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By J. S. Hromatko, L. J. Gurevich

In the course of the examination, at the BureLu of Standards, of fusible tin boiler plugs for the Steamboat Inspection Service, it became evident that an investigation should be undcrtaken to determine the precautions necessary in the manufacture of acceptable plugs. The results of the tests of these plugs show that their manufacture has improved, though at present not all of the plugs tested are, satisfactory. Table 1 gives the result of tests of some 1500 plugs from about 100 makers. Records of the tests show that several of the makers were able to produce satisfactory plugs with every pouring. The Steamboat Inspection Service has the following specifications for fusible plugs: "Fusible plugs for use in boilers of steam vessels under the jurisdiction of the Steamboat Inspection Service shall be made of bronze casing with the bore tapering continuously and openly from end to end, and filled from end to end with tin not less than 99.7 per cent. pure and to contain not more than 0.1 per cent. of lead and not more than 0.1 per cent. of zinc. The small end of the bore may be countersunk not more than 1/32 in. in depth and width, but no recess, thread, or cavity other than this countersink shall be allowed." Table 1.—Thirty-"five-mdh Testing Record of Fusible Plugs Causes of Rejection Inspection Period June-November, 1916.................. 311 32.8 47.2 3.8 11.5 15. 1 10.9 1 1.9 4.5 December, 1916-May, 1917............. 318 71.4 28.6 2.2 4.4 12.8 5.9 i ... 2.8 June-November, 1917.................. 228 73.0 27.01 ... 9.6, 5.2 9.6' ... 0.8 December, 1917-May. 1918............. 214 72.028.0 0.9 0.4 11.6 7.0 ... 7.9 June-November, 1918...............250 70.7 29.3 ... 2.0 20.0 5.2 ....2.8 December, 1918-April. 1919............ 23378.121.9 7.2 1.2 1 4.7 3.0 ... 6.0 Total 35 months....................1544.69.7 30.3 2.3 4.8 11 0 6.9 0.3 4.1

Jan 1, 1921

By AIME AIME

THE coal classification session* on Monday morning, Feb. 17, was opened by a paper by M. R. Campbell, entitled "Natural Groups of Coal and Allied Fuels," in which he pointed out, by means of graphical presentation of selected proximate analyses of coal, that coals can be classified on the basis of their moisture content. He proposes four groups of coal, brown coal, hydrobituminous, bituminous, and anthracite, each subdivided into two or three sub-groups. In a written discussion of this G. H. Cady, of the Illinois Geological Survey, showed that there is, in general, a progressive decrease in the moisture of Illinois coals from north to south, and that it would be very difficult to draw any arbitrary line dividing the coals of the State into two groups on the basis of moisture content.

Jan 1, 1930

By C. Laird, C. E. Feltner

An investigation into the effect of a material's slip character on its high strain fatigue properties has been carried out using copper and Cu-7.5 wt pct A1 as representative wavy and planar slip mode materials, respectively. In copper, the constant term and exponent in the Coffin-Manson equation, ?EpNf1/2 = const, are unaffected by the temperature of testing or the history of the metal. On the other hand, in Cu-7.5 wl pcl Al, while the exponent is invariant, the constant is increased with respect to copper and increased further with decrease in temperature. The life in Cu-7.5 wt pct A1 is double that of copper at room temperature and about four times at 78°K. Fractoflaphic studies indicate that these diffevences in life are associated with the early stages of cracking. In copper, severe surface rumpling provides crack nuclei at pain boundaries independent of' testing temperature or the history of the metal. In Cu-7.5 wt pct Al, the planar slip mode of deformation prevents grain boundary folding; crack nucleation is therefore mainly transgranular and the increase in life with respect to copper is associated with a prolonged linking-up stage of such transgranulay cracks. At the lower temperature the increased difficulty of cross slip inhibits multiplication of trans-granular cracks and retards the linking-up process, giving a further enhaancement in life. It is expected that such behavior will be found general in materials of wavy and planar slip mode, respectively. STAGE II crack propagation in high strain fatigue takes place by a repetitive process of crack tip blunting in the tension part of a fatigue cycle followed by resharpening of the crack in the compression part.1-3 This mechanism has come to be called the "plastic relaxation process".3 At very high strains (lives to failure less than 103 cycles), most of the life of a specimen is spent in crack propagation by the plastic relaxation process.4,5 Since the differences in the cyclic strain hardening behavior of metals and alloys are comparatively small in this strain range,6,7 the amount of blunting at a crack tip depends primarily on the applied strain amplitude. The rate of crack propagation in this life range is therefore nearly constant with respect to material and temperature of testing. In the longer life portion of the high strain fatigue range (l03 to 103 cycles to failure), a considerable fraction of the lives is spent in crack initiation and Stage I growth. Grain boundaries have frequently4,5,8 been found to be the sites for this growth which is also associated with a surface folding process.4'5 Such folding behavior may also be general in any material having a grain structure and capable of plastic deformation. It has therefore been suggested475 that the universality of the Coff in-Manson law,9'10 constant,* where ?Ep is the plastic strain range and Nf the number of cycles to failure, is reflected in the approximate invariance of both the crack initiation and propagation behavior. It happens that, in most investigations of the phenomena associated with failure,4,5,8 materials with a wavy slip mode have been used as vehicles for the studies, or else "normally" planar slip mode materials have been tested under conditions giving rise to wavy glide deformation, e.g., stainless steels cycled at high temperature.'' The purpose of the present investigation was to determine whether or not different cracking phenomena would occur when the slip mode of a material is planar and if the associated life to failure would be different than that of a wavy slip

Jan 1, 1968

By W. F. Rogers, J. A. Stewart, P. J. Kalish, E. O. Bennett

Detailed descriptions are given of materials, apparatus and the experimental procedure used to study the effect of bacteria on sandstone permeability. The factors affecting permeability during injection of bacterial suspensions which have been investigated are: (I) concentration of bacteria; (2) core permeability and median pore size; (3) species of bacteria, mode of aggregation and relative size; (4) injection rate or pressure differential; (5) mean pressure; and (6) depth of penetration of bacteria. The investigation demonstrated that bacteria cannot reduce core pertneability to zero and that their effect on permeability is subject to definite limitations. Remedial or permeability restoration studies also were made. Acidization in combination with reverse flow war found to be an effective method for restoring permeability In cores partially plugged with bacteria. The relationship between the bacterial quantities in the laboratory tests and those found in field operations is discussed. The linear laboratory flow data have been translated into terms of field radial systems; these data indicate the most practical methods of maintaining injection rates in the presence of bacteria are to increase injection pressures or hydraulically fracture the formation. INTRODUCTION It has long been known that various bacteria flourish in the above-ground components of oil field water-injection systems. The presence of these bacteria has led to the suspicion that they might enter into the causes for reduction of injection well permeability, but only recently has an attempt been made to describe the effects quantitatively.1 Biocides are used in many cases without a firm knowledge as to whether the bacteria are killed, or if they are, whether the dead cells affect formation permeability. This project was undertaken as part of a study to determine the effect of bacteria, residual oil and precipitated solids such as iron sulfide or calcium carbonate on the permeability of sandstones and to learn whether any of these materials adversely affect brine injectivity in secondary recovery or disposal operations. This report deals with that portion relating to the effect of bacteria. MATERIALS CORES Three different permeability ranges of Berea sandstone cores were used in the study. The range of initial, absolute brine permeabilities kj were: high — 278 to 400 md: medium—130 to 162 md; and low—17.7 to 48.3 md. The permeability data for the cores used in the tests are included in Table 1. All cores were cut to a nominal 1 in. diameter. Following air permeability determinations, they were molded with an epoxy resin in 1.5 in. ID aluminum sleeves. The sleeves had drilled and tapped holes for intermediate pressure connections along the length of the cores. After molding, the high- and medium-permeability cores were trimmed to 4 in. in length and the low-permeability cores to 2 in. These lengths resulted in pore volumes of approximately 10.9, 10.4 and 4.4 ml, respectively, for the high-, medium- and low-permeability cores. Pressure-transmitting channels were drilled through the plastic into the core proper, using the sleeve holes as drill guides. Width and depth of channel penetration into the core proper were approximately 0.03 in. and 0.05 in., respectively. Three pressure taps were used with all cores; for the high- and medium-permeability cores the taps were spaced 1 in. apart; for the low-permeability cores the taps were spaced 0.4, 0.8 and 1.2 in. from the inlet end. Pore size distributions were calculated from restored-state capillary pressure curves for representative cores in each of the three permeability ranges. In each case the pore size range with the greatest percentage of the pore space included the very small pores up to 0.5 micron in radius. The median pore radii were in the 5.5 to 6 micron range for the high-permeability cores; in the 4.5 to 5 micron range for the medium-permeability cores; and in the 3.5 to 4 micron range for the low-permeability cores.

Jan 1, 1965

In discussing Mr. Keller's paper, I quoted the results obtained by Mr. Allan Gibb, correctly crediting them to Mr. Gibb, with due reference to the report in which they were published. But in the table immediately following, and in my further remarks, following the table, I find that, by some clerical or other error which I cannot, after the lapse of time, explain, I spoke of Mr. Gibb as Mr. "Dean"—a metallurgist who had written on a related subject, but not on the point I was discussing. In short, my reference throughout was to the work of Mr. Gibb; and by reading a Gibb " for a Dean " in all places on pp. 832 and 835 where the latter name occurs, my remarks will be brought into accordance with my intention, and with the facts.

Jan 1, 1901

By Herbert Clark Hoover, Lou Henry Hoover

MANY persons hold the opinion that the metal industries are fortuitous and that the occupation is one of sordid toil, and altogether a kind of business requiring not so much skill as labour. But as for myself, when I reflect carefully upon its special points one by one, it appears to be far otherwise. For a miner must have the greatest skill in his work, that he may know first of all what mountain or hill, what valley or plain, can be prospected most profitably, or what he should leave alone ; moreover, he must understand the veins, stringers1 and seams in the rocks2. Then he must be thoroughly familiar with the many and varied species of earths, juices3, gems, stones, marbles, rocks, metals, and compounds4. He must also have a

Jan 1, 1950

By Toshimitsu Kokubo, Yoshio Yamagata, Tadao Moro, Kenji Tomita

Owing to the traffic jam in collection, and transportation of wastes, the air- and water- pollution in incineration plants, and the sanitary trouble in reclaimed land, it seems that the defective existing system of the solid waste treatment in Japan can not follow the change in quality and the increase in quantity of solid wastes. Under these situations, the objective of the municipal solid waste treatment must be to actualize the pollution-free system for environmental protection and the resources recovery system for resource- and energy- saving. From this point of view, AIST of Japan is now engaged in the research and development of the resources recovery system from municipal solid wastes. This paper reports on the outline of the development of resources recovery technology in Japan, including the AIST's project on this matter.

Jan 1, 1976

By E. A. Hartsook

Since World War II we have all been treated to repeated public and private evaluation of the population explosion. Improvements in medicine and agriculture have brought greater life expectancy and a decreasing infant mortality rate. This has brought boom conditions to some areas-and pressures everywhere for the amenities of life: a little elbow room, a tree or a pot of flowers, space to hike or swim with some freedom have all become premium commodities. With this wish for privacy and attractive surroundings, people are being forced to move to once sparsely populated areas. Suburbs expand or sprawl, depending on the point of view. New country is touched by a freeway and houses and stores spring up overnight. Entire new cities are born to meet the increasing mobility of industry and its work force.

Jan 6, 1965

IT has been discovered by skilled bell founders, more through experience than from geometrical calculation (although calculation does enter), that a certain relationship of dimensions in both large and small bells makes the tone and the weight almost certainly what is desired. This is in addition to the customary shape which is, according to the historians, perhaps that found by the first discoverers of bells. Among themselves bell founders have made a rule of these measurements and have called it the bell scale. Beginning with the small ones weighing ten pounds, it increases by degrees to a point where, as I have seen, they are able to make them even twenty-five and thirty thousand pounds. This scale is of great enlightenment if one does not have a bell already made for comparison.

Jan 1, 1942

By E. E. Carpenter

(San Francisco Meeting, September, 1915) BELIEVING that the results accomplished in the mill of the Churchill Milling Co., Wonder, Nev., during the fiscal year ended Sept. 30, 1914, will be of interest, I am presenting the more prominent facts and figures showing the progress made in treating this ore with especial reference to tonnage, supplies, costs, and extractions. The mill is situated at Wonder, Nev., in the Wonder mining district, 55 miles east from Fallon, Nev., the nearest railroad point. All supplies are hauled this distance by freight teams, this method of transportation having been found more reliable for continuous service than trucks, the price paid for hauling being slightly under one cent per pound. In this mill are treated the ores of the Nevada Wonder Mining Co. ,

Jan 6, 1915

By Nicholas M. Short

Many a geologist or driller has wished he could somehow climb into a borehole to see for himself what fractures looked like. Or why recovery was poor. Or how the bit was actually lost. Now it is possible to do the next best thing to climbing into the hole. TV cameras are being used for a close-up look at borehole conditions. Ever since television was invented, geologists and others interested in subsurface conditions have wanted a TV camera that could be used in the narrow confines of a borehole. But development of such a camera was slow, mainly because of the need for compact size. Not until the late 1950's did the technology of electronic miniaturization develop to a point where a camera satisfactory for the purpose could be put together.

Jan 1, 1963

By J. Ehner Thomas, M. D. Gould

Until four years ago the market price of oil securities moved directly and immediately with the general list. This point, was first developed by the senior author in 1924 while making a statistical study of the relative movement of oil securities and the general market. Plotting the monthly averages of 17 oils against 233 industrials disclosed the sur- prising relationship shown in Fig. 1. The traditional vagaries of the oil business, the wide fluctuations in current supply and resulting abrupt changes in crude prices nevertheless produced no movements in the market price of oil securities as a group, which departed notably from the movements of the general market. Obviously general business conditions did not always change when and as conditions in the oil industry changed; clearly the fluctuations of

Jan 1, 1929

By John S. Alexander

DURING the past few years the block coal of Indiana has been talked about and written upon to such an extent, that almost every one at all interested in such subjects, has been made acquainted with the area and geographical position of the field, the quality and peculiar properties of the coal, the thickness of the veins, the manner of mining, etc. The writer, therefore, taking for granted that, to those present all this is familiar ground, desires more especially to call attention to the position this coal takes in the market, and at those points of consumption where it is brought in direct competition with rival fuels. Chicago, thus far, has been the chief consumer of Indiana block coal, the distance from the mines at Brazil, via Terre Haute and the

By John S. Alexander

DURING the past few years the block coal of Indiana has been talked about and written upon to such an extent, that almost every one at all interested in such subjects, has been made acquainted with the area and geographical position of the field, the quality and peculiar properties of the coal, the thickness of the veins, the manner of mining, etc. The writer, therefore, taking for granted that to those present all this is familiar ground, desires more especially to call attention to the position this coal takes in the market, and at those points of consumption where it is brought in direct competition with rival fuels. Chicago, thus far, has been the chief consumer of Indiana block coal, the distance from the mines at Brazil, via Terre Haute and the 25

Jan 1, 1873

By Richard Pearce

WHILST most of the silver- and copper-bearing veins of Butte have characters somewhat similar, the Gagnon vein has certain rather remarkable features which are not noticed in any of the other mines. The silver-veins proper, as illustrated in the Alice, Lexington, Moulton, and many others, have certain well-known typical characters. Manganese is always present in variable quantities as rhodocrosite or rhodonite, associated with quartz, pyrite, and sphalerite, and with little or no copper. The copper-veins also have certain mineralogical characteristics, which are very similar, or different only in minor points. Chalcocite, chalcopyrite, bornite, enargite, with variable quantities of pyrite, may be said to represent the general mineralogical features of these lodes. It is worth noticing that while the silver-bearing lodes have more or less sphalerite, this mineral is almost entirely

Jan 1, 1888

Charles T. Malcolmson, Chicago, Ill.:—Mr. Blauvelt's admirable paper is a valuable contribution to the literature on briquetting of coal in this country. It should have a special significance for those interested in the commercial development of the coal-briquette industry. I believe that the data included in Mr. Blauvelt's paper will be particularly useful because they represent costs taken from a briquette-plant in actual operation. There are several points touched on in Mr. Blauvelt's paper which may bear comment in the way of emphasis rather than of criticism. In the first place, he has stated a fact which becomes axiomatic to any one who has had any experience in the design, building, or operation of coal-briquette plants, and that is, that the press is only one factor in the successful opera-

Jan 1, 1911

By Robert C. Emmett, Donald A. Dahlstrom

FOR many years gravitational classification has been employed as a basic tool in beneficiation of minerals and coal. While improvements have been made to increase efficiency and fields of application, the basic flow pattern has remained relatively unchanged in most gravitational classifiers. Feed slurry is introduced into a settling pool wherein the coarser solids settle against either an upward or horizontal fluid current, or a combination of both, and are withdrawn in a concentrated underflow stream. The finer solids below the classification point possess too low a settling velocity and thus are primarily swept out through a weir overflow by the bulk of the fluid. Because of its simplicity, efficiency, and low power and maintenance costs, gravitational classification finds a wide acceptance for separations in the range of 20 to 325 mesh.

Jan 10, 1953

By K. C. Ko, M. K. McCarter

Experimentation with seismic velocity measurements at Kennecott Copper Corp.'s Bingham mine disclosed that some recognized slide areas are characterized by low velocity profiles. A new traverse technique employed during the investigation allows rapid and precise measurements of a quantity referred to as "apparent velocity." This value is a weighted average of the actual velocity in the overbreak zone near the surface and in the intact rock at depth. The low points on the velocity profile are apparently the result of lower actual velocities and deeper overbreak in less competent material within the slide zones. Experience verifies the usefulness and practicality of the technique in delineating adverse areas prior to detectable failure. The technique may be employed as a rapid and economic means of slope stability surveillance in large open pit mines.

Jan 1, 1973

THE term mountain bump describes the sudden rupture of one or more coal pillars under excessive stress. These bursts occur with varying degrees of violence and sometimes include adjacent strata, especially the bottom rock. Many failures do not develop enough violence to be dangerous and are regarded as an aid to coal production, but severe occurrences are accompanied by tons of flying coal, dense clouds of dust, and excessive gas emission. Such bursts sometimes throw heavy machinery several feet. Major factors to be considered in the problem are the nature of the strata above and below the seam and the depth of cover. Bumps are classified as to their nature, extent of damage, and point of occurrence, e. g., face bump, coal bump, high side bump, low side pavement bump, and district bump.

Jan 8, 1958

By T. F. Witherbee

The subject of an article in the Engineering and Mining Journal for October 13th, 1877, namely, Blast Furnace Treatment of Silicious Iron Ores,, is of great interest to myself, and doubtless to many others who hare been troubled with a seemingly unaccountable percentage of silicon in their pig iron. It is to be regretted that the author of the article did not give us complete details of his charges, and thus prevent a possibly fatal error in the very beginning of the discussion of the points raised in his communication. As it now stands, I think we will have to fall back upon the statement that, " every conceivable mixture of fluxes and ores (A and B) has been used." Let us first, in order to simplify the calculations, do with she

Jan 1, 1879