bluuebunny/crossref_metadata_2025 huggingface dataset:
Creating relationship‐based practice in youth employment services—Converting policy intentions to practical program design
Authors: Meltzer Ariella , Ramia Ioana , Moffatt Jennifer , Powell Abigail
Published: July 2022

Relationship‐based practice refers to approaches within human services which centralise inter‐personal relationships—either those between clients and workers or between clients and their own network—as a way to achieve positive service outcomes. Relationship‐based practice is increasingly recognised as a critical component in many areas of human services, particularly youth services. Despite increasing policy intentions for programs to adopt a relationship‐based approach, it is not always clear how services can implement this in practice. While relationship‐based skill training can be offered to individual workers, a question remains as to what can be done at an organisational and policy level to cultivate relationship‐based practice. Within this context, this paper explores how programs can be designed to foster relationship‐based practice. The paper draws on the evaluation of an intensive and tailored service for addressing long‐term youth unemployment in Australia: the your job your way pilot program run by yourtown. A key success of the program was strong relationship‐based practice, and this paper explores five features of the program's design that enabled this: (1) small caseloads, (2) intensive support, (3) staff with complementary skills and a professional and ‘youth friendly’ demeanour, (4) staff discretion about some aspects of program implementation, and (5) support delivered through social and group activities. The paper draws implications for how service provider organisations and governments can cultivate relationship‐based practice in human services.
Chromosome painting reveals inter‐chromosomal rearrangements and evolution of subgenome D of wheat
Authors: Shi Peiyao , Sun Haojie , Liu Guanqing , Zhang Xu , Zhou Jiawen , Song Rongrong , Xiao Jin , Yuan Chunxia , Sun Li , Wang Zongkuan , Lou Qunfeng , Jiang Jiming , Wang Xiue , Wang Haiyan
Published: July 2022

Aegilops species represent the most important gene pool for breeding bread wheat (Triticum aestivum). Thus, understanding the genome evolution, including chromosomal structural rearrangements and syntenic relationships among Aegilops species or between Aegilops and wheat, is important for both basic genome research and practical breeding applications. In the present study, we attempted to develop subgenome D‐specific fluorescence in situ hybridization (FISH) probes by selecting D‐specific oligonucleotides based on the reference genome of Chinese Spring. The oligo‐based chromosome painting probes consisted of approximately 26 000 oligos per chromosome and their specificity was confirmed in both diploid and polyploid species containing the D subgenome. Two previously reported translocations involving two D chromosomes have been confirmed in wheat varieties and their derived lines. We demonstrate that the oligo painting probes can be used not only to identify the translocations involving D subgenome chromosomes, but also to determine the precise positions of chromosomal breakpoints. Chromosome painting of 56 accessions of Ae. tauschii from different origins led us to identify two novel translocations: a reciprocal 3D‐7D translocation in two accessions and a complex 4D‐5D‐7D translocation in one accession. Painting probes were also used to analyze chromosomes from more diverse Aegilops species. These probes produced FISH signals in four different genomes. Chromosome rearrangements were identified in Aegilops umbellulata, Aegilops markgrafii, and Aegilops uniaristata, thus providing syntenic information that will be valuable for the application of these wild species in wheat breeding.
Research strategies for single‐cell transcriptome analysis in plant leaves
Authors: Liu Zhixin , Yu Xiaole , Qin Aizhi , Zhao Zihao , Liu Yumeng , Sun Susu , Liu Hao , Guo Chenxi , Wu Rui , Yang Jincheng , Hu Mengke , Bawa George , Sun Xuwu
Published: July 2022

The recent and continuous improvement in single‐cell RNA sequencing (scRNA‐seq) technology has led to its emergence as an efficient experimental approach in plant research. However, compared with single‐cell research in animals and humans, the application of scRNA‐seq in plant research is limited by several challenges, including cell separation, cell type annotation, cellular function analysis, and cell–cell communication networks. In addition, the unavailability of corresponding reliable and stable analysis methods and standards has resulted in the relative decentralization of plant single‐cell research. Considering these shortcomings, this review summarizes the research progress in plant leaf using scRNA‐seq. In addition, it describes the corresponding feasible analytical methods and associated difficulties and problems encountered in the current research. In the end, we provide a speculative overview of the development of plant single‐cell transcriptome research in the future.
Logistics of managing a trauma whole blood inventory in a civilian level 1 trauma center
Authors: Phan‐Tang Michelle , Lee Christine M. , Fang Amy , Rioveros Jowin , Siletz Anaar E. , Cryer Henry , McGonigle Andrea M. , Ziman Alyssa , Ward Dawn C.
Published: July 2022

Background

Institutional data on initiating and maintaining a low‐titer O positive whole blood (LTOWB) inventory for the civilian trauma sector may help other institutions start a LTOWB program. This study from a level 1 trauma center with a hospital‐based donor center highlights challenges faced during the collection, maintenance, and utilization of LTOWB.

Study Design and Methods

Male O positive donors with low (≤1:100) anti‐A and anti‐B antibody titers were recruited for LTOWB collection. The daily inventory goal of 4 LTOWB units was kept in the emergency department refrigerator and transfused to adult male trauma patients. Unused units older than 10 days were reprocessed into packed red blood cells.

Results

Of 900 donors screened, 61% qualified and 52% of eligible donors provided a collective total of 505 LTOWB units over 2.5 years. The number of collected units directly correlated with the availability of inventory; 42% of the units were transfused, 54% were reprocessed, and 4% were discarded. The inventory goal was maintained for 56% of the year 2018 and 83% of the year 2019. Over these 2 years, 52% of patients had their transfusion needs fully met, 41% had their needs partially met, and 6.5% did not have their needs met.

Discussion

Initial challenges to LTOWB implementation were inventory shortages, low utilization rates, and failure to meet clinical demand. Proposed solutions include allowing for a higher yet safe titer, extending shelf life, expanding the donor pool, identifying barriers to utilization, and permitting use in female trauma patients beyond childbearing age.
Distribution of Mechanical and Thermal Stresses in Multilayer Cylinders
Authors: Strub R. A.
Published: July 2022

Relations for the optimum proportions of multilayer vessels and the computation of stresses are derived. They are based on the energy of distortion-strength theory which is discussed and illustrated by a photographed model. It is shown that the stress distribution in fully or partially plastic cylinders can be obtained as the limit case of a multilayer vessel with an infinite number of layers of constant or variable yield point. Relations are proposed for the determination of the plastic strains. The problem of thermal stresses is discussed and a graphical method for the rapid computation of transient thermal stresses is explained.
Cyclone Dust Collectors for Boilers
Authors: ter Linden A. J.
Published: July 2022

A laboratory analysis is given of various cyclone dust collectors according to requirements prevailing in Holland. The author describes the experimental studies, theoretical considerations, and efficiencies of different types. Suggestions are given of cyclones suitable for grate-fired and pulverized-fuel-fired boilers in various locations.
Some Observations on Chip Curl in the Metal-Cutting Process Under Orthogonal Cutting Conditions
Authors: Hahn R. S.
Published: July 2022

An experimental study of the phenomenon of chip curl is made. It was found that transient behavior of the chip curvature was independent of cutting speed. Evidence is offered to show that chip curl originates in the shear region. Numerous hypotheses were made to explain the curl and were examined. It appears that the chip curl is associated with thermal effects in the shear region.
Effect of Rotary Regenerator Performance on Gas-Turbine-Plant Performance
Authors: Harper D. B. , Rohsenow W. M.
Published: July 2022

A comparison of typical solutions for determining rotary-regenerator performance is presented. Curves showing the effect of leakage on regenerator effectiveness and plant performance are presented. Specific examples are investigated showing the effect on plant performance of variations in regenerator rotational speed, matrix length, and mass velocity of the gas passing through the matrix.
Theoretical Consideration of Retarded Control
Authors: Cohen G. H. , Coon G. A.
Published: July 2022

This paper is concerned with a theoretical study of the control of a single-capacity process with dead-period lag. Characteristic equations corresponding to the application of proportional, proportional-plus-derivative, proportional-plus-reset, and proportional-plus-reset-plus-derivative responses are used to graph the controller parameters necessary to obtain a desired degree of stability. The degree of stability is taken to be associated with the amplitude ratio of the lowest-frequency harmonic mode. Effects of the various controller parameters are shown and a method is suggested to determine the adjustable parameters for a desired degree of stability.
Heat Transfer to Molten Lead-Bismuth Eutectic in Turbulent Pipe Flow
Authors: Johnson H. A. , Hartnett J. P. , Clabaugh W. J.
Published: July 2022

Experimental heat-transfer results for molten lead-bismuth eutectic are presented for turbulent flow in a ¾-in. 18-gage mild-steel tube with constant heat flux. Validity of the measurement technique is established indirectly by identical tests with water which agree with the predicted heat-transfer performance for that fluid. Results for lead bismuth are correlated for the Peclet modulus range of 200 to 5000 over a Prandtl modulus range of 0.020 to 0.046 and Reynolds-number range of 7500 to 170,000. The resulting Nusselt moduli are 25 to 35 per cent lower than the prediction of Lyon-Martinelli momentum theory for turbulent flow. Local heat-transfer coefficients at the start of the heated section reveal that the thermal entrance length is approximately 30 pipe diameters.
Oil Whip of Flexible Rotors
Authors: Hagg A. C. , Warner P. C.
Published: July 2022

Bearings serve to link machine parts with relative motion. Sometimes this primary role is exceeded with oil-film bearings, and the self-excited-vibration oil whip occurs. A stability criterion which includes the effect of rotor flexibility has been devised through an electric-analog study, and interpretation on the basis of bearing properties is in substantial agreement with test results, and experience with actual machines. In particular it is shown that rotor flexibility reduces the region of stable operation; however, the final question of stability depends on all system elements involved in the motion.
The Size Effect in Metal Cutting
Authors: Backer W. R. , Marshall E. R. , Shaw M. C.
Published: July 2022

A cutting process involving the formation of very small chips at high cutting speeds (micromilling) is investigated, and the results are applied to a study of the grinding operation. The shear energy involved in grinding is compared with that in turning, micromilling, and the tensile test, and a significant increase in shear energy is observed with decrease in specimen (chip) size. The shear stress involved in grinding metals under mild conditions is found to correspond to the theoretical strength which is about 1.8 × 106 psi for steel. The grit depth of cut is shown to be a more important variable in the interpretation of grinding data than the more conventional wheel depth of cut.
Multistage Radial Turbines
Authors: Martinuzzi P. F.
Published: July 2022

There are many applications of radial-flow turbomachines, but this paper deals particularly with radial turbines for gas-turbine use. The possibility of building a multistage inflow turbine of a type in which all the stages are carried on a single rotor disk is examined.
Determination of Principal Plastic Strains
Authors: Cooper W. E.
Published: July 2022

Techniques are presented whereby the grid method of plastic-strain determination may be extended to include the determination of strain at a point, rather than over a finite gage length, and the determination of the principal strain, magnitude, and direction, when these directions are not necessarily in alignment with the original grid. Measurement may be made in terms of either the tensor or logarithmic definitions of finite strain.
Orifice and Flow Coefficients in Pulsating Flow
Authors: Hall N. A.
Published: July 2022

The flow equations pertaining to the behavior of a fluid passing through an orifice are set forth so as to relate the flow coefficient to the orifice configuration and to flow losses. The general nature of the flow coefficient is developed both for the case of instantaneous flow and pressure differences and for mean flow and pressure difference.
Thermophysical Aspects of Metal Cutting
Authors: Chao B. T. , Trigger K. J. , Zylstra L. B.
Published: July 2022

Some basic issues in the theory of metal cutting are analyzed in the earlier part of this paper. Several controversial subjects are clarified by the experimental results presented. The remainder of the paper describes a further attempt to ascertain the effect of cutting speed and feed on the mechanism of chip formation in high-speed machining operations. A differential equation of the temperature field in the chip as well as that in the workpiece has been set up, and the nature of the solution studied. It has been found that the temperature distribution both in the work material and in the deformed chip in the immediate vicinity of the tool-chip interface depends upon a dimensionless number which is expressible as the ratio of the product of the cutting speed and feed to the thermal diffusivity of the metal cut. This ratio is called the thermal number, and its significance in metal cutting is illustrated and the limitations discussed.
The Rotary Cutting Tool
Authors: Shaw M. C. , Smith P. A. , Cook N. H.
Published: July 2022

A novel lathe-type cutting tool in the form of a disk that may be rotated about its central axis is described and analyzed. Such a rotary tool is found to correspond to an equivalent oblique tool having an angle of inclination whose tangent is equal to the ratio of the tool and work-surface velocities. In addition to the inherent feature of the oblique tool of providing a greater effective rake angle without a corresponding decrease in the actual included angle of the tool, the rotary tool (1) provides a rest period for the cutting edge, thus enabling the edge to be cooled and the adsorbed film on the tool surface to be replenished between cuts; (2) enables the relative chip velocity to be increased to provide a lower coefficient of friction without necessitating a corresponding increase in the rate of metal removal. A rotary tool of 10-deg rake angle is capable of reducing total power required to make a given cut by about 30 per cent and at the same time to operate with a temperature about 400 F lower than that for the equivalent stationary tool. Representative test data for both rotary and stationary tools are analyzed and discussed. The shear stress on the shear plane is found to decrease with increased shear strain in the case of either a rotary tool or an oblique tool. This anomalous result is explained in terms of a size effect associated with the change in thickness of the shear plane that accompanies a change in the angle of inclination.
Photographic Analysis of Sprays
Authors: York J. L. , Stubbs H. E.
Published: July 2022

This paper describes an experimental method for determining the size distribution and velocities of drops in a spray. Photographs are taken of a small known volume of the spray, and the images of the drops are counted and measured to give the size distribution. Velocities are determined by taking two exposures on the same film and measuring the displacement of the drops in the interval between exposures. Since a photographic method does not require any objects in the spray, the results are free of bias from disturbances of the flow pattern. The technique is applicable to sprays in which the diameters of drops range from 15 to 500 microns and gives results which differ by less than 20 per cent from the metered values of total flow rate.
Convective Heat-Transfer and Flow-Friction Behavior of Small Cylindrical Tubes—Circular and Rectangular Cross Sections
Authors: Kays W. M. , London A. L.
Published: July 2022

Recent heat-transfer and flow-friction test data (1) for gas flow in small circular and rectangular cylindrical tubes, in the laminar, transition, and low-Reynolds-number turbulent-flow regimes, are examined and compared with earlier results. For circular tubes in laminar flow, the heat-transfer results substantiate very well analytical predictions as summarized by Norris and Streid (2). In turbulent flow, circular-tube heat transfer is correlated by an empirical nondimensional equation of the same form, but with a somewhat lower coefficient than has been commonly employed in the past. The difference is attributable in part to the use of more recent data on air properties in the reduction of test results to a nondimensional form. The transition region for circular tubes is found to extend from about NR ~ 2000 to NR ~ 10,000, and heat-exchanger design in this “dip” region is discussed. Laminar-flow circular-tube friction factors show an entrance length effect, similar to that found for heat transfer, and it is demonstrated that the analysis of Langhaar (3) for flow in a single tube can be employed to predict friction factors with acceptable accuracy for flow through a tube bundle even with the sudden change of flow area at the contracted tube-entrance section. For small circular tubes, as a result of this analysis, recommended design correlations in graphical form are given for the NR range 500 to 50,000.

The turbulent-flow heat-transfer and friction performance of rectangular tubes is in close agreement with the characteristics for circular tubes. However, there is a marked difference in the laminar and transition behavior, where the aspect ratio of the rectangular cross-section is demonstrated to have an important influence. It is concluded that considerable additional work, both analytical and experimental, is needed to ascertain laminar and transition flow-friction and heat-transfer characteristics in rectangular tubes.
A General Theory of Three-Dimensional Flow in Subsonic and Supersonic Turbomachines of Axial, Radial, and Mixed-Flow Types
Authors: Wu Chung-Hua
Published: July 2022

A general theory of steady three-dimensional flow of nonviscous fluid in subsonic and supersonic turbomachines having arbitrary hub and casing shapes and a finite number of thick blades is presented. The solution of the three-dimensional direct and inverse problem is obtained by investigating an appropriate combination of flows on relative stream surfaces whose intersection with a z-plane either upstream of or somewhere inside the blade row forms a circular arc or a radial line. The equations obtained to describe the fluid flow on these stream surfaces show clearly the approximations involved in ordinary two-dimensional treatments, assuming flow surfaces of revolution or an infinite number of blades. They also lead to a correct solution of the three-dimensional flow in a mathematically two-dimensional manner. A general procedure to solve the direct or inverse three-dimensional problem is described for both subsonic and supersonic flow. The theory is applicable to both irrotational and rotational absolute flow at the inlet of the blade row and at both design and off-design operations.
Properties of Thin-Walled Curved Tubes of Short-Bend Radius
Authors: Pardue T. E. , Vigness Irwin
Published: July 2022

Flexibility factors and stress-intensification factors have been measured for a group of thin-walled tube bends having a ratio of pipe radius to bend radius of 1/3. A theoretical analysis, which eliminates some of the simplifying assumptions of previous theoretical analyses, has been included for comparison with the experimental data. Reasonably good agreement between theory and experiment has been found for U-bends and 90-deg bends with straight sections of piping attached to the ends of the bend. Rigid constraints attached to the ends of the bend have been found to affect the measured quantities greatly. The effect of the end conditions has been studied experimentally but not theoretically.
Flow of a Flashing Mixture of Water and Steam Through Pipes and Valves
Authors: Allen W. F.
Published: July 2022

A simple method is presented of designing piping and valves, particularly heater drain piping, to carry a flashing mixture of water and steam. Rational design formulas are derived from the energy, continuity, and dynamic equations on the basis of an assumed uniform mixture at any point in the path of flow. Earlier papers have predicted and verified experimentally the existence of a critical pressure, under certain conditions at the end of a pipe carrying a flashing mixture. Results calculated from the derived formulas compare favorably with these published test data. It is noted that if the initial assumption of a uniform mixture is not fulfilled, the limitations imposed on the piping are less severe than for the uniform-mixture case, as the capacity of both valves and pipes will be greater than predicted by formulas. A scheme is suggested for eliminating flashing completely in heater drain systems employing drain coolers.
Effect of Internal Pressure on Stresses and Strains in Bolted-Flanged Connections
Authors: Wesstrom D. B. , Bergh S. E.
Published: July 2022

It is shown that the elastic deformations, and therefore the forces and moments, in a bolted-flanged connection vary with the magnitude of the internal fluid pressure, and that the actual conditions existing in a bolted joint will be considerably different from those assumed when using the concept of design upon which the rules of the ASME Unfired Pressure Vessel Code must be based. For certain critical ranges of joint diameter, pressure, and stress, it becomes important to analyze the design for the actual conditions that will be obtained (a) in assembling the joint, (b) at test pressure, and (c) in service. Formulas are derived for calculating these conditions and the results are summarized in the form of a design procedure.
Discharge Coefficients of Small-Diameter Orifices and Flow Nozzles
Authors: Grace H. P. , Lapple C. E.
Published: July 2022

Discharge coefficients were determined in a standard 1-in. pipe for thick-plate and knife-edge orifices of 1/32-in. to 3/4-in. diam, and for critical (sonic) flow nozzles of 1/32-in. to 1/4-in. diam. With properly constructed knife-edge orifices the discharge coefficients were established within ±0.5 per cent for all sizes, but, with small orifices of 1/4 to 1-hole-diam thickness, the discharge coefficients were not reproducible. Thick-plate orifices (1-hole-diam thick) were found to be as good or better than nozzles in constancy of discharge coefficients when used under critical-flow conditions.
Creep Properties of Lucite and Plexiglas for Tension, Compression, Bending, and Torsion
Authors: Marin Joseph , Pao Yoh-Han , Cuff George
Published: July 2022

In this investigation, creep-time relations in tension, compression, bending, and torsion were obtained for lucite and plexiglas. For each type of stress the influence of the stress and time on the creep deformations and creep rates were determined. Various interpretations of the test data were made. It was found that there was a linear relation between the minimum constant creep rates and the stress when represented on a log-log plot. The creep deformations in tension and compression were expressed in terms of the stress and the time by an equation which considered the initial creep strain. A theory was developed for predicting the creep deflection and creep rate in bending, using the creep constants in tension and compression. Good agreement was found between the experimental and theoretical results.
Cutting Temperatures and Metal-Cutting Phenomena
Authors: Chao B. T. , Trigger K. J.
Published: July 2022

This paper considers some important findings which resulted from an investigation on the mechanism of heat generation during metal-cutting operations. It has been found that many changes during the cutting of metals are due to the change in tool-chip interface temperature through its influence on tool-chip friction. The paper is divided into two parts, the first of which pertains to the cutting forces and cutting temperatures observed during conventional turning and orthogonal cutting under otherwise identical conditions. The higher heat-dissipating capacity of the tool in orthogonal cutting operations was found to be fundamentally responsible for the observed differences. In the second part of the paper, the role of tool-chip contact area on interface temperatures is further investigated. This study has been of value in the interpretation of tool-chip interface temperature data and other phenomena heretofore inexplicable.
Heat Transfer to a Fluid Flowing Turbulently in a Smooth Pipe With Walls at Constant Temperature
Authors: Seban R. A. , Shimazaki T. T.
Published: July 2022

The case of heat transfer to an incompressible fluid of constant properties flowing turbulently within a pipe having constant wall temperature has been investigated analytically. Heat-transfer coefficients have been evaluated and compared to the coefficients obtained by Martinelli (1) for the same flow conditions in a pipe having a linear variation of wall temperature obtained from a constant heat-transfer rate along the pipe length. At low Prandtl numbers, such as obtained with molten metals, the ratio between the coefficients for these two cases may become as low as 0.73, with the coefficient for the constant-wall-temperature case being the smaller of the two. A simple equation of the Lyon type is indicated for the correlation of the present results.
A Standard Laboratory Corrosion Test for Metals in Phosphoric-Acid Service
Authors: Ebling H. F. , Scheil M. A.
Published: July 2022

It is the purpose of this paper to show the need of a standard test for materials to be used in phosphoric-acid service. We propose and use a standard laboratory phosphoric-acid test to evaluate materials for phosphoric-acid service. This test is explored presenting some possible difficulties and their corrections. The relation between the laboratory test and our field experience is presented and illustrated. A table of laboratory corrosion test results is presented as a guide in selecting metals for phosphoric-acid service.
Selection, Operation, and Maintenance of Industrial Cooling Equipment: Cooling Towers and Air-Cooled Exchangers
Authors: Degler H. E.
Published: July 2022

To avoid water shortages, conservation and re-use of water have become a necessity in many areas. Water can be purified, cooled, and re-used. Large industrial water users are power plants, manufacturers of paper, petroleum products, rayon, linens, textiles, lactose, sugar, explosives, hydrogen, rubber, steel, and so forth. Requirements are frequently in excess of 300 lb of water per lb of finished product. Water usage has doubled in the past decade—hence selection of cooling equipment becomes more important as power demands increase, industries expand, and new processes are perfected. Mechanical-draft cooling towers can cool water evaporatively to a temperature approaching the wet-bulb temperature of the ambient air. This evaporative method requires less than 1 per cent evaporation of the water circulated to dispose of the heat load economically. Air-cooled finned-tube exchangers are having increased acceptance and usage for “high-level heat removal” (for example, above 130 F referred to 100 F dry-bulb air), where water is scarce, expensive, and/or badly polluted; small space requirements and easy control are other features. The performance and life of any piece of cooling equipment is directly dependent upon its inherent qualities, type of service, severity of operation, general care and maintenance, and climatic environment.
The Fatigue Strength of Threaded Connections
Authors: Thurston R. C. A.
Published: July 2022

Published information on the strength of threaded connections subjected to dynamic loading has been surveyed and summarized, with particular reference to high-duty applications. After a consideration of the load distribution and the concentration of stress at the thread roots, the subject is discussed from the following viewpoints: Effect of thread form; effect of method of manufacture; effect of degree of tightness; methods for improving performance; special modifications in design. In general, the basic principles to be followed in the design of high-strength bolt and stud assemblies are outlined, the reasons underlying them explained, and evidence in their support given when possible.
The Forces and Moments in the Leg During Level Walking
Authors: Bresler B. , Frankel J. P.
Published: July 2022

The mechanism of normal level walking is presented in this paper in terms of the displacements of and the force systems at the leg joints. The data on four normal subjects were obtained from simultaneous recording of the positions of the leg in space and the floor reactions during level walking. The mass moments of inertia of the lower extremity were determined experimentally and the effects of gravity and inertia were included in the analysis. The forces and moments are presented in terms of the space components referred to a system of horizontal and vertical orthogonal axes.
Forming of a Plastic Sheet Between Fixed Cylindrical Guides With Coulomb Friction
Authors: Ansoff H. I.
Published: July 2022

The purpose of this investigation was to obtain a rigorous analysis of the drawing of a plastic sheet between two fixed cylindrical surfaces. A number of solutions have recently been given (1, 2, 3, 4, 5) in which the following fundamental assumptions are used: (a) The material between the cylinders is in a state of plane plastic flow and behaves according to the Saint Venant-Mises theory; (b) the normal stress in the direction of drawing σx and the normal stress at the boundary σn are the principal stresses, (c) the horizontal stress σx is constant over each cross section. In the present treatment only assumption (a) is retained. Shevchenko (4) has recently solved this problem assuming that the shearing stress at the walls is proportional to the relative velocity between the wall and the plastic material.
Bending of an Ideal Plastic Metal
Authors: Lubahn J. D. , Sachs G.
Published: July 2022

The stresses and strains in plastically bent parts have been analyzed for the two limiting conditions of (a) a very wide plate (plane strain), and (b) a very narrow bar (plane stress). The complete solution is presented for a hypothetical metal with no strain-hardening, and the method is described for treating any actual metal. The solution was obtained by a method of successive approximations, each approximation employing various graphical processes. The gradual change in cross-sectional contour with progressive bending was obtained by considering small successive intervals of increasing curvature. The final solution shows the movement of the neutral axis toward the compression surface, the decrease in the radial dimension of the part, and the gradual divergence between the tangential strains at the inside and outside surfaces. The solutions for plane stress and plane strain were nearly identical as regards the tangential strains and the changes in the radial dimension. Experimental measurements of surface strains and cross-sectional contour of bends conformed well with the results of the calculations.
Hide-Out of Sodium Phosphate in High-Pressure Boilers
Authors: Straub F. G.
Published: July 2022

A study has been made to explain a type of hide-out of sodium phosphate in steam boilers operating at about 1700 psi. This has shown that an insoluble form of a sodium phosphate is stable at temperatures above 620 F. This type of phosphate is scale-forming and is resistant to heat transfer. This sodium phosphate does not have the properties corresponding to those of the sodium phosphates normally encountered in steam-boiler water. Analyses by chemical means, x rays, and petrographic all indicate that this is a different form of sodium phosphate. Tests indicate that no insoluble potassium phosphate is formed and, if suitable potassium-to-sodium ratio is maintained, this insoluble salt will not form.
Some New Values of the Second Enthalpy Coefficient for Dry Air
Authors: Andersen J. R.
Published: July 2022

Measurements of the second enthalpy coefficient for dry CO2-free air are reported for three temperatures: 0 C, 10 C, and 30 C. These values, which are in excellent agreement with the best data on air in the literature, were formulated, together with the data of Eucken, Clusius, and Berger by the equation β=-0.05442G(0.01244T),ft3/lb The second virial coefficient was then calculated by means of the equation B=0.05442F(0.01244T)-2.33×10-5T,ft3/lb where the value of the constant of integration was adjusted to give the best fit with the Holborn and Schultze compressibility data. These equations represent adequately all reliable data on air in the temperature range −80 C to 200 C. The functions F and G are the well-known Lennard-Jones functions, abridged tables of which are given in the Appendix.
Heat Transfer to a Fluid Flowing Turbulently Between Parallel Walls With Asymmetric Wall Temperatures
Authors: Seban R. A.
Published: July 2022

The case of heat transfer to a fluid of constant properties flowing turbulently between parallel walls having arbitrary but uniform temperatures is considered on an analytical basis, which is an extension of the work of Martinelli and of Harrison and Menke. Therefore, only conditions for a flow fully developed from the hydrodynamic and thermal standpoint are considered. It is shown that the existence of solutions for the case of one adiabatic wall enables the specification of the temperature distribution and heat-transfer coefficients for cases in which the walls have any uniform temperature values. The effect of inequality in the wall temperatures is shown to be small for Prandtl numbers greater than unity but significant for fluids of low Prandtl number, such as molten metals. To facilitate its use in the present applications, the existing solution for one adiabatic wall is extended.
The Flow Through Centrifugal Compressors and Pumps
Authors: Sheets H. E.
Published: July 2022

The flow through centrifugal compressors and pumps is a three-dimensional flow problem and is of such a complex nature that an exact solution is not obtainable. The literature (1, 2) shows the differential equations which the flow through an impeller must follow. An approximate solution to these equations is found by means of certain assumptions which are possible for impellers within a limited range of specific speeds. The solution gives the approximate velocity and pressure distribution in the impeller passages. The knowledge of the velocity distribution is used to analyze the phenomena of pulsation and blade stalling. The method has also been used in mixed-flow compressors and radial- and mixed-flow turbines. The application of this method for two impellers and test data are presented.
Film Thickness Between Gear Teeth: A Graphical Solution of Karlson’s Problem
Authors: Hersey M. D. , Lowdenslager D. B.
Published: July 2022

This investigation completes a solution, undertaken by K. G. Karlson in his little-known Swedish paper of 1926, for the oil-film thickness between gear teeth. Karlson’s problem is characterized by the use of a parabolic curve for the viscosity-pressure relation. The numerical results here obtained are comparable with those previously published by Gatcombe, who used a more conventional viscosity-pressure formula. It is hoped that the present analysis will help to clarify the assumptions and calculations required in the hydrodynamic theory of gear-tooth lubrication. As an aid to its practical application, the relative film thicknesses found for geometrically similar pairs of gears are here shown by a chart constructed in terms of the appropriate dimensionless variables, and extending from zero to 10 microinches per in. of pitch diameter of the pinion. The limiting case of a lubricant whose viscosity is unaffected by pressure, for which an analytical solution had been given by Karlson, is represented by a straight line on this chart.
Effect of Horizontal Vibrations and Particle Size on the Packing Density of Multi-Sized Sphere Mixtures: Discrete Element Method Simulation
Authors: Salamat Azamat , Golman Boris , Spitas Christos
Published: July 2022

Particle packing densification due to vibrations is a common process that occurs in many industrial applications and is beneficial for achieving better mechanical properties in powder metallurgy. However, most of the research up to this point was focused on vibration compaction of uniform-sized or binary particle mixtures, while most actual commercial powders consist of particles of variable sizes. In this work, the packing of multi-sized sphere mixtures under horizontal vibrations is simulated with the help of the discrete element method (DEM). The variations of total and local packing density with vibrations and particle size were investigated. The simulation results suggest that there are optimal values for the two vibration parameters at which the closest packing is obtained. Further increase in the particle size decreases the density and slightly shifts these peaks to the lower values of vibrations. Local density values are quite uniform at the optimal vibration parameters, but the deviations become higher when frequency or amplitude is too low or high. With an increase in particle size, these trends become less profound and more deviated. The investigations of effects of size can help in predicting optimal parameters and density values for experimental studies. These developments are similar to those for uniform and binary particle assemblies and correlate with experimental and numerical studies from the literature. The results can be helpful in carefully choosing the particle mixture properties and vibration conditions for actual manufacturing.
Influence of Tool Thread Pitch During Friction Stir Welding of High-Density Polyethylene Plate
Authors: Wilkins Lucas T. , Strauss Alvin M.
Published: July 2022

This study utilizes a face-centered central composite response surface design of experiments to determine the effects of thread pitch when friction stir welding high-density polyethylene. The tool pin thread pitch, along with rotation and traversing speed, was varied so that models of the maximum tensile strength, tool temperature, and tool forces could be analyzed. Coarser thread pitches facilitated higher tensile strength than finer threads due to greater material velocity and overlap between the stir zone and base material. In the tested range, the thread pitch provided a 6% linear contribution to ultimate tensile strength, whereas welds with coarse threads had on average a 2.83 MPa increase in tensile strength over the fine thread tool. The greater circumferential pin surface area of fine threads caused a greater increase in tool temperature, though this did not correlate to stronger welds. Ultimately, the most interdiffusion across the polymer joint occurred with the coarser thread pitch and slow traverse speed due to prolonged joint exposure to the molten polymer weld pool.
An Adaptive Two-Stage Kriging-Based Infilling Strategy for Efficient Multi-Objective Global Optimization
Authors: Liu Yin , Wang Shuo , Li Kunpeng , Sun Wei , Song Xueguan
Published: July 2022

Most practical multi-objective optimization problems are often characterized by two or more expensive and conflicting objectives, which require time-consuming simulations. Commonly used algorithms construct a surrogate model of each objective function from a few high-fidelity solutions. In order to further decrease the computational burden, adaptive infilling strategies for multi-objective problems are developed to guide the next infilling design for expensive evaluation and update the surrogate model as well as the Pareto front in an iterative manner. In this paper, a multi-objective infilling strategy integrating the Kriging model with a two-stage infilling framework is proposed, termed as ATKIS. This method allows exploitation and exploration alternately to pinpoint the infilling solution for improving the Pareto set and avoiding local over-exploitation simultaneously. At the local exploitation stage, Kriging-based prediction and uncertainty estimation are combined with Non-dominant Ranking and Minimum Relative Distance theories for determining a new design solution, which has maximum improvement relative to the current Pareto set. At the global exploration stage, Voronoi tessellation theory is employed to search for the sparsest position in the design space for a new evaluation. The proposed method is compared with five recent infilling strategies to investigate the performance of infilling ability using several numerical benchmarks. The experimental results show that the proposed method outperforms the other three strategies in improving both effectiveness and robustness using the improvement of hypervolume as the evaluating indicator. In addition, a lightweight optimization design of hoist sheaves shows that the proposed method can deal with real engineering problems, while significantly reducing the computational time and the number of expensive simulations of samples.
Revision of the African chigger genus Austracarus (Acariformes: Trombiculidae: Leeuwenhoekiinae)
Authors: Stekolnikov Alexandr A
Published: July 2022

The African genus Austracarus Lawrence, 1949 was revised based on type specimens and literature data. Two species were transferred to this genus from Acomatacarus Ewing, 1942—A. gateri (Radford, 1942) and A. theileri Radford, 1947. Re-descriptions of these species based on their holotypes and one topotypic specimen were prepared. Two species were re-described based on their paratypes—Austracarus procaviae Lawrence, 1949 and A. dendrohyracis (Vercammen-Grandjean, 1957). The monotypic genus Austrombicula Lawrence, 1949 was synonymized with Austracarus. An updated diagnosis and a key to species of Austracarus are provided.
Evidence for a neuromuscular circuit involving hypothalamic interleukin-6 in the control of skeletal muscle metabolism
Authors: Katashima Carlos Kiyoshi , de Oliveira Micheletti Thayana , Braga Renata Rosseto , Gaspar Rodrigo Stellzer , Goeminne Ludger J. E. , Moura-Assis Alexandre , Crisol Barbara Moreira , Brícola Rafael S. , Silva Vagner Ramon R. , de Oliveira Ramos Camila , da Rocha Alisson L. , Tavares Mariana Rosolen , Simabuco Fernando Moreira , Matheus Valquiria Aparecida , Buscaratti Lucas , Marques-Souza Henrique , Pazos Patricia , Gonzalez-Touceda David , Tovar Sulay , del Carmen García María , Neto Jose Cesar Rosa , Curi Rui , Hirabara Sandro Massao , Brum Patrícia Chakur , Prada Patrícia Oliveira , de Moura Leandro P. , Pauli José Rodrigo , da Silva Adelino S. R. , Cintra Dennys Esper , Velloso Licio A. , Ropelle Eduardo Rochete
Published: July 2022

Hypothalamic interleukin-6 (IL6) exerts a broad metabolic control. Here, we demonstrated that IL6 activates the ERK1/2 pathway in the ventromedial hypothalamus (VMH), stimulating AMPK/ACC signaling and fatty acid oxidation in mouse skeletal muscle. Bioinformatics analysis revealed that the hypothalamic IL6/ERK1/2 axis is closely associated with fatty acid oxidation– and mitochondrial-related genes in the skeletal muscle of isogenic BXD mouse strains and humans. We showed that the hypothalamic IL6/ERK1/2 pathway requires the α2-adrenergic pathway to modify fatty acid skeletal muscle metabolism. To address the physiological relevance of these findings, we demonstrated that this neuromuscular circuit is required to underpin AMPK/ACC signaling activation and fatty acid oxidation after exercise. Last, the selective down-regulation of IL6 receptor in VMH abolished the effects of exercise to sustain AMPK and ACC phosphorylation and fatty acid oxidation in the muscle after exercise. Together, these data demonstrated that the IL6/ERK axis in VMH controls fatty acid metabolism in the skeletal muscle.
Large magnetoelectric resistance in the topological Dirac semimetal α-Sn
Authors: Zhang Yuejie , Kalappattil Vijaysankar , Liu Chuanpu , Mehraeen M. , Zhang Steven S.-L. , Ding Jinjun , Erugu Uppalaiah , Chen Zhijie , Tian Jifa , Liu Kai , Tang Jinke , Wu Mingzhong
Published: July 2022

The spin-momentum locking of surface states in topological materials can produce a resistance that scales linearly with magnetic and electric fields. Such a bilinear magnetoelectric resistance (BMER) effect offers a new approach for information reading and field sensing applications, but the effects demonstrated so far are too weak or for low temperatures. This article reports the first observation of BMER effects in topological Dirac semimetals; the BMER responses were measured at room temperature and were substantially stronger than those reported previously. The experiments used topological Dirac semimetal α-Sn thin films grown on silicon substrates. The films showed BMER responses that are 10
6
times larger than previously measured at room temperature and are also larger than those previously obtained at low temperatures. These results represent a major advance toward realistic BMER applications. Significantly, the data also yield the first characterization of three-dimensional Fermi-level spin texture of topological surface states in α-Sn.
ATP-competitive inhibitors modulate the substrate binding cooperativity of a kinase by altering its conformational entropy
Authors: Olivieri Cristina , Li Geoffrey C. , Wang Yingjie , V.S. Manu , Walker Caitlin , Kim Jonggul , Camilloni Carlo , De Simone Alfonso , Vendruscolo Michele , Bernlohr David A. , Taylor Susan S. , Veglia Gianluigi
Published: July 2022

ATP-competitive inhibitors are currently the largest class of clinically approved drugs for protein kinases. By targeting the ATP-binding pocket, these compounds block the catalytic activity, preventing substrate phosphorylation. A problem with these drugs, however, is that inhibited kinases may still recognize and bind downstream substrates, acting as scaffolds or binding hubs for signaling partners. Here, using protein kinase A as a model system, we show that chemically different ATP-competitive inhibitors modulate the substrate binding cooperativity by tuning the conformational entropy of the kinase and shifting the populations of its conformationally excited states. Since we found that binding cooperativity and conformational entropy of the enzyme are correlated, we propose a new paradigm for the discovery of ATP-competitive inhibitors, which is based on their ability to modulate the allosteric coupling between nucleotide and substrate-binding sites.