principally of shipments to Japan, China, Australia and New Zealand: A considerable portion of the business we had with Australia and New Zealand until four or five years ago is now being

Jan 1, 1937

IN comparing the living conditions of the worker or peasant of the past with those existing today, his-torians might point out many strange contrasts. From the Doomsday Book we learn that at the time of Wil-liam the Conqueror the 1,375,000 inhabitants of Eng-land and Wales owned less than 1000 horses and 5000 oxen. Even as recently as 1871 when England and Wales had a population of 31,845.000, the total number of horses in the country was estimated at 1,110,000. Compare the necessary drudgery of labor in those days with conditions in Canada today where a population of less than ten million people own 3,500,000 horses. Re-member that there is also a turbine installation in` this country of more than four million horse-power, besides steam boilers and locomotive and automobile engines which reduce the traction and hand labor of the farm and factory. Frequently, poetic license has glossed over the poverty and hardship of the common people in the "good old days," and the imagination has created an idyllic world, far from being justified by the condi-tions which actually prevailed. Simon Patten's de-scription of the Middle Ages as "A Thousand Years Without an Ice Box" came nearer portraying the true situation. No one is likely to forget that the discovery of America was an incident in Europe's attempt to find a short route to the Indies, but the fact is usually for-gotten that the summer diet in Europe in 1400-an ice-less age-was such that spices were more precious than gold. Though the glamor of the Indies may never sur-round the modern refrigerator, certainly the modern housewife is likely 'to feel that the applied art called "cookery? may attain to higher levels with the assist-ance-6f such an adjunct. Those who have spoken slightingly of the uniformity of the modern apartment and have eulogized some of the exceptional hand-made furniture which has been bequeathed by former generations, have failed to com-pare modern house furnishings with those in the typical peasant's hovel. Machine-made furniture, though with-out particularly good lines, contrasts quite favorably with the pile of rags in the corner, and the poorest gas or oil stove is better than an open fire on a dirt floor. The scientist's application of the theories of physics, chemistry, biology and mathematics .to practical prob-lems has brought about a series of kaleidoscopic trans-formations in agriculture, industry and commerce. Large scale production, improved means of communica-tion and the prevailing higher standard of living are terms which imply a very human meaning when in-terpreted as actual changes in individual living. Though the student and the teacher may deprecate the influence of commercialism upon science, humanity as a whole has received great benefits from the close relationship which has developed between science and industry, and industry in turn has done much for science through the building and endowment of laboratories and by supply-ing funds to maintain research workers.

Jan 11, 1927

By B. R. Palmer, M. C. Fuerstenau

Oxide and silicates respond to flotation with a large number of anionic collectors. These include carboxylates (fatty acids), sulfonates, alkyl sulfates, and certain chelating agents. In contrast to sulfide mineral flotation, relatively long-chained collectors (generally longer than 10 carbons) are required to effect flotation of this group of minerals. The structural formulas of these various anionic collectors are presented in Table 1. Formulas and solubilities of various fatty acids are presented in Table 2. These solubilities are those of the dissolved and undissociated species of the acid, e.g. oleic acid, HOl(aq). Of the compounds listed, oleic acid and abietic acid, which IS a major constituent of talloel, are used most commonly in commercial applications. The usage of these two collectors is related to cost and effectiveness. In addition to their high molecular weights, oleic acid contains a double bond in its hydrocarbon chain, while abietic acid is comprised of aromatic rings containing double bonds. The presence of double bonds increases solubility significantly over that of saturated homologues. Stability of metal-collectors assumes a most significant role in these systems, and the solubility products of various metal carboxylates and sulfonates are listed in Tables 3, 4 and 5. In addition to these properties, strength of the acids of these various anionic collectors is also important. The carboxylic and hydroxamic acids are weak acids whereas sulfonic and alkyl sulfuric acids are strong acids. All of the carboxylic acids fall in the range of pK = 4.7 ± 0.5 ([2]); the pK of hydroxamic acid is around 9 ([3]); and the pK of sulfonic acid is about 1.5 ([4]).

Jan 1, 1976

By R. T. DeHoff

A new approach to the measurement of the size distribution of particulate structures imbedded in opaque bodies is developed. The method is based upon the assumption of a general two-parameter distribution curve, and the estimation of these two parameters from three well-known counting measurements made upon metallogvaphic sections. The total number of particles in the system is also a product of the analysis. Application of the method with the assumption of the logarithmiconorma1 disfribution function is developed in detail. A complete description of the geometry of a particulate structure requires the determination of the size distribution of particles. The problem of estimating the size distribution of particles of a particular phase in a multiphase system, or the grain-size distribution in a homogeneous system, has been approached by many investigators.'-'0 All of the solutions proposed by these investigators share the following characteristics. a) A minimum of several hundred particle sections in the microstructure must be examined, and some characteristic dimension recorded, such as area,3'5 intercept length,6"9 or diameter.1'2'4'10 b) The resulting data must undergo a series of fairly complex calculations to generate the empirical histogram which describes the size distribution in three dimensions. c) In order to manipulate the result, the histogram must be fitted to some assumed mathematical formula, using the attendant statistical procedures. d) With two notable exceptions,8,10 the particles must be spherical. The measurements and calculations involved are in general very tedious and time-consuming, with the logical result that much effort has been expended in the development of equipment which will perform these tasks automatically and semiautomati-cally.9,11-15 considerable success has been achieved in this area, but the equipment is in general expensive, and usually places stringent requirements On the quality of microstructure which can be reliably analyzed. In laboratories which do not possess such equip- ment, the analysis of geometry is usually limited to measuring total properties of the microstructures, such as volume fraction and interfacial area, because the measurements required are much simpler to make. The determination of size distributions rarely is undertaken. The development which is presented in this paper permits the estimation of size distributions of three-dimensional structures from the same simple counting measurements which are required to determine the surface area and volume fraction of the particulate structure, and one other counting measurement. The basic approach that is used is to assume a general mathematical form for the distribution, which is described by two parameters (as the normal distribution is described by assigning values to the mean and the standard deviation), and then estimate these two parameters from the results of the counting measurements. The introduction of a third counting measurement also permits the evaluation of the number of particles per unit volume, Nv.

Jan 1, 1965

By Walter C. Smith

THE Cerro de Pasco Copper Corp. began to produce bismuth at the Oroya smelter in 1929, at which time the only important consumption of that metal was in the manufacture, of pharmaceutical compounds, and the normal supply of metal exceeded the demand. With a new and major producer entering the field, additional uses for bismuth had to be developed. A survey indicated that the most promising opportunity lay in fusible alloys containing bismuth. A large number of bismuth alloys were known and a few of them were being used in the manufacture of automatic sprinkler heads and safety plugs. The literature cover in,- the- alloys was found to be sketchy and contradictory. Research, development, and educational work carrried on by the Corporation during the past fifteen years has resulted in greatly enlarged uses for the metal. In general the low-melting bismuth alloys are of high specific gravity, relatively soft, of low tensile strength, brittle to shock, yet subject to plastic

Jan 1, 1945

By W. F. Cloud

The data and information compiled under Part I of this report are the results of experiments performed in the petroleum engineering laboratory under the supervision of W. F. Cloud, Associate Professor of Petroleum Engineering and William Schriever, Professor of Physics, University of Oklahoma. Problems Being Studied Most of the time has been spent in trying to determine the rate of flow and pressure gradient in a 4-in. flow tube 10 ft. long, which was packed with sand of various grain sizes. To date, only two kinds of sand have been packed in this tube: 60 to 80-mesh Canadian river sand, 60 to 80-mesh and 80 to 100-mesh Simpson sand. The original intention was to follow the same procedure and use the same types of crude under identical saturation pressures of both air and gas, as well as unsaturated (dead) oil, flowing the various crudes through several different sizes of both Canadian river and Simpson (Wilcox) sands, but lack of time has prevented such an intensive study of the problem. Some additional time has been spent flowing saturated and unsaturated crudes, similar to those used in the 4-in. tube, through 1-in. tubes, one of which was 2 ft. long and one 5 ft. long. The results obtained have been checked against those obtained by using the 4-in. tube, to obtain the relation of diameter and length of tube to rate of flow in similar sands. Laboratory Equipment Saturation Tank.—A heavy steel cylindrical saturation tank, capacity about 42 gal. was mounted on a platform of bricks, then a galvanized tin temperature bath was built around the saturation tank. This contained

Jan 1, 1930