Miracle-dz/UniFAR-FTUs huggingface dataset:
On charged particle orbits in dipole magnetic fields around Schwarzschild black holes

We consider the motion of charges around Schwarzschild black holes when a magnetic field is present; analysis is focused on the exact solution of Maxwell equations in Schwarzschild spacetime describing dipolar fields generated by current loops around the black hole. This solution deserves particular attention, since it is suggestive of a relation with toroidal currents in accretion discs; with reference to applications of this same field solution, we point out and discuss an existing physical incoherence in past studies, and give the necessary emendation. Critical comparison with previous results is made. The circular orbit characteristics are examined in detail; two sets of solutions are found, both allowing stable circular orbits close to the event horizon, well beyond the Schwarzschild static limit at r = 6M. The existence of potential traps for highly relativistic particles within this same limit is also worth noting, since these same trapped particles may represent an effective source of synchrotron radiation.
Ytterbium fibre laser with a heavily Yb3+-doped glass fibre core

The use of optical fibres with a high concentration of active ions in the fibre core allows the reduction of the active fibre length and the increase in the threshold powers of various nonlinear effects in the fibre, thereby increasing the maximum output power of fibre lasers. For this purpose, we manufactured a highly concentrated ytterbium-doped (~1.0×1021cm-3) phosphate glass for the active fibre core and a pure glass of a similar composition for the fibre cladding. A single-mode fibre is fabricated from these glasses and generation is obtained in an ytterbium laser based on this fibre with the slope efficiency of no less than 60% at a wavelength of 975 nm.
Almost sure asymptotic stability and convergence of stochastic Theta methods applied to systems of linear SDEs in

Abstract Almost sure asymptotic stability of trivial solution and almost sure convergence of stochastic Theta methods applied to bilinear systems of ordinary stochastic differential equations (SDEs) of Itô-type in are proven. For this purpose, we prove and exploit a convergence theorem for non-negative semi-martingale decompositions, and verify a practical criteria based on the uniform boundedness of nonrandom eigenvalues related to certain matrix systems in any dimension d. We do not assume commutativity or simultaneous diagonalizability of drift and diffusion parts as many other authors, neither we restrict our analysis and applicability to only 2D or 3D cases nor to uniform step sizes (since the problem of adequate stochastic test equations cannot be solved within non-anticipative Itô calculus). However, an example of 2D diagonal-noised systems illustrates our approach. The discrete time systems of stochastic Theta methods are driven by L 2-martingales (i.e. martingale differences, not necessarily Gaussian) and can be interpreted as nonautonomous discretizations (e.g. with variable step sizes or dependence on time).
X-ray emission from 4U 2129+47 (= V1727 Cygni) in quiescence

Observations with the ROSAT HRI allow detection of weak X-ray flux from the low-mass X-ray binary (LMXB) 4U 2129+47 during its current quiescent state. The quiescent luminosity is similar to that seen in several other quiescent LMXBs containing neutron stars. The quiescent X-ray light curve may not show the eclipse seen when the source was in its high state, which would indicate that the enhanced vertical structure present in the disk during the high state has collapsed. This in turn provides support for the idea that the vertical structure in LMXB accretion disks is a consequence of high X-ray luminosity. A comparison of the absorption of low-energy X-rays due to the interstellar medium (determined from Einstein IPC observations) and the optical extinction does not rule out the triple system hypothesis.
Distant clusters of galaxies detected by X-rays

The dynamical masses of groups and clusters of galaxies decrease on average with increasing redshift, after the hierarchical cosmogonies dominated by direct collapses of dark matter overdensities. We show that the masses of intracluster plasma emitting in the X-ray band are to decrease more rapidly. We also show that consideration of the intrinsic spread in the dynamical formation times leads us to predict more numerous faint sources at given dynamical mass. The model we compute yields steeper luminosity functions in the X-ray band with a specific change in lookback time: the bright end shifts back
Waldenström macroglobulinemia: diagnosis and treatment

Waldenström macroglobulinemia (WM), according to the 2017 World Health Organization classifi - cation, is defined as the co-occurrence of lymphoplasmacytic lymphoma involving the bone marrow with monoclonal gammopathy of the IgM class regardless of the concentration of monoclonal pro - tein. It is a rare lymphoproliferative disease with distinctive clinical features. Diagnostic character - istics in WM have changed significantly with the discovery of two molecular markers: MYD88 and CXCR4. The mutational status of these markers both affects clinical presentation and has shown therapeutic implications. The choice of treatment in WM is closely dependent on the patient’s age, risk of treatment-related neuropathy, and risk of immunosuppression or secondary malignancies. The therapeutic landscape has broadened in recent years, and the approvals of ibrutinib and zanu - brutinib represent a significant step forward toward better management of the disease
Poisson's ratio for anisotropic elastic materials can have no bounds

Poisson's ratio for isotropic elastic materials is bounded between -1 and 1 / 2 . It is shown that Poisson's ratio for anisotropic elastic materials can have an arbitrarily large positive or negative value under the prerequisite of positive definiteness of strain energy density. The large Poisson's ratio for cubic materials is physically realistic because the strains are bounded.
Periodic Variability of Pre-Main-Sequence Stars in the NGC 2264 OB Association

We summarize the results of an observing campaign to identify periodic pre–main-sequence (PMS) variables in the NGC 2264 OB association. We find 201 periodic candidates. The mean age of the NGC 2264 periodic variables is approximately 30% greater than their counterparts in the Orion Nebula Cluster. Given the difference in mean age between NGC 2264 and Orion, we expect the typical periodic variable in NGC 2264 to have a period shorter by a factor of ∼1.6, if the initial distribution of periods in the two clusters is identical and if stellar angular momentum is conserved. However, we find a period distribution indistinguishable from that found in Orion. This suggests that the angular momenta of a significant fraction of PMS stars in the age range ∼0.4 to ∼4 Myr must be regulated. To examine the hypothesis that disk locking regulates PMS star angular momenta, we use four different disk indicators (U-V, IC-Ks, H-Ks, and Hα) to search for correlations between period and disk indicator. We find no conclusive evidence that more slowly rotating stars have disk indicators, or that faster rotating stars are less likely to have disk indicators.
The Continuum Random Tree III

Let (W(k), k 2 1) be random trees with k leaves, satisfying a consistency condition: Removing a random leaf from R(k) gives R(k - 1). Then under an extra condition, this family determines a random continuum tree ? /, which it is convenient to represent as a random subset of 11. This leads to an abstract notion of convergence in distribution, as n -A o, of (rescaled) random trees En- on n vertices to a limit continuum random tree I/. The notion is based upon the assumption that, for fixed k, the subtrees of En determined by k randomly chosen vertices converge to R(k). As our main example, under mild conditions on the offspring distribution, the family tree of a Galton-Watson branching process, conditioned on total population size equal to n, can be rescaled to converge to a limit continuum random tree which can be constructed from Brownian excursion. abstractly about a projective limit R(oo), but our goal is to give a concrete representation of a limit.
Inherently Incomplete Finite Element Model and Its Effects on Model Updating

Some of the questions regarding the use of measured data to improve a finite element model of a structure to make it better able to predict the dynamic behavior of the structure are addressed. The issues discussed include the following: All such models are truly reduced models, the parameters of a reduced model of a linear structure vary with frequency, a linear model of a linear structure has a limited frequency range of applicability, and there are an infinite number of reasonable models that can match measured data. These and other related concepts are discussed and demonstrated. Of course, because there is no unique solution, questions arise as to how to select the best one, and are there different best models for different applications. It is concluded that new paths of research in this important field are necessary.
El Niño–Southern Oscillation Impacts on Rice Production in Luzon, the Philippines

Abstract This study uses regression analysis to evaluate the relationships among sea surface temperature anomalies (SSTA) averaged over the Nino-3.4 region (5°N–5°S, 120°–170°W), rainfall, and rice production, area harvested, and yield in Luzon, the large island on which most Philippine rice is grown. Previous research on Philippine rice production and El Nino–Southern Oscillation (ENSO) has found negative associations between El Nino events and rice yields in rainfed systems. This analysis goes further and shows that both irrigated and rainfed ecosystems are impacted. It also compares impacts on area harvested and yield. Variations in average July–September Nino-3.4 SSTAs explain approximately 29% of the interannual variations in the deviations of total January–June (dry season) rice production from a polynomial trend for 1970–2005. In contrast, no impact was found on July–December production in either year t or t + 1. The impact of ENSO on dry-season rice production in Luzon appears to be primarily due .
Numerical Investigation of Heat Transfer Enhancement in a Microchannel With Grooved Surfaces

This paper presents a numerical investigation for two types of grooves (rectangular and arc shapes) fabricated in the microchannel surfaces, which leads to enhancement in single-phase cooling. The pressure drop and heat transfer characteristics of the single-phase microchannel heat sink were investigated numerically for laminar flow. For this purpose, the conjugate heat transfer problem involving simultaneous determination of temperature fields in both solid and liquid regions was solved numerically. The numerical model was validated with comparison to experimental data, in which good agreement was seen. A simple microchannel with available experimental data was selected, and it was shown that using grooved surfaces on this microchannel has a noticeable effect and heat removal rate can be increased using this technique. The results depict that the are grooves have a higher heat removal flux compared with rectangular grooves but the latter have a higher coefficient of performance for the case in which grooves are made in the floor and both side walls. Also, it was shown that a grooved microchannel with higher wall thickness and lower mass flow rate of cooling water has a higher heat removal flux and coefficient of performance compared with a simple microchannel with minimum wall thickness. Effect of various sizes and distances of the floor grooves was determined, and the cases for maximum heat removal rate and coefficient of performance for both rectangular and are grooves were obtained.
Large eddy simulation of turbulent channel flows by the variational multiscale method

The variational multiscale formulation of LES is applied to two-dimensional equilibrium and three-dimensional nonequilibrium channel flows. Simple, constant-coefficient Smagorinsky-type eddy viscosities, without wall damping functions, are used to model the decay of small scales, an approach which is not viable for wall-bounded flows within the traditional LES framework. Nevertheless, very good results are obtained.
Flow complexity—a data suitability index for flowline systems

In layout planning the concept of ‘flow dominance’—the situation in which relatively few paths of flow dominate the overall materials movement problem— has been recognized for many years as a guide to whether line layout may be effective. More recently, so-called upper and lower bounds on flow dominance and a parameter‘problem complexity’ based on these bounds have been proposed as being more informative than flow dominance alone. In this paper it is shown that these so-called upper and lower bounds are only bounding values under certain conditions. A new parameter, ‘flow complexity’, is proposed which more effectively measures the complexity of flow. This parameter has a value which does lie between two bounds, one of which implies a pure flow line situation, the other the pure job shop situation.
New-Onset Hyperreligiosity, Demonic Hallucinations, and Apocalyptic Delusions following COVID-19 Infection

Background Neuropsychiatric sequelae of COVID-19 have been documented, including delusions, hallucinations, agitation, and disorganized behavior. Although the mechanisms for these symptoms remain unclear, there has been an increasing body of literature suggesting a correlation between COVID-19 infection and psychosis. Here, we illustrate the case of a 34-year-old female with no previous psychiatric history who contracted COVID-19 and subsequently developed severe symptoms of psychosis. After presenting to the emergency department with one month of worsening mood, auditory hallucinations, intrusive thoughts, and hyperreligiosity, she was admitted to the inpatient psychiatric unit. The patient was treated with multiple antipsychotic medications and was discharged in stable condition with resolution of her auditory hallucinations; however, her delusions, hyperreligiosity, and negative psychotic symptoms persisted, resulting in a second inpatient psychiatric admission eight days after discharge, during which she again did not reach full remission. Objectives With this information, we hope to increase awareness of COVID-induced psychosis and further discuss the relationship between COVID-19 infection and neuropsychiatric symptoms. Conclusions Although there has been increasing research about the COVID-19 pandemic, there is much to be elucidated regarding the neuropsychiatric symptoms related to these infections. Similar to previous studies, our case describes a patient with no previous psychiatric history who developed severe psychotic symptoms after COVID-19 infection and was admitted to the inpatient psychiatric unit. These symptoms resulting from infection can be severe or debilitating for the patient. Therefore, physicians should be aware of these potential neuropsychiatric sequelae when treating patients with active COVID-19 infections, and treatment with antipsychotics or acute inpatient psychiatric admission should be considered.
Large-Scale Turbulence in Molecular Clouds

Principal component analysis of 12CO (J = 1-0) emission is used to diagnose the presence of large-scale, global velocity fluctuations in molecular clouds. We search for, and find, large-scale flows of atomic material in which the globally turbulent molecular clouds are embedded. This is consistent with the picture of molecular clouds existing as short-lived, turbulent density fluctuations within larger scale atomic flows. Large-scale driving of turbulence in molecular clouds, by converging flows of atomic material, can reconcile recent numerical determinations of the dissipation rate of turbulent energy with the observations, that otherwise, for small-scale driving, leads to unacceptably high cloud luminosities. On the other hand, lack of large-scale shock signatures in the molecular gas, as expected for large-scale driving, may, if not due to an observational bias, require that the large-scale flows are themselves driven by energy injection occurring on smaller scales within molecular clouds.
Minimax Problems for Set-Valued Mappings

In this article, by virtue of the Fan-Browder fixed point theorem, we first obtain a minimax theorem and establish an equivalent relationship between the minimax theorem and a cone saddle point theorem for scalar set-valued mappings. Then, by using scalarization functions, we investigate an existence theorem of the cone saddle point for set-valued mappings. Simultaneously, we also establish a minimax theorem for set-valued mappings.
Performance Improvement of Shunt Active Power Filter using Modified Hysteresis Current Controller

: Shunt active power filters (APFs) have emerged as a potential player to address power quality issues imposed by exponentially increasing nonlinear loads.The shunt APF used in this work is essentially a three-phase, three-wire PWM based current controlled voltage source inverter (VSI). Hysteresis current controllers (HCCs) are extensively used for gate pulse generation in converter circuits due to easy implementation and better dynamic response. This work explores the possibility of performance enhancement of shunt APF using a proposed modified HCC based on digital logic. The proposed modified HCC based shunt APF provides significant reduction in switching frequency, switching losses, better mitigation of harmonics and smoother reactive power flow. The dynamic analysis of performance of shunt APF with conventional and modified hysteresis current controller (HCC) is performed under randomly varying non-linear loading conditions. The simulated results confirm the ascendency of the modified HCC scheme over conventional HCC under transient as well as steady state conditions. The modified HCC emerges out to be a better scheme with manifold advantages and enhances the performance of shunt APF tremendously.
In High‐TC Superconductors, is D‐Wave the New Wave?

Theorists trying to explain the mechanism for superconductivity in the copper oxide materials may not agree on much, but they all do believe it involves the coupling of electrons of opposite spin. Paths quickly diverge when it comes to the angular momentum of the pair. Is it a BCS‐like swave (with l = 0)? A d‐wave? Or something else? The answer is linked to the mechanism that couples the electrons. Although early experiments seemed consistent with an swave pairing, recent measurements suggest that the pairing state is at least not isotropic. If the experiments can further delineate the symmetry of the pairing state, they might help narrow the field of contending theories.
Symbolic Covariance Principal Component Analysis and Visualization for Interval-Valued Data

This article proposes a new approach to principal component analysis (PCA) for interval-valued data. Unlike classical observations, which are represented by single points in p-dimensional space ℜp, interval-valued observations are represented by hyper-rectangles in ℜp, and as such, have an internal structure that does not exist in classical observations. As a consequence, statistical methods for classical data must be modified to account for the structure of the hyper-rectangles before they can be applied to interval-valued data. This article extends the classical PCA method to interval-valued data by using the so-called symbolic covariance to determine the principal component (PC) space to reflect the total variation of interval-valued data. The article also provides a new approach to constructing the observations in a PC space for better visualization. This new representation of the observations reflects their true structure in the PC space. Supplementary materials for this article are available online.
A semi-continuous extended kinetic model

A set of semi-continuous model Boltzmann equations governing the evolution of a three-component gas mixture is presented. The third species is treated as an excited state of the second species. The model takes into account collisional excitation and de-excitation processes as well as the interaction with monochromatic photons. A kinetic equation for photons is coupled with the model Boltzmann equations. Conservation properties are established and an H-theorem is proven. Numerical solutions to simple test cases are provided.
Cycle Decompositions and Simulated Annealing

The behavior of simulated annealing algorithms is tightly related to the hierarchical decomposition of their configuration spaces in cycles. In the generalized annealing framework, this decomposition is defined recursively. In this paper, its structure is extensively studied, and it is shown that the decomposition can be achieved through an implementable algorithm which allows exact computation of the fundamental constants underlying the behavior of these algorithms.
Determination of saturated parameters of PM motors using loading magnetic fields

The precise knowledge of parameters is of critical importance for the correct performance prediction and design optimization of permanent magnet (PM) motors. A method for numerical calculation of the saturated direct and quadrature reactances X/sub d/, X/sub q/ and excitation voltage due to magnets E/sub 0/, related to any arbitrary operational case, is proposed. Based on the evaluation of internal voltage from nonlinear load magnetic fields by finite-element method, the parameters X/sub d/, X/sub q/, and E/sub O/ are obtained. The proposed procedure has been applied to analyze a laboratory 25 hp PM motor and determine its saturated parameters. There exists a close agreement between the simulation and experimental results. >
The Implementation of Parallel Speed up Stereo Matching Based on Reduced Graph Cuts

The Many stereo matching problems can be converted to energy minimization problem, by establishment of special network graph to obtain the minimum graph cut, and then obtaining the optimal solution. For graph cuts algorithm, complete network graph include all vertices and disparity edges, the computation of time and space is huge. In this paper, we put forward a method by combing local and global stereo matching, set up a reduced network graph by the possible disparities values for each pixel, and then global optimization, to slove the maximum flow polynomial through CUDA parallel computing, greatly reduced the consumption of time and space.
Vertically integrated silicon-germanium nanowire field-effect transistor

We demonstrate in this paper the possibility to vertically integrate SiGe nanowires in order to use them as vertical channel for field-effect transistors (FETs). We report a threshold voltage close to 3.9 V, an ION/IOFF ratio of 104. The subthreshold slope was estimated to be around 0.9 V/decade and explained by a high traps density at the nanowire core/oxide shell interface with an estimated density of interface traps Dit ∼ 1.2 × 1013 cm−2 eV−1. Comparisons are made with both vertical Si and horizontal SiGe FETs performances.
Commutativity of Pfaffianization and Bäcklund transformations: the KP equation

The Pfaffianization procedure is applied to the modified KP equation. As a result, we derive a coupled modified KP system, which is shown to constitute a bilinear Bäcklund transformation for the coupled KP (cKP) equation introduced by Hirota and Ohta. This means that commutativity of Pfaffianization and Bäcklund transformation is valid for the KP equation. As a by-product, we explicitly derive a coupled system from Bäcklund transformation formulae of the cKP equation, which solves an open problem proposed by Hirota. In addition to starting from the Bäcklund transformation, a Lax pair for the coupled KP equation is worked out. Finally, two kinds of Pfaffian solutions to the coupled modified KP equation are derived.