Search Documents

By J. P. Zannaras

Referring to the article by R. J. Charles and P. L. de Bruyn, let us assume that W = weight of glass bar; P = weight of hammer; e = total deformation; E = unit of deformation; K = potential stress energy; E = modulus of elasticity; L = length of the bar; 7, = coefficient of inertia; h = height, ft; V = velocity, fps; and a = cross section area. The portion of kinetic energy which is effective in producing stress energy in a fixed bar struck horizontally is given by the formula [ ]

Nov 1, 1956

By M. D. Banus, M. B. Bever, A. K. Jena

Measurements of the heat effects on addition of various solid phases of InSb to a solution calorimeter have confirmed the existence of a new high-pressure plzase InSbQII), which was jormed at 37 kbar and 623°K. The heats of formation of InSbQ), InSbfl), and InSb(111) have been measured and the heats of transjormation of InSb(1) to InSb(1l) and InSb(Iii) and of 'InSb(ll) to InSb(iiI) at atmospheric pressure and 78°K have been determined independently. Other thermodynamic properties of these phases, the phase boundary InSb(i)/InSb(ll), and the relative positions of the triple points are calculated. The pressure-Dolume term is shown to be more critical than the internal energy difference in making the phase InSbQ) less stable than InSb(II) at high pressures. Observations on partially transformed specimens suggest that the transformation of' metastable InSb (III) takes place in the two steps InSb(lll) — InSbQI) and InSbQI) — InSb(l). The compound InSb can exist as several phases depending on the temperature and pressure. The phase InSb(I), which is a semiconductor having the zinc-blende structure, transforms into the phase InSb(11) at a pressure of about 23 kbar and room temperature.'-3 The phase InSb(II) has the 6 tin structure,4-6 is metallic, and becomes a superconductor below 2.lok7 An orthorhombic phase of InSb has been reported to occur above a pressure of approximately 30 kbar at room temperature.' This phase is also a superconductor below about 3.4k9 The phase InSb(I1) is retained at atmospheric pressure if it is quenched to 78°K under pressure,6,7 but tends to transform at higher temperatures and does so explosively above approximately 210ok,7 A value of the heat of transformation of InSb(1) to InSb(II) at 210°K and atmospheric pressure has been reported.' A concurrent publication'0 reports evidence for a new solid phase InSb(III), which was formed by annealing InSb above 58 1°K at 37 kbar, above 560°K at 52 kbar, and above 473°K at 65 kbar. Specimens of InSb(II1) had a superconducting transition temperature of 4.lo ± 0.1oK. X-ray diffraction patterns also indicated the presence of a new phase. In this communication, thermodynamic properties of the phases InSb(I), InSb(II), and InSb(II1) are reported and discussed. The phase boundary InSb(I)/InSb(II) and the relative positions of the triple points are calculated. 1) EXPERIMENTAL 1.1) Preparation of Specimens. Specimens of the high-pressure phases of InSb were prepared in a belt-type high-pressure chamber by a tichnique described in detail elsewhere.'' Charges of 0.6 to 0.8 g of Cominco semiconductor grade InSb were used. The temperatures were measured with a chromel-alumel thermocouple, the hot junction of which was within 0.5 mm of the specimen. The specimens were heated under a pressure of 37 kbar for 1 hr at 723°K (which is well above the liquidus) and quenched to room temperature. One set was annealed at 523°K and another set at 623°K for 20 to 24 hr. These annealing temperatures were chosen because 523°K was below and 623°K was above the temperature of the transformation of InSb(II) to InSb(1Tl) at 37 kbar.10 The specimens were then cooled to 125°K by passing liquid nitrogen through the jacket of the belt die before the

Jan 1, 1968

By Arthur F. Wendt

Introduction.—In the year 1885, the writer signed a contract to take charge of the reopening and developing of the celebrated old mines of " El Cerro Rico de Potosi." Two years earlier, an Eng- . lish firm of engineers had made a very glowing report on the property. In the summer of 1885, telegrams arrived from the parties in charge of operations at the mountain, claiming the finding of one of the old veins, with an average richness of over 200 ounces to the ton. In the fall of 1886, the author first personally visited Potosi, but found neither the English report nor the telegram borne out by the facts. After an expenditure of over half a million of dollars and more than three years of continuons hard work, the writer succeeded in unwatering and developing one of the principal old veins of the mountain. This vein, called "Cotamitos," now yields ores of about 75 ounces to the ton, and the old historic mountains of Potosi may be said to have again fairly entered the list of silver-producers. The experience of the author, during his residence in Bolivia, and data obtained from Sr. Don F. Avelino Aramayo, form the basis of this description. POTOSI. Etymology of the Name.—The Quichuá (pronounced Keechna) Indians, known to North American students as the " Incas," although the word "inca" merely signifies ''king," or "chief," of the Quichuás, called the mountain "Sumac-orcko," or the beautiful mountain." Eighty-three years before the discovery of the mountain by the Spaniards, the inca, or king, Huaina Ccapac, travelling from Cantumarca to Calque-Porco, saw the mountain of Potosf and, admiring its grandeur and beauty, said that within its bowels there was, no doubt, much silver. He ordered his vassal* to work the mines. They, having carried their mining implements to the mountain, ascended it and were on the point of commencing work, when they heard a voice of thunder, which said: " Do not take

Jan 1, 1891

By J. B. Conway

RECENT studies of first-stage creep data have led to a special least-squares procedure for use in calculating the Andrade creep-equation constants. This procedure is easy to apply, uses only experimental data, and yields results which do not vary with the individual making the analysis. Taking logarithms of the Andrade equation I = lo(1 +ßl1/3)ekt leads to In l = In lo + In(1 + ßl1/3) + kt A residual can then be defined as the difference between the logarithm of an experimental length value and the logarithm of a calculated length value. Following the usual least-squares approach differentiation with respect to 10 and k of the expression for the sum of the squares of the residuals leads to two equations which cannot be solved directly for the three constants involved. However, values of ß can be assumed and corresponding values of lo and k can then be calculated. Then the sum of the squares of the residuals can be calculated. For a certain value of ß this sum will exhibit a minimum value to identify the least-squares values for ß, lo, and k. An illustration of the application of the above least-squares approach is obtained by employing the creep data for lead originally presented by Andrade' in the development of the one-third creep law. A plot of the sum of the squares of the residuals as a function of ß is shown in Fig. 1 along with the corresponding lo and k values. The minimum is seen to occur at ß = 0.0143 from which lo = 39.149 and k = 7.27 x 10-5. Based on these results the Andrade equation for these lead data is 1 = 39.149(1 + 0.0143 t1/3)e7.27 x 10-5t compared to the equation I = 39.13(1 + 0.01457/l/3)e6.95 X 10-5t developed by Andrade (calculation procedure not given but was probably a graphical solution). Calculating length values using the above equations and comparing with the experimental length values, residuals corresponding to the difference between experimental and calculated length values can be obtained. The sum of the squares of the residuals can then be calculated. For the case of the least-squares approach a value for this sum was found to be 2.37 x 10-3 compared to a value of 3.47 x 10" for the equation originally proposed by Andrade. In other words, while the constants proposed by Andrade provide an excellent fit for the lead data, a still better representation is afforded by applying the least-squares approach discussed above. A similar result was obtained for the lead data at 162oc.l The least-squares approach led to 1 = 9.866(1 + 0.0497 t1/3)el.011 x 10-2t compared to the equation I = 9.94(1 + 0.0433 l1/3)e1.06 X 10-2t given by Andrade. In this case, too, the sum of the squares of the residuals is slightly smaller for the equation based on the least-squares approach. It should be pointed out that a double trial and er-

Jan 1, 1965

By N. L. Hancox

Previous researchers have used the cutting and rejoining model to represent a porous body when attempting to place Archie's law on a theoretical basis and calculate rock permeabilities (F = Ø-m, where F = formation factor, = - porosity and m = a constant). In using the model, a porous solid is assumed to consist of sections with parallel sides containing straight. continuous pores of total porosity 4 (pore to total volume or, for a homogeneous body, pore to total area). The joining of pores at an interface between two sections is assumed to be random which results in a common pore area Ø2. This reduced area Ø2 is then taken as that area which limits electrical conduction or fluid flow in the body. Agreement between experimental results and results calculated using a model is not always good Because of this, various modifications of the model are presented — for instance, the random nature of the joining is questioned. Formation factor measurements on specially constructed porous specimens are described in this paper. it is concluded that the common pore area limits flow completely only if sections containing straight pores are very thin, and that, in most natural materials, the common pore area at an interface must be greater than that given by random joining. However, the model is still useful in permeability calculations, provided that the fractional area limiting flow is determined from formation factor measurements. INTRODUCTION Two important properties of porous media are permeability k, which describes the ease with which a fluid can flow through a porous medium, and formation factor F, defined as the ratio of the resistivity of a saturated specimen to the resistivity of the saturating liquid which describes the electrical properties of the saturated material. k is defined by Darcy's law,l k= µqL/P Ae . . . . . . . . . . . . . . . [1] where µ = liquid viscosity, q = flow rate, L = length of specimen, p = pressure across the specimen and = - the effective area over which flow occurs, F is given experimentally by Archie's law,2 F = Ø-m ,..............(2) where 4 is porosity defined as the pore to total volume or, for a homogeneous body, the pore to total area; and m lies between 1.3 for loose sand and 2 for cemented sand. Consider a porous body of total cross-sectional area A and length L, saturated with a liquid of resistivity R and with an effective area for conduction of Ae. Then, from the definition of F given previously, F=A/Ae , ................(3) or, from Eqs. 2 and 3, Ae = A Øm ..............(4) Thus, in any attempt to calculate k or F, some assumptions must be made concerning the pore structure of the body and a value derived for A,. To determine Ae, Childs and George3 and Wyllie and Gardner4 suggested an elementary statistical representation often referred to as the cutting and rejoining model of a porous body. The body is assumed to be composed of two or more parallel-sided sections of porosity 4, containing straight, continuous pores with a common pore area of Ø2 at an interface between two sections. The value is given by a random joining of the pores in either section. Two such sections,

Jan 1, 1969

Electrowinning U.S. 4,066,520 - Recovery of copper from copper sulfide ore. Finely divided ore concentrate is leached with moderately strong sulfurous acid to solubilize copper ions, the leach solution treated with calcium sulfite to reduce the copper ion concentration by forming copper-precipitate solids therein, the solids filtered off, and and the filter cake dewatered to obtain a slurry of copper-precipitate solids amenable to direct electrowinning of copper therefrom using a described electrolysis apparatus which utilizes high current flow with a minimum of mechanical agitation. R. C. Emmett, Jr., J. K. Dicksa. B. C. Wojcik and F. A. Baczek, assigned to Envirotech Corp. Jan. 3, 1978. 14 pp. (204- 108). Filed: 9- 1-76 (7 19,867).

Jan 1, 1979

By J. M. Sands

Describes important developments in, four counties, all of which brought in 40° oil. Indications are favorable for the future, although the daily production of the agate decreased 19,000 bbl. during the year 1923. THE state of Kansas had a daily average crude-oil production of about 87,000 bbl. at the beginning of the year. This showed a steady but consistent decline during the 12 months, so that the daily average production at the end of the year was slightly over 68,000 barrels. GREENWOOD COUNTY THE most active development in Kansas during the year was in Green-. wood County, in a line from near Sallyards in T 25-R 9 to east of Madison in T 22-R, 11. The main part of. this development has been in a succession of pools beginning at the south with the Polhamus pool in 34-24-9 and 3 and 4-25-9; Thrall pool in 28, 29, 32 and 33-23-10; Burkett pool in. 13, 23, 24 and 26-23-10; Seeley and Wick pool in 22, 27, 28, 32 and 33-22-11 and 5, 6, 7, and 8-23-11; Frohm pool in 11, 14 and 15-22-11; Madison pool in 31 and 32-21-12 and 6, 22, 12 and 1-22-11. Some of these pools, have two or more sands, locally called Bartlesville and Burgess Sands. They range in. depth from 1850 ft. near Madison to 2450 ft. near Sallyards, the general dip being to the west. The thickness of these sands runs from 20 to 100 ft., the initial production of the wells being 50 to 1000 bbl. of 40-gravity oil or better.

Jan 3, 1924

PAST AND PRESENT CHAIRMEN OF DIVISIONS Institute of Metals Iron and Steel Mineral Industry Industrial Minerals Year Division Petroleum Division Division Coal Division Education Division Division 1918 W. M. CORSET 1919 " 1920 W. H. BASSETT 1921 " 1922 W. B. PRICE RALPH ARNOLD 1923 E. DEGOLYER 1924 G. B. ELLIOTT 1925 F. JULIUS FOHS 1926 P. D. MERICA 1927 11 JOHN. M. LOVEJOY 1928 S. SKOWRONSKI A. W. AMBROSE RALPH H. SWEETSER ' 1929 " J. B. UMPLEHY G. B. WATERHOUSE 1930 ZAY JEFFRIES C. V. MILLIKAN W. J. MACKENZIE HOWARD N. EAVENSON 1931 SAM TOUR C. E. BEECHER F. M. BECKET 1932 C. H. MATHEWSON EARL OLIVER F. N. SPELLER THOMAS G. FEAR C. H. FULTON 1933 T. S. FULLER W. E. WRATHER JOHN JOHNSTON ELI T. CONNOR " 1934 J. L. CHRISTIE H. D. WILDE, JR. L. F. REINARTZ " T. T. READ 1935 W. M. PEIRCE HARRY H. POWER A. B. KINZEL JOHN T. RYAN SAMUEL H. DOLBEAR 1936 E. H. DIX, JR. HALLAN N. MARSH C. E. WILLIAMS EUGENE MCAULIFFE WILLIAM B. PLANK OLIVER BOWLES 1937 A. J. PHILLIPS M. ALBERTSON FRANCIS B. FOLEY J. B. MORROW " CHESTER A. FULTON 1938 R. F. MEHL G. B. CORLESS J. T. MACKENZIE PAUL WEIR FRANCIS A.THOMSON J. R. THOENEN 1939 R. H. LEACH W. H. GETS J. HUNTER NEAD C. A. GIBBONS " M. M. LEIGHTON 1940 E. M. Wise T. V. MOORE F. T. SISCO C. E. LA WALL W. R. CHEDSEY W. M. WEIGEL 1941 D. K. CRAMPTON E. A. STEPHENSON C. H. HERTY, JR. JULIAN E. TOBEY " PAUL M. TYLER 1942 CARL E. SWARTZ HARRY P. STOLZ E. C. SMITH NEWELL G. ALFORD A. F. GREAVES-WALKER B. L. MILLER

Jan 1, 1943

The following is an incomplete list of members and guests who called at Institute headquarters during. the period Mar. 10, 1919,. to Apr. 10, 1919. F. T. Agthe, Hannibal, Mo. Jay Lonergan,. Denver, Colo. W. F. Almy, Canada. R. R. London, Cebu, P. I. P. G. Bandy, Mexico. W. D. Mainwaring, Philadelphia, Pa. H. R. Bank, Humboldt, Ariz. _ W. G. Mitchell, Montreal, Can. Alan M. Bateman, New Haven, Conn. Francis Nicholson, Joplin, Mo. C. A. Brooks, Lead, S. Dak: C. H. Palmer, Los Angeles, Calif. Louis J. Brunel, Oakland, Calif. D. A. Powell, Columbus, Ohio. W. Burns, Sante Fe, N. M. W. H. Reber, Dallas, Tex. J. B. Carlock, Major, 1st Gas Regt. Capt. J. B. Richards, Spokane, Wash. Louis S. Cates, Hayden, Ariz. T. C. Roberts, E. Orange, N. J. W. M. Corse, Mansfield, Ohio Max Roesler, Washington, D. C. E. 0. Daue, Philadelphia, Pa. C. 0. Sanford, Los-Angeles, Calif. John Davenport, W. Norfolk, Va. Gustave Sessinghaus, Denver, Colo. James T. Dixon, London, England, . E. H. Shriver, Milford Center, Ohio. S. K. Dahl, Messina, Transvaal, S. Af. H. M. Spoor. W. G. Eberhardt, Tucson, Ariz. W. H. Staver, New York. H. S. Emlaw, Grant Haven, Mich. D. B. Sterrett, Washington, D. C. I. W. Farrand, Camp Merritt. W. G. Swart, Duluth, Minn. Oscar Gotsch, Jr., St. Louis, Mo. A. W. Stickney, London, England. James 0. Greenan, Oakland, Calif. E. C. Templeton, Downey, Calif. Gilbert Hart, Philadelphia, Pa. . . R. T. Walker, Pioche, Nev. K. L. Hsueh, China. A. T. Ward, Bellefonte, Pa. Zay Jeffries, Cleveland, Ohio. Joel H. Watkins, Washington, D. C. R. W. Kern, Verde, Ariz. J. Wertheimer, Cleveland, Ohio. H. D..Kinney, Easton, Pa. C. R. Wilfley, Ouray, Colo. E. L. Lasier, Washington, D. C. J. P. Wood, Engrs., U. S. A. Carl Zapffe, Brainerd, Minn. Leland D. Adams has left the employ of the Weedon Mining Co., Ltd., at Montreal, Quebec, and is going to Oakland, Calif., where his address will be 1180 Mandana Boulevard.

Jan 5, 1919

PAST AND PRESENT CHAIRMEN OF DIVISIONS Institute of Metals Iron and Steel Mineral Industry Industrial Minerals Year Division Petroleum Division Division Coal Division Education Division Division 1918 W. M. CORSET 1919 " 1920 W. H. BASSETT 1921 " 1922 W. B. PRICE RALPH ARNOLD 1923 E. DEGOLYER 1924 G. B. ELLIOTT 1925 F. JULIUS FOHS 1926 P. D. MERICA 1927 11 JOHN. M. LOVEJOY 1928 S. SKOWRONSKI A. W. AMBROSE RALPH H. SWEETSER ' 1929 " J. B. UMPLEHY G. B. WATERHOUSE 1930 ZAY JEFFRIES C. V. MILLIKAN W. J. MACKENZIE HOWARD N. EAVENSON 1931 SAM TOUR C. E. BEECHER F. M. BECKET 1932 C. H. MATHEWSON EARL OLIVER F. N. SPELLER THOMAS G. FEAR C. H. FULTON 1933 T. S. FULLER W. E. WRATHER JOHN JOHNSTON ELI T. CONNOR " 1934 J. L. CHRISTIE H. D. WILDE, JR. L. F. REINARTZ " T. T. READ 1935 W. M. PEIRCE HARRY H. POWER A. B. KINZEL JOHN T. RYAN SAMUEL H. DOLBEAR 1936 E. H. DIX, JR. HALLAN N. MARSH C. E. WILLIAMS EUGENE MCAULIFFE WILLIAM B. PLANK OLIVER BOWLES 1937 A. J. PHILLIPS M. ALBERTSON FRANCIS B. FOLEY J. B. MORROW " CHESTER A. FULTON 1938 R. F. MEHL G. B. CORLESS J. T. MACKENZIE PAUL WEIR FRANCIS A.THOMSON J. R. THOENEN 1939 R. H. LEACH W. H. GETS J. HUNTER NEAD C. A. GIBBONS " M. M. LEIGHTON 1940 E. M. Wise T. V. MOORE F. T. SISCO C. E. LA WALL W. R. CHEDSEY W. M. WEIGEL 1941 D. K. CRAMPTON E. A. STEPHENSON C. H. HERTY, JR. JULIAN E. TOBEY " PAUL M. TYLER 1942 CARL E. SWARTZ HARRY P. STOLZ E. C. SMITH NEWELL G. ALFORD A. F. GREAVES-WALKER B. L. MILLER

Jan 1, 1942

Agnico-Eagle Mines Ltd. comprises a Gold Division at Joutel, Quebec, and a Silver Division at Cobalt, Ontario. In 1979 the Silver Division milled 41,700 mt (46,000 st) of ore at a recovered grade of 139 g per mt (4.06 oz per st) for a production of 5,816 kg (187,000 oz) of silver. The 100 -year -old mining, camp of Cobalt has long been noted for its high-grade silver ores, and now seems to be on the threshold of being revived with several companies operating in the area. In 1979, the Gold Division milled at the rate of 27,200 mt per month (30,000 st) and processed 333,000 mt (367,000 st) at a grade of 6.58 g per mt (0.192 oz per st) with a mill recovery of 91.670 to produce 2,013 kg (64,700 oz) of gold. The average total cost per ton milled was $22.10 per mt ($20.05 per st) which was $3.66 per g ($1 13.90 per 0s). These figures make Agnico-Eagle one of the lowest cost producers in North America. Gold occurrence in the Joutel ore is fine-grained and contained within sulfide facies composed mainly of pyrite with minor pyrrhotite. Two underground mining methods are employed with long hole stoping accounting for about 75% of the ore mined and shrinkage stoping the remainder. Ore from underground is hoisted into a 545 mt (600 st) coarse ore bin from where it is conveyed to a 45 mt (50 st) surge bin ahead of the 10-51 Hydrocone crusher. Crushed ore is then screened to make a 13 mm (112 in.) product with the oversize being recrushed in a 7-60 Hydrocone. Mill feed is conveyed to two 900 mt (1,000 st) fine ore bins. The Hydrocones were installed as part of a new crushing plant in March of 1980 and have contributed substantially to an increase in mill capacity. Space has been left to install a third crusher in the future. The fine ore bins discharge to a 2.75 m by 3.66 m (9 ft by 12 ft) rod mill, followed by a 3. 7 m by 5.5 m (12 ft by 18 ft) ball mill in closed circuit with a Krebs 380 mm (15 in.) cyclone to produce a 7070 minus 37 micron (400 mesh) .flotation feed. This pulp is first treated in a 34 cu m (1, 200 cu ft) Maxwell flotation cell and then in an additional twelve 2.8 cu m (100 cu ft) cells. Combined flotation concentrates are reground to 9070 minus 37 microns (400 mesh) in a 1.8 m by 4.9 m (6 ft by 16 ft) ball mill in closed circuit with a single Krebs 254 mrn (10 in.) cyclone. Flotation tailings are sent to the tailings dam. Reground concentrates are then aerated with lime to a single Pachuca and thickened in a 16.75 m (55 ft) diameter thickener with the addition of diesel fuel to render any activated graphite inert to adsorption of

Jan 1, 1981

By J. Kucera, J. Vreštál

DIFFERENT authors1 ' have been engaged in meas-uring the vapor pressure of pure cobalt. The results of their measurements satisfy the expected temperature dependence of vapor pressure and are in mutual agreement, with the exception of the results by De Dyk Man and ~esmejanov.~ The latter authors, by using the effusion method, have achieved considerably higher values than other workers. By using the isotope exchange method they obtained much lower values than other authors. The determination of thermodynamic functions of the binary Ni-Co system was carried out, as far as we know, only by De Dyk Man and Nesmejanov.4 This determination was based on extremely low values of vapor pressure over pure cobalt obtained by the isotope exchange method. Therefore we considered it useful to repeat these measurements. Furthermore, the reliable values of thermodynamic functions should complement the migration characteristics, the inner magnetic field data obtained by Miissbauer effect measurements, specific heat data, and the K effect and positron annihilation characteristics that have been achieved for the Ni-Co system in the Institute of Metallurgy of the Czechoslovak Academy of Sciences in Brno.5-9 The measurements in this paper were performed by the isotope exchange method. In this method, as has been shown by analysis,10-'3 the vaporization rate, w, can be calculated from the relation w = k/1oSw [1] i0Sw) [1] where L, is the activity per unit mass of the source, S is the area of evaporation, k is the tangent at the point t = 0 to the curve giving the radioactivity de-pendence of the target vs annealing time, t, and wis the probability for the tracer atom condensation on the target surface. The value for cc. can be obtained from the equation w = a + 2P(l-a) [2] where P is Clausing's coefficient and a is the condensation coefficient. In the present work the cylinder shaped containers for annealing the samples were used, characterized by the ratio 1:d = 1.06. Here 1 is the length and d the diameter of the container. For this ratio P = 0.514 and w =0.5, and w is independent of the condensation coefficient. The vaporization rate is related to the vapor pressure p by the relation where R is the gas constant, T is the absolute temperature, and M is the molecular weight of the component investigated. Measurements of the vapor pressure of the i component over the pure metal, p!, and the alloy, pi, at the given temperature and composition enable one to calculate the thermodynamic activity of this component from the equation ai=pi/pi [4] is and the activity coefficient ri=ai/xi [5] xi where xi is the molar fraction of the investigated alloy component. EXPERIMENTAL Evaporization rate measurements were carried out with pure cobalt and eight different Ni-Co alloys, which were kindly delivered by the Centre National de Recherches Me'tallurgiques Liege, Belgium. The composition of the alloys is given in Table I. The cobalt used in these alloys contained the following impurities: 0.016 wt pct Fe, 0.014 wt pct Cu, 0.01 wt pct Mn. Other elements were present in much lower concentrations. From the melts, samples in the form of small cylinders of 12 mm in diam were ma-chined. The thickness of the targets and sources was 2.5 and 1.2 mm, respectively. The lower thickness of the sources was chosen to make their over-all ac-tivity as low as possible. Sources were activated in

Jan 1, 1970

By A. U. Seybolt

The pressure-temperature relations required to maintain the existence of Si3N4 in silicon-iron of 0.44-11.7 pet Si have been partially explored. The critical data obtained have allowed the calculation of some thermodynamic quantities, and have shown evidence of an order-disorder two-phase field extending at 800°C from about l pet to 5.5 pet Si. THE presence of silicon nitride in electrical sheet, nominally about 3 1/4 pet silicon, balance iron, has been described by several authors'" but there has been some discrepancy among them regarding the identity of the nitride. Also, little has been reported on the quantitative thermodynamic prop- erties. In the work to be reported here, the nitride has been found to be more stable than described by Corney and Turkdogan." Several silicon nitrides have been described in the past, including SiN, Si3N4 and Si2N4 (see, for example, Abegg6 and Pascal7). However, the literature on nitrides other than Si,N, is all very old. No recent investigators using the more powerful tools available today have reported the presence of any nitride other than S3,N4. W. B. Hicke and L. R. Brantley8 in 1930 determined the dissociation pressure of Si3N4 which they made by reacting nitrogen

Jan 1, 1959

US 4,185,078-In the recovery of rhenium values from an aqueous sodium molybdate solution contained in the hydrometallurgical processing of roasted molybdenite, improved results are realized by using a described extractant consisting of a quaternary ammonium compound and benzene or other highly aromatic solvent which dissolves a quaternary ammonium-rhenium complex Essentially all rhenium is recovered from the solution and the extractant can be regenerated and recycled. This patent is a continuation-in-part of US Patent No. 4,049,771, dated Sept. 20, 1977. L R. Quatrini and M.B MacInnis, assigned to GTE Sylvania Inc. Jan 22, 1980. 6 pp (423-49). Flied. 7-19-78 (926,167).

Jan 1, 1982

Members whose deaths were reported from Apr. 5, 1920, to Apr. 9, 1921. Elected Died 1916 ALLAN, FERGUS L 1920 1916 ATKINSON, CHESTER 1921 1920 BARBERENA, RAUL R 1920 1918 BARKER, F. L 1920 1914 BELL, D. A. S 1920 1920 BREWSTER, GEORGE AUGUSTUS 1920 1917 BRIGHAM, EDMUND D 1921 1915 CARROLL, D. J 1920 1897 CHAPMAN, ROBERT H 1920 1919 COOPER, W. G 1920 1918 CRITCHLOW, EDWARD B 1920 1917 CURTIS, WILLIAM L 1920 1893 DARSIE, JAMES 1920 1892 DELANO, WARREN 1920 1877 DEWEY, FREDERIC P 1921 1917 ENEBO, BENJAMIN A 1920 1896 FAWCETT, JAMES H 1920 1906 FRASER, A LEXANDER J . 1920 1889 GARLICHS, HERMAN 1921 1893 GILLET, LORENZO M 1920 1886 HALDEMAN, HORACE L 1920 1914 HALL, HARRY E 1919 1905 CHART, C. R 1920 1906 HART, PHILIP E 1920 1877 HARTRANFT, SAMUEL S 1921 1914 HICKMAN, E C 1920 1919 || INMAN, WILLIAM ELLIOTT 1921 1920 JETER, J. TINSLEY 1920 1918 JOHNSON, CHARLES W 1920 1916 JOHNSON, FRANK E 1920 1913 KING, FREDERICK G 1921 1887 KNAPP, GEORGE F 1920 1902 LAMB, RICHARD 1920 1880 LANE, J. S 1920 1920 LECKIE, WILLIAM 1920 1887 LEVAT, DAVID 1921 1882 LAWRENCE, BENJAMIN B 1918 1916 LEYNER, J GEORGE 1920 1871 LYMAN, BENJAMIN S 1920 1903 MCCHRYSTAL, JOHN H1920

Jan 1, 1923

By Dilip K. Das, Douglas T. Pitman

ONE of the major uses of barium in metallic form is as a getter material in vacuum tubes. Because of the high chemical reactivity of the metal, Ba-Al alloys are extensively used. Numerous methods for the preparation of Ba-Al alloys have been published, a few of which1-4 are cited here. Most of these methods were found to be quite elaborate, involving the reduction of BaO, and not too well adapted for the close control of the final composition of small amounts of alloys prepared for laboratory use. A simple laboratory method for the preparation of Ba-A1 alloys in small batches starting from pure metals was devised, so that it was possible to control the desired compositions to within 1 pct. The pertinent features of the alloy system Ba-Al5 are 1) an intermediate compound BaAl, with the melting point of 1050°C, and 2) a eutectic between aluminum and BaAl4 at 98 pct Al. The accompanying sketch shows the experimental arrangement for the preparation of the alloys. Weighed amounts of aluminum and barium were placed in an alumina and a stainless steel crucible, respectively. According to the supplier's specification, the purity of the metals used in the alloys is as follows: a) aluminum rods—99.9 pct Al, and b) barium rods—99.5 pct Ba. The stainless steel crucible, tapered at the bottom and having a 1/16 in. diam hole, rested on top of the alumina crucible. The assembly was placed inside a graphite sleeve which rested on a refractory platform. The platform moved the assembly up and down through the field of a radio frequency coil. A glass bell jar was placed between the crucible assembly and the radio frequency coil to maintain a steady flow of helium around the melt. A small window was cut out on the wall of the alumina crucible to observe the progress of the re- action and to record the temperature with an optical pyrometer. The platform was first raised high enough to move the barium out of the radio frequency coil field in order to allow only the aluminum to melt. The assembly was then lowered so that the barium began to melt and flow out through the small orifice into the molten aluminum. In order to keep the violence of the exothermic reaction under control, the rate of flow of barium was carefully regulated by raising or lowering the crucible assembly. All the samples prepared by this technique were examined by a Norelco X-ray diffractometer using CuKa radiation, The diffraction specimens were prepared by placing the finely powdered samples in flat specimen holders. The Ba-Al alloys prepared with a high barium content were found to consist mainly of BaAl4. The structure of BaAl4 has previously been reported by Alberti and Andress.8 They found that BaAl4 was body-centered-tetragonal with an a0 = b0 = 4.530Å and c0 = 11.14Å. An alloy whose composition was found by chemical analysis to be almost 100 pct BaA1, was used to determine the relative intensities. The d-spacings were obtained from the same alloy to which a small amount of tungsten had been added as a calibrating material. Accurate values for a, and c, were calculated according to the method proposed by Taylor and Floyd.' The calculated values are: a, = b, = 4.566Å and c0 = 11.250Å. The measured d-values for BaAl4 are shown in Table I along with relative peak intensities above background and hkl indices. Acknowledgment The authors are grateful to L. J. Cronin, the head of the Techniques Dept., for suggesting the problem and for his constant interest. References 1Froges and Camargue: German Patent No. 809107, 1951. French Patent No. 935324, 1949. 2E. Bonnier: Annales de physique, 1953, vol. 8, pp. 259-312. 3M. Orman and E. Zemhela: Prac Institute of Metals; 1952, vol. 4, pp. 437-445. 4E. Fujita and H. Yokomizo: Reports Gov. Chemical Industrial Research Institute, Tokyo, 1952, vol. 47, pp. 291-297. 5E. Alberti: Ztsch. fur Metallkunde, 1934, vol. 26, p. 6. 6E Alberti and K. R. Andress: Ztsch. fur Metallkunde, 1935, vol. 27, p. 126. 7 A. Tnslor and R. W. Floyd: Acta Crystallographica, 1950, vol. 3, p. 285.

Jan 1, 1958

The following is an incomplete list of members and guests who called at Institute headquarters during the period Jan. 10, 1918 to Feb. 10, 1919. Walter F. E. Barcus. Lt. C. K. McDonald, U. S. N. R. F. Capt. D. H. Bradley, Jr. Major John DeN. Macomb, Bayhead, N. J. Melvis Buigger. - Samuel Melitzer, New York City. Eugene Coste, Calgary, Can. T. C. Merriman, New Haven, Conn. C. W. Cromwell, Warren, Ariz. Wm. J. Millard, Tulsa, Okla. E. O. Daue. Benj. L. Miller, Bethlehem, Pa. Capt. H. W. Edmondson. S. B. Patterson, Jr., Allentown, Pa. E. W. Engelmann, Hayden, Ariz. Lynn L. Pomeroy, New York City. C. Mason Farnham. W. E. Pomeroy, New York City. Lt. C. W. Frith, Salt Lake City, Utah. G. M. Ponton, Ottawa, Ont. John T. Fuller, Honesdale, Pa. Wallace E. Pratt, Ft. Worth, Tex. Walter A. Funk, Idaho Sp., Colo. Harold L. Rau, Milwaukee, Wis. Major W. R. Grunow, New York, N..Y. Lt. E. J. Ristedt, Camp Merritt. A. W. Hackwood, Butte, Mont. George M. Ryall, Los Angeles, Cal. Lt. Nathaniel Herz, New Haven, Conn. D. B. Scott, Mogollon, N. M. Ralph T. Hirsh, New York City., W. H. Staver. O. P. Hood, Washington, D. C. Douglas B. Sterrett, Washington, D. C. E. B. Hopkins, Houston, Tex. J. A. Stewart, Minneapolis, Minn. Hugh C. Ingle, Pensacola, Fla. R. H. Summer, Wilmington, Del. Capt. Wm. F. Jahn. W. G. Swart, Duluth, Minn. Roswell H. -Johnson, Pittsburgh, Pa. Kirby Thomas, New York City. Jesse L. Jones, Pittsburgh. Pa. Capt. H. D. Trounce, San Diego, Cal. Edgar Kidwell, Berkeley, Cal. L. Unger, New York City. .D. H. Ladd, Detroit, Mich. George F. Vivian, Butte, Mont. Raymond B. Ladoo, Cambridge, Mass. R. A. Walter, Reading, Pa. W. H. Landers. Lt. R. G. Wayland, Chehalis, Wash. David Lasner, Elizabeth, N. J. R. J. White, Wallace, Idaho. J. M. Lilligren. J. S. Wroth, Albuquerque, N. M. Lt. Wm. J. Linn, Chicago, Ill. Herbert Hoover, General Pershing, Ambassador William G. Sharp and Admiral William S. Benson were speakers to-day at the annual luncheon in honor of Washington's Birthday, given by the American Club of Paris at the Palais D'Orsay.

Jan 3, 1919

The Committee on Technical Nomenclature, of which John T. Faig, Professor of Mechanical Engineering at the University of Cincinnati, is Chairman, appointed by the Society for the Promotion of Engineering Education, has recently issued a report advocating uniformity in the use of symbols to designate engineering and mathematical terms: The selection of the symbols was based upon a canvas of a considerable number of engineers, editors of engineering papers, and professors of engineering throughout the United States. The list, as finally accepted by the Committee and recommended for universal adoption, is as follows: Concept Symbol I Concept Symbol Acceleration due to gravity 'g Length L Acceleration, linear a Mass m Area A Modulus of section Z Breadth b Modulus of elasticity, Young's... E Center of rotation 0 Moment of force M Coefficients and constants C, K Moment of inertia, polar J Deflection of beam y Moment of inertia, rectangular.. I Depth : d Quantity of liquid flowing Q Diameter D . Radius r Distance passed over s Radius of gyration k Distance of extreme fiber from Reactions R neutral aids C Revolutions per unit of time.... N Eccentricity of application of load e Stress, unit S Efficiency (hydr., mech., vol.)...er,.em, e9 Time t Force F Torque T Friction, coefficient of f Velocity, angular :. W Head H 'Velocity, linear V Height h Volume V Horsepower : Hp Weight W Hydraulic radius Re Previous lists of symbols have not secured wide acceptance in, this country; some that have been proposed by prominent writers are familiar to very few engineers. The above list is presented in the hope that it will assist in the evolution of a standard list. It is short; it contains no Greek letters; it is mnemonic to a considerable degree, though not by

Jan 1, 1918

Discussion of the paper of Frank H. Kneeland, Safeguarding the Use of Mining Machinery. By B. F. Tillson and Arthur Williams. 1073 Discussion of the paper of Howard N. Eavenson, Safety Methods and Organization of United States Coal & Coke Co. By William H. Grady, Thomas W. Dawson, C. W. Goodale, J. Parke Charming, B. F. Tillson, George S. Rice, Arthur Hovey Storrs, Harry H. Stoek, Lawson Blenkinsopp, Arthur Williams, and Howard N. Eavenson. 1075 Discussion of the paper of J. Parke Channing, Enlarging the Worth of the Worker and the Perspective of the Employer. By Fred H. Rindge, Jr., S. A. Taylor, Elmer L. Corthell, and Philip W. Henry. . 1095 Discussion of the paper of Walther Mathesius, High Blast Heats in Mesaba Practice. By Joseph W. Richards, W. A. Forbes, J. E. Johnson, Jr., H. P. Howland, and Walther Mathesius. . 1100 Discussion of the paper of W. R. Shinier, Effect of Finishing Temperatures of Rails on Their Physical Properties and Microstructure. By William R. Webster, Henry M. Howe, A. A. Stevenson, G. K. Burgess, and Samuel L. Hoyt . 1107 Discussion of the paper of George K. Burgess and Sir Robert A. Hadfield, Sound Steel Ingots and Rails. By Albert Sauveur, Henry M. Howe, Henry D. Hibbard, Joseph W. Richards, F. W. Wood, and George K. Burgess. . 1112 Discussion of the paper of Henry M. Howe and Arthur G. Levy, Are the Deformation Lines in Manganese Steel Twins or Slip Bands? By J. E. Stead 1116 Discussion of the paper of F. C. Langenberg and R. G. Webber, Structures and Hysteresis Loss in Medium-Carbon Steel. By Henry M. Howe. . . 1117 Discussion of the paper of Charles H. MacDowell, German and Other Sources of Potash Supply. By George S. Rice, Charles H. MacDowell, and V.C. Grubnau . . 1118 Discussion of the paper of Joel H. Watkins, White-Burning Clays of the Southern Appalachian States. By H. Ries 1120

Jan 5, 1915

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, Jr., Chairman EDGAR RICKARD, Vice-Chairman D. M. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer JOHN V. N. DORR. LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge,Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY. Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. 0. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD Puget Sound Meets second Saturday of each month SIMON H. ASH, Chairman I. F. LAUCKS, Vice-Chairman CHARLES SIMENSTAD, Secretary-Treasurer, 425 Lyon Bldg., Seattle, Wash. GLENVILLE A. COLLINS JOHN N. POTT

Jan 10, 1917