bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Buckling of Thin Elastic Plates
Authors: Zizicas G. A. 
Published: July 2022

Abstract
The behavior of thin elastic plates under loading parallel to their middle plane, constant or arbitrarily varying with time, is considered. The effect of vibrations in the middle plane is examined. In the transverse direction it is shown that by introducing appropriate nondimensional variables and parameters the time dependence reduces to the same type of equation as in the case of columns. Thus the fundamental features of plates and columns are similar. Additional discussion and examples of the solution of the nondimensional equation are presented. Higher modes are related to the fundamental mode of the same plate under appropriate different loading. The need of considering the entire time history of the loading is shown by examples. Shear loading and various boundary conditions are discussed. For loading constant during the time of application initially curved and eccentrically loaded plates are proved equivalent models for the investigation. A slight modification is necessary for a load arbitrarily varying with time.
The Process Characteristics Which Affect Automatic Control
Authors: McMahon J. B. , Ackley R. A. 
Published: July 2022

Abstract
The important process factors which affect the application of automatic control are discussed under three headings: (a) In the section for selection of criteria of process conditions, it is emphasized that the factors selected to represent process operating conditions must truly represent the conditions and bear a substantially linear relation to them. Discontinuities are to be avoided. (b) Self-regulation is a sustained reaction inherent in a process which assists or opposes the establishment of equilibrium. Its presence or absence may determine whether or not automatic control is practical. Typical examples are given. (c) Process lag is classified under six different types of common time reactions. A qualitative discussion points out which types of lag and lag combinations assist and which oppose good automatic-control results. The effect of automatic-control arrangement and regulator performance are brought out. Hydraulic examples of process-lag combinations are presented, with the corresponding reaction curves.
Radial-Flow Compressors and Turbines for the Simple Small Gas Turbine
Authors: Wosika L. R. 
Published: July 2022

Abstract
This paper describes the procedure followed in developing an acceptable radial-flow turbine for use with a lightweight gas-turbine-driven fire pump for the Navy Bureau of Ships. In the course of this work considerable data were accumulated on general design information and practice on radial compressors and turbines. A review is given of these data as well as the current design approach for a simple cycle radial-flow gas turbine. A discussion of the factors and variables which affect the performance of radial turbomachines is included.
Machining of Heated Metals
Authors: Armstrong E. T. , Cosler A. S. , Katz E. F. 
Published: July 2022

Abstract
Studies are reported of the machinability of several materials at elevated temperatures. It was found that tool life, cutting austenitic stainless steel, was increased tenfold by heating to 400 F. High-temperature alloys, including vitallium, machined freely at temperatures from 700 F to 2000 F. Long curling chips and a smooth cleanly cut surface were produced in hot-machining. The same materials cut at room temperature developed a glazed uneven surface, and the chips were powdery. Austenitic manganese steel machined easily at 1200 F, as did fully hardened high-speed steel. An arc heating method was developed which permitted continuous heating while machining, without heating the work throughout.
Metals for High-Pressure Hydrogenation Plants
Authors: Nelson G. A. 
Published: July 2022

Abstract
Many of the important chemicals of today’s industrial economy require processing in the presence of hydrogen, at elevated temperatures and pressures, at some stage in their manufacture. The more familiar ones are ammonia, methanol, edible oils, and higher alcohols. In the petroleum-refining field, hydrogenation processes are becoming more and more important. In the future it can be anticipated that greater need for hydrogenation processes may arise, for example, hydrodesulphurization of crude oils or fractions therefrom, hydrogenation of carbon monoxide (Fischer-Tropsch), and destructive hydrogenation of oil residues or coal (Bergius process). These processes operate at high temperatures and pressures, where ordinary steels have their limits for safe operation. Although high-alloy steels can be used under these conditions, oftentimes more reasonably priced low-alloy steels are satisfactory. This paper summarizes the results of tests and data from operating plants, from which it is possible to establish practical operating limits for carbon and alloy steels for all degrees of severity of service. Additional corrosive effects by sulphur, nitrogen, and carbon monoxide are discussed.
Report of Progress on Measurements of Friction Coefficients, Recovery Factors, and Heat-Transfer Coefficients for Supersonic Flow of Air in a Pipe
Authors: Kaye Joseph , Keenan J. H. , McAdams W. H. 
Published: July 2022

Abstract
Measured values are presented for friction coefficients, recovery factors, and heat-transfer coefficients for a stream of air flowing through a pipe at Mach numbers ranging from 2.5 to 1.2. The friction coefficients are in good agreement with those of Keenan and Neumann. At a diameter Reynolds number at inlet of about 1 × 105, which is intermediate between values observed by Keenan and Neumann, frictional effects of a very low order were observed. Maximum frictional effects occurred at a diameter Reynolds number at inlet of about 1.5 × 105. Friction coefficients are, in general, considerably lower than those for fully developed turbulent flow of incompressible fluids at the same values of the Reynolds number.
For laminar boundary layer, it appears that the recovery factor is in close agreement with the results of the Pohlhausen analysis, namely (Pr)1/2 or 0.865. For turbulent boundary layer the recovery factor appears to vary from about 0.79 where the Mach number is 1.3 to about 0.865 where the Mach number is 2.2. It cannot be determined from the present tests whether this variation is primarily an effect of variation in Mach number, although it probably is.
The measured values of heat-transfer coefficient in the region of laminar boundary layer seem to be roughly in accord with the Pohlhausen analytical values for incompressible flow over a flat plate. In the region of greatest turbulence in the boundary layer, agreement with the McAdams correlation of data for turbulent flow in pipes is good. The major portion of the data obtained appears to be in the region of transition in the boundary layer from laminar to turbulent flow. Most of the observed values of heat-transfer coefficient are smaller by far than the corresponding ones for fully developed turbulent flow—the ratio of one to the other being as small as 1 to 10.
Residual Grinding Stresses in Mild Steel
Authors: Frisch J. , Thomsen E. G. 
Published: July 2022

Abstract
A method for determining residual surface stresses is presented. For their determination, it is necessary to remove small layers from the part which has been bent by the residual stresses in the unrestrained state and to measure the resulting change in deflection and thickness of metal removed. Etching with a weak nitric acid and water solution was found to be a satisfactory method for removing surface metal without introducing additional stresses. Mild-steel bars were ground with a medium-soft grinding wheel in a surface grinder. The depth of surface layer containing residual stresses extended to approximately 0.012 in. to 0.018 in. below the surface for grinding cuts ranging in depth from 0.0003 in. to 0.003 in. The thickness of the layer containing residual stresses increases with increasing depth of grind. The maximum residual stress occurs on the surface and, for all depths of grinds, was considerably above the yield point of the original material. The maximum surface stresses when grinding mild steel within the foregoing range of depth of cut decreases with increasing depth. It is believed that this phenomenon can be explained by the possible partial recrystallization of the surface grains because of the higher surface temperatures obtained with heavy cuts.
Stress Distribution in the Continuous Chip—A Solution of the Paradox of Chip Curl
Authors: Henriksen E. K. 
Published: July 2022

Abstract
This paper is intended to throw light upon the hitherto unsolved problem of chip curl. The chip passes along the tool face for a certain distance before it leaves the tool and then curls through space. The author assumes that a sudden drop in pressure occurs at the point of ultimate contact, which combines with a single force at this point. The physical origin of this system of forces is explained by surface roughness of the tool, which leads to an explanation of the sharp boundary line for the area of wear on the tool face. Distribution of pressure between chip and tool follows an exponential law. Methods of stress analysis are explained which should be useful in further investigations.
Index Testing of Hydraulic Turbines
Authors: Voaden G. H. 
Published: July 2022

Abstract
The object of this paper is (a) to bring to the attention of operating companies the benefits derived from index tests of hydraulic turbines, and especially those of the adjustable-blade propeller or Kaplan type; (b) to enumerate and discuss the presently known methods of determining relative discharge and hence relative efficiency; (c) to present an example of an index test of an adjustable-blade propeller turbine in sufficient detail to provide a guide for the conduct of such a test.
A Method for the Calculation of Heat Transfer in Solids With Temperature-Dependent Properties
Authors: Plunkett Robert 
Published: July 2022

Abstract
The problem of heat transfer in a solid, whose conductivity and specific heat depend on the temperature, is converted by a simple change of variable to one in which the conductivity may be held constant, and only the specific-heat term varies with temperature in a way which depends upon the variation of both parameters. The method is illustrated by application to a problem previously solved by Dusinberre in a different way. The effect on the final solution of different finite approximations to the derivatives is also discussed.
Performance of Oil-Film Bearings With Abrasive-Containing Lubricant
Authors: Roach A. E. 
Published: July 2022

Abstract
This paper describes an experimental study of the embedability of bearing materials, i.e., the ability of bearing materials to operate on lubricants containing abrasive particles. It is found that the rate of temperature rise suffered by the bearing when abrasive-containing oil is introduced into it offers a convenient criterion for rating the embedability performance of various bearing materials. Data are presented on the effect of varying babbitt-overlay thickness and copper-lead composition of gridded surfaces and of oil grooves. Relative embedability ratings for seventeen different bearings are correlated with wear rates.
The Effect of Oil Viscosity on the Power-Transmitting Capacity of Spur Gears
Authors: Borsoff V. N. , Accinelli J. B. , Cattaneo A. G. 
Published: July 2022

Abstract
In tests made on spur gears with mineral oils of various viscosities, it was observed that a relationship exists between the maximum horsepower which the gears can transmit without scoring, and the product of gear speed and lubricant viscosity. An analysis of the factors entering into this relation indicates that these are the same that occur in Lewis’ equation used in gear design, except that the latter does not contain the lubricant viscosity. If this viscosity is introduced into the Lewis equation, the latter represents the experimental points for horsepower transmitted at the onset of scoring very well over a wide range of speeds and lubricant viscosity. This modified Lewis equation appears to apply to spur gears, in general, and indicates that the influence of lubricant viscosity on the power-transmitting capacity of gears is much too great to be neglected in the design of gears.
An Introduction to Arc-Cast Molybdenum and Its Alloys
Authors: Ham J. L. 
Published: July 2022

Abstract
The advantages and limitations of the arc-casting method for producing metallic molybdenum and its alloys are discussed. The general properties of unalloyed cast molybdenum are described and curves are presented to show the room temperature tensile properties, hardness, and notched-bar values after annealing at various temperatures, the effect of testing temperature on hardness, and the transition temperatures for various types of impact tests.
The need for addition of alloying elements is discussed. Preliminary selection of appropriate alloying elements was based on their vapor pressures and known or expected solid solubility limits. Curves are presented showing the solid solubility limits of silicon, aluminum, iron, cobalt, and nickel in molybdenum at various temperatures as determined by the measurement of lattice parameters of arc-cast samples, and the effects of beryllium, aluminum, silicon, titanium, vanadium, chromium, iron, cobalt, nickel, zirconium, columbium, tantalum, and tungsten on the hardness of molybdenum at various temperatures.
Molybdenum containing a small amount of beryllium can be hardened by quenching and softened by slow cooling.
Regardless of which alloying element is used, there appears to be a limit to the increase in hardness that can be tolerated without causing difficulty in hot-working by the techniques applied so far.
The effects of several of the alloying elements on the rate of work-hardening and on the temperatures of softening and recrystallization were studied using a series of alloys which were extruded.
Experience With Austenitic Steels in High-Temperature Service in Petroleum Industry
Authors: Holmberg M. E. 
Published: July 2022

Abstract
Experience in the petroleum industry shows there are other factors besides tensile, creep, and stress rupture to consider in the use of austenitic steels in high-temperature service. There is no advantage in using stabilized grades in many applications. A spheroidizing heat-treatment is generally effective where stabilized steel is required. The coefficient of expansion and the thermal conductivity have been important factors in thermal-shock and thermal-fatigue failures in austenitic steels.
An Investigation of the Role of Aluminum in the Graphitization of Plain Carbon Steel
Authors: Hall A. M. , Fletcher E. E. 
Published: July 2022

Abstract
This investigation was sponsored by Project No. 29 of the Joint ASTM-ASME Committee on the Effect of Temperature on Properties of Metals, and was directed toward casting more light on the role of aluminum in the breakdown of iron carbide in plain carbon steels into iron and graphite at temperatures below the lower critical point of the steel. The approach to the problem was to extract the carbides from several plain carbon steels which had been deoxidized with different amounts of aluminum and had different known degrees of susceptibility to graphitization, and then to examine and analyze the extracted carbides, with particular attention to the amount and form of the aluminum therein. By comparing the aluminum found in the carbide with the aluminum of the original steel, data were obtained on the role which that element appears to play on the graphitization process. The results strongly suggest that a graphitization-resistant plain carbon steel does not differ fundamentally from one which graphitizes readily. It is tentatively concluded that, in order to promote graphitization, the aluminum is either in solid solution in the ferrite matrix, or else fixes the nitrogen as AlN. Which of these forms it takes could not be determined from the results. The results further suggested that any aluminum which might be associated with the carbide phase is not influential in determining the degree of susceptibility to graphite formation.
A New Method of Determining Thermal Diffusivity of Solids at Various Temperatures
Authors: Rosenthal D. , Ambrosio A. 
Published: July 2022

Abstract
The method under review affords a rapid means of determining thermal diffusivity and is especially suitable to measurements at high temperatures. The theory of moving heat sources is the basis for this method. When the theory is applied to the case of unidimensional heat flow in a long prismatic bar, being heated by a moving point heat source, an equation which permits the computation of thermal diffusivity at each temperature is obtained. The experimental technique involves the measurement of the temperature-time history at a single point of the bar, using two different heat-source velocities. The method was tried on a commercial “yellow” brass tube, but the equation derived for the computations proved to be unworkable owing to the poor accuracy attending the evaluation of the first and second-order derivatives of the temperature-time curves. To avoid this shortcoming another equation was derived by assuming that the thermal properties of the bar are constant in small intervals of temperature. This equation gives average values of diffusivity in the small intervals of temperature, rather than a specific value for each temperature. This approximation notwithstanding, the intervals of temperature could be made small enough to determine the values of thermal diffusivity of the brass specimen in the range 100 to 400 C with a repeatability of ±3 per cent. These computed values compare favorably with those found in the literature.
Coal Sampling by Large-Increment Weights
Authors: Landry B. A. , Anderson W. W. 
Published: July 2022

Abstract
A sampling experiment is described that was aimed at determining the variance in percentage ash of large-weight, single-increment samples of an Indiana coal. The observed variance is broken down into its component parts which are calculated from the data obtained. Results show that for increments of large weight, such as are taken by mechanical samplers, at large steam-generating stations, relatively few would be required, for the coal studied, to obtain a gross sample meeting present accuracy standards. The suggestion is made that studies on other coals should be made to confirm these findings which, if generally true, may lead to an upward revision of standards of accuracy in view of the practicability of taking larger numbers of increments mechanically.
Corrosion-Erosion of Boiler Feed Pumps and Regulating Valves at Marysville, Second Test Program
Authors: Decker J. M. , Wagner H. A. , Marsh J. C. 
Published: July 2022

Abstract
Corrosion-erosion tests at 320 and 385 F indicated that, at these temperatures, carbon steel is attacked to a lesser extent than at 250 F, whereas the reverse is true of the chromium-bearing steels. However, the rate of attack of the chromium steels is still only a fraction of that of carbon steels, so that use of the alloy steels for boiler-feed-pump parts is warranted at the higher temperatures also. Increasing the pH of the feedwater from 7.6 to 8.4 doubled the corrosion-erosion attack on carbon steel in the Marysville boiler feedwater at 250 F, as compared with previous tests at the lower pH. Of two bronzes tested, Navy M material appeared satisfactory at temperatures up to 320 F; a leaded bronze was unsatisfactory at all test temperatures in this program.
Development of the Hydraulic Design for the Grand Coulee Pumps
Authors: Blom Carl 
Published: July 2022

Abstract
The Grand Coulee pumping plant has been the subject of an extensive hydraulic research program. The first part of this program was conducted at The California Institute of Technology for the Bureau of Reclamation from January, 1938, to July, 1940. Some of the results of this program have already been published (1 to 4), and other papers (5, 6) describe the different features of this project. This paper presents some of the results of continued experimental research of the author’s company from 1943 to 1946. The investigation covered the effects of various diffuser-type pump cases and impellers on the pump characteristics of the Grand Coulee model. The paper concludes with the description of the final test of the contractor’s model completed in July, 1947.
Effect of Fuel-Immersion on Laminated Plastics
Authors: Crouse W. A. , Carickhoff Margie , Fisher Margaret A. 
Published: July 2022

Abstract
The effects of cyclic and of continuous immersion in heptane, toluene, and SR-6, a test fuel, on the weight, dimensions, and flexural properties of nineteen samples of laminated plastics are reported. No one sample exhibited smaller changes than all other samples in all properties for all fuels, and for both cyclic and continuous immersion. The best weight and dimensional stability in the cyclic test was shown by a glass-fabric unsaturated-polyester laminate. The changes in flexural strength as well as in modulus of elasticity were losses in the majority of cases after the cyclic- and the continuous-immersion test. The unsaturated-polyester laminates varied widely among themselves in regard to the magnitude of the changes in a given property after an immersion test.
The Design of Sewaren Generating Station and No. 1 Unit at Essex Station, Public Service Electric and Gas Company
Authors: Fairchild F. P. 
Published: July 2022

Abstract
The author outlines the more important considerations leading to the design of the 100,000-kw unit at Essex and the four-unit Sewaren Generating Station. Outstanding features are semioutdoor boilers at latitude 41°; 1050 F steam temperature; a simplified plant layout, including the unit system; central control; shaft-end house generators; and all-electric auxiliary drive. The improvements in calculated plant heat rates are shown for the progressive steps of the program. Some of the more important electrical and architectural features are described.
Frictional Characteristics of O-Rings With a Typical Hydraulic Fluid
Authors: Cheyney L. E. , Mueller W. J. , Duval R. E. 
Published: July 2022

Abstract
O-ring packings employed in aircraft hydraulic systems are subject to numerous operating variables, which affect the friction involved in their operation. A method for studying the friction is described, and the effects of several variables—pressure, time delay, squeeze, stroke speed, ring size, and surface finish of the moving metal part—have been determined.
Investigation of Lubricants for Power Circuit Breakers
Authors: Bush R. R. 
Published: July 2022

Abstract
This paper describes a technique for the selection of proper lubricants for power circuit breakers. The circuit breaker is described briefly, and its lubrication requirements for dependable operation are discussed. The laboratory methods set up to determine the performance of the grease best suited for this application are outlined. Results of the laboratory test data are shown and evaluated with reference to circuit-breaker requirements. Properties of some typical greases are compared with their performance for this particular application. Because performance depends not only upon grease properties, but also upon the process of manufacture, the greases tested are referred to only in code. Life tests on actual circuit breakers have checked laboratory results. Therefore it is concluded that tests may be set up to determine the suitability of a lubricant for any particular application and especially for power circuit breakers.