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By A. K. Mukherjee, J. E. Dorn

A modified Peierls model is Presented for the rationalization of the asymmetric plastic behavior of single crystals of bcc metals. The model assumes that the asymmetry of slip arises from a tendency toward asymnetric splitting of the a/2[111] screw dislocation. The approach differs from former theories however insofar as it assumes that the splitting is so minor ttut only the core energy is modified and that no real partial dislocations exist. As a consequence, the concepts of a line energy of a partial dislocation, interaction between partial dislocations, constriction energies, and stacking fault energies are not invoked. Instead the present analysis is based on a specialization of the Peierls mechanism which assumes an asymmetric dislocation core which is modified by the effective stress and permits cross slip. The theoretical predictions on the stress-temperature -strain rate and orientation relationship agree qualitatively with the limited experimental data that are currently available. Additional experimental work over wider ranges of conditions is suggested to provide more complete evaluation of the possible validity of this theory. RECENT experimental investigations on the low-temperature thermally activated deformation of bcc metals have confirmed the existence of several unique orientation effects. These will be described with the aid of the standard stereographic projection shown in Fig. 1. If slip were determined exclusively by crystal symmetry, the deformation characteristics would be symmetrical about X; = 0 and independent of whether the specimen were subjected to a tension or a compression stress, regardless of what combinations of slip planes might be operative. Experiments, however, reveal that neither of these symmetry based predictions are valid. A schematic representation of the commonly observed asymmetry of both the yield stress and the plane of slip is shown in Fig. 2. A reversal of the direction of stressing results in an inversion of the asvmmetric behavior. 1) Asymmetry bf Yielding. A detailed investigation on the asymmetric yielding in an Fe-2.7 pct Si alloy was repoEted by Tabka, Tikeuchi, and Furubayashi,1 Similar trends have been observed by Keh and Nakada on iron,' Stein on molybdenum,3 Bowen, Christian, and Taylor4 on columbium, Sherwood, Guiu, Kim, and pratt5 on Ta, Cb, and Mo. The degree of asymmetry not only depends on the atomic number and alloying but, in all cases that have been examined, it also increases with a decrease in the test temperature. 2) Asymmetry of the Slip Plane. Asymmetric $I-~: curves of the type shown in Fig. 2 have been found for several Fe-Si alloys6-8,1 and columbium.4 There is general agre_ement that near X: = 30 deg slip occurs by the [111](211) mode so that ?1 = 30 deg. As X; decreases it appears that [111](211) to [111](101) cross slip takes place leading to slip band traces on intermediate planes. And as xi approaches 0 deg, sharp

Jan 1, 1970

By L. G. Schulz, P. Spiegler

The electrical resistivity and the temperature coefficient of resistivity were measured with a potentiometric method using pure mercury as a reference material. Measurements were made nea,v roorn temperature. A detailed study was made of Hg,TI, near its melting temperature. THE work to be described was originally undertaken to provide the necessary data for interpreting the results of some optical experiments,' but because of the growing importance of liquid metals,273 it appeared that the results of the resistivity measurements should be published separately. For convenience the alloys selected were those which are liquid at room temperature. Special consideration was given to the Hg-T1 alloy closely corresponding to Hg,Tl, because recent X-ray diffraction results of Smallman and Frost seemed to show that the solid structure may persist to some extent into the 1iquid. EXPERIMENTAL PROCEDURE A potentiometric method was employed in which the resistivity of mercury was used as a reference. The essential features of the samples are shown in Fig. 1. A capillary tube CT with a bore of approximately 1.5 mm was fitted into two end cups, T, which were made of Teflon. A pair of current electrodes CE were immersed into the excess liquid metal which partly filled the end cups. The potential electrodes PE were inserted into CT through short pieces N of a no. 18 hypodermic needle held in place with Saureisen cement SC. As shown, the lower ends of the PE7s were reduced in diameter to 0.25 mm to minimize the distortion of the liquid metal cross section. Several methods were used to insert an alloy into the sample, but the usual one with mercury alloys was to fill the sample container with a weighed quantity of pure mercury* and then add weighed the sample tube in a vacuum. Because of rapid corrosion, samples containing gallium were of necessity prepared in a vacuum. To obtain the specific resistivity of an alloy the resistance of the sample containing the alloy was measured and compared with the resistance when the container was filled with mercury. Resistances were measured in the temperature range of 20" to 60°C to obtain the temperature coefficient of resistance. The electrical measurements were made by connecting the sample in series with the standard one-ohm resistance, and the potential drop measured alternately over the sample and the standard resistance. To correct for stray thermoelectric effects provision was made for reversing the direction of the current, and the true potential drop was taken to be the average of that obtained for the two directions of current flow. Various materials were used for the electrodes, the most uniform results being obtained with nickel. EXPERIMENTAL RESULTS The numerical results are presented graphically in Figs. 2 and 3 and in tabular form in Tables I and 11. Following are remarks on results of individual alloys. 1) Hg-In—This was the first alloy studied, and

Jan 1, 1960

By Warren B. Weeks

The year 1940 saw an increase of 20 per cent in oil production over the previous year—compared with a 16 per cent increase the previous year. In all, 25,790,380 bbl. were produced, an increase of 4,414,150 bbl, over 1939 and the largest production figure for south Arkansas since 1928. The older settled production continued to decline. Magnolia accounted for most of the increase, with aid from the other recent deep fields. During the year, 169 wells were drilled, 79 fewer than in the previous year. Of 131 wells drilled in proven fields, 18 were dry. Three of the 38 wildcats were pool openers. The drilling depth record was increased from 9028 to 9550 feet. Trend of Prospecting For the first time since 1936, the search for oil in the deep Smackover limestone slackened perceptibly; g dry wildcats ended in Smackover, 2 in. the underlying Eagle Mills; 7 penetrated Paleozoic beds, while 9 ended in Hosston, 2 in Glen Rose, 2 in Paluxy and 4 in Gulf. Geology The wells listed in Table 2 either resulted in the discovery of new oil pools or, because of their depth or location, afforded impor-tant stratigraphic or structural informa-tion. Fig. I is a general columnar and stratigraphic section showing the relation-ship of the strata within the Comanche series. The nomenclature shown was ac-cepted by the Shreveport Geological Society. It was subsequently published by Imlay,l who indicated probable correlations with other areas and presented evidence for the possible Jurassic age of the under-lying Cotton Valley and Smackover formations. New Fields Pouke.—On June 10, 1940, the Louark Producing Co. completed its No. I Sturgis, sec. I, T. 17 S., R. 27 W., in central Miller County, producing between 3583 and 3607 ft. in the upper part of the Paluxy forma-tion. The well flowed I00 bbl. of 3r.4' gravity oil per day through Ns-in. tubing choke. This discovery resulted from seismograph work. Six other wells were drilled in the area, none of which found production in the original sand. One of these wells is producing from a sand 50 ft. deeper in the section. The others were abandoned. No further development is in prospect. Production is from lenticular sands of the upper Paluxy; 45,556 bbl. had been pro-duced by the end of 1940. There is structural closure against a fault to the northwest. McKanzie.—The Atlantic Refining Com-pany's No. I Bodcaw Lumber Co., sec. 29, T. 17 S., R. 23 W., eastern central La-fayette County, was completed June 8, 1940, as the eighth and farthest west of the Smackover (Reynolds o6lite) limestone pools. The well flowed 10 bbl. an hour of 58.6' gravity distillate through an 1 1/64 Ma-in. tubing choke, with a gas-oil ratio of 8400:I.

Jan 1, 1941

By Theron Wasson

The year 1942 in Michigan was devoted largely to the development of fields discovered in 1941 but was also characterized by a great increase in prospecting for new productive horizons below the Dundee limestone. Some new fields were discovered but as yet these have shown few signs of being of major importance. Michigan's total production for 1942, of 21,754,000 bbl. of oil, as reported by the U. S. Bureau of Mines, was second only to the record year of 1939 when 22,799,000 bbl. of oil were produced. All important fields were prorated throughout the year, and it is obvious that without proration a new all-time high would have been established for the state this year. From 1925 to the end of 1942, Michigan has produced annually the following amounts of oil: Year Barrels Source 1925 4,000 1926 94,000 1927 435,000 1928 592,000 1929 4,641,000 1929 Michigan Geological Survey 1930 3,928,000 3,785,000 1932 6,925,000 1933 7,942,000 1934 0,603,000 1935 15,776,000 U.S. Bur. Mines, 1937 1936 11,928,000 U.S. Bur. Mines, 1938 1937 16,628,000 U.S. Bur. Mines, 1939 1938 19,211,000 U.S. Bur. Mines, 1938 1939 22,799,000 1940 19,764,000 1941 16,361,000 1942 21,754,000 Total 183,170,000 This tabulation shows the steady growth of the industry in Michigan since the first discovery of oil in 1925. Maes A map of the oil and gas fields of Michigan in 1941, published in the report for 1942, shows the main producing areas and should be referred to if information in regard to their location is desired.* The main producing zones were shown in the columnar section in the same publication. Development in Fields Reed City Field.—During 1942 the Reed City field, which ended 1941 with 112 producing oil wells, added 70 new producers to bring the total at the end of the year to 182 wells and 4700 proven acres. A south extension of the field developed during the year was in large part responsible for the increase. Approximately 9,000,000 bbl. of oil was produced from the field during the year, bringing the total accumulated production to the end of the year to roughly 11,750,000 barrels. Headquarters Field.—The Headquarters field, which started the year with ro producing oil wells, ended the year with 41 wells aid 1240 proven acres. Approximately 2,300,000 bbl. of oil was produced in 1942. Kawkawlin Field.—Although not a 1941 discovery, the Kawkawlin field has been actively developed on the 40-acre spacing plan during the last year, 42 producers having been completed, bringing the total number of wells at the end of the year to 77. Nearly 500,000 bbl. of oil was produced during the year.

Jan 1, 1943

By G. B. Craig, G. L. Montgomery

A simple technique has been developed which reveals glide dislocations in zone-refined aluminum as etch pits. The technique has been tested quantitatively by making dislocation counts on aluminum single crystals deformed in pure bending. The method has the advantage of being insensitive to the orientation of the surface under examination. A number of etchants which will reveal dislocations in annealed aluminum have been reported.'-' These etchants apparently depend on decoration of the dislocations by an impurity (probably iron) and cannot, therefore, be used to reveal fresh glide dislocations. In addition, it is unlikely that screw dislocations will be etched because of their small attraction for impurity atoms. Amelinckx6 has reported that glide dislocations located along slip traces can be revealed by fluo-rated aqua regia. This work indicated that dislocations themselves, irrespective of decoration by impurity atoms, are responsible for the etch pits. However, as a result of additional etching experiments, Wyon and Marchin7 concluded that dislocations alone are not sufficient to explain the localization of etch pits on slip lines in aluminum using chemical etch-pitting techniques. In addition, their results show that glide dislocations are revealed only on surfaces approximately parallel to a (100) axis and that not all slip systems are attacked. These observations have been confirmed by the present authors. The technique described in this article is insensitive to the orientation of the surface, and reveals dislocations on all glide systems. Fig. 1 shows a deformed region in the neighborhood of a scratch. Dislocations can be seen along three slip traces. In the present work, single crystals of zone-refined aluminum are polished for from 2 to 5 min in a chemical polishing reagent held at 100°C, as described by Herenguel and second:' H2Sol 60 pct H3PO4 30 pct HNO3 10 pet The samples are then coated with a thin oxide film by annealing in air at 450°C for 1 hr and cooling in the furnace. After deformation, dislocation etch pits are developed by immersing the specimen in the same polishing solution which is now held at a temperature of 50°C. The formation of small hydrogen bubbles indicates that etching has occurred. The sample is immediately removed from the solution. Prolonged etching results in enlargement of the pits and, in regions of high dislocation density, the overlapping and loss of resolution of individual pits. It is the experience of the authors that contact with iron will ruinously contaminate the reagent. With careful etching, dislocations separated by half a micron can be resolved optically and the method has been shown to be sufficiently sensitive to reveal dislocations produced during the pre-easy glide region of deformation, Fig. 2. A few examples of glide-dislocation configurations, as revealed by this technique, are shown in Figs. 1 to 4.

Jan 1, 1964

By Alfred R. Powell

LATE in 1944 a group of petroleum and coal technologists was organized in Wash¬ington under the sponsorship of the Petroleum Administration for War and the U. S. Bureau of Mines. This group, known as the Technical Oil Mission, was placed under the authority of the Technical Industrial Intelligence Committee of the Joint Chiefs of Staff, which was then promoting the organization of other missions to be sent to Germany to obtain technical information regarding various industries in that country. The objective of the Technical Oil Mission was to obtain technical data on German production of synthetic oil from coal and all other commercial practices and research projects connected with the oil industry. The primary purpose was to obtain such data as were immediately essential to assist the war against Germany and Japan, with secondary emphasis on technical information that would assist American industry after the end of the war. Since oil-production facilities in Ger¬many and the occupied countries con¬trolled by Germany were the top targets for strategic bombing, the Technical Oil Mission was the first group under the Technical Industrial Intelligence Com¬mittee to enter Germany. A few members of the group flew to London in February 1945 and the majority of the remainder followed in March. In London they were joined by an equal number of British investigators and the combined, mission was then sent into Germany under the authority of the Combined Intelligence Objectives Subcommittee (CIOS). A sum¬mary of the more important information gained by this combined British and American mission is presented below. GERMAN OIL PRODUCTION The oil available to Germany, both natural and synthetic, and including pro¬duction from occupied countries, reached a peak in late 1943 and early 1944. Pro¬duction at this time was at the rate of 1,200,000 metric tons per month, equiva¬lent to i00,000,000 bbl. per year, or about 7 per cent of the wartime production in the United States. Of this production, 50 per cent was crude oil from Romania and Hungary, 12 per cent was crude oil from Germany itself, including Austria, 9 per cent com¬prised coal-carbonization products, that is, tar and light oil, and only the remaining 29 per cent was synthetic liquid fuel made from coal or tar. Synthetic liquid fuel made in Germany was equivalent therefore to less than 2 per cent of war¬time production of crude oil in the United States. The success of the strategic bombing campaign against German oil-production facilities is demonstrated by the fact that by September 1944 the Ploesti fields of Romania and much of the syn¬thetic oil production had been eliminated, so that the amount of oil available to the German war machine was only 25 per cent of the peak quantity mentioned above. By early 1945, when the combined British and American oil mission was entering

Jan 1, 1946

By Theron Wasson

The year 1942 in Michigan was devoted largely to the development of fields discovered in 1941 but was also characterized by a great increase in prospecting for new productive horizons below the Dundee limestone. Some new fields were discovered but as yet these have shown few signs of being of major importance. Michigan's total production for 1942, of 21,754,000 bbl. of oil, as reported by the U. S. Bureau of Mines, was second only to the record year of 1939 when 22,799,000 bbl. of oil were produced. All important fields were prorated throughout the year, and it is obvious that without proration a new all-time high would have been established for the state this year. From 1925 to the end of 1942, Michigan has produced annually the following amounts of oil: Year Barrels Source 1925 4,000 1926 94,000 1927 435,000 1928 592,000 1929 4,641,000 1929 Michigan Geological Survey 1930 3,928,000 3,785,000 1932 6,925,000 1933 7,942,000 1934 0,603,000 1935 15,776,000 U.S. Bur. Mines, 1937 1936 11,928,000 U.S. Bur. Mines, 1938 1937 16,628,000 U.S. Bur. Mines, 1939 1938 19,211,000 U.S. Bur. Mines, 1938 1939 22,799,000 1940 19,764,000 1941 16,361,000 1942 21,754,000 Total 183,170,000 This tabulation shows the steady growth of the industry in Michigan since the first discovery of oil in 1925. Maes A map of the oil and gas fields of Michigan in 1941, published in the report for 1942, shows the main producing areas and should be referred to if information in regard to their location is desired.* The main producing zones were shown in the columnar section in the same publication. Development in Fields Reed City Field.—During 1942 the Reed City field, which ended 1941 with 112 producing oil wells, added 70 new producers to bring the total at the end of the year to 182 wells and 4700 proven acres. A south extension of the field developed during the year was in large part responsible for the increase. Approximately 9,000,000 bbl. of oil was produced from the field during the year, bringing the total accumulated production to the end of the year to roughly 11,750,000 barrels. Headquarters Field.—The Headquarters field, which started the year with ro producing oil wells, ended the year with 41 wells aid 1240 proven acres. Approximately 2,300,000 bbl. of oil was produced in 1942. Kawkawlin Field.—Although not a 1941 discovery, the Kawkawlin field has been actively developed on the 40-acre spacing plan during the last year, 42 producers having been completed, bringing the total number of wells at the end of the year to 77. Nearly 500,000 bbl. of oil was produced during the year.

Jan 1, 1943

By J. H. Wernick, S. Geller

A number of new AB, compounds, in which A is a rare earth or yttrium atom and B is Al, Mn, Fe, Co, or Ni, having the cubic MgCu, structure (Laves phase) are reported. In most of the compounds, the interatomic distances are normal; the lanthanide contraction is observed. However, in the compounds CeB2, B = Fe, Co, Ni, Ce appears to have a valence substantially greater than three; in CeAl2, Ce appears to be trivalent. These results are interpreted as vesulting from an energetically more favorable situation for the 4f electron of Ce to be lost to the 3d band of Fe, Co, nnd Ni. Evidence for the existence of homogeneitj! ranges in these compounds is presented. THE purpose of this paper is to report on the crys-tallographic investigations of a large number of new compounds, Table I, with the MgCuz structure (cubic Laves phase). It is a part of a continuing study of the magnetic properties and structures of binary systems involving the rare earths. In a previous paper' some of the magnetic properties of such systems were reported briefly. We have also reported2 a number of compounds of the CusCa type. The compounds were prepared by induction melting in Argon atmosphere of mixtures of stoichiomet-ric amounts of the constituent elements.* For most of the compounds fused alumina or silica crucibles were used as the containing vessel; graphite crucibles were used to prepare CeA12, NdAl2 and TbA12. X-ray powder photographs were taken with CrKa radiation and the use of Straumanis-type Norelco cameras of 114.6 mm diam. The compounds AB2 belong to space group Fd3m-Ol with 8A in a): (000; 01/2 '/2;3) + 000-; b % XA and 16B in dl: (000; oVa %; 3) + 5/87; % %; 7e % Vs\£>. Because the intensities of the reflections on the powder photographs of the different compounds are similar, relative intensities were computed only for DyMnz for CrKa radiation, Table 11. In the calculation of intensities, the Thomas and umeda3 atomic scattering factors, corrected for dispersion,4 were used. The agreement between observed and calculated intensities leaves little doubt that DyMnz has the MgCuz structure. Crystallographic data for the ABz compounds are given in Table JII. Twelve of these compounds have been reported by other authors. A comparison of the published results with our work is given in Table W.* ers of elements of lower purity, to peritectic reactions in some cases, and to the presence of homogeneity ranges in these alloys, so that melting losses would still result in single phase alloys. The possibility of existence of homogeneity ranges in these compounds was investigated systematically only for GdMnz. At room temperature, the solid solution range is between

Jan 1, 1961

By C. W. Donnelly, Louise B. Freeman, Coleman D. Hunter

It is with pride that the authors of this paper report. that during 1944 the production of petroleum in Kentucky passed its all-time peak, 9,496,985 bbl. being contributed. The delivery of natural gas, especially from eastern Kentucky, was maintained and possibly exceeded the highest deliveries of the past. To raise the production of oil and gas was not easy with inferior and worn-out equipment and the shortage of skilled labor. Reminiscent of the early days of the industry in the state, particularly in the hills of Elliott County, where mud roads often have gradients of 45º, was the replacement of worn-out trucks and tractors by oxen. Of the total 9,496,985 bbl., 17 per cent was contributed by the part of Kentucky that is east of the Cincinnati arch, as compared with the total of 7,010,776 bbl. contributed in 1943, of which 25 per cent was contributed by eastern Kentucky. This discrepancy is due to the discovery of more new fields in western Kentucky rather than to a decrease in production in the eastern fields, where the average has been maintained by reconditioning and secondary recovery of old fields and further development of new pools reported for the first time in 1943. In all, 1103 wells were known to have been drilled in the state during 1944, of which 659 were drilled in western Kentucky and 444 in eastern Kentucky. The exact number of wells drilled for any year is never known, as drilling permits are not required except 'when it is planned to drill through a workable coal seam. Of the total number of wells drilled, 459 were oil wells, 229 gas wells and 415 dry holes. The monthly production was as follows: January........................... 659,496 February.......................... 658,606 March...................... ...... 711,619 April............................. 649,926 May............................... 754,892 June.............................. 730,369 July.............................. 761,762 August............................ 878,053 September...................... 863,150 October........................... 968,732 November........................ 961,999 December........................ . 898,636 Western Kentucky In western Kentucky 352 wells were completed as oil wells with a total initial production of 47,922 bbl. of oil, the average being 136 bbl. per well. Two wells produced gas, the total initial production being 1,594,000 cu, ft. One hundred and eighteon wildcat wells were drilled, of which 107 were dry holes and 11 were oil wells. Three of the latter proved to be the discovery wells of commercial pools. Twelve new pools were discovered during 1944, none of major importance, as indicated in Table 2. The Utley pool, due to a stratigraphic trap on the flank of a closed structure, found oil in the Mcclosky at 2565 ft. in the discovery well, with initial productioil of 1000 bbl. The average daily production is now 227 bbl. from seven wells. The East Poole field, with the discovery well in the Tar Springs sandstone at 1811

Jan 1, 1945

By Warren B. Weeks

The year 1940 saw an increase of 20 per cent in oil production over the previous year—compared with a 16 per cent increase the previous year. In all, 25,790,380 bbl. were produced, an increase of 4,414,150 bbl, over 1939 and the largest production figure for south Arkansas since 1928. The older settled production continued to decline. Magnolia accounted for most of the increase, with aid from the other recent deep fields. During the year, 169 wells were drilled, 79 fewer than in the previous year. Of 131 wells drilled in proven fields, 18 were dry. Three of the 38 wildcats were pool openers. The drilling depth record was increased from 9028 to 9550 feet. Trend of Prospecting For the first time since 1936, the search for oil in the deep Smackover limestone slackened perceptibly; g dry wildcats ended in Smackover, 2 in. the underlying Eagle Mills; 7 penetrated Paleozoic beds, while 9 ended in Hosston, 2 in Glen Rose, 2 in Paluxy and 4 in Gulf. Geology The wells listed in Table 2 either resulted in the discovery of new oil pools or, because of their depth or location, afforded impor-tant stratigraphic or structural informa-tion. Fig. I is a general columnar and stratigraphic section showing the relation-ship of the strata within the Comanche series. The nomenclature shown was ac-cepted by the Shreveport Geological Society. It was subsequently published by Imlay,l who indicated probable correlations with other areas and presented evidence for the possible Jurassic age of the under-lying Cotton Valley and Smackover formations. New Fields Pouke.—On June 10, 1940, the Louark Producing Co. completed its No. I Sturgis, sec. I, T. 17 S., R. 27 W., in central Miller County, producing between 3583 and 3607 ft. in the upper part of the Paluxy forma-tion. The well flowed I00 bbl. of 3r.4' gravity oil per day through Ns-in. tubing choke. This discovery resulted from seismograph work. Six other wells were drilled in the area, none of which found production in the original sand. One of these wells is producing from a sand 50 ft. deeper in the section. The others were abandoned. No further development is in prospect. Production is from lenticular sands of the upper Paluxy; 45,556 bbl. had been pro-duced by the end of 1940. There is structural closure against a fault to the northwest. McKanzie.—The Atlantic Refining Com-pany's No. I Bodcaw Lumber Co., sec. 29, T. 17 S., R. 23 W., eastern central La-fayette County, was completed June 8, 1940, as the eighth and farthest west of the Smackover (Reynolds o6lite) limestone pools. The well flowed 10 bbl. an hour of 58.6' gravity distillate through an 1 1/64 Ma-in. tubing choke, with a gas-oil ratio of 8400:I.

Jan 1, 1941

By Louis A. Panek

THE purpose of this paper is to present a method of designing safe and economical arch structures that are to be constructed of concrete or directly of original earth materials. The experimental data used to illustrate the design method are taken from Bucky and Fentress,1,2 and the application of the ideas presented by them is extended by obtaining an additional set of curves from which arch structures may be designed. This design method is based upon the following principles of similitude: A scalar model made of the same material as that of the full sized structure will behave similarly to its prototype if the density of the model is increased in the same proportion as its linear scale is decreased. Let R represent the scale or model ratio, namely, the ratio of a prototype linear dimension to the corresponding model linear dimension. The effect of increased density may be obtained by rotating the model in a centrifuge at a speed such that the centrifugal field exerts on the model an accelerative force R times the accelerative force of gravity. Under these conditions; (I) model unit stresses are equal to corresponding prototype unit stresses, (2) the ratio of the prototype deformation at a given point to the model deformation at a similar point is equal to the scale ratio, R, and (3) the model and the prototype will behave similarly within and beyond the elastic limits of strain. According to the above relations, such models can be used to solve the following problems: I. The dimensions of the most economical safe arch structure for a given load. 2. The maximum safe roof span underground for given geologic conditions. The procedure is described briefly as follows. Tests are made by rotating in a centrifuge a number of models that repIesent a variety of prototype loads and dimensions. From the experimental data, curves are plotted to show the relations between these loads and dimensions. The curves are used to solve directly the problems stated above. Structural design is based upon the working (safe) stress of the material of construction, which is established by applying a factor of safety to the experimentally determined ultimate strength of the material. In conformity with this principle, each model is gradually loaded until failure occurs. A safety factor is then applied to the results. If a safety factor of 4 is used, a given model at failure represents a safe prototype, the linear dimensions of which are equal to one-fourth the model ratio at failure times the corresponding model dimensions. The safe model ratio is computed from the following formula: [Safe R = (rl 47r2n2r _ 7r2n2r~r~ \4/ gg in which: n = centrifuge revolutions per second at model failure; r = radius of rotation of the model in feet; g = 32.2 ft/sect.]

Jan 1, 1947

US 4,137,751-Aerial geophysical exploration for ore deposits by collecting and analyzing atmospheric particulates The aircraft has an Inlet duct extending outward and including a "shave-off" duct, a cyclone separator located inside the cabin which is coupled to the inlet duct, a clean air exhaust duct, and a receiver for the collected particles incoming air is divided into two fractions. The fraction taken by the "shave-off" duct and containing the bulk of the particles is routed to the cyclone Particulates are gathered on a collector tape for subsequent analysis and correlation with the areas covered J. R Rhodes, R D. Sieberg, M. C Taylor, J. C Westkaemper, and R C. Young, assigned to Columbia Scientific Industries, Inc Feb. 6, 1979 7 pp. (73-28) Filed- 2-28-75 (554,114) Same British 1,446,760, dated Aug. 18, 1976. US 4,156,138-Exploration for subsurface deposits of uranium ore Pairs of dosimeters are placed underground in a grid pattern Each dosimeter contains a phosphor which IS capable of storing the energy of alpha particles. One dosimeter is heavily shielded from alpha particles, while the other in the pair is thinly shielded to exclude dust After a period underground the dosimeters are heated to release the stored energy as light. The amount of light produced from the heavily shielded dosimeter is subtracted from the amount of light produced from the thinly shielded dosimeter to give an indication of the location and quantity of uranium underground This patent is a division of US Patent No 4,053,772, dated Oct 11, 1977 P E Felice, assigned to Westinghouse Electric Corp May 22, 1979 5 pp (250-253) Filed. 8-12-77 (824,203) US 4,180,727-Method for measuring the gamma-gamma density of uranium ore in the vicinity of a borehole A first gamma-ray detector receives only natural gamma rays from the borehole, while a second receives both natural gamma rays and scattered uranium-source gamma rays The value of the uranium-source gamma rays is calculated. W W Givens, assigned to Mob11 011 Corp Dec 25, 1979 6 pp (250- 264) Filed 10-20-77 (843,909) US 4,180,72&A neutron activation probe for determining the location and grade of uranium ore, especially where thorium or other fissionable isotopes are present, includes a pulsed neutron source in series with a plurality of delayed neutron reactors for measuring radioactivity in a well bore- hole together with a Nal(T1) counter for measuring the high energy 2 62 MeV gamma line from thorium The signal from the Nal(T1) counter IS subtracted from the signal from the delayed source detectors to ascertain the amount of uranium present in the ore body N. P Goldstein and R C Smith, assigned to Westinghouse Electric Corp Dec 25,1979 6 pp (250-264) Filed. 4-1 1-78 (895,323)

Jan 1, 1980

By Jr. D. C. Williams, D. V. Carter

The four new oil-field discoveries made in the East and East Central Texas districts during 1941 were the East Long Lake field, Anderson County; Pickering field, Shelby County; Pleasant Grove field, Rusk County, and Tri-Cities field, Henderson County. The discovery of oil production in the Pettit lime of the Lower Glen Rose was made in the Groesbeck (Barron) field in Limestone County and the Willow Springs field in Gregg County. Important extensions were made to the Pittsburg field, in Camp County, the Chapel Hill field, in Smith County, and the Hawkins field, in Wood County. The Hawkins field was extended sufficiently to more than double the number of proved surface acres. As usual the East Texas field led the district in the number of completions for the year. The second most active field during the year was the Hawkins field, with 250 new wells completed. The third most active was the Long Lake field, in which 50 wells were completed. Approximately 964 wells were completed in the district during 1941. Production and Probation The district is credited with having produced 163,566,695 bbl. of oil and distillate during the year. This represents a decrease of 4 per cent from the 170,424,685 bbl. of oil and distillate produced during the preceding year. The production of 130,378,620 bbl. of oil and distillate from the East Texas field represents 79.7 per cent of the total production of the district; that is, 6.3 per cent less than the production for the year 1940, The district had an estimated basic daily allowable of 614,982 bbl. of oil on Dec. 31. Approximately 33 per cent of the state's annual production was produced in the district, compared with 34.9 per cent for 1940. Since the majority of the fields in this district are subject to proration, any change in the annual production is attributable largely to changes in proration schedules and number of shutdown days. Fields subject to shutdown days were closed in for 113 days during the year, with the exception of the East Texas field, which was shut down 111 days. An order was promulgated by the Oil and Gas Division of the Texas Railroad Commission for encouraging the disposal of salt water and reservoir-pressure maintenance in the East Texas field. Discoveries Tex Harvey Oil Company'sNo. I S. E. J. Cartmel was completed as the discovery well for the East Long Lake field, Anderson County. Production was found in the Woodbine sand, the horizon from which the Long Lake field produces. The Pickering field, Shelby County, secures its production from the Nacatoch sand, found at an approximate depth of 1510 ft., in A. E. McKiernan's No. I, Pickering Lumbering Co. This field is in an area near the state line in which a number of relatively unimportant and

Jan 1, 1942

By H. A. Doerner, F. D. DeVaney, J.B. Clemmer

Production of magnesium metal in the United States during the past decade has increased from less than 600,000 lb. in 1928 to more than 4,800,000 lb. in 1938.1 The growing industry has stimulated interest in methods of production and in sources of raw material. All of the present domestic production is from brines. However, the availability of large tonnages of magnesite in the state of Washington, together with the possibility of cheap power, have created interest in the utilization of magnesite for the production of magnesium metal as well as for other purposes. Magnesite, the carbonate of magnesium (MgCO3), usually is associated with limestone (CaC03) and dolomite (MgCO3. CaC03). It occurs in crystalline and microcrystalline (sometimes termed amorphous) forms.2 The more common crystalline mineral is found in various shades of white, gray, yellow and brown, the colors being due to impurities, chiefly iron. Magnesite has a hardness of 3.5 to 4.5 and a specific gravity of 3.0 to 3.1. It forms rhombohedra1 crystals in the hexagonal system, having a vitreous, pearly luster. The quarries and mines of the Northwest Magnesite Co. near Chewelah, Wash., are large producers of magnesite for refractories. The deposits are extensive, some veins being hundreds of feet wide. The boundaries of the veins are indefinite, and the magnesite is interfingered with dolomite. Calcite, talc, serpentine, quartz and shale are disseminated through the deposits. The quality of the ore cannot be determined by appearance or by simple tests; chemical analysis is required. These features make it difficult to determine the boundaries or total quantity of workable ore.3 Only the higher-grade ores are mined, and a considerable proportion of the magnesite content is discarded by hand-sorting and log-washing methods. After calcining, the sorted product meets the specifications for usual refractory material, as it contains approximately 81 per cent MgO, 7 per cent SiO2, 6 per cent CaO and 6 per cent Fe203 + A1203. A sample of the reject material had the following analysis after calcining: 65.4 per cent MgO, 6.3 CaO, 21.1 SiO2 and 6.5 R2O3. The percentage reported as R2O3 includes compounds whose chlorides are acid-soluble but give precipitates in ammoniacal solution that are ignited and weighed. The more common constituents are Fe2O3, A1203 and TiO2. The sorted magnesite product is not the best grade. even for refractory purposes, and leaves much to be desired for a reduction process. The rejected material contains a large proportion of magnesite. It is apparent that an effective concentration method would yield a higher recovery and a better product. In general, the refractory grade is not suitably pure for other uses. Recent developments in the production of

Jan 1, 1943

By J. M. Smith, D. Kunii, P. Adivarahan

Effective thermal conductivities were measured for seven samples of porous rocks through which gases or aqueous salt solution were flowing, parallel and countercurrent to the flow of heat. The results are analyzed in terms of the contributions of the solid and fluid phases to the total energy transfer. The solid contribution for the sandstone samples studied was found to be a Junction of the porosity and an effective thermal conductivity for the solid phase. The fluid contribution was a function of the Peclet number. Based upon the equations presented, the effective conductivity of the system can be estimated from the properties of the fluid, the flow conditions, and the porosity and pore-size distribution of the rock. INTRODUCTION Heat-transfer characteristics of porous media containing fluids are needed for the design and evaluation of thermal methods of petroleum production. The study reported here considers the problem of countercurrent flow of fluid and heat in sandstone rocks, and is a continuation of previous studies concerned with parallel and radial flow of energy and fluid in both rocks517 and beds of fine particles.6,10 In addition to these earlier works, Asaad,1 Kimura,4 Preston,8 Zierfuss and vlietll and waddams9 have reported effective conductivities for systems filled with stagnant fluids. There appears to be no published data on rocks through which fluids are flowing. The purpose of this study was to present such information and, particularly, to investigate the effects of properties of the rock and the flow rate on the results. The rock samples were naturally occurring sandstones from different locations and were similar to petroleum-bearing formations. The properties of the seven samples showing the range in porosities and permeabilities are given in Table 1. The mean pore sizes were calculated from mercury penetration data by averaging the radius with respect to pore volume. The details of this method and comparison with other procedures for estimating 7 are given elsewhere. Four fluids, nitrogen, carbon dioxide, helium and 10 weight per cent sodium-chloride solution were used with each sample. For Bartlesville sandstone, BA-5, runs were made at mean pressures from 15 to 250 psig using nitrogen. The other measurements were carried out at a mean pressure of 100 psig. The maximum temperature range eacountered was 70° to 300°F. The flow rate of fluid ranged from about 1.0 to 130 Ib/(hr)(sq ft), and this corresponded to a modified Reynolds-number range of 5 x 10-4 to 1.0. The variation in Prandtl number was 0.70 to 4.1. EXPERIMENTAL WORK The equipment consisted of apparatus to supply a constant flow of gas, or salt solution, at constant pressure to the bottom of a vertical test section, and metering and flow-regulation apparatus after the test section. The flow of salt solution was

By W. D. Potter, E. T. Peters

Single-crystal films of boron have been prepared by thermal reduction of purified BCl3 with subsequent deposition of boron onto oriented silicon substrates. The structural properties of films prepared under various experimental conditions have been determined by light microscopy and "grazing-" angle electron-diffraction analysis. An orientation relationship is proposed for silicon and a-rhombo-heclral boron which can be described as: (111)Si (112)B; [110]Si [110]B ElEMENTAL boron is known to have a high energy gap* and consequently has potential value as a high- *Energy gaps of 1.35 to 1.55 ev1-3 and 2.0 ev4 are reported for ß-rhombohedra1 and a-rhombohedra1 boron, respectively. temperature semiconductor.5 Exploitation of this property, however, has been hampered by the unavailability of pure, single-crystal boron. Two recent symposia6,7 have treated the subjects of purification, crystallization, crystal structure, and properties of boron and provide a foundation for further investigation in these areas. The structure, lattice constants, and observed ranges of stability for four reported polymorphs of boron8°12 are listed in Table I. The rhombohedral structures are generally accepted as true polymorphs whereas the tetragonal structures are believed to be transient. Most currently available single crystals of boron are grown by Czochralski and floating-zone methods. Unfortunately, these crystals generally contain numerous defects and are highly strained as a result of the polymorphic transformations and thermal contractions which accompany cooling. Recently, Armington, Potter, and Tanner13 have reported the formation of single-crystal films of boron on silicon single-crystal substrates through thermal reduction of BC13 by hydrogen. Boron E. T. PETERS, Junior Member AIME, is Senior Scientist, ManLabs, Inc., Cambridge, Mass., and W. D. POTTER is Research Chemist, Air Force Cambridge Research Loboratories, L. G. Hanscom Field, Bedford, Mass. formed at temperatures near 1000°C was identified as the a-rhombohedra1 form, consistent with expectation. The present paper describes a continuation of this work with specific reference to characterization of the structural features of the deposited boron films. The ultimate goal of this program is to produce large-area single-crystal films of a-rhombohedra1 boron to be used for electrical and optical studies by other workers. PREPARATION OF BORON FILMS The experimental procedure of preparing thin films is similar to that described by Theuerer14 for the epitaxial growth of silicon by thermal reduction of SiC14 and has already been described as applied to the preparation of boron thin films.13 Briefly, a mixture of BCl3 vapor and dry hydrogen is passed over a heated silicon substrate. Thermal reduction of the BC13 allows deposition of boron on the substrate. The substrates were {111}-oriented, single-crystal silicon. Square specimens 0.63 cm on an edge by 0.1 to 3.0 mm thickness were prepared by

Jan 1, 1965

By J. B. Clemmer, F. D. DeVaney, H. A. Doerner

Production of magnesium metal in the United States during the past decade has increased from less than 600,000 lb. in 1928 to more than 4,800,000 lb. in 1938.1 The growing industry has stimulated interest in methods of production and in sources of raw material. All of the present domestic production is from brines. However, the availability of large tonnages of magnesite in the state of Washington, together with the possibility of cheap power, have created interest in the utilization of magnesite for the production of magnesium metal as well as for other purposes. Magnesite, the carbonate of magnesium (MgCO3), usually is associated with limestone (CaC03) and dolomite (MgCO3. CaC03). It occurs in crystalline and microcrystalline (sometimes termed amorphous) forms.2 The more common crystalline mineral is found in various shades of white, gray, yellow and brown, the colors being due to impurities, chiefly iron. Magnesite has a hardness of 3.5 to 4.5 and a specific gravity of 3.0 to 3.1. It forms rhombohedra1 crystals in the hexagonal system, having a vitreous, pearly luster. The quarries and mines of the Northwest Magnesite Co. near Chewelah, Wash., are large producers of magnesite for refractories. The deposits are extensive, some veins being hundreds of feet wide. The boundaries of the veins are indefinite, and the magnesite is interfingered with dolomite. Calcite, talc, serpentine, quartz and shale are disseminated through the deposits. The quality of the ore cannot be determined by appearance or by simple tests; chemical analysis is required. These features make it difficult to determine the boundaries or total quantity of workable ore.3 Only the higher-grade ores are mined, and a considerable proportion of the magnesite content is discarded by hand-sorting and log-washing methods. After calcining, the sorted product meets the specifications for usual refractory material, as it contains approximately 81 per cent MgO, 7 per cent SiO2, 6 per cent CaO and 6 per cent Fe203 + A1203. A sample of the reject material had the following analysis after calcining: 65.4 per cent MgO, 6.3 CaO, 21.1 SiO2 and 6.5 R2O3. The percentage reported as R2O3 includes compounds whose chlorides are acid-soluble but give precipitates in ammoniacal solution that are ignited and weighed. The more common constituents are Fe2O3, A1203 and TiO2. The sorted magnesite product is not the best grade. even for refractory purposes, and leaves much to be desired for a reduction process. The rejected material contains a large proportion of magnesite. It is apparent that an effective concentration method would yield a higher recovery and a better product. In general, the refractory grade is not suitably pure for other uses. Recent developments in the production of

Jan 1, 1943

By Jr. D. C. Williams, D. V. Carter

The four new oil-field discoveries made in the East and East Central Texas districts during 1941 were the East Long Lake field, Anderson County; Pickering field, Shelby County; Pleasant Grove field, Rusk County, and Tri-Cities field, Henderson County. The discovery of oil production in the Pettit lime of the Lower Glen Rose was made in the Groesbeck (Barron) field in Limestone County and the Willow Springs field in Gregg County. Important extensions were made to the Pittsburg field, in Camp County, the Chapel Hill field, in Smith County, and the Hawkins field, in Wood County. The Hawkins field was extended sufficiently to more than double the number of proved surface acres. As usual the East Texas field led the district in the number of completions for the year. The second most active field during the year was the Hawkins field, with 250 new wells completed. The third most active was the Long Lake field, in which 50 wells were completed. Approximately 964 wells were completed in the district during 1941. Production and Probation The district is credited with having produced 163,566,695 bbl. of oil and distillate during the year. This represents a decrease of 4 per cent from the 170,424,685 bbl. of oil and distillate produced during the preceding year. The production of 130,378,620 bbl. of oil and distillate from the East Texas field represents 79.7 per cent of the total production of the district; that is, 6.3 per cent less than the production for the year 1940, The district had an estimated basic daily allowable of 614,982 bbl. of oil on Dec. 31. Approximately 33 per cent of the state's annual production was produced in the district, compared with 34.9 per cent for 1940. Since the majority of the fields in this district are subject to proration, any change in the annual production is attributable largely to changes in proration schedules and number of shutdown days. Fields subject to shutdown days were closed in for 113 days during the year, with the exception of the East Texas field, which was shut down 111 days. An order was promulgated by the Oil and Gas Division of the Texas Railroad Commission for encouraging the disposal of salt water and reservoir-pressure maintenance in the East Texas field. Discoveries Tex Harvey Oil Company'sNo. I S. E. J. Cartmel was completed as the discovery well for the East Long Lake field, Anderson County. Production was found in the Woodbine sand, the horizon from which the Long Lake field produces. The Pickering field, Shelby County, secures its production from the Nacatoch sand, found at an approximate depth of 1510 ft., in A. E. McKiernan's No. I, Pickering Lumbering Co. This field is in an area near the state line in which a number of relatively unimportant and

Jan 1, 1942

By P. B. Crawford, W. L. Huskey

A study has been made to determine the effects of random vertical fractures existing in a reservoir matrix on the effective matrix properties and producing characteristics of a well. The study indicated that short vertical fractures may distort the isopotentials by 1 percent in the vicinity of the fracture. A correlation was developed which showed the effect of fracture density on the producing capacity of a well. The correlation indicated that fracture shape had little effect on producing capacity, but that total fracture length was closely correlated with the producing capacity. Effective values of reservoir permeability were found to correlate closely with fracture density when measured parallel to the direction of flow. INTRODUCTION In reviewing the petroleum literature, it is found that in most analytical solutions of hydrocarbon reservoir behavior the assumption is made that the rock is uniform throughout although core analysis and well logging surveys indicate that substantially all reservoirs are heterogeneous and some are fractured. Only in recent years have investigators studied the effects of reservoir hetrogeneity. Russell1 discussed the effect of fractures in reservoirs. The literature indicates that fractures greatly affect the exploitation of man reservoirs. This is described by Elkins and Skov2 and Little-field et al. 3 Several types of reservoir heterogeneity have been studied by unsteady-state methods. In 1959, Landrum et al. 4 showed that transient phenomena in hydrocarbon reservoirs could be studied by thermal models. pickering5 studied the flow of heat in stratified linear reservoirs consisting of plates of different metals separated by sheets of rubber which were suddenly exposed to a low-temperature source at one end. Cotman6 studied both laterally and vertically heterogeneous thermal model reservoirs with special reference to cross flow. Another type of reservoir heterogeneity involves the presence of highly permeable, circular lenses around or near the wellbore which was studied by Miesch7 using a thermal and a steady-state model. Many studies have been made of the effects of induced hydraulic fractures on well performance. 8-10 Work regarding vertical fractures that exist initially in the reservoir was reported by Givens, et al.11 Since there appears to be little published work on the importance and influence on reservoir performance of fractures that exist out in the rock matrix, this study was conducted to determine the effects of vertical fractures on pressure distribution, producing capacity and the effective permeability of the reservoir rock. The analogy between the flow of electrical current through a conducting body and the flow of fluid in a porous medium provides a convenient method of studying various aspects of petroleum reservoirs. For electrical radial steady-state flow,12 For steady-state fluid flow, With the above analogy, it is only necessary to establish the ratio of the values of the electrical units in terms of the corresponding flow units to make the analogy quantitative. The ratios are shown below.

By Junius D. Edwards

WHEN Charles Martin Hall invented the electrolytic process for the production of aluminum, one basic requirement was a supply of pure alumina. Now, more than 50 years later, the same requirement still holds, and there are no technical straws in the wind to indicate that this situation is likely to change. Long ago, Aluminum Company of America took a number of steps to see that this country should not face shortages of alumina and aluminum in time of emergency. As one step to this end, the Company developed and used a supply of bauxite in South America in order to conserve dwindling Arkansas reserves. Another, and more a program than a step, was to investigate every type of process that might bear the possibility of utilizing the low-grade ores of aluminum that are more plentiful than bauxite. It is a long story, but the investigation included electric-furnace processes, acid extraction processes and alkaline extraction processes, with or without preliminary furnace and sinter treatments. Some of the processes developed were operated in commercial production. This work has been continuous since the first World War. The turn of the wheel came sooner than was expected when, in 1942, bauxite shipments through the Caribbean became uncertain and hazardous through the operation of submarines. The tremendous requirements of aluminum for the war effort were consuming high-grade bauxite at an alarming rate and a national search for substitutes began. High-grade bauxites, for technical and economic reasons, have been defined as those containing about 7 per cent or less of silica. While bauxite of this grade was limited in amount in the United States, there was in sight a substantially greater volume of low-grade, high-silica bauxite not amenable to economic treatment by the Bayer process, but richer in alumina than the clays or other available low-grade ores. It was at this point, and after several years of intensive research on this particular phase of the problem, that Aluminum Research Laboratories brought to completion the invention of one of its research staff, which made practical the utilization of large reserves of low-grade bauxite in America. BAYER PROCESS The Bayer process has been almost universally used for the 'production of alumina from bauxite. This process, in outline, comprises the digestion of finely ground bauxite in a solution of caustic soda (NaOH) under pressure and at an elevated temperature. Alumina in the bauxite goes into solution as sodium aluminate and the impurities-oxides of iron, titanium and silicon-remain undissolved. The undissolved residue, known as "red mud," from its color, is separated and run to waste. Aluminum hydrate (A1202.3H20) is precipitated from the solution of sodium aluminate, and the liquor containing the caustic soda and some alumina is returned to the process for digesting more bauxite. The aluminum hydrate, after washing, is calcined at a high temperature to produce

Jan 1, 1945