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By A. J. Opinsky

MANY investigators, in their discussions, have reasoned that the ductile-brittle transition in iron could be explained by the intrusion of cleavage into the normal slip process. The purpose of this note is to apply the laws of critical normal stress for cleavage and critical shear stress for slip to explain the orientation and temperature dependence of the ductile-brittle transition in body-centered cubic metals. It will be found that within a certain temperature range, single crystals tested in tension will cleave or slip, depending on their orientation. Some data recently appearing in the literature will be analyzed from this standpoint. For a single crystal with [uvw] parallel to the tensile axis, the resolved shear stress on the slip

Jan 1, 1954

By M. E. Wadsworth

"For his creative efforts in explaining the electrochemistry of sulfide mineral leaching systems." Leaching reactions that occur during the dissolution of selected base metal sulfides and metals are considered in terms of surface reactions and the influence of intermediate or final products formed. These products may be solid layers, requiring solid phase diffusion for the reaction to proceed, or ions in solution that can influence the kinetics by controlling the mixed potential of the solid. Three general types of reactions are proposed to explain observed rates of reaction. Examples are presented for non-oxidative and oxidative leaching of galena (PbS), anodic dissolution and oxidative leaching of molybdenite (MoS2) and cyanidation of silver and gold.

Jan 1, 1986

By T. O. Meyer, J. R. McVey

A 10-channel automatic data acquisition system has been assembled for underground use with the Bureau's "Tunnel Stress Relaxation Gage". The automated system was needed to improve data collection by providing a rapid, long-term printout of measurement data in tunnel stress relaxation experiments. Special unit assembling and packaging of all measurement equipment, to be used in typically hostile mine environments, is the subject of this report. Even though automatic data acquisition systems have been in use for years, none have been developed with the accuracy herein described for use in such an environment. The object of this report is to inform researchers of a workable, proven, dependable underground data acquisition system. We have found that giving attention to these packaging details many times spells the differences between success and failure of underground tests.

Jan 8, 1973

By V. R. Garfias, R. V. Whetsel, J. W. Ristori

World consumption of petroleum and related fuels for civil purposes in 1939 was close to 2,024,000,000 bbl., or approximately 110,000,000 bbl. more than in 1938, the United States accounting for 96,000,000 bbl. of the increased amount. With the annexation of Czechoslovakia and part of Poland, civil consurnption in Germany during 1939, notwithstanding sevre rationing in the last four months of the year, was 54,000,000 bbl., or only 1,600,000 bbl. less than in 1938, and domestic production of pctroleum and related fuels was some 34,000,000 bbl. short of civil consumption. The mounting petroleum requirements of the military forces of greater Germany are, of course, not included in these figures of civil consumption. To supply this deficiency Germany now must rely almost exclusively on the Rumanian fields, which in 1939 produced about 35,000,000 bbl in ewes, of the Rumanian civil consumption. However, these fields arc supplying and have supplied for years the oil requirements of the neighboring

Jan 1, 1940

By J. W. Ristori, R. V. Whetsel, V. R. Garfias

World consumption of petroleum and related fuels for civil purposes in 1939 was close to 2,024,000,000 bbl., or approximately 110,000,000 bbl. more than in 1938, the United States accounting for 96,000,000 bbl. of the increased amount. With the annexation of Czechoslovakia and part of Poland, civil consurnption in Germany during 1939, notwithstanding sevre rationing in the last four months of the year, was 54,000,000 bbl., or only 1,600,000 bbl. less than in 1938, and domestic production of pctroleum and related fuels was some 34,000,000 bbl. short of civil consumption. The mounting petroleum requirements of the military forces of greater Germany are, of course, not included in these figures of civil consumption. To supply this deficiency Germany now must rely almost exclusively on the Rumanian fields, which in 1939 produced about 35,000,000 bbl in ewes, of the Rumanian civil consumption. However, these fields arc supplying and have supplied for years the oil requirements of the neighboring

Jan 1, 1940

By W. Rostoker

PART of a program of research on the Ti-A1 system1 involved a study of the lattice parameters of the titanium-rich a solid solution, which has a hexagonal close-packed structure. For this work, a 14 cm Debye-Scherrer powder camera and filtered CuK, radiation was used. For each pattern, the parameters were calculated by a least squares solution of the five strongest high angle lines. This provides an accuracy of i0.005A or better. The results are shown graphically in Fig. 1. It will be seen that an unusual change of slope occurs in the curve for the C parameter at high aluminum contents. Such anomalous changes in slope have been recorded by RaynorV or several magnesium-rich solid solutions. The effects were interpreted in terms of a special contribution to the lattice distortion due to factors of electronic origin predicted by Jones." Jones' theory, in substance, suggested that an unusually large expansion of the lattice would begin when the electron per atom concentration in the alloy was increased to a value at which an overlap just began from one Brillouin zone to another. Con-

Jan 1, 1953

By O. C. Wheeler

There was a marked increase in the investigation of undeveloped areas in Colombia during 1936. The Shell company commenced geological and geophysical investigations on an intensive scale in the Upper Magdalena Valley and at the end of the year had several geological and geophysical parties working in that area. These investigations were supplemented by aerial photography and it is understood that negotiations are under way for having this work continued. The Shell is reported to have acquired some options and leases on private properties in the Upper Valley region and in the western part of Cundinamarca. The Socony Vacuum was making preparations to begin seismograph work on its property north of the Sogamoso River, acquired in 1934 from Sefior Luciano Restrepo. This company will probably start drilling on the property during 1937. The Richmond Petroleum Co. (Standard of California) is said to have renewed geological investigations in the Upper Magdalena Valley above Honda. Local Colombian interests took an active part in applying for concessions on nationally owned lands in the area between the Carare and Magdalena Rivers. The application of the Sociedad National del Carare for a concession in this area was granted during the year. Subsequently an agreement was reached between this

Jan 1, 1937

By Arthur Knapp

The economics of fuel oil must be considered in two aspects; viz., fuel oil as one of a number of competitive fuels and fuel oil as a refined product of petroleum. "Fuel oil" is usually defined as that product of petroleum which is used in furnaces for the generation of heat by simple combustion. It is true that any product of petroleum used in an internal combustion engine is essentially a fuel oil, but such oils are not included in the class known as "fuel oil." Fuel Oil as One of Several Fuels For a number of years, the petroleum industry has believed that the petroleum reserves were very limited and that petroleum products would begin to become scarce within a few years. The industry has believed that there would be a gradual but continual rise in prices as a result of this impending scarcity. The industry, therefore, has informed the users of fuel oil thai., once they were eliminated by price, they were eliminated for all time. The petroleum industry believed and made the consumer believe that there would never be any appreciable recession in price which would make it

Jan 1, 1928

A severely technical article, however well written, can not be an agreeable form of literature. It suffers from the defects of its qualities. One defect is a congestion of language, due to a multiplicity of adjectival nouns. The sentences are packed with words of unpleasing sound, charged with complex ideas, crowding one another so closely that the phraseology moves like an ice-pack in Bering Sea or a log-drive in a river; the undercurrent of meaning may continue to move, but the surface is obstructed. This verbal congestion is made evident by ugly compoundings, many of which are adopted by the technical writer in the mistaken belief that they give directness to his statements. For example: A unanimously approved scheme "A scheme unanimously approved " The continuous temperature record "The continuous record of temperature " To stimulate interest in synthetic plant construction "To stimulate interest in the construction of synthetic plants " In smelters reverberatory-furnace firing with powdered coal has been practised for a decade. "In smelting, the firing of reverberatory furnaces with powdered coal has been practised for a decade." A tar consumption of one pound per ton "A consumption of tar at the rate of one pound per ton " A mechanical ventilating system

Jan 1, 1931

By M. A. Hunter

THIS paper gives the results of an investigation of the specific resistance and temperature coefficient of the electrical resistance of nickel and its important alloy, monel metal. For most of the pure metals, the temperature coefficient of resistance is approximately 0.0004 per degree centigrade at 2.0° C. Nickel and iron, however, are exceptions. This property is important as it gives us good material for the construction of thermometers and other instruments involving electrical control. A summary of information on this subject has been published by the Bureau of Standards.1 The present experiments antedate this publication by several years and as the information obtained is not contained in it, the results of the experiments are published as additional information. ELECTRICAL PROPERTIES OF PURE NICKEL It is generally conceded that the lowest values for electrical resistance are obtained in the purest metal. In the case of nickel, the best material obtainable is electrolytic nickel, which contains approximately. 99.80 per cent. nickel, 0.15 per cent. iron, and 0.05 per cent. copper. Any cobalt that may be present is included in the nickel figure. If the electrolytic sheet has been deposited without intermission, it is possible to cut a section from the sheet and roll it into wire without melting. By this means a nickel wire may be obtained that is uncontaminated by any of the impurities always taken up by nickel during melting.

Jan 5, 1922

By S. Y. Han

INTRODUCTION More than 97% of the total uranium production of the United States comes from sedimentary deposits (1). These sandstone deposits were formed by reduction of migrating uranium-bearing solutions from volcanic silicate rock sources. Such deposits occur in two major forms, either as relatively flat, lens-like deposits or as crescent- shaped roll front deposits. The lens-like deposits are found as discrete masses enclosed in reduced sandstone which is generally surrounded by oxidized sandstone. The roll front deposits are found along crescent-shaped interfaces between reduced and oxidized sands tone (2). In-situ mining of selected sedimentary deposits has proven to be a viable method of extraction and competitive with conventional mining for relatively deep low-grade ores (2). In in-situ leaching, uranium is recovered by drilling injection and collection wells in the ore body, pumping a suitable lixiviant to dissolve the mineral, extracting uranium from the pregnant solution by ion exchange, and finally regenerating and recycling the lixiviant. Even though there is increasing interest and practice in developing the in-situ technique for obtaining uranium values from deeper, lower-grade reserves, there is a lack of knowledge of the basic leaching kinetics and combined transport processes. In-situ leaching operations, in general, appear attractive for the following three general types of deposits (2): (1) low-grade surface dumps or deposits which lie above the natural water table,

Jan 1, 1983

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Jan 1, 1907

By H. D. Hoskold

This instrument, shown in Fig. 1, is not generally known, though it has been used in England, and found very practical, handy and useful in work not requiring a transit or theodolite. It is not only a good miner's dial, but a circumferentor as well; that is, it can measure horizontal angles like a theodolite. The magnetic bearings are conveniently read on the inward-beveled upper divided circle; while another circle, graduated on the base-plate, is used for reading the horizontal angles with a vernier. Two leveling spirit-bubbles are sunk in the same base-plate. The vertical divided semicircle is attached to the compact-box by two short axes, which permit the semicircle, with its plain sights, to be turned down to a horizontal position, and rest upon a pin, which relieves the axes from strain. This adjustment gives a clear view of the needle and vernier, and protects the instrument from injury, when carried through low mine-workings. A groove in the semicircle receives a sliding-bridge which carries the plain sights, and a vernier for reading vertical angles. A ball-and-socket-headed tripod is used; but sometimes the instrument is mounted on parallel-plates and level-ing-screws; and sometimes a telescope is attached, instead of the plain sights. The instrument is admirable for all such Mexican surveys as Mr. E. A. H. Tays describes ;l and saves so much time and labor as to be vastly superior to the less accurate hanging-compass called by him a " bully " instrument. If the hanging-compass was ever used in England, it has long since given way to more modern and superior instruments.

Jan 1, 1905

By B. Ladanyi, B. Hoyaux

One of the most important problems in underground works is the assessment of the stability of underground openings and the determination of loads on eventual supporting structures. Under certain stress conditions, a hard and sound rock around an unlined opening may show a tendency to rock bursting, which can be prevented by appropriate measures. On the other hand, a less competent rock even if it fails in a less violent manner may give rise to a rock load because within limited regions surrounding the opening, the failed material may have a tendency to flow into the opening; this condition should be prevented by designing a proper supporting structure. The stability of the opening, as well as the value of the design loads acting on the supports in the latter case, depends clearly on the shape, extent, and location of the failed regions, which are often called “plastic zones.” It has been known for some time how the plastic zones develop in some very simple cases, such as in the case of a circular opening in an elastic ideally plastic medium subjected to a nongravitational stress fie1d.l However, to the knowledge of the authors, no information has been available up to now about the extent of the plastic zones in a more general case and for rocklike media. ASSUMPTIONS ON ROCK BEHAVIOR MADE IN THE CALCULATION The solution shown in this chapter is valid for a horizontal tunnel of circular cross section driven through a rock medium at a finite depth.

Jan 1, 1970

By Edward H. Robie

Engineers' Centennial THIS summer, in Chicago, will be celebrated the "Centennial of Engineering" and half a hundred engineering societies will have meetings of one kind or another in the two weeks following Labor Day. It is really the 100th anniversary of the founding of the American Society of Civil Engineers. Centennial of Engineering is merely a convenient label to put on the celebration of 100 years of engineering progress in this country since the ASCE was founded. Engineering, of course, is much older than is thus indicated-thousands of years older. But Americans have a penchant for dramatizing progress by celebrating assumed anniversaries. Four years ago a special 30 stamp was issued on which a Brahma chicken was prominently displayed, with the legend, "1848-1948. Centennial of the American Poultry Industry." We feel reasonably sure that the first dozen eggs was sold considerably earlier than that. Until a hundred or so years ago engineers were generally classified as either military or civil. Apparently a group of civil engineers met for the first time in Augusta, Ga. but no records were kept and the first meeting of which we have definite knowledge was at Barnum's Hotel in Baltimore, Feb. 11, 1839. Forty engineers were present and they decided to form a society. Among the aims of these engineers was "the greatest amount of useful effect at the smallest cost," which is as good a slogan for the engineer of today as it was 113 years ago. It was mentioned that the existence and prosperity of the society depended in no small degree on "the personal conduct and exertions" of the members. "Talents and respectability are preferable to numbers ... from too easy and promiscuous ad mission, unavoidable, and not infrequently incurable, inconveniences perplex most societies."

Jan 1, 1952

Jan 1, 1887

Jan 1, 1953

Jan 1, 1953

The Pueblo plant receives its principal supply of iron ore from the Sunrise mine, located in Platte County, Wyo., and Iron Mountain, southwest of Cedar City, Utah. Limestone from Monarch quarry located on the continental divide above Salida, Colo., is shipped into Pueblo to be used as a flux. Of importance to the successful operation of the blast furnace plant is the ore preparation unit at Pueblo. Due to the geologic structure of both the Utah and Wyoming deposits, the ores, both high in grade, are quite variable in chemical and physical nature.

Jan 11, 1953

E. S. MOORE (author's reply to discussion*).-I have read with much interest Dr. W. F. Smeeth's criticism' of my article on the air blasts in the Kolar Gold Field, India. However, before answering the questions he asked, I should like to suggest that possibly the phrase "difference of opinion" might be substituted for the word "misapprehension" when applied to my statement that the matrix of the conglomerate resembles a hornblende schist. This conglomerate is certainly regarded as a metamorphosed sediment. Dr. Evans, who has had wide experience with metamorphic rocks, has regarded this as a clastic rather than an autoclastic rock and mentions it as a probable glacial deposit2 and similar to the Lower Huronian conglomerate of North America. I was greatly impressed by the similarity between this rock and the bands of Huronian conglomerate in the United States and Canada where metamorphism has rendered the matrix of the rock schistose. It was scarcely intended that the word basal, as used in my text, should be extended to the Kolar field, although possibly it may be equally applicable there. The word is so frequently used on this continent for the Lower Huronian conglomerate, which in many places is the basal formation of the predominantly sedimentary Proterozoic group, overlying the more largely igneous Archeozoic rocks, that it was inadvertently used without special stratigraphic significance for the Kolar area. In reply to Dr. Smeeth's question as to how the conglomerate indicates a syncline, it would seem that if there is present in a closely folded area a band of sediment that is younger than the surrounding rocks, it must be in a syncline in those rocks. As to an apparent contradiction in the statement on page 693 regarding the compressive stress, it does not seem that such contradiction exists; I think every one will take the same meaning as Dr. Smeeth has taken, which is exactly what was intended.

Jan 12, 1918