bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular insight into coordination sites for substrates and their coupling kinetics in Na+/HCO3− cotransporter NBCe1
Authors: Wu Han , Liu Shiyong , Su Pan , Xie Zhang‐Dong , Gui Tian‐Xiang , Zhao Lei , Liu Ying , Chen Li‐Ming 
Published: February 2022

AbstractThe secondary active transporter NBCe1 couples the transmembrane movement of Na+ and carbonate species with an apparent stoichiometry of 1Na+:2HCO3− (the ‘influx’ mode) or 1Na+ :3HCO3− (the ‘efflux’ mode). Here, we employed molecular biology, electrophysiology and structural biology approaches to investigate the molecular mechanism for the transport coupling of Na+ and HCO3− in NBCe1. In Xenopus oocytes, decreasing extracellular [HCO3−] from 66 to 4 mm progressively decreases the Na+ affinity of NBCe1. However, decreasing [Na+] from 96 to 35 mm has little effect on the HCO3− affinity. The residues responsible for the coordination of Na+ and HCO3− in the substrate pocket of NBCe1 were respectively determined by mutational and molecular simulation studies. Mutation to the residues for HCO3− coordination decreased the affinities of NBCe1 for both Na+ and HCO3−. However, mutation to the residues for Na+ coordination decreased the affinity for Na+ but had little effect on the affinity for HCO3−. Molecular simulation showed that NBCe1 has the capacity to coordinate only two ions of HCO3− or CO32−. We propose that (1) NBCe1 has an ordered substrate‐binding kinetics with the binding of HCO3− preceding that of Na+; (2) NBCe1 operating in the influx mode moves 1Na+ + 2HCO3−, whereas NBCe1 in the efflux mode moves 1Na+ + 1HCO3− + 1CO32−. The substrate‐binding kinetics of NBCe1 is distinct from the known kinetics models of many other Na+‐coupled transporters with Na+ binding preceding the driven solute.
imageKey points
Under physiological conditions, the secondary active transporter NBCe1 can operate in the ‘influx’ mode with an apparent stoichiometry of 1Na+ :2HCO3− or in the ‘efflux’ mode with an apparent stoichiometry of 1Na+:3HCO3−.
NBCe1 has an ordered substrate‐binding kinetics with HCO3− preceding the binding of Na+. The kinetics of NBCe1 is distinct from the known kinetics of many other Na+‐driven cotransporters for which the binding of Na+ usually precedes the driven substrate.
The residues responsible for the coordination of Na+ and those for carbonate species in the substrate‐binding pocket of NBCe1 were determined by mutation and molecular simulation studies.
The substrate‐binding pocket of NBCe1 contains just two coordination sites for HCO3− or CO32−. It is proposed that NBCe1 in the influx mode moves 1Na+ + 2HCO3− across the plasma membrane, whereas NBCe1 in the efflux mode moves 1Na+ +1HCO3− +1CO32−.
Some Studies of Angle Relationships in Metal Cutting
Authors: Creveling J. H. , Jordan T. F. , Thomsen E. G. 
Published: February 2022

Abstract
Free-cutting steel, SAE 1113, in the annealed, and SAE 1115 and SAE 4135 in the cold-rolled condition were studied in orthogonal metal cutting. The feed was varied from 0.002 to 0.010 ipr and the rake angle from 20 to 40 deg, at a surface speed of 30 fpm, using several cutting fluids. This range of rake angles and feeds was in the practical region and permitted obtaining continuous chips. When examining the current theories on the shear angle ϕ, rake angle α, and friction angle β-relationships, it was found that none was in complete agreement with the experimental results. However, the equation λ = ϕ + β − α = const was found to hold approximately for the limited range of variables investigated. It was further found that the friction process on the tool face can be satisfactorily explained as a metal-shearing process, and that the ratio of the shearing stresses on the shear plane and tool face was approximately constant for the experimental data obtained.
Maintenance Factors Affecting Production Costs
Authors: Oberhuber W. F. , Watson C. W. 
Published: February 2022

Abstract
The purpose of this paper is to show how the study of maintenance costs may lead us to a reduction in the total production cost of energy. The major factors that we believe contribute to the level of these costs are discussed. Design, management, planning, organization, and an information-gathering system are the factors that separately and collectively contribute to the total effort. We would suggest that this subject be accorded the benefit of considerably greater open discussion. The results undoubtedly will be reflected in our over-all costs.
Convection Phenomena in Fluids Heated from Below
Authors: Ostrach Simon 
Published: February 2022

Abstract
A review of nearly a century’s research on the effects of heating a fluid from below in a body force field reveals many unusual aspects of the resulting flow which had previously been of meteorological interest only. For horizontal fluid layers, the flow was found to depend on a single parameter (the Rayleigh number). Below certain critical values of the Rayleigh number the configuration is in stable equilibrium; for Rayleigh numbers exceeding the critical either columnar or cellular flows occur with increased heat-transfer rates. It is pointed out herein that configurations with heating from below also are encountered in present-day problems in various fields. A recent experiment and an analysis of fluids heated from below in a vertical enclosure (which more closely simulates current configurations) are discussed and there appears to be a correlation between the previous research for meteorological purposes and new problems of current interest in fluid mechanics and heat transfer.
The Maximum Temperature Profile in Journal Bearings
Authors: Pinkus O. , Sternlicht B. 
Published: February 2022

Abstract
An expression for the circumferential temperature distribution in the mid-section of a journal bearing is derived which in implicit form presents temperature as a function of angle, with bearing geometry and operating conditions as parameters. This relation is obtained from an analysis of the energy balance between shear losses and heat storage in a hydrodynamic journal bearing under the assumption that no heat is lost to the surroundings. A discussion is given on how to locate the maximum temperature in bearings of common design.
Electrohydraulic Servomechanism With an Ultrahigh-Frequency Response
Authors: Eckman D. P. , Taft C. K. , Schuman R. H. 
Published: February 2022

Abstract
This paper presents an analysis of a positional servomechanism of very high performance. This control employs an electronic error transducer which actuates a pilot valve by means of an amplifier and a torque motor to position a hydraulic cylinder. The control was to have a frequency response whose amplitude ratio was nearly 1 to 200 cycles per sec (cps) at an amplitude of 0.001 in. with 100-lb dry friction and a load mass of 200 lb. These specifications were exceeded by the control described herein. The optimum open-loop gain and the closed-loop frequency response are determined by linearizing the system equations and using Laplace transform methods. The system also was analyzed by solving the nonlinear equations on an electronic analog computer to determine optimum gain, transient response, and frequency response. A comparison of the results indicates that for input signals which cause the control to operate outside the region in which the linearizing assumptions apply, the linear analysis still gives results which agree with those of the nonlinear analysis within a factor of three.
On the Analysis of Linear and Nonlinear Systems
Authors: Shinbrot Marvin 
Published: February 2022

Abstract
A general theory of a certain class of commonly used methods for the analysis of linear systems from measured response data will be described. It will then be shown that, when viewed from this general point of vantage, all of these linear techniques can be extended in a natural way to apply to nonlinear systems. In addition, through use of the general theory, a new method, possessing certain advantages over those used previously, will be derived. Finally, the effectiveness of the new method will be illustrated by several examples.
Nonlinear Integral Compensation of a Velocity-Lag Servomechanism With Backlash
Authors: Shen C. N. , Miller H. A. , Nichols N. B. 
Published: February 2022

Abstract
When backlash is encountered in a velocity-lag servomechanism, the system may become unstable. The loop-gain limitation imposed is becoming unacceptable with increasing requirements for following steep ramp inputs as in certain machine-tool control applications. Integral compensation is not applicable since, with backlash, oscillations result. This paper analyzes an attempt to overcome this difficulty by intentionally incorporating a second nonlinearity, a dead zone in the input to the integrator. Results are given which allow the approximate transient response of certain systems to be obtained quickly and the question of stability is considered. Finally, an example of its application is given along with a discussion of several practical factors involved.
Flow Through Annular Orifices
Authors: Bell K. J. , Bergelin O. P. 
Published: February 2022

Abstract
Coefficients for the annular orifice formed between a circular disk and a cylindrical tube are reported for twenty-one orifices having disk diameter to tube diameter ratios in the range of 0.95 to 0.996, and orifice length-to-width ratios from 0.118 to 33.3. The orifice Reynolds-number range is from 2.0 to 20,000 for both tangent and concentric orientations of the disk. Comparison with previous data indicates that the results also apply to the annular orifice formed when a rod extends through a circular hole in a plate. Theoretical and semi-empirical equations are developed to predict coefficients for annular orifices.
Tests of Free Convection in a Partially Enclosed Space Between Two Heated Vertical Plates
Authors: Siegel Robert , Norris R. H. 
Published: February 2022

Abstract
The free-convection heat-transfer coefficients were measured, as a function of spacing, for two parallel, electrically heated, vertical plates. The top of the rectangular space between the plates was left open, and during most of the tests the bottom and sides were closed. The heat input per unit area was substantially uniform, and the Grashof number, based on plate height, was of the order of 1010. The results demonstrate how the surface-temperature rise increases, or the local Nusselt number decreases, as either of the cross-section dimensions of the free-convection space is reduced. This decrease in Nusselt number is less rapid than was expected from purely two-dimensional flow considerations. This is ascribed to the effect of an asymmetrical flow pattern observed in the space. In some cases, a periodic reversal of this asymmetrical flow also was observed. When the space between plates was opened sufficiently at the bottom, the results were reasonably consistent with the correlation proposed by Jakob for a single vertical plate with a turbulent boundary layer; these results were almost independent of spacing between the heated surfaces down to the minimum spacing tested.
Criteria for Validity of Lumped-Parameter Representation of Ducting Air-Flow Characteristics
Authors: Stalzer T. R. , Fiedler G. J. 
Published: February 2022

Abstract
The dynamic characteristics of air flow in a section of ducting involve nonlinear partial differential equations in which the air pressure and weight flow vary with both space and time. Differential equations for the distributed-parameter and the lumped-parameter representations are derived. Using applicable linearizing assumptions, transfer functions are obtained for each representation. The two transfer functions are compared by applying them to a practical valve-and-ducting system selected from a control problem. Since the lumped-parameter representation is more convenient to use in controls design, a simple numerical criterion is developed to determine rapidly the conditions under which lumped representation of a distributed element is valid. Frequency-response and time-response plots for the lumped and distributed elements are included for comparison purposes.
Problems Encountered in the Translation of Compressor Performance From One Gas to Another
Authors: Hartmann M. J. , Wilcox W. W. 
Published: February 2022

Abstract
The problem of translating the performance of a continuous-flow compressor from one gas to another has become of increasing importance from several viewpoints: (a) Under certain circumstances it may be possible to test compressors in a special test medium which extends the useful range of test stand to high power or speed ranges. (b) It may be desirable to apply a given compressor of known performance to the compression of a different gas. (c) The fundametnal information that has been accumulated over the years for air compressors may be useful in improving the performance of compressors for other gases. For single or small numbers of stages the performance for geometrically similar flow at the compressor inlet can be translated rather easily from one gas to another. For large numbers of blade rows, however, the translation of the performance becomes much more difficult. The methods used, however, would indicate the changes necessary to keep the performance level up when a given compressor is applied to some other gas. The experimental methods used in testing compressors in a closed loop using Freon-12 on the test medium are given. The problems of indicating the purity of the test gas and maintaining the desired operating conditions indicate some of the problems compressor test stands using special test medium may encounter. It does appear that special test medium for compressors should be considered as a long-range fundamental study rather than a “quick-fix” extension of existing test facilities.
Analysis of Journal Bearings With Arbitrary Load Vector
Authors: Pinkus O. 
Published: February 2022

Abstract
Starting with the Reynolds equation for finite bearings, a complete set of solutions for various combinations of the parameters α, μ, and L/D was obtained. These data were then used to obtain solutions for bearing operation in which the load vector is located at any arbitrary position with respect to the two oil grooves of a journal bearing. Plotted as functions of the load angle ψ are values for eccentricity, power loss, and oil flow. The plots also provide means of selecting an optimum load angle ψ to obtain highest load capacity, maximum lubricant flow, and least power loss.
On the Adiabatic Couette Flow of a Compressible Fluid
Authors: Hughes W. F. , Osterle J. F. 
Published: February 2022

Abstract
An investigation is made of the adiabatic flow of air between two parallel plates very close together in relative tangential motion with a pressure differential across the moving plate. The solution predicts the “thermal wedge” effect of hydrodynamically lubricated slider-pad bearings and gives a quantitative analysis of the more general problem where a pressure differential exists across the slider pad. The results indicate that the hydrodynamical pressure contribution is often negligible (for moderate speeds) in comparison to the hydrostatic pressures in the pressurized bearings. For the case of stationary plates, the adiabatic solution is identical with the isothermal solution and no temperature rise occurs.
Curved Beams With Eccentric Boundaries
Authors: Vidosic J. P. , Bogardus F. J. , Durden J. C. 
Published: February 2022

Abstract
A study of curved beams having eccentrically positioned circular-arc boundaries is reported upon in this paper. The study involves some mathematical considerations as well as a photoelastic investigation of the stresses in such beams. The results comprise a method of design using the ordinary straight-beam theory but involving stress factors. Both curves and expressions that can be used to obtain the required factors are presented.
Power From Solar Energy
Authors: Yellott J. I. 
Published: February 2022

Abstract
Following a brief historical introduction, the paper points out the need for solar energy to supplement fossil fuels and nuclear power. The nature of solar radiation is described, and methods are given for estimating the amount available at any particular location. Flat-plate and concentrating collectors are discussed, and recent technical advances are reported, including selective surface coatings and new tube-in-sheet materials. Cycles and prime movers are considered. Need for water in vapor-cycle condensers indicates usefulness of hot-air engines. High thermal efficiency is advocated as a means for reducing fixed charges by cutting size of collectors and rejectors.
The Effect of Condensate Reheat on Mean Temperature Difference in Feedwater Heater Subcooling Zones
Authors: Gardner Karl A. 
Published: February 2022

Abstract
Heat leakage through the subcooling zone wall in combination feedwater heaters tends to defeat one purpose of the zone; namely, to subcool the condensate. Equations are presented for the determination of the mean temperature difference, feedwater and condensate-outlet temperatures, and minimum subcooling terminal approach under such conditions. These are given in terms of parameter K = (UsAz/UsAs), the relative heat-transfer capability of the zone envelope as compared to the tube surface enclosed.
Pressure Drop for Parallel Flow Through Rod Bundles
Authors: Le Tourneau B. W. , Grimble R. E. , Zerbe J. E. 
Published: February 2022

Abstract
Friction factors for flow parallel to a rod bundle have been determined experimentally in a Reynolds-number range from approximately 5000 to 100,000. Three rod arrays were used; namely, a 1.20 pitch-to-rod diameter ratio on a square lattice, and a 1.12 pitch-to-rod diameter ratio on both square and equilateral triangular lattices. Entrance plus exit-loss coefficients, and joint loss coefficients between axially aligned rod bundles also were measured experimentally for tube-sheet end connections. For the square arrays, the effect of tube-sheet flow area on these loss coefficients was investigated. Results are presented in graphical form.
An Investigation of the End-Wall Boundary Layer of a Turbine-Nozzle Cascade
Authors: Turner J. R. 
Published: February 2022

Abstract
As a part of a research program aimed at an explanation of the low efficiencies measured near the casings of turbines, an experimental investigation of the flow through a rectilinear cascade of turbine nozzles was conducted to study the effects of the end-wall boundary layer on the flow pattern through the nozzles. Secondary flows in the boundary-layer fluid produce an accumulation of low-energy fluid in the cascade exit plane that is considerably different from the flow field of the two-dimensional wakes. To describe the effects of the secondary flows, detailed data are included showing blade-pressure-distribution variations through the end-wall boundary layer, flow directions, and total and static pressure at cascade discharge, both with and without an inlet boundary layer on the end wall. From these data, qualitative conclusions have been drawn concerning the nature and origin of these low-energy accumulations. The most significant of these conclusions are (a) that the end-wall boundary-layer behavior inside the nozzle passage is essentially independent of the boundary layer entering the cascade; (b) the low-energy fluid which appears in the suction-surface end-wall corner at cascade discharge has its origin only in the end-wall and suction-surface boundary layers.
Method for Presenting the Response of Temperature-Measuring Systems
Authors: Looney Robert 
Published: February 2022

Abstract
A single time-constant approximation of the lag of temperature-measuring systems is often adequate for evaluating the effect of the system lag on the control loop and for indicating the fidelity with which transients are recorded. The value of this approximate time constant is dependent upon the system and on the properties of the fluid whose temperature is being controlled. This paper suggests a method of presenting information on systems from which the user can determine the single time-constant approximation for his operating conditions. Experimental procedures for obtaining the necessary information are discussed.
The Phase-Space Method for Analysis of Nonlinear Control Systems
Authors: Ku Y. H. 
Published: February 2022

Abstract
This paper gives a general procedure for the analysis of a feedback system with a nonlinear control function. Taking the actuating signal as the dependent variable, a single nonlinear differential equation is obtained, the order of which depends upon the complexity of the linear transfer functions. This high-order nonlinear differential equation is then solvable by the phase-space method developed by the author and detailed in his previous papers (1, 2, 3). The method is further extended to the analysis of a system with one nonlinear controller in the forward branch and another nonlinear controller in the feedback branch. The two phase-plane equations obtained from the simultaneous differential equations are then solvable by the method given in reference (4).
The Flow and Fracture of Nodular Cast Iron
Authors: Clough W. R. , Shank M. E. 
Published: February 2022

Abstract
Combined stress tests on pearlitic nodular iron show this material possesses a constant valued modulus of elasticity and Poisson’s ratio. The maximum shear criterion for yielding is conservative, but is sufficiently accurate for design purposes. In addition, it appears to yield in accordance with the distortion-energy theory, providing stress concentrations at the graphite nodules are taken into account. There is a density change with plastic deformation due to separation of the matrix from the graphite. Stress and strain variables may be reasonably correlated by plotting plastic work against octahedral shear stress. A smooth fracture envelope has been obtained, and fracture occurs in a direction normal to the greatest applied tensile stress. A considerable internal crack network may be opened up before fracture. Brittle cleavage facets in pearlitic nodular iron are revealed by the fractographic technique. Cleavage fracture is not obtained in ferritic nodular iron in tension, but may be obtained in the presence of notches or by low temperature of test.
Design and Development of a Two-Cycle Turbocharged Diesel Engine
Authors: Louzecky P. J. 
Published: February 2022

Abstract
The development of a successful design of two-cycle diesel engines for turbocharging involves many difficult problems, such as integrating the turbocharger to the engine, developing an exhaust manifold that will result in a minimum loss of heat energy, and making the engine components sufficiently rugged to carry the increase in engine loads. A solution to these problems, obtained by intensive study and testing, is presented in this paper. Also described are the favorable results achieved, which are improved fuel consumption, increased engine horsepower, and decreased engine size per horsepower as compared with nonturbocharged two-cycle diesel engines.
Media Presentations of Olympic Victories and Nation-Related Identification Among Viewers: The Influence of Emotions Induced by Sportscasts
Authors: Mutz Michael , Gerke Markus 
Published: February 2022

This study uses experimental methods to assess the causal effect of media presentations on viewer’s emotions, national identification, and nation-related values. In three experiments covering marginal sports disciplines, viewers watched broadcasts of compatriots winning an Olympic gold medal, either featuring emotional and partisan reporting styles or a neutral audio commentary. Findings show that those exposed to the partisan commentary experienced heightened emotions; identified more strongly with their nation; exhibited more patriotism and nationalism; and ascribed positive values (e.g., achievement, diligence) more strongly to their home country than did viewers in the control group. These results suggest that the broadcasting styles influence viewers’ emotions, attitudes, and collective identifications beyond the effects of the sporting competition itself.