bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economic Thickness of Thermal Insulation for Intermittent Operation
Authors: Bradley C. B. , Ernst C. E. , Paschkis V. 
Published: December 2022

Abstract
Economic thickness of an insulation is defined as that thickness yielding the smallest sum of cost of heat loss and fixed cost of insulation. The difficulties in determining the economic thickness for intermittent operation are reviewed. By means of the electrical-analogy method, curves have been developed which permit the ready determination of the heat losses in intermittent operation for any temperature, any single-material wall, any intermittency, any length of period, and any film conductance. These curves permit the determination of the economic thickness for intermittent operation. The application of the curves is illustrated by an example. The influence of intermittency on the economic thickness is discussed for one specific case. The limitations of the method and prospect of obtaining results avoiding the limitations are considered.
Effect of Aeration on Gear-Pump Delivery and Lubrication Ceiling
Authors: Schweitzer P. H. 
Published: December 2022

Abstract
Gear-pump delivery falls off with altitude and, above a certain point, it fails to provide the necessary engine lubrication. By deductive reasoning, an equation has been developed for calculating the gear-pump delivery with aerated oil and also the “lubrication ceiling.” Charts are presented to show the effect on lubrication ceiling of (1) entrained air, (2) dissolved air, (3) pipe length, (4) pipe diameter, (5) tank height, pressure boost, valves, and ells, (6) oil viscosity, (7) pump speed. According to results obtained, a reduction of dissolved air and reduced pipe resistance between oil tank and pressure pump have relatively small effects on the lubrication ceiling. Effective ways to raise the ceiling are pressurizing the oil tank and reducing the pump speed.
Carry-Over in Locomotive Boilers
Authors: Williams Arthur 
Published: December 2022

Abstract
While tremendous advances in feedwater treatment to protect boiler heating surfaces from scale, corrosion, and embrittlement have been made, the methods commonly used on railroads have been accompanied by an increasing degree of foaming troubles. According to statements of the American Railway Engineering Association, the introduction of alkaline sodium compounds, while reducing the scale problem, has increased the foam-producing capacity of the water supplies. This paper approaches a solution to the problem of carry-over by discussing the mechanisms which cause other than dry steam to leave the boiler. The most important type of carry-over is probably that due to foaming. Carry-over by effervescence is also discussed. The effects of carry-over and methods of prevention are treated in detail. In the study of the problem and its correction numerous tests have been conducted by the author’s company, and by the A.R.E.A., and individual railroads. These are reported at some length, the results showing that proper control of feedwater treatment will help minimize foaming. Antifoam compounds increase the concentrations that may be carried in the boiler, but concentration must be controlled either manually or by automatic blowing. Apparatus of various types for this purpose is described, as well as a suitable design of steam separator, which is essential to separate the carry-over from the steam, and discharge the carry-over to the atmosphere.
On Fatigue Failure Under Triaxial Static and Fluctuating Stresses and a Statistical Explanation of Size Effect
Authors: Fowler F. H. 
Published: December 2022

Abstract
The purpose of this paper is to develop a framework for establishing a criterion of safe fatigue characteristics of manufactured units. In addition a statistical theory of fatigue has been indicated. Provision can be made for a study of combined stresses, static and vibratory stresses, and variations in amplitude. Interesting explanations of scale effect and stress gradient effect are given. It is hoped that this will provide a useful framework to improve the designer’s judgment and upon which to build additional work on fatigue.
Effect of Some Environmental Conditions on the Permanence of Cellulose-Acetate and Cellulose-Nitrate Sheet Plastics
Authors: Lawton T. S. , Nason H. K. 
Published: December 2022

Abstract
The effect of outdoor exposure, both in Florida and in Massachusetts, on the tensile properties, impact strength, optical properties, and shrinkage of cellulose-acetate and cellulose-nitrate sheet plastics is shown in detail, and the general nature of these effects is summarized. The effect of outdoor exposure on the composition of these plastics and on the molecular weight of the base cellulose esters is shown quantitatively. Moisture pickup and dimensional change upon immersion in water are reported.
Application of Controlled Atmospheres to the Processing of Metals
Authors: Peck C. E. 
Published: December 2022

Abstract
The development and application of separately controlled atmospheres for use in conjunction with heat-treating processes has been rapid during recent years. By means of controlled atmospheres, finished machine parts which require heat-treatment can be processed without loss of surface hardness during heating, and without further grinding or cleaning. Many other applications in the treatment of metals, such as welding, forging, melting, sintering, and the like, are possible although at present somewhat limited. This paper outlines the principal types of atmospheres and describes briefly the equipment available for producing these atmospheres. A summary is given of the application of these atmospheres to a wide variety of heat-treating processes now in active commercial use.
A Graphical Solution of Windshield Heat Deicing Problems
Authors: Hauger H. H. 
Published: December 2022

Abstract
It is the purpose of this paper to present the problem behind the design of an air-heated double-paneled windshield for aircraft. A windshield ice-prevention nomograph is proposed as a rapid accurate method of making a design analysis of the air-heated windshield. With its use the designer has at his disposal a visual means of determining the relative importance of the variables included within the design, so as to arrive at the optimum solution for a given installation under the conditions imposed. The sample problems analyzed in this paper indicate that the required windshield strength be designed into the inner panel with an outer panel of tempered glass so as to obtain the highest outer-surface temperatures.
Critical Shearing Stress in Skin-Stressed Boxcar Sides
Authors: Green V. L. , Drinka J. J. 
Published: December 2022

Abstract
Developments in boxcar construction are traced through the period of the 1920’s and early 1930’s, leading to design work by K. F. Nystrom on The Milwaukee Road in which 15-gage side sheets, stiffened by six longitudinals of the lapped type formed integrally with the side sheet, were found to be entirely satisfactory for car-side construction, and accomplished a saving in weight of 600 lb. In order to determine the possibility of further weight reduction without sacrificing strength, a study was made of the elastic stability of various types of car sides, and tests were conducted to correlate the theoretical study with actual test results. This paper includes a discussion of shearing stress in thin-webbed girders, the test procedure, a theoretical analysis of a number of panels tested, and the results obtained for the panels tested.
A General Correlation of Friction Factors for Various Types of Surfaces in Crossflow
Authors: Gunter A. Y. , Shaw W. A. 
Published: December 2022

Abstract
This paper is the elaboration of an unpublished one by the late E. S. Davis and A. Y. Gunter, which was released only to the National Advisory Committee for Aeronautics. The present work, using the friction-factor correlation proposed for bare tubes by Davis and Gunter, demonstrates its merit as a general method for correlating on a single line, pure crossflow friction over both bare and extended surfaces. This result is made possible through the use of an equivalent volumetric hydraulic diameter Dv, in both the Reynolds number and the ordinate, plus configuration ratios of the form (Dv/ST)n and (SL/ST)n in the ordinate. Friction factors for bare tubes of diameters from 0.02 in. to 2 in. are included, with transverse and longitudinal pitches ranging from 1.25 to 5 diam. Extended-surface crossflow friction reported on herein covers external round and square cross fins, both meshed and unmeshed, finned cylinders, radiator core-type surface, and one sample of internal wire-mesh fins. It is shown that flat plates and core-type surface with turbulence promoters do not correlate well on the proposed curve.
Heat Transfer Through Tubes With Integral Spiral Fins
Authors: Katz D. L. , Beatty K. O. , Foust A. S. 
Published: December 2022

Abstract
Heat-transfer data are presented for a group of tubes having integral spiral fins. The group includes tubes with a range of from 4 to 24 fins per in. and from 0.05 to 0.38 in. fin height. Seven series of measurements were made, using steam, air, water, and oil as fluids. The data are compared, when possible, with theoretical equations which apply to the particular heat transfer. The performance of tubes with the extended surface is compared in all cases with that of plain tubes tested under similar conditions.
Numerical Methods for Transient Heat Flow
Authors: Dusinberre G. M. 
Published: December 2022

Abstract
This paper deals with the application of numerical methods for the solution of heat-conduction problems, their generality being extended in the following ways: (a) A modulus is developed by choice of which the worker may proceed most rapidly to a solution, or may proceed more slowly and with greater precision; (b) criteria are developed for the choice of modulus to insure convergence. This is most important at a convective surface; (c) a method is developed for handling k and c when these properties vary independently with temperature. A comprehensive Appendix gives the derivations, and the use of equations and charts is demonstrated by typical examples.
Rate of Temperature Change in Short-Length Round Timbers
Authors: MacLean J. D. 
Published: December 2022

Abstract
This paper discusses factors affecting the rate of temperature change in wood and includes time-temperature curves for use in determining the temperature obtained at different points in short-length log sections when heated in steam or hot water. One group of curves shows the temperature distribution from the ends to the mid-length and at different points between the circumference and axis, of logs 12, 24, 36, 48, and 60 in. in diameter. Other charts show the time-temperature distribution at various points between the circumference and axis at the mid-length of log sections of any diameter between 12 and 60 in. Examples are given illustrating the procedure for using the charts in finding the temperature at a parcular point, under different heating conditions.
Measurements of Temperatures in Metal Cutting
Authors: Schmidt A. O. , Boston O. W. , Gilbert W. W. 
Published: December 2022

Abstract
Measurements of the heat developed in a metal-cutting operation, as well as investigation of cutting and chip temperatures by the authors have brought out that the chip temperature is uniform at the higher cutting speeds when all other conditions are kept constant. The temperature of the tool increases with the cutting speed, and the amount of metal removed before tool failure will generally be inversely proportional to the cutting speed.
The Influence of Tube Shape on Heat-Transfer Coefficients in Air to Air Heat Exchangers
Authors: Green F. H. , King L. S. 
Published: December 2022

Abstract
Heat-transfer coefficients are reported for air passing through round tubes, through partially flattened tubes, and through partially flattened tubes which have also been dimpled. It was found that flattened tubes maintained fully turbulent flow and, consequently, a higher heat-transfer coefficient at lower Reynolds number values than did round tubes. The addition of dimples to the flattened tubes maintained fully turbulent flow from the transition point and increased the heat-transfer coefficient substantially. The addition of the dimples also improved the relation between heat transfer and pressure drop in the flattened tubes.
The Control of Fouling Organisms in Fresh- and Salt-Water Circuits
Authors: Dobson John G. 
Published: December 2022

Abstract
The difficulties encountered by industrial water users due to fouling organisms are discussed. To control such fouling, a knowledge of the organism’s life cycle and reactions to stimulus is necessary. Typical mollusks, Bryozoa, sponges, barnacles, and tunicates are considered. Their control can be effected by heat, change of salinity, change of oxygen content, increased velocity, acids, antifouling paints, screening and poisoning with a number of different poisons. It is concluded that chlorination is the most effective and economical of these methods justifying itself in most plants by improved heat transfer alone. Factors to be considered in designing water systems that may foul are also outlined.
Design Considerations for Welded Machinery Parts
Authors: Snyder G. L. 
Published: December 2022

Abstract
Only some basic considerations for the designer in developing weldments are brought out in this paper, because of the wide scope of the subject. Separately, these basic considerations may seem elementary and self-evident, but when considered collectively in developing a weldment, their complexity becomes apparent. At least twelve different types of components can be utilized by a designer in his weldment and each of these components can be used in several ways. So, the designer must be familiar with limitations in processing weldments and with the scope and limitation of equipment and methods used in their production. These are the factors discussed here. However, this discussion is limited to dynamically loaded welded machinery parts.
Tests of Oil-Film Journal Bearings for Railroad Cars
Authors: Needs S. J. 
Published: December 2022

Abstract
This paper presents results of a special series of tests made with fitted and broached railway-car journal bearings as part of the program of the Journal Bearing Development Committee of the Association of American Railroads. Three recently developed bearings, each containing less bronze than the old standard A.A.R. bearing, were tested. Comparative tests were run with bath, pad, and waste-pack lubrication. Quantitative effects of fitted and broached bearing surfaces and method of lubrication on operating temperature, frictional power loss, and the all-important minimum film thickness are given. An attempt has been made to separate the friction of the bearing from that of the pad or waste-pack lubricator. Total frictional power losses of the box are given in terms of drawbar pull.
Air-Gas Ratio Control Applied to Nonatmospheric-Pressure Furnaces
Authors: McRae H. C. 
Published: December 2022

Abstract
For reasons of economy and efficiency, in the burning of fuel gases in industrial furnaces it is essential to maintain the air-gas ratio at approximately the correct point for perfect combustion. Furthermore it is important to control the ratio of air flow to gas flow because of the effect of burned gases or atmosphere upon material being heat-treated. The author discusses in detail the various control processes available, the equipment developed for the purpose, and analyzes the several control circuits, basing the work on the laws of low-pressure gas flow or noncompressible flow.
A Comparison of Operation of Forced- and Natural-Circulation Boilers
Authors: Ross G. F. , Wilkins Leonard 
Published: December 2022

Abstract
Steam-generating facilities at the Koppers Company, Incorporated, Butadiene Division, Butadiene-Styrene Chemical Plant, at Kobuta, Pa., include two types of units; natural-circulation boilers and the first forced-circulation boiler to be installed in the United States for industrial-plant processes. Since plant operation began in the summer of 1943, this installation has afforded boiler operators an opportunity to compare the operating characteristics of the two types. This paper describes briefly the design and operating features of these steam generators, together with some of the difficulties encountered and how they were overcome.
Water Injection in a Spark-Ignition Engine
Authors: Green W. P. , Shreeve C. A. 
Published: December 2022

Abstract
The present war witnessed a revival of interest in the use of water as a coolant and detonation suppressor inside the engine cylinder. Aircraft engines when operated with water injection have been boosted in output above normal sea-level capacity and have functioned satisfactorily. This paper gives a review of past tests on the use of water as a coolant and detonation suppressor in gasoline engines. It presents new data regarding the use of water in very high compression ratio engines to promote increased part-load efficiencies with low octane fuels.
Data From Activity-Recording Instruments Applied to Textile Machinery
Authors: Parsons C. S. 
Published: December 2022

Abstract
The author advocates the adoption of activity recorders in the analysis of production machinery operations widely throughout the textile industry, as a means of achievingim-proved performance and lowered costs. After describing the several types of equipment and their applications to the study of textile-machine operations, the paper explains the procedure followed in analyzing the data recorded.
Modern Methods in the Heat-Treatment of Steel
Authors: Mertz E. R. 
Published: December 2022

Abstract
The construction of time-temperature-transformation curves (S-curves) and their use in developing the interrupted-quench processes for steels are treated in this paper. Of these processes, martempering, austempering, and cyclic annealing are explained in detail. Martempering results in greatly reduced stresses in quenched parts, as compared to the conventional quench and temper method of hardening steel, and hence much less cracking and distortion is apparent. Austempering, an isothermal process producing bainite, develops surprisingly high impact properties in the region of 250,000 psi or 50 Rockwell C. Cyclic annealing is an elevated-temperature isothermal annealing process to produce a predetermined degree of softness, and saves much valuable time in the annealing of the higher alloy steels. The use of hardenability curves in establishing size limitations for particular heats of steel and in selecting accurate tempering temperatures is demonstrated.
Elevated-Temperature Stretch-Flanging of Some Aluminum Alloys
Authors: Thomsen E. G. , Cunningham D. M. , Dorn J. E. 
Published: December 2022

Abstract
Many aircraft parts consisting of a flat web and a concave flange are produced by rubber-die-forming on a hydropress. The forming action consists of bending the flange around the die radius and stretching the outer fiber of the flange from its original length to that which is achieved when it contacts the die. Several types of failures and defects are encountered, the most important being a radially directed fracture initiated at the outer fiber of the flange. When this fracture occurs without necking, the maximum per cent stretch that may be produced approximates the per cent local ductility in the tension test. If, however, fracture is preceded by necking, the permissible per cent stretch is intermediate between the uniform and local per cent strain in tension. Increasing the forming temperature permits greater per cent stretches for some of the more-ductile alloys.
Stress Analysis of Tube-Sinking
Authors: Sachs George , Baldwin W. M. 
Published: December 2022

Abstract
A theoretical stress analysis was made of the tube-sinking operation, equations being set up to yield the sinking stress as a function of the reduction in mean diameter. The equations were confirmed by experimentation on annealed and full hard copper and on annealed tube brass for conical dies of various tapers. The coefficients of friction existing during tube-sinking have been determined and are found to be of the same magnitude as those determined previously for wire drawing.
An Analysis of Intercooled Supercharging
Authors: Miller Ralph H. 
Published: December 2022

Abstract
In this and in an earlier paper, the author analyzes the internal-combustion engine as a heat engine. He finds that with present-day materials, the output of the internal-combustion engine is limited by the temperatures reached in the internal surfaces and not by lack of air to sustain combustion. A method is developed by which the output capacity of four-cycle engines may be increased by more than 100 per cent without exceeding practical and previously established temperatures of internal surfaces.
The Influence of Viscosity on Centrifugal-Pump Performance
Authors: Ippen Arthur T. 
Published: December 2022

Abstract
The wide use of centrifugal pumps in the oil industry demands that their performance characteristics for oil be predicted with reasonable assurance. A systematic study of performance changes with increasing viscosities had not been undertaken so far under controlled laboratory conditions. For the purpose of undertaking such a study theoretically and experimentally, the Hydraulic Laboratory of Lehigh University and the Cameron Pump Division of the Ingersoll-Rand Company co-operated in following through a comprehensive program of research at Lehigh University during 1944 and 1945. Over 200 performance tests for viscosities up to 10,000 SSU were completed on four variants of centrifugal pumps, employing a special test stand designed and built under war conditions.
The influence of viscosity changes on the head, discharge, and input-power characteristics of the pumps is demonstrated graphically and systematically for a wide range of viscosities and speeds. The usefulness of a special Reynolds number for pumps is demonstrated and test results are correlated on that basis. General conclusions are possible as to the influence of various features of design, since several pumps of different specific speeds were tested. A theoretical analysis establishes definitely the variables to be considered and places the discussion for the problem on a sound scientific basis, especially with regard to disk and ring losses.
Boiler Design for Extreme Load Variations
Authors: Kuhner M. H. 
Published: December 2022

Abstract
A summation of required design provisions for boilers adapted to operate under quick demand changes. Reference is made to the quick-pickup boiler in the Harbor Steam Plant of the City of Los Angeles and the steel-mill boiler at the Homestead Works of the Carnegie-Illinois Steel Corporation. The importance of water storage, unrestricted path for water and steam in circulation, steam release with minimum disturbance of water body in drum, steam-temperature control during unbalanced firing, and the effect of each item on the others, is discussed. Recommendations are made for determining required capacity of fuel-burning equipment and fans in reference to the extent and rapidity of steam-load changes.