Miracle-dz/UniFAR-FTUs huggingface dataset:
The 2003 October-November Fast Halo Coronal Mass Ejections and the Large-Scale Magnetic Field Structures

The coronal magnetic field, computed from synoptic maps of the magnetic field and a potential field source surface (PFSS) model, reveals special configurations related to the active regions that were associated with most, if not all, fast halo coronal mass ejections (CMEs) in 2003 October-November. It was shown that these active regions emerged in an open field area, produced a large open field area after emerging, or sat on a boundary of two open field areas with the same polarity. This type of boundary is also known as a "plasma sheet. " Such magnetic structures appear to be favorable for the propagation of the disturbance. MHD simulations were performed here to explore the behavior of the propagation of the disturbance against these special configurations of the background magnetic field. It is demonstrated that without the presence of open flux, the speed of the CMEs would have been only 78% of that with open flux present. It is also found that the CMEs from a heliospheric current sheet have a speed only 67% of the CMEs' speed from a plasma sheet, the source boundary with the same polarity.
Effect of Digestate Modified with Amendments on Soil Health and Plant Biomass under Varying Experimental Durations

A digestate with amendments provides plants with available nutrients and improves the microbiological properties of treated soil. Modification of a digestate through the addition of a biochar and sulphur source is less well-known. This pot experiment aimed at comparing the short- and long-time fertilization effects of a digestate enriched with biochar, with elemental sulphur, or with a combination of both on soil health and plant biomass. The experiment was carried out with maize, cultivated twice (1st–12th week = pre-cultivation; re-sowing after shoot harvest, 13th–24th = main cultivation) in soil amended with prepared digestate. The digestate used in pre-cultivation was incubated untreated (D) and was then treated with biochar (D + B), with elemental sulphur at a low (LS) and high (HS) dose, or with a combination of both (D + B + LS and D + B + HS). An additional unamended digestate (D) was added to each soil variant before the main cultivation. The application of digestate with a high dose of elemental sulphur and biochar mediated the most significant differences in the soil. The increase (compared to the unamended soil) was of short-term type (+11% and +6% increased total nitrogen and carbon after 12 weeks), then of long-term type (+54% and +30% increased sulphur and arylsulfatase activity after 24 weeks), and later emerged in the 13th to the 24th week of the experiment (+57% and +32% non-inhibited urease, increased N-acetyl-β-D-glucosaminidase and phosphatase). No significant differences in the effect of the applied amendments on dry aboveground plant biomass were observed.
Self-propulsion in a viscous fluid: arbitrary surface deformations

The self-propulsion of a generally deformable body at low-Reynolds-number conditions is discussed. The translational and rotational velocities of the body relative to an inertial reference system are presented as surface quadratures using a Lagrangian ‘body-fixed’ shape description. The power dissipated into the fluid is obtained as a quadratic functional of the surface deformation rate. For symmetric strokes, the net displacement obtained by the execution of a single deformation cycle is provided by a functional of the intrinsic swimmer shape and its time derivative.
An explicit determination of the empty space-times on which the wave equation satisfies Huygens' principle

Abstract The validity of Huygens' principle in the sense of Hadamard's ‘minor premise’ is investigated for scalar wave equations on curved space-time. A new necessary condition for its validity in empty space-time is derived from Hadamard's necessary and sufficient condition using a covariant Taylor expansion in normal coordinates. A two component spinor calculus is then employed to show that this necessary condition implies that the plane wave space-times and Minkowski space are the only empty space-times on which the scalar wave equation satisfies Huygens' principle.
Complex Paraconformal Manifolds – their Differential Geometry and Twistor Theory

A complex paraconformal manifold is a/^-dimensional complex manifold (/? , q > 2) whose tangent bündle factors äs a tensor product of two bundles of ranks p and q. We also assume that we are given a fixed isomorphism of the highest exterior powers of the two bundles. Examples of such manifolds include 4-dimensional conformal manifolds (with spin structure) and complexified quaternionic, quaternionic Kahler and hyperKähler manifolds. We develop the differential geomety of these structures, which is formally very similar to that of the special case of four dimensional conformal structures [30]. The examples have the property that they have a rieh twistor theory, which we discuss in a unified way in the paraconformal category. In particular, we consider the 'non-linear graviton' construction [29], and discuss the structure on the twistor space corresponding to quaternionic Kahler and hyperKähler metrics. We also define a family of special curves for these structures which in the 4-dimensional conformal case coincide with the conformal circles [34,2]. These curves have an intrinsic, naturally defined projective structure. In the particular case of complexified 4Ä>dimensional quaternionic structures, we obtain a distinguished 8fc + l parameter family of special curves saüsfying a third order ODE in local coordinates. 1980 Mathematics Subject Classification (1985 Revision): 53A30; 32L25, 58G30.
Non-parametric and semi-parametric estimation of spatial covariance function

I will present three projects that are related to the modeling of covariance structures on the Euclidean space and on sphere. Firstly, we propose a method to model isotropic random field on sphere, where a tapered Matern covariance function is used to capture the local behavior while a nonparametric expansion controls the behavior at large distances. A model selection procedure based on residual sum of squares with penalization is used to reduce over fitting. Secondly, we address the issue of modeling axially symmetric spatial random fields on sphere with a kernel convolution approach. The observed random field is generated by convolving a latent uncorrelated random field with a class of Matern type kernel functions. By allowing the parameters in the kernel functions to vary with locations, we are able to generate a flexible class of covariance functions and capture the nonstationary properties. We use pre-computation tables to speed up the computation. For regular grid data on sphere, the block circulant property of the covariance matrix enables us to use Fast Fourier Transform (FFT) to get the determinant and the inverse efficiently. Thirdly, we proposed a semiparametric variogram estimating method through its spectral representation to model the intrinsically stationary random on R. The low frequency part of the spectral density is estimated by solving a regularized inverse problem through quadratic programming. The behavior at high frequencies, however, is modeled via a parametric tail in the form of a power decaying function. The power parameter in the tail is estimated by a log likelihood method. All proposed methodologies are supplemented with simulation studies and real data analyses.
Spatial Frequency Tuning of Body Inversion Effects

Body inversion effects (BIEs) reflect the deployment of the configural processing of body stimuli. BIE modulates the activity of body-selective areas within both the dorsal and the ventral streams, which are tuned to low (LSF) or high spatial frequencies (HSF), respectively. The specific contribution of different bands to the configural processing of bodies along gender and posture dimensions, however, is still unclear. Seventy-two participants performed a delayed matching-to-sample paradigm in which upright and inverted bodies, differing for gender or posture, could be presented in their original intact form or in the LSF- or HSF-filtered version. In the gender discrimination task, participants’ performance was enhanced by the presentation of HSF images. Conversely, for the posture discrimination task, a better performance was shown for either HSF or LSF images. Importantly, comparing the amount of BIE across spatial-frequency conditions, we found greater BIEs for HSF than LSF images in both tasks, indicating that configural body processing may be better supported by HSF information, which will bias processing in the ventral stream areas. Finally, the exploitation of HSF information for the configural processing of body postures was lower in individuals with higher autistic traits, likely reflecting a stronger reliance on the local processing of body-part details.
Chemical Properties of Aircraft Engine Particulate Exhaust Emissions

The chemical properties of the particulate exhaust emissions from an in-use commercial aircraft engine were characterized in April 2004 as part of the Aircraft Particle Emissions Experiment. The test aircraft was the NASA DC-8 equipped with CFM56-2-C1 engines and the test matrix included 11 different engine throttle levels, three fuel compositions, and three sampling distances. The variations in particle emissions number, size, mass, and chemical composition were measured using a suite of instruments, including an aerosol mass spectrometer. The particle emissions were characterized by a trimodal size distribution. The largest mode was dominated by ambient accumulation mode particles mixed into the plume. The middle mode consisted of carbon soot with sulfate and organic coatings. The smallest mode was completely volatile and consisted of sulfate and organic components. The soot emission indices increased with power from 2―120 mg/kg fuel. The semivolatile components increased with distance and decreased with power from 33―5 mg/kg fuel. The sulfate emissions increased with distance and fuel sulfur content. The emissions under low power were dominated by organics, and the high-power conditions were dominated by soot. The CFM56 engine was less efficient at the low thrust levels typically used on the ground at an airport.
Efficacy of Transcutaneous Tibial Nerve Stimulation With Silver Spike Point® Electrodes for Refractory Overactive Bladder: A Single-Arm Study

Background Tibial nerve stimulation therapy is a treatment option for an overactive bladder. A surface electrode called a Silver Spike Point® electrode, which does not directly puncture the skin as in transcutaneous tibial nerve stimulation, but is expected to exert the same therapeutic effect as percutaneous tibial nerve stimulation, was developed. This study investigated the efficacy and safety of tibial nerve stimulation with Silver Spike Point® electrodes for refractory overactive bladder. Methodology This was a six-week, single-arm, prospective study on the efficacy and safety of transcutaneous tibial nerve stimulation for patients with refractory overactive bladder. Each treatment lasted 30 minutes and was performed twice a week. The stimulation sites of the tibial nerve were the Sanyinjiao point (SP6) and Zhaohai point (KI6) in both legs. The primary endpoint was the change in the total overactive bladder symptom score. Results In total, 29 patients (20 males and nine females: 64.86 ± 17.98 years old) were included in this study. Two women dropped out; one because of an adverse event and the other as requested. Therefore, 27 patients completed the study. The total overactive bladder symptom and International Consultation on Incontinence Questionnaire-Short Form scores significantly decreased by 2.22 and 2.39 points, respectively (p < 0.01 each). In the frequency volume chart, the numbers of urgency episodes and leaks in 24 hours significantly decreased by 1.53 and 0.44, respectively (p = 0.02 each). Conclusions Transcutaneous tibial nerve stimulation therapy using Silver Spike Point® electrodes was useful for patients with refractory overactive bladder and, thus, has potential as a new treatment option for refractory overactive bladder.
Laboratory Study of Unidirectional Focusing Waves in Intermediate Depth Water

The results of laboratory measurements of large focusing wave groups, which were generated using the New Wave theory, are presented. The influences of both the steepness and frequency bandwidth on focused wave characteristics were examined. The influence of frequency bandwidth on focused wave groups with small and moderate steepness was very small. However, for cases with the large steepness, the nonlinearity increased with increasing bandwidth frequency and widened free-wave regimes are identified for those cases with large steepness at the focal location. The underlying nonlinear phase coupling of focused waves was examined using wavelet-based bicoherence and biphase, which can detect nonlinear phase coupling in a short time series. For wave groups with large initial steepness, as wave groups approached the focal location, the values of bicoherence between primary waves and its higher harmonics progressively increased to 1 and the corresponding biphase was gradually close to zero, suggesting that an extreme wave event can be produced by considering Stokes-like nonlinearity to very high-order. Furthermore, the fast change of bicoherence of focused wave groups indicates that the nonlinear energy transfer within focusing waves is faster than that of nonfocusing wave trains.
Hybrid Foil-Litz Windings for Highly Efficient and Compact Medium-Frequency Transformers

Medium-frequency transformers (MFTs) are key components in solid-state transformers, where they provide galvanic isolation and a certain voltage transfer ratio between a MV grid and a LV bus. Typically, MFTs are operated in the kilohertz range, which results in a significantly reduced volume and material usage compared to 50/60 Hz transformers. Foil conductor is an attractive solution for improving the filling factor and the cost-effectiveness of MFTs, however, the insulation clearances increase the ohmic losses due to the current crowding effect; besides, the electric field hotspots at the winding corners require shielding by equipotential rings. In this work, a new hybrid topology is presented, where the first and last turn of the foil winding package is replaced by turns of litz wire connected in series, one above and one below the foil winding, respectively, such that they act as equipotential shielding rings; besides, the current in the litz turns deflects the magnetic field lines away from the foil edges, decreasing the losses due to current crowding. The effect of the litz rings on the losses is modeled and measured on a hybrid and a standard foil winding prototype; a loss decrease higher than 15% is observed. The verified model is used to compare the conductor and footprint saving between windings designed with litz rings, and with standard equipotential shielding rings; in this respect, a minor amount of litz wire allows reducing losses up to 30%, whereas the conductor utilization and winding height can be decreased more than 20%, improving the power density of the MFT.
Register variation, truncation, and subject omission in English and in French

This paper concerns the null subject phenomenon attested in abbreviated written registers in English and in French (diaries, instructions) and in informal spoken English. Neither a pro drop analysis nor a topic drop analysis will account for the incompatibility of the English null subjects with wh-preposing and with embedded contexts. Rizzi's (1994) analysis for null subjects in child production is adopted here in a slightly modified form. Like the early null subject, the (adult) null subject in abbreviated registers is an antecedentless empty category in the A-specifier of the root. Null subjects depend on the truncation of CP, which turns the specifier of IP into the highest specifier of the clause. The paper explores apparent noninitial null subjects, i.e. null subjects co-occurring with preposed adjuncts (though not arguments) and shows that these can be accounted for in terms of partial truncation within an articulated CP. The null subject is an antecedentless empty category in the (A-)specifier of an AGR-projection dominating the Topic Projection. The incompatibility with wh-preposing and with argument preposing is accounted for. In a more speculative vein I also consider the deletion of be in the abbreviated styles, which I claim can also be analysed in terms of truncation.
Three lectures on local cohomology modules supported on monomial ideals

These notes are an extended version of a set of lectures given at ”MONICA: MONomial Ideals, Computations and Applications”, at the CIEM, Castro Urdiales (Cantabria, Spain) in July 2011. The goal of these lectures is to give an overview of some results that have been developed in recent years about the structure of local cohomology modules supported on a monomial ideal. We will highlight the interplay of multi-graded commutative algebra, combinatorics and D-modules theory that allow us to give different points of view to this subject. We will try to preserve the informal character of the lectures, so very few complete proofs are included
On multiphase turbulence models for collisional fluid–particle flows

Abstract Starting from a kinetic theory (KT) model for monodisperse granular flow, the exact Reynolds-averaged (RA) equations are derived for the particle phase in a collisional fluid–particle flow. The corresponding equations for a constant-density fluid phase are derived from a model that includes drag and buoyancy coupling with the particle phase. The fully coupled macroscale/hydrodynamic model, rigorously derived from a kinetic equation for the particles, is written in terms of the particle-phase volume fraction, the particle-phase velocity and the granular temperature (or total granular energy). As derived from the hydrodynamic model, the RA turbulence model solves for the RA particle-phase volume fraction, the phase-averaged (PA) particle-phase velocity, the PA granular temperature and the PA turbulent kinetic energy of the particle phase. Thus, unlike in most previous derivations of macroscale turbulence models for moderately dense granular flows, a clear distinction is made between the PA granular temperature $\Theta _\textit {p}$ , which appears in the KT constitutive relations, and the particle-phase turbulent kinetic energy $k_\textit {p}$ , which appears in the turbulent transport coefficients. The exact RA equations contain unclosed terms due to nonlinearities in the hydrodynamic model and we briefly discuss the available closures for these terms. Finally, we demonstrate by comparing model predictions with direct numerical simulation results that even for non-collisional fluid–particle flows it is necessary to provide separate models for $\Theta _\textit {p}$ and $k_\textit {p}$ in order to correctly account for the effect of the particle Stokes number and mass loading.
Geometry and Prediction of Drift-Free Trajectories for Redundant Machines Under Pseudoinverse Control

In this article, classical differential geometric techniques are used for two purposes: (1) to describe in geometric terms the trajectories to which redundant robots under pseudoinverse control will drift and (2) to formulate from this geometric description a practical and quick method for predicting these limit trajectories, thereby suggesting sets of initial conditions under which no drift will occur. Through this analysis, several useful results were obtained. First, it is demonstrated for a 3R example that the drifting trajectories are geodesics in the constrained joint space, and that as a result of this, all drift-free tra jectories are space curves of zero torsion. Second, it is found that each self-motion manifold in the joint space crosses the limiting (drift-free) trajectories at points where they themselves have zero torsion. Because self-motion manifolds are often more easily computed than exhaustive kinematic simulation of manipulator drift, these results provide a fast, new technique for locating and character izing drift-free trajectories based only on geometry of these self-motion manifolds. This work extends the results of previous work in pseudoinverse control to the point that the drift problem may be circumvented without resort to either exhaustive simulation or symbolic computation of Lie brackets of vector fields.
Plane Waves in a Thermoelastic Solid

In an isotropic, thermoelastic solid shear waves are unaltered by thermal effects. However, two distinct dilatational waves exist, both of which are dispersed and attenuated by the medium. One of the waves (denoted the Ewave) is close in character to the pure elastic wave, the other wave (denoted the Twave) is similar in nature to the pure thermal wave. The properties of the two dilatational motions are studied and relations are given expressing the variation, in each, of phase velocity, amplitude attenuation, and specific loss with impressed frequency. For the Ewave the result is verified that this disturbance propagates at the adiabatic velocity at low frequencies and at the isothermal velocity at very high frequencies. An explanation based on physical considerations is offered to account for this generally overlooked phenomenon. It is further found that the amplitude is attenuated exponentially as the square of the frequency at relatively low frequencies, but approaches finite value as the frequency increases without limit. The specific loss reaches maximum for the E wave, a minimum for the Twave, near the frequency whose period is equal to the relaxation time due to thermal currents. Finally, the ratios are computed of the amplitude of the temperature to the amplitude of the displacement in each of the two modes of motion. Numerical work indicates that, for metals at room temperature, the effect of coupling between elastic and thermal motions is very small.