bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Performance of an Extended-Surface Regenerator for a Gas-Turbine Plant
Authors: Holm Sven , Lyerly R. L.
Published: July 2022

This paper describes a new type of extended-surface heat exchanger developed for application to a gas-turbine plant for a natural-gas pipe-line pumping station. This regenerator features compactness and low weight, although the particular unit described is not as compact and light as could be made since primary consideration was given to material strength and service life, thus involving the use of relatively heavy sections for both primary and extended surfaces. Smaller-scale component parts would give higher heat-transfer coefficients and increase heating surface per unit volume by as much as 3 to 1.
The New-Type Code Chart for the Design of Vessels Under External Pressure
Authors: Bergman E. O.
Published: July 2022

This paper presents a new Code chart for shells and heads of pressure vessels under external pressure. The chart is especially adaptable to materials like nonferrous metals that have a nonlinear stress-strain curve. The curves for shells consist of two families with a common abscissa scale and different ordinate scales. One family represents the dimensional variables and is the same for all materials. The other family represents the mechanical property variables of a given material at different temperatures. Each curve is constructed from a stress-strain diagram of the material at the temperature it represents. A “head-line” curve provides for the design of hemispherical heads.
A Procedure for Determining the Allowable Out-of-Roundness for Vessels Under External Pressure
Authors: Holt Marshall
Published: July 2022

The procedure developed in the paper is based on the theory of thin shells developed by Dr. R. G. Sturm. The formula for determining the allowable out-of-roundness contains two factors, one based on the proportions of the shell and the other based on the properties of the material as measured by the allowable design stress. The procedure is applicable to elevated as well as to room temperatures.
Investigation of Turbulent Flow and Heat Transfer in Smooth Tubes, Including the Effects of Variable Fluid Properties
Authors: Deissler R. G.
Published: July 2022

Equations are derived for the prediction of radial velocity distributions for fully developed turbulent flow in smooth tubes both with and without heat transfer. The analysis results in an equation which represents both the conventional buffer layer and the laminar layer. In order to check the analysis and determine values for the constants appearing in the equations, tests were conducted to determine fully developed velocity distributions for air flowing without heat transfer in a smooth tube. The results are correlated by using conventional velocity and distance parameters, and agree closely with those of Nikuradse and other investigators. The analysis is extended to include flow with heat transfer, and equations for this case are obtained for Prandtl number of 1 in which the effects of the variation of fluid properties due to temperature variation across the tube were considered. By use of the equations for velocity and temperature distributions, relations are also obtained among Nusselt number, Reynolds number, and friction factor for a fluid with a Prandtl number of 1 for the case where the variation of fluid properties across the tube is large. The trends predicted analytically were found to be similar to those determined experimentally by measurement of average surface heat-transfer coefficients and friction factors of air flowing in tubes.
Displacement Versus Time Characteristics of Hydraulic Actuators
Authors: Linderoth L. Sigfred
Published: July 2022

This paper develops the relation between the displacement and time of a piston in a hydraulic actuator in terms of the load, mass, pressure drop, viscosity, and special operating conditions. It is based upon the Fanning law of friction in pipes and the value of the friction factor in smooth pipes as given by Hagen-Poiseuille and Blasius. The relation developed will cover most conditions met in the design of hydraulic equipment and will suggest a means to analyze those conditions not covered. This method is valid for pressures up to 100 atm and, with modifications, to higher pressures.
Cyclone-Fired Pressurized Steam Generator
Authors: Newkirk Merle
Published: July 2022

The Dow Chemical Company has a number of plants in the United States and Canada for the manufacture of industrial and pharmaceutical chemicals and the production of magnesium metal. Their power plants supply process, high-pressure, low-pressure, and vacuum steam; electrical energy, compressed air, high and low-pressure water and stack gas. Several of the power plants are synchronized with public utilities. Power is purchased or sold depending upon the local conditions. This combination affords an opportunity to select and operate equipment beyond the scope of the average plant, and to put into use advanced ideas in power-plant design.
62,000-Hp Vertical Six-Nozzle Impulse Turbines for the Bridge River Hydrodevelopment
Authors: Boyle W. F. , White I. M.
Published: July 2022

Information is presented concerning the historical background of the vertical impulse-type turbines installed at the Bridge River hydrodevelopment of the British Columbia Electric Railway Company, Ltd. This plant is of wide interest since few similar installations have been made. Data are presented to disclose the reason for selecting the 6-nozzle vertical turbine in comparison with other impulse-type turbines.
The Manufacture of Small Ice
Authors: Field Crosby
Published: July 2022

Small ice may be defined as water frozen in the form of ribbons, strips, fragments, cubes, or relatively small pieces, whether regular or irregular in shape, or pieces compounded thereof, or compounded of crushed ice. With the exception of ice cubes frozen in the domestic electric or gas refrigerator, it is only at the beginning of its third decade of successful commercialization. The daily production of small ice is now a substantial tonnage, a growth from less than 10 tons per day at the time of the visit of the Metropolitan New York Section of the American Society of Refrigerating Engineers to the author’s first commercial plant in 1928 (1). Although the reasons for this growth will be mentioned briefly, this paper will be limited to an abbreviated description of the numerous developments of processes and machinery for freezing small ice, including those in commercial operation today. No mention will be made of the equally numerous methods of freezing large cakes of ice and then crushing, sawing, or grid or wire-melting them into small ice, the product of which has not been included in the production stated.
Carbide High-Velocity Turning
Authors: Fersing Leif
Published: July 2022

The term “carbide high-velocity turning,” has lately come into use to indicate higher turning speeds than heretofore have been considered economical or practical for machining steel. Turning speeds of 350 to 400 fpm were generally considered high, whereas today turning speeds for steel from 400 to 1400 fpm are actually used in production with great success. This paper deals with factors affecting turning of steel and presents measurements of chip temperatures, loads on tools, effect of chip breakers, and the effect of turning speeds on the quality of finished surfaces. Illustrations of tools in cut at surface speeds up to 2400 fpm are shown. Descriptions of instruments are included, together with references to parts now being machined in the “high-velocity turning range” in production.
Controller Settings for Optimum Control
Authors: Wolfe W. A.
Published: July 2022

When a controller is applied to a process, one set of problems that arises is the dynamic action of the controller. Problems of speed of return, stability, and accuracy of control are all involved. In a paper by J. G. Ziegler and N. B. Nichols, a method of adjusting a controller was described. This method introduced and used concepts of time lag and reaction rate to arrive at satisfactory settings for the controller. The purpose of this paper is to study the problem of optimum settings and to develop criteria for obtaining the settings. In particular, the Laplace transform will be applied to an idealized plant and the resulting equations solved for optimum conditions.
An Analysis of Helicopter Propulsion Systems
Authors: Johnson J. A. , Eustis R. H.
Published: July 2022

This paper presents an analysis of several primary lightweight torque and jet-reaction systems which have been contemplated for propulsion power. These systems are compared with the conventional engine now in use. The comparison is made on the basis of hovering endurance and maximum range at a forward speed of 75 mph for helicopters having the same gross weight.
The Liquid-Coupled Indirect-Transfer Regenerator for Gas-Turbine Plants
Authors: London A. L. , Kays W. M.
Published: July 2022

The advantages of a liquid-coupled indirect-transfer-type gas-turbine-plant regenerator relative to the conventional direct-transfer-type are described. The indirect system consists of two units, one a hot-gas-to-coupling-liquid exchanger, and the other a coupling-liquid-to-compressed-air heater, together with the necessary circulation system for the coupling-liquid. One of the liquid metal alloys possessing a high heat-transfer coefficient, a low freezing point, and a high boiling point might prove to be suitable as a coupling liquid. As an example, the sodium-potassium eutectic alloy might be practical. Design studies are presented to give an idea of the geometry of indirect-type regenerators for four different gas-turbine cycles. One of these cycles may be considered as typical of a conventional open-cycle central station or marine plant; the second is like the first only it is a closed-supercharged cycle; the third is a locomotive plant, and the fourth is an aircraft turboprop system. The principal conclusion reached is that, granting the successful development of a suitable coupling liquid, the indirect-type regenerator possesses so many advantages over the direct type that it may prove to be a strong competitor.
Determination of the Dynamic Coefficient of Friction for Transient Conditions
Authors: Gould G. G.
Published: July 2022

A numerical value cannot be assigned to the coefficient of sliding friction between two materials. For most friction-clutch and brake applications, the friction forces during the first 2 min of operation are of primary interest; however, during this time these forces do not remain constant even under otherwise steady operating conditions. Curves, derived from experimental data, are presented showing the behavior of friction during this transient period for many different combinations of friction materials and mating surfaces.
Fireside Deposits on Steam Generators Minimized Through Humidification of Combustion Air
Authors: Murphy Paul , Piper J. D. , Schmansky C. R.
Published: July 2022

Increasing the humidity of combustion air to at least 16 lb of water per 1000 lb of dry air has been found to reduce greatly fireside-deposit troubles in stoker-fired steam generators at the Delray Plant of The Detroit Edison Company. It is believed that by keeping the heating surfaces cleaner than normal, humidification will improve average boiler efficiency sufficiently to compensate thermally for the water added to the combustion air, leaving a pronounced gain in availability and lower maintenance. Humidification appears to decrease volatilization from the fuel bed, particularly of silicon compounds.
Developments in Spreader-Firing Wet Wood
Authors: Weigel A. S.
Published: July 2022

The spreader, with its ability to burn a wide range of coals, has been one of the most widely accepted stokers for many years. In recent years it has been increasing in popularity by demonstrating a natural ability to burn cellulose fuels. The same inherent characteristics which give the spreader fuel flexibility when burning coal, are proving to be equally effective in broadening its application to include among other cellulose fuels wet wood. Wet wood as a fuel is usually considered to be those refuse fuels which are by-product in the manufacture of lumber, pulp and paper, and naval stores. They take the form of hogged wood and bark, “spent” chips, and other wood wastes which fall within the size range and moisture content suitable for spreader firing.
The Prevention of Embrittlement Cracking
Authors: Berk A. A.
Published: July 2022

Data are presented to show that nitrate, quebracho tannin, and zero-caustic treatment have been applied successfully in stationary plants to prevent cracking in embrittlement-detector specimens. On one large railroad prevention of cracking in detector specimens has paralleled a spectacular decrease in boiler-seam cracking in locomotive engines. The principal conclusion from a survey of cracking in stationary boilers in the last 10 years is that embrittlement is not a frequent occurrence.
The Solubility of Quartz and Some Other Substances in Superheated Steam at High Pressures
Authors: Morey G. W. , Hesselgesser J. M.
Published: July 2022

An apparatus and method for determining the solubility of silica in superheated steam at high pressures are described. At 752 F (400 C), the solubility of quartz in steam increases from 1.0 ppm at 500 psi to 1548 ppm at 15,000 psi; at 932 F (500 C), the solubility increases from 4.3 ppm at 500 psi to 2596 ppm at 15,000 psi. The curves representing the solubility results at 752 F and 932 F cross at two pressures. Between these two pressures the solubility is greater at 752 F than at 932 F; below and above these pressures the solubility is greater at 932 F than at 752 F. This crossing is ascribed to the pressure-density relationships of water at the two pressures, which are affected by the proximity at 752 F of the critical point of water. When the solubility is plotted against the density of steam at each measured point, the curves do not cross, and the solubility at 932 F is greater than at 752 F. The solubilities of some other substances in superheated steam at high pressures are given also.
Stress and Deflection Tests of Steam-Turbine Diaphragm
Authors: Taylor V. C.
Published: July 2022

This paper gives the results of tests made on a high-pressure and a low-pressure steam-turbine diaphragm. These diaphragms were subjected to loads which were applied uniformly along a semicircular arc. Data were taken on the deflection, reaction distribution, and nozzle-vane stresses. The information derived from these tests is incorporated in a method for calculating diaphragm stresses and deflections.
High-Temperature Properties and Characteristics of a Ferritic Steam-Piping Steel
Authors: Rankin A. W. , Reich W. A.
Published: July 2022

With the considerable amount of turbine capacity now in operation and being built at the 1000 F and 1050 F levels, there is considerable incentive to develop a stronger ferritic steel for these temperatures. This paper presents a review of the high-temperature properties and manufacturing and heat-treating characteristics of a chromium-molybdenum-vanadium alloy. The authors’ company is utilizing this composition for turbine shells, valve casings, and steam leads at both 1000 F and 1050 F. This paper presents the characteristics of the piping form of this alloy. Corresponding properties and operating experiences are also presented on the chromium-free molybdenum-vanadium steel which preceded the chromium-molybdenum-vanadium composition.
Effect of Temperature of Entrained Fluid on the Performance of Steam-Jet Ejectors
Authors: Holton W. C. , Schulz E. J.
Published: July 2022

An investigation of the performance of small commercial single and two-stage steam-jet ejectors handling air and steam at temperatures to 1000 F was conducted under the sponsorship of the Heat Exchange Institute. The results of tests are expressed in terms of “entrainment ratio,” which is the ratio of the flow rate of gas at a given temperature to that of the same gas at a base temperature. Entrainment ratio was found to be a linear function of temperature. The test results given appear to be independent of pressure and of design characteristics of the ejectors tested. Therefore the plot of the variation of entrainment ratio with temperature is, within the limits of the test accuracy, thought to be applicable to any ejector system.
Turbojet-Engine Design for High-Speed Flight
Authors: Hurley W. V.
Published: July 2022

The flight mission which a proposed engine is required to fulfill exerts a marked influence on the basic engine design. Missions involving high flight altitudes and high flight speeds tend to throw this problem into sharp relief. Accordingly, this paper discusses the general engine-design problem to meet the requirements of such missions.
High-Speed Braking
Authors: Eksergian C. L.
Published: July 2022

In contrast with the era when the railroad-car tread brake was adequate for all demands, the car brake of today must meet increases in speed of 33 per cent, axle load 25 per cent, inertia load 100 per cent, including 50 per cent overload, and deceleration 100 per cent. The advent of the “disk brake” has made it possible to meet these drastic requirements. This paper deals with the theoretical considerations as well as the practical application of the disk brake to modern railroad practice.
Recirculation in Cooling Towers
Authors: Lichtenstein Joseph
Published: July 2022

After defining recirculation, the paper shows it is a characteristic of the surroundings of a cooling-tower installation and must be considered by the user in his economic calculations and by the manufacturer for the proper selection of a cooling tower to reach a specified cold-water temperature. A knowledge of recirculation factors of installations can be obtained experimentally only by co-ordinated over-all tests on actual cooling-tower installations. The paper develops the methods and equations required for such tests to find the recirculation factor. It then shows how the cold-water temperature is affected by various degrees of recirculation, and how the size of a cooling tower would have to vary, if the cold-water temperature is fixed. Finally, the variation of cold-water temperatures with varying wet-bulb temperatures is studied for a series of fixed recirculation factors, and it is shown that if the recirculation factor increases with decreasing wet-bulb temperatures, a nearly constant cold-water temperature all year round may result.
Operating Experience With Cooling Towers in the Central Gulf Area
Authors: Hiebeler H. G.
Published: July 2022

The author’s company has had experience with both forced-draft and induced-draft cooling towers at four of its stations over a period of 12 years. He gives in some detail the experience with component parts of the systems, and indicates the direction in which improvements can be made.
Metastable Flow of Saturated Water
Authors: Bailey J. F.
Published: July 2022

This paper discusses the nature of the flow of saturated and nearly saturated water into regions where the pressure is less than the saturation pressure. It presents a method of computing the mass rate of flow through orifices and nozzles which is based on the rate of evaporation from a metastable liquid core into a surrounding ring of vapor. The flow rates for orifices are predicted accurately, and rates for nozzles are predicted to within 10 per cent. The analysis is based upon experimental investigations and is restricted to adiabatic flow conditions.
Modern Mercury-Unit Power-Plant Design
Authors: Hackett H. N. , Douglass Dwight
Published: July 2022

This paper outlines briefly the general theory of mercury-binary cycle efficiency, how it works, and the more usual types of applications where it may be used. The use of the mercury-steam cycle as applied to topping plants is explained more completely with the relative capabilities of 140 psig mercury and 2300 psig steam for such service specifically compared. As a typical, as well as the most recent application of a mercury topping unit, the new 15,000-kw mercury-unit power-plant equipment recently installed at the South Meadow Station of the Hartford Electric Light Company is dealt with in considerable detail. In the manufacture of the mercury-boiler parts, factory prefabrication of relatively large mercury-furnace wall sections was successfully done for the first time. The new 15,000-kw mercury plant has been in operation since February 1, 1949, and for the month of February produced 20,000,000 kwhr of electric power at an average fuel rate of 10,200 Btu per net kwhr.
Project Study for the Mitigation of Marine Fouling
Authors: Patten I. A.
Published: July 2022

The growth of marine organisms with resultant fouling of aquatic vessels and tunnel structures, throughout the years, has presented the utility engineers with a problem the effect of which creates lower efficiencies and higher maintenance costs. Mitigation of such growth and fouling on several occasions has been studied by industrial engineers and biologists. The result of such studies indicates Mytilus are the most difficult to control. The paper is a résumé of experiments and the development of a chlorine program which to date has proved effective and economical.
History and Performance of the Oil-Refinery Steam-Electric Generating Stations of the Pacific Gas and Electric Company
Authors: Estcourt V. F.
Published: July 2022

Design and operating characteristics are given for the three 1400-psi 940 F steam-electric generating stations built by the Pacific Gas and Electric Company for furnishing process steam and electricity to the three adjacent oil refineries, in addition to generating firm power for its own transmission system. An analysis is made of a number of special problems peculiar to this sort of undertaking, and both the advantages and limitations are discussed and evaluated, with emphasis upon the factors which must be considered in order to gain the maximum benefits from such a joint venture. It is pointed out that this type of plant can deliver the refinery’s variable requirements for process steam without materially affecting the ability to generate firm power at high thermal efficiencies. However, high-sulphur fuels require higher exit-gas temperatures in order to avoid air-preheater corrosion, with resultant lower boiler efficiencies.
Heat-Rate Test Results of the 100,000-Kw Essex Turbine Generator
Authors: Renton Vinal S. , Neal Stanford
Published: July 2022

A 3600-rpm, tandem compound, 100,000-kw turbine generator was recently installed at the Essex Generating Station of the Public Service Electric and Gas Company of New Jersey. Since it was, at that time, the largest machine of its type ever built, the first of a new class, and had initial steam conditions of 1250 psig and 1000 F, careful and extensive heat-rate tests were made jointly by the operating company and the manufacturer. The paper presents the results of the tests as an example of progress made in power-generating equipment.
High-Pressure Vessels in Coal-Hydrogenation Service
Authors: Donovan J. T. , Josenhans M. , Markovits J. A.
Published: July 2022

The converters have to be built to resist 10,000 psi pressure and 1000 F temperature, complicated by hydrogen attack and H2S corrosion. The three different designs proposed by American manufacturers are compared, and the vessels accepted for the plant are described in detail. The German spirally wound construction is discussed, and its expected advantages are enumerated.
High-Pressure (10,300 Psi) Piping, Flanged Joints, Fittings, and Valves for Coal-Hydrogenation Service
Authors: Sandaker J. H. , Markovits J. A. , Bredtschneider K. B.
Published: July 2022

The high-pressure piping components used in the coal-hydrogenation process are described briefly. Some factors considered in design are given. In addition, a short discourse on future design for commercial-scale plants is included.
The Influence of Shape of Cross Section on the Flexural Fatigue Strength of Steel
Authors: Dolan T. J. , McClow J. H. , Craig W. J.
Published: July 2022

It is not generally known or recognized that the flexural fatigue strength of a beam may be influenced to an appreciable extent by the shape of cross section of the member. In order to obtain further information on the magnitude of this shape effect, flexural fatigue tests were made employing four different shapes of cross section for each of two different steels. The results of these tests are compared and analyzed to clarify or explain some of the shape factors that may be of importance in affecting fatigue behavior. It is concluded that variations in residual stress or alterations of properties due to method of machining the different shapes play only a minor part in affecting the relative endurance limits. The susceptibility to localized inelastic action as governed by the shape of cross section and by the presence of “sore spots,” such as outward projecting corners, are tentatively believed to be the primary elements leading to the differences noted in flexural fatigue strengths.
Selection of Steam Conditions for No. 4 Unit—Riverside Generating Station
Authors: Dannettel R. C. , Harris G. S.
Published: July 2022

In the summer of 1948, the Consolidated Gas Electric Light and Power Company of Baltimore ordered a 75,000kw-capability, 3600-rpm, straight-condensing unit for installation as No. 4 Unit in its Riverside Generating Station. This selection was made after consideration of units both for straight-condensing and reheat cycles and was based upon judgment that the nonreheat unit should be more economical in total dollar costs to the company during the life of the unit.
A Comparison of Costs of Reheat Versus Nonreheat for 100-Mw Units
Authors: Moore R. P.
Published: July 2022

This paper analyzes the differences in cost of the various elements of a steam-electric power plant, as affected by choice of the reheat or nonreheat cycle applied to units of about 100,000-kw capability.
Experimental Technique in Pressure-Vessel Testing
Authors: Kooistra L. F. , Blaser R. U.
Published: July 2022

The latest designs of pressure vessels for high-pressure boiler service have been investigated by means of experimental stress analysis and hydraulic fatigue tests. Methods have been developed to measure strain on the inside as well as on the outside of pressure vessels under internal pressure. Pulsating hydraulic fatigue tests were conducted on full-scale high-pressure drums. Scale-model vessels of about one tenth actual size were similarly tested in a saturated-steam and water atmosphere of 2000 psi. The technique used in these tests, and the special apparatus built for the purpose are described.
Determination of ASME Nozzle Coefficients for Variable Nozzle External Dimensions
Authors: Folsom R. G.
Published: July 2022

Specifications for ASME long-radius nozzles do not include external dimensions. A series of tests have been made in an 8-in. pipe to determine the influence of the external nozzle diameter on pressures measured at several points downstream from the nozzle flange. The results are expressed in terms of per cent of the differential head measured at the standard corner tap locations.
Heat-Transfer Rates in Centrifugal Compressors and the Effect of Internal Liquid Cooling on Performance
Authors: Trumpler W. E. , Frederick R. W. , Trumpler P. R.
Published: July 2022

This paper makes a preliminary exploration of the cooling rates which may be obtained in the internal passages of a centrifugal compressor. A mechanism for such calculations is proposed, data are given and correlated, and the results are used for prediction of performance of a compressor pumping 7500 cfm air to 100 psi, assuming various cooling arrangements.
The Hydrodynamic Lubrication of Cyclically Loaded Bearings
Authors: Simons E. M.
Published: July 2022

The results of an experimental investigation of lubricating-film thicknesses in a journal bearing subjected to various loading conditions are presented and compared with theoretical predictions. General agreement with the theory has been found, except in the important cases of rotating and sinusoidally alternating loads applied at one half the frequency of shaft rotation. Here, instead of the theoretical eccentricity ratio of unity, finite film thicknesses have been observed. Free whirling in an unloaded bearing has been found to occur at slightly less than one half the shaft speed. High steady loads, high shaft speeds, and low lubricant viscosities have been found to inhibit journal whirl. The dependence of eccentricity ratio upon the extent of film rupture has been demonstrated for steady loads.
The Gas-to-Gas Heat Exchanger as Applied to an Oxygen Plant: Plate and Interrupted Strip-Fin Design
Authors: Simpelaar Clyde , Aronson David
Published: July 2022

The construction and performance of high-efficiency (95 per cent) counterflow heat exchangers is reported. These exchangers are of the finned-plate type employing interrupted strip fins. Comparison is made between test-core results and performance of large-size units installed in a tonnage gaseous-oxygen plant. Heat-transfer results were in good agreement but measured pressure drops on the large-size units were considerably higher than predicted from test-core results, possibly due to losses at end connections. Successful development of the true counter-flow gas-to-gas exchanger adds flexibility to the design of low-pressure gas cycles as in oxygen plants, permitting the substitution of heat exchangers for regenerators.
Design of Regenerators for Gas-Turbine Service
Authors: Aronson David
Published: July 2022

This paper presents a method for designing gas-turbine regenerators with particular reference to the condition of space being the principal limitation on design. For the plate-fin structure a procedure is given for arriving at maximum performance attainable in a given volume of regenerator core, and for calculating the fin patterns and plate spacings required to obtain such maximum performance. For the tubular-type regenerator a method of arriving at optimum tube spacings is presented.
Correlation of Plastic Deformation During Metal Cutting With Tensile Properties of the Work Material
Authors: Lapsley J. T. , Grassi R. C. , Thomsen E. G.
Published: July 2022

An experimental correlation of plastic deformation occurring during metal cutting with the plastic deformation in tension of the work material; an analysis permitting comparison of these two states of strain is presented. Orthogonal cutting of seamless steel tubing was employed for feeds of 0.0025–0.0085 in. per revolution (ipr), and positive rake angles of 25–45 deg. Deformation and forces of cutting were obtained from chip measurement and from a tool dynamometer employing resistance strain gages. The agreement obtained indicates that the tensile properties of the work material may offer a useful index to metal-cutting performance.
Improved Nails: Their Driving Resistance, Withdrawal Resistance, and Lateral Load-Carrying Capacity
Authors: Stern E. George
Published: July 2022

Approximately 3600 tests were performed on the driving resistance, withdrawal resistance, lateral load-carrying capacity, withdrawal, and deformation of 2, 2½, 3, 3½, and 4-in-long plain-shank, spirally grooved, and annularly grooved nails in southern yellow pine, white oak, and beech, in order to make available comparative test and design information on these nails. Data on nail properties, as influenced by nail type, size, point, shank pilot, steel composition, heat-treatment, cement coating, wood species, wood density, and annual rings of the wood are presented to help in determining the type of nail most suitable for specific applications. At a later date a report will be issued on the effects of change in moisture content and elapsed time after driving, on the foregoing test variables, since these factors could not be investigated until after the test planks had been air-seasoned. Such a study was made possible because all nails for tests on withdrawal resistance and lateral load-carrying capacity were driven at that time of test performance when oak and beech were green and pine was partially air-dry.
Possibilities of the Regenerative Steam Cycle at Temperatures Up to 1600 F
Authors: Knowlton P. H. , Hartwell R. W.
Published: July 2022

The regenerative-steam-cycle heat-rate gains that may be realized at temperatures up to 1600 F are presented in this paper. These gains are calculated for a theoretical cycle and also for a practical cycle wherein such losses as extraction-piping pressure drop, heater-terminal temperature differences, and the like, are considered. An economic evaluation of the anticipated turbine heat-rate differences for various throttle conditions is presented. This evaluation includes such factors as fuel costs, load characteristics, auxiliary-power requirements, boiler efficiencies, and annual fixed charges. A method of comparing the heat-rate gains due to higher steam temperatures with those made possible by resuperheating is provided.
Latest Technique for Quick Starts on Large Turbines and Boilers
Authors: Falkner J. C. , Napier D. W. , Kellstedt C. W.
Published: July 2022

The first quick starts made on the 1200-psi 900 F topping turbines at the Waterside Station were described in a paper presented in June, 1947. The purpose of the present paper is to review the high lights of the earlier presentation and to relate the developments since then.
Measurement of Temperatures in High-Velocity Steam
Authors: Murdock J. W. , Fiock E. F.
Published: July 2022

The demand for more accurate values of thermal efficiencies in modern steam power plants, together with the fact that the velocity of steam is often so high that the impact effect upon temperature-measuring instruments can no longer be neglected, has created a need for improved temperature instrumentation. Studies have been made of the performance, in moving air and steam, of various total-temperature-type wells suitable for use in steam at operating conditions. The instruments recommended for such applications, constructed so that the sensing element is surrounded by nearly stagnant steam, have temperature-recovery factors above 0.9, which do not change significantly with either the medium, its temperature, or its pressure. Although additional work remains to be done on reducing their sensitivity to flow direction and pattern, these wells, when installed in straight pipes through which steam is flowing at any velocity up to 725 fps, yield total enthalpies which are accurate to within 1 Btu per lb.
Relay Servomechanisms: The Shunt-Motor Servo With Inertia Load
Authors: Rogers T. A. , Hurty W. C.
Published: July 2022

This paper develops the theory of the shunt-motor relay servomechanism in terms of dimensionless motor parameters. Operating curves are drawn in the phase plane illustrating the effect of parameter changes on the stability of the servo for three forms of input signal. The first two forms of input signal, a step function and a uniform variation with time, have been discussed before and are included only for completeness. The third form of input signal, a sine function, is of most interest and is treated at greater length. The phase-plane curves, obtained from a differential analyzer, show three modes of operation which have been related to the servomechanism parameters by a relatively simple expression.
Bayesian estimations of dissipation, sound speed, and microphone positions in impedance tubes
Authors: Chen Ziqi , Xiang Ning , Fackler Cameron J.
Published: August 2022

Sound speed, microphone positions, and tube wall dissipation are critical parameters for absorption and impedance measurements using the transfer-function method in an impedance tube. This work applies a Bayesian method, based on a reflection coefficient model of an air layer and a boundary layer dissipation model, to estimate the values of these parameters for tube measurements. This estimation is based on experimental measurements obtained in the empty impedance tube with a rigid termination. Analysis results demonstrate that this method is able to accurately estimate the dissipation coefficient, the sound speed, and the microphone positions for highly accurate tube measurements.
Supplemental Material: How headward erosion breaches upstream paleolakes: Insights from dated longitudinal fluvial terrace correlations within the Sanmen Gorge, Yellow River
Authors: Liang Hao , al. et
Published: July 2022

Text: Lithostratigraphy; field sampling, methods, and pretreatments; terrace description in basin area. Table S1: Established ages of the Chinese loess-paleosol sequence. Table S2: Geographic information for terrace strath locations in the Sanmen Gorge. Table S3: Geographic information for erosional landform locations in the Sanmen Gorge. Figure S1: Total dose (De) distributions for OSL samples. Figure S2: Luminescence signals and decay curves of OSL samples. Figure S3: Photos of fluvial landforms and deposits.
Supplemental Material: Late Permian-Triassic ridge subduction beneath the northeastern margin of the North China Craton: Evidence from the Kaiyuan appinitic to high-Mg intermediate intrusions in northern Liaoning, North China
Authors: Yuan Lingling , Zhang Xiaohui , al. et
Published: August 2022

Mineral chemical, geochronological, whole-rock elemental and zircon Hf isotopic compositions (Tables S1–S4), zircon CL images (Figs. S1 and S2), element mobility checking (Fig. S3) for the Late Permian to Triassic appinitic and high-Mg dioritic intrusions from the Kaiyuan region of northern Liaoning, North China, and modeling parameters for Figure 13 (Table S5).
Successful use of intravenous treprostinil as a bridge to pulmonary thromboendarterectomy
Authors: Cattran Ashley , Elwing Jean
Published: July 2022

Chronic thromboembolic pulmonary hypertension (CTEPH) involves non-resolving thromboemboli in the pulmonary arteries. Treatment for CTEPH includes lifelong anticoagulation and determination of patients who have disease which is operable versus inoperable. Pulmonary arterial hypertension (PAH) targeted therapies are oftentimes used as a bridge to pulmonary thromboendarterectomy (PTE), though riociguat is the only Food and Drug Administration (FDA)-approved therapy for CTEPH. There is a paucity of data regarding the efficacy of other PAH therapies, particularly as a bridge to PTE. Here, we present a case report of severe CTEPH related to ventriculoatrial shunt in which intravenous treprostinil was used as a bridge to PTE.
Osteosynthesis in femoral neck fracture in two patients with ipsilateral lower limb amputation
Authors: Singh Deepak , Dhammi Ish Kumar , Jain Archit , Shahi Pratyush , Kumar Saurabh , Bansal Kuldeep
Published: July 2022

Femoral neck fracture in lower limb amputees poses treatment problems. The altered biomechanics of the hip in amputees, stump length, associated osteoporosis and difficulty in positioning these patients on the operation table are few of the technical challenges faced by an operating surgeon especially while salvaging the native hip joint. We report a case series of two lower limb amputee patients with fracture neck of femur in whom we salvaged the native hip joint by performing osteosynthesis. We observed satisfactory results of osteosynthesis in both of our patients on follow-up, with both achieving pretrauma ambulatory status in 6–8 weeks postoperatively. We concluded that each lower limb amputee patient with fracture neck of femur should be carefully evaluated on presentation and managed individually. These patients can be positioned and managed by osteosynthesis on a standard operating table or fracture table without requiring any special operating theatre set-up (traction devices).
Lipomatosis and optic neuropathy clinches the diagnosis of myoclonic epilepsy with ragged red fibres (MERRF) syndrome
Authors: Jeeva-Patel Trishal , Freund Paul , Margolin Edward A
Published: July 2022

We present a rare case of myoclonic epilepsy with ragged red fibres with high level of heteroplasmy presenting with optic neuropathy and a rare phenotype of lipomatosis. Cutaneous lipomas are typically thought of as a benign/isolated entity and this case emphasises importance of considering mitochondrial disease in all patients with lipomatosis especially in the presence of other systemic abnormalities.
Thoracoabdominal actinomycosis associated with laparoscopic cholecystectomy and mimicking metastatic pulmonary malignancy
Authors: Thapa Kriti , Sarker Moumita , Graman Paul
Published: July 2022

Actinomyces naeslundiiis rarely isolated in cases of actinomycosis. We present a case of thoracoabdominal actinomycosis caused by inadvertent enterotomy and gallstone spillage during a laparoscopic cholecystectomy. The actinomycosis initially presented as recurrent episodes of pneumonia, shortness of breath and unintentional weight loss. Initial CT imaging demonstrated pleural thickening along the right lung base as well as ill-defined consolidation in the right lower lobe. Repeat CT imaging showed progression of the mass-like region of consolidation with extrapulmonary spread to involve the abdomen, retroperitoneum and retrohepatic areas. Treatment involved intravenous antibiotics with concurrent abscess drainage followed by oral antibiotics.
Does completion of radical hysterectomy improve oncological outcomes of women with clinical early-stage cervical cancer and intraoperative detection of nodal involvement?: protocol for a systematic review and meta-analysis
Authors: Hu Cui , Xu Yu , Zhang Qianwen , Liu Qing , Du Yi , Jia Ya , He Yue-Dong , Zheng Ai , Xu Hui , Cui Shuang-Shuang , Tian Yong , Ran Lin , Ke Fengmei
Published: July 2022

Introduction

The management of women with clinical early-stage cervical cancer and lymph node involvement detected intraoperatively is heterogeneous and controversial. This paper presents the protocol of a systematic review and meta-analysis regarding the management of this specific population of patients. This proposed study aims to answer the question: does completion of radical hysterectomy improve the oncological outcomes of women with clinical early-stage cervical cancer and intraoperatively detected nodal involvement?

Methods and analysis

This protocol is drafted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines, and the proposed study will be conducted in accordance with the standard guidelines of ‘Preferred Reporting Items for Systematic Reviews and Meta-Analyses’ and ‘Meta-analysis of Observational Studies in Epidemiology reporting guideline’. Comprehensive literature searches will be performed in PubMed, Embase, Scopus, and Web of Science. The screening of the eligible studies, the extraction of data of interest, and the quality assessment of the included studies will all be independently performed by different members of our team. The primary outcome of this proposed study will be comparing the risk of recurrence or death from cervical cancer and the risk of all-cause death in patients with two different treatments (completion of radical hysterectomy or abandonment of radical hysterectomy); the secondary outcome of this proposed study will be comparing the risk of the grade 3/4 toxicities associated with the two types of management. Given the clinical heterogeneity among the included studies, data on outcomes will be pooled by random-effects models. Heterogeneity will be evaluated using the I2 statistic. The risk of bias for the included studies will be evaluated using the Newcastle-Ottawa Scale or the Cochrane collaboration’s tool. The grade of evidence will be evaluated by two independent members of our team using the Grading of Recommendations, Assessment, Development and Evaluations approach.

Ethics and dissemination

Ethical approval is not required because there will no primary data collected. The findings of this proposed study will be published in an international peer-reviewed journal.

PROSPERO registration number

CRD42021273527.
Impact of the national health guidance intervention for obesity and cardiovascular risks on healthcare utilisation and healthcare spending in working-age Japanese cohort: regression discontinuity design
Authors: Fukuma Shingo , Mukaigawara Mitsuru , Iizuka Toshiaki , Tsugawa Yusuke
Published: July 2022

Objectives

Increases in obesity and cardiovascular diseases contribute to rapidly growing healthcare expenditures in many countries. However, little is known about whether the population-level health guidance intervention for obesity and cardiovascular risk factors is associated with reduced healthcare utilisation and spending. The aim of this study was to investigate the effect of population-level health guidance intervention introduced nationally in Japan on healthcare utilisation and spending.

Design

Retrospective cohort study, using a quasiexperimental regression discontinuity design.

Setting

Japan’s nationwide employment-based health insurers.

Participants

Participants in the national health screening programme (from January 2014 to December 2014) aged 40–74 years.

Predictors

Assignment to health guidance intervention (counselling on healthy lifestyles, and referral to physicians as needed) determined primarily on whether the individual’s waist circumference was above or below the cut-off value in addition to having at least one cardiovascular risk factor.

Primary and secondary outcome measures

Healthcare utilisation (the number of outpatient visits days, any medication use and any hospitalisation use) and spending (total medical expenditure, outpatient medical expenditure and inpatient medical expenditure) within 3 years of the intervention.

Results

A total of 51 213 individuals within the bandwidth (±6 cm of waist circumference from the cut-off) out of 113 302 screening participants (median age 50.0 years, 11.9% woman) were analysed. We found that the assignment to the national health guidance intervention was associated with fewer outpatient visit days (−1.3 days; 95% CI, −11.4 to −0.5 days; p=0.03). We found no evidence that the assignment to the health guidance intervention was associated with changes in medication or hospitalisation use, or healthcare spending.

Conclusion

Among working-age, male-focused Japanese from a health insurer of companies of civil engineering and construction, the national health guidance intervention might be associated with a decline in outpatient visits, with no change in medication/hospitalisation use or healthcare spending.