Search Documents

By AIME AIME

METALLIC corrosion, which results from the chemical affinity of different metals for non- metallic elements, should be considered from both the kinetic and static viewpoints. From the stand- point of statics the metals may be arranged in the order of their affinity for oxygen, chlorine or any other acid- forming element. They may also be arranged in the order of the magnitude of the heat of combination of their corresponding compounds. It is misleading to talk about some metals as "noble," because these relations are all relative; and the order varies for oxygen, chlorine or whatever the element may be. A third way to arrange the metals is by their solution pressures. These three methods indicate that one metal is better under one set of conditions, but not so good under other conditions. Considering the problem from the standpoint of kinetics, the thing which saves most metals is what may be called the sluggishness of reactions. Using organic substances as an example, we know they will all oxidize, but fortunately they do so rather slowly. An increase in temperature always means an increase in the reaction rate, and preventing corrosion at high temperatures is a greater problem than at low temperatures. A second consideration is to avoid all sub- stances which might provoke catalytic action, and as it is generally impossible to foresee what substances might do this, the thing is to avoid all substances other than the main constituents of the alloys. A third consideration is to avoid local electrolytic action, which again indicates the advisability of avoiding the contact of differing substances.

Jan 1, 1926

By S. G. Epstein

Using the capillary-reservoir technique, electromi-gvation rates of cadmium and indium in liquid bismuth were measured at several temperatures. The electric mobility of cadmium Jrom 305° to 535°C and indium from 310° to 595°C can be expressed as a function of temperature by the equations UIn = 1.52 x 10-3 exp sq caz per v-sec Migraion of both solutes was cathode-divected at a rate rnore than four tiMes tHAt previously found for siluer in liquid bisnmth. The electric mobilities of cadmium and indiulrz in liquid bismuth at 500° C are nearly identical with their respective mobilities in mercury at room temperature. AS part of a systematic study of the variables which are considered to control electromigration in liquid metals, the electromigration rates of cadmium and indium in liquid bismuth have been measured. Mass transport properties of silver in liquid bismuth have been reported previously,&apos; and measurements of tin and antimony in liquid bismuth are forthcoming. Comparisons will be made with literature values for these same solutes in mercury.2&apos;3 This series of solutes was selected to determine the effect of the solute valence on its electromigration. Silver, cadmium, indium, tin, and antimony have nearly equal atomic masses but have chemical valences ranging from +1 to +5. They are all fairly soluble in bismuth above 300°C and all have radioactive isotopes, which are an aid in making analyses. EXPERIMENTAL TECHNIQUE Electromigration of cadmium and indium in liquid bismuth was measured by the modified capillary-reservoir technique previously described.&apos; In this method irradiated cadmium or indium is added to bismuth to form alloys containing about 1 wt pct solute (<2 at. pct solute). Several quartz or Pyrex capillaries: 1 mm ID and 5 cm long, vertically oriented, are simultaneously filled in the reservoir of the liquid alloy. A direct current is passed through two of the capillaries, which contain tungsten electrodes sealed in the upper end. The other capillaries sample the reservoir during the experiment. After a measured time interval the capillaries are removed from the reservoir and rapidly cooled. The glass is then broken away from the solidi- fied alloy, which is then weighed, dissolved in acid, and analyzed for solute content by chemical and radiochem-ical techniques. An electric mobility (velocity per unit field) can be calculated from the amount of solute entering or leaving each capillary by the simplified expression1 in which Ui is the electric mobility of the solute, ?mi the solute weight change, Ci the solute concentration of the reservoir, I the current, p the alloy resistivity, and l the duration of the experiment. This expression is valid as long as the experiment is terminated before a concentration gradient develops across the capillary orifice. Earlier experiments showed that the concentration gradient formed initially at the electrode changes with time and eventually reaches the orifice, due to back-diffusion. This condition produces a solute exchange between capillary and reservoir by diffusion or convection, opposing the electromigration, which results in a lower measured value for the electric mobility. To determine if the concentration gradient had reached the orifice, the capillaries used in some of the experiments were sectioned at 1-cm intervals and the solute content of the alloy from each section was radiochemically determined. A typical concentration profile for an experiment with indium in bismuth is shown in Fig. 1; cadmium in bismuth showed similar behavior. As illustrated in the graph, very little back-diffusion has occurred in the capillary containing the cathode, since the concentration gradient is confined to the upper 1 cm of the capillary. In the capillary containing the anode, however, the concentration gradient is much broader, extending nearly to the orifice, even though the net change in solute concentration is nearlv the same in both capillaries. Since cadmium and indium probably lower the density of bismuth when alloyed, depletion of the solute from the alloy adjacent to the anode would increase the density of the liquid in the uppermost region of the capillary. This would give rise to convective mixing within the capillary, causing the broadened concentration gradient. Conversely, the alloy adjacent to the cathode should have a reduced density as the solute concentration is increased by migration, explaining the "normal" concentration profiles found in these capillaries. This disparity was not found for electromigration of silver in bismuth. Both metals have similar densities at the operating temperatures, and nearly symmetrical concentration profiles were found in the two capillaries of each exueriment. This density effect was also apparently encountered when an attempt was made to measure diffusion coefficients for indium in liquid bismuth by the same technique which was successfully used to measure diffusion of silver in bismuth.&apos; Capillaries 1 mm ID and 2 cm

Jan 1, 1968

By A. U. Seybolt

In part 111&apos; of this series it was shown that during the selective oxidation of a 3 1/4 pct Si-Fe alloy in damp hydrogen, only silica, (observed at room temperature) as low cristobalite or low tridy-mite or both, was formed as an oxidation product. In some in- „ stances where the film was fairly thin (probably well under 100A) there was some suggestion of an amorphous form of SiO2. The present investigation of oxidation rate showed that the selective oxidation of silicon-iron can be rather complicated, and apparently impossible to rationalize in an unequivocal manner. In some temperature regions, notably near 800" and 1000°C, the data seem to obey the familiar parabolic rate law. However, at intermediate temperatures complications were noted, some of which are possibly due to the order-disorder reaction in the silicon-iron solid solution. IN an earlier report&apos; it was shown that during the oxidation of 3 1/4 pct Si-Fe alloys in H2O-H2 atmospheres only silica films were formed in the temperature range from 400° to 1000°C in hydrogen nearly saturated with water at room temperatures, or at dew points as low as -45°C. In the work to be reported here, some observations are made on the rate of oxide film formation. As in the earlier investigation, electron diffraction patterns generally showed either low tridymite or low cristobalite or both, except for some very thin films. These sometimes showed diffuse rings, presumably due to a very small crystallite size, or in a few cases, diffuse bands probably caused by an amorphous film. EXPERIMENTAL PROCEDURE Vacuum-melted silicon iron made of high-purity materials was rolled into strips 0.014 in. thick, and cut into samples 1/2 in. wide by 1 in. long. Chemical analysis showed 3.2 pct Si and 0.002 pct C. All samples were surface abraded with 600-grit paper, were solvent cleaned, and then placed in an paper,apparatus containing a "Gulbransen type"2 micro-balance. Here the gain in weight of the samples of about 5 sq cm area could be followed as a function of time during the oxidation caused by the water in atmospheres of various controlled water-hydrogen ratios. The water-hydrogen ratios can most easily be described as varying from a dew point of 0°C (PH2O-p^2 = 6.2 x 10-3 , to K (P j -40°C (PH2O/PH^= 1.3 X 10-* Most of the experiments were conducted at the 0°C dew-point atmosphere because drier atmospheres caused so little gain in weight that the accuracy of measurement was poor. Because of this, only the data obtained at PH2O,/P,,,= 6.2 x X3 will be reported. The temperature range extended from 800" to 1000°C; and most of the oxidation runs lasted for about 24 hr. The reproducibility of any reading was about ± 1 ?, but the sensitivity of the balance was about 0.2 ?. The atmosphere, flowing at 200 cm per-min, was preheated to the furnace temperature before contacting the specimen. While the gas flow caused a measurable lift on the sample, it was ordinarily sufficiently constant so that it was not an appreciable source of error. X-ray and electron diffraction checks of the samples before and after oxidation showed no evidence of preferred orientation, either on the metal samples or on the silica films formed. EXPERIMENTAL RESULTS The data obtained are summarized in Table I, and some are given in detail in Figs. 1 to 4. In the fourth column of Table I, kp refers to the parabolic rate constant in the expression (?/cm2)2 = kpt + c [1] where ? = micrograms gain in weight kp = parabolic rate constant in units r2 /cm4 t = time in minutes c = constant It will be noted that in many cases no value for kp is given; this is because in these instances the data did not obey the parabolic rate law. The silica film thicknesses given in the last columns are values calculated from the weight gain, an average tridy-mite-crystobalite density, and by assuming a perfectly plane surface. Fig. 1 shows the data plotted in the form of Eq. [I], hence a linear plot indicates parabolic behavior. It has been frequently observed in the literature that

Jan 1, 1960

By J. C. Wynn

This paper outlines research conducted by the US Geological Survey on the geophysical signatures of chromite. Results of the chromite study highlight the importance of a laboratory research Phase (petrophysical and petrographic studies) at the beginning of work on a new commodity; a realistic ore deposition model to serve as a conceptual framework, and the necessity to continually test, refine, and modify it during the study; and indirect geologic/geochemical indicators, secondary associations, and the use of multiple physical properties. The keystone to the success of the study is frequent and substantive dialogue among geologists, geophysicists, and geochemists.

Jan 1, 1984

Discussion of the paper of Edward Keller, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 2093 to 2115. GEORGE L. HEATH, Hubbell, Mich.:-In the admirable paper quoted, is mentioned the date when the 5-g. assay was first proposed is a standard for refined metal. The author omitted, however, to mention a later paper,1 which contains a proposal for the use of a single " stock solution " of mixed acids, which has been adopted by the American Brass Co. and others. The suggestion is made that such a scheme would save time and manipulation with converter metal. Unless the low current of 0.5 ampere and the large excess of nitric acid, recommended by Mr. Keller, have been proved necessary to hold up antimony-and selenium, the use of the mixed solution which we have adopted will permit the use of 1 ampere of current per square decimeter of cathode surface, until the solutions have become colorless. At this point, we wash the covers and reduce to 0.5 ampere to prevent oxidation or contamination. The ordinary split electrodes have been used. With strong current, at least, the use of an excess of nitric acid tends to the neutralization of the solution before the end of the period, from the formation of too much ammonia., and this is detrimental. Antimony deposits more easily than arsenic, and tends to drag the latter dorm with it. There must, be some such explanation for the fact. that we have made hundreds of deposits of pure cathodes from Lake material containing no antimony, but as. high as 0.5 per cent. of arsenic. By placing an assay beaker in the Frary solenoid, or rotary device, a cathode deposit with less than 0.01 per cent. of impurity is easily obtained in one operation from 3 g. of whitneyite, carrying from 7 to 10 per cent. of arsenic. In such a case, it is necessary to test several times for end point and remove the plate as soon as no brown tint appears (at once) when hydrogen sulphide water is added to the test portion on the spot plate. Edward Keller&apos;s proportion,, of solvent figure out as 14 cc. of strong nitric to 11.4 cc. of sulphuric acid (1.84).

Jan 11, 1913

By W. M. Courtis

THIS district commences near Pigeon River, the northeastern boundary between Minnesota and Province of Ontario, and extends entirely around the north shore of Lake Superior, terminating for the present at the Bruce Mines on Lake Huron. The discoveries of mineral-bearing veins have been confined for the most part to the lake shore, or to the country opened up by the Dawson Red River road. As yet the country back from the lake has been but little explored, on account of its roughness, being intersected by steep, rocky trap bluffs, 1000 or more feet high, and alternating white cedar and tamarack swamps. The forests are exceedingly difficult for prospectors. In many places Titanic piles of rocks, protected by chevaux-de frise of dead cedars, with their hooked, tough, sharp branches, and- a covering of spongy moss, sometimes several feet thick, successively guard against the discovery of hidden treasure. The Hudson&apos;s Bay Company for nearly a century have maintained trading-posts at Fort William and other points, which probably opened the way to the first discoveries that were made at Prince&apos;s Bay, near the western limit of the district. At this point a large vein was worked by Colonel Prince, the owner, as early as 1846. The richest part of the vein seems to have been on Spar Island, but work was stopped on account of excess of water. Sir William Logan states that a mass of ore weighing several hundred pounds and carrying 3 per cent. of silver was taken out. On the mainland small quantities of native and sulphide of silver were found, together with iron and copper pyrites, zinc blende, and galena, in a large spar vein. On the main shore a drift 165 feet long and 90 feet in depth

Jan 1, 1877

By R. N. Kust, J. C. Agarwal, H. E. Barner, N. Beecher, D. S. Davies

Kennecott Copper Corp. has developed a new hydro-metallurgical process for extracting nickel, copper, cobalt and molybdenum from manganese nodules. This process (KCC Cuprion Process) utilizes a reduction leach operating at atmospheric pressure in the temperature range of 45 OC to 50°C and has been successfully demonstrated in a continuous pilot plant processing 350 kg/d of nodule ore. The chemistry, basic flowsheet and operating characteristics are presented and discussed.

Jan 1, 1980

By Petter Östberg

Having brought with me to this meeting a couple of "Mitis&apos;&apos; wrought-iron castings, I have found that they attracted a great deal of attention from steel manufacturers, and especially from those experienced in making castings, among whom some have said that they felt inclined to "unhesitatingly dcclare their manufacture an impossibility," if they had not seen the samples. The consequent demand for explanation of the method of manufacture has been SO great that I accept with pleasure the request by the President to address the meeting on the subject. My object in this address shall be only to explain the main features of the manufacture, referring those who take more interest in the matter to Mr. Th. Nordenfelt&apos;s paper, read before the British Iron and Steel Institute, reprinted in many American papers, and containing both a historical sketch of the inventions and many interesting details. As the manufacture of castings from steel by others is, at least to some extent, a success, I shall, in my explanations hereafter, refer to wronght-iron, although our mode of manufacture is equally applicable, with corresponding advantage, to steel of any temper. The successful manufacture of castings depends upon several very important matters, besides the necessary skill of the workman. You must have a suitable metal as raw material; you must have an eacient and suitable furnace for smelting, so as not to injure the metal; you must be able to handle the metal in a suitable way, from the time it is ready in the furnace until it is poured into the moulds; you must have a suitable moulding material. I claim that in every one of these different branches we have made great

Jan 1, 1886

By A. E. H. Bergmann

INTRODUCTION The Sachtleben Chemie GmbH in Duisburg, a subsidiary of the Metallgesellschaft AG, operates a new sulfuric acid plant that employs fluid bed roasting of pyrite concentrates. The plant produces about 300,000 tons per year of pyrite cinders from the fluid bed roasting unit. The cinder product consists of 58 percent iron and is about 80 percent by weight smaller than 50 microns. This cinder product was found to be a competitive source material for the cement industry as the iron-containing additive. However, the extreme fineness of the cinder and its dusting tendency were undesirable and an agglomerating technique became necessary. In order to keep the price of agglomerated pyrite-cinders at a competitive level, the agglomerating method must be chosen such a way the capital and operating costs are low. Initial experiments were carried out on a laboratory scale to make an appropriate choice of the agglomerating method. Major goals of agglomerating the cinders were to improve the transportation, storage, and proportioning and metering properties. Minimum specifications are put on the size, size distribution and shape of the product. Criterion for handling is that a minimum of minus one mm. fines are produced after several handlings, while for storage, it is also desirable for the agglomerated product to survive several months in open air. Thermal agglomeration processes such as sintering one known to produce excellent products, but are by far too expensive for our application. For the same reason, granulation, balling, and pelletizing tests with addition of organic binding agents, such as tylose, starch, sulfite wash, molasses, etc. were not continued. The costs for the binding agent was considerable, which is probably due to the high pore volume of our cinders (35 %). Furthermore, the pellets or granules

Jan 1, 1977

By Thomas MacFarlane

During the last fifteen years the progress made in the science of lithology has been of a very marked character. From being a miscellaneous collection of facts and observations regarding certain mineral aggregates seemingly incapable of systematic arrangement, it has become a most interesting and orderly department of science. The investigators who have brought about this great change have recorded the results of their labors, and placed at our service an extensive and varied literature on the subject. To this I have paid some attention, and partly from studying it,, partly from my own observations, I have wrought out a classification of original or crystalline rocks, which I venture to bring under the notice of the members of this Institute. The practical importance of the subject will be acknowledged when it is considered that rock species are not without their influence on the contents of the mineral veins which intersect them. Besides, the Institute has been doing good service in defining terms in metallurgy, and no doubt in mining and geology we might

Jan 1, 1880

By Thomas MacFarlane

DURING the last fifteen years the progress made in the science of lithology has been of a very marked character. From being a miscellaneous collection of facts and observations regarding certain mineral aggregates seemingly incapable of systematic arrangement, it has become a most interesting and orderly department of science. The investigators who have brought about this great change have recorded the results of their labors, and placed at our service an extensive and varied literature on the subject. To this I have paid some attention, and partly from .studying it, partly from my own observations, I have wrought out a classification of original or crystalline rocks, which I venture to bring under the notice of the members of this Institute. The practical importance of the subject will be acknowledged when it is considered that rock species are not without their influence on the contents of the mineral veins which intersect them. Besides, the Institute has been doing good service in defining terms in metallurgy, and no doubt in mining and geology we might

Jan 1, 1880

By David Reger

LITTLE new oil was found in West Virginia, during 1923, but there were important discoveries of gas. Most of the large oil producers have contented themselves with pumping old wells or in drilling only enough new wells in defined territory to maintain a fairly constant production, the attitude being that no, profit is made in producing high-grade oil at a low price and that an eventual loss is sustained by draining the reserves of a limited commodity that, at some more favorable time, will be of much value. The representative of one large company said: "We have done nothing but pump old wells during 1923 and we have made no plans for 1924." Careful attention to producing wells has been the rule, there having been few abandonments; the belief is prevalent that small wells will eventually become profitable under more favorable marketing conditions. In natural gas, the opposite point of view prevails. Because of the vast capabilities of the state for producing gas, its output being ahead of all others, great systems of transportation and distribution into the markets of four adjoining states have been built and a demand has been created that no present, or apparently potential, production can satisfy. This demand has become so great that large distributing companies not only discourage new applications for service but advise old customers to install coal furnaces for auxiliary fuel; some have requested public-service commissions to grant higher &apos;rates against large industrial consumers than those allowed for domestic heating. The response to this known market has been a rapid increase in price, both at the well mouth and at the door of the ultimate consumer, and the industry has become so stable that the only uncertainty, or hazard, appears to be the question of the presence of gas in fair quantity in a given territory under consideration. Several oil companies have now forsaken their policy of selling gas, wells outright when drilled and ;have organized gas departments to drill for gas and to dispose of the daily output by meter to distributing corporations. With such companies and with other producers whose interest is chiefly gas, the year has been busy and profitable. Some new territory of apparently large value has been proved and deeper producing sands in old fields have been tapped.

Jan 3, 1924

By R. McEwen, G. W. Hansen, G. F. Lee

The effect of using an anionic collector, Reagent 308, a sodium petroleum sulfonate, with a cationic collector, Armac T, a tallow, fatty acid amine acetate, was studied in a series of monomineralic flotation trials with the alkali feldspars and heavy minerals, ilmenite, rutile, garnet, and monazite. This combination of cationic and anionic collectors is employed to float feldspar and heavy minerals from quartz in the beneficiation of sand in Normanville, South Australia, to produce a suitable quartz sand for glassmaking. In the alkali feldspar trials, Armac T additions were held constant, while the 308 additions were varied. In the heavy mineral trials, the 308 was held constant while the Armac T was varied. Peak enhancement of the feldspar recovery was noted when the 308 additions were between 25% and 150% that of the Armac T additions. At higher 308 addition, depression of feldspar flotation occurred. This appears to be due to a neutralizing effect in the combined collector system and to the formation of a nondissociating complex of both collectors. This variability in flotation response when Armac T is used with 308 suggests that the two collectors do not act independently of each other.

Jan 1, 1977

By K. Winterton

The effect of a near-saturation unidirectional magnetic field was to decrease slightly the endurance life in Armco iron in the annealed condition. This is expected since the energy-absorbing mechanism associated with domain wall movemenfs is inhibited bv the strong field. THE factors determining failure under dynamic loading are not yet clearly recognized. One of the properties of a metal which might be thought to influence fatigue life is its damping capacity. Foppl1 conducted an alternating torsion test at a frequency of 700 cpm continuously for a period of 3 years, without the test piece breaking or showing any sign of deterioration after 1100 Million cycles of stress; the rate of dissipation of energy was sufficient to maintain the test piece at about 100°C above the ambient temperature. cazaud2 concludes from this, and others follow him, that (&apos;the capacity for dissipation in the form of heat by internal damping is unlimited" and that therefore "damping is not directly related with fracture by fatigue." Future work may necessitate qualification of this rather uncompromising view. It is shown later that in all

Jan 1, 1960

By Robert Sisselman

If we are lucky," says Hollis M. Dole, Assistant Secretary of the Interior, "coal, uranium and hydropower will provide us with maybe a third of the energy we require in 1985. The other two- thirds will have to be made available in liquid and gaseous form." Luck, however, may have run out, for if the facts and figures relating to supply and demand of natural gas over the next 20 years prove accurate, the United States may fall short in its attempts to bring the energy crisis under control. By the year 1990 the world will need to consume a minimum 150 quadrillion Btu of energy with gas requirements running as high as 42-43 trillion cu ft. By 1990, the U.S. alone will require 45-46 trillion cu ft. To meet anticipated demand, this country will have to overcome a deficiency of about 20 trillion cu ft since, by all pragmatic estimates, it will produce only 15-20 trillion cu ft of gas. The importation of natural gas into the U.S. will help but will not solve the problem. Adequate gas supplies will have to be supplied domestically. The Arctic, with its predicted huge reserves of gas, combined with imports of liquid natural gas (LNG) may provide as much as 15% of the 45-46 trillion figure, however, such reserves will not come into play as quickly as originally thought. The Alaskan gas fields, for instance, will provide a substantial supplement to domestic gas needs, but only after 1976.

Jan 10, 1972

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

By David R. Maneval, Jack M. Campbell

The regulatory process by which governmental authorities acknowledge and, in turn, permit the location, construction, and operation of large scale energy-related facilities has become extremely detailed in recent years. One example of the detail that is entailed in the regulatory process is the number of permits that must be acquired by operators prior to the construction and operation of energy-related facilities. It has been estimated, for example, that 75 permits are required prior to the opening of a new coal mine in Pennsylvania while 50 are required in Kentucky. From the perspective of facility owners and operators the regulatory process often appears overly complex and may be perceived as a constraint to the corporate decision making process. From the perspective of those responsible for administering regulations, the process is perceived as a means by which public desires-pursuant to social objectives such as environmental protection and occupational safety-can be achieved. As a result of conflicting organizational interests, the clash between energy facility owners and operators and their regulators appears to be inevitable. Furthermore, the resolution of this conflict lies in the trade-off between objectives and the costs of regulation. The balance of objectives and costs is a subject of the political process and not a topic of consideration in this paper. This paper is concerned with the actual administration of regulations, that is, the implementation of that which arises from the interplay of organizational interests. The paper assumes that environmental control laws will not likely be repealed, that regulations to implement the intent of these laws are here to stay and thus the paper seeks to assess how regulations are administered at various levels of government pursuant to objectives. The paper hypothesizes that the administration of objectives (or policy) has an impact on decision making which affects energy facility decision making. While recognizing the fact that regulatory policy cannot be totally divorced from administration, this paper proceeds under the assumption that elements of the regulatory process may be examined individually. The subject of this study is limited to the interplay between regulatory agencies and their clientele.

Jan 1, 1979

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

The following paper, submitted by the Russian petroleum authorities, was secured through the courtesy of G. V. Ackerman, Vice President of Amtorg Trading Corporation, and N. V. Vannikoff, Representative in the U.S.A. of the United Oil and Gas Industries of the U.S.S.R. It gives an excellent view of the Russian petroleum industry as seen through Russian eyes. Noteworthy is the tremendous area over which the Russians are searching for petroleum, for this paper refers to such far-flung areas as the Arctic Tamir Peninsula, Kamchatka and Sakhalin on the Pacific, Lake Baikal in Central Siberia, the great new discovery at Neftadag in the plains of West Turkestan, and the oil of the Ferghana oasis, where the derricks look out over to the mosques of Kokand. Of interest also is the new pipe line to supply the industrial centers of Ukraine grouped around the great hydroelectric plant built at Dneprotroy on the falls of the Dnieper. The technical achievements have been noteworthy and we must pause to consider the scope of the undertakings being carried forward. Russia is at the worst a good second to the United States in petroleum reserves and for a long time to come will be a most important factor in the petroleum markets of the world. Her story should be of interest to everyone in the industry. The First Five Year Plan The first Five Year Plan, covering the period 1928-29 to 1932, accomplished the task of transforming the Union of Soviet Socialist Republics from an agricultural, backward land into a powerful independent industrial country, with an advanced technological foundation of its own for finally achieving the social reconstruction of the entire national economy. Along with the gigantic forward &apos;strides in industry and transportation, radical changes took place in agriculture. The creation of more than 5000 great state farms and of more than 200,000 collective farms serviced by a widespread network of machine-tractor stations has brought the U.S.S.R. to the fore as the largest agricultural country in the world. Imports of tractors and other agricultural machinery in the initial years of the Five Year Plan and the intensive output of this equipment by the great plants of the U.S.S.R. in the latter years of the plan have brought about the mechanization of agriculture in the Soviet Union. This year 250,000 tractors and 30,000 combines will operate in the fields

Jan 1, 1934

By C. M. St. John

INTRODUCTION The stress redistribution accompanying the excavation of a deep tunnel may induce failure of the rock. The role of the support system is to control the extent of the failed region and hence to limit closure of the tunnel within an allowable amount. In such circumstances, the design of the support system is generally based on the Ground Reaction Curve (GRC). The GRC is the relationship between the support pressure and the induced displacement at the tunnel wall for a circular tunnel under hydrostatic loading. In the calculation of the GRC (see Brown et al. (1983) for an exhaustive list of reference), the rock is generally treated as an elastoplastic material characterized by cohesive-frictional yield strength and by dilatancy during plastic deformation. A recent analytical development (Detournay, 1983) has allowed the generalization of the GRC concept for some cases of non-hydrostatic in-situ stress fields (Detournay and Fairhurst, 1982). As an application of that development, this paper describes design charts that provide powerful means of performing parametric analysis for tunnels subject to non-hydrostatic loading. BACKGROUND The in-situ stress in a plane perpendicular to the tunnel axis can be decomposed into mean and deviatoric components, Po and So (see Fig. 1). Since it is assumed that the rock is characterized by a Mohr-Coulomb yield strength, the deviatoric invariant So must be less than the limiting value Sl0 given by

Jan 1, 1984