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By Arturo Ressi di Cervia

"The Construction of the Thrust Pits for Jacking of the I-90 Tunnel for the Central Artery/Tunnel Project (Part of Contract No. C09A4) in Boston MA was nominated for DFI’s 2002 Outstanding Project Award. In the judging, the project and the specialty subcontractor, Treviicos Corporation, was chosen for a Special Recognition Award. INTRODUCTIONBoston’s Big Dig, as the construction of the underground artery became known, is undoubtedly the largest urban construction project of this century.The Central Artery/Tunnel Project, or CA/T, to call it by its proper name, runs approximately eight miles through the heart of Boston, five miles of which are built underground while maintaining traffic on the elevated existing structure, while at its southern end I-90 is extended to Logan airport under active rail lines, Fort Point Channel and Boston Inner Harbor.Since the alignment of the road closely parallels the shoreline as it existed in colonial times, the cut and cover construction had to contend with substantial portions of filled ground, not to mention existing subway lines, live utilities, building foundations and, last but not least, the irritable Boston drivers and litigious adjacent property and business owners.Consequently, while it is impossible to single out the most difficult or challenging contract, the jacking of the tunnels of I-90 under the live rails of Amtrak certainly will rank high on the list.Never before, anywhere in the world, was an attempt made to jack tunnels of this size: the South Bay Interchange consists of three 78 feet (24 m) wide by 38 feet (11.6 m) high tunnels, the shortest of which is 167 feet (51 m) long. TECHNOLOGYIn order to achieve this engineering feat it was necessary to consolidate the soil under the track to prevent it from moving or settling during the jacking process. After a detailed analysis of the geological profile to be traversed it was decided that freezing was the most suitable method, since it could be applied to the full range of soils present on the proposed alignment."

Jan 3, 2003

By G. H. Anderson

During an investigation of the copper-rich portion of the copper-silicon-iron system as part of an extensive research program on P.M.G. alloys, which was begun in 1937 in the research laboratory of the Phelps Dodge Corporation, it became apparent that the binary copper-silicon system below 7 per cent Si needed revision, therefore an investigation was undertaken. Both X-ray methods and microscopic technique were employed. Despite the many investigations that have the clarification of this system as their object, no two successive reports on the system have agreed in placement of the alpha-phase solubility limit, and uncertainty about the secondary phase first to appear has been voiced several times.3,4,5 It was therefore not surprising, when T. Isawa's6 and M. Okamoto's7 works were reported at the time we were finishing up our experimental work, to find essential disagreement between their results and ours. But when C. 5. Smith's latest work on the copper-silicon systema was published just as we were finishing our laboratory report, it was indeed gratifying to find that the latter's diagram and ours checked in all essential features, except the temperature of the peritectoid line above 830" C. Many attempts were made to retain the beta phase during the present investigation, but none was successful. Isawa,6 however, reports that he has been able to obtain X-ray photograms of the beta phase. The structure, he states, is body-centcrcd cubic with a lattiee constant of 2.848 ,&. at 7.2 per cent Si. Okamoto7 and Smith8 both use the designation Kappa for the hexagonal phase, and to avoid confusion this designation will he adhered to in the present paper. Preparation of Samples The alloys were melted in vacuum in a high-frequency furnace. from copper cathodes containing 99.98 per cent Cu, and specially refined silicon supplied by The Electro Metallurgical Co. This silicon is stated

Jan 1, 1940

By G. H. Anderson

During an investigation of the copper-rich portion of the copper-silicon-iron system as part of an extensive research program on P.M.G. alloys, which was begun in 1937 in the research laboratory of the Phelps Dodge Corporation, it became apparent that the binary copper-silicon system below 7 per cent Si needed revision, therefore an investigation was undertaken. Both X-ray methods and microscopic technique were employed. Despite the many investigations that have the clarification of this system as their object, no two successive reports on the system have agreed in placement of the alpha-phase solubility limit, and uncertainty about the secondary phase first to appear has been voiced several times.3,4,5 It was therefore not surprising, when T. Isawa's6 and M. Okamoto's7 works were reported at the time we were finishing up our experimental work, to find essential disagreement between their results and ours. But when C. 5. Smith's latest work on the copper-silicon systema was published just as we were finishing our laboratory report, it was indeed gratifying to find that the latter's diagram and ours checked in all essential features, except the temperature of the peritectoid line above 830" C. Many attempts were made to retain the beta phase during the present investigation, but none was successful. Isawa,6 however, reports that he has been able to obtain X-ray photograms of the beta phase. The structure, he states, is body-centcrcd cubic with a lattiee constant of 2.848 ,&. at 7.2 per cent Si. Okamoto7 and Smith8 both use the designation Kappa for the hexagonal phase, and to avoid confusion this designation will he adhered to in the present paper. Preparation of Samples The alloys were melted in vacuum in a high-frequency furnace. from copper cathodes containing 99.98 per cent Cu, and specially refined silicon supplied by The Electro Metallurgical Co. This silicon is stated

Jan 1, 1940

By H. Herman, M. E. Fine

Kinetics of reversion and reformation of GP I were studied resistometrically in Al-1.7 at. pct Cu. The reversion process is over in roughly 1/2 minute at 205 "C irrespective of the amount of primary aging. After reversion the occurrence of an incubation time before reaging begins has been substantiated. The reaging kinetics is drastically accelerated by plastic deformation to the specimen. An incubation time is observed only if the specimen is aged before reversion. The incubation time and the effect of plastic deformation indicate that nucleation of GP I is heterogeneous. Simple clusters of copper atoms apparently do not act as nuclei for GP I. AFTER quenching aluminum-rich copper from the solid solution range, Guinier-Preston zones of the first kind, GP I, form very rapidly at room temperature. The rate, largely controlled by the concentration of vacancies, is initially most rapid1 (that is, at the time of the first measurement: 1/2 min) and decreases with time. The nucleation is thought to be athermal. If after aging for several days the GP I is dissolved by reversion at 205°C, according to measurement of Young's modulus an incubation period is observed before GP I begins to form on subsequent aging.2 Yet if the reversion is carried out immediately after quenching, both resistivity3 and modulus changes2 show no incubation effect. The zones which form after reversion have the same structure as those which form after the quench.4 Because of entropy considerations and also the short diffusion time, the solid solution after reversion, 2 min at 205°C, is probably more highly clustered than at the original solution treating temperature, 520" to 550°C. It appears most reasonable to associate with nucleation the incubation time observed on reaging after reversion. A simple cluster of copper atoms, many of which are presumed to be present after reversion, is then not a sufficient nucleus for GP I; a GP I nucleus must contain something in addition to a cluster of copper atoms. The purpose of the present note is to give some additional experimental information concerning the incubation time and rates of reaging after reversion. The existence of the incubation time has been verified by measurement of another property, the electrical resistivity. Acceleration of reaging after reversion by plastic deformation has also been investigated. In acl.dition, the kinetics of the reversion process itself was studied. EXPERIMENTAL Electrical resistance was measured by the poten-tiometric four probe method. The 1.7 at. pct Cu alloy was furnished by the Aluminum Co. of America in the form of 1/2 in. rod. The major impurities reported by Alcoa were Fe (0.002 wt pct), Si (0.003 wt pct), and Mg (0.001 wt pct). Specimens for measuremenl of resistance were prepared by rolling to 0.010 in., cutting 2 by 0.2 in. pieces, rolling the middle pclrtions of these to 0.005 in., and splitting the 0.010 in. sections up to the reduced central section to form current and potential leads. Aluminum extension wires insulated with ceramic tubes were spot welded to the leads. The specimen was supported by the lead wires. The whole specimen assembly was annealed at 500" C in an air furnace for more than 12 hr and then aged at room temperature. This was done to assure quick and complete resolution during subsequent solution treatments. These were carried out in Houghton's "430 Temper Salt" at 520'C for 1 hr. Unless otherwise specified, quenching was accomplished by quickly transferring the specimen from a salt pot to 25°C water. Aging was carried out in a 3 liter dewar of distilled water, rotated and stirred. The temperature was controlled to +0.01°C with a thermomercurial regulator in conjunction with a transistorized relay

Jan 1, 1962

By J. S. Pascover, J. K. Abraham

The influence of the early stages of precipitation on the kinetics and structure of martensite formation in Fe-27Ni and Fe-29.5Ni alloys containing from 0 to 10 pct Ti was examined with X-ray and electron microscopy techniques. The formation of a coherent, ordered preprecipitate had a profound stabilizing effect on the austenite. The Ms was decreased by increased titanium content and aging time up to a critical time. When the critical aging time was exceeded, the Ms was observed to increase markedly. The formation of the clusters was insuppressible and the volume fraction of clusters formed during the quench was a function of the titanium content. Martensite resulting from transformation of the clustered austenite is tetragonal with the c/a ratio increasing with titanium content. A model for the tetragonality is suggested. The morphology and substructure of the m artensite is inter-preted in terms of the above information and the cur-rent models of twinned martensite. ThE ramifications of precipitation in austenite to the properties of austenite have been the subject of numerous investigations. The current research is concerned with the influence of precipitation in austenite on the kinetics and structure of subsequent marten-site formation. In a previous investigation, Abraham et al.1 followed the aging reaction in an Fe-29.5Ni-4.2Ti* (at. pct) alloy using an X-ray diffraction technique. This technique, employing a Guinier camera, provided kinetic measurements through observation of the side band position as a function of aging time. The salient results of this work were: 1) The initiation of precipitation was not suppressed by quenching, i.e., there was a finite cluster zone size at zero aging time; and 2) The hardness of the aged austenite correlated extremely well with the zone size. During the previous work it was noted that the mar-tensite formed after aging was tetragonal, substanti-ating an earlier observation.2 Systematic investiga-tion revealed that the martensite was tetragonal in both the solution-treated then quenched, and the solu-tion-treated, aged, and quenched condition, and, furthermore, that a marked stabilization of the austenite occurred as a function of aging time. The present work is concerned with documenting the tetragonality and the stabilization phenomena as well as the ob- served microstruction with a suggested rationale for the behavior noted. EXPERIMENTAL PROCEDURE The compositions of the alloys are listed in Table I. The analyses were performed after the solution treatment of the strip material. Nickel was determined using the standard dimethy1-glyoxime procedure whereas titanium was determined colorimetrically with hydrogen peroxide and volumetrically by titrating with ferric iron. The materials were melted in a 5-lb vacuum induction furnace, cast into 2-in.-diam ingots, and forged in a temperature range of 950. to 1200°C to 1/2-in. slabs. The three higher titanium containing materials cracked during forging; therefore, to get the alloys into strip form, slices 1/8 in. thick were cut from the slab, homogenized 4 hr at 1150°C, then cold-rolled to a 0.04-in. thickness. The remaining slabs were hot-rolled, homogenized 4 hr at 1065"C, then cold-rolled to a final thickness of 0.03 in. All of the heat treatments were performed under a protective atmosphere of argon. The Ms temperature for most of the alloys is below room temperature; therefore, it was possible to solution treat, quench to room temperature, polish, and then observe the transformation optically on a cold-stage microscope. To determine the effect of aus-tenitizing temperature on Ms, eight of the alloys were treated at two temperatures, 1025" and 1120°C. No measurable variations in Ms were noticed. The remaining alloys were treated at 1025°C. The specimens, : by 5/16 by 0.03 in., were austeni-tized in a vertical tube furnace under a dynamic argon atmosphere. The bottom of the tube was submerged in water for quenching purposes. The question of stabilization that may be operating at room temperature was investigated and found to be negligible. Many of the specimens were held at room

Jan 1, 1970

The industrial relations handbook, by A. Pons. Juta (P.O. Box 14373, Kenwyn 7790). 1989. "'"250 pp. Looseleaf binder. R180 + GST. Industrial laser materials processing. World Business Publications Ltd (4th Floor, Britannia House, 960 High Road, London N12 9RY, England). 1989. 180 pp. £310. Mining 1990. Longmans, Financial Times International Year Books, 1989. 592 pp. £90.00. Innovations in materials processing using aqueous, co/oid and surface chemistry, by F.M. Doyle, S. Raghavan, P. Somasundaran, and G.W. Waren (eds.). 300 pp. $125. Light metals 1989, by P.G. Camp bel (ed.). No. of pp. not available. $150. Process control and automation in extractive metalurgy, by R. Partelpoeg and D.C. Himmesoete. 225 $98. Process mineralogy VIl, by D.J. Carson and A.H. Vassiliou (eds.). 4oopp. $150. Super plasticity and super plastic forming, by C.H. Hamilton and N.E. Paton (eds.). 700 pp. $140. Supera/oys 1988, by S. Reichman, D. Duhl, G. Maurer, S. Antolovich, and C. Lund (eds.). 880pp. $99. Surface modification technologies, by T.S. Sudarshan and D.G. Bhat (eds.). 305 pp. $49. World survey of nonferous smelters, by J .C. Taylor and H.R. Traulsen (eds.). 365 pp. $90. Second Parsons International Turbine Conference. London, The Institute of Metals, 1989.270pp. £40. Mineral processing in the United Kingdom. London, Institution of Mining and Metalurgy, 1989. £25. Today's technology for the mining and metalurgical industries. London, Institution of Mining and Metalurgy, 1989. 623 pp. £60. 1989/1990 E&MJ international directory of mining. Chicago, Mining Information Services (P .0. Box 6500, Chicago, IL 60680, USA). 620 pp. US$95. Advances in project scheduling, edited by R. Stowinski and J. Weglarz. Amsterdam, Elsevier, 1989. 540 pp. Dfl. 270. Proceedings of the 3rd International Conference on Molten Slags and Fluxes. London, Institute of Metals, 1989. 335 pp. £38. Brochure on industrial screens. Obtainable from Philippe Lavernhe, Johnson Filtration Systems S.A., Z.I. Availes-en-Chatelerault, 86538 Naintre, France. 16 pp. Free. Numerical techniques, edited by P. Spiling. London, The Institute of Metals, 1989. 226 pp. £25. Phase diagrams of ternary iron aloys, Part 2, by V. Raghavan. New Delhi, Indian Institute of Metals, 1988. 360 pp. £95 (from the Institute of Metals, London). cas publications These publications are available from the Centre for Resource Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada. Economic aspects of gold exploration: How much is too much, by B.W. Mackenzie and M. Dogget. 30 pp. $10.00. Mineral exploration and mine development potential in Ontario: Economic guidelines for government policy, by B.W. Mackenzie, M. Bilodeau, and M. Dogget. 180 pp. $25.00. Economic potential of base metal and gold mining in Newfoundland: Assessing the impact of regional developmentpolicy options, by B.W. Mackenzie, M. Bilodeau, and M. Dogget. 188 pp. $25.00. Publications of the AusIMM The folowing publications are available from The Australasian Institute of Mining and Metalurgy, P. O. Box 122, Parkvile, Vic 3052, Australia. Prepayment is required with al orders. The AusIMM 1989 Annual Conference 1989. $A 50. Mineral fuel alternatives and the greenhouse efect. July 1989. A$ 35. NQ gold '89. Apr. 1989. $A 50. Second Large Open Pit Mining Conference. Apr. 1989. $A 50. Explo '88. Nov. 1988. $A45. Mineral deposits of New Zealand, edited by Dr D. Kear. Monograph 13. 244 pp. $A 60. Field geologists' manual, compiled by D.A. Berkman. 3rd edition. 1989. : 350pp. $A45. The rocks speak. Essays in geology-some personal responses of a wiling listener, by Haddon F. King. 300pp. $A45.

Jan 1, 1990

HENRY TRAPHAGEN, * Toledo, Ohio (written discussion t).-The occurrence of flakes in steel is a perplexing problem, if we consider this condition as a disease rather than a symptom. But if considered as an exaggerated phase of a common disease, flakes will be recognized as old and well-known enemies. I have frequently found flakes in open-hearth steel, converter steel, and even electric steel; and not only in the so-called alloy steels but in dead soft 12-point carbon castings. In fact, I have some twenty flaky test bars that came from a foundry that manufactures converter steel castings. The physical characteristics of such material are striking in their constancy, for the yield point and elastic limit are always high, the elongation is variable, and the reduction of area is nearly always negligible. Soft steels of this kind can easily be bent to an angle of 150° and the only bad symptom is the appearance of incipient cracks on the surface; when the carbon exceeds 30 points, the bending qualities are seriously affected; and when the carbon reaches the neighborhood of 50 points, the bars are generally pulled short. The elongation is peculiar in that it seems to take place along the whole length of the bar, giving a crinkly appearance such as is found in cast brass and monel metal. Of course, this elongation only takes place in the softer varieties of steel. I have stated that flakes in steel represent exaggerated symptoms of a common disease, and that disease is the presence of higher oxides of iron. In every instance that has come to my attention, this condition is coexistent with the presence of oxides in some form. In open-hearth practice when this condition occurs, almost invariably it will be found that the metal has been loaded with ore or that tons of rusty turnings were being melted. In converter practice, one of three conditions is nearly always present: bad cupola practice, the use of oxygenated pig iron, or faulty tuyeres. With the electric furnace, my experience is quite limited, but the few examples of flaky electric steel that have come to my notice were made from a charge of turnings and low-grade light scrap.

Jan 6, 1919

By R. Rodgers

The Pinto Valley concentrator of BHP Copper Inc. restarted its sulfide mining operations in September 2007 to produce copper and molybdenum concentrates. During the plant production ramp up, the copper/molybdenum circuit quickly reached the copper grade and recovery targets, but the production and quality of the molybdenum concentrate continued to be a challenge. Even though several improvements in the molybdenum circuit were completed, the final molybdenum concentrate did not meet contractual specifications. After reviewing several options to improve grade and reduce contaminants, the installation of three flotation columns were chosen. The column design and construction were done using in-house craftsmen and engineers. Ten days after commissioning, the columns successfully reached a steady operation and began producing molybdenum concentrate to the required specifications, that is, high molybdenum tenors and low copper and iron content. The Pinto Valley operations, are comprised of the Pinto Valley concentrator, the Pinto Valley dump leaching and a solvent extraction/electrowinning (SX/EW) plant. The concentrator operated from 1972 to 1998 when mining and milling operations were curtailed for economic reasons. The SX/EW plant continued operations for copper cathode production. After a cessation of mining operations of almost 10 years, Pinto Valley operations began a restart project in January 2007, to bring the mine and the concentrator back into production. Copper concentrate production started in October 2007 after refurbishing and upgrading the facilities with a new DCS system and filter plant. The daily targets of the concentrator were to treat 56.7 kt (62,500 st) of ore, produce 762 t (840 st) of copper concentrate containing 27.5 percent copper at recoveries of 86 percent and produce 2.2 t (2.5 st) of molybdenum concentrate containing more than 80 percent MoS2.

Jan 1, 2010

By Clinton H. Crane

WHEN I agreed to accept your Committee's suggestion that I talk to you at this meeting on the future of copper, lead and zinc mining, I could not help wondering why I had been chosen to be a prophet. Knowing the pious nature of your committee, I thought I had better look up and see what the Bible says about being a prophet, and what the dictionary definition of a prophet is. The word "prophet" comes from the Greek and is defined as "one who speaks through a divine inspiration." Also, in the Gospel of Saint Matthew, Christ tells us that a prophet is "not without honor save in his own country and in his own house." That gave me pause until I remembered that after all, I had started my professional career as a Naval Architect, not as a Mining Engineer, and consequently, this might be a clue to the fact that the eminent geologists of this society, who know infinitely more about the world's crust than I do, were passed over in this assignment. In thinking back, I then remembered that the first really successful prophet was Noah and that Noah was a Naval Architect. Here then was the answer. One more quotation from the Bible I shall take as my text: In Ecclesiastes, chapter I, verse 9: "The thing that hath been is that which shall be." Now, with this preamble, and not being bound by anything save inspiration, I will proceed to prophesy: As far as the next 15 to 25 years are concerned, from the studies made by

Jan 1, 1947

Discussion of the paper of CHARLES T. MALCOLMSON, presented at the New York meeting, February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 271 to 289. E. W. PARKER, Washington, D. C.-The briquet or boulet, or coalette (whatever name is used) has come to stay as a part of the fuel supply, particularly for domestic purposes. During the past winter I have had some personal experience with the use of boulets made from anthracite coal. All of this winter I have used boulets in my furnacee and in my grate at my home in Washington. One reason for doing so is that we get the boulets at a price considerably cheaper than the prepared sizes of anthracite coal. The fuel has proved entirely satisfactory. One advantage possessed by the boulet is its absolutely uniform size, which makes the ventilation of the firebed practically perfect. The boulets burn until entirely consumed. There is not, even in an open grate fire, if the fire is kept constantly going, any unconsumed fuel passing through the grate bars. The boulets hold their form until entirely consumed and then break away into a clean white ash, with absolutely no clinker. That in itself is a particularly favorable recommendation to the housekeeper. Mr. Malcolmson has mentioned the fact that notwithstanding the smokeless character of anthracite, the boulets made from it emit smoke. The emission of smoke is due to the coal-tar pitch used as a binder. This is particularly noticeable if the fireman is somewhat careless, or wants to save labor, and feeds too much of the fuel on the fire at one time, cooling it down and thus causing an unnecessary amount of smoke. The smoke lasts but a short time, however, and if the fire is fed a little more frequently, with a small quantity of fuel at one time, the smoke is reduced to a minimum. I believe it will not be long before some of our engineers will have overcome the objectionable smoke; and will produce either from anthracite or from the so-called smokeless New River and Pocahontas semi-bituminous coals, a briquet which will be as smokeless as anthracite for all. practical purposes.

Jan 5, 1915

By A. M. A. Mohamed, F. H. Samuel, S. Valtierra, H. W. Doty, A. M. Samuel

"The influence of Fe, Mn, Cu and Mg alloying additions, Sr modification and grain refinement on the microstructure of as-cast and solution heat-treated Al-10.8% Si alloys was investigated using optical microscopy and EPMA techniques. The results showed that the modification effect of Sr diminished with increasing Cu and Mg additions, due to Sr-Cu-Mg interactions. Strontium caused segregation of AlzCu in areas away from eutectic Si regions, and altered the precipitation sequence of the a-Ah5(Fe,Mn)3Siz iron intermetallic from post-dendritic to pre-dendritic, with the phase observed within the a-Al dendrites. Depending upon the alloy Fe and Mn content, a coarser variation (""sludge"") of the a-Fe phase occurred, in the form of polyhedral shaped particles. The AhCu phase dissolved almost completely during solution heat treatment, while Al5Cu2Mg8Si6, sludge, and a-Aln(Fe,Mn)3Siz phases persisted in all alloys, particularly at high Mg and Fe levels. The f3-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, the dissolution becoming more pronounced after solution heat treatment."

Jan 1, 2006

By A. Sadough vanini A. Kami

In this paper, effects of different ageing treatments on the mechanical properties, microstructure and formability of 7075 aluminum alloy have been studied. Forming limit diagrams of the alloy have been obtained for four ageing conditions including T6, OA1, OA2 and O. For this purpose, combination of uniaxial tensile tests and the Erichsen cupping tests with different sizes and shapes of sheet specimens have been performed after each ageing treatment. The highest formability and the lowest formability have been observed at samples with O and T6 ageing treatments, respectively. Also, investigation of precipitated microstructures showed that the size of precipitation particles has a significant effect on the formability of the alloy. Formability improves with coarsening of precipitation particles.

Oct 1, 2011

By Ross Gallinger

In 1997 a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded (i) that Canadian industry and NRCan should fund a small secretariat in Ottawa to support technology transfer in Canada and (ii) that it was important for industry to continue the momentum of MEND on an international scale. The need for INAP (International Network for Acid Prevention) was strongly endorsed by company, university, consultant and government experts from Australia, Canada and the U.S. who were convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP's members to promote the dissemination of successful practices, the identification of knowledge gaps and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry based initiative to globally coordinate research and development in the management of sulfide mine waste. Significant improvements in the management of sulfidic mine materials through knowledge sharing, research and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP.

May 1, 2002

By Rita D. Sylvester

THE BUREAU OF MINES was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve mineral resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to "disseminate information concerning these subjects 'in such manner as will best carry out the purposes of this Act.'" In accordance with that directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau sources. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes Bureau reports and articles published during the period January 1, 1960 to December 31, 1964. It, supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960,2 and the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960.3 It supersedes the annual lists of Bureau publications and articles from January 1 to December 31, 1960,4 from January 1 to December 31, 1961,5 from January 1 to December 31, 1962,6 and from January 1 to December 31, 1963.7 The leading general and technical libraries of the United States maintain files of the Bureau's publications. A list of these libraries appears immediately following this introduction.

Jan 1, 2007

By S. Groudev

Acid drainage waters generated in the uranium deposit Curilo, Bulgaria, were treated by means of a pilot-scale passive system consisting of a permeable reactive multibarrier and a constructed wetland connected in a series. The multibarrier had a total volume of 23 m3 and consisted of an alkalizing limestone drain and an anoxic section for microbial dissimilatory sulphate reduction, bio-sorption and additional chemical neutralization. The waters had a pH in the range of about 2.5 ~ 4.0 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in agriculture and/or industry. The water flow rate through the multibarrier varied in the range of about 1 ~ 17 m3/24 h, reflecting water residence times of about 300 ~ 18 hours. An efficient removal of pollutants was achieved by the multibarrier during different climatic seasons, even during cold winter days at external air and water temperatures close to 0oC. The multibarrier effluents were enriched in dissolved organic compounds and in some cases still contained manganese and iron in concentrations higher than the relevant permissible levels. These pollutants were removed in the constructed wetland as a result of the activity of different heterotrophic microorganisms, including some bacteria able to oxidize the bivalent manganese and iron ions to Mn4+ and Fe3+, respectively.

Jan 1, 2014

By H. C. Wade

"Description and UseDischarge liners or pulp lifters as they are sometimes called are a trough type liner used at the discharge end of the mill where ground ore passes to the trunnion.There are basically two methods of discharging pulp. The First and most common is the overflow method. Here ground ore travels from the feed to the discharge end where it exits through the discharge trunnion in an overflowing manner, hence the name ""overflow"". (See Figure I) The second method of discharging pulp is the grate method. With this method you block-off the trunnion and hold the ore inside the mill for a longer period of time. This allows only the desired size of ore out of the mill. Ore passes through the grate liners, into the Vibrathane Discharge liner, and finally down to the trunnion. Greater control of the ore size results wit1 this method as compared to the overflow method and it also eliminates reclassifying and regrinding. (See Figure 2)Types in UsePresently the majority of discharge liners in use today are rubber. (Metal insert and rubber covered) In some extremely course applications steel and nihard are used."

Jan 1, 1980

By R. F. Zaffarano

Intergrated energy balances and energy flows were constructed and quantified for State, regional, and national levels from four separate supply and demand commodity balances for coal, dry natural gas, petroleum and natural gas liquids, and utility electricity. These commodity balances were integrated by source and sectors through conversion and aggregation of their components to energy equivalents expressed in British thermal units (Btu). A summarization of the total gross energy components of supply and demand for commercial energy derived from direct fuels, hydropower and nuclear power, based on individual States and regions, is tabulated for 1960 and 1965. Pertinent computerization details and more than 500 individual State and regional printout tables, in both original commodity units and Btu's, are shown. Using these data, energy flows between States and regions were calculated to identify surplus and deficit energy areas. Report emphasis is on the conceptual aspects of integrated energy balances, rather than on the development of missing State energy data.

Jan 1, 1969

By J. O. Brittain, E. Lautenschlager

Yield point measurements were made on polycrys-talline specimens of a iron deformed various amounts at 770, 1950, or 273°K, aged, and redeformed at 77: 195°, or 273°K. When the prestrain temperature is lower than that subsequent to aging, the yield point return is suppressed relative to specimens deformed at the same temperature both before and after aging. The degree of suppression is a function of both the magnitude of prestrain at the lower temperature and the difference between the deformation temperatures before and after aging. It is proposed that the suppression is caused by the formation of dislocation barriers during the initial low-temperature deformation. The aging kinetics of polycrystalline a-iron wires deformed at 77o or 303oK were studied at 44 " and 64 "C using internal friction measurements. No change was noted as a result of the difference in prestrain temperature. IN an earlier investigation1 it was observed that the return of the yield point was suppressed when a poly-crystalline specimen of a iron was plastically deformed at 77oK, aged at room temperature, and subsequently tested at room temperature. In order to investigate this observation, a research program was undertaken to measure the effect of prestrain temperature on the strain aging of a iron.' According to Thomas and Leak,3 return of the yield point and internal friction are similar measures of strain aging since both are dependent on solute atoms leaving the solid solution. The decrease in internal friction as a function of aging time is indicative of the removal of solute atoms from the solution, while the return of the yield point as a function of aging time gives the rate of arrival of solute atoms at the dislocations. According to Cottrell and Bilby,4 the solute atoms create an "atmosphere" which locks the dislocations and causes a return of the yield point upon restraining. In this experiment, both methods of measuring strain aging were employed in order to have two independent measurements of the strain aging phenomenon. In a previous study,5 the strain aging kinetics of a similar lot of a iron were measured for specimens which were prestrained and tested at the same temperature over the range of 77" to 273°K. Although some differences were found in the correlation of the two methods employed for measuring strain aging, the kinetics of strain aging were unaffected by the change of prestrain and test temperature. In another study,6 dislocation line tension and the density of the solute atmosphere were found to contribute to the return of the yield point when ingot iron specimens were prestrained at 303°K and tested at a lower temperature, namely 77°K. This paper is concerned with changes in strain aging kinetics produced by pre-straining at 77" to 303°K and testing at either the prestrain temperature or at higher temperatures up to 273°K. EXPERIMENTAL PROCEDURE The polycrystalline a iron specimens used in both the tensile and internal friction tests were 0.033-in. diam ingot iron wires, wet hydrogen treated and re-carburized. A more detailed procedure for processing a 3/16 in. ingot iron rod (nominal wt. pet composition: Fe - 0.013; C - 0.0125; Mn - 0.023; Si -0.005; P - 0.0023; S - 0.11; Cu - 0.004 N) to 0.033 in. diam specimens containing approximately 0.020 wt pet C and no detectable nitrogen with a grain diameter of 0.033 to 0.040 mm is given elsewhere.5 Immediately prior to testing, specimens were solution treated for 15 min at 700o ± 2°C in a static vacuum of less than 50 ?. of Hg and rapidly quenched into an ice-water bath while still enclosed in a 3 mm quartz vial. The internal friction specimens had 8-in. gage lengths and the tensile specimens had 2-in. gage lengths. The wires used as tensile specimens were first run as internal

Jan 1, 1962

By M. Mujahid, A. Maqsood, M. H. Asghar, K Iqbal

"Thin film multilayer anti-reflection coatings (Si02/Si/Si02) having thicknesses 286/571/143nm were deposited by RF magnetron sputtering deposition technique on 0.5mm thick Si(100)-substrates. Post-deposition annealing is also carried out in the temperature range 150-650°C for 4hr at the rate of 10°C /min. Si Optical window was designed at 4.21lm wavelengths and correlated with modeling software. The films are transparent in the 3-51lffi band of the electromagnetic spectrum, firmly adhered to the substrate. The prepared multilayer thin films are characterized optically and structurally using a spectrophotometer, an atomic force microscope, x-ray diffraction and a scanning electron microscope. Optical and structural characterizations show that the %transmittance is between 60% and 75%, no appreciable change in crystal structure and roughness of coatings vary between 9 and 25 nm when annealed in the temperature range of 150-650oC. Local elemental characterization on the surface of the thin film was carried out using energy dispersive spectroscopy. The quantitative result of energy dispersive spectroscopy has also shown that the ratio of Si to 0 on the film is 0.67: 1.IntroductionSi02 thin films have unique properties in the interfaces with Si and most studied materials in the field of microelectronics and optical devices [1]. Multilayer thin films are using nowadays in the design and fabrication of the shrinking systems with a variety of fields such as optoelectronic devices. The physical properties and parameters can be controlled at scales of microns down to nanometers by using RF magnetron sputtering system [2].Silicon and Silicon dioxide are used as coating materials [3]. These thin films are laid on top of each other in SiO2/Si/Si02 order by RF magnetron sputtering on top of a substrate as given in Table 1."

Jan 1, 2012

The Institute was founded in 1894 as the Chemical and Metallurgical Society of South Africa. In 1904 it was reconstituted as the Chemical Metallurgical and Mining Society of South Africa and in 1956 it became the South African Institute of Mining and Metallurgy. The objects of the Institute are to advance the science and practice of mining and metallurgy, to afford opportunities for the interchange and recording of knowledge of mining and metallurgy and to ensure high standards of professional conduct and competence. Membership benefits include monthly issues of the Journal of the Institute, monthly General Meetings at which papers are read, symposia, excursions to mining and industrial concerns and the use of club facilities at Kelvin House. Technical journals received on an exchange basis are available to members at the Johannesburg Public Library. The current membership of the Institute is over 1,600. Membership applications are accepted from suitably qualified persons and the requirements for entrance to the various grades of membership are summarised below. Fellows shall not be less than 30 years of age, shall be university graduates in pure or applied science or shall produce evidence to the satisfaction of the Council that they have successfully completed a co-ordinated course of study in pure or applied science of at least three years' duration at an approved university or institution deemed by the Council to be of equivalent status. Members shall have been employed in senior technical positions in important mining or metallurgical undertakings for at least five years or they shall have practised as mining or metallurgical consultants for at least five years. They shall be practising their profession at the time of application. Entrance fee RI0.00, Annual subscription RI7.00. Letters of designation: F.S.A.I.M.M. Members shall be not less than 25 years of age and shall be university graduates in pure or applied science, or shall have successfully completed co-ordinated courses of study in pure or applied science of at least three years' duration. They shall have been engaged in work of an approved technical character in the mining or metallurgical industries, of which not less than two years shall have been in positions of responsibility. A candidate shall be practising his profession at the time of his application. Entrance fee R8.00, Annual subscription RI5.00. Letters of designation: M.S.A.I.M.M. Associates shall be not less than twenty-five years of age, and shall have been engaged in positions of responsibility in, or associated with, the mining or metallurgical industries for periods of not less than three years. If, however, the candidate for admission to the higher grade of Associate, is at the time of his application, already a Student, he need satisfy the Council only that he is, at the time of his application, engaged in a position of responsibility in or associated with the mining or metallurgical industries. In all cases the applicants shall satisfy the Council that they are fit and proper persons to become Associates. Entrance fee R8.00, Annual subscription RI5.00. Graduates shall be not less than 21 years of age and shall be university graduates in pure or applied science, or have completed co-ordinated courses of study in pure or applied science of at least three years' duration at an approved university or institution. They shall not remain Graduate members after attaining the age of 30 years without the permission of Council. Entrance fee R2.00, Annual subscription R10.00. Students shall be persons not less than 18 years of age who are being educated or trained in a manner approved by the Council, to occupy a technical position in or associated with the mining or metallurgical industries and who, furthermore, shall not have attained the qualification required for a higher grade of membership. They may remain Students until they have obtained the necessary qualifications for transfer to a higher grade of membership, but not after the end of the Institute's financial year in which they attain the age of 28 (twenty-eight) years. They shall then transfer to a higher grade to retain membership of the Institute. The Council may relax the provisions of this clause in such cases as it considers appropriate. Entrance fee nil; Annual subscription R3.00. Other. The Council has the power to elect to the grade of Fellow or Member, candidates who may not fulfil all the requirements for entrance to these grades but whose status, professional achievements and practical experience in mining or metallurgy justify such election. Applications. Requests for membership application forms should be addressed on the attached form to the Secretary, South African Institute of Mining and Metallurgy, P.O. Box 61019, Marshalltown, Transvaal.