bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensory sensitivity after acquired brain injury: A systematic review
Authors: Thielen Hella , Tuts Nora , Welkenhuyzen Lies , Huenges Wajer Irene M. C. , Lafosse Christophe , Gillebert Céline R.
Published: July 2022

Patients with acquired brain injury frequently report experiencing sensory stimuli as abnormally under‐ (sensory hyposensitivity) or overwhelming (sensory hypersensitivity). Although they can negatively impact daily functioning, these symptoms are poorly understood. To provide an overview of the current evidence on atypical sensory sensitivity after acquired brain injury, we conducted a systematic literature review. The primary aim of the review was to investigate the behavioural and neural mechanisms that are associated with self‐reported sensory sensitivity. Studies were included when they studied sensory sensitivity in acquired brain injury populations, and excluded when they were not written in English, consisted of non‐empirical research, did not study human subjects, studied pain, related sensory sensitivity to peripheral injury or studied patients with a neurodegenerative disorder, meningitis, encephalitis or a brain tumour. The Web of Science, PubMed and Scopus databases were searched for appropriate studies. A qualitative synthesis of the results of the 81 studies that were included suggests that abnormal sensory thresholds and a reduced information processing speed are candidate behavioural mechanisms of atypical subjective sensory sensitivity after acquired brain injury. Furthermore, there was evidence for an association between subjective sensory sensitivity and structural grey or white matter abnormalities, and to functional abnormalities in sensory cortices. However, further research is needed to explore the causation of atypical sensory sensitivity. In addition, there is a need for the development of adequate diagnostic tools. This can significantly advance the quantity and quality of research on the prevalence, aetiology, prognosis and treatment of these symptoms.
Cutaneous adverse events following 771 doses of the inactivated and mRNA COVID‐19 vaccines: A survey study among health care providers
Authors: Bostan Ecem , Yel Beril , Karaduman Aysen
Published: July 2022

Introduction

As Coronavirus disease 19 (COVID‐19) still continues to affect humanity worldwide, different types of COVID‐19 vaccines are being administered to maintain immunization against COVID‐19. As both the inactivated and mRNA vaccines are now being applied prevalently, systemic adverse events along with cutaneous side effects are frequently being reported in the literature.

Aim

In our study, we aimed to determine the cutaneous adverse effects of the inactivated (Sinovac‐CoronaVac) and mRNA (Pfizer‐BioNTech) vaccines in healthcare providers in a tertiary referral hospital.

Methods

A web‐based survey consisting of 26 questions related to the systemic and cutaneous side effects of the inactivated and mRNA COVID‐19 vaccines, was formed. The online questionnaire was spread among the healthcare professionals working in a tertiary referral hospital via common instant messaging groups and e‐mail.

Findings

A total number of 234 participants were included in the study. One hundred fifty‐seven were female whereas 77 were male. The mean age was 31.51 years. Eighty‐nine respondents reported to have at least one cutaneous side effect after COVID‐19 vaccination. Most commonly observed cutaneous side effects were local injection site reactions. Pfizer‐BioNTech vaccine at the first and second doses, was shown to have statistically significantly higher rates of systemic and cutaneous adverse events compared to the Sinovac‐CoronaVac vaccine.

Results

Our study shows that both inactivated and mRNA COVID‐19 vaccines are associated with transient local injection site reactions, no severe systemic or cutaneous adverse events were observed in our study population.
Transcriptional and functional characterizations of multiple flagellin genes in spirochetes
Authors: Kurniyati Kurni , Chang Yunjie , Liu Jun , Li Chunhao
Published: July 2022

The flagellar filament is a helical propeller for bacterial locomotion. In external flagellates, the filaments are mostly homopolymers of a single flagellin protein. By contrast, the flagellar filaments of spirochetes are mostly heteropolymers of multiple flagellin proteins. This report seeks to investigate the role of multiple flagellin proteins using the oral spirochete Treponema denticola as a model. First, biochemical and genetic studies uncover that the flagellar filaments of T. denticola mainly comprise four proteins, FlaA, FlaB1, FlaB2, and FlaB3, in a defined stoichiometry. Second, transcriptional analyses reveal that the genes encoding these four proteins are regulated by two different transcriptional factors, sigma28 and sigma70. Third, loss‐of‐function studies demonstrate that each individual flagellin protein contributes to spirochete motility, but none of them is absolutely required. Last, we provide genetic and structural evidence that FlaA forms a “seam”‐like structure around the core and that deletion of individual flagellin protein alters the flagellar homeostasis. Collectively, these results demonstrate that T. denticola has evolved a unique mechanism to finely regulate its flagellar filament gene expression and assembly which renders the organelle with the right number, shape, strength, and structure for its distinct motility.
An autopsy case of amyotrophic lateral sclerosis with striatonigral and pallidoluysian degeneration and cat's‐eye‐shaped neuronal nuclear inclusions
Authors: Kon Tomoya , Mori Fumiaki , Kinoshita Iku , Nakamura Takashi , Nishijima Haruo , Suzuki Chieko , Goto Shintaro , Kijima Hiroshi , Tomiyama Masahiko , Wakabayashi Koichi
Published: July 2022

We report the case of a Japanese woman with sporadic amyotrophic lateral sclerosis (ALS) of 28 months’ duration who died at the age of 66 years. Postmortem examination revealed moderate loss of neurons and phosphorylated TDP‐43 (p‐TDP‐43)‐immunoreactive neuronal and glial cytoplasmic inclusions in the upper and lower motor neurons. Additionally, marked neuronal loss was observed in the neostriatum, globus pallidum, subthalamic nucleus, and substantia nigra. p‐TDP‐43‐immunoreactive inclusions were frequently found in these areas. Neuronal loss and TDP‐43 pathology in the motor, striatonigral, and pallidoluysian systems were predominant on the right side. Moreover, p‐TDP‐43‐immunoreactive cat's‐eye‐shaped neuronal nuclear inclusions (NNIs) were observed in the affected lesions. NNIs in the striatonigral system were also positive for valosin‐containing protein (VCP). We diagnosed the patient as having ALS with striatonigral and pallidoluysian degeneration. Patients with ALS rarely experience pallido‐nigro‐luysian degeneration. To our best knowledge, only one case of ALS combined with striatonigral and pallidoluysian degeneration has been reported. Neuronal loss in the striatonigral and/or pallidoluysian systems has also been reported in patients with ALS with multisystem degeneration accompanied by long‐term use of an artificial respirator. Based on these findings, a possibility of an extremely rare subtype of ALS demonstrating selective loss of neurons in the striatonigral and pallidoluysian systems exists; another possibility is that this type could be an early stage or forme fruste of ALS with multisystem degeneration. Although VCP‐positive cat's‐eye‐shaped NNIs have been reported in spinocerebellar ataxia type‐2 cases, our case report presents VCP‐positive NNIs in a patient with ALS for the first time.
Two magnesium transporters in the chloroplast inner envelope essential for thylakoid biogenesis in Arabidopsis
Authors: Zhang Bin , Zhang Chi , Tang Renjie , Zheng Xiaojiang , Zhao Fugeng , Fu Aigen , Lan Wenzhi , Luan Sheng
Published: July 2022

Magnesium (Mg2+) serves as a cofactor for a number of photosynthetic enzymes in the chloroplast, and is the central atom of the Chl molecule. However, little is known about the molecular mechanism of Mg2+ transport across the chloroplast envelope.

Here, we report the functional characterization of two transport proteins in Arabidopsis: Magnesium Release 8 (MGR8) and MGR9, of the ACDP/CNNM family, which is evolutionarily conserved across all lineages of living organisms.

Both MGR8 and MGR9 genes were expressed ubiquitously, and their encoded proteins were localized in the inner envelope of chloroplasts. Mutations of MGR8 and MGR9 together, but neither of them alone, resulted in albino ovules and chlorotic seedlings. Further analysis revealed severe defects in thylakoid biogenesis and assembly of photosynthetic complexes in the double mutant. Both MGR8 and MGR9 functionally complemented the growth of the Salmonella typhimurium mutant strain MM281, which lacks Mg2+ uptake capacity. The embryonic and early seedling defects of the mgr8/mgr9 double mutant were rescued by the expression of MGR9 under the embryo‐specific ABI3 promoter. The partially rescued mutant plants were hypersensitive to Mg2+ deficient conditions and contained less Mg2+ in their chloroplasts than wild‐type plants.

Taken together, we conclude that MGR8 and MGR9 serve as Mg2+ transporters and are responsible for chloroplast Mg2+ uptake.
Species–genetic diversity correlations depend on ecological similarity between multiple moorland plant species
Authors: Ishii Naohiro I. , Hirota Shun K. , Matsuo Ayumi , Sato Mitsuhiko P. , Sasaki Takehiro , Suyama Yoshihisa
Published: July 2022

Species diversity (SD) and genetic diversity (GD) are fundamental aspects of biodiversity and are dependent because they are sympatrically affected by biotic and abiotic factors. Species–genetic diversity correlations (SGDCs) range from positive to negative among multiple focal species even across same communities. As determinant mechanisms of SGDCs, previous studies identified neutral processes related with habitat size and connectivity, environmental filtering and interspecific interactions. Theoretically, similar responses of SD and GD to these mechanisms can lead to positive SGDCs. The quantitative evaluation and comparison of similarity in each mechanism have not been performed. Here, we tested whether α‐ and β‐SGDCs could be determined by similarity in ecological characteristics (ecological similarity), such as environmental responses (responses of GD to moorland area, altitude, pH, electric conductivity and spatial autocorrelation based on regression analysis), dispersal ability (seed dispersal and pollination mode) and functional traits associated with competitions (leaf height, leaf size and specific leaf area (SLA)). We investigated SD and GD of 11 species based on single nucleotide polymorphisms across 20 moorland plant communities in northern Japan, and evaluated correlations between SGDCs and principal components of the ecological characteristics across the focal species. α‐SGDCs varied from positive to negative, which was explained by ecological similarity in the response of GD to pH, seed dispersal and pollination mode, leaf height and SLA. In contrast, β‐SGDCs were almost consistently positive, which resulted from spatial autocorrelation and could not be explained by ecological similarity. We emphasized that not only environmental filtering and neutral process via dispersal limitation but also competitions can contribute to SGDCs. The incorporation of trait‐based approaches is effective for understanding spatial patterns of combinations of SD and GD. Evaluating SGDCs and spectrums of functional traits highly related to community assembly may lead to spatial predictions of GD in whole members of communities.
An explanatory spatio‐temporal pattern analysis of the fruit industry in Xinjiang, China, between 1988 and 2017
Authors: Ilniyaz Osman , Du Qingyun , Kurban Alishir , Kasimu Alimujiang , Azadi Hossein
Published: July 2022

Awareness of spatio‐temporal patterns in the fruit industry is important for planning planting structures and improving yield. Xinjiang is famous for its fruit because of their unique natural features. However, overall quality and yields lag behind international and national levels owing to technological and economic limitations. Using seven perennial fruits, this study investigated the spatio‐temporal features and trends in the Xinjiang fruit industry during the period 1988–2017. The best‐fitting regression models of fruit production, determined by Akaike's information criterion, revealed improvements over these years. Spatial autocorrelation and comparative advantage analyses revealed an expanding fruit industry in the south and east of Xinjiang and the fruit concentration in some areas revealed higher suitability than that in others. Natural conditions were the dominant factors affecting the suitability for fruit planting, whereas anthropological activities were the driving factors. Economic growth can promote yield efficiency when combined with better management, product composition, sort selection, and planting technologies.
Performance of the Periphery Pump
Authors: Iversen H. W.
Published: July 2022

The periphery-pump performance is analyzed in terms of shear stresses imparted to the fluid by the impeller. The resulting expressions include two shear coefficients and an average impeller velocity, which are determined experimentally. The analysis predicts the shapes of the performance curves of head, power, and efficiency as functions of the flow rate. The shear coefficients, and hence the pump performance, are shown to be functions of the impeller roughness, and of the flow channel area.
The Free-Piston-and-Turbine Compound Engine—A Cycle Analysis
Authors: London A. L.
Published: July 2022

A simplified cycle analysis is presented for a compound engine of the free-piston type. To allow ready algebraic formulation, the assumption of perfect-gas behavior with suitably averaged specific-heat magnitudes is employed. The influence of compressor, turbine, and mechanical “inefficiencies” as well as the effects of valve-pressure drops and coolant-jacket heat transfer are included. The calculated parameters of specific flow rate, specific fuel consumption, and turbine-inlet temperature are consequently realistic performance estimates, as shown by comparison with available test information. Results of the analysis clearly indicate the importance of component losses on turbine-inlet temperature and plant specific-fuel consumption and point out the unique characteristics of the cycle. Consideration also is given to the “supercharged-intercooled” and the “reheat” variants of the simple free-piston compound engine. A study of methods of load governing leads to the important conclusion that in order to realize a flat part-load economy characteristic, comparable to that of a diesel, it will be necessary to obtain a turbine design which achieves high part-load fuel efficiency. The reheat cycle has an excellent part-load fuel economy, but probably will require the use of a variable-area nozzle turbine.
Kinetic Theory of Evaporation Rates of Liquids
Authors: Lype Eric F.
Published: July 2022

The rate of evaporation of a liquid is calculated from the Polanyi-Wigner theory of the escape of molecules from the surface of a solid body. In particular, the rate of evaporation of a “pseudocrystalline” fluid, such as water, is obtained from Volmer’s extension of this theory to the case where the molecules escape only from isolated locations, creating holes in the surface. The rate of condensation on the surface of a pseudocrystalline fluid is obtained by applying the kinetic theory of gases to the case where condensation occurs only in the holes created by this process of evaporation. The energy of escape is in conformity with the virial theorem as applied to the Lennard-Jones-Devonshire equation of state. Mass and heat transfer calculated from these laws for phases of unequal temperatures, when applied to the pseudocrystalline substance water, agree closely with Jakob’s and Dergarabedian’s experiments on boiling water.
The Use of Additives for the Prevention of Low-Temperature Corrosion in Oil-Fired Steam-Generating Units
Authors: Huge E. C. , Piotter E. C.
Published: July 2022

Low-temperature corrosion has become an important consideration and presents a real problem in the design and operation of oil-fired steam-generating units. It is caused by the presence of sulphur trioxide in the combustion gases which unites with water vapor and forms sulphuric acid on the cooler surfaces of the unit. Various ways of combating this condition are discussed, with particular emphasis on the use of dolomite as an additive. Test data and the results of actual operating experience are presented which show that additives are effective in reducing the amount of acid formed and, in some cases, practically eliminating cold-end pluggage and corrosion. The economics of their use and the design of units for higher efficiency when using additives also are discussed.
Influence of Fine Particles on Corrosion of Economizer and Air-Preheater Surfaces by Flue Gases
Authors: Hodson Peter
Published: July 2022

Fine particles are those less than 10 microns in diameter and are often not detected as single particles by a light microscope. They have a very large relative surface area which tends to accelerate any reaction as well as increasing their ability to adsorb another substance. Flue-gas corrosion is caused by sulphur compounds and water vapor forming sulphuric acid which attacks iron to form ferric and ferrous sulphate. The former is a catalyst in the formation of sulphur trioxide from sulphur dioxide. Sulphur trioxide and ferric sulphate also raise the dew point. Fine particles consist of unburned fuel and ash spheres known as cenospheres or fragments of the latter. They increase the reaction rate as well as the condensation temperature and rate. They can attain a temperature lower than that of the gas stream by radiation and are good condensation nuclei. A qualitative test of the formation temperature, extent, and nature of deposits from cleaned and dirty gas showed that deposits tend to build up in a narrow range and that cleaning the gas greatly decreases the rate of deposit build-up.
The Hydrodynamic Pocket Bearing
Authors: Wilcock Donald F.
Published: July 2022

The low power loss of an externally pressurized pocket bearing is accompanied by dependence upon the reliability of the external pressure source. In this new hydrodynamic pocket-bearing design the required flows and pressures are generated by hydrodynamic action within the bearing. Power loss about half that for conventional thrust bearings is readily achieved. Preliminary operation on bearings of this design has been successful, indicating application in high-speed installations where low bearing loss is desirable, and in machines where a measurement of thrust may be useful. The bearing lends itself readily to a frictionless ball-seat mounting, and the principle may be applied to journal bearings.
Planning for Efficient Use of Manpower
Authors: Drake W. V. , Riley D. H.
Published: July 2022

When studying the factors affecting operating costs in steam-electric generating stations, it is almost superfluous to say that each system or company is unique in that it faces problems different, to a greater or lesser degree, from those of its neighbor. For in reality, the problems differ from station to station.

In discussing manpower and operating costs, it would be foolhardy, in an attempt to reduce factors at each station to the lowest common denominator for comparative purposes, to divorce each power station from its parent company. System or company-wide policies are important, if not the most important, factors which dictate the size of station crews.
Some Statistical Methods for Evaluation of Experimental Results
Authors: Pike E. W.
Published: July 2022

The statistician plays an important part in this machine age in which we live. Statistical examination of mass-production methods, for example, results in improvement, better quality control, and more uniformity of billions of dollars’ worth of industrial products produced each year by repetitive processes. This paper describes the logic and methods used in evaluating and organizing equipment tests.
Compressor Surge and Stall Propagation
Authors: Emmons H. W. , Pearson C. E. , Grant H. P.
Published: July 2022

Compressor surge is shown by the application of several types of instrumentation (notably a hot-wire anemometer) to consist of two distinct types of phenomena. The whole compressor flow system may be unstable in the manner of a self-excited Helmholtz resonator. The theory of this instability is presented and is shown to explain some of the observed pulsation symptoms. The stalling of the flow through the blade rows, which usually is assumed to be the origin of pulsation, is shown to occur in propagating groups of 1 to 5 regions involving from 2 to 20 blades each. The theory of this “stall propagation” shows the propagation velocity relative to the wheel to be dependent upon boundary-layer growth parameters and hence the frequency (relative to a stationary probe) to be proportional to the wheel speed. Another part of observed compressor pulsation thus is explained. These two phenomena frequently interact to produce complex performance characteristics. The theories presented are essentially correct as shown by experimental verification, but much remains to be done to make quantitative compressor-performance prediction practical.
Grinding Capacities of Cane-Sugar Mills
Authors: Cabrera Jose M.
Published: July 2022

This paper summarizes milling equipment in actual operation as listed in the “Gilmore Manuals for 1951,” for Cuba, Florida, Louisiana, and Hawaii, and for 1950, for Puerto Rico, Dominican Republic, and Haiti. Text with tabulations and graphs covers mill sizes, crusher types and arrangements, number of milling units in tandem, tonnage ground, sucrose in cane, fiber in cane, maceration employed; it includes various curves comparing the capacities and extraction by mill sizes, crushing arrangements, and other data pertinent to the task of grinding cane.
The San Bartolo Vertical Impulse Turbine
Authors: Fuentes Javier , Almanza Salvador , Rheingans W. J.
Published: July 2022

The San Bartolo Hydroelectric Station, which is part of the Miguel Aleman Hydroelectric System of the Comision Federal de Electricidad, Mexico, was designed to operate about six months a year, during the dry season. During the rainy season, water will be stored in the reservoir above this plant. Because of this intermittent operation, certain economies in the design and construction of the power plant were possible. The impulse turbine is a six-jet vertical unit which has certain advantages over a single-jet turbine, both in design and operating efficiency. Also, a vertical impulse turbine has a number of advantages over a horizontal unit, both in simplicity of design and in cost. The runner is of a unique design, in that it is integrally fabricated out of plate steel with the bucket bowls welded directly to the wheel disk, thus eliminating bucket bolts. A special needle-control mechanism permits operation of the turbine with any combination of six jets. The penstock shutoff valve consists of a rotary valve, which proved to be very satisfactory when tested in the shop.
Refrigerating-Plant Performance Characteristics by Electrical-Analog Analysis
Authors: Kayan Carl F.
Published: July 2022

The purpose of this paper is to develop a means for predicting over-all performance characteristics of an integrated machine and heat-transfer complex. To this end electrical-analog methods are applied to the study of refrigerating-plant performance.
The Dynamics of Filled Temperature-Measuring Systems
Authors: Muller-Girard Otto
Published: July 2022

The response equations of a two-time-constant interacting network as applied to liquid-filled tube systems are developed. The solutions to a unit step, ramp, and sinusoidal temperature input are given. Some practical aspects of response work based on experiments with mercury-filled thermal systems are presented and a few recommendations concerning the specification of the speed of response are included.
Application of High-Speed Strain-Gage Torquemeter to Turbomachinery Research
Authors: Buckner H. A. , Rebeske J. J.
Published: July 2022

In turbomachinery-component research, it is frequently impractical to obtain power measurements by conventional cradled dynamometers. This paper presents a description of a high-speed strain-gage torquemeter having the high accuracy required for this research and shows the application of this torquemeter to compressor and turbine setups. The paper also discusses pertinent factors for obtaining accurate measurements with the instrument.
Safe Stress Range for Deformation Due to Fatigue
Authors: Kawamoto M. , Nishioka K.
Published: July 2022

The safe stress range of materials for fatigue is determined from both fatigue destruction and fatigue deformation. On fatigue destruction there have been many investigations, hitherto, while on fatigue deformation only a few investigations have been made. The authors believe that the safe stress range, usually considered for fatigue deformation, is incorrect for some materials and discuss this matter as it was presented in their experiments.
The Thermal Design of Nuclear Power Reactors
Authors: Palladino N. J.
Published: July 2022

This paper presents the development of relationships between maximum fuel-element surface temperatures, coolant temperature rise, flow, pumping power, and operating steam temperatures for use in the design of a power-producing nuclear reactor. The heat output of a power-producing reactor is generally limited by the maximum metal-surface temperature which can be utilized without incurring excessive corrosion or dangerous conditions of boiling. The design of a reactor on the basis of maximum metal-surface temperature is particularly important in view of the fact that heat is not generated uniformly throughout the reactor and because of the fact that tolerances which must be established for manufacturing purposes may lead to further increases in hot-spot temperatures.
Graphical Representation of the Frictional Losses in Commercial Pipe of Air and Steam Flowing Turbulently at Low Pressure
Authors: Knapp W. C. , Metzger J. W.
Published: July 2022

Frequently, design investigations in the field of fluid flow require the rapid evaluation of pressure losses in pipes at various conditions of temperature and pressure. This discussion presents a graphical solution for determining frictional losses in pipes of various sizes carrying air and steam, together with the mathematical analysis from which it is evolved. Similar investigations carried out for other fluids may yield comparable graphical solutions, the utilization of which would aid materially in increasing the usefulness of fluid-flow data.
Dielectric Breakdown Properties of Thermosetting Laminates
Authors: Skow N. A.
Published: July 2022

Thermosetting laminated plastics are used extensively for electrical insulation because of their unusual combination of electrical, mechanical, and chemical properties. Excellent electrical insulators, these materials are also mechanically strong, light in weight, and easy to fabricate. They resist chemical corrosion, moisture, aging, heat, and temperature deterioration. To establish safe operating loads, tests for the endurance limits of dielectric strength were run on each of several grades of thermosetting plastic laminates plotting voltages against time. The data thus obtained indicate that for a given thickness and atmospheric condition, a maximum voltage exists below which failure will not occur. Tests of this type yield results which are valuable to the design engineer in determining the proper grade and thickness of material for use as insulating parts in electrical equipment.
Personnel and Equipment Cooling in Supersonic Airplanes
Authors: Makowski J. , Whitney V. L.
Published: July 2022

Cooling of crew compartments and electronic equipment becomes more important and, at the same time, more difficult as airplane speeds increase. A sharp increase in capacity required from the cooling system takes place when the surrounding air becomes too hot to be a convenient direct heat sink. The successful use of water vaporization permits the design of compact cooling units which satisfy the requirements of supersonic airplanes.
Some Structural Aspects of Thermal Flight
Authors: Gerard George
Published: July 2022

The trend of substantial increases in gross weight of modern high-performance aircraft designed for normal temperature operation is discussed. This trend has continued in spite of considerable improvements in physical properties of materials, more refined stress analyses, and improved fabrication techniques. With elevated temperatures as a consideration at Mach numbers greater than 2, the decrease in physical properties of materials will result in substantial weight increases due to this source alone. The evolution of thin-wing supersonic aircraft has resulted in a variety of proposed structural arrangements for wing and tail surfaces. The structural efficiencies of several designs are reviewed to indicate probable allowable compressive-stress levels. By use of probable stress levels, the efficiencies of various materials at elevated temperatures are considered for tension, compression, and shear components of the airframe. Based on such data, relative weight trends of aircraft designed for thermal flight are indicated. Additional considerations of life expectancy due to creep at elevated temperatures are presented.
Wind-Induced Vibration of a Pipe-Line Suspension Bridge, and Its Cure
Authors: Baird R. C.
Published: July 2022

This paper concerns a solution to a critical pipe-line bridge-vibration problem. The answer to the problem resulted from the application of scientific research methods. As the first step toward a solution, careful measurements were made which laid bare the fundamental cause of the trouble. Following this, several possible solutions were conceived, and the most practical appearing one was selected for testing. Dynamic tests on models were made to verify the choice and to aid in full-scale design. Finally, a full-scale aerodynamic vibration damper was applied to the suspension bridge and the results checked by scientific measurements. The resulting solution for preventing vibration of suspension bridges is thought to be completely new, and the subject pipe-line bridge, the first of its kind to which it has been applied.
Stresses From Local Loadings in Cylindrical Pressure Vessels
Authors: Bijlaard P. P.
Published: July 2022

A short discussion is given of the possible methods for computing the stresses caused in cylindrical shells by local loadings. It is concluded that the method of developing the loads and displacements into double Fourier series leads to formulas which are best suited for numerical evaluation. With this method the pertinent expressions for the displacements caused by radial loads are found by reducing the three partial differential equations of the shell theory to an eighth-order differential equation in the radial displacements, which is similar to, but not identical with, those derived by Donnell and Yuan. Insertion of the Fourier series for the radial displacements and the external loading in this equation leads directly to a double series expression of the radial displacement w in terms of the load factors Zmn of the radial load. This results in the pertinent expressions for the other displacements and for the bending moments and membrane forces. The cases of radial loading considered here and those which can be reduced to it are (a) a load uniformly distributed within a rectangle, (b) a point load, (c) a moment in the longitudinal direction, uniformly distributed over a short distance in the circumferential direction, (d) a moment in the circumferential direction, uniformly distributed over a short distance in the longitudinal direction. For all these loadings the load factors Zmn, which have to be used in the pertinent formulas for the displacements, bending moments, and membrane forces, are computed. For the case of tangential loading an eighth-order differential equation is derived in terms of the radial displacement and the tangential load. Using this equation, formulas for the displacements, bending moments, and membrane forces for tangential loading within a rectangle are found.
CO Boiler and Fluidized-Bed Steam Superheater on Sinclair Refining Company’s New Fluid Unit at the Houston Refinery
Authors: Campbell O. F. , Pennels N. E.
Published: July 2022

Approximately 400,000 lb per hr of 550-psig, 750 F total temperature steam production is a unique feature of Sinclair Refining Company’s new fluid catalytic-cracking unit at its Houston, Texas, Refinery. Over 300,000 lb per hr of 700-psig saturated steam are produced on the oil industry’s first direct-fired unit to recover both the sensible heat and the heat of combustion from the high-temperature regenerator-exit flue gas. The heat of combustion of the regenerator-exit flue gas is derived from its CO content. Saturated steam produced on the boiler is superheated to 750 F total temperature in industry’s first fluidized-bed respray steam superheater. The superheater-respray feature produces approximately 100,000 lb per hr of additional steam and allows simultaneous control of both the regenerator-bed temperature and the steam superheat.
The Application of Statistics to Simple Fixed-Gage Design
Authors: Charbonneau H. C.
Published: July 2022

Using as an example a simple fixed-gage design, the author explains the application of statistics to quality control. The methods of selecting and designing gages are considered—the bilateral and unilateral systems. How these tolerance theories may be applied and the results achieved are discussed at some length.
Secondary Flow in Axial-Flow Turbomachinery
Authors: Smith L. H.
Published: July 2022

A method is presented by which one can include the principal effects of secondary flow in the design of multi-stage axial-flow turbomachinery. The method uses the conventional axial-symmetry solution as a basic flow picture from which the induced turning and radial velocities characteristic to the secondary flow can be deduced. Frictional effects, such as the growth of boundary layers on the blades, are excluded from the analysis, but the disposition of the fluid which comes from boundary layers on the hub and casing surfaces upstream of a blade row can be accounted for in an approximate manner by assuming that the fluid is frictionless while in the blading. To get a first-order approximation of the secondary flow in a blade row, it is necessary to know only the number of blades in the row and the axisymmetric-flow solution. The principal assumption involved in this approximation is that the distortion of the flow surfaces due to the secondary velocities is small. The method is sufficiently accurate for predicting the secondary flows which occur as a result of nonuniform blade loading, but solutions for boundary-layer flows must be considered only qualitative because of the large flow-surface distortions which are associated with these flows.
Temperature Distribution at the Tool-Chip Interface in Metal Cutting
Authors: Chao B. T. , Trigger K. J.
Published: July 2022

A rapid, iterative method is presented for computing the distribution of temperature at the tool-chip interface. Calculation shows that the maximum temperature occurs at a point near the trailing edge of the contact when chips are produced at conventional feeds and speeds with sintered-carbide tools. The heat-flux distribution at the interface is also obtained. The analysis reveals that, under the usual conditions, heat is being conducted from the tool into the chip over a small region close to the cutting edge. It also has been found that the thermal conductivity of the tool material has only small influence on the mean cutting temperature. Relatively more significant is the effect on the temperature distribution. The role which the interface-temperature distribution plays in the formation of crater wear is pointed out.
Stack Heights Required to Minimize Ground Concentrations
Authors: Hewson E. W.
Published: July 2022

Aerodynamic and meteorological concepts are combined in a procedure for estimating ground concentrations of effluents from stacks with various possible heights and exit gas velocities. The operation of each of the several influences at work is first described. A detailed example is then given of how the most important phases were integrated into a consistent procedure for predicting ground concentrations in answer to a specific design problem. Further improvements and refinements of the method are desirable and are being incorporated in a later study.
Experimental Determination of the Thermal-Entrance Length for the Flow of Water and of Oil in Circular Pipes
Authors: Hartnett J. P.
Published: July 2022

Thermal entrance-length results are presented for the flow of two different fluids, water and oil, in a ¾-in. 4-ft-long tube with a constant heat input per unit length. A hydrodynamic calming section of 97 tube diameters preceded the test section. Pressure-drop measurements in the water tests indicate that the condition of fully established flow at the test-section entrance was closely approximated, if not actually attained. Confidence in the entry-length heat-transfer results is indicated by the agreement of the asymptotic heat-transfer performance of both test fluids with the generally accepted correlation equations. The resulting thermal-entrance lengths were from 10 to 15 tube diameters over the Reynolds modulus range of 104 to 105 and agreed favorably with the analytical results of Deissler and Latzko. When compared at the same Reynolds modulus, the water and oil-entrance lengths were in excellent agreement over the range of Reynolds number common to both fluids (17,000 to 48,000), thereby indicating a negligible influence of the Prandtl modulus on the thermal-entrance length for Prandtl numbers above unity. In the transition region, experimental entry-length values are reported for the flow of oil. As the Reynolds number was increased from 2000 to 10,000, the thermal-entrance length steadily decreased from a large value representative of laminar flow down to a value of approximately 10 diameters.
Heat Transfer and Pressure Drop for Viscous-Turbulent Flow of Oil-Air Mixtures in a Horizontal Pipe
Authors: Johnson H. A.
Published: July 2022

The heat transfer and static pressure drop for two-phase, two-component flow of oil and air were measured for flow in a steam-heated horizontal 15-ft length of ¾-in. extra-heavy copper pipe. This is a second part of a two-phase heat-transfer program for which the first part, on water-air mixtures, was reported in reference (1). Tentative correlations are presented and used in a comparison of the oil-air and water-air results for heat transfer and nonisothermal pressure drop in the same test system.
Accuracy and Results of Steam-Consumption Tests on Medium Steam Turbine-Generator Sets
Authors: Kimball D. E.
Published: July 2022

Precision steam-rate or heat-rate tests on turbine-generator sets insure their owners and builders that the sets equal guaranteed and expected performance. The writer’s company made such tests on 22 medium-sized sets rated 2500 to 18,750 kw between 1946 and 1952. Most were tested at its plant at Lynn, Mass., on facilities for loads of 15,000 kw or less, with steam up 1500 psig and 1000 F. This paper presents the test methods and results, emphasizing an analysis of their accuracy. This analysis shows: (a) 0.5 per cent uncertainty in manufacturing and factory-testing these sets; (b) 0.3 per cent as the day-to-day uncertainty of tests; (c) 0.17 per cent uncertainty to be charged to the instrumentation of factory tests; (d) probably 0.5 per cent poorer performance of tests in the owner’s plants than in factory tests. This analysis confirms our belief of many years that it is proper to accept or reject a turbine-generator set on the basis of precision tests, with no allowance for test error.
Experience in Testing Large Steam Turbine-Generators in Central Stations
Authors: Kratz E. M.
Published: July 2022

Since 1930 the author’s company has participated in the tests of 111 central station steam turbine-generators of 15,000 kw rating or larger. These were all tests in the owners’ power plants, substantially under service conditions. The measurements were made with calibrated test instruments using the careful procedures which experience has proven necessary if reliable data are to be obtained. The purpose of this paper is to make the testing techniques established as a result of this experience available to the power industry and especially to those directly concerned with tests on central station equipment.
Performance of Free-Piston Gas Generators
Authors: McMullen J. J. , Payne W. G.
Published: July 2022

The rapid development now under way of the free-piston gas generator-turbine power plant is outlined. The original Pescara unit in France, and the Cooper-Bessemer and Baldwin-Lima-Hamilton generators being perfected in the United States, are described, and possible applications are mentioned.
A Photographic Study of Events in a 14-In. Two-Cycle Gas-Engine Cylinder
Authors: Boyer R. L. , Craig D. R. , Miller C. D.
Published: July 2022

The more important results are presented from a 2-year research program involving, it is believed, the first high-speed photographic records of events occurring within a very large engine cylinder. This research was performed on a co-operative basis by The Cooper-Bessemer Corporation and Battelle Memorial Institute. Involved in this study was a Cooper-Bessemer GMV engine, a two-cycle, spark-ignited engine of 14-in. bore and 14-in. stroke, which operates on natural gas. This engine is widely used for pumping natural gas through cross-country pipe lines. The photographs were made with the Battelle Isotran camera. Schlieren photographs were taken of combustion, exhaust blowdown, scavenging, gas turbulence, and fuel injection, through large glass windows mounted at various positions in the cylinder head and cylinder wall. All of these phenomena were rendered clearly visible in slow-motion pictures, and exact data were secured for all gas and flame velocities, as well as the crank angles involved in these events. The most important indication from the photographs is the basic nature of flow of scavenging air through the cylinder volume in turbulent jets, which apparently cannot be circumvented.
The Friction Terms in Metal Cutting
Authors: Leone W. C. , Saibel Edward
Published: July 2022

The paper presents the results of an investigation of the friction terms in metal cutting. The so-called “machining constant” is shown to be related directly to the coefficient of internal friction and to vary with the conditions of cutting. The coefficients of external and internal friction appear to be related to the thermal number, and these relationships seem to be quite similar.
The Use of Stator-Blade Control to Obtain Wide Range of Compressor Performance for Wind-Tunnel Application
Authors: McCoy A. W. , Brunner M. J.
Published: July 2022

The conventional axial-flow compressor with a variable-speed drive has a limited operating range which makes it inadequate for many present-day applications. The 16-ft × 16-ft propulsion wind tunnel, now being constructed for the Arnold Engineering Development Center at Tullahoma, Tenn., may be cited as a typical application requiring an unusually wide compressor operating range. Regulation of the performance of an axial-flow compressor by means of controllable stator blades provides an extremely wide range of pressure ratio and volume flow at a constant speed, thus offering a significant improvement over the conventional design. Design considerations and methods of prediction of the performance of axial-flow compressors with stator-blade control are given and discussed. The performance of an experimental compressor designed on this basis is presented. The performance range, extending over a 2:1 ratio of volume flows at efficiencies in excess of 80 per cent, is found to be in agreement with the theoretical predictions.
The Mitigation of Marine Fouling by Anaerobic Treatment
Authors: Duplice H. T. , Alexander R. C.
Published: July 2022

This paper deals with the killing of marine fouling organisms, particularly the bay mussel, in salt cooling-water conduits by anaerobic treatment. In a parallel two-tunnel system it was found possible to make efficient “kills” by removing one of the tunnels from service and preventing the entry of new water into it. The marine life within the tunnel consumed the dissolved oxygen and subsequently died from the resulting anaerobic condition. Removal of the dead shells after treatment was accomplished by velocity cleaning—obviating the necessity of dewatering for mechanical cleaning.
Smokeless Burning of Waste Process Gases
Authors: Reed R. D.
Published: July 2022

Smokeless burning of gases presents serious problems. These are particularly severe in the case of process plants where emergency dumps occur frequently. Such dumps permit no control of any of the factors required for smokeless combustion. This paper describes some of the difficulties and suggests methods for achieving blue-flame burning which is virtually smokeless.
Intermittent Heating of Airfoils for Ice Protection, Utilizing Hot Air
Authors: Hauger H. H.
Published: July 2022

An investigation into the fundamental transient heat-transfer characteristics of the airfoil leading-edge double-skin configuration when heated intermittently by hot air for ice protection was undertaken on an electrical analog computer. This problem is distinctive from other problems usually solved by such a computer in that an electric input circuit had to be designed which would account correctly for the heat balance as the air passes chordwise through the double-skin passages. Also, a combination of electrical networks was devised which would take into account satisfactorily the thermal resistance and capacitance of the growing layers of ice. This research reveals the effect on the de-icing ability of the double-skin design of variables deemed to be important in such a study. The feasibility of such an ice protection system is attested, and the compromises inherent in the cyclic use of hot air are determined.
A New Type of Radiant Tubular Heater
Authors: Kreipe T. F.
Published: July 2022

The advantages of applying direct radiant heat to both sides of heating coils in tubular furnaces, as compared to the more customary direct application of radiant heat from one side only, is discussed. The operation, construction, and application of a novel radiant-type burner is described which embodies many desirable features. Use of the burner in tubular heaters is discussed and operating data are presented.
Mechanical Aspect of Seizing in Metal Wear
Authors: Czyzewski Harry
Published: July 2022

Alloys of the class called “self-lubricated” alloys have a resistance to “accelerated mechanical abrasion” which it has not been possible to duplicate by external lubrication. Alloys in this class include gray cast iron (graphite lubricant), oil-impregnated powder-metal compositions (oil lubricant) and leaded copper-base and iron-base alloys (lead lubricant). It is the purpose of this paper to present the mechanical aspect of seizing in metal wear which accounts in a qualitative manner for the observed phenomena in accelerated mechanical abrasion. The mechanical analysis also explains the failure of externally lubricated alloys to equal the performance of self-lubricated alloys.
Rapid Measurements of Thermal Diffusivity
Authors: McIntosh G. E. , Hamilton D. C. , Sibbitt W. L.
Published: July 2022

An apparatus and a technique were developed for determining the thermal diffusivity of metals by a periodic heat-flow method. Measurements with a probable error of ± 6.8 per cent were made on specimens of Armco iron, titanium, zirconium, and Haynes Stellite 25 at temperatures of 456, 564, and 672 R.