Miracle-dz/UniFAR-FTUs huggingface dataset:
Bounds on Two-Phase Frictional Pressure Gradient and Void Fraction in Circular Pipes

Simple rules are developed for obtaining rational bounds for two-phase frictional pressure gradient and void fraction in circular pipes. The bounds are based on turbulent-turbulent flow assumption. Both the lower and upper bounds for frictional pressure gradient are based on the separate cylinders formulation. For frictional pressure gradient, the lower bound is based on the separate cylinders formulation that uses the Blasius equation to represent the Fanning friction factor while the upper bound is based on the separate cylinders equation that represents well the Lockhart-Martinelli correlation for turbulent-turbulent flow. For void fraction, the lower bound is based on the separate cylinders formulation that uses the Blasius equation to predict the Fanning friction factor while the upper bound is based on the Butterworth relationship that represents well the Lockhart-Martinelli correlation. These two bounds are reversed in the case of liquid fraction (1-α). For frictional pressure gradient, the model is verified using published experimental data of two-phase frictional pressure gradient versus mass flux at constant mass quality. The published data include different working fluids such as R-12, R-22, and Argon at different mass qualities, different pipe diameters, and different saturation temperatures. The bounds models are also presented in a dimensionless form as two-phase frictional multiplier (ϕ l and ϕ g ) versus Lockhart-Martinelli parameter (X) for different working fluids such as R-12, R-22, and air-water and steam mixtures. For void fraction, the bounds models are verified using published experimental data of void fraction versus mass quality at constant mass flow rate. The published data include different working fluids such as steam, R-12, R-22, and R-410A at different pipe diameters, different pressures, and different mass flow rates. It is shown that the published data can be well bounded for a wide range of mass fluxes, mass qualities, pipe diameters, and saturation temperatures.
Planar point sets with a small number of empty convex polygons

A subset A of a finite set P of points in the plane is called an empty polygon, if each point of A is a vertex of the convex hull of A and the convex hull of A contains no other points of P. We construct a set of n points in general position in the plane with only ˜1.62n2 empty triangles, ˜1.94n2 empty quadrilaterals, ˜1.02n2 empty pentagons, and ˜0.2n2 empty hexagons.
Response of Hemispherical Foundation Embedded in Half-Space

The dynamic impedance functions for a rigid hemispherical foundation embedded in a uniform viscoelastic half‐space are obtained by an integral equation approach. Numerical values for the vertical, torsional, horizontal, coupling, and rocking impedance functions for a wide range of frequencies are presented. Comparisons with results obtained by other methods, including finite element models, wave function expansions and other boundary integral formulations, are discussed.
Discontinuous deformation analysis with second‐order finite element meshed block

The discontinuous deformation analysis (DDA) with second‐order displacement functions was derived based on six‐node triangular mesh in order to satisfy the requirement for the accurate calculations in practical applications. The matrices of equilibrium equations for the second‐order DDA were given in detail for program coding. By close comparison with widely used finite element method and closed form solutions, the advantages of the modified DDA were illustrated. The program coding was carried out in C++ environment and the new code applied to three examples with known analytical solutions. A very good agreement was achieved between the analytical and numerical results produced by the modified DDA code. Copyright © 2006 John Wiley & Sons, Ltd.
Itinerant metamagnetism in TiBe2

Résumé. 2014 On discute les mesures de Monod, Felner, Chouteau et Shaltiel [1] de l’aimantation du composé défini TiBe2 sous champs intenses en termes d’une transition métamagnétique sous champs de 5 T environ. Abstract. 2014 The high field magnetization data of Monod, Felner, Chouteau and Shaltiel [1] on TiBe2 are discussed in terms of a metamagnetic transition in fields about 5 T.
A critical study of the Hopkinson pressure bar

The first part of this paper (§§ 1 to 9) contains a description of an electrical method for measuring the relation between pressure and time in experiments on high pressures of short duration. As in the method devised by Hopkinson, the pressure is applied normally to one end of a cylindrical steel bar, producing a stress pulse which gives rise to radial and longitudinal displacements in the bar. The radial displacement, or the longitudinal displacement at the end of the bar remote from the applied pressure, is used to produce a change in the capacity of a suitable condenser unit which is charged to a high potential and connected through a feed circuit and an amplifier to a double-beam cathode-ray oscillograph. The change in capacity of the condenser unit gives rise to a vertical deflexion of one of the beams of the oscillograph, the other beam being used for time-marking. At the appropriate instant, the two beams are traversed rapidly in a horizontal direction across the screen by a sweep circuit triggered by a switch on the pressure bar. By photographing the traces on the screen, an oscillogram , giving the variation with time of the displacement in the bar, is obtained, and from this record the variation of the applied pressure with time can be deduced. The second part of the paper (§§ 10 to 12) begins with a theoretical discussion of the propagation of extensional stress waves and pulses in a bar, using the exact equations due to Pochhammer and to Chree (§ 11), and also a less accurate wave equation due apparently to Love (§ 12). These investigations show that, owing to dispersion, a stress pulse is modified in its passage down the bar, the shorter waves lagging behind the longer ones. The theory provides a satisfactory explanation of certain features of the experimental results which are incompatible with elementary theory. It is found, for example, by the theory of group velocities, that a pulse whose initial duration is very short, becomes extended as it travels along the bar, its duration at distance x cm . from the origin being about 3.3x /isec. In the early stages of the disturbance, extending for the first 1.4x /tsec. , only one dominant group exists; the later portion, extending over 1.9x sec. , is com posed o f two dominant groups which give the characteristic pattern of two superposed oscillations. These conclusions are confirmed by experiment. The theory is used to discuss the errors in the experiments caused by the pressure bar itself, and it is shown that bars about 2 ft. long and 1 in. and 0.5 in. diameter can be used to measure pressures which last for about 20 and 10 /isec. respectively with an accuracy of about 2 to 3 % . T his was confirmed by experiments with bullet impacts and detonation waves in gaseous mixtures, in which the measured values of the pressure could be checked by calculation.
Semiparametric Estimation Methods for Panel Count Data Using Monotone B-Splines

We study semiparametric likelihood-based methods for panel count data with proportional mean model E[ℕ(t)|Z]=Λ0(t)exp(β0TZ), where Z is a vector of covariates and Λ0(t) is the baseline mean function. We propose to estimate Λ0(t) and β0 jointly with Λ0(t) approximated by monotone B-splines and to compute the estimators using generalized Rosen algorithm proposed by Jamshidian (2004). We show that the proposed spline-based likelihood estimators of Λ0(t) are consistent with a possibly better than n1/3 convergence rate if Λ0(t) is sufficiently smooth. The normality of the estimators of β0 is also established. Comparisons between the proposed estimators and their alternatives studied in Wellner and Zhang (2007) are made through simulations studies, regarding their finite sample performance and computational complexity. A real example from a bladder tumor clinical trial is used to illustrate the methods.
Numerical modelling of Coulomb-driven convection in insulating liquids

Electroconvection in a layer of liquid subjected to unipolar injection is characterized by two stability criteria, a linear and a nonlinear one, with an associated hysteresis loop. Experimentally it is found that the velocity field fluctuates around its mean value. A temporal analysis of the measured current, which is directly related to the velocity, revealed the existence of a well-defined frequency correlated to the mean rotation time of a fluid particle in the convective cell, thus indicating that these fluctuations are not stochastic but related to the intrinsic dynamics of the system. Here a method of superparticles is used to solve the problem of the non-stationary electroconvection of the liquid. A good agreement between theoretical and experimental results is obtained.
Riemannian manifolds whose curvature operator R(X, Y) has constant eigenvalues

A Riemannian manifold Mn is called IP, if, at every point x ∈ Mn, the eigenvalues of its skew-symmetric curvature operator R(X, Y) are the same, for every pair of orthonormal vectors X, Y ∈ TxMn. In [5, 6, 12] it was shown that for all n ≥ 4, except n = 7, an IP manifold either has constant curvature, or is a warped product, with some specific function, of an interval and a space of constant curvature. We prove that the same result is still valid in the last remaining case n = 7, and also study 3-dimensional IP manifolds.
Spline solutions of linear sixth-order boundary-value problems

Linear, sixth-order boundary-value problems (special case) are solved, using polynomial splines of degree six. The spline function values at the midknots of the interpolation interval, and the corresponding values of the even-order derivatives are related through consistency relations. The algorithm developed approximates the solutions, and their higher-order derivatives, of differential equations. Two numerical illustrations are given to show the practical usefulness of the algorithm developed. It is observed that this algorithm is second-order convergent.
Theoretical and experimental investigation of rhodamine B-doped polymer optical fiber amplifiers

High-power (620 W) and high-gain (28 dB) amplification was achieved by a rhodamine B (RB)-doped GI polymer-optical fiber amplifier (POFA) with a l-m length. A theoretical analysis of the amplification in the RE-doped GI POFA was carried out using the rate equation for the fast three level system. The calculated gain behaviour reasonably fit the experimental data. The possibility of higher power (more than 620 W) and higher gain (more than 28 dB) amplification covering a wide range in the visible region is shown from the calculation. Absorption and emission cross sections of RE in poly(methyl methacrylate) bulk were determined and used in the calculation. The values of the cross sections (/spl sigma//sub a/ /sub max/=3.4/spl middot/10/sup -20/m/sup 2/,/spl sigma//sub e/ /sub max/=3.4/spl middot/10/sup -20/ m/sup 2/) were approximately 10,000 times larger than those of Er/sup 3+/ in GeO/sub 2/-SiO/sub 2/ glass.
Electron-impact broadening parameters for Be II, Sr II, and Ba II spectral lines

Aims. We present results of the electron-impact broadening parameters (i.e., widths and shifts) of spectral lines in singly ionized Be II, Sr II, and Ba II ions, calculated by using our relativistic quantum mechanical methods. Methods. In these calculations, Dirac R-matrix methods were used to solve (N + 1)electron colliding systems to obtain the required scattering matrices. The dimensionless collision strength Ω(e) is calculated as a function of incident electron energies e. Results. The present line-broadening parameters are required for future spectral analysis by means of state-of-the-art nonlocal thermodynamic equilibrium atmospheres, which is now hampered largely by the paucity of reliable atomic and accurate line-broadening data tables. Our results for the spectral line-broadening parameters in the case of three ions obtained for a set of electron temperatures at an electron density 10 cm−3 show very good agreement with other theoretical calculations, and are much closer to the available experimental measurements.
Output feedback transient stabilization and voltage regulation of synchronous generators

In this brief note, we consider the transient stabilization and voltage regulation problem for a synchronous generator connected to an infinite bus. We show how a much simpler output feedback controller, compared with previous results, can be obtained if a different stability analysis is carried out: a suitable change of coordinates is performed so that advantageous triangularity properties of the regulation error dynamics are highlighted. A novel first order estimator for the uncertain mechanical input power is designed: it is the only adaptation scheme used by the controller. The innovative crucial step in the presented control design relies on relaxing the constraint imposed by the typically (previously) adopted back‐stepping techniques and constituted by the required availability of the regulation/tracking error variables: the converging estimate of the mechanical input power directly becomes the reference value for the electrical power and allows for the straightforward computation of the uncertain power angle constant value guaranteeing voltage regulation at steady state. Copyright © 2011 John Wiley & Sons, Ltd.
Resolution of the Filaments in the Supernova Remnant IC 443

The visible filaments in IC 443 have been resolved at both radio and optical wavelengths. They appear to have coextensive widths of approximately 4.4 arcsec or about 10 to the 17th cm if the SNR lies at the generally adopted distance of 1.5 kpc. The observations are consistent with a picture in which the filaments are cooling and evaporating interstellar clumps which have been overrun by the expanding supernova blast wave. 17 refs.
ESTIMATION OF THE CONCENTRATION PARAMETERS OF THE FISHER MATRIX DISTRIBUTION ON 50(3) AND THE BINGHAM DISTRIBUTION ON Sq, q≥ 2

Summary Two procedures are considered for estimating the concentration parameters of the Fisher matrix distribution for rotations or orientations in three dimensions. The first is maximum likelihood. The use of a convenient 1-dimensional integral representation of the normalising constant, which greatly simplifies the computation, is suggested. The second approach exploits the equivalence of the Fisher distribution for rotations in three dimensions, and the Bingham distribution for axes in four dimensions. We describe a pseudo likelihood procedure which works for the Bingham distribution in any dimension. This alternative approach does not require numerical integration. Results on the asymptotic efficiency of the pseudo likelihood estimator relative to the maximum likelihood estimator are given, and the two estimators are compared in the analysis of a well-known vectorcardiography dataset.
Relativity, quantum physics and philosophy in the upper secondary curriculum: challenges, opportunities and proposed approaches

In this article, we discuss how quantum physics and relativity can be taught in upper secondary school, in ways that promote conceptual understanding and philosophical reflections. We present the ReleQuant project, in which web-based teaching modules have been developed. The modules address competence aims in the Norwegian national curriculum for physics (final year of upper secondary education), which is unique in that it includes general relativity, entangled photons and the epistemological consequences of modern physics. These topics, with their high demands on students’ understanding of abstract and counter-intuitive concepts and principles, are challenging for teachers to teach and for students to learn. However, they also provide opportunities to present modern physics in innovative ways that students may find motivating and relevant both in terms of modern technological applications and in terms of contributions to students’ intellectual development. Beginning with these challenges and opportunities, we briefly present previous research and theoretical perspectives with relevance to student learning and motivation in modern physics. Based on this, we outline the ReleQuant teaching approach, where students use written and oral language and a collaborative exploration of animations and simulations as part of their learning process. Finally, we present some of the first experiences from classroom tests of the quantum physics modules.
WKB APPROXIMATION TO THE MODIFIED MILD-SLOPE EQUATION

WKB approximation for water wave scattering by rapidly varying topography is obtained from a modified mild-slope equation of the general form by Porter (2003). The present WKB solution is reduced to the previous study where shallow water conditions are present. WKB models from the transformed mild-slope equation, without the described bottom curvature modification, show better performance than those by the original developed mild-slope equation. The underlying significance of the present equation is discussed in the context of linear wave scattering. The selected figures representing our results further characterize main feature of this study.
Youth and Young Adults

This review aims to identify self-report instruments examining aspects of transition to parenthood for use in practice and research. After performing a literature search in Embase, Medline, Web of Science, Cochrane, PsycINFO and Google Scholar, the Patient Reported Outcome Measures (PROMs) measuring (aspects of) transition to parenthood during pregnancy or up to 1-year postpartum were identified. Following COSMIN guidelines for systematic reviews on PROMs, the quality of the PROM development and PROM content validity was evaluated. From the 129 included studies, 39 PROMs assessed aspects of transition to parenthood. A total of 32 PROMs were included in the evaluation. The development quality of 30/32 PROMS was mostly rated as inadequate and the quality of 15 content validity studies was mostly rated as doubtful. All PROMs received inadequate or doubtful ratings on content validity. Most of the PROMs measuring aspects of the transition to parenthood didn’t include parents’ points of view when developing them. Many PROMs are being used for a long time without reassessing relevance, comprehensiveness, and comprehensibility among parents and/or practitioners. It is recommended that researchers and healthcare professionals assess content validity of the PROM before use with the target population.
On the Wedderburn principal theorem for commutative power-associative algebras

Introduction. Let A be a strictly power-associative algebra of characteristic not two with radical N and such that the difference algebra A N is separable. Then we say that A has a Wedderburn decomposition if A has a subalgebra S _ A N with A = S + N (vector space direct sum). Since the characterization of the simple, and hence semisimple, commutative strictly power-associative algebras is nearly complete (see [10]) it is desirable to see if a Wedderburn decomposition can be given for them. In ? 2 the problem is reduced to the case where A has a unity element and A N is simple. In ? 3 we show that if A N is simple and does not have two as the maximum number of pairwise orthogonal primitive idempotents, then A has a Wedderburn decomposition (Corollary 3.3). The counterexample to a general decomposition theorem (? 5) shows that this is the best possible result of that type. Our other major result (Theorem 4.1) is that stable algebras have Wedderburn decompositions. It is known that associative [1, Theorem 23, p. 47], alternative [12], and Jordan [2], [11] algebras have Wedderburn decompositions. In each of these cases the proof is essentially effected in two stages, namely, N2 = 0 and N2 # 0. In our results we do not have anything corresponding to the case N2 = 0 but our basic tools (Lemma 3.2 and Theorem 4.1) are conceptually based on the same idea as the usual induction proof employed in the case N2 # 0. As a matter of terminology, by an algebra we will always mean a finite dimensional vector space with a multiplication defined which satisfies both distributive laws. An algebra A is called power-associative if x'x# = x a+# for all positive integers oc and ,B and every x eA. A is called strictly power-associative if AK is power-associative for every scalar extension K of the base field. In [7] Kokoris shows that, for commutative algebras of characteristic not 2, 3, or 5, powerassociativity and strict power-associativity are equivalent concepts. The radical of a strictly power-associative algebra is the unique maximal nil ideal of A and a non-nil algebra with zero radical is called semisimple. A is called separable if AK is semisimple for every scalar extension K of the base field. The basic structure theory of commutative strictly power-associative algebras of characteristic not 2, 3, or 5 was given by Albert in [4] and extended to charac-
Deconvolving feeding niches and strategies of abyssal holothurians from their stable isotope, amino acid, and fatty acid composition

Holothurians are the dominant megabenthic deposit feeders in the Peru Basin (South-East Pacific) and feed to various degrees of selectively on the heterogenous pool of sedimentary detritus, but diet preferences for most holothurian species are unknown. This study reconstructs the diets of 13 holothurian species of the orders Elasipodida, Holothuriida, and Synallactida, from bulk stable isotope analyses (δ13C, δ15N) of holothurian body walls and guts, gut contents, and feces that were combined with compound-specific stable isotope analyses of amino acids, phospholipid-derived fatty acids, and neutral lipid-derived fatty acids in the body wall. Fatty acid concentrations showed high levels of storage lipids, an likely adaption to limited food supply to abyssal plains. Amino acid δ15N isotope values allowed estimating trophic levels of holothurian species and calculating heterotrophic re-synthesis of amino acids. Fatty acids served as trophic markers for feeding on diatom- and dinoflagellate derived phytodetritus, bacteria, Foraminifera, and detritus containing the PUFA C22:1ω9-cis. Several holothurian species seemed to be secondary consumers of detritus, while bacteria in their guts were primary consumers of this detritus. A Sørensen–Dice coefficient based cluster analysis using data of trophic levels, levels of heterotrophic re-synthesis of amino acids, feeding selectivity, and food sources/ diet suggested three trophic groups, characterized by different trophic levels. We show that this multi-biomarker driven approach allows to deconvolve trophic niches and feeding selectivity in one of the most challenging environments on earth and to identify dependence of deep-sea species to organic matter inputs that vary with season and/or climate.
Coordinate metrology using scanning probe microscopes

New positioning, probing and measuring strategies in coordinate metrology are needed for the accomplishment of true three-dimensional characterization of microstructures, with uncertainties in the nanometre range. In the present work, the implementation of scanning probe microscopes (SPMs) as systems for coordinate metrology is discussed. A new non-raster measurement approach is proposed, where the probe is moved to sense points along free paths on the sample surface, with no loss of accuracy with respect to traditional raster scanning and scan time reduction. Furthermore, new probes featuring long tips with innovative geometries suitable for coordinate metrology through SPMs are examined and reported.