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By P. R. Hervey, J. W. Foise

Quartz is the second most widely used electronic material, with approximately 3,000 t (3,300 st) of single crystals used each year. Most of the quartz used in electronics is synthetic and is manufactured using a technique called hydrothermal growth. This paper reviews the basics of hydrothermal growth, the feedstocks used for these crystals and the challenges to improving the growth process. This paper also reviews the processing of these crystals, the markets and applications where they are used, and the global outlook for these markets.

Jan 1, 2002

By P. T. Carter, A. B. Murad, H. B. Bell

N. A. Gokcen (Michigan College of Mining and Technology, Houghton, Mich.)—The activities of silica, represented in Fig. 5 for the systems MnO-SiO2 and CaO-SiO2, are in disagreement with the established binary phase diagrams. At Ns102 = 0.50 in MnO-SiO2, and at Ns102, = 0.65 in CaO-SiO2, each binary system is saturated with respect to silica at 1550°C, and therefore as102, is unity in each case. The curves for as102 (FeO-SiO2) and as102, (MnO-SiO,) should nearly co-

Jan 1, 1953

The co-operation of the members of the Institute is earnestly sought by the Committee on Nominations, recently appointed by the Board of Directors, in its work of formulating a ticket for officers and places falling vacant in the Board of Directors in February, 1916. The Committee must present the official ticket of nominations to the Board of Directors at its October meeting. Members are, therefore, urged to send promptly their nominations for officers and Directors in order that the Committee may have an opportunity to give them full consideration. The officers to be elected at the annual meeting in February, 1916, are: One officer, known as Director and President. Two officers, known as Director and Vice-President. Five officers, known as Director. The officers of the Institute whose terms expire are as follows: President, William L. Saunders (not eligible for re-election). Past President, Charles F. Rand. Vice-Presidents, Thomas H. Leggett, District 0; Fred W. Denton, District 4.

Jan 9, 1915

[Appalachian Petroleum Section: Chairman: Robert H. Edele, 1st V.C.: Robert Vutech, 2nd V.C.: Robert Tullis, Sec.-Treas.: Frederick T. Solomon. Meets last Tuesday of each month in Charleston, W. Va. Balcones Section: Chairman: Dr. Frank W. Jessen, 1st V.C.: Gilbert M. Andreen, 2nd V.C.: Lloyd N. Johnson, Seo.-Treas.: W. C. Vercellino. Big Horn Basin Subsection: Chairman: B. E. Yester, 1st V.C.: Robert J. Woodhall, 2nd V.C.: Herbert A. Koch, Secretary: Dean Costello, Treasurer: Thomas W. DeLong. Meets 2nd Wednesday; alternating between Cody and Worland. Billings Petroleum Section: Chairman: George O. Ellis, 1st V. C.: Robert L. Spottswood, 2nd V. C.: Robert M. Watkins, Sec-Treas.: Joseph H. Bato. Meets 5:30 p.m., 3rd Tuesday at Billings Press Club.]

Jan 1, 1961

The Institute is custodian of funds for support of numerous gold medals and prizes and has representatives on boards awarding still others. Details regarding the Institute Awards are given below. The Institute is represented on the boards of the John Fritz Medal, the Hoover Medal, and the Alfred Noble Prize, in conjunction with the three national societies of Civil, Mechanical and Electrical engineers; and, also on the board of the Washington Award, on which the Western Society of Engineers also is represented.

Jan 1, 1940

By K M. Watling, F M, G K. Parker

Surface enhanced Raman scattering (SERS) spectroscopy at surfaces under electrochemical control has been applied to elucidate the adsorption of thiol collectors. SERS spectroelectrochemical studies at coinage metal electrodes have been carried out on ethyl xanthate and three iso-xanthates, O-isopropyl-N-ethylthionocarbamate, 2-mercaptobenzothiazole, diisobutyl- dithiophosphinate and butylethoxycarbonylthioura. For each collector, adsorption occurs via charge transfer to form a metal-sulfur bond and, in situations for which the reversible potential of the formation of the bulk phase is known, at underpotentials.

Jan 1, 2005

By Joseph B. Darby, Paul A. Beck

IN isothermal sections of several ternary systems, the a-phase was found1 to extend in the form of a relatively narrow elongated field, connecting the U-phases that are present in the adjoining binary systems. This was interpreted in accordance with the conception that the U-phase is an electron compound and the ternary U-phase fields were shown in several systems' to extend approximately in the direction of constant average d-shell electron vacancy number per atom. ' However, in the various isothermal sections of the Fe-Cr-Mo system" the ternary a-phase field was

Jan 1, 1958

By F. H. Buttner, E. R. Funk, H. Udin

A. P. Greenough (University College, swansea, Great Britain)—I have recently made some experiments on the deformation of silver wire at high temperature in an atmosphere of oxygen-free nitrogen. The observa-tions which 1 made confirm the main conclusion of this paper, that the most satisfactory mechanism so far suggested to explain the deformation which takes place

Jan 1, 1953

The Joint Economic Committee's subcommittee on international payments and exchange has recommended that, following international monetary reforms, the law which prohibits private possession of gold by American citizens be repealed. The subcommittee recommendation called for reforms to enhance the role of special drawing rights in international monetary affairs and downgrade the role of gold. Special drawing rights, also known as "paper gold", are on artificial reserve with the International Monetary Fund (IMF) which distributes them to member nations in proportion to their economic importance in the world economy. The special drawing rights are then used to settle debts between nations in the same manner as gold or currency. The subcommittee said that under the reforms now being discussed special drawing rights would be acceptable in lieu of gold among the member countries of the IMF.

Jan 1, 1973

By Knezicek Zeljko, Knezicek Tihomir

Lignite open cast mine "Dubrave" is the largest lignite mine in Bosnia and Herzegovina. The open cast mine was designed with two external waste dumps. Waste dump "West" is the major dump, while "Cajici" dump is used for dumping waste taken from leveling the terrain. The major waste dump contains 14.6 million cu.m. of waste, while the side waste dump contains 3 million cu.m. of waste. Existing situation with available sites for depositing the waste shows that additional space for dumping the waste must be provided. Three options can be taken into consideration. The fact is that none of the three options are suitable for the current production situation. This article deals with the optimization process for obtaining the optimal variant where a waste dump can be located and selection of the most valuable option.

Jan 1, 2002

The incidence of colliery disasters has highlighted the need for more centralised and directed coal mining safety research in Queensland, with particular impetus from explosions at Box Flat in 1972, Kianga in 1975 and Moura No 4 in 1986. Inquiries which identified the likely causes recommended measures and, research and two outcomes have been the present Mines Safety Research Advisory Committee and The Safety in Mines Testing and Research Station at Redbank, near Brisbane, dealing with all mining problems, coal and metalliferous. Already, important research into ignition and explosion and other health and safety matters has been accomplished; the Station has become an accredited testing laboratory; and international recognition has been achieved. Now the advisory, testing and research arms are soundly in place to pursue preventive investigations and be ready to provide assistance in any emergencies.

Jan 1, 1991

By G. Davis

It is well known that anticipated mineral prices can have an overwhelming effect on a property's expected value. However, price movements throughout the life of a project also affect value. Thus, it is necessary to not only estimate the expected commodity price at the start of a project but also the manner in which that price is likely to fluctuate throughout the project's life. This paper provides a simple method of incorporating mineral price movements into mineral project valuations.

Jan 1, 1997

By M. J. Friedel, D. F. Scott, T. J. Williams

In an effort aimed at monitoring mining-induced stress changes that may influence ground failure, the US Bureau of Mines conducted a series of active 3-D seismic tomographic surveys at the Homestake (Lead, South Dakota) and Lucky Friday (Mullan, Idaho) mines. Existing rock bolts were used to mount geophones and as strike points for introducing seismic energy using a 3.6 kg sledge hammer. Travel time measurements were recorded spanning up to 160 m between drifts at several levels. The tomographic uncertainty was minimized by computing iso-velocity surfaces of constant probability based on statistics from multiple reconstructions and a threshold criteria. Periodic imaging using tomographic velocity surfaces demonstrated that temporal and spatial changes in the local stress field occurred in response to ground failure and stope advancement at a gold and silver mine, respectively. Keywords: Temporal imaging; Mine-induced stress; Seismic tomography; Geophysics

Sep 9, 1996

By Brian Mason

Wire Ropes in Mines. Proceedings of a conference held at Ashorne Hill, Leamington Spa, Warwickshire, September, 1950. Published by the Institution of Mining and Metallurgy, Salisbury House, London, 1951. 828 P. $7.00-The volume contains 18 pages on the manufacture and properties of rope wire and wire ropes. In addition, wire rope practice in Britain, Ontario, the Witwatersrand, The United States, South Africa, and other countries are discussed. Testing, government regulations, and inspection are also treated. The book contains a three day discussion on these subjects complete with a summary of conclusions and recommendations. Heating Ventilating Air Conditioning Guide 1952. Published by the American Society of Heating and Ventilating Engineers, New York, 1952. 1496 P. $7.50.Contains a technical data section of reference material on the design and specification of heating, ventilating and air conditioning systems. Also has a section containing information on equipment and manufacturers. An index to technical and equipment sections is included.

Jan 1, 1952

By David M. Hopstock

The performance of the most common type of low-intensity dry magnetic separator is analyzed on the basis of fundamental physical principles. Expressions are developed for estimating the optimal choice of design and operating parameters for beneficiation of magnetite ores. By proper choice of these parameters either a high-grade concentrate or a low-grade tailing can be produced from an incompletely liberated feed.

Jan 1, 1976

By N. T. Rempe

The underground voids that result from mining provide opportunities for deep geologic waste disposal (DGWD). Such disposal could solve many environmental problems. DGWD takes careful planning, technology transfer and true partnership between waste generators and mine/repository operators. The US government is now planning on using specially mined excavations to dispose of radiotoxic and mixed waste. Using the experience gained from the domestic projects that are now in preparation and from foreign repositories that are now in operation, US mines can claim their rightful share of the growing market for DGWD.

Jan 1, 1997

By A. Tanaka, K. G. Carroll

The existence of local room-temperature plastic flow in germanium, which has been a subject of controversy for nearly two decades, has recently received renewed attention, albeit no more agreement than hitherto. Phenomenologically one major facet of the problem has been reduced to the question whether or not indentation can be effected in germanium without the introduction of cracks. That plastic flow can be induced at room temperature by fracture appears to have been rather convincingly demonstrated recently by Suzuki and Kamada and by Noble and Henisch.1 The literature contains both direct and incidental references to Vickers and Knoop indentations showing no cracks, within resolution of optical microscopy. Recently, however, following a controversy on the subject,2,3 johnson4 made a study of indentations produced by spherical indenters and concluded that these are accompanied by cracking. This study in-

Jan 1, 1969

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Jan 1, 1938

SOUTHERN CALIFORNIA LOCAL .SECTION Executive Committee SEELEY W. MUDD, Chairman C. COLCOCK JONES, Vice-Chairman. FREDERICK J. H. MERRILL, Secretary-Treasurer, 631 Higgins Bldg., Los Angeles, Cal. RALPH ARNOLD A. B. CARPENTER The Southern California Section, held a dinner and meeting at. the Sierra; Madre Club, Los Angeles, on Friday evening, Sept. 28, 1915, at which 21 members and guests-were present. The Vice-Chairman, C. Colcock Jones; presided, in the absence of the Chairman. The amendment' to the By-Laws providing for the increase of the Executive Committee from five to seven members, having been formally presented at the annual meeting of June 18, 1915, and duly announced for consideration at this meeting, was voted on and unanimously adopted. Prof. Robert H. Richards of the Massachusetts Institute of Technology; made a short address on the subject of ore concentration. The paper on the Geology and Ore Deposits of Mojave, County, Arizona, prepared by F. C. Shrader, was presented to the meeting by the Secretary and was discussed by Allen Burris and Dr. L. D. Godshall. F. J. H. MERRILL, Secretary.

Jan 11, 1915

By Francis Otuonye

Rock fragmentation by blasting still remains the most common and cost-effective method of excavating hard rock in mining and tunneling operations. During blasting, the dynamic stresses induced by the detonation of the explosive, in addition to fragmenting the rock in the vicinity of the blast, may fracture the rock at considerable distances from the point of detonation of the explosive. The fractures can result in reduced mine safety, increased costs to support the opening, low productivity and perhaps high ore dilution. Besides the dynamic stresses produced in the rock, air blast overpressure pulses are generated and propagate through the network of underground mine openings. The waves, unable to spread out spherically or hemispherically like blast waves from surface blasting, are forced to propagate by reflection from the roof, ribs and floor down the drift. Blast wave focusing can occur and produce intense shock waves that could damage ventilation barriers such as cement block stoppings.

Jan 1, 1992