Miracle-dz/UniFAR-FTUs huggingface dataset:
An overview of almost 20 years' research on cold fusion

A review of The Science of Low Energy Nuclear Reaction: A Comprehensive Compilation of Evidence and Explanations about Cold Fusion, by E. Storms with Forewords by M.C. H. McKubre and D.J. Nagel, Singapore, World Scientific Publishing Company, 2007, xxii þ 312 pp., £39.00 (hardback), ISBN13 978 981 270 620 1, ISBN10 981 270 620 8. Scope: technical survey. Level: general reader, professional and specialist.
A VLT/FLAMES survey for massive binaries in Westerlund 1

Context. Recent observational studies indicate that a large number of OB stars are found within binary systems which may be expected to interact during their lifetimes. Significant mass transfer or indeed merger of both components is expected to modify evolutionary pathways, facilitating the production of exceptionally massive stars which will present as blue stragglers. Identification and characterisation of such objects is crucial if the efficiency of mass transfer is to be established; a critical parameter in determining the outcomes of binary evolutionary channels. Aims. The young and coeval massive cluster Westerlund 1 hosts a rich population of X-ray bright OB and Wolf–Rayet stars where the emission is attributed to shocks in the wind collision zones of massive binaries. Motivated by this, we instigated a study of the extremely X-ray luminous O supergiants Wd1-27 and -30a. Methods. We subjected a multi-wavelength and -epoch photometric and spectroscopic dataset to quantitative non-LTE model atmosphere and time-series analysis in order to determine fundamental stellar parameters and search for evidence of binarity. A detailed examination of the second Gaia data release was undertaken to establish cluster membership. Results. Both stars were found to be early/mid-O hypergiants with luminosities, temperatures and masses significantly in excess of other early stars within Wd1, hence qualifying as massive blue stragglers. The binary nature of Wd1-27 remains uncertain but the detection of radial velocity changes and the X-ray properties of Wd1-30a suggest that it is a binary with an orbital period ≤10 days. Analysis of Gaia proper motion and parallactic data indicates that both stars are cluster members; we also provide a membership list for Wd1 based on this analysis. Conclusions. The presence of hypergiants of spectral types O to M within Wd1 cannot be understood solely via single-star evolution. We suppose that the early-B and mid-O hypergiants formed via binary-induced mass-stripping of the primary and mass-transfer to the secondary, respectively. This implies that for a subset of objects massive star-formation may be regarded as a two-stage process, with binary-driven mass-transfer or merger yielding stars with masses significantly in excess of their initial “birth” mass.
Raman scattering on intrinsic surface electron accumulation of InN nanowires

An intrinsic property of vertically aligned InN nanowire (NW) ensembles have been investigated by analysis of coupled longitudinal optical (LO) phonon mode using μ-Raman scattering. Spectra were recorded in backscattering geometries in parallel and perpendicular to the axis of the NWs. The width of surface accumulation layer is estimated from the LO phonon peak intensity ratios. The carrier concentration is extracted to be 6.7×1016 cm−3. The pronounced peak at 627.2 cm−1 is related to the interaction of phonons with surface electrons. The surface charge density, Nsc is calculated to be ∼2.55×1013 cm−2 which provides surface accumulation field strength of 5.5 Mv/cm.
Consistent derivation of the Hawking effect for both nonextremal and extremal Kerr black holes

It is believed that extremal black holes do not emit Hawking radiation as understood by taking extremal limits of nonextremal black holes. However, it is debated whether one can make such a conclusion reliably starting from an extremal black hole, as the associated Bogoliubov coefficients which relate ingoing and outgoing field modes do not satisfy the required consistency condition. We address this issue in a canonical approach first by presenting an exact canonical derivation of the Hawking effect for nonextremal Kerr black holes. Subsequently, for extremal Kerr black holes, we show that the required consistency condition is satisfied in the canonical derivation and it produces zero number density for Hawking particles. We also point out the reason behind the reported failure of Bogoliubov coefficients to satisfy the required condition.
Tunneling through a multigrain system: Deducing sample topology from nonlinear conductance

We study a current transport through a system of a few grains connected with tunneling links. The exact solution is given for an arbitrarily connected double-grain system with a shared gate in the framework of the orthodox model. The result is generalized for multigrain systems with strongly different tunneling resistances. We analyze the large-scale nonlinear conductance and demonstrate how the sample topology can be unambiguously deduced from the spectroscopy pattern (differential conductance versus gate-bias plot). We present experimental data for a multigrain sample and reconstruct the sample topology. A simple selection rule is formulated to distinguish samples with spectral patterns free from spurious disturbance caused by recharging of some grains nearby. As an example, we demonstrate experimental data with additional peaks in the spectroscopy pattern, which cannot be attributed to coupling to additional grains. The approach can be used to judge the sample topology when it is not guaranteed by fabrication and direct imaging is not possible.
Gamma-Ray Burst Afterglows from Anisotropic Jets

Some progenitor models of gamma-ray bursts (GRBs; e.g., collapsars) may produce anisotropic jets in which the energy per unit solid angle is a power-law function of the angle (∝θ-k). We calculate light curves and spectra for GRB afterglows when such jets expand either in the interstellar medium or in the wind medium. In particular, we take into account two kinds of wind: one (n ∝ r-3/2) possibly from a typical red supergiant star and another (n ∝ r-2) possibly from a Wolf-Rayet star. We find that in each type of medium, one break appears in the late-time afterglow light curve for small k but becomes weaker and smoother as k increases. When k ≥ 2, the break seems to disappear, but the afterglow decays rapidly. Thus, one expects that the emission from expanding, highly anisotropic jets provides a plausible explanation for some rapidly fading afterglows whose light curves have no break. We also present good fits to the optical afterglow light curve of GRB 991208. Finally, we argue that this burst might arise from a highly anisotropic jet expanding in the wind (n ∝ r-3/2) from a red supergiant to interpret the observed radio to optical band afterglow data (spectrum and light curve).
Hot Stars: Old-Fashioned or Trendy?

Spectroscopic analyses with the intention of the interpretation of the UV-spectra of the brightest stars as individuals ‐ supernovae ‐ or as components of starforming regions ‐ massive O stars ‐ provide a powerful tool with great astrophysical potential for the determination of extragalactic distances and of the chemical composition of star-forming galaxies even at high redshifts. The perspectives of already initiated work with the new generation of tools for quantitative UV-spectroscopy of Hot Stars that have been developed during the last two decades are presented and the status of the continuing effort to construct corresponding models for Hot Star atmospheres is reviewed. Since the physics of the atmospheres of Hot Stars are strongly affected by velocity expansion dominating the spectra at all wavelength ranges, hydrodynamic model atmospheres for O-type stars and explosion models for Supernovae of Type Ia are necessary as basis for the synthesis and analysis of the spectra. It is shown that stellar parameters, abundances, and stellar wind properties can be determined by the methods of spectral diagnostics already developed. Additionally, it will be demonstrated that models and synthetic spectra of Type Ia Supernovae of required quality are already available. These will make it possible to tackle the question of whether Supernovae Ia are standard candles in a cosmological sense, confirming or disproving that the current SN-luminosity distances indicate accelerated expansion of the universe. In detail we discuss applications of the diagnostic techniques by example of two of the most luminous O supergiants in the Galaxy and a standard Supernova of Type Ia. Furthermore, it is demonstrated that the spectral energy distributions provided by state-of-the-art models of massive O stars lead to considerably better agreement with observations if used for the analysis of H II regions. Thus, an excellent way of determining extragalactic abundances and population histories is offered. Moreover, the importance of Hot Stars in a broad astrophysical context will be discussed. As they dominate the physical conditions of their local environments and the life cycle of gas and dust of their host galaxies, special emphasis will be given to the corresponding diagnostic perspectives. Beyond that, the relevance of Hot Stars to cosmological issues will be considered.
Interaction corrections to two-dimensional hole transport in thelarge−rslimit

The metallic conductivity of dilute two-dimensional holes in a GaAs HIGFET (Heterojunction Insulated-Gate Field-Effect Transistor) with extremely high mobility and large r{sub s} is found to have a linear dependence on temperature, consistent with the theory of interaction corrections in the ballistic regime. Phonon scattering contributions are negligible in the temperature range of our interest, allowing comparison between our measured data and theory without any phonon subtraction. The magnitude of the Fermi liquid interaction parameter F{sub 0}{sup {sigma}} determined from the experiment, however, decreases with increasing r{sub s} for r{sub s} {approx}> 22, a behavior unexpected from existing theoretical calculations valid for small r{sub s}.
A Temperature‐Sensitive Phosphor Used to Measure Surface Temperatures in Aerodynamics

A thin sheet of a temperature‐sensitive phosphor has been used to show the distribution of temperature on the surface of a flat plate in supersonic flow. Calibration of the phosphor is described, and a photograph is shown. Use of a photomultiplier tube permits one to determine the temperature as a function of time, from which recovery temperatures and heat transfer coefficients may be deduced.
Global Stability of a Delayed SIRI Epidemic Model with Nonlinear Incidence

In this paper we propose the global dynamics of an SIRI epidemic model with latency and a general nonlinear incidence function. The model is based on the susceptible-infective-recovered (SIR) compartmental structure with relapse (SIRI). Sufficient conditions for the global stability of equilibria (the disease-free equilibrium and the endemic equilibrium) are obtained by means of Lyapunov-LaSalle theorem. Also some numerical simulations are given to illustrate this result.
Optical Method for Determination of Carrier Density in Modulation Doped Quantum Wells

An optical method is suggested to determine the concentration of two-dimensional electrons in modulation-doped quantum wells at low and moderate electron densities between 10 9 and 2 × 10 11 cm -2 . The method is based on an analysis of magneto-reflectivity spectra of charged excitons (trions). The circular polarization degree and the oscillator strength of the charged excitons contain information about the density and spin polarization of two-dimensional electron gas. The method is applied to CdTe/(Cd,Mg)Te and ZnSe/(Zn,Mg)(S,Se) heterostructures.
On coherent structures in the compressible turbulent round jet

The presence of two-dimensional coherent structures in the near-field of the round jet has been established by several experimental investigations and direct Navier-Stokes simulations (DNS). Their study has a great importance to improve the prediction of unsteady flows dominated by large scale structures. Indeed, coherent structures play a determinant role on turbulence and flow evolution. The goal of this numerical study is to apply the semi-deterministic modelling, a method close to the large eddy simulation (LES), to the simulation of compressible round jets. This allows the simulation of natural unsteadiness without any flow excitation. A free jet configuration is computed for three Mach numbers of 0.3, 0.96 and 1.5 to evaluate the influence of compressibility effects on instability, Strouhal number and expansion rate. There is not quantitative comparisons on flow quantities with experimental data, except for the Strouhal number, due to the discrepancies between the configuration computed here and those experimentally investigated in past studies. The numerical results on coherent structures are validated across a comparison on the Strouhal number of the preferred mode. The results on the evolution of the Strouhal number with the Mach number are in excellent agreement with previous experiments. Moreover, the evolution of the large scale vortices in the flow is well correlated by experimental and DNS results obtained on other configurations.
Localization in a Driven Two-Level Dynamics

A periodically driven two-state dynamics, being analysed within the Floquet formalism, exhibits localization of the amplitude dynamics in an infinite frequency range, extending from the bare tunnel splitting up to infinity. In contrast, the suppression of tunnelling in a driven symmetric double well is restricted to a limited frequency regime, extending from the bare tunnel splitting up to the first resonance frequency with higher-lying states. With the amplitude dynamics of a periodically driven two-level system not being restricted to describe coherent tunnelling transport only, the localization phenomenon within the infinite frequency range does allow for novel applications for systems in strong laser fields.
Mass zeros in the one-loop effective actions of QED in 1+1 and 3+1 dimensions

It is known that the one-loop eﬀective action of QED 2 is a quadratic in the ﬁeld strength when the fermion mass is zero: all potential higher order contributions beyond second order vanish. For nonzero fermion mass it is shown that this behavior persists for a general class of ﬁelds for at least one value of the fermion mass when the external ﬁeld’s ﬂux Φ satisﬁes 0 < | e Φ | < 2 π . For QED 4 the mass-shell renormalized one-loop eﬀective action vanishes for at least one value of the fermion mass for a class of smooth, square integrable background gauge ﬁelds provided a plausible zero-mass limit exists.
REVISITING STUDIES OF THE STATISTICAL PROPERTY OF A STRONG GRAVITATIONAL LENS SYSTEM AND MODEL-INDEPENDENT CONSTRAINT ON THE CURVATURE OF THE UNIVERSE

In this paper, we use a recently compiled data set, which comprises 118 galactic-scale strong gravitational lensing (SGL) systems to constrain the statistical property of the SGL system as well as the curvature of the universe without assuming any fiducial cosmological model. Based on the singular isothermal ellipsoid (SIE) model of the SGL system, we obtain that the constrained curvature parameter is close to zero from the SGL data, which is consistent with the latest result of Planck measurement. More interestingly, we find that the parameter f in the SIE model is strongly correlated with the curvature . Neglecting this correlation in the analysis will significantly overestimate the constraining power of SGL data on the curvature. Furthermore, the obtained constraint on f is different from previous results: (68% confidence level [C.L.]), which means that the standard singular isothermal sphere (SIS) model (f = 1) is disfavored by the current SGL data at more than a C.L. We also divide all of the SGL data into two parts according to the centric stellar velocity dispersion and find that the larger the value of for the subsample, the more favored the standard SIS model is. Finally, we extend the SIE model by assuming the power-law density profiles for the total mass density, , and luminosity density, , and obtain the constraints on the power-law indices: and at a 68% C.L. When assuming the power-law index , this scenario is totally disfavored by the current SGL data, .
Prevalence, risk factors, and consequences of hypothyroidism among pregnant women in the health region of Lleida: A cohort study

Background: Primary maternal hypothyroidism is defined as the increase of TSH levels in serum during pregnancy. Hypothyroidism in pregnancy is the second most common endocrine disease, after diabetes mellitus, with a prevalence ranging between 3.2 and 5.5%. Its variability depends on ethnical differences. Hypothyroidism in pregnancy is associated with other chronic diseases and fetal and maternal outcomes. Objective: To analyze the prevalence of hypothyroidism among multiethnic pregnant women, and to evaluate the comorbidity with chronic diseases and outcomes leaded during pregnancy and newborn. Methods: Retrospective observational cohort study in pregnant women during the years 2012- 2018 in the health region of Lleida. The relationship of hypothyroidism with different variables was analyzed by calculating the adjusted odds ratio (aOR) and the 95% confidence intervals (CI) with multivariate logistic regression models. Results: We analyzed a sample of 17177 pregnant women, which represents more than 92% of the total of pregnant women in the health region of Lleida. The annual prevalence of hypothyroidism was 5.7-7.1%. According to the region of origin, the lowest prevalence was found in the population from Sub Saharian Africa (2.1%), while the highest was from Asia and the Middle East (8.6%). Other factors associated with hypothyroidism were age, hypertension, diabetes mellitus, and dyslipidemia. In addition, we did not observe an effect of hypothyroidism on the course of pregnancy, childbirth, and on the newborn. Finally, there was a good control of the disease during pregnancy. Conclusions: The prevalence of hypothyroidism in pregnancy was 6,5% in this study which depends on the country of origin, lower values were found in Sub Saharian African women and higher in those from Asia and the Middle East. Hypothyroidism was associated with age, diabetes mellitus, arterial hypertension, or dyslipidemia, and was not related to the Apgar score or the weight of the newborn.
Tuning methods for metamaterials

We discuss a novel tuning method based on continuous adjustment of metamaterial lattice parameters. This method provides for remarkable tuning of transmission characteristics through a subtle displacement of metamaterial layers. While the effective medium theory predicts correctly the general tuning characteristics, it turns out that the particular tuning pattern is determined by the peculiarities of near-field interaction between the metamaterial elements. We describe the modes of this interaction and provide qualitative explanations to the performance observed numerically and experimentally.
An exact integral equation for the renormalized Fermi surface

The true Fermi surface of a fermionic many-body system can be viewed as a fixed point manifold of the renormalization group (RG). Within the framework of the exact functional RG we show that the fixed point condition implies an exact integral equation for the counter-term which is needed for a self-consistent calculation of the Fermi surface. In the simplest approximation, our integral equation reduces to the self-consistent Hartree–Fock equation for the counter-term.
Re-entrance during nonequilibrium relaxation

We consider nonequilibrium critical dynamics of the two-dimensional Ising model for which the initial state is prepared by switching on random fields with zero mean and variance H. In the initial state there is no magnetic order but the clusters of parallel spins have a percolation transition for small enough H. Using heat-bath dynamics we measure the relaxation of the magnetization which shows a re-entrance in time. Due to cluster dissolution in the early time regime there is a decrease of the magnetization, followed by an increase due to nonequilibrium domain growth which itself turns to a decrease due to equilibrium relaxation. The power law decay of the nonequilibrium autocorrelation function is not influenced by the percolation in the initial state.
The Carnegie Supernova Project I: analysis of stripped-envelope supernova light curves

Stripped-envelope (SE) supernovae (SNe) include H-poor (Type IIb), H-free (Type Ib) and He-free (Type Ic) events thought to be associated with the deaths of massive stars. The exact nature of their progenitors is a matter of debate. Here we present the analysis of the light curves of 34 SE SNe published by the Carnegie Supernova Project (CSP-I), which are unparalleled in terms of photometric accuracy and wavelength range. Light-curve parameters are estimated through the fits of an analytical function and trends are searched for among the resulting fit parameters. We found a tentative correlation between the peak absolute $B$-band magnitude and $\Delta m_{15}(B)$, as well as a correlation between the late-time linear slope and $\Delta m_{15}$. Making use of the full set of optical and near-IR photometry, combined with robust host-galaxy extinction corrections, bolometric light curves are constructed and compared to both analytic and hydrodynamical models. From the hydrodynamical models we obtained ejecta masses of $1.1-6.2$ $M_{\odot}$, $^{56}$Ni masses of $0.03-0.35$ $M_{\odot}$, and explosion energies (excluding two SNe Ic-BL) of $0.25-3.0\times10^{51}$ erg. Our analysis indicates that adopting $\kappa = 0.07$ cm$^{2}$ g$^{-1}$ as the mean opacity serves to be a suitable assumption when comparing Arnett-model results to those obtained from hydrodynamical calculations. We also find that adopting He I and O I line velocities to infer the expansion velocity in He-rich and He-poor SNe, respectively, provides ejecta masses relatively similar to those obtained by using the Fe II line velocities. The inferred ejecta masses are compatible with intermediate mass ($M_{ZAMS} \leq 20$ $M_{\odot}$) progenitor stars in binary systems for the majority of SE SNe. Furthermore, the majority of our SNe is affected by significant mixing of $^{56}$Ni, particularly in the case of SNe Ic.
Fabrication and Bonding Strength of Bonded Silicon-Quartz Wafers

A multiply repeated process of thinning of silicon layer and annealing of the bonded silicon-quartz interface is proposed for tight bonding between a silicon wafer and a quartz wafer which have different thermal expansion coefficients. Silicon layers on quartz with a thickness of 2 µm±0.5 µm were debonded by a high temperature annealing over 650 C, whereas in the case of thinner silicon layers with a thickness under 0.5 µm tensile strengths over 80 MPa (800 kgf/cm2) were obtained in the temperature range from 700 C to 1100 C.
Photon pair production with soft gluon resummation in hadronic interactions

The production rate and kinematic distributions of isolated photon pairs produced in hadron interactions are studied. The effects of the initial-state multiple soft-gluon emission to the scattering subprocesses q{bar q},qg, and gg{r_arrow}{gamma}{gamma}X are resummed with the Collins-Soper-Sterman soft gluon resummation formalism. The effects of fragmentation photons from qg{r_arrow}{gamma}q, followed by q{r_arrow}{gamma}X, are also studied. The results are compared with data from the Fermilab Tevatron collider. A prediction of the production rate and kinematic distributions of the diphoton pair in proton-nucleon reactions is also presented. {copyright} {ital 1998} {ital The American Physical Society}