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By Peter J. Maxworthy

INTRODUCTION There is no hard and fast rule on whether functions within a company, diversified or otherwise, should be strongly centralized or decentralized. In all diverse organizations, there are certain basic functions which remain common (or central) to each element of the business, viz: Personnel Management Cash Management Taxation Management Legal Planning Accounting Standards It would follow that each of these common factors requires some supervision at a central level to ensure that overall group objectives are met. It is true that other functions including: Industrial Relations Marketing and Distribution Production Research and Development Purchasing Management Accounting may also be common to each element of the organization. However, there is far less commonality in the degree to which these functions are central to the efficient performance and financial well-being of the business. Role of Operating Units The resources of operating centers may be viewed as a bank of funds, the nature of which can be changed from time to time, but the employment of which must provide for ongoing increases in the net worth of the total enterprise expressed in terms of market values. Operating units are required to continually review products, methods, and opportunities and to monitor avenues for incremental investment--all with a view to attaining the necessary additive net present value of future cash flows of the enterprise. Operating units should be permitted sufficient autonomy to enable the best use to be made of the skills and experience of the people it employs in order to produce a return appropriate to the value of assets employed. Role of Head Office The head office will typically comprise a specialist group--the leaner the better if one strongly adopts the decentralist approach--often acting as Service Centers but also performing a control function in the corporate sense. The head office function is a cost center. It may be instrumental in developing strategies for increasing revenues or reducing costs on a group scale, but it does not generate revenue. Every dollar spent on this function is an extra dollar to be generated by the operating centers in order to achieve an increase in corporate wealth. TREASURY MANAGEMENT Treasury management is concerned with the provision of finance, cash-flow management, and risk analysis. Each decision taken within the enterprise has a cash implication. It follows that a well-integrated central Treasury function can, in all likelihood, produce economic benefits. The degree to which the function should be centralized depends largely upon the unique nature of the operating units it is servicing. Levels of ownership, the calibre of unit operating managers, and the nature and geographic distribution of the business are all factors determining the degree to which the Treasury function is centralized. In the case of Peko-Wallsend, the Treasury Department is small, comprising four people. While divisional cash-flow management is largely decentralized, Treasury is responsible for the daily management of funds surplus to the immediate needs of operating units. Treasury also operates as central banker and provides funds to

Jan 1, 1985

By John I. Yellott

SINCE the days of Newcomen and Watt, when men first sought to turn the energy of fuels to useful purposes, coal-generated steam has supplied most of the power needed for both stationary and mobile applications. The low efficiency and large water requirements of the nineteenth century steam-power plant caused many engineers to turn their thoughts toward more direct means of converting heat into power. As far back as 1791, John Barber secured an English patent on a combination' which he might well have called a "gas turbine." He proposed to generate procducer gas from coal or charcoal, to burn it under pressure in air obtained from a reciprocating compressor, and to drive a turbine wheel with the resultant hot combustion products. With the optimism characteristic of the inventor, he hoped that the turbine would not only operate his compressor but also perform useful work. There is no record that Barber ever built his machine, but if he had done so he would have learned that useful power can result from such a combination only when both turbine and compressor are highly efficient and when the temperature of the gas entering the turbine is not far below 1000°F. Hot-air prime movers continued to attract attention, and both Stirling in England and Ericsson in America2 built reciprocating engines that operated with some success upon coal-heated air. The internal-combustion engine, burning liquid fuels, supplanted the hot-air type, and, for the first time, challenged the supremacy of both the steam cycle and its familiar fuel, coal. LIQUID FUELS COMPETE WITH COAL As the increasing use of the automobile multiplied the demand for gasoline, the supply of residual fuel increased rapidly, and heavy oil declined in price to the point where it became competitive with coal. First in the marine field and later in stationary plants in areas adjacent to refineries, oil began to be widely used. Oil's greater convenience and higher heating value per pound of weight or per cubic foot of bunker space have caused it to take over much of the marine field. The introduction of the highly efficient diesel engine, capable of burning a fuel that is cheaper than gasoline, again threatened the position of coal, for the operating costs of the diesel became directly competitive with those of coal- burning equipment. In isolated power plants and smaller marine installations, the diesel provided the medium by which oil again successfully invaded fields formerly dominated by coal. The diesel engine, provided with an

Jan 1, 1946

By E. M. Norris

During the winter and spring of 1917, an unprecedented number of underground fires occurred in the Butte district. With one exception, these fires were caused by the failure of electrical equipment, and called attention to the increased fire hazard in underground mining operations occasioned by the extensive use of electricity. Five local conditions that contributed toward a heavy fire risk were: (1) The heavy continuous timbering necessary for mine supports; (2) the strong ventilating pressures in the shafts and main airways; (3) the subsidence and faulting movements in the country rock, which ruptured cables and displaced trolley and lighting wires; (4) the strongly acid mine waters, which quickly developed any weak points in the electrical insulation; (5) oxidation in old stopes containing large amounts of timber. In the summer of 1917, a comprehensive plan of fire prevention was begun by the Anaconda Copper Mining Co., which involved a thorough and intensive development of the preventive measures then in use. These were as follows: Fireproofing, remodeling and strengthening electrical insulations, extension of underground water system, control of ' ventilation, maintaining efficiency of fire-fighting crews, and reorganization of fire patrol. In considering the problems of fireproofing, it was immediately apparent that some method of applying a durable coat of fireproof material to the mine timbers was needed. The first experiments were made with a plaster composed of one part cement, one-half part fireclay, and three parts sand. This was applied by hand to a thickness of 1 in. (2.5 cm.) over a reenforcement of herringbone metal lath. It made a very satisfactory covering for fan stations, but was too soft and friable for traveling ways, where it was subject to abrasion. The cement gun was tried next with a three to one mixture of sand and cement. A 1/2-in. coating of gunite applied over poultry netting or metal-lath reenforcement proved

Jan 1, 1923

By F. Keller, E. H. Dix, R. W. Graham

Aluminum alloys containing relatively small amounts of magnesium and silicon are of commercial interest because they are readily workable in the annealed form and may be hardened and strengthened by suitable heat treatment. An intermediate temper can be produced in these alloys by quenching after a Solution heat treatment and the alloy in this condition can be formed easily. Artificial aging is required to obtain the maximum mechanical properties but this aging does not cause distortion nor require elaborate heat-treating equipment. The hardening of the alloys after quenching is attributable in part to the retention of the compound Mg²Si in solid solution, while the maximum hardness obtained by subsequent artificial aging is attributed to the fact that the solid solubility of the compound Mg²Si in aluminum decreases with decreasing temperature. Considering the importance of aluminum alloys susceptible to heat treatment, it is surprising how few fundamental investigations have been carried out on the aluminum-magnesium silicide alloys. This paper deals principally with the solid solubility relations of the compound Mg2Si in aluminum and is the sixth paper of a series1 from the laboratories of the Aluminum Co. of America reporting the results of investigations of equilibrium relations in aluminum-base alloys made from high-purity aluminum."

Jan 1, 1931

By C. W. Vaupell

THE Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barcenite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. INTRODUCTION The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarello,2 Mactear3 and Merrill4 have described the geology and the early operations in the district, and Barcena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. LOCATION The village of Huitzuco lies in the north central part of the State of Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1937

By Hans Strack

Electroluminescence of GaAs p-n junctions fabricated by simultaneous diffusion of sulfur and iron was investigated at 77°K. A narrow emission peak with a half width of about 4 kT in the energy range between 1.14 and 1.155 eu was attributed to iron. Other transition elements exhibited light emission in the vicinity of the iron peak, namely nickel between 1.15 and 1.16 ev and cobalt between 1.16 and 1.17 ev. The efficiency of the doping with iron depended on the amoz~nt of arsenic present. A weight ratio of arsenic to iron of 4:l was sufficient to observe the emission lines associated with transition elements. The presence of oxygen reduces the intensity of the light emission. In addition to the levels associated with transition elements, levels at 1.05 and 1.28 ev, probably due to lattice defects, are observed except in diodes fabricated in solution-grown GaAs. THE near band edge emission of GaAsp-n junctions has been studied extensively in the past.' GaAs devices utilizing spontaneous and stimulated near band edge emission are of considerable practical importance. Typical junctions are fabricated by diffusion of a heavily doped p region into degenerate n-type GaAs. Much less work has been done on investigating the radiative recombination via deep levels in lightly doped p-type material. This area is of interest in understanding the performance of GaAs n-p-n transistors. GaAs transistors show remarkable improvement in high-frequency performance and current-gain stability at high temperatures, when iron is added to sulfur during the emitter diffusion process. The present work was initiated to investigate deep-level electroluminescence of iron-doped GaAs p-n junctions fabricated on vapor-phase epitaxial GaAs and on solution-grown GaAs. For comparison several diodes doped with cobalt and nickel were studied. Iron, cobalt, and nickel have an electron configuration of the type

Jan 1, 1968

By Charles S. Barrett, F. W. Steadman

Deformation bands of surprising regularity are found in large-grained poly-crystalline copper after cold-rolling (Fig. I). Individual bands frequently are large enough to permit a determination of their orientation by means of etch pits and an optical goniometer. Measurements have been made on 21 areas in seven different grains, and these, combined with X-ray studies of nine single crystals that had been cold-rolled after mounting in a polycrystal-line block, have contributed to a better understanding of the preferred orientations in rolled copper just as similar studies have for rolled iron1 and brass.2,3 Particular attention was given to determining orientations that are stable during rolling and to the manner of fragmentation and rotation of unstable grains. The possible role of twinning was also carefully investigated. The texture of polycrystalline copper after cold-rolling is well established by the pole figures that have been plotted by Schmid and Staffelbach,4 Iweronowa and Schdanow,6 and Brick and Williamson,8 all of which are in substantial agreement. There has been some divergence in the list of individual "ideal" orientations that have been used to describe the texture by these observers and others," although the orientation (110) [II2]—that is, (110) parallel to the rolling plane and [TIP] parallel to the rolling direction—is generally recognized as the most prominent orientation and (112) [III] one of the lesser orientations. Other orientations have been given by some observers as (236) [535], (100) [00I], and (110) [00I]. The texture of copper has also been described as (I35) [533].6,7 The sum of these orientations provides a reasonable approximation to the complete pole figure, but it does not follow that these specific orientations are necessarily of fundamental significance, for the choice of indices is arbitrary, within limits. Furthermore, a detailed investigation of the ideal orientations in cold-rolled iron discloses continuous ranges of equally favored positions rather than definite positions of high stability,' and similarly Brick's observations in a single crystal of a brass2 suggest that all orientations in the range between (110) [II3] and (110) [II7] are about equally stable. Materials and Methods The material used was vacuum-cast electrolytic copper kindly supplied by L. L. Wyman, of the General Electric Co.* Slicec 1/2 in. thick and 21/2 in. square, cut from the ingot, were rolled with 50 per cent reduction per pass to final thicknesses between 0.02 and 0.04 in., and etched to develop cube-face etch pits suitable for goniometric work.8 The etch was light on some strips and deep in others.

Jan 1, 1942

By Daniel N. Beshers, Ralph H. Condit

An expression for the diffusion coefficient of inlerstitial atoms in the bcc lattice is derived which takes account of jumps between tetrahedral and octahedral interstices. The results are applied to the case of carbon diffusion in iron to find values for jump frequencies of the types, octahedral-tetrahedral, tetra-hedral-tetrahedral, and tetrahedral-octahedral. ThERE has been renewed discussion1-5 concerning the mechanism of diffusion of interstitial atoms in the bcc lattice. This lattice has both octahedral and tetrahedral interstices, and it has been pointed out that the interstitial atoms may make jumps of the octahedral-octahedral type, hereafter called o-o, octahedral-tetrahedral, o-t, and tetrahedral-tetrahedral, t-t. Doubt has been cast on the applicability of snoek's8 model for internal friction to some interstitial migrations in bcc lattices wherein he proposed 0-0 jumps as the principal mechanism of migration. Also, the anomalous excess diffusion of carbon in iron at high temperatures4 has been ascribed to t-t jumps,2,3 even though the sites normally occupied are octahedral. In this paper an expression is derived for the diffusion coefficient, taking account of the three types of jump mentioned. The relationship of the coefficient to the corresponding internal friction relaxation time is found for the limiting case corresponding to Snoek's model. These results are applied to the case of carbon in iron. In Fig. 1, the structure is shown with the locations of the interstices. Each o site has four t site neighbors coplanar with it, and each t site lies halfway between two o sites. There are four t site first neighbors of a t site lying at the vertices of a tetrahedron. Let the average fraction of atoms occupying o sites and t sites be No and Nt, respectively. Since there are six o and twelve t interstices per unit cell having a lattice parameter, a, the concentration of interstitial atoms will It will be assumed that three types of jumps may be distinguished, t — t, t — o, o — t,for which the jump

Jan 1, 1968

By William F. Cerini, Willis R. Battles, P. H. Jones

A test for determining the plugging characteristics of an oil-well injection water has been developed. It consists in measuring changes of the filter rate of a water at constant pressure with cumulative throughput when passing the water through a medium grade sintered glass disk. Application of the test method was made to the water used in the Union Oil Company's experimental water flood of the Chapman zone in the Richfield field, Orange County, Callfornia. This water developed increasing plugging tendencies upon aging, even though the finished water from the plant filter exhibited few such characteristics. The plugging material was found to consist of calcium carbonate, ferric hydroxide, and organic substances that were presumed to be bacterial. Various method of stabilizing this water to prevent the formation of plugging material were attempted. Lowering the pH to approximately 6.4 by injecting carbon dioxide provided a moderately satisfactory means for stabilization but a better method of stabilizing this water was found to be first aging and then filtering. Introduction An experimental water-flood project was started on the Chapman zone of the Richfield field in March 1944 and has been described in a previous paper.' It consists of a single injection well drilled between old producing wells. A water-treating plant using primary alum flocculation, sedimentation and chlorination followed by secondary flocculation, sedimentation and fltration is employed to process the water before in@ion. In all of the water-treating operations, the system is open to the air, and no attempt is made to prevent the loss of carbon dioxide or absorption of oxygen by the water. The clear water is stored in a covered concrete basin and pumped through a Transite line to the suction of a high-pressure pump at the injection well' The high-pressure tubing in the well to the injection zone is cement lined. The untreated injection water is a mixture produced with the oil from the Chapman and Kraemer zones and is supplied from the disposal system. Because the injection well was relatively deep (injection zone about 3400 ft.) and would be expensive to replace, it was believed imperative to supply a nonplug-ging injection water and to develop laboratory procedures for evaluating the treated injection water with respect to its formation plugging properties. This report describes the development and application of the test procedure based on the assumption that the plugging properties could be determined by measuring the progressive decrease in flow rate of the water through a porous medium. If the quality of the injection water was good enough so that the plugging action on the porous medium was of small magnitude, it was reasoned that the tendency to impair flow in the formation would not be serious.

Jan 1, 1946

By Richard F. Miller

Recent studies of creep have made it apparent that plastic deformation may occur in metals under stresses less than the elastic limit as determined from short-time tests. In summarizing conclusions drawn from creep tests by various investigators, Tapselll said: "It is evident that if a material has a true elastic range, the elastic limit must represent the maximum stress for no creep." The presence of a definite elastic limit, represented in single crystals by a critical or threshold shearing stress, is claimed by Schmid2, Elam3 and others who have investigated the plastic deformation of single crystals. However, this "law of critical shearing stress" was determined2 from short-time tests, and the measurement of the deformation was made with apparatus primarily designed to observe large amounts of plastic deformation, not to detect elastic changes. Experimental data recently obtained with highly sensitive instruments by A. W. Hanson4 on zinc and by Podaschewsky5 on rock salt indicate that the elastic range in single crystals is considerably narrower than formerly was supposed. Moreover, a theoretical possibility of permanent deformation, under the influence of even the smallest shear stress in single crystals above a certain temperature (Td), has been developed by G. I. Taylor6. This evidence seemed to warrant an examination of the elastic limit in large single crystals by means of creep tests. The first metal chosen for examination was zinc. AppaRatus The creep-testing apparatus developed for this work is shown in Figs. 1 and 2. The extensometer A is sensitive enough to detect changes in length of 3.3 X 10~6 in. per in., and yet can be used into the plastic range without injury to the apparatus. The specimen,

Jan 1, 1936

By John L. Lamont, Walter Crafts

SELECTION of an alloy steel for a heat-treated article has been facilitated by methods for the calculation of hardenability,1 as-quenched hardness,2,3 and tempered tensile strength.4 Ductility and toughness may also be estimated if the steel is completely hardened on quenching,5,6 and the present study was carried out in order to develop a basis for estimating the Izod impact strength of partially hardened steel. The investigation was directed toward the prediction of Izod impact strength in steels of normal commercial quality without consideration of special compositions or heat-treatments that might produce abnormal brittleness. It was found that Izod impact strength of alloy steel is controlled by hardness, degree of hardening on quenching, and grain size. In fine-grained steels the impact strength for any given degree of hardening is inversely proportional to the tempered Rockwell C hardness, and the relation of impact strength to hardness is lowered by incomplete hardening. Calculation of the tensile strength and impact strength of heat-treating steels has shown that, except at very high strengths, tensile strength is raised by alloys without loss of impact strength whereas the tensile strength gained by higher carbon contents tends to be accompanied by a disproportionate loss of toughness. Plain carbon steels give relatively low and unpredictable impact strength. The calculation is sufficiently accurate to be helpful in the selection of alloy steel, and common grades of alloy steel have been evaluated with respect to combinations of tensile strength and impact strength attainable after heat-treatment in sections from I to 4 in. in diameter. PROCEDURE The study of the relation of hardness to impact strength was based on test data derived from 24 heats from four producers. The steels included the following SAE and AISI compositions: 1020, 1o30, 1040, 1340, 3310, 3316, 4320, 4330, 4340, 8620, 8630, 8640, 8720, 8730, 8740, 9310, 9317, 9440, 9917 and three high-alloy chromium-nickel-molybdenum steels. As far as is known, the steels tested were of normal commercial quality. They were supplied in 4-in. sections, which were forged to smaller sizes, prenormalized, and machined to final dimensions. Heat-treatment was carried out by heating to the usual austenitizing temperature for the grade of steel, holding for one hour per inch of thickness and quenching in still oil at room temperature. Previous work had indicated that this quenching treatment approximates a severity of H = 0.35. The bars were tempered as follows: ½ in., I in., and I 5/8 in., 2 hr; 2 ½ in., 3 hr; 4 in., 5 hr. All bars were air-cooled from the tempering tem-

Jan 1, 1947

By C. C. Miller, A. B. Dyes

The cost of finding and developing new reserves is continually rising. We must meet these rising costs with more economical operations. This can he accomplished if we revise our ideas of proper well spacing and well allowable to consider the concept of optimum well spacing. According to this concept, the optimum spacing is the one which leads to the maximum present worth for a reservoir when ail factors affecting total cost and total revenue are considered and when the wells are produced in the most eficient manner. Application of this principle efficiently utilizes available well potential and properly considers the recovery eficiency in addition to fixing the spacing on the basis of the amount and value of the oil to he recovered. This Study presents an analysis of one producing zone containing low gravity crude to illustrate the effect of these factors on the present worth and on the optimum economic spacing under two production drives—-evolved gas and water drive. The maximum present worth occurs when the optimum number of wells for open-flow operation is employed. Frequently, this optimum development cal1s for very wide spacing and the ideal field rates are not unreasonable. Under other circumstance. where proration is necessary, an optimum combination of well spacing and well allowable exists which permits production at relatively high rates. The optimum well density in a field depends on the recovery efficiency and the valule of the oil. In solution gas-driven reservoirs this optimum spacing for operation at high producing rates can vary from extremely wide spacing to handle viscous low gravity oil in thin formations to relatively close spacing in thick sands where good recoveries are expected. Because of the better recovery from water-driven fields, the optimum spacing in these fields is closer than in solution gas-driven fields. Also, the water encroachment pattern is dependent upon the well spacing, and an adequate numher of wells is needed to assure a good sweep eficiency. The economic optimum well density in a water-driven field is high enough for this purpose. INTRODUCTION From year to year domestic oil becomes more difficult to find. The fields we do locate are frequently smaller and deeper than older fields and the costs for men, material and equipment are continually rising. To replenish our reserves we must continue to search for and develop new fields, but experience has shown we cannot expect prices to rise in proportion to costs. Consequently, we must meet increasing costs by more economical operations. A vigorous effort is being made within the industry to improve exploration methods, to cope with the problems of deeper drilling, and to obtain a secondary yield from older fields. Many significant contributions have resulted from these efforts. The economic operation of new fields can be further improved by developing these fields on optimum spacing and producing the wells at higher rates. This would avoid the drilling of unnecessary wells and provide additional capital for seeking new oil. While the benefits of these practices are obvious, the problem of defining the optimum development of a field for natural depletion can become very complex. A study of the effect of well spacing and several reservoir variables on economic worth of a specific field is reported here to illustrate the problem and to show the magnitude of the benefits to be realized. This study is necessarily limited to the field conditions selected and is not intended as a general solution of the well spacing problem. It does, however, indicate factors to be considered, the trends to be expected, and the direction in which we should proceed in developing new fields. NO consideration is given to land and legal considerations which might arise. METHOD OF ANALYSIS The optimum method of developing and producing a field is to use the combination of spacing and prora-tion which gives the maximum return. In addition, we do not want to lose recovery. These considerations of maximum return and maximum recovery present no serious conflict. The value of each method of operation is conveniently expressed in terms of its present worth. According to the present worth method of evaluation,' an acceptable annual percentage return is assigned to the operation, and all incomes, capital costs, and expenses are discounted at this rate to the start of the operation. This net value is the present worth. If we apply the same discount rate to several alternate methods of operation, the one yielding the greatest present worth is the best method. If we express net income in terms of price per barrel of oil produced, drilling and equipment costs on a well basis, and expenses as cost per well year, this evalu-

By K. Tanaka, J. D. Mote, J. E. Dorn

It) an attempt to ulLcoce.lP the operative strain-rate-contl-olliy: dislocation nieclzanistns, specially oviented sizgle clystals of the intel-nzediate 1zexagonal phase containing Ag plus 33 at. pct A1 were tested in tension over a wide range of temperatures. Slip was observed to take place by the {0001} <1120> {l100} mechani fracture took place across the(i100) plane and winning occurred by the (i01Z) ?lechanisn. Basal slip exhibited a strong yield point over the -alzge from 77 to 450°K, the upper ,esolved shear st]-ess having the exceptionally high value of 10,500 psi over this entire ?-a?zge of tenzpei,atuves. The critical 9-esolved shear stress for prismatic slip decreased f7-om 48,000 psi at 4.3"K to 23,000 psi at 170°K (Region 1) follozcirg zt:lzich it decl>eased sloz&ly to 21,500 psi at 475°K (Res&apos;on II); from 475" to 575°K (Regioz III), the c7-itical esolced shear stress dec&apos;-eased precipitously to 2000 psi; and from 575" to 750°K (Region IV) it decreased less afi&apos;dly to a low value of about 500 psi. Pvistintic slip in Region I was pobably controlled by the tliel-nally activated riecharzisui of nucleation and g,-ozcth of kinks in dislocations lying in Peierls potential troughs. In Region II for prismatic slip the critical 1-esolved shear stress was slzocn to be deteemined by sh0l.t-range 01-dering, Overall the forgiorz fo basal slip, 7.c.lre1-e a Strong yield-point phenorlienu ia7as observed, the critical vesolved slzea?-stress was shoztn to be determined by n conibirzation 0-f Szizuki locking and short-range-order Izavderzizg, The precipitous decrease in the critical resolved shear stress with increase in ter,/pe7-atrir-e over Region HI was tentatively ascribed to a decrease in the degree of slort-)ange 07-del;iqq (0)- clusteing) and also the effect of fluctuations the degree of o?der, It is at pgreser2t zrtzce)taitz as to 1t1hethe1- these or other possi1)le effects are also ,esponsible. fo- the data obsel-ved 172 Region IV. 1NTEREST in inter metallic compounds stems not only from their role in dispersion hardening of polyphase alloy ystems but equally from their potentialities for high strength, hardness, and stability not only at atmospheric temperatures but especially at elevated temperatures. As summarized in a re- cent symposium of the Electrochemical Society on "Mechanical Properties of Inter metallic Compound", most of the experimental evidence regarding the mechanical behavior of intermetallic compounds centers about the effect of temperature on the hardness and ductility of polycrystalline specimens. The available data reveal that the plastic behavior of intermetallic compounds might be rationalized in terms of the usual dislocation mechanisms appropriate to a solid solutions providing the additional complexities arising from crystal structure, long-range ordering, short-range ordering, and defect lattices are taken into consideration. It is apparent, however, in terms of the history on a solid solutions, that a complete detailed mechanistic rationalization of dislocation processes may not be possible until the deformation processes are studied in single crystals of intermetallic compounds. The present paper contains a preliminary report on the plastic behavior of single crystals of the hexagonal Ag-A1 intermetallic phase over a wide range of temperatures. The results confirm the thesis that single crystal data provide a most effective method of identifying operative dislocation mechanisms in intermetallic compounds. EXPERIMENTAL TECHNIQUES Several factors prompted the selection of the hexagonal Ag-A1 intermetallic phase for this preliminar investigation on the plastic properties of single crystals of intermetallic compounds: 1) This phase has a wide solubility range5 which would permit future investigations on the effect of composition and axial ratios on slip mechanisms. 2) Although it undoubtedly exhibits short-range ordering (or clustering) this intermetallic phase is free from complexities arising from long-range ordering.6 3) Since the atomic radii of aluminum and silver are practically identical, the possible complications due to Cottrell locking are minimized. 4)Whereas the dislocations on the basal planes are expected to dissociate into Shockley partials and are thus susceptible to Suzuki locking, those on the prismatic planes probably remain complete. 5) The axial ratio, being 1.61, is almost ideal, suggesting that short-range ordering may be almost spherically symmetrical. The present investigation was conducted exclusively with the hexagonal Ag-A1 alloy containing 33 at. pct Al. Preliminary investigations revealed that this alloy undergoes basal slip by the (0001)

Jan 1, 1962

By D. Hnrrington

THE Dust Symposium was attended by approximately 100 persons, nearly all of whom remained from the starting hour (2 p. m.) until the use of the auditorium was demanded for another meeting at 5:30 p. in. In calling the meeting to order, D. Harrington made a few remarks as to the importance of the health dust problem in mining as well as in general industry and expressed gratification that the subject is now out in the open and that mining people are desirous of ascertaining the facts. B. F. Tillson acted as chairman of the meeting. The milling executive who desires to know what to do to prevent his workers from being unduly exposed to the dust hazard can get much out of the paper by D. E. Cummings, who has been doing much work in mines trying to keep -the dust in the air within safe limits. His recommendations indicate that the main protection of the worker in mines is by adequate ventilation, supplemented by the extensive use of water in drilling, as well as in water curtaining to condition air both in regard to dust content and to temperatures. Blasting was shown to be one of the chief causes for dust and it was recommended that whenever feasible all blasting should be delayed to the end of the working shift.

Jan 1, 1935

By I. W. Alcorn

The cost of drilling in the past few years of proration and ever decreasing allowables has received increasing thought and study. It seems to parallel the strides made with respect to pumping problems in 1932 and 1933. Low profit margins stimulate the search for economies. Any discussion of slim-hole drilling involves a multitude of abstract values, and the problem can be attacked only by a study of records and rational thinking. In a measure, traditional methods must be studied with a questioning attitude. The words "slim hole" may be somewhat misleading, as the term is entirely relative. For that reason I wish to define it as used in this discussion. On the Gulf Coast, I would define a normal hole as one in which 10 3/4-in. surface casing has been set and below which a 9 7/8-in. hole is dug. With this as a datum, holes of larger diameter below surface would be called "large holes," with 121/4 in. as the "extra large" class and holes of smaller diameter classed in the slim-hole range, 6 1/4 in. representing about the minimum size. The optimum size has not been definitely determined, but the preference is for a program that would call for setting 8 5/8 -in. surface casing and digging a 7 3/4 - in. hole. Different sections of the country might very properly deviate from this practice because of differences in depth, formations, regulations, or other factors. This paper will be confined to a discussion of the drilling of exploratory wells, as the drilling of this class of wells is quite a different problem from that of drilling a proven field, although many of the same considerations apply in both cases, as will be apparent. Although for many years shallow slim-hole and core-test holes of small diameter had been dug, it was not, I believe, until the fall of 1937 that serious consideration was given to its application in drilling wells 7000 ft., 8000 ft. and 9000 ft. deep on the Gulf Coast. This does not mean that nearly all such wells drilled on the Gulf Coast now are of the slim-hole variety, but only that efforts have been aimed in that direction with very encouraging results and there has been a very definite trend to reduce the size of holes, a trend that probably will continue. As to exploration policy, there appear to be two distinct and opposite views. The one usually followed in the past was more or less designed to "shoot the works" on one well. Generally on the Gulf Coast, the depth at which production might be obtained is limited by the drilling equipment and economics. With this thought in mind, wildcat wells are often planned with the idea of carrying the depth to 10,000 It., or even 15,000 ft. All of the possible hazards are anticipated and the general drilling and casing programs are so predicated. Such wells contemplate the drilling of large-diameter holes; the setting of at least one protective string of casing and an extensive coring policy, all of which finally adds up to an expensive well. AS opposed to this general policy is the slim hole. This, on the Gulf Coast, recognizes that new discoveries represent gam-

Jan 1, 1941

By F. B. Plummer, R. B. Newcome

The practice of introducing acid into oil wells to increase production of oil and gas has been in use since 1894, when it was first used in the Pennsylvania oil fields30.‡ It is only since 1928 that it has been used to any extent in the Mid-Continent18. The process has proved successful in increasing production, at least temporarily, in depleted oil fields where the producing formation is highly calcareous and where water drive is not too pronounced. In the Zwolle field in Louisiana, where the producing horizon is a chalk, increases of 100 per cent have been recorded25. In north-central Texas, where the oil is produced from the Marble Falls limestone, equally pronounced increases have resulted3. The production also in some fields yielding oil from quartz sand cemented with calcitc has been benefited. The evidence of actual increase in total recovery of oil, however, has been questioned by some engineers18. It has been pointed out that the results of the treatment of a well in a now district, where the process has never been tried out, can never be predicted with certainty, since other factors besides percentage of calcareous content of the oil sand play a large part in determining the success of the method. Numerous articles have been published on acid treatment and on the effects of acid on limestone1-35, yet very little has been written concerning experimental work on the actual effect of acid on capillary pores and larger oil-coated voids of oil sands. This is due partly to difficulties in duplicating field conditions in a laboratory and partly to the fact that the process has been carried out largely by contracting companies that have been unwilling to publish details of their results for fear of loss of business to competitors. The authors, using equipment developed to measure the radial permeability of oil-sand cores2&apos;, have developed a method of investigating the results of acid treatment which has enabled them to test numerous cores and to study in some detail the action of acid on the different types of rocks, particularly fine-grained rocks.

Jan 1, 1936

By Fred C. Bond

The process of comminution by grinding is properly classified as an art, rather than as a science. Like most other operations concerned in ore dressing, or in the treatment of nonmetallic minerals, the mathematical relationships of rock breaking are still obscure, and much disputed. If some basic formula exists, comparable for instance to E = RI in electricity, it has not yet been placed in common use. The absence of such a comprehensive mathematical background undoubtedly is the cause of many inefficient designs and installations, as well as of much poorly oriented experimental work. On the other hand, the mathematical immaturity of the process constitutes an opportunity for a real contribution on the part of those who enjoy mental pioneering. Some of the statements made in any such exploratory work may be little more than opinions, and it is to be expected that some will later be proved untrue; but such an evolutionary development is necessary if we are ever to arrive at the fundamental laws, the discovery of which can change the empirical art into a mathematically exact science. The most significant principle of comminution that we possess is probably Rittinger&apos;s law, which states that the work done in crushing or grinding is proportional to the area of the new surface produced. There is an alternative theory, known as Kick&apos;s law, which formerly was preferred to Rittinger&apos;s but which now is rather discredited. According to Kick, the work done in comminution is proportional to the volume, or weight, of the pieces broken, or to the cube of their diameters, while according to Rittinger it is proportional to the square of the diameters. Careful determinations of size distribution below the limit of sieve sizes1 indicate strongly that under ordinary grinding conditions the amount of new surface area produced is directly proportional to the net power input. Changes in the size ratio between the balls and the particles cause important differences in the proportion of the product that passes a given mesh size, but do not affect the total amount of new surface area; they merely change the distribution of the surface among mesh sizes. The principle of constant surface area is the logical result of Rittinger&apos;s law, and it may well have an important bearing on the comminution theories of the future. Formula for Ball Wear Grinding tests have been made in the Allis-Chalmers laboratory for more than 9 years, using a standard charge of mixed balls of different sizes; and a continuous record has been kept of the rates of wear of each size. These results have been combined and plotted in various ways in order to discover the relationship that exists

Jan 1, 1943

By F. W. Rols-Hausen, F. W. Jessen

It is the purpose of this paper to present data on brines occurring in the Frio formation of the Texas Gulf Coast, and to show how their composition varies, (1) with depth below the surface, (2) with depth below the top of the formation, and (3) along the approximate strike. The brines vary in chloride content from 3,180 to 73,000 p.p.m., though the average salinity of the salt waters is shown to vary with total depth; the concentration being 35,000 to 40,000 p.p.m. at 3500 to 5500 ft., slightly less than 50,000 p.p.m. chloride at 5500 to 6500 ft. and average 38,000 to 40,000 below 6500 feet. From the analyses available, it appears that the highest concentration of salts occurs in the upper 300 ft. of the formation, while lower salinity is found with increasing depth below this point. The salt waters from wells in Starr County show less concentration of dissolved salts than in any other group of wells farther north along the strike. In all, 116 analyses from 63 fields and 14 wildcats, from depths ranging from 1300 to 11,400 ft. below the surface and from z to 3240 ft. below the top of the Frio, are recorded. Introduction Brines have been studied for many Years in an attempt to solve some of the geologic and production problems associated with the production of oil and gas. One practical application of study of . water analyses is the correlation of waters occurring above, in, or below the producing sand in the same field or throughout the same formation. The Frio formation, the series of sands and shales occurring below the Marginulina zone and above the Vicksburg, is one of the major oil and gas-producing formations in the Texas Gulf Coast. Fossils are rare or absent in the upper Frio throughout most of the area. When available, cuttings and cores, and electric logs were used to determine the top of the Frio. A change in lithology was used to determine this point in most of the wells, and fossils were used in some of the deep wells. It is realized that a change in lithology is not perfect for correlation purposes over long distances and some of the trends may be influenced by the inability to differentiate between the nonfossiliferous Marginulina zone and the Frio. It underlies virtually all the area shown on the accompanying map (Fig. I). Although it is not productive in the updip facies, it has been explored to a limited degree below I2,000 ft. Further more, toward the coast line future drilling to deeper depths should encounter this formation. Although thousands of wells have penetrated or drilled entirely through the formation, very few water samples have been secured from the many sands occurring in this formation and analyzed. Previous Investigation No previous published study has been made of the chemical composition and concentration of waters from the Frio formation. However, one water analysis

Jan 1, 1944

By Arthur Boynton

IN THE preparation of this paper the writer has been influenced by the fact that descriptions of various means of cleaning blast-furnace gas have been published and that further descriptive treatment of the subject will probably be less interesting than a statement of conclusions with regard to preferable methods which have been reached by him as a result, of experience and observation in this country and also as a result of somewhat detailed investigation of the subject made toward the end of the year 1927 on the Continent of Europe and particularly in. Germany. Owing to various circumstances, including a cost of fuel that is extremely high in relation to the wages of labor, the German iron and steel industry has accumulated experience in gas washing which is as yet in part lacking in the United States of America. The paper begins with a statement regarding the economics of the use of blast-furnace gas, then considers the principle&apos;s and practices employed in its purification. USES OF BLAST-FURNACE GAS For many reasons having to do with the utilization of coke-oven and blast-furnace gases in steel manufacture and with the use of hot metal, the blast furnace is now usually a part of a steel-producing unit, which also includes coke plant and rolling mill. Therefore both blast-furnace and coke-oven gas are usually applicable to any of the iron and steel-making processes, including the generation of power, and their allocation in any given works should be considered as a single problem. The uses to which blast-furnace gas, either alone or mixed with coke-oven gas may be put, include the following: Regenerative Heating of Air for the Blast Furnace.-This is the oldest and metallurgically the most important of all uses. It is universally performed with unmixed blast-furnace gas and under proper conditions should require not over 23.5 per cent. of the total gas generated for a blast temperature of 1350° F. For Steam-raising Purposes.-This is almost universally done with unmixed blast-furnace gas. From the standpoint of quantity used, it is at the present time the most important application in American steel-works practice.

Jan 1, 1928

By E. V. Watts

The D-7 zone of the Ventura Avenue field is of special interest because the initial reservoir pressure at 92.00 ft nearly equaled the pressure exerted by the overburden. While the phenomenon has been observed elsewhere in the world, there is no record of a previous case in California. Such high pressures have been attributed to sealing of the reservoir, followed either by emergence of the beds or by compaction of the sediments in various ways. Oil in the D-7 zone is undersaturated. At pressures above the bubble point, oil is recovered by the slight expansibility of the reservoir framework and its liquid contents. More than 40 pct as much oil probably will be recovered by this mechanism as will be recovered by internal gas drive after pressures pass below the bubble point. Operations are handicapped by sand and pipe troubles. Introduction The Ventura Avenue field has been under development since 1915. It has long been considered a "high-pressure" field, but interest was heightened by the extreme conditions encountered in the recent development of the so-called D-7 zone. The original reservoir pressure in this pool is estimated to have been 8300 psi at a depth of 9000 ft below sea level, or 9200± ft below the surface. A fluid pressure approaching that exerted by the overlying sediments has been encountered in other parts of the world, but never before in California to the degree observed in the D-7 pool. With few exceptions, the original pressure in California fields is about equivalent to the static head of water below the water table in the outcrop. Structure The Ventura anticline is a prominent feature of the Ventura basin, being traceable on the surface about 17 miles.&apos; The Ventura Avenue field is at the apex of the anticline. It is about one mile wide and five miles long, the major axis lying in an east-west direction. The productive limits cover an area of about 2300 acres. The entire anticline has been severely folded and faulted. The productive portions in particular are broken up by three major thrust faults having a general east-west strike. The resultant four fault blocks are termed the A, B, C, and D blocks, respectively. Certain electric-log intervals are assigned numbers. Fig I is a diagrammatic north-south section of the field near the crest, looking west, and shows three of the four fault blocks. To the west, the upper fault divides into two branches, which define the B block. Wells penetrating a fault may duplicate over 1000 ft of formation. However, the greater fault movement is the strike shift, which is believed to exceed 2500 ft both between the A and C blocks and between the C and D blocks. The location of water is irregular and unpredictable. A few intermediate waters exist, while some strata have more than 2000 ft of productive closure.

Jan 1, 1948