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By T. H. Chin, R. W. Bartlett

A simple on-stream particle-size analysis method is presented that leads to a bulk-property single-channel device; although the concept can be extended to multi-channel sizing information. The method is based on continuously measuring and comparing the percent solids in the sample stream and in an internal-reference stream containing only undersize particles. A semipermeable hydraulic system is used such that the particle mass concentration in the internal stream can vary, and is always proportional to the undersize particle mass concentration in the sample stream.

Jan 1, 1975

By C. Hirayama

THIS investigation was undertaken to determine some of the factors contributing to the embrittle-ment of glass-coated silver wire on heat treatment. The materials used in this investigation were 22 and 23 AWG silver wires obtained from Handy and Harman as "fine quality, soft temper." A wet analysis of one sample showed 99.8 pct Ag. The 23-gage wire was covered with a double layer (2.5 mils thick) of electrical grade fiber glass (aluminum borosilicate glass containing a relatively high concentration of calcium, and a very small amount of

Jan 1, 1960

As a means of lending weight to the activities of its Committee on Industrial Organization, with particular reference to the work on mental hygiene and the prevention of illness, the Institute has recently invited a number of members of the medical profession to become Associates of the Institute. We are glad to observe that the wisdom and utility of this departure have been appreciated by the gold mining industry, in testimony whereof we are pleased to publish the accompanying sketch from the pen of Mr. P. A. Robins, Managing Director of the Hollinger

Jan 8, 1918

By Lawrence Adler

Any design of a mine roof in bedded deposits which ignores differential deflections at the supports can quickly lead to dangerous overstressing. As illustrated by the typical case presented on page 1029, if one support deflects only 0.1 in. more than its neighbor, stresses 50 pct higher than anticipated will result. Previous studies1-3 have assumed that the mine roof acts like a beam clamped at both ends, with no deflection or slope4 at the supports (Fig. 1). Essentially this assumes:5,6 [BA = OD = 0 and dA = dB = 0.]

Jan 10, 1959

By Oswald J. Heinrich

In conclusion of a series of deep exploration-borings with the diamond drill, I beg to submit the following statements, supplementary to those in my former papers on this subject: Since my communications read at the St. Louis Meeting, in May last, I have finished two more borings, one terminating at the depth of 922 feet 7 inches, the other at the depth of 715 feet 6 inches. The results in regard to time and expenditure have been highly favorable and fully confirmatory of my opinion stated in previous

By Oswald J. Heinrich

(Supplementary Paper.) IN conclusion of a series of deep exploration-borings with the diamond drill, I beg to submit the following statements, supplernentary to those in my former papers on this subject: Since my communications read at the St. Louis Meeting, in May last, I have finished two more borings, one terminating at the depth of 922 feet 7 inches, the other at the depth of 715 feet 6 inches. The results in regard to time and expenditure have been highly favorable and fully confirmatory of my opinion stated in previous

Jan 1, 1875

By Nancy S. Brodsky

A specimen of Westerly granite was cyclically loaded to near failure at 50 MPa confining pressure. Holographic interferometry provided detailed measurements of localized surface deformations during loading and unloading. The data are consistent with deformation occurring primarily elastically at low differential stress; in conjunction with one incipient fault zone between approximately 350 and 520 MPa differential stress; and in conjunction with a second incipient fault zone above 580 MPa and/or during creep. During unloading only one fault zone, that which is active at the intermediate stress levels during loading, is seen to recede.

Jan 1, 1984

By Renato G. Bautista, Gary A. Beetner, Anthony L. Frey

A multistage mixer-settler extractor described in earlier hydrodynamic studies was simulated on a computer. A mass transfer mechanism was derived based on a pseudo distribution constant and a pseudo first-order rate constant. The constants were adjusted to give the proper output concentrations and proper form of the stage-wise concentrations. The results obtained by computer simulation of start-up conditions show very good agreement with experimental data. A second simulation was constructed which demonstrated that the model can be greatly simplified and still yield good results.

Jan 1, 1974

By William E. Ford, Edward Salisbury Dana

239, Contact-Gwiorneters. - The interfacial angles of crystals are measured by means of instruments which are called goniometers. The simplest form is the contact- or hand-goniometer one form of which is represented in Fig. 377. This contact-goniometer consists of a card on which is printed a semi- circular arc graduated to half degrees at the center of which is fastened a celluloid arm which may be turned to any desired position. The method of use of the goniometer is illustrated in Fig. 377. The bottom of the card and

Jan 1, 1922

By Robert C. Bolger, John H. Weitz

REFRACTORY clay, one of Pennsylvania's important nonmetallic mineral resources, occurs at several horizons in beds of Pennsylvanian age. The Mercer fireclay, of Pottsville age (Table 1), is the most important of these clays. A study of this fireclay has been conducted by the Pennsylvania Geologic Survey discontinuously over a period of seven years. The work has included field mapping of a rather large area, as well as petrographic, differen¬tial thermal, and X-ray studies of the fireclay. A comprehensive report on the project is now in preparation.

Jan 1, 1952

By P. C. Hodges

While there is very little romance connected with the operation of a stone quarry, yet to those who have participated in the growth and development of a business that has been a pioneer in its field and that has been in continual operation two-thirds of a century there is bound to be a background of experience, which if properly capitalized, brings progress as well as satisfaction in its accomplishment. The simple methods of drilling and blasting limestone and loading on to railroad cars everything that remained on a stone fork and leaving

Jan 1, 1936

By P. C. Hodges

While there is very little romance connected with the operation of a stone quarry, yet to those who have participated in the growth and development of a business that has been a pioneer in its field and that has been in continual operation two-thirds of a century there is bound to be a background of experience, which if properly capitalized, brings progress as well as satisfaction in its accomplishment. The simple methods of drilling and blasting limestone and loading on to railroad cars everything that remained on a stone fork and leaving

Jan 1, 1936

By T. S. Fuller

THE experiments described in this paper constitute the preliminary work of an investigation outlined to determine the combined effects of steam and temperature on the endurance properties of certain steels. Essentially of a fundamental nature, it was found necessary, in order to make the investigation comprehensive, to test materials treated to give a wide range of properties. The work reported deals chiefly with nickel steel with one series of tests including nitriding steel. Such a study involves numerous variables, and requires an endurance-testing machine of rather special design.

Jan 1, 1930

By Alfred E. Hunt

Tars paper is suggested by the appointment on the part of the American Societies of Mechanical and of Civil Engineers of committees upon the subjects of " Standard Tests and Methods of Testing," and " Uniform Methods of Tests of Material used in Metallic Structures," respectively, and by a study of the report of one of these committees, and other papers. Moreover, the writer has had frequent occasion to hear the complahts of tnanufacturers who furnish structural material subject to specifications, that in the tests prescribed, the number of tests required, and the methods of making

Jan 1, 1892

By Nev A. Gokcen

DISCREPANCIES and scattering in the equilibrium data on the reactions of hydrogen, and CO with dissolved oxygen in liquid iron are un- duly large. Available experimental results on the reduction of liquid ferrous oxide, i.e., wüs-tite, with hydrogen and CO are questionable, as pointed Out by Darken and Gurry'l Direct determinations of the solubility of oxygen in liquid iron are subject to errors which cannot be easily reduced by further experimental refinements, and therefore an accurate but indirect method is highly desirable. The purpose of this investigation was, therefore, 1)

Jan 1, 1957

By Earl Oliver

Some two years ago the Petroleum Division of the A. I. M. E. organized a special study of unit operation. That method of handling oil pools had been urged as the remedy that would save the United States petroleum industry from the crisis that even then loomed as more than a small cloud on the horizon. Today it is only one of several remedies vigorously advocated. Proration, regulation of imports, unit operation, constructive marketing and interstate compacts all have their earnest proponents, but the advocates of each have been disposed to look with indifference on the other respective proposals, with the result that none has had united support. Meanwhile the industry has drifted rapidly toward a serious crisis, the imminence of which in itself may bring the solution. The gravity of the situation tends to force study of the merits of proposals that a short time previously were brushed aside as impractical; and to the surprise of most of us we now find merit where previously we thought none existed. Irrespective of what might have been the result had any single proposal being adopted years ago, it is now apparent that under present conditions no one of the remedies—unit operation, proration, regulation of imports or constructive marketing—standing alone would be of much benefit. On the other hand, it is becoming evident that a well balanced program comprising all four of these remedies might save the United States petroleum industry; also that some such comprehensive program might be necessary to save it. It is even becoming evident that the despised interstate compact might be an appropriate type of machinery in which to group and coordinate all these remedies. We have progressed beyond the belief that either the industry or the government working alone can correct the situation, and have arrived at the more healthy realization that the task will require most sympathetic cooperation between government and industry, backed by an equally sympathetic public understanding. If we were functioning under a Mussolini or a Stalin, stabilizing the petroleum industry would be a much simpler task. However, in the

Jan 1, 1931

By A. S. Eve

IN the spring of 1930, the question was raised as to the possibility of estimating the depth to which the pyrrhotite-nickel deposit at the Falconbridge mine extended in the earth. This body is 7500 ft. long, it dips at 80° to the north, and it is fairly straight with slight sinuosities. Dr. F. W. Lee suggested that it might be possible to solve the problem by measuring the vertical magnetic intensity, with a good magnetometer, both near the surface of the earth and also at a level a 'few feet higher in the air. The writer regarded this suggestion with some scepticism, but it was decided to put the scheme to a prac¬ tical test. In July, 1930, Dr. Lee, Dr. Keys and I ' the writer, with Mr. Joyce and Mr. Belloc as assist¬ ants, made a firm, light wooden platform (Fig. 1) E measuring 4 by 4 ft. on the top, which was 10 ft. above ground. This platform could be moved easily a few yards by four men, and carried across I country in a wagon or by motor truck. Some iron nails were used in its construction, but we were not able to detect their influence on the - Askania magnetometer. Nevertheless, in future work, the use of iron should be completely avoided. Readings were taken along a traverse at right L angles to the orebody, at several stations, both on FIG. 1.-VERTICAL the ground and on the platform. The excess read- ASKANIA MAGNETOM¬ ETER ings, over the dike, as compared with those about 10 ETER ON A FT. HIGH. PLATFORM 800 ft. away, are shown in Table 1. The largest reading, 6.8, is open to suspicion and should be rejected. The depth of the top of the orebody is known by electrical survey, and by actual drilling, to be about 112 to 123 ft., and the covering is sandy glacial drift. Similar readings were taken over a long straight magnetic diabase dike. These also are shown in Table 1. The magnetic vertical intensity is consistently less at the higher level, which is l0 ft. above the lower level.

Jan 1, 1931

By C. G. Brehm

The anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal measures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof support and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches. The Lower, or Southern field, is made up of basins of great depth, some being 4000 ft. deep, and its measures are mostly on very steep pitches. In certain sections this Southern field is being mined at an elevation of 1300 ft. below sea level, on a pitch ranging from 50' to practically vertical, and because of the tremendous pressure and the inherent gas in the seams, outbursts of coal frequently occur at the face, locally known as "bumps." These outbursts are accompanied by a rumbling noise, after which gas is usually found. This condition makes mining a difficult and extremely hazardous undertaking, and unusual skill is required on the part of the miner to drive and maintain openings necessary to the production of coal. Miners working in such seams on the heavy pitch must carry face batteries (Fig. 1) to afford proper protection while working at the face, because of the outbursts and free running coal. To drive haulageways or gangways in this field it is

Jan 1, 1940

By C. G. Brehm

The anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal measures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof support and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches. The Lower, or Southern field, is made up of basins of great depth, some being 4000 ft. deep, and its measures are mostly on very steep pitches. In certain sections this Southern field is being mined at an elevation of 1300 ft. below sea level, on a pitch ranging from 50' to practically vertical, and because of the tremendous pressure and the inherent gas in the seams, outbursts of coal frequently occur at the face, locally known as "bumps." These outbursts are accompanied by a rumbling noise, after which gas is usually found. This condition makes mining a difficult and extremely hazardous undertaking, and unusual skill is required on the part of the miner to drive and maintain openings necessary to the production of coal. Miners working in such seams on the heavy pitch must carry face batteries (Fig. 1) to afford proper protection while working at the face, because of the outbursts and free running coal. To drive haulageways or gangways in this field it is

Jan 1, 1940

By W. P. Haseman

The well method of producing oil and gas is universally used in the development and operation of oil and gas properties. It consists essentially in the spacing of a number of wells on a given tract, and in drilling and operating them in accordance with established practices. The method is based on a fundamental energy principle. This principle governs the state and the change of state of fluids or fluid mixtures confined under pressure within a porous and permeable reservoir in such a way as to direct a flow from the reservoir into and out of a drilled well with a reduction of potential energy. The application of the well method of producing oil has given data which prove that the total yield of oil from a reservoir through wells is, in general, only a small fractional part of the total oil that is contained in the reservoir. It is generally recognized that a spacing of one well to each 160-acre tract of any good oil pool is too wide. However, one well to this 160-acre tract will yield a large quantity of oil and in time will dissipate most, if not all, of the potential energy that was originally stored and retained in the fluids by pressure. Two wells spaced and drilled on this 160-acre tract would yield approximately twice the quantity of oil, while four wells would yield approximately four times the oil. A well spacing is soon reached, with the addition of wells to this 160-acre tract, in which the drainage interference of offset wells will materially affect the yield of oil per well. The increased yield of oil, therefore, is not directly proportional to the added number of wells but the increased costs of development are directly proportional to the added number of wells. It is evident that while an added number of wells to this 160-acre tract yields an increased quantity of oil, there is an economic limit to the number of wells to be added. The yield of oil and the costs of development and operation are of such a nature, and are so related, that

Jan 1, 1930