bluuebunny/crossref_metadata_2025_split huggingface dataset:
Certification systems for machine learning: Lessons from sustainability
Authors: Matus Kira J.M. , Veale Michael 
Published: June 2021

AbstractConcerns around machine learning’s societal impacts have led to proposals to certify some systems. While prominent governance efforts to date center around networking standards bodies such as the Institute of Electrical and Electronics Engineers (IEEE), we argue that machine learning certification should build on structures from the sustainability domain. Policy challenges of machine learning and sustainability share significant structural similarities, including difficult to observe credence properties, such as data collection characteristics or carbon emissions from model training, and value chain concerns, including core‐periphery inequalities, networks of labor, and fragmented and modular value creation. While networking‐style standards typically draw their adoption and enforcement from functional needs to conform to enable network participation, machine learning, despite its digital nature, does not benefit from this dynamic. We therefore apply research on certification systems in sustainability, particularly of commodities, to generate lessons across both areas, informing emerging proposals such as the EU’s AI Act.
A Theoretical Analysis of the Viscous Flow in a Narrowly Spaced Radial Diffuser
Authors: Woolard Henry W. 
Published: June 2021

Abstract
A theoretical method for calculating the radial pressure distribution for laminar viscous flow in a narrowly spaced radial diffuser having arbitrarily shaped walls deviating only moderately from a plane surface is developed. The analysis as it stands is also directly applicable to turbulent flow in the initial inlet region of a diffuser. Additional work is necessary to obtain a complete turbulent-flow analysis. Pressure distributions calculated by the laminar-flow theory show reasonably good agreement with the limited experimental pressure distributions available at the time of the analysis. Fairly good agreement also is obtained for the performance of a disk-valve element.
The Synthesis of Four-Bar Mechanisms by the Method of Components
Authors: Hirschhorn J. 
Published: June 2021

Abstract
The synthesis of four-bar mechanisms based on the vectorial representation of links in complex form was first suggested by S. Bloch. His work was further developed by R. Beyer and N. Rosenauer. These kinematicians investigated the synthesis of the four-bar mechanism for prescribed instantaneous angular velocities and accelerations of the three moving links. This paper presents a somewhat different approach to the problem, in that the vectors are being resolved into Cartesian components. This method permits the synthesis for prescribed conditions concerning angular velocities, accelerations, and lengths of links. The author believes that the simpler treatment will make this method more readily acceptable to engineers.
The State Principle—Some General Aspects of the Relationships Among the Properties of Systems
Authors: Kline S. J. , Koenig F. O. 
Published: June 2021

Abstract
An independent generalization, here called the “State Principle,” is necessary for the development of thermodynamics. Previously, this principle has been either tacitly assumed, or at best stated incompletely. A discussion and explicit formulation of this principle are given. The Phase rule is deduced from the State Principle and certain related empirical information. In this derivation no reference whatsoever is made to the First Law or the Second Law of Thermodynamics. A new, simple, systematic means for counting the number of components in the phase rule, which has no known exceptions and which does not rely on either advanced thermodynamics or the First and Second Laws, is presented. Examples of its use are included.
Longitudinal Impact of a Semi-Infinite Circular Elastic Bar
Authors: Skalak Richard 
Published: June 2021

Abstract
The impact of a semi-infinite elastic bar of circular cross section is studied using the equations of motion of linear-elasticity theory and a method of double-integral transforms. An evaluation of the solution is obtained using approximations which are valid for large values of the time after the initial impact. The numerical results show a continuous dispersion of the wave front and an oscillation which are not found in the usual elementary-theory solution.
Yield Loads of Slabs With Reinforced Cutouts
Authors: Hodge P. G. , Perrone Nicholas 
Published: June 2021

Abstract
A method of computing upper and lower bounds on the carrying capacity of a plane slab with a reinforced cutout is presented. The slab is subjected to a uniaxial load which is either uniform or applied by means of a perfectly rigid clamp. The results are applied to several examples and are found to agree quite well with experimental values.
Analog Computer for Nonlinear System With Hysteresis
Authors: Thomson W. T. 
Published: June 2021

Abstract
Structural materials loaded beyond the elastic limit generally display a hysteresis effect such that recovery from maximum deflection proceeds elastically. Assuming a spring-mass model for such a structure to exist, where the stiffness is represented by segments of straight lines, its solution under dynamic excitation still offers sufficient difficulties to welcome a computer technique which will automatically perform this task. This paper describes an electronic analog computer scheme which will carry out such a solution for a unidirectional force excitation.
Collapse Strength of Redundant Beams After Lateral Buckling
Authors: Masur E. F. , Milbradt K. P. 
Published: June 2021

Abstract
According to classical linear theory, slender beams buckle laterally under vertical loads which remain constant as the buckling amplitude increases. Unless prior yielding takes place, the loads corresponding to neutral equilibrium represent therefore the collapse strength of the beam. However, the inclusion of nonlinear terms in the strain-displacement relations modifies the predicted postbuckling behavior of redundant beams. If continued elasticity is postulated, increasing amplitudes are associated with increasing load magnitudes, which generally approach limiting values. These “ultimate loads” may be estimated by means of two principles establishing lower and upper bounds. Tests performed on a single-span beam of varying degrees of end restraint show good agreement with the proposed theory.
A Numerical Procedure for Calculating the Large Deflections of Straight and Curved Beams
Authors: Seames A. E. , Conway H. D. 
Published: June 2021

Abstract
Paper presents a numerical method for calculating the large deflections of beams, assuming that the elastic axis can be approximated to by a number of circular arcs tangent to one another at their points of intersection. The calculations are made in tabular form, and are illustrated by particular examples of straight and curved cantilever beams and of rings subjected to concentrated or distributed loads. In those cases where an exact solution is possible, excellent agreement with the present method was obtained.
Analysis of Stresses and Strains Near the End of a Crack Traversing a Plate
Authors: Irwin G. R. 
Published: June 2021

Abstract
A substantial fraction of the mysteries associated with crack extension might be eliminated if the description of fracture experiments could include some reasonable estimate of the stress conditions near the leading edge of a crack particularly at points of onset of rapid fracture and at points of fracture arrest. It is pointed out that for somewhat brittle tensile fractures in situations such that a generalized plane-stress or a plane-strain analysis is appropriate, the influence of the test configuration, loads, and crack length upon the stresses near an end of the crack may be expressed in terms of two parameters. One of these is an adjustable uniform stress parallel to the direction of a crack extension. It is shown that the other parameter, called the stress-intensity factor, is proportional to the square root of the force tending to cause crack extension. Both factors have a clear interpretation and field of usefulness in investigations of brittle-fracture mechanics.
Axisymmetric Thermal Stresses in a Spherical Shell of Arbitrary Thickness
Authors: McDowell E. L. , Sternberg E. 
Published: June 2021

Abstract
This paper contains an explicit series solution, exact within the classical theory of elasticity, for the steady-state thermal stresses and displacements induced in a spherical shell by an arbitrary axisymmetric distribution of surface temperatures. The corresponding solutions for a solid sphere and for a spherical cavity in an infinite medium are obtained as limiting cases. The convergence of the series solutions obtained is discussed. Numerical results are presented appropriate to a solid sphere if two hemispherical caps of its boundary are maintained at distinct uniform temperatures.
Saint Venant’s Principle: A Biharmonic Eigenvalue Problem
Authors: Horvay G. 
Published: June 2021

Abstract
Saint Venant’s principle is formulated as a biharmonic eigenvalue problem for the symmetrical truncated wedge x ≥ 0, |y| ≤ yb (yb = 1 + x tan ω) which is stress-free along the lateral edges, and is loaded by self-equilibrating shear and normal tractions τko(y), σko(y) along edge x = 0. It is found that for the wedge angle 2ω = 0 the law of decay is of the type e−αkτ; for 2ω ≠ 0 the law of decay is of type r−μk; μk is minimum for 2ω = π. The indexes k attached to τo, σo indicate that we deal with systems of characteristic tractions which produce characteristic decay rates. Practical implications of the results, as they apply to structural design, are discussed in a separate paper, “Some Aspects of Saint Venant’s Principle.”
Buckling of Thin Cylindrical Shell Under Hoop Stresses Varying in Axial Direction
Authors: Hoff N. J. 
Published: June 2021

Abstract
The buckling of a thin cylindrical shell simply supported along the perimeter of its end sections is analyzed under hoop compressive stresses varying in the axial direction. The thermal stresses arising from a uniform increase in the temperature of the cylinder are determined. It is found that such thermal stresses are not likely to cause elastic buckling. Simple approximate formulas are developed for buckling stress and thermal stress.
Interaction Curves for Shear and Bending of Plastic Beams
Authors: Hodge P. G. 
Published: June 2021

Abstract
Interaction curves are presented for plastic beams subject to combined shear and bending. A general formula is obtained and specific curves are drawn for rectangular and I-sections. A simply supported beam with a concentrated load is considered as an example. The results are compared with those of simple beam theory and with available plane-stress solutions. It is concluded that the elementary theory is adequate for height-to-length ratios of less than 0.1, while the present theory is useful in the range from 0.1 to 1.0.
Reduction of Three-Dimensional Stress Distributions to Two-Dimensional Analysis by Superposition
Authors: Zizicas G. A. 
Published: June 2021

Abstract
In a recent note the author proposed a graphical procedure which supplements the classical three-dimensional Mohr-circle representation by specifying the direction of the total shear on any element of surface. The same results are reached here by superposition which simplifies and clarifies the analysis considerably. The associated analytical results are presented in a more useful form and are shown to lead readily to the classical Mohr representation. An application is made to the practically important stress components on the octahedral planes.
A Method for Solving Problems of Irrotational Gas Flow by Means of High-Speed Digital Computers
Authors: Koga Toyoki 
Published: June 2021

Abstract
A numerical procedure is proposed for solution of certain problems in steady gas flow where subsonic, sonic, and supersonic regions appear simultaneously. The difficulties that occur in analytical methods for taking into account the differences of the type of the fundamental equation (elliptic, parabolic, hyperbolic) are avoided. Given a streamline and the state of the gas along that streamline, the co-ordinates of the neighboring streamline and the state of the gas along it can be computed. The procedure can be applied successively to cover a flow field. The method is described in detail for two-dimensional, steady, irrotational flow (without shocks) of a perfect gas, and an example is given.
A Photoelastic Study of Maximum Tensile Stresses in Simply Supported Short Beams Under Central Transverse Impact
Authors: Betser A. A. , Frocht M. M. 
Published: June 2021

Abstract
Simply supported short Castolite beams of uniform rectangular cross section were subjected to central transverse impact by a heavy mass. Photoelastic streak photographs were taken of the transverse section of symmetry for a wide range of spans, widths, and impact velocities at exposures of less than 1 microsec. The maximum tensile stresses were determined. Comparison with the elementary theory for long beams shows that while this theory is satisfactory for long beams, it does not agree with the results from short beams. An approximate theory for short beams under central impact is developed which gives satisfactory agreement. The duration of impact also was determined and the appearance of isotropic points is discussed.
Superharmonic Oscillations as Solutions to Duffing’s Equation as Solved by an Electronic Differential Analyzer
Authors: Atkinson C. P. 
Published: June 2021

Abstract
This paper presents the experimental response curves for the solutions of Duffing’s equation for that frequency range where higher-order harmonics (called superharmonics as opposed to lower order or subharmonics) of the fundamental are important components of the solution. The experimental results were obtained by solving Duffing’s equation on an electronic differential analyzer. The paper presents corroboration of analytical results for the third-order superharmonic component of solutions which were calculated by a two-term Ritz approximation. The results of this paper indicate that superharmonics of higher order than the third, that is, fifth and seventh order, and even-order harmonics such as second and fourth order can be found in the frequency range studied. This paper points out a definite relationship which exists between the superharmonic generated and the free-vibration curve (“backbone”) of the system. For example, if we compare the maximum displacement of the solution containing an nth order superharmonic with the same amplitude of the free-vibration curve, it is seen that the frequency of the fundamental (the forcing frequency) is 1/n times this natural frequency or, conversely, the frequency of the superharmonic component is n times that of the fundamental and has in fact the frequency of the free vibration for that amplitude. Thus a superharmonic of order n can be pictured as a sustained free vibration which is generated when the frequency of the forcing function is 1/n of the frequency of the free-vibration response curve. The phenomenon of superharmonic oscillations is pictured here as a nonlinear resonance. Experimental evidence of the superharmonic-jump phenomenon as discovered analytically by John Burgess (1) also is presented in this paper.
A Donnell Type Theory for Asymmetrical Bending and Buckling of Thin Conical Shells
Authors: Seide Paul 
Published: June 2021

Abstract
Equations, somewhat more accurate than those recently presented by N. J. Hoff, are derived for bending and buckling of thin circular conical shells under arbitrary loading. These equations reduce to Donnell’s equations for thin cylindrical shells when the cone semivertex angle becomes very small and the minimum radius of curvature of the median surface approaches a constant value. At the other end of the scale the equations reduce to the well-known equations for flat circular plates when the cone semivertex angle approaches a right angle. In addition, for the entire range of cone semivertex angles the equations reduce to the known equations for axisymmetrical bending when variations of the displacements around the circumference vanish. The problem of bending is reduced to the solution of a single fourth-order partial differential equation with variable coefficients.
The Sector Problem
Authors: Horvay G. , Hanson K. L. 
Published: June 2021

Abstract
On the basis of the variational method, approximate solutions f k ( r ) h k ( θ ) , f k ( r ) g k ( θ ) , F k ( θ ) H k ( r ) , F k ( θ ) G k ( r ) of the biharmonic equation are established for the circular sector with the following properties: The stress functions fkhk create shear tractions on the radial boundaries; the stress functions fkgk create normal tractions on the radial boundaries; the stress functions FkHk create both shear and normal tractions on the circular boundary, and the stress functions FkGk create normal tractions on the circular boundary. The enumerated tractions are the only tractions which these function sets create on the various boundaries of the sector. The factors fk(r) constitute a complete set of orthonormal polynomials in r into which (more exactly, into the derivatives of which) self-equilibrating normal or shear tractions applied to the radial boundaries of the sector may be expanded; the factors Fk(θ) constitute a complete set of orthonormal polynomials in θ into which shear tractions applied to the circular boundary of the sector may be expanded; and the functions Fk″ + Fk constitute a complete set of non-orthogonal polynomials into which normal tractions applied to the circular boundary of the sector may be expanded. Function tables, to facilitate the use of the stress functions, are also presented.
The Elastic Coefficients of the Theory of Consolidation
Authors: Biot M. A. , Willis D. G. 
Published: June 2021

Abstract
The theory of the deformation of a porous elastic solid containing a compressible fluid has been established by Biot. In this paper, methods of measurement are described for the determination of the elastic coefficients of the theory. The physical interpretation of the coefficients in various alternate forms is also discussed. Any combination of measurements which is sufficient to fix the properties of the system may be used to determine the coefficients. For an isotropic system, in which there are four coefficients, the four measurements of shear modulus, jacketed and unjacketed compressibility, and coefficient of fluid content, together with a measurement of porosity appear to be the most convenient. The porosity is not required if the variables and coefficients are expressed in the proper way. The coefficient of fluid content is a measure of the volume of fluid entering the pores of a solid sample during an unjacketed compressibility test. The stress-strain relations may be expressed in terms of the stresses and strains produced during the various measurements, to give four expressions relating the measured coefficients to the original coefficients of the consolidation theory. The same method is easily extended to cases of anisotropy. The theory is directly applicable to linear systems but also may be applied to incremental variations in nonlinear systems provided the stresses are defined properly.
Low-temperature thermochronology constraints on the evolution of the Eastern Kunlun Range, northern Tibetan Plateau
Authors: Wu Chen , Li Jie , Ding Lin 
Published: June 2021

AbstractSignals of uplift and deformation across the Tibetan Plateau associated with the Cenozoic India-Asia collision can be used to test debated deformation mechanism(s) and the growth history of the plateau. The spatio-temporal evolution of the Eastern Kunlun Range in northern Tibet provides a window for understanding the intracontinental tectonic evolution of the region. The Eastern Kunlun Range exposes the Cenozoic Kunlun left-slip fault and kinematically linked thrust belts. In this contribution, integrated field observations and apatite fission-track thermochronology were conducted to constrain the initiation ages of localized thrust faults and the exhumation history of the Eastern Kunlun Range. Our analyses reveal four stages of cooling of the Eastern Kunlun Range. We relate these four stages to the following interpreted tectonic evolution: (1) an initial period of early Cretaceous cooling and slow exhumation over the early Cenozoic, which is associated with the formation of a regional unconformity observed between Cretaceous strata and early Cenozoic sediments; (2) rapid Oligocene cooling that occurred at the eastern domain of the Eastern Kunlun Range related to the southern Qaidam thrusts; (3) extensive rapid cooling since the early-middle Miocene in most of the eastern-central domains and significant uplift of the entire range; and (4) a final pulse of rapid late Miocene-to-present cooling associated with the initiation of the Kunlun left-slip fault and dip-slip shortening at the western and eastern termination of the left-slip fault. Early Cenozoic deformation was distributed along the northern extent of the Tibetan Plateau, and overprinting out-of-sequence deformation migrated back to the south with the initiation of Miocene-to-present deformation in the Eastern Kunlun Range.
Interaction of Peptides Containing CRAC Motifs with Lipids in Membranes of Various Composition
Authors: Volynsky P. E. , Galimzyanov T. R. , Akimov S. A. 
Published: June 2021

Abstract
The lateral distribution of integral and peripheral proteins, as well as lipids in the plasma membranes of mammalian cells is extremely heterogeneous. It is believed that various lipid-protein domains are formed in membranes. Domains enriched in sphingomyelin and cholesterol are called rafts. It is assumed that the distribution of proteins into rafts is largely related to the presence in their primary sequence of a specific amino acid region called the CRAC motif, which is responsible for cholesterol binding. In this work, the interaction of two peptides containing CRAC motifs in their structure with membranes of different compositions was studied by means of molecular dynamics. It has been shown that the average number of lipid molecules in contact with each peptide is proportional to the mole fraction of lipid in the membrane. The predominant interaction of peptides with cholesterol was not observed. In addition, cholesterol did not form long-lived contacts with any amino acid or amino acid sequence. We suppose that in some cases the predominant lateral distribution of peptides and proteins containing CRAC motifs into rafts may be due to amphipathicity of the CRAC motif rather than due to specific strong binding of cholesterol.
JAK 2 positive myeloproliferative neoplasm presenting as stroke, recurrent TIA and isolated third nerve palsy
Authors: Bolaji Paul , Das Saugata , Ahmad Nasar 
Published: June 2021

A man in his early 40s with no significant vascular risk factors was managed within a period of 6 months for recurrent vascular events: ischaemic stroke, transient ischaemic attack and isolated third nerve palsy. He was extensively investigated throughout the course of illness. The only potential aetiological factor identified was a positive janus kinase 2 (JAK 2) mutation after screening on account of mildly elevated platelet count noted during his most recent admission. Bone marrow aspiration confirmed essential thrombocythaemia. He was started on hydroxycarbamide and has remained relatively symptom free since then.This case reiterates the known associations between thrombosis and JAK 2 mutation even without overt myeloproliferative neoplasms. It also highlights the need for specialists in stroke to consider screening for JAK 2 mutation in a young patient with cryptogenic stroke with or without polycythemia or thrombocytosis.