bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predictors of appropriate shock after generator replacement in patients with an implantable cardioverter defibrillator
Authors: Arcinas Liane A. , Chew Derek S. , Seifer Colette M. , Baranchuk Adrian , Supel Izabella , Exner Derek V. , Boles Usama , McIntyre William F. 
Published: April 2021

AbstractBackgroundImplantable cardioverter defibrillators (ICDs) are indicated for the primary prevention of sudden cardiac death in patients with reduced left ventricular ejection fraction (LVEF). The ongoing risk/benefit profile of an ICD at generator replacement is unknown. This study aimed to identify predictors of appropriate ICD shocks and therapies after first ICD generator replacement, and its procedure‐related complications.MethodsWe conducted a multicenter, retrospective cohort study including patients with primary prevention ICDs who underwent generator replacement between April 2005 and July 2015 at three Canadian centers. The primary and secondary outcomes were appropriate ICD shock and any appropriate ICD therapy, respectively. Procedure‐related complication rates were also reported.ResultsOf the 219 patients in the cohort, 61 (28%) experienced an appropriate shock while 40 (18%) experienced appropriate antitachycardia pacing over a median follow up of 2.2 years. Independent predictors of appropriate ICD shocks included: LVEF at time of replacement (adjusted odds ratio [OR] 0.4 per 10% increase in LVEF, P < .001), a history of appropriate ICD shocks prior to replacement (OR 4.9, P < .001), and a history of inappropriate ICD shocks (OR 4.2, 95%, P < .002). Similar predictors were identified for the secondary outcome of any appropriate ICD therapy. Device‐related complications were reported in 25 (11%) patients, with 1 (0.5%) resulting in death, 14 (6.3%) requiring site re‐operation, and 6 (2.7%) requiring cardiac surgical management.ConclusionNot all primary prevention ICD patients undergoing generator replacement will require appropriate device therapies afterwards. Generator replacement is associated with several risks that should be weighed against its anticipated benefit. A comprehensive assessment of the risk‐benefit profile of patients undergoing generator replacement is warranted.
Treading the Thin Line: Pharmacy Workers’ Perspectives on Medication Abortion Provision in Lusaka, Zambia
Authors: Footman Katharine , Chelwa Nachela , Douthwaite Megan , Mdala James , Mulenga Drosin , Brander Caila , Church Kathryn 
Published: April 2021

Context: Despite liberal abortion laws, safe abortion access in Zambia is impeded by limited legal awareness, lack of services, and restrictive clinical policies. As in many countries with restricted abortion access, women frequently seek abortions informally from pharmacies.Methods: We conducted 16 in‐depth interviews in 2019 to understand the experiences and motivations of pharmacy workers who sell medication abortion (MA) drugs in Lusaka.Results: We found that pharmacy staff reluctantly assume a gatekeeper role for MA due to competing pressures from clients and from regulatory constraints. Pharmacy staff often decide to provide MA, motivated by their duty of care and desire to help clients, as well as financial interests. However, pharmacy workers’ motivation to protect themselves from legal and business risk perpetuates inequalities in abortion access, as pharmacy workers improvise additional eligibility criteria based on personal risk and values such as age, partner approval, reason for abortion, and level of desperation.Conclusion: These findings highlight how pharmacy staff informally determine women's abortion access when laws and policies prevent comprehensive access to safe abortion. Reform of clinical guidelines, public education, strengthened public sector availability, task sharing, and improved access to prescription services are needed to ensure women can legally access safe abortion.
A global phylogenetic analysis of trap‐jaw ants, Anochetus Mayr and Odontomachus Latreille (Hymenoptera: Formicidae: Ponerinae)
Authors: Fernandes Itanna O. , Larabee Fredrick J. , Oliveira Marcio L. , Delabie Jacques H. C. , Schultz Ted R. 
Published: April 2021

AbstractWe present a phylogeny of the trap‐jaw ant genera Anochetus and Odontomachus with dense taxon sampling representing all biogeographical regions and all species groups for both genera. Four nuclear protein‐coding genes (Long‐wavelength rhodopsin, Topoisomerase I, Wingless and Rudimentary) and one mitochondrial gene (cytochrome oxidase I) were sequenced for 221 individuals of Anochetus (44 species) and Odontomachus (38 species). Analyses using Bayesian and maximum‐likelihood criteria recovered essentially the same phylogenetic relationships, including strongly supported reciprocal monophyly of both genera. The analyses recovered nine of the 12 species groups previously proposed for Odontomachus and nine of the 22 species groups previously proposed for Anochetus. Based on these results, species groups are redefined. Anochetus contained an additional new, previously unrecognized group defined here as the hohenbergiae group. Divergence‐time analyses estimated the clade composed of Odontomachus + Anochetus arose during the early Paleocene, with Odontomachus and Anochetus diverging during the Eocene. Biogeographic analyses suggest that the most recent common ancestor (MRCA) of Odontomachus and Anochetus occupied either the Neotropical or Afrotropical region during the late Cretaceous and that the two genera radiated during the early Paleocene. The ancestor of Odontomachus originated in the Neotropical or Afrotropical regions, giving rise to lineages that radiated during the late Eocene, and the ancestor of Anochetus originated in the Neotropical region, giving rise to lineages that radiated during the early Eocene.
A Method of Numerical Analysis of Plastic Flow in Plane Strain and Its Application to the Compression of a Ductile Material Between Rough Plates
Authors: Hill R. , Lee E. H. , Tupper S. J. 
Published: April 2021

Abstract
Problems of plastic flow which arise in practice, with complicated boundary conditions, are seldom amenable to exact analysis, and it becomes necessary to devise some numerical method of solution. This paper describes a rapid numerical procedure for the determination of the stress and velocity distributions in plane plastic flow where the plastic strains are large. The method is applied to the problem of the squeezing of a plastic material between rough plates. This example has been chosen as it illustrates the treatment of most types of boundary condition likely to be encountered and supplies for contrast several incomplete solutions attempted by previous authors. The solution shows the fallacy of the apparent static determinancy of the plane plastic problem, indicating the need to consider the velocity field in obtaining the true distribution of stress. A further advantage of this example is the possibility of checking the numerical procedure, which is found to be extremely accurate.
The Solution of Elastic Plate Problems by Electrical Analogies
Authors: MacNeal R. H. 
Published: April 2021

Abstract
A dynamic-analogy method for the solution of elastic plate problems is described in this paper. The electrical circuits developed here can be set up and studied on an electric-analog computer. Problems involving deflections under constant load, transient vibrations, or normal modes can be solved in this way. The method of applying boundary conditions to plates with irregular edges is given, together with a detailed description of the representation of the boundary conditions for a rectangular variable-thickness plate. Solutions that have been obtained on the Cal Tech electric-analog computer are presented for the static deflections and normal modes of a rectangular cantilever plate.
Some Thin-Plate Problems by the Sine Transform
Authors: Deverall L. I. , Thorne C. J. 
Published: April 2021

Abstract
General expressions for the deflection of thin rectangular plates are obtained for cases in which two opposite edges have arbitrary but given deflections and moments. The sine transform is used as a part of the method of solution, since solutions can be found for an arbitrary load for each set of edge conditions at the other two edges. Even for the classical cases, the use of the sine transform makes the process of solving the problem much easier. The six general solutions given are those which arise from all possible combinations of physically important edge conditions at the other two edges. Solutions for a specific load function can be found by integration or by the use of a table of sine transforms. Tables useful in application of the method to specific problems are included.
Bending of Thin Ring-Sector Plates
Authors: Deverall L. I. , Thorne C. J. 
Published: April 2021

Abstract
General expressions for the deflection of plates whose planform is a sector of a circular ring are given for cases in which the straight edges have arbitrary but given deflection and bending moment. The solutions are given for all combinations of physically important edge conditions on the two circular edges. Sectors of circular plates are included as special cases. Solutions are given for a general load which is a continuous function of r, and a sectionally continuous function of θ, where r and θ are the usual polar co-ordinates with the pole at the center of the ring. Several specific examples are given.
Plastic-Wave Propagation Effects in High-Speed Testing
Authors: Lee E. H. , Wolf H. 
Published: April 2021

Abstract
A material test carried out at high speed may be markedly influenced by plastic-wave propagation effects. In such a case, a variation of strain occurs along the test specimen, and the stress-strain relation cannot be determined from measurements made on the specimen as a whole. If average values are taken, it is shown that a spurious strain-rate influence will be deduced when propagation effects first begin to appear as the testing speed is increased. The effect is due not to a true material strain-rate dependence, but to the appearance of strain variations along the specimen, and its magnitude depends upon the dynamics of the whole test arrangement. The theoretical plastic-wave analysis of a particular test arrangement is also given. The range of speed is determined which permits satisfactory interpretation without the need for detailed analysis of plastic-wave propagation. Application to other test arrangements is discussed, and it is pointed out that a theoretical analysis can, in general, be made to predict the permissible speed range in planning a high-speed testing program.
Bending of a Cylindrically Aeolotropic Circular Plate With Eccentric Load
Authors: Sen Gupta A. M. 
Published: April 2021

Abstract
The problem of small-deflection theory applicable to plates of cylindrically aeolotropic material has been developed, and expressions for moments and deflections produced have been found by Carrier in some symmetrical cases under uniform lateral loadings and with different boundary conditions. The author has also found the moments and deflection in the case of an unsymmetrical bending of a plate loaded by a distribution of pressure of the form p = p0r cos θ, with clamped edge. The object of the present paper is to investigate the problem of the bending of a cylindrically aeolotropic circular plate of uniform thickness under a concentrated load P applied at a point A at a distance b from the center, the edge being clamped.
Supersonic Flow With Variable Specific Heat
Authors: Durham F. P. 
Published: April 2021

Abstract
Formulas are developed for stagnation conditions and one-dimensional flow through shock waves, including Rankine-Hugoniot values, taking into account the variation of the specific heat of air with temperature by means of the concept of mean specific heats. These formulas are reduced to correction factors that may be applied to the widely used constant specific-heat formulas up to a Mach number of 7. The corrections involved are appreciable in the case of the density change through a shock wave and for the total pressure ratio across a shock wave, as well as for stagnation pressures and temperatures. The limitations imposed by the deviation of a gas at high pressure from the ideal equation of state, relaxation time, and dissociation are discussed.
A Contribution to the Theory of the Development and Stability of Detonation in Gases
Authors: Oppenheim A. K. 
Published: April 2021

Abstract
The development of detonation of an explosive gas mixture contained in a constant-cross-section duct is analyzed on the basis of a unidimensional, gasdynamic treatment of a double-discontinuity combustion system. A steady and an unsteady system are considered, and it is shown that the latter yields an adequate explanation of the effect of coalition of the two discontinuities on the establishment and subsequent stability of the detonation wave. The locus of states behind the detonating combustion zone during the development of the process is determined and analyzed.
Measurement of Recovery Factors and Friction Coefficients for Supersonic Flow of Air in a Tube: 2—Results Based on a Two-Dimensional Flow Model for Entrance Region
Authors: Kaye J. , Toong T. Y. , Shoulberg R. H. 
Published: April 2021

Abstract
The first part of a program to obtain reliable data on the rate of heat transfer to air moving at supersonic speeds in a tube has been devoted to measurements made on adiabatic supersonic flow of air in a tube. The details of these measurements have been described in a previous paper. The calculated quantities such as the local apparent friction coefficient, recovery factor, Mach number, and so forth, were obtained from the simple one-dimensional flow model for which the properties of the stream are uniform at any section, and boundary-layer effects are ignored. The analysis of some of the same data given in the previous paper is undertaken here with the aid of a simplified two-dimensional flow model. The supersonic flow in the tube is divided into a supersonic core of variable mass with the fluid remaining in the core undergoing a reversible adiabatic change of state, and a laminar boundary layer of variable mass. The compressible laminar boundary layer increases in thickness in the direction of flow, and then undergoes a transition to a turbulent boundary layer. The two-dimensional flow model is limited here to the region where a laminar boundary layer appears to be present in the entrance region of the tube. The results of the analysis based on the two-dimensional flow model indicate that where the flow in the tube boundary layer appears to be laminar, the measured pressures and temperatures in the tube for adiabatic supersonic flow of air could have been predicted, with sufficient accuracy for engineering problems, from measured data for supersonic flow of air over a flat plate with a laminar boundary layer, and with zero pressure gradient.
Heat Conduction in a Compressible Fluid
Authors: Cole J. D. , Wu T. Y. 
Published: April 2021

Abstract
The conduction of heat in a compressible fluid medium is studied in this paper. The compressibility of the fluid has the important effect that an excess of heat is not only carried away by conduction but also causes a pressure wave to move in the fluid. A closely related problem is the effect of heat conduction on the propagation of sound waves in a gas. In both cases the total energy is divided between thermal and pressure waves.
A Progressing-Wave Approach to the Theory of Blast Shock
Authors: Newton R. G. 
Published: April 2021

Abstract
This paper deals with a theoretical description of the motion of a spherical shock wave in a homogeneous medium, such as a blast shock in free air. In order to facilitate such a treatment, a simple assumption concerning the flow is made. The concept of a “progressing wave” as used in this paper is explained and compared with that used by other authors. A simple assumption is made about the motion of the progressing wave, and on its basis an ordinary second-order differential equation for the shock front is derived. Conservation of energy in the shock sphere reduces this to an ordinary first-order differential equation. Examination of the asymptotic behavior of the wave reveals that the original assumption in its simplest form contradicts conservation of energy. The original assumption is then suitably modified and the resulting new equations derived, including asymptotic values. Values for the high-pressure approximation, i.e., near the center of the explosion, are derived, and finally asymptotic as well as high-pressure values are derived for the pressure decay behind the shock front.
Bending With Axial Force of Curved Bars in Plasticity
Authors: Phillips Aris 
Published: April 2021

Abstract
The problem of symmetrical pure bending with axial force of a curved bar in plasticity is considered. A method is given for finding the axial load and bending moment which produce a given strain distribution. This method is based upon approximating the stress-strain curves by means of broken lines. By increasing the number of sides of these broken lines it is possible to solve our problem with as high accuracy as is desired.
Limit Design of a Full Reinforcement for a Circular Cutout in a Uniform Slab
Authors: Weiss H. J. , Prager W. , Hodge P. G. 
Published: April 2021

Abstract
A thin square slab with a central circular cutout reinforced by a concentric ring is subjected to uniform tensions Tx and Ty on the exterior edges. It is desired to determine the dimensions of the reinforcement if the slab is not to collapse under any load which could be supported by a similar slab without any cutout or reinforcement. It is assumed that the slab and reinforcement are made of a perfectly plastic material which satisfies the Tresca yield criterion of maximum shearing stress, and that the dimensions of the reinforcement are such that it may reasonably be approximated by a curved beam. Under these assumptions, an upper bound on the necessary thickness of the reinforcement for any given radius is obtained. Certain practical limitations of the theory are discussed.
Plastic-Rigid Analysis of Long Beams Under Transverse Impact Loading
Authors: Conroy M. F. 
Published: April 2021

Abstract
The object of this paper is to set forth the results of an investigation of the behavior of long beams under transverse, constant-velocity impact loading, when a plastic-rigid type of analysis is adopted. It was expected that such an analysis would be satisfactory for problems involving large strains, and easier to evaluate than the corresponding elastic-plastic solution. Consideration is first given to the case of ideal plasticity. Elastic strains are neglected and the material of the beam is assumed to flow plastically at a constant yield limit. In this case expressions for the bending moment, shear force, curvature and deflection distributions along the beam are obtained analytically for any given impact velocity. The manner in which the solution for a beam having an elastic-ideally plastic bending moment-curvature relationship converges to the plastic-rigid solution, as EI increases, is discussed. Consideration is next given to the case of work-hardening where the material is assumed to obey a plastic-rigid bending moment-curvature relationship consisting of a straight line with nonzero slope. Unfortunately, difficulty arises in finding a solution analytically in this case. However, by considering the solution for a beam having the corresponding elastic-plastic bending moment-curvature relationship and a large EI-value, some speculation as to the probable form of the solution may be made.
Free Vibrations of Constrained Beams
Authors: Lee Winston F. Z. , Saibel Edward 
Published: April 2021

Abstract
A general expression is developed from which the frequency equation for the vibration of a constrained beam with any combination of intermediate elastic or rigid supports, concentrated masses, and sprung masses can be found readily. The method also is extended to the case where the constraint is a continuous elastic foundation or uniformly distributed load of any length. This method requires only the knowledge of the natural frequencies and natural modes of the beam supported at the ends in the same manner as the constrained beam but not subjected to any of the constraints between the ends. The frequency equation is obtained easily and can be solved to any desired degree of approximation for any number of modes of vibration in a quick and simple manner. Numerical examples are given for a beam with one concentrated mass, for a beam with one sprung mass, and a continuous beam with one sprung mass.
A Gated Two-Frequency Two-Mode Method for Piezoelectric Motorization
Authors: Hsu Yu-Hsiang , Chu Tsung-Yu , Lin Zi-Xun , Lee Chih-Kung 
Published: April 2021

Abstract
In this study, we present a new driving method to generate traveling waves in a finite plate for application to piezoelectric motors. Due to resonant modes which dominate the vibration of finite structures, methods to reduce resonant effects such as using an electric sinker or driving at a non-resonant frequency have been reported. To take advantage of natural resonance and to increase driving efficiency, a new method entitled gated two-frequency-two-mode (G-TFTM) was developed. A piezoelectric bimorph of 1.1 g weight with two rectangular actuators was implemented to verify the design concept. One actuator was operated at a first bending mode and the other actuator operated at a second bending mode with a phase difference. The driving signal was gated to generate an intermittent excitation to provide the periodic propulsion. To determine the profile of the induced traveling wave, an analytical solution was derived and a numerical model was used. Using these design tools, we experimentally verified that traveling waves can be generated using a G-TFTM method. A 0.1-g object can be moved at a speed of 3.31 mm/s under the condition of a 70-to-20 voltage ratio and a 137 deg phase difference. The moving direction was found to be reversed by changing the phase to −43 deg. The experimental and numerical data are detailed in this paper to demonstrate the feasibility of this G-TFTM method.
Human-Knowledge-Augmented Gaussian Process Regression for State-of-Health Prediction of Lithium-Ion Batteries With Charging Curves
Authors: Zhou Quan , Wang Chongming , Sun Zeyu , Li Ji , Williams Huw , Xu Hongming 
Published: April 2021

Abstract
Lithium-ion batteries have been widely used in renewable energy storage and electric vehicles, and state-of-health (SoH) prediction is critical for battery safety and reliability. Following the standard SoH prediction routine based on charging curves, a human-knowledge-augmented Gaussian process regression (HAGPR) model is proposed by incorporating two promising artificial intelligence techniques, i.e., the Gaussian process regression (GPR) and the adaptive neural fuzzy inference system (ANFIS). Human knowledge on voltage profile during battery degradation is first modeled with an ANFIS for feature extraction that helps reduce the need for physical testing. Then, the ANFIS is integrated with a GPR model to enable SoH prediction. Using a GPR model as the baseline, a comparison study is conducted to demonstrate the advantage of the proposed HAGPR model. It indicates that the proposed HAGPR model can reduce at least 12% root-mean-square error with 31.8% less battery aging testing compared to the GPR model.