Search Documents

By Albert F. Hill

The manufacture of structural shapes in steel of uniform quality, which shall command the full confidence of the engineer, is a problem in practical metallurgy which is beginning to attract much attention in this country. The progress of the past fern years in the improvement of plant and processes has placed it within the power of the steel-maker to supply a material of such chemical composition as will meet the requirements; but this solves only in part the difficulties of the constractor. It is well understood that the influence of shop manipulations is a most decisive one upon the mechanical properties of the finished product; in many cases so great, in fact, as to cause an entire transformation in the character of the material, and to render it unfit for the service for which it was intended. On the other hand, mechanical treatment is frequently resorted to as an efficient corrective of certain undesirable properties, which may be due either to chemical composition or previous manipulation. This understood and accepted, it is evident that careful investigation of the effects of mechanical treatment is fully as necessary to the successful use of steel in engineering structures, as the investigation of the influence exerted by its chemical composition. All structural material has to undergo more or less mechanical treatment, such as shearing, punching, upsetting, etc. Each of these operations produces effects which are far more marked and decisive in steel than they are in iron, and means must therefore be adopted to counteract, or at least to modify, these effects before the material is permitted to enter the structure. The fact that both shearing and punching affect the tenacity and elasticity of steel has long been recognized; bat, through more recent investigations, it has been established that these effects are purely local, and are therefore susceptible of correction by other and simpler means than annealing. The importance of this discovery to the use of steel in structures is very great. The impracticability of

Jan 1, 1883

By C. A. Heiland

Measurements of gravity with gravimeters have come into increased use in this country and abroad in the past five years. Probably 100 to 125 gravimeter parties are working in the United States alone. In oil exploration, gravimeter methods have relegated the gravity pendulum definitely to second place, if not third, and now closely rival and possibly surpass the torsion balance in many applications. Gravimeters have lately been applied in mining, although it is doubtful whether they will ever replace electrical or magnetic methods in this work. Notwithstanding the widespread application of gravimeters, there has been no article covering the entire field in the domestic or foreign literature. The purpose of this paper is to meet the demand for comprehensive engineering information on the subject. The working principles of a number of gravimeters will be illustrated and treated in relation to the action of corresponding seismometers and astatization methods. The mathematical discussion of theory has been confined to the most necessary fundamentals and been given in as elementary form as possible. A description of calibration methods constitutes the last part of the paper. The symbols shown at the top of page 197 will be used in equations throughout the paper. Dynamic and Static Gravity Methods Methods of measuring gravity fall into two groups: dynamic and static methods. The first group involves the measurement of time. Examples are: determinations of the period of oscillation of a pendulum, measurements involving the free fall of a body, and comparisons of gravity with the centrifugal force of a rotating body. Measurements in the second group of gravity methods are concerned with deflections of certain indicators when the force of gravity is in equilibrium with another comparison force.

Jan 1, 1940

By C. A. Heiland

Measurements of gravity with gravimeters have come into increased use in this country and abroad in the past five years. Probably 100 to 125 gravimeter parties are working in the United States alone. In oil exploration, gravimeter methods have relegated the gravity pendulum definitely to second place, if not third, and now closely rival and possibly surpass the torsion balance in many applications. Gravimeters have lately been applied in mining, although it is doubtful whether they will ever replace electrical or magnetic methods in this work. Notwithstanding the widespread application of gravimeters, there has been no article covering the entire field in the domestic or foreign literature. The purpose of this paper is to meet the demand for comprehensive engineering information on the subject. The working principles of a number of gravimeters will be illustrated and treated in relation to the action of corresponding seismometers and astatization methods. The mathematical discussion of theory has been confined to the most necessary fundamentals and been given in as elementary form as possible. A description of calibration methods constitutes the last part of the paper. The symbols shown at the top of page 197 will be used in equations throughout the paper. Dynamic and Static Gravity Methods Methods of measuring gravity fall into two groups: dynamic and static methods. The first group involves the measurement of time. Examples are: determinations of the period of oscillation of a pendulum, measurements involving the free fall of a body, and comparisons of gravity with the centrifugal force of a rotating body. Measurements in the second group of gravity methods are concerned with deflections of certain indicators when the force of gravity is in equilibrium with another comparison force.

Jan 1, 1940

By Reinhardt Thiessen

UNDER sulfur in coal, is usually understood that form of sulfur which is combined with iron and known as pyrite. It occurs in the form of halls, lenses, nodules, continuous layers, thin sheets, or flakes, both in horizontal planes and vertical cleavage fissures. But pyrites also occur as very fine microscopic particles, or nodules, disseminated through the compact coal. This form has had but very little consideration. Finally, there is sulfur in coal in an amicroscopic form (not visible with an ordinary microscope), probably combined with the organic matter that exists -in tile coal. This form has had considerable attention from a scientific standpoint, but has probably not been recognized enough on the economic side. One or the other, or both, of these two latter forms may comprise the larger part of the sulfur content of coal, especially after it has been washed or otherwise prepared for use.

Jan 9, 1919

By Ashok K. Sinha

The quasi-binary systems "VFe3"—VCo,—VNi,— "VCu3"and "TiFe3"—TiCo3,—TiNi3-"TiCu3"have been studied by a combination of microscopic and X-ray methods. Of the Phases encountered, eleven had close-packed ordered layer structures. Within each system, there is an approximately linear variation of the degree of hexagonality of the stacking arrangement with electron concentration, e/a. A study of eighty -four known examples of AB3 structures in transition metal alloys indicates that at e/a = 8.65 the ordered structure of the close -packed layers changes from "triangular" (AuCu3 type) to "rectangular" (SbCu3 type). At e/a < 8.65, the slope of hexagonality us e/a line increases with the group number of the A component. An interesting series of close-packed ordered structures is known to exist at the composition AB3; however, their alloy chemistry has not yet been fully understood. Dwight and Beck1 observed a correlation between position of the components in the periodic table and the type of crystal structure of the binary AB2 structures formed by transition metals. No consistent effect due to atomic size was noted and they proposed that electron concentration* predominates in In the present paper, the AB3 structures are characterized by a symbol describing the stacking and a symbol specifying the ordered layer. The stacking symbol used was introduced by Zhdanov,7 and later used in the International Tables,8 and by Beck9 in his survey of possible layer stacking structures. Alternating positive and negative integers are used to represent the number of positive (e.g., in abcabc...) and negative (e.g., in cbacba...) stacking sequences. T denotes the triangular ordering found in close-packed planes of the AuCu3 structure and R the rectangular ordering found in close-packed planes of the SbCu3 structure, Figs. 3(a) and (b). The present structure symbols are listed in Table I alongside the prototypes, where known, and other structural characteristics of AB3 phases found in the present investigation. EXPERIMENTAL The starting materials were metals of 99.9+ purity. The alloys were prepared by arc melting under argon atmosphere using a nonconsumable tungsten electrode and water-cooled copper hearth. The total weight loss upon melting and subsequent annealing was always less than 0.5 pct and hence the alloys will be referred to by their intended (unanalyzed) compositions. The alloys were homogenized and annealed at suitable temperatures in the range 750" to 1200°C, the annealing periods varying from 3 days at 1200°C to 10 days at 750°C. The heat treatments were carried out in sealed silica capsules under argon atmosphere and with a molybdenum foil cover between the alloy and the walls of the capsule. The quenched alloys were microscopically examined and reduced to powder by crushing or filing. The powders were, whenever necessary, given a stress-relieving anneal at the original annealing temperature. X-ray powder patterns were obtained with an asymmetrical focusing camera, a Guinier-deWolff focusing camera, or a Debye-Scherrer camera. Cr, Co, or Cu radiations were used. In some cases, to ensure the minimum degree of contamination, the deeply etched specimens were mounted in the asymmetrical focusing camera to obtain an X-ray pattern. Internal silicon standards were employed for lattice parameter determinations. The intensity calculations were made by using a Fortran IV program

Jan 1, 1970

By D. E. Menzie, D. L. Dauben

This paper discusses the physical parameters involved in the slow flow of high molecular weight polymer solutions in porous media. The interacting effects of polymer properties and porous media properties on flow performance are considered. Experiments were conducted with the polyethylene oxides, with molecular weights ranging from 200,000 to over 5,000,000. Frontal advance velocities ranged from I to 30 ft/day. The porous matrix consisted of a flow cell packed with glass beads. Polymer solutions were characterized by viscosity and normal stress measurements. Under certain conditions, unexpectedly high flow resistance was observed. This behavior was observed to be a function of flow rate, pore size, polymer molecular weight and concentration. The polymer solutions exhibit "dilatant" flow behavior in porour media in contrast with the pseudo-plastic behavior in simple flow systems. A theoretical ex-planation of such behavior is presented. INTRODUCTION The use of polymers in the injected water of a waterflood increases oil displacement efficiency by reducing the mobility (k,/pu) of the driving phase. A reduced driving phase mobility results in improvements in the areal sweep efficiency and in the vertical coverage in stratified reservoirs. This mobility reduction may be achieved by a permeability reduction, a viscosity increase or by a combination of the two. Early attempts at increasing the injected water viscosity were not successful because of the poor economics involved. The use of such materials as glycerin, sugar or glycols to increase water viscosity was not economically feasible. Attempts in using certain naturally occurring polymers were not too successful because of the high polymer losses to the rock. A high molecular weight, partially hydrolyzed polyacry-lamide was introduced 3 years ago as a waterflood additive.&apos;,&apos; Initial work by Pye&apos; indicated that the presence of these polymers in dilute concentrations decreases the water mobility 5 to 20 times more than would be expected from measurements of the solution viscosity. Such an effect would be of obvious economic value since only a small polymer concentration would be required to accomplish a large reduction in water mobility. This research was designed to study the basic flow mech anisms of polymer solutions in porous media. The interacting effects of polymer properties and porous media properties on flow performance are considered. This study indicates some of the conditions under which these interactions can lead to significant mobility effects. is valid only for Newtonian fluids. For polymer solutions and other non-Newtonian fluids the equation must be modified to consider that viscosity is a variable quantity. Modification of the Darcy equation to include non-Newtonian effects has been the subject of several recent investigations."" The modifications generally adopt a rheological model. such as an Ellis or Dower law model. to Dorous media by defining some characteristic channel radius. Most of these studies showed the porous media flow behavior to be predictable from viscometric data. Investigations involving the flow of high molecular weight polyacrylamide solutions through cores have generally encountered the high flow resistances reported previously by Pye. This high flow resistance has generally been attributed to an in-depth permeability reduction, as evidenced by a reduced permeability to water which has displaced polymer solution from the porous media. Marshall and Metzner" report high flow resistances, which they attribute to viscoelastic effects. In this paper, the effects of polymer molecular weight, pore size, flow rate and concentration are considered. The polymers used are the polyethylene oxides known as Poly-ox. This class of polymers was used because of its availability in a wide range of molecular weights and because of its known ability to propagate well through porous media. THEORY PHYSICAL PROPERTIES OF POLYMER SOLUTIONS The polymer molecule dissolves in water by means of hydrogen bonding, but retains some of its own structural identity while in solution. Nonionic polymers, such as polyethylene oxide, are generally considered to have a random coiling configration. This type of molecule has the ability to "sequester" or hold a large volume of solvent within its coils in a manner similar to that of a sponge. The random coil is easily deformed and under an applied stress

By E. G. Bailey

PLANTS that normally burn coal now able too obtain a substantial increase over their normal supply for their greater power needs, and also additional tonnage for extra storage against the uncertainties of the future. Many plants previously burning oil or gas have already been converted to coal, and those which must yet change to coal will undoubtedly be able to obtain ample tonnage of coal of standard quality at reasonable prices. What a contrast this is to the conditions of 25 years ago, when the shortage of coal and transportation led to prices of $5 to $6 per ton at the mines, and degradation of quality, until the already overburdened railroads were called upon to haul 100,000 ton per day of extra ash alone. This was the result of a runaway market and the loading of gob, slate, and sub-quality coal amounting to an estimated increase in ash of 5 per cent of the total tonnage hauled. The problem of getting increased steam output from inferior coal caused unbelievable reductions in the low normal boiler efficiency of that time and untold labor in firing the hand- and stoker-fed furnaces of that day.

Jan 1, 1942

By J. C. Febles

HISTORY. THE use of iron for the precipitation of copper was known at least as early as the fifteenth century. Both Paracelsus and Basil Valentine refer to it in their writings, as early as 1500 A. D. It was used in Peru, for this purpose prior to 1637, and at Rio Tinto, Spain, as early as the sixteenth century. The statement has been made repeatedly that in the early history of the mining industry at Butte, the practicability of this method of recovering copper from solution was overlooked, and that enormous quantities of copper-bearing water were allowed to go to waste, the copper in which might easily have been recovered at small cost; and that this oversight on the part of the mine operators was due to ignorance of this method of recovering copper. As a matter of fact, very little copper-bearing mineral was encountered in the mines of Butte until a depth of 400 or 500 ft. bad been reached, and in many cases much greater depths were necessary to reach the copper-bearing zone. The water encountered in the upper levels (although in most cases quite highly mineralized) contained little or no copper, and it was only after considerable areas of copper-bearing ore had been uncovered and developed that copper sulphate began to. appear in the mine water in any considerable quantity. In fact, the first water that was observed to contain copper carried it in such small amounts as to be of little or no importance. It was only after years of underground work had opened extensive areas of stopes, drifts, and other underground workings, these being subsequently filled with waste, nearly all of which contained small copper values, which became oxidized by exposure to the air and were acted upon by the slowly percolating mineral water, that the recovery of copper from mine water became commercially important.

Jan 7, 1913

By Paul T. Allsman, E. W. Newman

Trenching, sampling, and core drilling in Stillwater and Sweetgrass Counties, Mont., by the Bureau of Mines have delimited over 5,000,000 tons of chromite ore containing more than 20 per cent chromic oxide. The Benbow and Mouat-Sampson mines have been developed and are fully equipped for mining and milling 500 tons and 2000 tons a day, respectively. Introduction The Montana chromite deposits were the first to be explored under the Strategic Minerals Act of 1939. In June of that year, the Bureau of Mines started exploration by trenching, test pitting, sampling and diamond drilling, and completed the project in March 1943. The U. S. Geological Survey cooperated by mapping the geology and logging the cores. The project was to determine the extent and grade of the chromite ore and to indicate sufficient reserves to justify development and exploitation of the deposits for the national emergency. Exploration has indicated that the district contains the largest and most important reserve of chromite ore in the United States. The Benbow and Mouat-Sampson mines have been developed and a 500-ton concentrating mill has been constructed on the Benhow property and a 2000-ton mill on the Mouat-Sampson property. Concentrates were produced from the Benbow mill three months after the attack on Pearl Harbor, when the nation&apos;s major chromite supplies from foreign sources were cut off. History It has been known for 50 to 60 years that some chromite deposits existed in an east-west belt along the north escarpment of the Beartooth Mountains about 25 miles north of Yellowstone Park, but nothing was known of their size and extent until the war demand of 1917 and 1918 stimulated the search. In those years two properties in the Stillwater region were actively developed, but no shipments were made. The Benbow property was located in 1918 by a local group. The property comprised seven claims along the strike at the east end of the belt. An adit was driven several hundred feet on the Eclipse claim. The seven claims were sold to the Chromium Products Corporation of Livingston, Mont., and were subsequently patented. In 1929, an eastern group obtained an option, installed some equipment, and erected several log cabins. The "crash" in the market in 1929 caused the operators to drop their lease, and the property remained inactive until 1939, when the Bureau of Mines began its exploration. Fourteen claims were located on the Boulder River in 1918 and subsequently patented by the U. S. Chrome Corporation.

Jan 1, 1949

By Paul T. Allsman, E. W. Newman

Trenching, sampling, and core drilling in Stillwater and Sweetgrass Counties, Mont., by the Bureau of Mines have delimited over 5,000,000 tons of chromite ore containing more than 20 per cent chromic oxide. The Benbow and Mouat-Sampson mines have been developed and are fully equipped for mining and milling 500 tons and 2000 tons a day, respectively. Introduction The Montana chromite deposits were the first to be explored under the Strategic Minerals Act of 1939. In June of that year, the Bureau of Mines started exploration by trenching, test pitting, sampling and diamond drilling, and completed the project in March 1943. The U. S. Geological Survey cooperated by mapping the geology and logging the cores. The project was to determine the extent and grade of the chromite ore and to indicate sufficient reserves to justify development and exploitation of the deposits for the national emergency. Exploration has indicated that the district contains the largest and most important reserve of chromite ore in the United States. The Benbow and Mouat-Sampson mines have been developed and a 500-ton concentrating mill has been constructed on the Benhow property and a 2000-ton mill on the Mouat-Sampson property. Concentrates were produced from the Benbow mill three months after the attack on Pearl Harbor, when the nation&apos;s major chromite supplies from foreign sources were cut off. History It has been known for 50 to 60 years that some chromite deposits existed in an east-west belt along the north escarpment of the Beartooth Mountains about 25 miles north of Yellowstone Park, but nothing was known of their size and extent until the war demand of 1917 and 1918 stimulated the search. In those years two properties in the Stillwater region were actively developed, but no shipments were made. The Benbow property was located in 1918 by a local group. The property comprised seven claims along the strike at the east end of the belt. An adit was driven several hundred feet on the Eclipse claim. The seven claims were sold to the Chromium Products Corporation of Livingston, Mont., and were subsequently patented. In 1929, an eastern group obtained an option, installed some equipment, and erected several log cabins. The "crash" in the market in 1929 caused the operators to drop their lease, and the property remained inactive until 1939, when the Bureau of Mines began its exploration. Fourteen claims were located on the Boulder River in 1918 and subsequently patented by the U. S. Chrome Corporation.

Jan 1, 1949

By D. J. Carney, E. Van Meter, J. J. Oravec

A study was made of combustion-air temperatures and factors affecting air temperatures in the open-hearth regenerative systems. Air-temperature surveys in the regenerative system revealed marked thermal gradients in the air above the checkers. The design of the fantail-uptake region plays a prominent part in increasing the heat recovery of the regenerative system. THE efficiency of the open-hearth regenerative system is one of the most important factors affecting open-hearth performance. Until recently, this factor has not received the attention in the literature given to many other items affecting performance, such as the type of charge, speed of charging, and the mechanical equipment of the open hearth. J. S. Marsh&apos; emphasized the importance of the flame temperature and its dependence upon the combustion-air temperature. By means of measured air temperatures in open-hearth furnaces, data were presented which showed a remarkable degree of correlation between production rate and combustion-air temperature. This correlation was extremely good in view of the numerous factors, other than air temperature, which affect open-hearth production rates. In Marsh&apos;s work, a 100°F increase in air temperature reduced the heat time by approximately 45 min. Realizing the importance of combustion-air temperature, it is desirable to know which factors control the regenerative efficiency of the open-hearth furnace. B. M. Larsen recently discussed this subject.&apos; The present paper illustrates a few of the more important items that affect regenerative efficiency and combustion-air temperature. In the latter part of 1951, a study of open-hearth combustion-air temperatures was begun at the South Works of the United States Steel Corp. In the initial work at open-hearth shop X, which produces low carbon steel products, temperatures were measured in the uptake in a manner similar to that used by Marsh&apos; and the results obtained were very similar to the Bethlehem data. When it was decided to expand the study of combustion-air temperatures, open-hearth shop Y was selected because of the greater variety of furnace-design features, types of steel produced, and firing rates used. With the use of aspirating thermocouples, continuous gas analyzers, thermocouple and optical pyrometers, a study was made of: 1—effect of combustion-air temperature on open-hearth production rate, 2—thermal gradients present in various zones of the regenerative system, 3—effect of furnace-design variations on air temperature and heat recovery, 4-—effect of furnace-operating variables on heat recovery, and 5—variation in heat recovery with furnace age during the normal furnace campaign. Data collected on individual heats at 15 min intervals included air-flow rate, firing rate, checker temperature, combustion-air temperature, and furnace pressure. These data were collected on approximately 230 heats of steel. In addition, information was obtained at random on air infiltration and combustion-gas compositions. The data gathered have shown the desirability of closer control of open-hearth firing practices, a need for reducing air infiltration in the uptake zones, and a need for further study of design of checkers and of uptake-fantail areas. Equipment Air is practically a nonradiating medium. Consequently, in the measurement of air temperatures, the principle of heat conduction must be used rather than heat radiation. For this reason, aspirating-type thermocouple pyrometers normally are used to measure air temperatures. With these devices, air

Jan 1, 1956

By Charles C. Russell, Glenn C. South

A primary factor in the selection of coals for making coke at high temperatures is the amount of pressure the coal will exert upon the oven walls when carbonized in modem by-product ovens.l-3 This factor has become increasingly important in recent years because of demands for increased throughput and higher coke yields. As a result of the increasing necessity for assessing coals in regard to their carbonization pressures, more and more research work is being directed toward developing labora-tory-scale tests for predicting carbonization pressures and for showing how blends of coking coals may be modified to eliminate pressures liable to damage coke-oven walls. The specific reasons have never been defined as to why some blends of coking coals develop dangerous carbonization pressures and others do not, therefore specific procedures to eliminate dangerous pressures could not be prescribed. It is true that the major processes occurring during carbonization have been described by many writers,4 and there is a general agreement on the ideas of the changes that occur as coal is transformed into coke. However, there is little evidence relating the processes occurring during carbonization to the pressure developed and the available evidence is very incomplete and often contradictory. This deficiency arises in part from the fact that the fundamental causes of pressure development have not been defined, at least from experimental data, and in turn this is the result of the lack of satisfactory testing equipment for studying the problem. Operating experience has shown several ways of reducing or eliminating dangerous pressures,5 but probably none of these ways is applicable to all blends of coking coals, and such empirical methods often lead to production of inferior coke. They are trial-and-error methods, not designed to remedy specific causes of pressure development. The number of laboratory-scale testing devices designed to estimate the carbonization pressures that result when coals are carbonized in commercial ovens is probably well over a hundred.6 Few of these instruments have remained in use for any length of time, either because the predictions were not sufficiently accurate or, more often, because too many exceptions were found. Often testing devices are operated without any attempt at duplication of conditions in commercial ovens and erroneous and contradictory results are frequently obtained. Therefore, it has seemed desirable to study the properties of coal itself and to determine any relationships between the properties of the coal and the carbonization pressures developed. Relationship between Properties of Coal and Carbonization Pressure Attempts to determine relationships between various properties of coal and carbonization pressures, for the most parti have been indirect because no satisfactory and reliable laboratory testing device has

Jan 1, 1944

By Glenn C. South, Charles C. Russell

A primary factor in the selection of coals for making coke at high temperatures is the amount of pressure the coal will exert upon the oven walls when carbonized in modem by-product ovens.l-3 This factor has become increasingly important in recent years because of demands for increased throughput and higher coke yields. As a result of the increasing necessity for assessing coals in regard to their carbonization pressures, more and more research work is being directed toward developing labora-tory-scale tests for predicting carbonization pressures and for showing how blends of coking coals may be modified to eliminate pressures liable to damage coke-oven walls. The specific reasons have never been defined as to why some blends of coking coals develop dangerous carbonization pressures and others do not, therefore specific procedures to eliminate dangerous pressures could not be prescribed. It is true that the major processes occurring during carbonization have been described by many writers,4 and there is a general agreement on the ideas of the changes that occur as coal is transformed into coke. However, there is little evidence relating the processes occurring during carbonization to the pressure developed and the available evidence is very incomplete and often contradictory. This deficiency arises in part from the fact that the fundamental causes of pressure development have not been defined, at least from experimental data, and in turn this is the result of the lack of satisfactory testing equipment for studying the problem. Operating experience has shown several ways of reducing or eliminating dangerous pressures,5 but probably none of these ways is applicable to all blends of coking coals, and such empirical methods often lead to production of inferior coke. They are trial-and-error methods, not designed to remedy specific causes of pressure development. The number of laboratory-scale testing devices designed to estimate the carbonization pressures that result when coals are carbonized in commercial ovens is probably well over a hundred.6 Few of these instruments have remained in use for any length of time, either because the predictions were not sufficiently accurate or, more often, because too many exceptions were found. Often testing devices are operated without any attempt at duplication of conditions in commercial ovens and erroneous and contradictory results are frequently obtained. Therefore, it has seemed desirable to study the properties of coal itself and to determine any relationships between the properties of the coal and the carbonization pressures developed. Relationship between Properties of Coal and Carbonization Pressure Attempts to determine relationships between various properties of coal and carbonization pressures, for the most parti have been indirect because no satisfactory and reliable laboratory testing device has

Jan 1, 1944

By Barbara A. Thompson

A previously reported high-resolution method for the location of boron-rich areas in metallurgical and biological specimens was been adapted for general use on a routine basis. The rnetlzod utilizes neutron activation and autoradiograpizy. Alpha-particles emitted by boron nuclei upon neutron capture are recorded on a photographic emulsion. The resulting a-particle tracks show the location of boron-rich areas. Experimental techniques, interferences, and limitations of the method are discussed in detail. The method is most useful where there is marked segregation of boron. In this type of sample, the segregation can be observed when the nominal boron concentration is as low as 0.0006 pct. THE positive identification and location of boron-rich areas in metals is frequently of great interest in metallurgical work. Unequivocal identification is often difficult to make by conventional metallo-graphic methods. Recently, a method has been described which accomplishes this objective by neutron activation and autoradiography.l-3 The method can be described briefly as follows. Upon neutron capture, a -particles are emitted by boron nuclei according to the following reaction: ,Blo + n - ,a4 + 3Li7 + 2.4 mev The energy is dissipated as kinetic energy of the products. By irradiating a boron-containing sample in contact with a photographic emulsion and subsequently developing this emulsion, a-particle tracks are obtained whose location corresponds to the location of boron-rich areas in the sample. Two factors combine to make the reaction extremely specific for boron. The first is the unusually high (755 barns) cross section of boron for thermal neutron capture. The second is the higher neutron energy required to produce (n, a ) reactions in essentially all other nuclei except lithium. These two factors make the method specific for boron by six to seven orders of magnitude when a predominantly thermal neutron source such as the Brookhaven reactor is used. The reported limit of detection of this method is of the order of 0.01 pct B., The present work was originally undertaken to determine whether this limit could be lowered by use of a thinner emulsion. However, initial experiments showed that in order to use the method at all, it was necessary to reestablish the optimum experimental conditions in terms of the available irradiation facilities. It is the purpose of this paper to describe these experimental conditions in detail, to discuss the factors influencing sensitivity, and to evaluate several techniques for increasing sensitivity. EXPERIMENTAL A) Preliminary Experiments—The first measure-ments were made using samples of crystal oriented silicon steel containing various concentrations of boron. In the later experiments, samples of various high-temperature alloys such as M-252, hcoloy 901, Nichrome V, and so forth, were used. Faraggi, et al.,2 reported that the lower limit of sensitivity in this type of sample was about 0.01 pct B using nuclear emulsions of 50- u thickness. but that it should be possible to extend this limit by the use of thinner emulsions. Accordingly, we first used Kodak Auto-radiographic Stripping Film (Permeable Base) which has an emulsion thickness of only 5 µ. This was mounted on the metallographic specimens according to the technique described by Boyd.4 The emulsion remained in contact with the metal surface throughout exposure and development. Since the emulsion is transparent after development, the autoradiograph and metal surface can be viewed simultaneously and any correlation between film blackening and structure of the metal can be made directly with no problems of realignment. Because the silicon steel is readily attacked by moisture alone, it was necessary to apply a protective coating to the metal surfaces before mounting the emulsion. The coating was made extremely thin in order to absorb as few a-particles as possible. Boyd4 and Gomberg5 have discussed various plastics used for this purpose; however, none was sufficiently impermeable to prevent chemical attack of the steel during the developing process. This attack resulted in the production of gross chemical artifacts in the emulsion. It was, therefore, necessary to use the method of Wolfsberg and John6 as follows. A very thin (approximately 1 µ) coating of Plexiglas II was applied by dipping the sample in a 2 pct solution of Plexiglas II in dichloroethylene. Then, because the emulsion will not adhere to Plexiglas 11, a thin coating of Parlodion was applied in a similar manner using 2 pct Parlodion in iso-amyl acetate. No protective coating was necessary with the high-tem-

Jan 1, 1961

The Honor Roll includes the names of all members of the Institute Whom we know to have been on active military duty it the date of compilation, Mar. 5, 1919. Despite our efforts to have this list accurate and complete, some of our members who have been rendering military service are probably left off because of the fact that we have not been informed of their military connection. The list of men in military service has been compiled with great difficulty owing to the modesty of the members, who in their patriotism began their service but neglected to send us notice. In 1918, We published a separate Honor Roll of the Institute in which we included a list entitled "On active duty in other departments of the service" which contained the names of members who were rendering important emergency service to the Government other than in the Army. This list is entirely omitted this year because any list We might compile for this purpose would be entirely inadequate and must inevitably do injustice to a large number of our members who have been devoting great time and making many sacrifices for the benefit of the government along lines not within our ken. It is not too much to say that almost all our membership in this country has been, more or less directly, doing its uttermost for the successful prosecu¬tion of the war. The active work of many of these members we are Well aware of, as is also the rest of the civilized world. Faithful and wholehearted efforts on the part of many other members we have not been informed of, so that any list would be both incomplete and unsatisfactory.

Jan 1, 1923

By N. J. Grant, E. Gregory

The creep rupture properties of wrought aluminum powder products made from five grades of sintered aluminum powder were investigated at temperatures from 400° to 900°F for rupture times up to 1000 hr. The effect of stress concentrations on materials of this type was investigated by means of notched creep rupture tests. A tentative correlation was obtained between the creep rupture properties and the structure as revealed by electron micrographs. SEVERAL papers have been published recently concerning the production and properties of wrought aluminum powder products and their possible high temperature applications. Most of the published work in this field has come from abroad, notably Switzerland, and articles by Irmann and his colleagues were summarized in English recently.&apos;.&apos; Most of the papers published by Dr. Irmann are principally concerned with the retention of properties (by a product which is produced from extremely fine flake powder and is subsequently hot extruded) after heating to high temperature for prolonged times. The powder may be in atomized or flake form, and during hot working the applied pressure is reported to plastically deform the aluminum powder, thus breaking the oxide skin and welding the particles together. Irmann attributes the remarkable properties to the dispersion of oxide inclusions. Specifically, the product described by Irmann is one labeled SAP (Sintered Aluminum Powder) in which the initial flake powder is so fine that at least 50 pct of the flakes have one dimension of 2 microns or less. The composition of the starting aluminum shows in percent, Fe, 0.18; Si, 0.19; Zn, 0.06; Ti, 0.03; Cu, Mn, Mg, all nil; balance Al, approximately 99.5 pct. Aluminum is not the only material that has been found to have increased resistance to deformation at elevated temperatures when produced by powder metallurgy. It has been reported by Middleton, Pf eil, and Rhodes- hat platinum has a higher recrys-tallization temperature when produced by powder metallurgy and exhibits peculiar properties, many of which are similar to those of the aluminum powder products. Difficulties were encountered in explaining the reason for the strengthening in the case of platinum since the existence of the oxide is doubtful. The authors attributed the special properties to "a small amount of suitably dispersed porosity." This theory was supported by von -~eer-leder4 in the discussion to the paper, and the similarity between this method of hardening and that suggested by Rohner in his theory of age hardening was pointed out. R. de Fleury5 attempted to explain some of the properties in terms of the modulus of elasticity and elastic limit of alumina and aluminum while von Zeerleder examined the relationship between the yield strength and the reciprocal of the powder particle size. Boenisch and WiderholtQ dealt mainly with the corrosion resistance of the powder aluminum material and compared it with other aluminum alloys. The diffusion rates of other metals in SAP and pure aluminum have been compared by Seith and Lop-mann.&apos; They showed that the alloying metals diffuse particularly quickly in SAP possibly due to the very fine grain size. The properties of the Alcoa products were given by Lyle.&apos; The creep rupture properties of SAP and two of the Alcoa experimental powder products were compared by Gregory and Grant hnd it was shown that these products are vastly stronger at 900°F than are the best cast and wrought alloys at 600°F. Since the publication of these data, the authors have investigated two further aluminum powder products and it is the object of this paper to show how the high temperature creep rupture properties of the five materials vary with oxide content and with the structure as revealed by electron microscopy. Materials One of the five products, SAP, a sintered aluminum product, was supplied by the Societe Anonyme pourl Industrie de l,Aluminium, Neuhausen a/RHF, Switzerland, through Dr. R. Irmann, while the others, M276, M257, M293, and M255 were supplied by the Aluminum Company of America as experimental powder metallurgical products. M255- and M293 were made from coarse and fine atomized powders, respectively. The other materials were made from flake powders with significant differences in oxide content, the details of the type of powders used in the manufacture of these materials

Jan 1, 1955

By Earl S. Greiner, Eric R. Jette

The literalure on the binary alloys of iron and silicon has been reviewed by Stoughton and Greiner.1 Another even more extensive and detailed survey of the present knowledge has been prepared under the auspices of the Alloys of Iron Research Committee by Greiner, Marsh and Stoughton. Since the latter surrey has already been issued in its preliminary form, it will be unnecessary to review the literature in the present article. However, in this connection there should be noted the important work on the crystal structures of the iron-silicon alloys by Phragmén,2 who investigated the entire system, identified the various phases and determined the homogeneity ranges of these phases. It was evident in the surveys cited above that in the range from 0 to 15 per cent silicon, which includes the commercially most important, alloys, the results obtained by thermal analysis, microscopic examination and the determination of electrical, magnetic and mechanical properties were extremely confusing. From time to time various compounds between iron and silicon have been postulated to account for the results yielded by the classical methods, and much argument has ensued. It was presumed that if compounds occurred which are sufficiently diverse in their properties to account for the characteristics of the alloys, they should be recognizable as separate phases but satisfactory proof of this sort has not been found by thermal or microscopic methods. Contributing to the confusion is the fact that the electrical, the magnetic and some of the mechanical properties are "structure sensit&apos;ive"; i. e., they are influenced to a marked degree by the presence of minute amounts of impurities, the specific characters of these impurities, the grain size, the character of the grain boundaries, small general or local strains, etc. Thus interpretations of the discontinuities in the various property versus composition curves that identified these discontinuities with phase changes or compound formation have always been open to question.

Jan 1, 1933

By S. J. Prison, C. R. Smith

The effect of fluid injection to control water coning in oil and gas wells was investigated. Analytical and model techniques were employed. The factors investigated were the position and length of the completion interval, the point of fluid injection, the viscosity of the injected fluid and the relative thickness of the oil and water sections. The resulting influence of these factors on the net producing water-oil ratio was determined. Several important conclusions can be drawn from the study. In general, it was found that the net producing water-oil ratio can be reduced by fluid injection. The magnitude of this reduction depended on the factors listed above. An important practical consideration is that the injection fluid may be either oil or water. If the injected fluid is less dense than the connate water of the reservoir, the fluid will not be lost. This fact is reassuring when valuable oil is being injected. Efforts to suppress water production were more successful when the injection fluid was more viscous than the reservoir oil, or when a zone of reduced permeability existed in the vicinity of the point of fluid injection. Under test conditions, little benefit was derived through the use of impermeable barriers or cement "pancakes". INTRODUCTION The occurrence of water coning has been known for at least 60 years. In thin oil or gas pay sections, the presence of an oil-water or gas-water contact hinders production and often causes early abandonment of the afflicted well if a completion is even attempted. Even when relatively thick pay sections are found, the encroachment of water when a water drive is present will eventually pose serious water coning problems. This water is often corrosive, expensive to separate from the oil or gas and is costly to dispose of. The theory of water coning has been discussed by a number of authors. 1,2,3,4 Briefly, water coning to the producing interval in a well is due to pressure gradients resulting from the production of fluid from the reservoir. These pressure gradients will cause a water cone to rise toward the bottom of the producing interval if a water-oil or water-gas contact exists. The tendency of the water to cone is offset or partially offset by gravity forces since the water has a higher specific gravity than the oil. A balance then exists between two forces, gravitational forces arising from the difference in specific gravities of the oil and water, and the pressure gradients causing the flow of fluids to the wellbore. If the pressure gradient exceeds the gravitational force, water coning to the wellbore occurs and water production results. Through the years considerable thought has been given to the water coning problem. More than 50 U. S. Patents have been granted to inventors on the subject. A relatively complete literature review of the water coning problem has been made. 5 A number of these patents hold considerable promise for the solution or the partial solution of the water and/or the coning problem. Very little has been written describing field tests of techniques for the suppression of water coning. A notable exception is the paperby West. 6 He reports success in reducing gas coning by a combination of gravel packing and oil injection above the oil-producing interval. He also describes a comparable method to prevent water coning, but provides no field examples. This study experimentally and analytically verifies the benefits of oil injection as a means of partially or completely suppressing the water cone. While the gas coning problem was not treated, it is anticipated that results comparable to those obtained in water suppression could be obtained with reduced oil injection since the viscosity contrast between oil and gas exceeds that between oil and water. For the purpose of this study, the conventional potential flow theory was applied to the water-coning problem. The experimental verification centered on both a radial and a linear model. The model study permitted the investigation of complex flow configurations and the use of fluids of differing densities and viscosities. No analytic expressions are available to permit a solution of the problem as stated (see Fig. 1).

By E. V. d’Invilliers

The position of these magnetic ore-mines, with reference to the county-seat, is shown in Fig. 1. They are situated on the south margin of the Great Valley, five miles south of Lebanon, and about midway between Reading on the Schuylkill River and Harrisburg on the Susquehanna River, in three prominent, contiguous hills, standing in front of the Mesozoic red shale arid sandstone hill country of northern Lancaster and southern Lebanon counties, and overlooking the great limestone plain to the north. The three hills, named respectively Big, Middle, and Grassy Hills, and separated from each other by two branches of Furnace Creek, range in a nearly east and west direction for a distance of about one mile. Their summits are respectively 870, 715, and 700 feet above tide. The railroad line opposite the base of Middle Hill is 575 feet above tide at Cornwall and 471 feet at Lebauon. These features are all distinctly illustrated in the contour-line map accompanying this paper, but are made still more clear in the relief. map, Fig. 2, comprising, as it does, about six square miles of territory contiguous to the ore-mines. This is a photographic plate of a model made by Mr. A. E. Lehman, from surveys of my own and Mr. W. F. Shunk. The model was built in layers of cardboard, each layer representing one 10-foot contour-carve line. The scale was the same as the original map, 400 feet= 1 inch, without any vertical exaggeration. The lowest contour-line is 530 feet above ocean level; the highest, 1075 feet. The center of the model was made the focusing-point of the view, which was taken—according to scale—51/2 miles north from and 24 miles above the focusing-point, looking southward. When first mined in the last century these hills exhibited smoothlyrounded surfaces, composed of soft weathered ore of great parity, beneath which lay the great mass of hard ore, constituting the whole

Jan 1, 1886

By Warren B. Davis

Introduction If a subject this broad were to be covered in even moderate detail, it would require a set of books about the size of an encyclopedia. Since an acceptable length for this paper is a small fraction of one book, it will have to consist of a few samples of the subjects that I think are the most pertinent to World Fossil Fuel Economics. I plan to discuss the trends in world energy demand, particularly in the U. S. and Europe; the consumption patterns and cost patterns of oil, gas and coal; the prospects of synthetics; and some of the effects of government regulation of fuel economics. World Energy Demands Fig. 1 shows Free World energy consumption by principal areas for the period from 1950 to 1970 and a forecast for the period from 1970 to 1985. These figures include only the measurable forms of energy. An example of energy consumption that is not measured is the wood a peasant might cut in the forest and bum in a fireplace to heat his home. This omission probably is a very small part of the total. This forecast is not identical with that of Wayne E. Glenn (see Page 22), but the differences in total energy consumption are not significant. The U. S. consumption, which was 55 percent of the world total in 1950, had declined to 45 percent by 1970, and is expected to decline further to 38 percent by 1985. Western Europe has consumed 28 percent of the total from 1950 to 1970 and is expected to lose share slightly between 1970 and 1985. The most spectacular gainer is Japan, which increased consumption from 2.5 percent in 1950 to 7.5 percent in 1970, and is expected to reach nearly 17 percent by 1985. The over-all Free World total has grown from 62 quadrillion Btu (equivalent to 29 million B/D of crude oil) in 1950 to 151 quadrillion by 1970, an average growth rate of 4.5 percent/year. This total is expected to grow at a rate of 5 percent/year between now and 1985, reaching 315 quadrillion Btu (equivalent to nearly 150 million B/D). Fig. 2 shows which fuels supplied this energy between 1950 and 1970, and gives an estimate of how it will be supplied between 1970 and 1985.

Jan 1, 1971