Miracle-dz/UniFAR-FTUs huggingface dataset:
Influence of inter-strand electrical and thermal conductivity on stability of Rutherford cables in accelerator magnets

Influence of inter-strand electrical and thermal conductivity on stability of multi-strand superconducting cables is studied theoretically based on a 3-strand cable model. The simulation model takes into account transient heat-transfer characteristics between strand surface and helium, inter-strand current sharing, heat conduction as well as variation of thermal physical properties with temperature and magnetic field. Minimum quench energy is calculated both in case of uniform current distribution and in the case of nonuniform current distribution. The results show that the influence of inter-strand electrical conductivity on minimum quench energy increases as the nonuniformity of current distribution increases. Calculations were performed in view of the special situation of Rutherford cables in dipole magnets for particle accelerators. The results demonstrated that differences in inter-strand contact properties could lead to evident different ramp-rate limitation behavior. It is concluded that serious ramp-rate limitation problem could be avoided by keeping inter-strand electrical and thermal conductivity in a proper range.
SCALABLE MORTAR METHODS FOR ELLIPTIC PROBLEMS ON MANY SUBREGIONS

We discuss substructuring domain decomposition methods for the numerical solution of elliptic partial differential equations. The domain is decomposed into geometrically conforming regions. A finite element triangulation on the subdomains is used which is non-matching across the interfaces. A weak continuity (mortar) condition is imposed on the solution at the interface. Our model problem is a second order elliptic equation in the plane with discontinuous diffusion coefficients across the subdomain interfaces. We solve the problem by a Finite Element Tearing and Interconnection dual-primal (FETI-DP) method. We introduce and analyze a preconditioner with a special scaling of coefficients and step parameters which extends a preconditioner of M. Dryja and O. Widlund for continuous problems with mortar discretization, see [32], to problems with discontinuous coefficients. We establish convergence bounds showing that our preconditioner is almost optimal with constants independent of the jumps of coefficients and step parameters. Extensive computational evidence is presented that illustrates an almost optimal convergence for a variety of situations (subdomain ordering, distribution of coefficients, grid ratios, number of subregions) for both continuous and discontinuous problems, see [25]. We also analyze the scalability of the method. A parallel algorithm is presented as well as numerical results from its implementation in C and MPI on up to 1024 processors. The algorithm is then improved by using external software libraries such as PETSc, SPOOLES and MUMPS. When increasing the size of the problem with a fixed number of degrees of freedom per processor, the results show an almost linear parallel scalability, see [26]. viii Finally we consider a generalization of this method to the two-dimensional fourth order plate problem by using reduced Hsieh-Clough-Tocher (RHCT) finite elements. We discuss the implementation and present experimental results on two subdomains showing that our preconditioner for the second order problem can be efficiently applied to the plate problem.
SiO Masers in a Scutum Massive Star Cluster of Red Supergiants

We have detected five objects toward a Scutum massive star cluster of red supergiants in the SiO J = 1-0, v = 1 or v = 2 transitions. The radial velocity data indicate that four of the detections are cluster members and that the other, which is located close to the X-ray source AX 1838-0655, is a foreground object. The high velocity resolution of the maser lines provides a more accurate determination of the radial velocity (120 km s-1) and velocity dispersion (~2 km s-1) of the cluster and, hence, of the distance (6.5 kpc) and luminosities of the stars. We discuss the implications of these measurements in constraining the relationships between SiO masers and mass-loss rate and modeling the cluster age and mass.
Apalutamide Prevents SARS-CoV-2 Infection in Lung Epithelial Cells and in Human Nasal Epithelial Cells

In early 2020, the novel pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, and rapidly propagated worldwide causing a global health emergency. SARS-CoV-2 binds to the angiotensin-converting enzyme 2 (ACE2) protein for cell entry, followed by proteolytic cleavage of the Spike (S) protein by the transmembrane serine protease 2 (TMPRSS2), allowing fusion of the viral and cellular membranes. Interestingly, TMPRSS2 is a key regulator in prostate cancer (PCa) progression which is regulated by androgen receptor (AR) signaling. Our hypothesis is that the AR signaling may regulate the expression of TMPRSS2 in human respiratory cells and thus influence the membrane fusion entry pathway of SARS-CoV-2. We show here that TMPRSS2 and AR are expressed in Calu-3 lung cells. In this cell line, TMPRSS2 expression is regulated by androgens. Finally, pre-treatment with anti-androgen drugs such as apalutamide significantly reduced SARS-CoV-2 entry and infection in Calu-3 lung cells but also in primary human nasal epithelial cells. Altogether, these data provide strong evidence to support the use of apalutamide as a treatment option for the PCa population vulnerable to severe COVID-19.
Linking Urban Planning, Community Environment, and Physical Activity: A Socio-Ecological Approach

Lack of physical activity is a growing concern among public health advocates and urban planners. Our socio-ecological model incorporates urban planning and World Health Organization actions on physical activity to identify key factors related to leisure-time physical activity at the community level. Our 2019 nationwide US survey of 1312 communities enables examination of the influence of individual, community, and policy levels on physical activity. Individual factors—poverty, aging, minority population, and longer commuting time—result in lower physical activity. Community-level factors have both positive and negative effects. Physical activity is lower in rural and suburban communities, but higher in communities with more transportation services, recreation and social activities, and safety. Communities with mixed-use neighborhoods and complete streets also show higher levels of physical activity. At the policy level, zoning and cross-agency collaboration have an indirect effect on physical activity by increasing these community-level factors. This suggests an alternative approach to promoting physical activity. Local governments can promote transportation, recreation and safety, especially in rural and minority communities lacking active-friendly built environments and facing challenges from aging population, poverty, and longer commuting time. This socio-ecological approach can assess multilevel factors related to physical activity in other countries.
Hysteresis and magnetic viscosity in a Nd-Fe-B permanent magnet

Measurements have been made of the hysteresis of thermally and field-demagnetized sintered specimens of a Nd-Fe-B permanent magnet. Sets of minor hysteresis loops have been obtained by a gradual increase in the maximum applied field thus enabling the intrinsic coercivity and the remanence coercivity to be plotted as a function of the maximum applied field. These results show that there is a threshold field which must be exceeded before a substantial coercivity can be obtained. Measurements of the magnetic viscosity have also been made which show that the change in the magnetization in a static reverse field varies with the logarithm of the time for which the field is applied. The slopes of the curves depended on the applied field; the maximum slope was observed when the applied field was equal to the coercivity.
Statistical distribution of the field scattered by rough layered interfaces: formulae derived from the small perturbation method

We present a statistical study of electromagnetic wave scattering by a stack of two random rough interfaces that are characterised by Gaussian distributed heights and by exponential correlation functions. These interfaces can be correlated or not. The coherent and incoherent intensities and the statistical distribution of the scattered field in modulus and phase are obtained using the Rayleigh expansion and the small perturbation method. For a structure of finite extension, we show that the modulus follows a Hoyt law and the phase is not uniform. For a structure of infinite extension, whether the interfaces are correlated or not, the modulus of the field follows a Rayleigh law while the phase is uniform.
Sheared flow-driven vortices and solitary waves in a non-uniform plasma with negative ions and non-thermal distributed electrons

Abstract The coupled drift-ion acoustic (DIA) waves in an inhomogeneous magnetoplasma having negative and positive ions can be driven by the parallel sheared flows in the presence of Cairns distributed non-thermal electrons. The coupled DIA waves can become unstable due to shear flows. The conditions of modes instability are discussed with effects of non-thermal electrons. These are the excited modes and start interactions among themselves. The interaction is governed by the Hasegawa–Mima equations with analytical solutions in the form of a vortex chain and dipolar vortex. On the other hand, for scalar nonlinearity the Kortweg deVries-type equation is obtained with solitary wave solution. Possible application of the work to the space and laboratory plasmas are highlighted.
Omnibus tests of multinormality based on skewness and kurtosis

Measures of univariate skewness and kurtosis have long been used as a test of univariate normality, several omnibus test procedures based on a combination of the measures having been proposed, see Pearson, D’Agestino and Bowman (1977) and Mardia (1979). Mardia (1970) proposed measures of multivariate skewness and kurtosis, and constructed a test of multinormality based on these measures. we obtain the correlation between these measures and propose several omnibus tests using the two measures. The performances of these tests are compared by means of a Monte Carlo study.
Finite-Time Ruin Probability with Heavy-Tailed Claims and Constant Interest Rate

At first the paper investigates the asymptotic behavior of the finite-time ruin probability with constant interest rate and subexponentially tailed claim sizes, which extends the result recently established by Tang [14] for the classical risk model to the delayed renewal risk model; then, within the intersection class of the claim sizes with subexponential tails and the claim sizes with dominatedly varying tails, the paper discusses the finite-time ruin probability with claims arriving according to an arbitrary counting process.
Effect of annealing on the mobility and morphology of thermally activated pentacene thin film transistors

Pentacene thin film transistors (TFTs) were fabricated by the organic molecular beam deposition method. The TFTs were characterized in order to study the effect of thermal annealing on the morphology and carrier mobility of the transistors. For all the TFT samples the mobility exhibited an Arrhenius relationship with temperature, indicating a thermally activated transport that could be explained by the carrier trap and thermal release transport mechanism. Therefore, in order to investigate the annealing effect, we tested the data for a significant period of time after annealing until the temperature recovered to room temperature, so that the thermal activation effect was screened and possible effects of thermal expansion and stress were also ruled out. As a result, we found that only with a temperature below a critical temperature of approximately 45°C could annealing improve the mobility, while annealing with T>50°C would decrease the mobility compared to the value before annealing. Atomic force microsco.
Structure of Hot Molecular Cores

Hot molecular cores are a short-lived phase of massive star formation: the massive stars have heated up the dense molecular gas in which they are deeply embedded, but have not yet ionized and disrupted it. Information on their structure (density, temperature, velocity, molecular abundances) is needed both for research on massive star formation and for astrochemistry. We constrain their structure by radiative transfer modeling of a variety of molecular lines, including from highly excited states, using APEX and Herschel/HIFI. To spatially resolve the hot molecular gas, we performed VLA and SMA observations. In this article, we summarize some to the results.
The transition from carbon dust to silicate production in low-metallicity asymptotic giant branch and super-asymptotic giant branch stars

We compute the mass and composition of dust produced by stars with masses in the range and with a metallicity of Z= 0.001 during their asymptotic giant branch (AGB) and super-AGB phases. Stellar evolution is followed from the pre-main-sequence phase using the code aton which provides, at each time-step, the thermodynamics and the chemical structure of the wind. We use a simple model to describe the growth of the dust grains under the hypothesis of a time-independent, spherically symmetric stellar wind. Although part of the modelling which describes the stellar outflow is not completely realistic, this approach allows a straight comparison with results based on similar assumptions present in the literature, and thus can be used as an indication of the uncertainties affecting the theoretical investigations focused on the dust formation process in the surroundings of AGB stars. We find that the total mass of dust injected by AGB stars in the interstellar medium does not increase monotonically with stellar mass and ranges between a minimum of for the 1.5- stellar model up to , for the 6- case. Dust composition depends on the stellar mass: low-mass stars () produce carbon-rich dust, whereas more massive stars, experiencing Hot Bottom Burning, never reach the C-star stage, and produce silicates and iron. This is in partial disagreement with previous investigations in the literature, which are based on synthetic AGB models and predict that, when the initial metallicity is Z= 0.001, carbon-rich dust is formed at all stellar masses. The differences are due to the different modelling of turbulent convection in the super-adiabaticity regime. Also in this case, like for other physical features of the AGB, the treatment of super-adiabatic convection shows up as the most relevant issue affecting the dust formation process. We also investigate super-AGB stars with masses in the range that evolve over an ONe core. Due to a favourable combination of mass-loss and Hot Bottom Burning, these stars are predicted to be the most efficient silicate-dust producers, releasing masses of dust. We discuss the robustness of these predictions and their relevance for the nature and evolution of dust at early cosmic times.
Observations of Mesoscale Circulations within Extratropical Cyclones over the North Atlantic Ocean during ERICA

Abstract Pseudo-dual-Doppler analyses of two mesoscale circulations (20–40 km in horizontal dimensions) that formed along a warm front within a rapidly deepening extratropical cyclone over the ocean are presented. The circulations were analyzed using airborne Doppler radar during ERICA (Experiment on Rapidly Intensifying Cyclones over the Atlantic) IOP (intensive observing period) 4 and are believed to be a type of frontal instability that has not been addressed in past theoretical studies of frontal waves and cyclones. These features may be the shallow circulations that have been documented to play a role in cyclogenesis when they become coupled with an upper-level baroclinic wave. The present case is compared and contrasted with the only other well-analyzed event during ERICA IOP 5. A retrieval of the perturbation pressure and buoyancy fields using the kinematic wind fields is performed in order to facilitate the interpretation of the dynamic structure of these vortices. In addition, a set of equations .
Puzzles and resolutions of information duplication in de Sitter space

This is a thesis which contributes to research in two different fields: theoretical physics and physics education research. The common link between these two research areas is that both involve explorations of abstract physics and mathematical representations, but from different perspectives.The first part of this thesis is situated in theoretical physics. Here a cosmological scenario is explored where a de Sitter phase is replaced with a phase described with a scale factor a(t) ~ tq, where 1/3<1. This scenario could be viewed as an inflationary toy model, and is shown to open up the possibility of an information paradox. This potential paradox is resolved even in the worst case scenario by showing that the time scales involved for such a paradox to occur is of the order of magnitude of the recurrence time for the de Sitter space.The second part of this thesis is situated in physics education research. A number of learning situations that are experienced as abstract by students are explored: probability in one dimensional quantum tunnelling; the mindsets that students adopt towards understanding physics equations used in typical teaching scenarios; and what students focus on when presented with physics equations. The results for the quantum scattering study are four phenomenographic categories of description, for the mind sets study, six epistemological components of mindsets and for the focus on physics equations study, three foci creating five levels of increasing complexity of ways of experiencing physics equations. Pedagogical implications of these results are discussed.
Sensitivity Analysis in Semiparametric Likelihood Models

We provide methods for inference on a finite dimensional parameter of interest, theta in Re^{d_theta}, in a semiparametric probability model when an infinite dimensional nuisance parameter, g, is present. We depart from the semiparametric literature in that we do not require that the pair (theta, g) is point identified and so we construct confidence regions for theta that are robust to non-point identification. This allows practitioners to examine the sensitivity of their estimates of theta to specification of g in a likelihood setup. To construct these confidence regions for theta, we invert a profiled sieve likelihood ratio (LR) statistic. We derive the asymptotic null distribution of this profiled sieve LR, which is nonstandard when theta is not point identified (but is chi^2 distributed under point identification). We show that a simple weighted bootstrap procedure consistently estimates this complicated distribution's quantiles. Monte Carlo studies of a semiparametric dynamic binary response panel data model indicate that our weighted bootstrap procedures performs adequately in finite samples. We provide three empirical illustrations to contrast our procedure to the ones obtained using standard (less robust) methods.
Maximum likelihood estimation of gamma parameters for coarsely binned and truncated raindrop size data

The gamma family of probability densities has recently been used to model raindrop size. However, the traditional approach of using the method of moments to estimate the gamma distribution parameters is known to be biased and can have substantial errors. A recently developed approach combining moment information and a weighted least‐squares analysis generally produces substantially better results. Other procedures superior to the method of moments approach include maximum likelihood. In particular, maximum likelihood estimates have been shown to outperform method of moments estimators, both for the case in which the full range of drop sizes are observed and for the case in which small drop sizes fail to be observed because of the inability of disdrometers to record observations below a threshold.
The non- (cid:2) -part of the number of spanning trees in abelian (cid:2) -towers of multigraphs

Let (cid:2) and p be two distinct primes. We study the p -adic valuation of the number of spanning trees in an abelian (cid:2) -tower of connected multigraphs. This is analogous to the classical theorem of Washington–Sinnott on the growth of the p -part of the class group in a cyclotomic Z (cid:2) -extension of abelian extensions of Q . Furthermore, we show that under certain hypotheses, the number of primes dividing the number of spanning trees is unbounded in such a tower.
An Isotope Study of Carbon Monoxide in the Edge-on Galaxy NGC 891

We present high-resolution simultaneous observations of the edge-on galaxy NGC 891 in 12CO and 13CO emissions. The molecular thin-disk component within 10.7 kpc from the galactic center was completely covered. This data set with accurate relative calibrations of intensity scale and pointing is analyzed to examine radial variation in the physical properties of the molecular gas. The total 13CO/12CO luminosity ratio is 1/6.6. A low 13CO/12CO intensity ratio of 1/(15.4 ± 6.0) is observed in the nuclear disk of about 550 pc in radius. There exists a systematic gradient of the 13CO/12CO intensity ratio in the main galactic disk as a function of galactocentric distance: the 13CO/12CO intensity ratio exhibits a notable peak of ≃1/4.5 near 4 kpc, and decreases systematically outward down to ≲1/10 at 10 kpc. The observational results are analyzed on the basis of a CO excitation analysis. The low 13CO/12CO intensity ratio in the nuclear disk may be attributed to a predominance of warm molecular gas (≳40 K) of moderate gas density (~103 cm-3), while the systematic gradient of the 13CO/12CO intensity ratio in the main disk can be interpreted in terms of radial decrease in the dense molecular gas fraction. Since interstellar gas in the inner part of the galaxy is mostly molecular, this variation will be ascribed to compression of molecular gas with its strength dependent on galactocentric distance rather than dissociation of low-density molecular gas by UV photons from young stars in the inner part of the galaxy.
A duality theorem for a multiple objective fractional optimization problem

Characterizations of efficiency and proper efficiency are given for classes of multiple objective fractional optimization problems. These results are then applied to the case of multiple objective fractional linear problems. A dual problem is given for the multiple objective fractional problem and it is shown that for a properly efficient primal solution the dual solution is also properly efficient.
Quantum‐optical analogies using photonic structures

Engineered photonic waveguides have provided in the past decade an extremely rich laboratory tool to visualize with optical waves the classic analogues of a wide variety of coherent quantum phenomena encountered in atomic, molecular or condensed‐matter physics. As compared to quantum systems, optics offers the rather unique advantage of a direct mapping of the wave function evolution in coordinate space by simple fluorescence imaging or scanning tunneling optical microscopy techniques. In this contribution recent theoretical and experimental advances in the field of quantum‐optical analogies are reviewed. Special attention is devoted to some relevant optical analogies based on the use of curved photonic structures, including: coherent destruction of tunneling in driven bistable potentials; coherent population transfer and adiabatic passage in laser‐driven multilevel atomic systems; quantum decay control and Zeno dynamics; electronic Bloch oscillations and Zener tunneling, Anderson localization and dynamic localization in crystalline potentials.