bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method to Measure Prandtl Number and Thermal Conductivity of Fluids
Authors: Eckert E. R. G. , Irvine T. F. 
Published: June 2021

Abstract
A new method is described by which the Prandtl number and indirectly the thermal conductivity of fluids can be measured. The method is based on the fact that a well-established, unique relation exists between the Prandtl number and the recovery factor for laminar high-velocity boundary-layer flow. The test setup is described which has been devised for such measurements, and test results are presented for air at atmospheric pressure and temperatures between 60 and 350 F.
Forced Vibration of a Body on an Elastic Stratum
Authors: Warburton G. B. 
Published: June 2021

Abstract
The paper considers the forced vibration of a body with a circular base resting on a homogeneous elastic stratum of infinite surface area and constant depth. The body is subjected to a vertical disturbing force along the axis of symmetry. After evaluating an integral given by Arnold, Bycroft, and Warburton, curves are given showing the dependence of the resonant frequency on three parameters. Good agreement is obtained between theoretical values of the resonant frequency and experimental values taken from the previous paper.
A Theoretical Criterion for the Fracture of Metals Under Combined Alternating Stresses
Authors: Yokobori Takeo 
Published: June 2021

Abstract
A criterion for the fracture of metals under combined alternating stresses is developed on the basis of the present concepts of dislocations. These concepts are modified by taking into account the stress concentration by the inclusion itself against which dislocations pile up. The agreement is good with the experimental data in the literature.
Stresses and Displacements in an Elastic-Plastic Wedge
Authors: Naghdi P. M. 
Published: June 2021

Abstract
An elastic, perfectly plastic wedge of an incompressible isotropic material in the state of plane strain is considered, where the stress-strain relations of Prandtl-Reuss are employed in the plastic domain. For a wedge (with an included angle β) subjected to a uniform normal pressure on one boundary, the complete solution is obtained which is valid in the range 0 &lt; β &lt; π/2; this latter limitation is due to the character of the initial yield which depends on the magnitude of β. Numerical results for stresses and displacements are given in one case (β = π/4) for various positions of the elastic-plastic boundary.
On the Stress Distribution at the Base of a Stationary Crack
Authors: Williams M. L. 
Published: June 2021

Abstract
In an earlier paper it was suggested that a knowledge of the elastic-stress variation in the neighborhood of an angular corner of an infinite plate would perhaps be of value in analyzing the stress distribution at the base of a V-notch. As a part of a more general study, the specific case of a zero-angle notch, or crack, was carried out to supplement results obtained by other investigators. This paper includes remarks upon the antisymmetric, as well as symmetric, stress distribution, and the circumferential distribution of distortion strain-energy density. For the case of a symmetrical loading about the crack, it is shown that the energy density is not a maximum along the direction of the crack but is one third higher at an angle ± cos−1 (1/3); i.e., approximately ±70 deg. It is shown that at the base of the crack in the direction of its prolongation, the principal stresses are equal, thus tending toward a state of (two-dimensional) hydrostatic tension. As the distance from the point of the crack increases, the distortion strain energy increases, suggesting the possibility of yielding ahead of the crack as well as ±70 deg to the sides. The maximum principal tension stress occurs on ±60 deg rays. For the antisymmetrical stress distribution the distortion strain energy is a relative maximum along the crack and 60 per cent lower ± 85 deg to the sides.
Two-Dimensional, Steady, Cavity Flow About Slender Bodies in Channels of Finite Breadth
Authors: Cohen Hirsh , Gilbert Robert 
Published: June 2021

Abstract
The steady, cavitating flow past slender symmetrical bodies placed in a solid-wall channel is studied by means of the linearized theory of Tulin. The free-boundary condition is linearized and boundary conditions are applied on the line of symmetry of the flow in analogy with thin-air-foil theory. A singular integral equation formulation of the boundary-value problem is obtained and can be solved to yield expressions for cavity length, maximum cavity width, and drag coefficient as functions of the cavitation number and the channel breadth. These expressions are given for an arbitrary body and evaluated for the case of a wedge.
Corrections for the Oscillating-Disk Viscometer
Authors: Kestin J. , Wang H. E. 
Published: June 2021

Abstract
The paper reviews existing theories of the oscillating-disk viscometer and demonstrates their inadequacy. Using the results obtained previously by Kestin and Persen together with an empirical assumption that the edge-correction factor is proportional to the ideal viscous torque pieced together from the infinite-disk and infinite-cylinder solutions, the authors are able to develop working formulas which, in addition to the edge effect, include the effect of wire damping and unequal separation. The effect of a stem is discussed separately and shown to be negligible. Some remarks are made about the decrement-period relationship. The assumptions are compared with experimental results which demonstrate that for a given suspension system the edge-correction factor C depends on the dimensionless ratio x0 = δ/R (δ = √[ν/ω0] is the average boundary-layer thickness and R is the external radius of the disk) in a unique way. This shows that the use of the authors’ equations together with a suitable calibration procedure should lead to reliable values of viscosity.
The Propagation of Compressional Waves in a Dispersive Elastic Rod: Part I—Results From the Theory
Authors: Miklowitz Julius 
Published: June 2021

Abstract
Information on the propagation of compressional waves in a rod, in accord with the Mindlin-Herrmann approximate theory, is presented. The information stems from two sources: (a) A numerical evaluation of a previously derived integral solution, for the problem of a semi-infinite rod subjected to a step axial pressure, and (b) application of Kelvin’s stationary-phase method to the classical problem of the infinite rod subjected initially to an infinite axial pressure at the origin.
The Propagation of Compressional Waves in a Dispersive Elastic Rod: Part II—Experimental Results and Comparison With Theory
Authors: Miklowitz Julius , Nisewanger C. R. 
Published: June 2021

Abstract
Experimental results, obtained by employing an aerodynamic shock tube for rod excitation, are presented. Comparison of these results with the theoretical information presented in Part I is made. It is shown that the Mindlin-Herrmann theory, through its upper mode (radial), offers a good approximate representation of the moderately short waves that predominate at the later times at a random station of the rod. The very short waves of this same radial mode, however, govern the early disturbance, thus precluding the possibility of representing this portion of the disturbance, which the experiment shows to be composed of relatively long waves, by the longitudinal mode of the theory.
Stress Distributions in Rotating Disks Subjected to Creep at Elevated Temperature
Authors: Wahl A. M. 
Published: June 2021

Abstract
Assuming a creep rate proportional to a power function of the stress, curves of stress distribution as a function of the radius have been calculated for several cases of rotating disks subject to steady-state creep at elevated temperature. The disks are assumed to have central holes and to be uniformly loaded at the periphery (to simulate blade loading in turbine disks). It is also postulated that the Tresca (maximum-shear) criterion and the associated flow rule govern. The following cases are treated: (1) Disk of constant temperature and thickness with various ratios of outside to inside diameter and with various values of the exponent n in the assumed power function stress-creep rate relation. (2) Disk of constant temperature and variable thickness, the thickness at the periphery being equal to half that at the hub, for various n-values. (3) Disk with variable temperature such that the creep rate at the outside diameter is ten times that at the inside diameter for the same stress, various n-values being assumed. Limits of radial peripheral loading beyond which the derived stress-distribution curves are not valid are also determined. The results indicate that a considerable nonuniformity in stress distribution under creep conditions may exist, particularly for the lower n-values; thus creep-rupture strengths of such disks for long-time loading conditions may be lower than would be expected if based on average stress values, particularly for materials having limited ductility in long-time creep-rupture tests.
A Type of Flame-Excited Oscillation in a Tube
Authors: Bailey J. J. 
Published: June 2021

Abstract
Propane-air mixtures were burned in an effectively open-ended tube containing a screen flameholder. Two types of instability were observed. Of these, one is described in some detail. A driving mechanism is proposed and examined in the light of Rayleigh’s criterion. Finally, a linear, one-dimensional theory is presented, taking into account both the driving and damping effects in the system. The predictions of this theory are shown to be in good agreement with the experimental results.
A Photoelastic Study of Strain Waves Caused by Cavitation
Authors: Sutton G. W. 
Published: June 2021

Abstract
Ultra-high-speed photoelastic techniques have been applied to a study of the transient stresses and strains in a photoelastic plastic when subject to cavitation. A photocell, used to detect the transient strains, indicated that the time duration of the strains was about 2 microsec. Using an ultra-high-speed motion-picture camera, ultrasonic cavitation bubbles have been photographed collapsing on the surface of a photoelastic specimen, and the resulting strain wave in the solid has been photographed. The dynamic properties of a photoelastic material have been obtained in order to permit quantitative interpretation of the transients. This has indicated that the stresses due to cavitation may be as high as 2 × 105 psi. The photoelastic plastic, CR-39, was found to exhibit strain birefringence, and its strain-optic constant was found to be independent of the rate of loading.
Photothermoelasticity: An Exploratory Study
Authors: Gerard George , Gilbert A. C. 
Published: June 2021

Abstract
This paper summarizes the optical and physical properties of the photoelastic model material Paraplex P-43 over the temperature range from room temperature to −40 F. Descriptions are presented of techniques and equipment developed to obtain the modulus of elasticity, the material fringe value, and the thermal-expansion coefficient as a function of temperature. Experimental investigations were conducted into the plane-stress problems of a disk contracting upon an elastic inclusion and the transient thermal-stress field produced by a temperature differential suddenly applied to the upper edge of a long beam. The data are correlated with theory using the material properties obtained in the calibration phase. Also included are photographic results of an exploratory investigation of the thermal-shock phenomenon produced by the sudden application of a temperature differential upon plastic beams of various length-depth ratios.
A Study of the Propagation of Flexural Waves in Elastic Beams
Authors: Ripperger E. A. , Abramson H. Norman 
Published: June 2021

Abstract
Experimental results for flexural wave propagation in elastic beams of circular cross sections resulting from very sharp impacts are presented. It is noted that a well-defined wave system precedes the main pulse. The experimental results are correlated with theoretical predictions from both the Pochhammer-Chree and Timoshenko theories.
Nodal Patterns of the Free Flexural Vibrations of Stiffened Plates
Authors: Hoppmann W. H. , Magness L. S. 
Published: June 2021

Abstract
With the aid of results from previous research on the vibration of stiffened plates, a study is made of the nodal patterns of a particular plate with orthogonally placed stiffeners. The pertinent theory of vibration of stiffened plates is introduced. Experiments are described. The normal modes of vibration are investigated. Frequencies of flexural vibration are given for theory and experiment. The compounding of modes is illustrated by a single but rather convincing example. The rôle of research concerning normal modes of vibration of stiffened plates is discussed.
Force in the Plane of Two Joined Semi-Infinite Plates
Authors: Frasier J. T. , Rongved Leif 
Published: June 2021

Abstract
The stress due to a force parallel to the plane of two joined semi-infinite plates is obtained from the three-dimensional state of stress produced by a force operative at a point interior to one of two joined semi-infinite elastic solids. The variation in the traction on the interface of a steel and aluminum plate is shown graphically.
Detrital zircon geochronology of modern river sediment in south-central Alaska: Provenance, magmatic, and tectonic insights into the Mesozoic and Cenozoic development of the southern Alaska convergent margin
Authors: Fasulo Cooper R. , Ridgway Kenneth D. 
Published: June 2021

AbstractNew and previously published detrital zircon U-Pb ages from sediment in major rivers of south-central Alaska archive several major episodes of magmatism associated with the tectonic growth of this convergent margin. Analysis of detrital zircons from major trunk rivers of the Tanana, Matanuska-Susitna, and Copper River watersheds (N = 40, n = 4870) documents major &lt;250 Ma age populations that are characteristic of the main phases of Mesozoic and Paleogene magmatism in the region as documented from limited U-Pb ages of igneous rocks. Key points from our detrital record include: (1) Major magmatic episodes occurred at 170, 150, 118, 95, 72, 58, and 36 Ma. The overall pattern of these ages suggests that felsic magmatism was episodic with periodicity ranging between ~14 and 32 m.y. with an average of ~22 m.y. (2) Magmatism in south-central Alaska shows similar age trends with both the Coast Mountains batholith and the along-strike Alaska Peninsula forearc basin strata, demonstrating a spatial and temporal relationship of felsic magmatism along the entire northern Cordilleran margin. (3) Topography and zircon fertility appear to influence the presence and/or absence of detrital zircon populations in individual watersheds. Results from this study indicate that regionally integrated detrital zircon populations from modern trunk rivers are faithful recorders of Mesozoic and Paleogene magmatic events along a convergent margin, but there appears to be a lag time for major rivers to record Neogene and ongoing magmatic events.
Mechanism of the Antioxidant Activity and Structure–Activity Relationship of N-Monosubstituted Amino Acid Derivatives of Fullerene С60
Authors: Volkov V. A. , Voronkov M. V. , Sazhina N. N. , Kurilov D. V. , Vokhmyanina D. V. , Yamskova O. V. , Martirosyan Yu. Ts. , Atroshenko D. L. , Martirosyan L. Yu. , Romanova V. S. 
Published: June 2021

Abstract
The kinetic characteristics, mechanisms of activity, and relationship between the antioxidant activity and the molecular and supramolecular structure of fullerene C60 and some of its N-monosubstituted amino acid derivatives have been studied. The introduction of an amino acid substituent in the C60 fullerene molecule led to an increase in its antiradical activity in the free radical oxidation of a water-soluble target (fluorescein). The mechanism of the antioxidant activity of amino acid derivatives of fullerene is not associated with the hydrogen atom transfer, electron donation, or catalysis of peroxide decomposition. It was demonstrated that the structure of the amino acid substituent does not affect the antiradical properties, which are thus determined only by the effective total surface area of ​​the nanoparticles of the fullerene C60 derivatives and increase when their size decreases. This surface can be characterized as nanowalls on which the radical death occurs. A change in the concentration of the compounds in solution does not lead to a change in the relative antiradical activity and hence in the nanoparticle size. The results of this study are important for understanding the biological activity of this group of compounds.
Trial of aerosolised surfactant for preterm infants with respiratory distress syndrome
Authors: Jardine Luke , Lui Kei , Liley Helen G , Schindler Timothy , Fink James , Asselin Jeanette , Durand David 
Published: June 2021

ObjectiveTo evaluate the safety of an aerosolised surfactant, SF-RI 1, administered via nasal continuous positive airway pressure (nCPAP) and a prototype breath synchronisation device (AeroFact), to preterm infants with respiratory distress syndrome (RDS).DesignMulticentre, open-label, dose-escalation study with historical controls.SettingNewborn intensive care units at Mater Mothers’ Hospital, Brisbane, and Royal Hospital for Women, Sydney, Australia.PatientsInfants 26 weeks through 30 weeks gestation who required nCPAP 6–8 cmH2O and fraction of inspired oxygen (FiO2) <0.30 at <2 hours of age.InterventionsIn part 1, infants received a single dose of 216 mg/kg of aerosolised surfactant. In part 2, infants could receive up to four doses of aerosolised surfactant. Three historical control infants were matched for each enrolled infant.Main outcome measuresTreatment failure was defined as Respiratory Severity Score (FiO2×cmH2O nCPAP) >2.4, nCPAP >8 cmH2O, arterial carbon dioxide >65 mm Hg, pH <7.20 or three severe apnoeas within 6 hours during the first 72 hours of life. Other outcomes included tolerance of the AeroFact treatment and complications of prematurity.Results10 infants were enrolled in part 1 and 21 in part 2 and were compared with 93 historical controls. No safety issues were identified. In part 2, 6 of 21 (29%) AeroFact-treated infants compared with 30 of 63 (48%) control infants met failure criteria. Kaplan-Meier analysis of patients in part 2 showed a trend towards decreased rate of study failure in the AeroFact-treated infants compared with historical controls (p=0.10).ConclusionThe AeroFact system can safely deliver aerosolised surfactant to preterm infants with RDS who are on nCPAP.Trial registration numberACTRN12617001458325.
Triage and resuscitation tools for low and middle income countries: how to catch the killer?
Authors: Santhanam Indumathy , Moodley Prinetha , Jayaraman Balaji , Yock-Corrales Adriana , Cheema Baljit , Craig Simon , Jahn Haiko Kurt 
Published: June 2021

Under-5 mortality rates in low and middle-income countries (LMIC) remain high. One major contributing factor is the failure to recognise critically unwell children when they first present to hospital. This leads to delayed or inadequate resuscitation and an increased risk of death.Triage is a key skill in this setting to sort the queue and prioritise patients, even when staff and equipment are scarce. In LMIC, children generally present late in their illness and often have progressed to some degree of multiorgan dysfunction.Following triage, a structured systematic primary survey is critical to ensure the detection of subtle signs of multiorgan dysfunction. Repeated physiological assessments of the child guide subsequent resuscitation management decisions, which depend somewhat on the resources available.It is possible to achieve significant improvements in survival of critically unwell children presenting for emergency care in the resource-limited setting. The three key steps in the patient’s journey that we can influence in emergency care are triage, primary survey and initial stabilisation. Resources that address these steps have been developed for all settings. However, these resources were developed in a specific clinical context, and must therefore be adapted to local structures and processes. A systematic approach to triage and resuscitation saves lives.
Caregiver-mediated interventions to support self-regulation among infants and young children (0–5 years): a protocol for a realist review
Authors: Finlay-Jones Amy , Ang Jetro Emanel , Bennett Elaine , Downs Jenny , Kendall Sally , Kottampally Keerthi , Krogh-Jespersen Sheila , Lim Yi Huey , MacNeill Leigha A. , Mancini Vincent , Marriott Rhonda , Milroy Helen , Robinson Monique , Smith Justin D , Wakschlag Lauren S , Ohan Jeneva L 
Published: June 2021

IntroductionSelf-regulation is a modifiable protective factor for lifespan mental and physical health outcomes. Early caregiver-mediated interventions to promote infant and child regulatory outcomes prevent long-term developmental, emotional and behavioural difficulties and improve outcomes such as school readiness, educational achievement and economic success. To harness the population health promise of these programmes, there is a need for more nuanced understanding of the impact of these interventions. The aim of this realist review is to understand how, why, under which circumstances and for whom, early caregiver-mediated interventions improve infant and child self-regulation. The research questions guiding this review were based on consultation with families and community organisations that provide early childhood and family services.Methods and analysisRealist reviews take a theory-driven and iterative approach to evidence synthesis, structured around continuous refinement of a programme theory. Programme theories specify context-mechanism-outcome configurations to explain what works, for whom, under which circumstances and how. Our initial programme theory is based on prior work in this field and will be refined through the review process. A working group, comprising service users, community organisation representatives, representatives from specific populations, clinicians and review team members will guide the evidence synthesis and interpretation, as well as the development and dissemination of recommendations based on the findings of the review. The review will involve searching: (i) electronic databases, (ii) connected papers, articles and citations and (iii) grey literature. Decisions to include evidence will be guided by judgements about their contribution to the programme theory and will be made by the research team, with input from the working group. Evidence synthesis will be reported using the Realist and MEta-narrative Evidence Synthesis: Evolving Standards guidelines.Ethics and disseminationEthical approval is not required as this is a review. Findings will be disseminated to our working group and through peer-reviewed publications and conference presentations.Review registration numberThe protocol is registered with Open Science Frameworkhttps://osf.io/5ce2z/registrations.