bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stabilizing a Suction-Relief Valve
Authors: Smith Ed S. 
Published: December 2022

Abstract
Starting with a less than fully stable conventional valve in aircraft use, a simple analysis is presented which is based upon energy considerations under resonance conditions and involves a minimum of mathematics. This analysis led to the disclosed improvement which renders the valve stable under all installations except the worst, from an acoustic standpoint. A short appendix on acoustic systems is included for the convenience of control engineers who may need in advance to evaluate and, if necessary, correct acoustic difficulties of installations. The analysis of this paper amounts to an informal use of the Nyquist method.
Lubrication Characteristics of Involute Spur Gears: A Theoretical Investigation
Authors: Gatcombe E. K. 
Published: December 2022

Abstract
In this paper the lubricating-oil wedge which separates the tooth surfaces of involute straight spur gears is analyzed mathematically. Expressions are derived for the pressure distribution, the maximum pressuro, the minimum thickness, and the load-carrying capacity of the wedge for any phase of mating. The equation for the load-carrying capacity may give guidance to gear designers and to gear operators who are conscious of the importance of lubrication in their fields of work.
Silica Deposition in Steam Turbines
Authors: Straub F. G. , Grabowski H. A. 
Published: December 2022

Abstract
Laboratory and power-plant tests have been conducted to determine the cause of silica deposition in steam turbines. The tests indicate that the silica leaves the boiler as vaporized silicic acid which later crystallizes on the blades in the lower-pressure stages of the turbine. When the silica in the steam is below 0.1 ppm, no appreciable deposits are found in the turbines. Two methods of preventing deposits are suggested; (1) maintain the silica in the boiler water below 5 ppm; (2) remove the silica from the steam by scrubbing with a pure-grade water.
History of Potassium Boiler-Water Treatment at Springdale
Authors: Hankison L. E. , Baker M. D. 
Published: December 2022

Abstract
Results are given in considerable detail of 2 years’ experience in the treatment of boiler water at Springdale Station, West Penn Power Company, with potassium compounds which were substituted for sodium salts for water conditioning of both the high- and low-pressure boilers. This change in treatment was started August 25, 1942, in an endeavor to prevent the formation of silica scale in the boilers and also to minimize if possible deposits of silica on the turbine blades.
Water-Hammer Analysis by the Laplace-Mellin Transformation
Authors: Rich G. R. 
Published: December 2022

Abstract
The author supplements the pioneer work of Prof. F. M. Wood in applying operational methods to the study of water-hammer phenomena. The Heaviside calculus is replaced by the Laplace-Mellin transformation together with the elementary theory of functions of a complex variable. This substitution facilitates interpretation of a much wider range of operators, is believed to be better adapted to problems starting from a steady-state system in motion, and permits working directly with total pressures and velocities instead of surge pressures and velocities. This third feature operates to eliminate ambiguity concerning reflection coefficients at junction points in branched-conduit problems. When the effect of friction is not included, results are given in the form of simple trigonometric series of rapid convergence. When the abscissas of the two terminal sections of the conduit are inserted in these formulas, the resulting expressions are, in many cases, Fourier representations in the time variable of well-known periodic step or saw-tooth functions. In such instances, almost no computation work is required; it is unnecessary to sum the series, as the value of the summation may be taken at a single reading from a graph of the function, one plot of such a function serving for all particular cases within its domain. In cases where the effect of friction is included, a standard table of Bessel functions, used in conjunction with the formulas developed, affords easy and comparatively rapid solution.
Use of Anthracite Fines in By-Product Coke Production: Factors Influencing the Relative Suitability of Different Anthracites for Blending
Authors: Clendenin J. D. , Barclay K. M. , Wright C. C. 
Published: December 2022

Abstract
The blending of carbonaceous materials, particularly Pennsylvania anthracite, with coking coals as a means of mitigating the acute war shortage of certain types of metallurgical coke, has received considerable emphasis in recent months. However, the desirability of blending anthracite fines with coking coals for by-product coke production has been a matter of considerable controversy. To settle the differences of opinion and judgment, an attempt has been made as reported in this paper to evaluate, at least relatively, some of the variables encountered in the case of anthracite fines. The investigation in question was conducted at the Mineral Industries Experiment Station of The Pennsylvania State College, and was sponsored jointly by the Anthracite Institute and the Commonwealth of Pennsylvania.
Blending Coals Reflects Greater Uniformity of Product
Authors: Stilwell R. F. 
Published: December 2022

Abstract
Coal consumers look for three qualities in their fuel, suitability for their requirements, uniformity in shipments, and proper heating value, as well as suitable chemical and physical characteristics. The present paper gives a broad picture of the part that blending plays in the attainment of these qualities, discussing methods and equipment which have given the best results. Case examples are cited of the improvements achieved by suitable blending practices. Metallurgical engineers have had much wider experience in blending raw materials than have coal-preparation engineers; and the author has incorporated notes on “bedding” or blending with reference to coal, by A. J. Boynton, an authority on the subject. Suitable bin designs for blending purposes are included in the paper.
Prediction of Centrifugal-Pump Performance
Authors: Pigott R. J. S. 
Published: December 2022

Abstract
The author states that the selection of impeller, diffuser, and volute shapes of centrifugal pump designs are largely empirical, because the theory, based mostly upon the classical centrifugal theory, has been incorrect or at least incomplete. In the prediction of performance of small multistage deep-well pumps, some time ago, the author found another course of analysis which gave promise of excellent results. Essentially, the centrifugal pump does not operate as such except at shutoff but does behave as a radial-flow turbine. Consequently, the performance can be more truly analyzed and the hydraulic losses can be treated as if the pump were a pipe with a shock loss at the pickup edge of the blades and a recirculation loss. This method of prediction is explained and illustrated in the course of the paper.
A Study of the Theory of Axial-Flow Pumps
Authors: Wislicenus G. F. 
Published: December 2022

Abstract
The essential aim of this paper is to present the theory of axial-flow pump runners in as simple a form as possible. The results are fairly conclusive in so far as the determination of the flow conditions in individual cylindrical stream surfaces is considered. In addition, it has been found possible to eliminate the controversy between the one-dimensional and the two-dimensional theories. The question of the method to be employed in building up the performance of the machine as a whole is still controversial and has been presented in this form.
Efficiency of Extended Surface
Authors: Gardner Karl A. 
Published: December 2022

Abstract
The work of previous investigators on heat flow through extended surface is briefly reviewed and literature citations are given. General equations are derived for the temperature gradient and fin efficiency in any form of extended surface to which the assumptions listed are applicable. The solution of these equations in terms of Bessel functions is shown to cover practically any form of extended surface whose thickness varies as some power of the distance measured along an axis normal to the basic surface. Curves are presented for the fin efficiency of several forms of straight fins, annular fins, and spines.
Disk Extended Surfaces for High Heat-Absorption Rates
Authors: Tate G. E. , Cartinhour John 
Published: December 2022

Abstract
Four types of disk-on-tube extended-surface heat exchangers are discussed in this paper, i.e., interlocking castiron sections of nine disks each; die-cast aluminum-alloy disks each with shroud and hub; two surfaces die-pressed from wrought-iron sheet, each with a flue; and one a sixteen-pronged star. Data for both the cast-iron and aluminum surfaces were obtained from tests of full-sized economizers in conjunction with boiler tests, while data on the wrought-iron disks were obtained from laboratory studies. Details are given of the testing procedure, and the results in terms of effectiveness of the various surfaces are analyzed and correlated.
Gasoline Explosion Pressures
Authors: Plesset M. S. , Gilmore F. R. 
Published: December 2022

Abstract
A numerical method is outlined which permits the calculation of the temperatures and pressures obtained when mixtures of air and aviation-gasoline vapor are exploded in a closed chamber. The calculations use basic thermo-dynamic data to determine the final equilibrium state of the air and gasoline mixtures after combustion. Similar calculations have been carried out previously by other investigators, but only for a limited range of mixture ratios. Experimental measurements of the explosion pressures were made using an explosion bomb with a strain-gage pressure pickup. The measured pressures were of the same order of magnitude as the calculated pressures, but in general were somewhat above the theoretical values. Some possible explanations for this trend are discussed in the text.
Heat Transfer From a Cylindrical Surface to Air in Parallel Flow With and Without Unheated Starting Sections
Authors: Jakob Max , Dow W. M. 
Published: December 2022

Abstract
The present investigation sponsored by the Illinois Institute of Technology, Armour Research Foundation, and Institute of Gas Technology, deals with the heat transfer of air in parallel flow to a surface, a process of great practical importance which, for instance, occurs with all kinds of fins or on the skin of an airplane in flight. Previous knowledge of that process was based on a few sets of experiments which were performed with plane surfaces and led to a considerably higher heat transfer than a reliable theory, due to H. Latzko. In particular, the influence of nonheated starting sections seemed to require a new investigation. Compared with the use of plane plates by previous investigators, the use of an electrically heated cylindrical specimen has the following advantages: A cylinder can be easily placed in the center of an air jet and is free of the edge losses of a plate; for both reasons, air jets of moderate diameter can be used. Uniform heating is easier to provide, heat losses to the back are easier to control, and noses of different shape and cylindrical starting sections can readily be used for studying the behavior of the so-called boundary layer of the fluid which is developing along the surface, first streamlined and then turbulent, and in which all resistance against heat transfer is concentrated. The experiments were performed with specimens of 1.3 in. diam and 9 to 20 in. total length, the ratio of the heated length to the total length being varied from 40 to 90 per cent. Spherical, ellipsoidal, and conical nosepieces were used. The air velocity was varied from 10 to 150 fps and it is assumed that the results can be theoretically extrapolated above sound velocity, using the principle of similarity.
Some Effects of Work Positioning When Face-Milling Steel
Authors: Lucht Fred W. 
Published: December 2022

Abstract
All of the work that has been done and all of the observations which have been made to date on the subject of face-milling steel with carbide cutters have indicated clearly that the longest cutter life is obtained when (1) the cutters have double negative rake angles, and (2) the full depth of cut is taken along some definite corner angle. Until recently, not much thought had been given to the positioning of the work in relation to the cutter, and only in limited cases has any consideration been given to the fact that the radial engagement angle between the face of the tooth and the edge of the work where the cutting edge enters it should be negative. Milling operations are frequently found where the diameter of the face mill is too small to permit the proper positioning of the work to a setting which gives longest cutter life. Under such a condition, there seems to be no definite means available which will assist in determining the diameter of a face mill capable of producing the maximum number of pieces per grind. This problem of determining optimum cutter diameter for a given face-milling job, and the proper positioning of the workpiece in relation to the cutter, led to a series of studies, the results of which are reported in this paper.
Resistance of Nickel-Containing Alloys to Corrosives Encountered in the Petroleum Refineries
Authors: Morton B. B. 
Published: December 2022

Abstract
Production of bulk gasoline in a modern petroleum refinery is accompanied by corrosion during topping and cracking from sulphur and from weak hydrochloric acid which is formed from salts in the crude. Organic acids such as naphthenics are also often present and are quite corrosive. Solutions of refinery corrosion problems are considered in this paper.
Rotary-Pump Theory
Authors: Wilson W. E. 
Published: December 2022

Abstract
A theory describing the performance of rotary positive-displacement pumps and fluid motors in terms of torque and delivery is presented. From the equations for these two quantities, expressions for power input and power output are developed. The concept of torque efficiency as a complement to the concept of volumetric efficiency is introduced. Equations are developed for the volumetric, torque, and over-all efficiencies. Three operating ranges are identified by outstanding characteristics of the performance in each case. Performance charts in dimensionless form are presented and analyzed. Tests on a conventional gear pump operated as a fluid motor yield data which substantiate the theory in one operating range. Additional tests on a cam-type pump give data confirming the predictions of the theory concerning the performance when pumping oils of high viscosity. Alterations of the physical dimensions of the unit are discussed in terms of effect on the performance characteristics. The possibility of the design of units with optimum dimensions is indicated.
Special Studies of the Feedwater-Steam System of the 2000-Psi Boiler at Somerset Station of Montaup Electric Company
Authors: Bissell W. D. , Cross B. J. , White H. E. 
Published: December 2022

Abstract
In conjunction with other studies on the high-pressure forced-circulation boiler at the Somerset Station of the Montaup Electric Company during the past 3 years, tests to determine, particularly, the extent of dissolution of iron throughout the system, and the formation of high-iron sludges were made. A summary of the findings of this investigation are given in this paper.
Water Conditioning for the 2000-Psi Boiler at the Somerset Station of Montaup Electric Company
Authors: Cerna W. W. , Scott R. K. 
Published: December 2022

Abstract
Considerable interest has been aroused in the chemical treatment used for the high-pressure boiler at the Somerset Station of the Montaup Electric Company. The theoretical aspects of the present treatment, which has been in use since January 1, 1944, are given in a paper by Hall. Details of the results obtained with the different types of treatment used on this boiler have been given in a paper by Parks. It is largely the purpose of this paper to present the reasons for the various methods of chemical treatment which have been used, and for the changes made, which have resulted in stabilization of the boiler-water conditioning since January 1, 1944.
Experience With Instruments and Control Equipment for 2000-Psi Boiler at Somerset Station of Montaup Electric Company
Authors: Bissell W. D. , Powell E. B. 
Published: December 2022

Abstract
This paper presents comprehensive descriptions and operating experiences with the instruments and control equipment as applied to the high-pressure high-capacity boiler of the Somerset Station. Details are given not only of the completely automatic operating and control equipment but also of the indicating and recording instruments which enable the operators to follow constantly the operating conditions of the boiler and thus permit immediate manual adjustment when the need is indicated.
Conversion of Measurements of Power Output of Diesel Engines to Standard Atmospheric Conditions
Authors: Elliott Martin A. 
Published: December 2022

Abstract
This report presents and analyzes data obtained on the effect of ambient or atmospheric conditions on the power output of three normally aspirated commercial four-stroke-cycle Diesel engines. Different ambient conditions were simulated by maintaining the desired pressure in each of two surge tanks, one connected to the intake and one connected to the exhaust of the engine. The simulated absolute pressures ranged from 20 to 30 in. of mercury. Most of the tests were made at the prevailing atmospheric temperature but a series of tests with one engine was made at an intake temperature of approximately 230 F. Analysis of the results showed that an algebraic relation could be obtained between so-called “derived indicated efficiency” and fuel:air ratio. This relation is independent of ambient conditions and is used in the development of rational procedures for correcting measurements of power output made at existing test atmospheric conditions to any arbitrarily selected standard ambient condition. Using certain of the basic relations developed, an expression was derived for computing the brake horsepower of an engine at any ambient density and rate of fuel consumption. Computed values were within 0.7 hp of values determined experimentally. The report also reviews previous work in the field and indicates the need for further work to obtain the complete solution of the problem desired by the A.S.M.E. Special Research Committee on Internal-Combustion Engines.
Relation Between the Impact and Flexural Tests for Molded Plastics
Authors: Welch L. E. , Quackenbos H. M. 
Published: December 2022

Abstract
A theoretical treatment of the phenomena of impact is presented which indicates that rupture under dynamic stress-strain conditions results from the same basic considerations as those governing static or flexural failure. This thesis is proved experimentally by reducing the problem to one of stress rather than the usual method of energy evaluation. When this is done with the aid of newly developed high-speed electronic techniques, it is conclusively demonstrated that impact loading is merely a special case of static loading whereby the stress-strain conditions are identical except for a slight elevation in strength under dynamic conditions. It is shown that the existing methods of impact-strength evaluation such as the standard Izod and Charpy tests lead to erroneous results since the machines in use are apparently of too light a construction, and the technique is oversimplified. It is suggested that the static flexural-test technique when properly carried out to evaluate the energy required for fracture and the notch sensitivity, is sufficient to predict the service characteristics of essentially brittle materials under conditions of both static and impact loading.
Comparative Graphitization of Some Low-Carbon Steels With and Without Molybdenum and Chromium
Authors: Smith G. V. , Brambir S. H. , Benz W. G. 
Published: December 2022

Abstract
Study of several experimental heats of steel containing 0.5 per cent molybdenum and up to 1.20 per cent chromium showed that in steels containing 0.5 per cent or more of chromium, no graphitization occurred in 3000 hr at 1025 F; but this finding requires confirmation by study of additional heats, particularly of commercial manufacture. Additional studies relating to the effect of deoxidation practice, particularly in plain carbon steels, and of the effect of posttreatment of welds on graphitization are described.
Graphitization in Some Cast Steels
Authors: Smith A. J. , Urban J. B. , Bolton J. W. 
Published: December 2022

Abstract
Field service and controlled laboratory experiments have demonstrated that it is not possible to insure against graphitization of carbon-molybdenum steel through any of the controlled procedures of melting and deoxidation practice or heat-treatment. It is probable that freedom from graphitization is to be sought through the use of alloy additions which confer greater stability to the carbide. A hypothesis has been put forth concerning the mode of graphitization based upon the observed graphitization behavior of both plain-carbon and carbon-moly steels. Use has been made of this hypothesis to explain the resistance to graphitization of the nickel-chromemoly steels. The experimental evidence would appear to indicate that the hypothesis is substantially correct.
A Better Method of Representing and Studying Water-Turbine Performance
Authors: Sutherland R. A. 
Published: December 2022

Abstract
The author indicates that the contour form of turbine-efficiency diagram has advantages in giving a clearer picture of performance than the usual efficiency curves. An example illustrates that several different variables can be shown on such diagrams. Formulas are derived for finding the discharge diameters of runners and are illustrated by examples. A simple method of determining the mutual influence of turbine speed and water hammer during transient conditions is illustrated by an example. Finally, the operating stability of a water turbine supplying an independent load is brought forward for discussion.
Nantahala Turbine
Authors: Growdon J. P. , Terry R. V. , Gnuse H. H. 
Published: December 2022

Abstract
The Nantahala plant of the Nantahala Power and Light Company is located near Franklin, N. C., and was designed by the Aluminum Company of America. The 60,000-hp hydraulic turbine operates under 925 ft rated net head at 450 rpm. The static head on the plant of 1008 ft is the highest for any reaction-type turbine installed in the United States. The design and construction of this turbine and butterfly valve are described, followed by results of the field tests. Operation and maintenance work undertaken since the unit was installed are frankly discussed. The field tests showed an efficiency of 93.7 per cent. Considerable stainless steel was used in the original installation and its use has been greatly extended since the unit was placed in operation.
Mechanical Oscillators and Their Electrical Synchronization
Authors: Herwald S. W. , Gemmell R. W. , Lazan B. J. 
Published: December 2022

Abstract
Mechanical oscillators provide an excellent means for obtaining structural serviceability tests. The adjustable-while-running type is particularly flexible. With it the answers to certain fundamentally difficult problems can be obtained quickly. The electrical system presented provides accurate remote control of frequency and phase angle between forces of two or more mechanical oscillators. In addition, means are incorporated for changing and indicating remotely the amount of unbalance of each oscillator unit. Rototrol units used with electronic and magnetic controls are the basic elements of this precise servomechanism.