Miracle-dz/UniFAR-FTUs huggingface dataset:
Oscillation properties of forced third-order differential equations

have been studied in several works, some which include the investigations of Burton and Grimmer [1], Keener [3] and Hammett [2]. Hammett, in particular, has given conditions under which the nonoscillatory solutions of (3) tend to zero. The main purpose of this work is to carry out a similar study for (2). The techniques used herein are patterned after those in [6] in which Singh concentrated on equations with retarded arguments. Recall that a solution of (1) or (2) is called oscillatory if it has arbitrarily large zeros and nonoscillatory otherwise. A solution y is termed quickly oscillatory if there exists an increasing sequence of zeros of y, {f,-}^ with the property that lim,_+00(rl+1 — /,•) = 0. The concept of quickly oscillatory solutions is also considered in other works, see [4] and [7].
A simulation study of east-west IMF effects on the magnetosphere

The effect of adding a By magnetic component to a solar wind already carrying a Bz magnetic component is studied using 3-D MHD computer simulations. It is found that the tail structure and the Bx lobe fields are rotated and become asymmetric. In addition a By component is generated in the neutral sheet. These results are found to correlate with observational data.
Frequency-dependent dynamics of domain walls in yttrium iron garnet

An analysis of the frequency-dependent dynamics of domain walls in polycrystalline yttrium iron garnet samples is presented. This analysis has been carried out, on the one hand, considering the theoretical aspects relatedto the numerical solving of the motion of a Bloch wall using harmonic fields. On the other hand, we have measured the magnetic aftereffect phenomena by using the technique known as magnetic disaccommodation. The experimental results change drastically with the measuring frequency for all the samples, showing the presence of a relaxing process related to the electronic hopping between ferric and ferrous ions and magnetic accommodation processes. The agreement between these results and the theoretical model analyzed has led us to interpret these phenomena in terms of a time-dependent resonance mechanism when an induced anisotropy relaxing process takes place.
Bipolar model for traveling-wave induced nonequilibrium double-layer streaming in insulating liquids

A model is proposed for the time evolution of ion concentrations in a thin charge layer near an interface between an insulating solid and a semi‐insulating bipolar liquid, subjected to an applied electric field. Given the specific case of a traveling‐wave applied field of peak magnitude E0 and planar geometry, solutions for the charge density and electric field in the layer are used to calculate the time‐average stress moment and, hence, the pumping velocity of the liquid. Analytic solutions, valid in the regimes of small applied field magnitude (E0LD/Vt≪1, where L0 and Vt are the Debye length and thermal voltage, respectively) or frequency (ωe/σ≪1, ω the angular frequency and e and σ the permittivity and equilibrium conductivity, respectively), predict charge layers with a characteristic dimension of the Debye length and fluid pumping in the direction of propagation of the traveling wave (forward). Numerical solutions, in the regime of large magnitude fields with ωe/σ∼1, predict either forward or backwar.
Compressive Strength and Microstructure of 0–3 Lead Zirconate Titanate Ceramic-Portland Cement Composites

Lead zirconate titanate (PZT)-Portland cement (PC) composites have been reported to have good potential for use in smart structures. In this work, PZT-PC composites containing 40%, 50% and 60% of PZT by volume were produced and their mechanical and hydration properties were investigated. Compressive strengths of those typically used in normal concrete were found for all PZT-PC composites, with measured values of 41.5–45.0 MPa. Hydration products of Portland cement detected by thermal analysis were calcium silicate hydrates (the main cement hydration product), calcium hydroxide and ettringite. Furthermore, calcium silicate hydrates and ettringite can also be observed surrounding the PZT grains in the SEM micrograph.
Itinerant-electron metamagnetic transition and large magnetovolume effects in La(Fe x Si 1-x ) 13 compounds

Magnetic properties and magnetovolume effects have been investigated for itinerant-electron metamagnetic La(Fe x Si 1 - x ) 1 3 compounds, At the Curie temperature T C 1 , a first-order magnetic phase transition takes place in the concentration range 0.86≤x≤0.88. With increasing Fe concentration, the Curie temperature decreases and the critical temperature of the itinerant-electron metamagnetic (IEM) transition increases, accompanied by a more sharp IEM transition. For the compound with x = 0.88, a large volume change of about 1% follows the thermal induced transition at T C 1 . The value of T C 1 is significantly decreased by applying hydrostatic pressure, whereas the pressure dependence of the spontaneous magnetization is relatively small. These results are explained by the negative mode-mode coupling among spin fluctuations.
A global approach to generalized function algebras

We consider distributions on a closed compact manifold as maps on smoothing operators to smooth functions. For any subgroup of the diffeomorphism group, we produce a full-type algebra of generalized functions and an equivariant embedding of distributions into this algebra. As examples, we consider groups of Riemannian isometries and the symplectic group.
Topological results in combinatorics.

Soit Δ un complexe simplicial fini d'ensemble sommet V={x 0 ,. ,x n }. Soit h(Δ) la dimension homologique de K(Δ), ou K est un corps. On demontre que le nombre n-h(Δ)=dim Δ est un invariant topologique de |Δ| l'espace topologique soustendant Δ
Multifactorial study of the relationship between fear of childbirth and mode of delivery

Objective. This study investigated the relationship between fear of childbirth (FOC) and mode of delivery and proposed a cut-off value of FOC for an unselected Turkish pregnant population. Materials and Methods. This cross-sectional study was conducted between March 2019 and February 2020 at Kirsehir Ahi Evran University Obstetrics and Gynecology Polyclinic. The Wijma Delivery Expectancy (WDEQ-A) Scale and General Information Form were used for data collection. Results. Social-media effect, concern for disorder in baby, education level, and fear of vaginal bleeding were significant risk factors for the study groups. A new cut-off value of FOC was proposed based on the distribution of FOC scores as 69 (fourth quartile) for an unselected Turkish pregnant population. Conclusions. Training programs regarding delivery and pregnancy processes were recommended to be organized to reduce FOC. Moreover, the newly proposed cut-off value of FOC was recommended to be utilized in clinics.
Prospects for Diffractive and Forward Physics at the LHC

The CMS and TOTEM experiments intend to carry out a joint diffractive/forward physics program with an unprecedented rapidity coverage. The present document outlines some aspects of such a physics program, which spans from the investigation of the low-x structure of the proton to the diffractive production of a SM or MSSM Higgs boson.
Pressure‐induced alpha‐omega transformation in titanium: Features of the kinetics data

The increase in the electrical resistance of the specimen, associated with the α→ω transformation in Ti, has been used to obtain the fraction ζ of the ω phase as a function of time under isobaric–isothermal conditions in the pressure range 4–9 GPa and at 300±3 K. In the entire pressure range ζ–t data fit an equation of the form: ζ=1−exp−(t/τ)n, where τ and n are constants at a given pressure. The results indicate that τ decreases rapidly and n slightly with increase in pressure. An analysis of τ–p data shows that (i) the activation free energy for the total process is very high at low pressures and decreases rapidly with increasing pressure, and (ii) the activation volume in the 6–9 GPa range is −4.3 cm3 mol−1. The activation enthalpy has been obtained by measuring τ at different temperatures, and the average value in the pressure range 5–8 GPa is 12±0.5 kCal mol−1.
Pressure-driven flow of a thin viscous sheet

Systematic asymptotic expansions are used to find the leading-order equations for the pressure-driven flow of a thin sheet of viscous fluid. Assuming the fluid geometry to be slender with non-negligible curvatures, the Navier–Stokes equations with appropriate free-surface conditions are simplified to give a ‘shell-theory’ model. The fluid geometry is not known in advance and a time-dependent coordinate frame has to be employed. The effects of surface tension, gravity and inertia can also be incorporated in the model.
Coherence and Reynolds stresses in the turbulent wake behind a curved circular cylinder†

The turbulent wake behind a curved circular cylinder is investigated based on data obtained from a direct numerical simulation. Here, emphasis is placed in the assessment of two approaches for simplified modelling: reduced-order modelling (ROM) and Reynolds-averaged Navier–Stokes equations. To this end, the instantaneous vortical structures, the proper orthogonal decomposition (POD) of the flow, and relevant Reynolds stress components have been analysed. The results show that despite the complexity of the instantaneous vortical structures, the wake dynamics are governed by the quasi-periodic shedding of primary vortices. Between 24% and 50% of the kinetic energy in the POD is captured by the two most energetic modes, and about 200 modes are needed to capture 90% of the kinetic energy. These findings suggest that, as long as the large-scale structures of the von Kármán vortex shedding are concerned, the present case can be approached by ROM; but a detailed representation of the flow dynamics without an eddy viscosity model that accounts for the unresolved turbulent fluctuations would require a large amount of degrees of freedom. Concerning the Reynolds stresses, their magnitude varies considerably depending on the depth at which they have been sampled. This dependence is related to the strength of the vortex shedding, and the intensity of the secondary flows induced by the curvature of the cylinder. As a consequence of the combination of these two effects, the correlation between streamwise and vertical velocity fluctuations is highest in the wake behind the midspan of the curved cylinder, and the correlation between cross-flow and vertical velocity fluctuations reaches large values in the lower wake.
PRESENT-DAY MASS FUNCTION OF SIX SMALL MAGELLANIC CLOUD INTERMEDIATE-AGE AND OLD STAR CLUSTERS

We determined the present-day mass functions (PDMFs) of the five intermediate-age star clusters Lindsay 1, Kron 3, NGC 339, NGC 416, and Lindsay 38 and the old star cluster NGC 121 in the Small Magellanic Cloud (SMC) based on observations with the Hubble Space Telescope Advanced Camera for Surveys. The global PDMFs are well matched by Salpeter-like power laws from their main-sequence turnoffs to ∼0.6 M☉ with a power-law exponent α ranging from 1.51 ± 0.11 (Lindsay 1) to 2.29 ± 0.15 (NGC 339). We derive total stellar masses of ∼105 M☉, except for Lindsay 38, whose mass is of the order of ∼104 M☉. Differences between the PDMFs most likely reflect the varying stages of dynamical evolution of the clusters. These SMC clusters do not follow the α versus concentration parameter c correlation as found for Galactic globular clusters of similar mass. This might be an age effect or due to their location in a galaxy where bulge and disk crossings do not play a role. No correlation is found between α and the cluster core and tidal radii (rc and rt, respectively), the half-light radii rh, age, central surface brightness, metallicity, and galactocentric radius rgc. All six clusters mass-segregated to different degrees. The two clusters Lindsay 1 and Kron 3 barely show signs for mass segregation, but have low-mass star deficient global PDMFs and might be the remnants of star clusters whose outer parts were stripped. A trend exists between the degree of mass segregation and the ratio age/relaxation time tr, h, which indicates the stage of dynamical evolution for a cluster. Our data thus suggest that the SMC clusters in the present sample had a range of initial densities and presumably different amounts of mass loss that led to different rates of dynamical evolution. The clusters’ positions in the rh, m/rt versus r0/rh, m plane imply that all of the clusters are tidally filled. Our SMC clusters with projected distances larger than 3 kpc from the SMC center should have Jacobi radii significantly larger than their observed King tidal radii. The clusters also have higher mean densities than the estimated central density of the SMC. It is possible that these clusters formed in a denser overall environment of the younger SMC, or that the cluster structures were unusually strongly influenced by encounters with giant molecular clouds.
The residual streamer channel: Return strokes and secondary streamers

The streamer and return stroke concepts in positive corona breakdown are reviewed, and examined critically for the case of short (<5 cm) gaps in ambient air. It is shown that return strokes normally should not be observed, but that return streamers may occur in longer or highly overvolted streamer channels. A new physical picture is presented of the secondary streamer, as one or several high field domains formed by Douglas‐Hamilton–Mani‐type attachment instability of the residual channel created by the passage of the primary streamer. In this way, both the erratic origin and development of the secondary streamer in air are easily explained, as well as the fact that spark breakdown follows if and when the secondary streamer fills the complete residual channel length. Further, it follows that the secondary streamer is not the cause of breakdown, but only a secondary side effect.
Coefficients of Determination for Multiple Logistic Regression Analysis

Abstract Coefficients of determination for continuous predicted values (R 2 analogs) in logistic regression are examined for their conceptual and mathematical similarity to the familiar R 2 statistic from ordinary least squares regression, and compared to coefficients of determination for discrete predicted values (indexes of predictive efficiency). An example motivated by substantive concerns and using empirical data from a national household probability sample is presented to illustrate the behavior of the different coefficients of determination in the evaluation of models including dependent variables with different base rates—that is, different proportions of cases or observations with “positive” outcomes. One R 2 analog appears to be preferable to the others both in terms of conceptual similarity to the ordinary least squares coefficient of determination, and in terms of its relative independence from the base rate. In addition, base rate should also be considered when selecting an index of predictive efficiency. As expected, the conclusions based on R 2 analogs are not necessarily consistent with conclusions based on predictive efficiency, with respect to which of several outcomes is better predicted by a given model.
A PROCEDURE FOR COMPUTING THE K BEST SOLUTIONS TO DISCRETE OPTIMIZATION PROBLEMS AND ITS APPLICATION TO THE SHORTEST PATH PROBLEM

A general procedure is presented for computing the best, 2nd best,. , Kth best solutions to a given discrete optimization problem. If the number of computational steps required to find an optimal solution to a problem with n(0, 1) variables is c(n), then the amount of computation required to obtain the if best solutions is O(K nc (n)). The procedure specializes to published procedures of Murty and of Yen for the assignment problem and the shortest path problem, respectively. A method is presented for reducing the required amount of storage by a factor of n, compared with the algorithms of Murty and of Yen. It is shown how the K shortest (loopless) paths in an n-node network with positive and negative arcs can be computed with an amount of computation which is O(Kn 3 ). This represents an improvement by a factor of n, compared with Yen's algorithm.
Vacillations in a Coupled Ocean–Atmosphere Model

Abstract Results are presented from a 35-year integration of a coupled ocean-atmosphere model. Both ocean and atmosphere are two-level, nonlinear primitive equations models. The global atmospheric model is forced by a steady, zonally symmetric Newtonian heating. The ocean model is solved in a rectangular tropical basin. Heat fluxes between ocean and atmosphere are linear in air-sea temperature differences, and the interfacial stress is proportional to lower-level atmospheric winds. The coupled models produce ENSO-like variability on time scales of 3 to 5 years. Since there is no external time-dependent forcing, these are self-sustained vacillations of the nonlinear system. It is argued that the energetics of the vacillations is that of unstable coupled modes and that the time scale is crucially dependent on the effects of ocean waves propagating in a closed basin.
A Study of Financial Deepening, Capital Accumulation and Macroeconomic Variables in Nigeria

Low capital accumulation or savings due to financial shallowness instead of financial deepening is a worrisome situation that needs to be addressed. This is because low capital accumulation will lead to low investment and this would hinder the achievement of one of the Sustainable Development Goals of economic growth and full employment. Data, which were relevant to variables of study like financial deepening and total savings (which was used to capture capital accumulation), and spanning 48 years from 1970 to 2018 were gathered from secondary sources and analyzed using the ARDL model. The result proved that savings accumulation has a long-term positive and significant impact on financial deepening. The paper recommends amongst others that banking habits should be encouraged to every Nigerian so as to increase total savings and hence, capital accumulation.
⟨001⟩ textured polycrystalline current-perpendicular-to-plane pseudo spin-valves using Co2Fe(Ga0.5Ge0.5) Heusler alloy

The orientation dependence of current-perpendicular-to-plane giant-magnetoresistance (CPP-GMR) was investigated by fabricating ⟨001⟩ textured polycrystalline pseudo spin valves (PSVs) with Co2Fe(Ga0.5Ge0.5) (CFGG) Heusler alloy ferromagnetic layers and a Ag spacer. The PSV with 10 nm CFGG annealed at 400 °C exhibited the resistance-change area product (ΔRA) of 5.8 mΩ (MR ratio of 16%), the largest value reported for polycrystalline CPP-(P)SVs. The ⟨001⟩ textured CFGG PSV outperforms the ⟨011⟩ textured CFGG PSV possibly due to the reduced lattice mismatch or improved band matching at the CFGG/Ag interface.
Numerical simulations of xylophones. I. Time-domain modeling of the vibrating bars

A time-domain modeling of xylophone bars excited by the blow of a mallet is presented. The flexural vibrations of the bar, with nonuniform cross section, are modeled by a one-dimensional Euler–Bernoulli equation, modified by the addition of two damping terms for the modeling of losses and a restoring force for the modeling of the stiffness of the suspending cord. The action of the mallet against the bar is described by Hertz’s law of contact for linear elastic bodies. This action appears as a force density term on the right-hand side of the bending wave equation. The model is completed by the equation of motion for the mallet, and by free–free boundary conditions for the bar. The bending wave equation of the bar is put into a numerical form by means of an implicit finite-difference scheme, which ensures a sufficient spatial resolution for an accurate tuning of the bar. The geometrical, elastic, and damping parameters of the model are derived from experiments carried out on actual xylophones and mallets. T.
Hypercyclic and chaotic integrated C-cosine functions

The main purpose of the paper is to display the main structural properties of hypercyclic and chaotic integrated C-cosine functions. The notions of hypercyclicity, mixing and chaoticity of an α-times integrated C-cosine function (α≥0) are defined by using distributional techniques. We provide several examples which justify our abstract theoretical approach. [Projekat Ministarstva nauke Republike Srbije, br. 144016]
Quasilinearization method and its verification on exactly solvable models in quantum mechanics

The proof of the convergence of the quasilinearization method of Bellman and Kalaba, whose origin lies in the theory of linear programming, is extended to large and infinite domains and to singular functionals in order to enable the application of the method to physical problems. This powerful method approximates solution of nonlinear differential equations by treating the nonlinear terms as a perturbation about the linear ones, and is not based, unlike perturbation theories, on existence of some kind of small parameter. The general properties of the method, particularly its uniform and quadratic convergence, which often also is monotonic, are analyzed and verified on exactly solvable models in quantum mechanics. Namely, application of the method to scattering length calculations in the variable phase method shows that each approximation of the method sums many orders of the perturbation theory and that the method reproduces properly the singular structure of the exact solutions. The method provides final.
Observation of vortices in metal‐ and oxide‐superconductors using electron waves

Magnetic vortices in superconductors were directly and dynamically observed using electron waves; magnetic lines of force of vortices were measured by holographic interference microscopy and the dynamics of vortices were observed by Lorentz microscopy. The interaction between vortices and defects in superconductors was observed.
Asymptotic equivalence and summability

This paper is a study of the relatioship. between the asymptotic equivalence of two sequences (limnxn/yn=1) and three variatious of this equivalence for a sequence-to-sequence transformation A, the three variations are give by the ratios RmAx/RmAy. SmAx/SmAy, And μmAx/μmAy, where RmAz:=∑n≥m|(Az)n|, SmAz:=∑n≤m|(Az)n|, and μmAz:=supn≥m|(Az)n|.
Asymptotically optimal induced decompositions

Solving a problem raised by Bondy and Szwarcfiter [J. Graph Theory, 72 (2013), 462-477] we prove that if the edge set of a graph G of order n can be decomposed into edge-disjoint induced copies of the path P4 or of the paw K4−P3, then the complement of G has at least cn3/2 edges. This lower bound is tight apart from the actual value of c, and completes the determination of asymptotic growth for the graphs with at most four vertices. More generally the lower bound cn3/2 holds for any graph without isolated vertices which is not a complete multipartite graph; but a linear upper bound is valid for any complete tripartite graph.