bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design Problems of Controllable-Pitch Propellers
Authors: Heinz W. B. 
Published: April 2023

Abstract
This paper presents analytical studies of the most common problems that are encountered in the design of mechanisms to rotate airplane propeller blades about their axes. It includes (1) a brief discussion of centrifugal thrust-bearing loads, (2) an analysis of the torque created by centrifugal force, (3) an analysis of lateral bearing loads from which their frictional torques can be determined, and (4) an investigation of the centrifugal torque of multiple masses by means of which a counterbalance can be designed to neutralize to any desired extent, at all settings, the centrifugal blade torque. The analyses are carried further than in previous published work, and results are reached by which quantitative design data can be obtained with minimum numerical and graphical labor.
Analysis of Stresses in Circular Plates and Rings: With Application to Cylinders With Rigidly Attached Flat Heads and Flanges
Authors: Holmberg E. O. , Axelson Karl 
Published: April 2023

Abstract
While the fundamental theory for calculating stresses in circular plates is well known, it has not been employed generally by engineers because of its complexity. In the present paper the authors present a simplified method for calculating the stresses in flat, circular plates, with or without a hole in the center, the loads being applied in any manner provided they are uniformly distributed in circles concentric with the edges. They also discuss the stresses in a hollow cylinder having rigidly attached flat heads, and give a method of calculating stresses in cylinders with rigidly attached flanges.
The Use of Models in Determining the Strength of Thin-Walled Structures
Authors: Saunders Harold E. , Windenburg Dwight F. 
Published: April 2023

Abstract
This paper discusses the status of fundamental theories and explains the circumstances surrounding the use of models to determine the strength of three types of thin-walled structures. The particular types selected represent problems in naval architecture, but their counterparts are frequently encountered in other engineering structures.
Special emphasis is devoted to the necessity for obtaining geometrical similarity between the model and its original and for using identical materials if consistent and reliable data are to be obtained.
The actual methods used in the fabrication of representative models are described in considerable detail, as an aid in their application to other model research. The limits to which riveting and welding can be duplicated are defined, and the use of soldering and spot welding as alternatives is discussed.
In conclusion, the authors point out that the application of intensive thought and study to model research, commensurate with the care devoted to the design of the full-scale structure, is imperative if reliable results are to be expected from the work.
Resistance of Slender Bodies Moving With Supersonic Velocities, With Special Reference to Projectiles
Authors: von Kármán Theodor , Moore Norton B. 
Published: April 2023

Abstract
The hydrodynamical equations for the steady flow of a compressible fluid with axial symmetry are applied to the case of a slightly disturbed parallel flow with velocity higher than the velocity of sound. The linear equation obtained in this way is integrated by a numerical method, and the solution applied to an approximate calculation of the pressure distribution at the head of a projectile. The question of the drag of projectiles is discussed and the results of the theoretical calculations compared with the values obtained from ballistic experiments. The numerical calculations have been carried out by the junior author, using the methods suggested by the senior author.
Recent Developments in By-Products From Bituminous Coal
Authors: Fieldner A. C. 
Published: April 2023

Abstract
After pointing out that the by-product oven has displaced the beehive oven as a producer of metallurgical coke, the author discusses the increasing value of by-products as compared to that of the coke itself. He then takes up successively the subjects of competitive sources of gas for industrial and domestic use; utilization of the hydrogen in coke-oven gas for the production of synthetic ammonia; competition between synthetic and by-product ammonia; utilization of sulphur in coke-oven gas in the production of ammonium sulphate; processes for the recovery of sulphur in connection with gas purification; recovery of phenols from ammonia still wastes; benzol and light oils; production of resins from coal by-products; tar and tar products; and the hydrogenation of coal tar.
Heat Transfer From Condensing Steam to Flowing Water: Accomplished Through Single Metal Tubes Which Are Completely Surrounded by Air-Free Steam
Authors: Brown A. T. 
Published: April 2023

Abstract
The method developed in this paper correlates in part some of the known experimental data for heat transfer through single tubes at low rates of heat flow with the experiments made by Geo. A. Orrok in 1910. This method may be used at low rates of heat transfer such as occur in condensers to establish an ideal with which to compare the actual performance. Such a comparison indicates how close the performance of the actual condenser approaches the rate of heat transfer which can be secured with a single tube completely surrounded by air-free steam. The formula for the heat transfer through the film on the water side of the tube is taken from a paper presented by Edwin R. Cox at the 1927 Annual Meeting of The American Society of Mechanical Engineers, and this formula is a development of data prepared by Chester W. Rice. The method given in this paper should prove useful in calculating changes in the rate of heat transfer caused by altering the velocity of the water in the tubes in an actual condenser with the inlet water at the ordinary temperatures, say, above 50 deg. fahr.
Improvements in Missouri-Kansas Coals and Their Burning Equipment
Authors: McDonald E. L. 
Published: April 2023

Abstract
In the producing of Missouri-Kansas steam coals, there always have been certain undesirable qualities, the reduction of which would materially improve the quality of the coal; namely, high ash, high sulphur, low fusion temperature, excessive moisture, and inconsistent quality. While these undesirable qualities exist in most coals, the character of the local coals and the mining method (mostly strip pitting) make them more evident in these fields. The effort put forth in recent years to improve the quality and the results obtained are briefly covered in this paper. During the past 25 years improvements have been made to reduce various operating problems and to increase boiler-room efficiency. The major improvements made in this field and the actual results obtained are also covered.
Hydraulic Butterfly Valves
Authors: Mahon Ross L. 
Published: April 2023

Abstract
This paper describes some of the special features of design found in the modern butterfly valve and which have been adopted within recent years, during which this type of equipment has been developed to meet some of the unusual requirements existing in many modern hydroelectric projects. Means for making this type of valve more effective in limiting leakage are discussed in some detail and attention is given to general considerations affecting the design of disks and bodies. Some interesting types of operating mechanisms are outlined, and various kinds of protective and auxiliary equipment are described. Recent applications of butterfly valves for free-discharge service have broadened their useful field, and the suggestion is made that valves of this type might well find future use for other purposes than those existing in the hydraulic-power industry.
Leakage Loss and Axial Thrust in Centrifugal Pumps
Authors: Stepanoff Alexey J. 
Published: April 2023

Abstract
The paper reports on experiments performed by the author at the Hydraulic Laboratory of the University of California with the equipment furnished by the Byron Jackson Company, Berkeley, Calif. Factors governing leakage loss and means to reduce leakage loss were studied. With a special pump, leakage was measured under actual operating conditions, using wearing rings of various types, width, and clearances. Tests were performed at four speeds and different heads. The results are presented in the form of curves, the coefficient of discharge through the clearances being plotted as ordinates against pressures at the wearing ring as abscissas. To facilitate the calculation of the pressure at the wearing ring the pressure distribution in the pump case was studied and an approximate formula was developed. The axial thrust in single- and multi-stage pumps was measured with a specially designed thrust bearing which indicated the thrust directly in pounds under actual operating conditions. New sources of thrust were established—those caused by unequal pressures on the impeller shrouds from the inside due to various causes, the most important of which are an uneven radial velocity distribution and cavitation. In multi-stage pumps, with impellers mounted back to back, generally considered balanced on account of symmetry, it was discovered that there is considerable axial thrust produced by unequal pressures in adjacent stages acting upon the shaft shoulders and impeller hubs extending through the walls of the adjacent stages. Means to eliminate this thrust were found.
Variations in Maintenance Costs and Procedure
Authors: Stoody E. V. , Ross G. I. 
Published: April 2023

Abstract
The paper treats in a new way the important function of maintenance in industry. It is an analysis of the ratio of the maintenance forces in 20 industrial plants. The authors give reasons for the discrepancies shown by the analysis. The paper should be of assistance to managers wishing to conduct their maintenance activities economically. The charts indicate by the wide dispersion of ratios that there is a large field for improvement in the general treatment of the maintenance problem.
Coordination of Research, Sales, and Production
Authors: Wilder Richard F. 
Published: April 2023

Abstract
This paper seeks to demonstrate how the various research activities are coordinated one with another, and then as a unit with sales and production, so as to consider related factors in the instigation and carrying forward of research projects. Likewise it aims to bring out how definite mechanisms of coordination may be established whereby the greatest benefits may be derived from the research activities through the development and manufacture of products which are both commercially and technically sound.
Influence of Chemical Composition and Heat Treatment of Steel Forgings on Machinability With Shallow Lathe Cuts
Authors: Digges T. G. 
Published: April 2023

Abstract
The tests described in this report were made primarily as a study of lathe-tool performance with shallow cuts as affected by variations in chemical composition and heat treatment of the steels cut. The cutting tests were made dry with high-speed-steel tools of a selected size, form, composition, and heat treatment, with a feed of 0.0115 in. per rev. and 0.010 in. depth of cut. Comparisons were made of the Taylor speeds on the basis of equal tensile strengths when cutting 0.4 per cent carbon (S.A.E. 1040), chromium-vanadium (S.A.E. 6140), nickel-chromium (S.A.E. 3140 and 3435), chromium-molybdenum (S.A.E. 4140), and 3½ per cent nickel (S.A.E. 2340) steel forgings heat treated to give tensile strengths between 75,000 and 220,000 lb. per sq. in.
The study also included consideration of the surface finishes of the various steel forgings as affected by the test conditions, the microstructures of the steels cut, and tool performance as affected by the additions of 3.5 to 11.7 per cent cobalt to the customary 18 per cent tungsten type of high-speed tool steel.
If machinability is measured by the cutting speed permitting the tools to last a definite time, then measurable differences were observed between the various steels cut in the lathe test with shallow cuts. The fact, however, that some given steel permits a higher cutting speed than another steel for some tensile strength which is the same for both materials does not necessarily indicate that the two steels maintain the same relationship for another tensile strength.
Of the different steels cut in the lathe tests, the plain carbon steel was the most difficult to machine other than an annealed nickel-chromium steel.
The surface finish on the plain carbon steel was also considered to be inferior to the surface finish of the alloy steels.
The results showed that the effect of changes in chemical composition of steel forgings upon their cutting speeds was dependent upon the tensile strength at which the comparisons were made. In the different steels cut with shallow cuts the most effective special alloying elements for improving machinability were the combinations of nickel and chromium or chromium and vanadium for the high tensile strengths in the neighborhood of 180,000 lb. per sq. in., while chromium and molybdenum were the most effective in the lower range of about 90,000 lb. per sq. in.
Fuel-Spray Formation
Authors: Lee Dana W. 
Published: April 2023

Abstract
Experiments are described in which the diameters of the fuel drops in sprays from different types of nozzles were measured and the effects of fuel-injection pressure, nozzle dimensions, and the density of the chamber air on the atomization of the sprays were determined. A simple method of determining the size and form of the high-velocity parts of sprays is also described. High-speed spark photographs of fuel sprays are shown that were made with lens systems having magnifying powers of 0.5, 2.5, and 10. These photographs reveal the process by which the fuel is transformed from the solid jet to the atomized spray, and also show the effect of several factors on spray dispersion.
New Development of Chromium-Tungsten Steel for Oil-Refining Service
Authors: Malcolm V. T. 
Published: April 2023

Abstract
Apparatus used in oil-refining service has been designed mostly from practical experience instead of experimental research, and the experience gained from operation over long periods gives notable results, among them being that certain alloys are resistant to corrosive conditions, and that if these alloys are used the so-called limiting creep stresses can be more than doubled over carbon steel. Other factors besides the strength of metals and corrosion resistance that must be considered are thermal expansion, thermal conductivity, resistance to abrasion, scaling, and oxidation. The search for an alloy steel that would resist the severe service in oil refining resulted in the development of chromium-tungsten steel. A series of tests are described in the development of properties required of a steel for high-temperature construction and service.
Suggested Specifications for Testing Tubular Heat-Transfer Equipment for Oil Refineries
Authors: Samans Walter 
Published: April 2023

Abstract
This is a draft of specifications for testing tubular heat-transfer equipment after it has been installed in the refinery, this draft to serve as the basis for a more complete and general specification to apply to any equipment of this character which may be used by the refiner in oil processing. Points are enumerated that must be considered by the designer, and some mechanical details are listed which the purchaser’s inspection must assure as being right, to avoid difficulties due to leakage of equipment, cleaning, and replacements in service.
Effect of Vacuum on Lubricating-Oil Distillation
Authors: Danforth R. S. 
Published: April 2023

Abstract
Vacuum distillation of lubricating oils possesses many advantages, and the paper brings out some of its basic features. The benefits of the vacuum process are mainly in the reduction of cracking, in the improved separation of fractions, and the reduction of heat input and condensing requirements. The author mentions a possible fractionator design and suggests a condenser design.
Flow of Steam Through Square-Edged Orifices in a 4-In. Line
Authors: Frymoyer W. W. , Herschel A. 
Published: April 2023

Abstract
The flow of steam through square-edged orifices has little in the way of available data. Tests were therefore run to secure the necessary data on steam-flow measurement. The objects were to determine coefficients for steam flow through square-edged orifices under conditions favorable to securing basic coefficients; to determine effects of various types of disturbances, both upstream and downstream, on basic coefficients; to determine effects of straightening vanes with 0.5 pipe diameter from the upstream edge of the orifice plate on coefficients. The general statement of the results may be made that, for the disturbances covered in the report, and with the orifices installed with vanes ½D from the upstream edge of the orifice plate, the actual coefficients will be near to 1 per cent of the 0.99 standard coefficient, for d/D ratios not over 0.75.
Development of Wood Adhesives and Gluing Technique
Authors: Truax T. R. 
Published: April 2023

Abstract
Study of adhesives used in furniture and other relics of earlier civilizations yields little of value to present-day craftsmanship. This paper therefore discusses only the more recent developments in glues and the technique of using them. While some glues were of ancient origin, the modern large-scale production and the more precise controlled methods have resulted in glues of higher and more uniform quality than the ancient glues from the same sources. Standardization of tests and testing methods is important. Joint tests constitute the principal means for determining the suitability of glues for woodworking. Tests that can be made directly upon the glues rather than upon glued joints may be developed.
Casein Glue
Authors: Leicester W. F. 
Published: April 2023

Abstract
Casein glue, made from soured skim milk, then dried, ground, and blended, has been in use in Germany for 50 years and in the United States for 30 years, but it was not until the World War period that it came into general commercial use. It was then that easy-to-use formulas of standard type were developed for the production of waterproof plywood in airplane construction. It now has general use in the woodworking industry. Casein glue in the past has relied upon harsh alkalis as a waterproofing agent. The casein glue of the future for veneering will be relatively only slightly alkaline, but will be high in water resistance through the addition to the dissolved glue of a chemical solution. The smaller user will have a glue that will carry overnight without loss of strength, will be quick setting and strong, and that will have sufficient water resistance for ordinary needs.
Some Observations on Raised Grain
Authors: Koehler Arthur 
Published: April 2023

Abstract
Woodworkers and finishers are confronted with certain difficulties classed under the category of “raised grain” which, so far, have resisted satisfactory solution. This paper describes some observations on raised grain that may lead to a better understanding of the problems and which may suggest approaches toward overcoming them. Casual investigations made of raised grain suggest some remedial measures, and indicate that there is a large field for research connected with the surfacing of lumber, both as to the cause of the objectionable features encountered and methods of overcoming them. A microscopical study of the way that present-day woodworking tools and machinery cut wood and the development of new equipment which would give more nearly ideal results seem to offer possibilities which would go a long way in improving wood products or reducing their costs.
Lightning Investigation as Applied to the Airplane
Authors: Austin A. O. 
Published: April 2023

Abstract
The hazard to aircraft from lightning is very small, but has received much attention. Lightning itself has caused but few fatalities, and many cases of trouble have been unjustly charged to it. Once the effect of lightning upon the pilot or plane is recognized, steps can be taken to materially reduce the hazard, if not to eliminate it. Some interesting information has been gathered from tests as to protection for free balloons and planes and other equipment.
Artificial Pay Load for Coming Commercial Airships
Authors: Blakemore T. L. 
Published: April 2023

Abstract
The most prominent field for the lighter-than-air vessel is across long stretches of water. The “Graf Zeppelin” confirms this by selecting as its first commercial venture the route between Germany and Brazil. There is a question whether the seagoing airship will merely be a high-speed, extra-fare auxiliary to the steamship or whether by radical improvement over present limited pay-load capacity it can be developed as a direct competitor to passenger-carrying ocean vessels at somewhat near to existing rates. The author suggests a number of means for artificially increasing pay load.
Possibilities of Cabin-Type Autogiros
Authors: Larsen A. E. 
Published: April 2023

Abstract
The development of the Autogiro has virtually been made on the open-cockpit type, one to three place, weighing from 1000 to 3000 lb, and with an engine of 80 to 400 hp. The question has often arisen if it could be adapted to passenger transport. The author asserts that the cabin-type Autogiro is entirely possible. Three cabin Autogiros have been built, markedly different as to type, size, power, and general construction. The trial flights in this country suffered because of lack of mechanical starting units, not then available. Detail studies have been made of various sizes of cabin-type Autogiros, and the author gives an idea of the possibilities in this development.
Steam and Power in the Bleached-Sulphite-Pulp Mill
Authors: Gibson W. R. 
Published: April 2023

Abstract
Methods of effecting economies in the use of steam in the paper industry are given, together with possibilities of water saving. After a brief description of the processes in a sulphite mill, a table is given of the probable requirements in steam and power for a 150-ton mill. The possibilities of combining the operations of a pulp mill and a sawmill are stated, the sawmill having a surplus of waste wood for fuel and of low-grade wood for pulping and usually exhausting large quantities of steam to atmosphere. The effect on refractories of hog-fuel ash is related.
Recent Developments in Merchant-Bar Mills
Authors: Fisk G. L. 
Published: April 2023

Abstract
After first discussing trade demands on merchant-mill products, the author points out the value of research and records in the making and rolling of steel. He then proceeds to discuss the factors affecting the quality of product in the merchant mill, and the items to be considered when selecting the type of merchant mill for a given range of products in a given plant. He next takes up the use and arrangement of vertical mills and the application of roller bearings to mill rolls, in case of existing and new mills, discussing also the economic and practical considerations involved. He then gives particulars of a new transfer-table design, and points out the uses and advantages of electric-driven flying shears. Finally, cooling-bed requirements to meet the needs of various merchant-mill products are then considered, as well as cooling-bed design and operation, objections to the double cooling bed, and double cold shearing from a single bed.
Management Policies and Practice in a Continuous-Production Gray-Iron Foundry
Authors: Reichert W. G. 
Published: April 2023

Abstract
In a continuous-production gray-iron foundry with a capacity of 250 tons daily, chiefly making small castings, the management policies and practice have been directed toward obtaining maximum results by the continuous molding-pouring method with the minimum expenditure of time and effort. The operation of this continuous foundry is described in detail, through all the processes from handling the raw materials to the final inspection of the product.