Search Documents

By C. F. Park

Hog Mountain is in the north central part of Tallapoosa County, Alabama, about 13 miles northeast from Alexander City. The Hog Mountain Mining and Milling Co. controls 1658 acres of land and is the only company operating in the district. The principal mine workings are in sections 10 and 15, T.24N., R.22E. The region has been visited by geologists many times, has been briefly described in several papers,' and mentioned in many others. No detailed map of the mine or vicinity has been published. The field work for this report was started in March, 1934, as part of the Public Works reemployment program. About a month and a half was spent mapping both the surface and underground geology. The mine owners and operators have cooperated in every way possible to facilitate the work. N. 0. Johnson, the mine engineer, E. W. Ellsworth, J. E. McCoy and J. G. Englebert have acted as assistants for part of the work. The University of Alabama and the State Geologist's office have aided materially by permitting free use of their libraries and laboratory equipment. Geography Hog Mountain forms a conspicuous ridge that rises to a height of a little more than 1000 ft. above sea level, and about 400 to 500 ft. above the adjacent country. The ridge is composed of granitoid intrusive rock and silicified schist that are more resistant to erosion than the surrounding softer schist. The topography of the area around the ridge is gently rolling and is typical of the subdued forms of the deeply eroded Southern

Jan 1, 1935

By C. F. Park

Hog Mountain is in the north central part of Tallapoosa County, Alabama, about 13 miles northeast from Alexander City. The Hog Mountain Mining and Milling Co. controls 1658 acres of land and is the only company operating in the district. The principal mine workings are in sections 10 and 15, T.24N., R.22E. The region has been visited by geologists many times, has been briefly described in several papers,' and mentioned in many others. No detailed map of the mine or vicinity has been published. The field work for this report was started in March, 1934, as part of the Public Works reemployment program. About a month and a half was spent mapping both the surface and underground geology. The mine owners and operators have cooperated in every way possible to facilitate the work. N. 0. Johnson, the mine engineer, E. W. Ellsworth, J. E. McCoy and J. G. Englebert have acted as assistants for part of the work. The University of Alabama and the State Geologist's office have aided materially by permitting free use of their libraries and laboratory equipment. Geography Hog Mountain forms a conspicuous ridge that rises to a height of a little more than 1000 ft. above sea level, and about 400 to 500 ft. above the adjacent country. The ridge is composed of granitoid intrusive rock and silicified schist that are more resistant to erosion than the surrounding softer schist. The topography of the area around the ridge is gently rolling and is typical of the subdued forms of the deeply eroded Southern

Jan 1, 1935

Hog Mountain is in the north central part of Tallapoosa County, Alabama, about 13 miles northeast from Alexander City. The Hog Mountain Mining and Milling Co. controls 1658 acres of land and is the only company operating in the district. The principal mine workings are in sections 10 and 15, T.24N., R.22E. The region has been visited by geologists many times, has been briefly described in several papers,' and mentioned in many others. No detailed map of the mine or vicinity has been published. The field work for this report was started in March, 1934, as part of the Public Works reemployment program. About a month and a half was spent mapping both the surface and underground geology. The mine owners and operators have cooperated in every way possible to facilitate the work. N. 0. Johnson, the mine engineer, E. W. Ellsworth, J. E. McCoy and J. G. Englebert have acted as assistants for part of the work. The University of Alabama and the State Geologist's office have aided materially by permitting free use of their libraries and laboratory equipment. Geography Hog Mountain forms a conspicuous ridge that rises to a height of a little more than 1000 ft. above sea level, and about 400 to 500 ft. above the adjacent country. The ridge is composed of granitoid intrusive rock and silicified schist that are more resistant to erosion than the surrounding softer schist. The topography of the area around the ridge is gently rolling and is typical of the subdued forms of the deeply eroded Southern

Jan 1, 1935

By C. F. Park

Hog Mountain is in the north central part of Tallapoosa County, Alabama, about 13 miles northeast from Alexander City. The Hog Mountain Mining and Milling Co. controls 1658 acres of land and is the only company operating in the district. The principal mine workings are in sections 10 and 15, T.24N., R.22E. The region has been visited by geologists many times, has been briefly described in several papers,' and mentioned in many others. No detailed map of the mine or vicinity has been published. The field work for this report was started in March, 1934, as part of the Public Works reemployment program. About a month and a half was spent mapping both the surface and underground geology. The mine owners and operators have cooperated in every way possible to facilitate the work. N. 0. Johnson, the mine engineer, E. W. Ellsworth, J. E. McCoy and J. G. Englebert have acted as assistants for part of the work. The University of Alabama and the State Geologist's office have aided materially by permitting free use of their libraries and laboratory equipment. Geography Hog Mountain forms a conspicuous ridge that rises to a height of a little more than 1000 ft. above sea level, and about 400 to 500 ft. above the adjacent country. The ridge is composed of granitoid intrusive rock and silicified schist that are more resistant to erosion than the surrounding softer schist. The topography of the area around the ridge is gently rolling and is typical of the subdued forms of the deeply eroded Southern

Jan 1, 1935

By AIME AIME

ABOUT one hundred were in attendance when Donald M. Liddell opened the session* on non-ferrous metallurgy at 2 p. m. on Tuesday. F. F. Col- cord was vice-chairman. For the first part of the session the chair was turned over to Frank G. Breyer, who introduced G. L. Spencer, Jr., to read his contribution (T.P. 378), "High Silica Retorts at the Rose Lake Smelter," which was an account of the method of manufacture of high-silica zinc retorts at the Rose Lake smelter, and of the service given by these retorts. The materials used are, by volume, 50 per cent clay, 25 per cent silica flour and 25 per cent grog. Written discussion of the paper by E. M. Johnson, W. R. In- galls and M. M. Neale was read by Mr. Breyer. Mr. Johnson explained that their practice in manufacture differed very little from Rose Lake practice, but that their retorts did not last as long, possibly because Eagle-Picher does not use a hydraulic retort press or sintered ore. He ascribes the longer life of silica re- torts to the fact that they do not bend under heat. Mr. Ingalls pointed out that silica retorts are no better as heat conductors than clay retorts, but that they do have a superior rigidity in the furnace. The character of the retorts does not affect the density of the charge. Mr. Neale gave the procedure in the manufacture and use of high-silica retorts at the Donora zinc works, not

Jan 1, 1931

By Harry L. McNeill

THE Selective Media Process was developed by the author in a laboratory provided by The Steårns-Roger Manufacturing Co. It is the outcome of an [ ] investigation into the possibilities of coarse beneficiation by sink and float without using the conventional heavy media. Commercial work to date has been limited to the treatment of minus 3/8-in. iron ore at the Hill Trumbull washing plant of the Cleveland Cliffs Iron Co., at Calumet, Minnesota. Two cut away prints of the machine are shown (Figs. I and 2). A rotary conical impeller is mounted within a stationary cone (Fig. 2). This impeller is adjustable vertically by a 12-ton screw jack. The speed of the impeller can be varied from 14 to 32 r.p.m. by the Reeves variable-speed motor pulley mounted on the 7 ½ -hp. motor drive. Attached to the bottom of the stationary cone is the automatic control valve for sink product, actuated by a ¼ -hp. gear motor. The sink product is dewatered in a conventional drag driven by a 7 ½ -hp. motor and discharged onto an inclined conveyor containing from 6 to 10 per cent moisture. Two plants are operated at the Hill Trumbull property. All the ore is first treated in a typical washing plant (Fig. 3). When treating "wash ore" a finished concentrate can be produced by the log washers and Akins classifiers, as the separation involves only fine silica (minus 48-mesh) and free iron. However, when "jig ore" is fed to the washing plant the coarse

Jan 1, 1946

By Tracy Jarrett

In 14-karat gold alloys, as in 10-karat gold alloys,3 the addition of such metals as zinc, nickel, copper and silver produces a wide range of physical and chemical proper-ties such as color, hardness, corrosion resist-ance and melting points. These important factors made gold alloys desirable in the optical work and for jewelry. In 14-karat gold alloys, as well as in 10-karat or 12-karat, it is possible to have two golds of the same color, one of which will corrode more than the other, although it may be harder. Some of these alloys have been investigated by F. E. Carter,1 E. M. Wise,5 and L. Sterner Rainer.4 In this group of alloys the gold content of 58.3 per cent (14-karat) was held constant, while the copper varied from 36 to 24 per cent. The balance of the alloy consisted of one, two, or three of the metals silver, zinc, and nickel. All the alloys were melted in an induction furnace and cast into an ingot that meas-ured 3 by 1/4 by 3/4 in. The method of determining the melting points, color deter-minations and acid test have been discussed in previous papers by the author.2,3 It is necessary to use small test bars (Fig. r). The tensile bars were annealed at 1300°F. for 20 min. and then air-cooled. There being a very marked drop when the yield point was reached, "the drop of the beam" method was used in determining the yield point.

Jan 1, 1940

Economic Significance of High-grade Concentrates BY PAUL M TYLER AND CARLE R HAYWARD (Min & Met, Dec, 563 4000 words) Generally pyro¬mctallurgical methods yield a higher recovery but cost more per ton of ore treated Milling methods are inherently cheaper for the reason that they do not involve dissipa¬tion of heat energy in slag formation, ctc It is vaguely realized that the smelter man could do a better job if he were supplied with purer raw materials but hard¬headed mill men have been offered little inducement to do a really good job of cleaning concentrates To do this may involve some sacrifice in percentage yield and in mill capacity and unless there is a compensating saving in freight and smelter charges, it simply is not good business to go beyond a certain point in the way of making clean concentrate Opportunities exist for eliminating one or more steps in the expensive series of processes for recovering various metals, or at least reducing the volume of materials that has to be handled at the most costly steps The beneficiation of nonmetallic minerals likewise affords numerous examples of over-all economies obtainable through more refined methods of mechanical improvement All this leads to the conclusion that perfecting selective processes for isolating pure minerals (e g, galena) virtually free from other sulfides as well as gangue may be productive of industrial economies Conversely, cheapening smelting methods may invade the field of mechanical improvement of ores but, as Kiphng said, that is another story

Jan 1, 1937

By H. Rush Spedden

R. T. Hukki has extended his study of ball mill grinding at supercritical speeds with an excellent mathematical analysis of tumbling mill grinding. When he speaks of supercritical speeds he is referring to the original Fahrenwald critical-speed formula. He said that, as an example of the use of supercritical speeds, if a fine grinding mill of any type is wet-grinding ore of 3.5 sp gr with steel balls at a certain conventional subcritical speed, the same power input and capacity should be obtainable with autogenous medium of 3.5 sp gr at a speed 100 to 120 pct of the critical in a grate- type mill of the same effective size. In addition, he introduced what he calls the base mill concept which, he stated, makes it possible to compare performances of mills of different sizes grinding with a metallic medium or with an autogenous medium of any specific gravity and at any speed. He showed the use of this concept and explained how it makes possible the evaluation of mill sizes and motors for any grinding purpose at any accuracy well within the conventional standards of design in milling practice. He further stated that the maximum capacity in pilot plant mills with various media, either metallic or autogenous, has always been found to be within the supercritical speed range. In his discussion of this paper he substantiated these findings with statements showing the increased capacity obtained in a milling plant in Finland which followed his principles.

Jan 7, 1960

By H. R. Peterson

The control of autogenous grinding circuits is very similar to the control of conventional grinding circuits. In both circuits the classifier must be operated to achieve the required degree of mineral liberation. Crude ore grade and grinding mill density are important in both circuits. The biggest difference between the control of the two circuits is the pronounced effect that crude ore changes have on autogenous circuits. The importance of crude grade, weight recovery, size and hardness is greatly magnified because the crude ore in the autogenous circuit is also supplying the grinding media. Crude ore sizing is a particularly critical factor in achieving efficient primary autogenous milling. Because of the above, computer control is advantageous for autogenous circuits. Changes in crude ore may necessitate rapid changes in the entire circuit control strategy, and only a computer can facilitate these changes. Also, the techniques of control are very different for conventional and for autogenous grinding. Set-point control is usually satisfactory in conventional circuits, but the multiplicity of varying conditions in an autogenous circuit usually require some type of computer optimizing search routine. Autogenous mills can be separated into two general types. In primary autogenous mills the media is obtained from the mill feed, and in pebble mills the sized pebble media is added separately from the material being ground. PRIMARY AUTOGENOUS MILL CIRCUIT CONTROL - FIGURE 1 Power Draw Primary autogenous mills are usually run at full motor loading so production will be at maximum. Therefore, power draw must be closely controlled; this is done by adjusting feed rate. The versatility of computer control is extremely valuable for power control, especially during starting and stopping. To bring the mill power up as fast as possible at

Jan 1, 1982

By Charles Y. Clayton

A study of the literature shows that the greater part of research work on annealing of cold-worked iron has been for the purpose of studying the effect on grain-size and properties other than hardness. No reference has been found of experimental work of the same nature as that explained in this short paper. The material used throughout was Vismera iron, an iron containing 0.03 carbon and made several years ago by the Inland Steel Co. One-half inch stock was cut into cylinders % in. long. The cylinders were then compressed for 60 sec. in a Reihle testing machine under loads as indicated below: CoMPressiON, Average Length, Series Pounds Inches 1 10,000 0.693 2 15,000 .599 3 20,000 .501 4 25,000 .426 5 30,000 .378 6 35,000 .351 7 40,000 .311 Fig. 1 shows these cylinders after compression. Each series consisted of 17 specimens lettered 0, B, C, D, E, F, G, H, I, J, K, L, M, N, P, Q and R. One specimen of each series was reserved for study of the properties in the cold-worked condition. The other specimens were annealed in a Hump furnace for 1/2 hr. at the following temperatures: TEmpeRa- TempeRa- Letters tuRe,° C. LettERs tuRe °C. B............................... 250 J.............................. 650 C............................... 300 K............................. 700 D............................... 350 L.............................. 750 E............................... 400 M............................. 800 F................................ 450 N............................. 851 G............................... 500 0. . :........................... 900 H............................... 550 P.............................. 950 I................................ 600 Q............................. L000

Jan 1, 1926

By G. S. Hume

TuRneR Valley, on the eastern edge of the foothills of Alberta, 35 miles southwest of Calgary, continues to be the major oil field in Canada. This field began production of gas and naphtha from the Mississipian (Madison) limestone in 1924, and until 1936 all wells were drilled for these products. At the end of 1938 there were 104 gas wells. In 1936 proof was found of a crude oil zone in the same horizon but lower on the west flank of the structure, which is a large fold cut off on the east side by an overthrust fault of great displacement. Since 1936 drilling has been done for the development of crude oil and at the end of 1938 there were 64 crude oil wells. On test through a 1-in. choke these flowed at the rate of 50,000 to 60,000 bbl. a day, but on production would not be expected to make this volume. The output has been prorated according to the capacity of the Prairie market. During the harvest season, when the demand for oil and oil products was at its maximum, the allowable production of Turner Valley was 28,363 bbl. per day. With the arrival of winter, this was cut to 11,500 bbl. per day but later was raised to 12,500 bbl. Production in 1937 from Turner Valley was 2,767,221 bbl., which was more than double that of the previous year. Production in 1938 was 6,691,075 bbl., which is considerably more than double that of 1937.

Jan 1, 1939

By G. S. Hume

TuRneR Valley, on the eastern edge of the foothills of Alberta, 35 miles southwest of Calgary, continues to be the major oil field in Canada. This field began production of gas and naphtha from the Mississipian (Madison) limestone in 1924, and until 1936 all wells were drilled for these products. At the end of 1938 there were 104 gas wells. In 1936 proof was found of a crude oil zone in the same horizon but lower on the west flank of the structure, which is a large fold cut off on the east side by an overthrust fault of great displacement. Since 1936 drilling has been done for the development of crude oil and at the end of 1938 there were 64 crude oil wells. On test through a 1-in. choke these flowed at the rate of 50,000 to 60,000 bbl. a day, but on production would not be expected to make this volume. The output has been prorated according to the capacity of the Prairie market. During the harvest season, when the demand for oil and oil products was at its maximum, the allowable production of Turner Valley was 28,363 bbl. per day. With the arrival of winter, this was cut to 11,500 bbl. per day but later was raised to 12,500 bbl. Production in 1937 from Turner Valley was 2,767,221 bbl., which was more than double that of the previous year. Production in 1938 was 6,691,075 bbl., which is considerably more than double that of 1937.

Jan 1, 1939

WHEN Magma Copper Company in 1952 set about finding $100,000,000 to finance the project of developing and equipping the property of its lusty progeny, the San Manuel Copper Corporation, A. J. McNab, president and guiding genius for both companies (and incidentally a mining engineer by profession), determined that he would avoid the mistake frequently made in such circumstances, of underestimating the cost, and thereby running short of funds before the job was completed. The fear that this might happen was one of the reasons why insurance companies, one potent source of "big" money, were reluctant to finance the enterprise. How, they asked themselves, would Magma, a relatively small company, get additional money in such a contingency? Insurance officials' thumbs were turned down. Conditions Imposed by R.F.C. The upshot was the negotiation by Mr. McNab for San Manuel of a contract with the Reconstruction Finance Corporation, dated July 10, 1952, whereby needed monies in amount up to $94,000,000 would be advanced as a loan, bearing 5 per cent interest. Arrangements were made for the separate financing of the new $10,000,000 town, needed for the project, through the Del E. Webb Construction Company of Phoenix, Arizona, and M.O.W. Homes, Incorporated, of Los Angeles. Thus the $94,000,000 drawing account was believed ample to provide for building the railroad, the mine plant, the concentrator, and the smelter, as well as for the underground development of the mine needed to start production. As a matter of fact, only

Jan 1, 1957

By Carl Samans

IN their recent complete review of the subject of age-hardening,1 R. F. Mehl and L. K. Jetter classify the main types of precipitation-hardening alloys under two headings, depending upon the nature of the precipitate and the character of the precipitation. In the alloys falling under the first heading, which display "continuous precipitation" and are typified by the aluminum-copper alloys, "precipitation seems to occur without much regard to grain boundaries and apparently at much the same rate at every point," although an acceleration in regions plas-tically deformed has definitely been established .2 In the second type of alloys the precipitation is "discontinuous," as in the copper-silver system for example, and "seems to start in restricted regions, primarily those contiguous with the grain boundaries, and to spread inward in an advanc-ing wave." The reasons for the occurrence of these two greatly different types of precipitation are unknown, as are those for many other reactions that take place in the solid state. In the present paper only the first or "continuous" type of precipita-tion will be dealt with, for which a complete crystallographic mechanism has been worked out for the process of precipitation from a supersaturated solid solution of copper in aluminum. Based upon this mechanism, an explanation of the various property changes found experimentally will be developed in the second paper of this series. In later papers "dis-continuous precipitation" in copper-silver alloys will be explained, and an effort will be made to rationalize the two processes and types of precipitation.

Jan 1, 1940

By Erwin S. Sperry

The presence of small amounts of tellurium in certain binds of copper, and its exceptionally deleterious* influence in producing red-shortness of this metal, led the author to conduct a few experiments on the influence of tellurium on the properties of brass. While these experiments were not intended to be exhaustive, they demonstrate that, as far as the rolling of brass is concerned, tellurium, unless it occurs in far greater amounts than exist in refined copper, cannot be called an injurious impurity. In comparatively large amounts it appears to impart cold-shortness to high-brass. Tellurium, the rare element that it is considered to be, has recently been extracted on a large scale from the slimes of an American electrolytic copper-works. They have, in attempts to discover some commercial use for it, sent it out promiscuously and gratuitously in quantities which would lead the young chemical student to fancy that a rare element exists only in name. Through the courtesy of Mr. R. L. Whitehead, of Baltimore, the author was able to obtain somewhat over 2 lbs.,? and use it in quantities which, at the market price, would be prohibitive. In order to add specific quantities of tellurium to brass, a rich alloy of copper and tellurium was previously made. The method was as follows, viz.: Nine and one-half lbs. of Lake copper were melted un-. der charcoal in a new plumbago crucible, and then pound of tellurium was added in small portions at a time. The mixture was stirred with a plumbago-stirrer and poured into

Jan 1, 1903

By R. W. Raymond

R. W. Raymond, New York City: In his paper at the New York meeting (Trans., xix., 28), Mr. Ledyard described, among other mines, the Belmont, in the county of Peterboro, Ontario, the developments of which at that time indicated, though they did not, perhaps, completely demonstrate, a deposit of high-grade Bessemer magnetite of very great extent. Mr. Ledpard said that experts estimated the quantity of ore within 100 feet of the surface at 1,000,000 tons. But the precise data upon which this estimate was based were not furnished. We are all interested in the development of fresh supplies of Bessemer ores. I think nobody who knows how enormous is the demand can seriously fear that such deposits will be exploited too rapidly. On the other hand, I need not here enlarge on the fact that a considerable number of enterprises, in which American ironmasters have been more or less interested, for the development of Canadian iron-ore deposits, have been unsuccessful, more by reason of disappointment as to the quantity of the ore and the facilities for cheaply mining it on a large scale, than as to its quality. Of course, a Canadian nine supplying the American market is handicapped at present, to the extent of 75 cents per ton, by the duty on foreign iron-ore; but this would certainly not be prohibitory in the case of a deposit sufficiently large, rich, and accessible. Or, to put it otherwise, there might easily be, somewhere in Canada, near our borders, a mine so favored that its product could be profitably

Jan 1, 1892

By P. Somasundaran, D. R. Nagaraj

Based on our finding that commercial copper chelating solvent extractants such as LIX65NR and LIX63R are excellent collectors for copper minerals, a detailed study was made using several water-soluble chelating agents belonging to the class of aromatic hydroxyoximes and having a gradual structural variation. A basic study of the system salicylaldoximetenorite was also carried out. Microflotation tests as a function of concentration of oxime, pH, addition of copper, etc., using oxidic copper minerals such as chrysocolla and tenorite, and batch laboratory flotation tests using synthetic mixtures of quartz and oxidic copper minerals were carried out. The results have demonstrated that the hydroxyoximes studied have comparable collector property, and in all cases the oxime was found to be partitioned between the mineral surface and the copper in the bulk aqueous phase in the form of a bulk copper chelate. The occurrence of the latter could be accounted for by formation in the bulk phase of a chelate between oxime and copper released from the mineral and/or by the detachment of the surface chelate. The role of surface and bulk chelates in flotation is discussed based on the results of partitioning of chelating agent into bulk and surface chelates in the salicylaldoxime-tenorite system. The effect of structural aspects such as isomerism and substitution in the molecule on the collector property of the oximes is also discussed. Substitution on oximic carbon by alkyl groups is found to promote collector activity. Only the anti-isomer has the ability to collect.

Jan 1, 1982

By Charles P. Williams

DURING the fall of the year 1873, attention was redirected to the occurrence of lead ores in Southwestern Arkansas (chiefly in Sevier County), and somewhat extensive explorations of the deposits have since been made in the hope of finding the ores sufficiently argentiferous to be profitably worked. How far the expectations have been realized I am not authentically advised, but samples of the galena ore, yielding 62.09 per cent. of lead, gave on assay at the rate of 15 3-10 ounces of silver to the ton of ore. This was the highest result obtained by myself, though I am informed that higher yields have been obtained by others. Among the samples of ores from this locality, forwarded to me in January last, was one specimen which I at once recognized as stibnite, and, on notification, other specimens of the same from Sevier County were forwarded me. The first specimen of the several received contained 11.51 per cent. of gangue, 57.62 per cent. antimony, 4.57 of bismuth, with small amounts of arsenic and iron. The latest result from a portion of another hand specimen I append in full, with duplicate estimations of the arsenic, bismuth, and gangue. The analyses were all conducted by Mr. C. R. Winters, under my direction, and in the case of those given below the ore was separated as closely as possible from the gangue before analysis. The results are for the mineral freed from hygroscopic moisture, and are as follows:

Jan 1, 1875

By Leon Y. Sadler, E. K. Landis

Froth flotation has been described by several authors" as being analogous to a first-order rate process. Although a few investigators"," have found orders other than one fit their data best, the rate is described most often by the first-order equation, [ ] where r is rate of disappearance of floatable mineral by flotation, C(t) is concentration of floatable mineral in the cell, t is time, and k is first-order flotation rate constant. One of the difficulties in using this rate equation to develop a mathematical description of an actual flotation process is the determination of a suitable value of the constant k. The value of k, which reflects the floatability of the floatable mineral, is dependent on the hydrodynamic conditions in the cell, type and concentration of flotation reagents used, pulp density, and pH, method of froth removal, aeration rate, particle characteristics, and many other factors. Therefore, it is reasonable to expect that each particle of floatable material has a distinct value of k and that a unique distribution of k values exists for given feed and cell conditions. This has been observed and discussed by several investigators, and mathematical descriptions of the batch cell and steady-state continuous cell with distributed flotation rate constant have been developed." The mathematical description in the form of a transfer function of the continuous or flow cell under unsteady-state conditions with a distributed flotation rate constant has not been presented in the literature. The purpose of this note is to make such a presentation. The basic features of the perfectly mixed continuous

Jan 1, 1974