Miracle-dz/UniFAR-FTUs huggingface dataset:
The implications of the pandemic for the corporate governance, remuneration and sustainability performance of South African listed companies

The study examined the implications of the recent pandemic on the corporate governance, remuneration and corporate sustainability performance of South African listed companies. Data from 42 companies was analyzed using the panel fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) methods from 2010-2021. Findings revealed that the pandemic negatively impacted the selected companies. This study revealed that the pandemic had a good impact on some companies and not just bad ones as claimed by previous researchers. Results from COVID -19- related expenses, debt-to-equity ratios and staff costs revealed a negative but significant result in the estimated model. Other variables such as current ratios, net profit margins and board diversity revealed a positive and significant relationship with all the dependent variables. Hence, a very severe implication of the pandemic on the performance of companies is confirmed through COVID -19related expenses, staff costs and directors’ remuneration. These have a very strong negative impact on the future performance, survival, and sustainability of the selected companies. Lastly, a strong relationship between corporate governance and corporate sustainability performance was confirmed as shown by ROA, board size, directors’ remunerations and board diversity. This study provides insight for stakeholders such as governments, directors and policymakers to develop both preventive and proactive policies to protect and guide companies from future similar pandemics. To avert and prevent future negative implications on companies, this study recommends a well- structured scheme for all of the company’s staff, cash reserves and IT governance.
Conduction Behavior of V-SrZrO3 Thin Film Showing Resistive Switching

This paper examines the electrical properties of V-doped SrZrO3 sputtered films showing bistable on/off resistive switching. The temperature dependence of dc sweep I-V data in the range of 25–100°C implies the prominent role played by the off-state conduction in determining the R-switch ratio. The defects in off-state are investigated via Frenkel-Poole relation and the associated trap energy extraction. It is found that the oxygen vacancies are the possible major defects in off-state and are verified by the treatment of N2 and O2 annealing ambience hereafter. The nearly unchanged currents suggest the relatively more stable nature in on-state, which is consistent with the following findings: 1) the frequently observed I-V jiggle during on to off switching, 2) successful forming only found for sweep direction to on-state, 3) the better thermal disturbance immunity by longer retention for on-state, 4) the shorter pulse width needed to on-state switching for electric pulse induced resistance (EPIR) effect.
Zone‐melting recrystallization with enhanced radiative heating for preparation of subboundary‐free silicon‐on‐insulator thin films

A new zone‐melting‐recrystallization (ZMR) configuration with enhanced radiative heating has been developed for preparing silicon‐on‐insulator (SOI) films. With this configuration, in which the sample is positioned above the movable heater with the SOI film facing downward, subboundary‐free 0.5‐μm‐thick SOI films are obtained over a much wider range of experimental parameters than with the conventional ZMR configuration. The characterization of these films by defect etching, optical microscopy, and transmission electron microscopy shows that the principal defects are isolated threading dislocations with a density of ∼106 cm−2. It should be possible to improve the material quality still further by optimizing experimental conditions for the new configuration.
Neutron starquake models for gamma-ray bursts

We assess neutron starquake models for γ-ray bursts. The elastic energy the crust can store is sufficient to account for that radiated in a single burst, but it is insufficient to supply the ≳ 10^6 bursts each star produces over its lifetime, and so it must be replenished. Seismic waves are radiated if shear stress is relieved by brittle fracture. However they cannot propagate directly to the surface but are temporarily trapped below a reflecting layer. Between the reflecting layer and the surface the displacement amplitude of the wave is nearly constant and the strain is very small. At low frequencies, ≾ 10^4 Hz, the reflection is associated with an evanescent zone. At high frequencies, ≳ 10^4 Hz, the reflection occurs where the magnetic field stress starts to dominate the crustal rigidity. The shaking of the stellar surface couples the seismic waves to Alfen waves which propagate out into the magnetosphere. At low frequencies, the coupling coefficient, T, is proportional to the square of the magnetic field, B, and increases with the seventh power of the wave frequency, v. At high frequencies, T is proportional to B^(4/7)v^(3/7). Alfven wave luminosities sufficient to power Galactic γ-ray bursts are possible if magnetic fields ≳ 10^(11) G cover at least part of the stellar surface. The conversion of Alfven waves into γ-rays may occur if the waves are charge-starved or if their amplitudes approach that of the background magnetic field.
Hydraulic properties of two‐dimensional random fracture networks following a power law length distribution: 2. Permeability of networks based on lognormal distribution of apertures

The broad length and aperture distributions are two characteristics of the heterogeneity of fractured media that make difficult, and even theoretically irrelevant, the application of homogenization techniques. We propose a numerical and theoretical study of the consequences of these two properties on the permeability of bidimensional synthetic fracture networks. We use a power law for the model of length distribution and a lognormal model for aperture distribution. We have especially studied the two endmost models for which length and aperture are (1) independent and (2) perfectly positively correlated. For the model without correlation between length and aperture we show that the permeability can be adequately characterized by a power‐averaging function whose parameters are detailed in the text. In contrast, for the model with correlation we show that the prevailing parameter is the correlation when the power law length exponent a is lower than 3, whereas the random structure of the network is a second‐order parameter. We also determine the permeability scaling and the scale dependence of the flow pattern structure. Three types of scale effects are found, depending exclusively on the geometrical properties of the network, i.e., on the length distribution parameter a. For a larger than 3, permeability decreases for scales below a definite correlation length and becomes constant above. We show in this case that a correlation between length and aperture does not fundamentally change the permeability model. In all other cases the correlation entails much larger‐scale effects. For a in the range 1–;3 in the case of an absence of correlation and for a in the range 2–3 in the case of correlation, permeability increases and tends to a limit, whereas the flow structure is channeled when permeability increases and tends to homogenize when permeability tends to its limit. We note that this permeability model is consistent with natural observations of permeability scaling. For a in the range 1–2, in the case of correlation, permeability increases with scale with no apparent limit. We characterize the channeled flow pattern, and we show that permeability may increase even when flow is distributed in several independent structures.
Control of multistability in a directly modulated diode laser

A semiconductor laser with modulated injection current has the property that many competing behaviors are possible and the system tends to alternate among them. Such a situation is not desirable if a stable output is required. We show with numerical simulations that additional slow harmonic modulation can annihilate undesirable coexisting attractors in this laser. We demonstrate great flexibility of the method in manipulating the laser's dynamics to select a desired behavior and even to make the system monos table.
Summary Wetested the hypothesis thatthe increased incidence of schizophrenia among Surinamese immigrants toThe Netherlands could be explainedbya similarlyhigh incidence in Surinam.We conducted a1-year first- contact incidence

thatthe increased incidence of schizophrenia among Surinamese immigrants toThe Netherlands could be explainedbya similarlyhigh incidence in Surinam.We conducted a1-year firstcontact incidence studyin Surinamand compared the findingswith data froma similar studyconducted inThe Netherlands using the same inclusion criteria and instruments . The riskof developinga schizophrenic disorderwas 2.4 timeshigher (95% CI1.3^4.2) in Surinamese immigrants than inresidents of Surinam.The increasedrisk is probably due to environmental factors inThe Netherlands.
DISCRETE SERIES FOR THE UNIVERSAL COVERING GROUP OF THE 3 + 2 DE SITTER GROUP.

A classification is given of the irreducible unitary representations of the universal covering group of the 3 + 2 de Sitter group which contract to the usual physical representations of the Poincare group. These representations include the discrete series for the 3 + 2 de Sitter group. The classification problem is reduced from one for the group to the corresponding one for the Lie algebra. The method used by Thomas for the representations of the 4 + 1 de Sitter group is then followed, except that a representation is reduced out with respect to the irreducible unitary representations of a noncompact 2 + 2 subalgebra. It is conjectured that each representation of this subalgebra occurs at most once. The action on the representation spaces of a basis for the Lie algebra is given. The contractions of the representations to those of the Poincare, oscillator and the Galilei groups are briefly considered.
Cramér–Rao Lower Bound Analysis of Differential Signal Strength Fingerprinting for Crowdsourced IoT Localization

Crowdsourcing is considered an efficient and promising paradigm for constructing large-scale signal fingerprint radio maps due to the proliferation of Wi-Fi-enabled devices. However, a crowdsourced indoor positioning system (IPS) has to handle diverse devices and the inherent heterogeneity in received signal strength (RSS) measurements. To address the device heterogeneity problem, differential fingerprinting methods have been explored, which mitigate the device characteristics that cause RSS from different commercial devices to report differently. In this article, we focus on mean differential fingerprinting (MDF) that produces the differential fingerprints by subtracting the mean RSS value of all access points from the original RSS fingerprints. We study the localization performance of the MDF method by means of the Cramér–Rao lower bound (CRLB) and show analytically that it outperforms another method that addresses device diversity. Furthermore, we evaluate the localization accuracy of existing solutions using real-life Wi-Fi RSS data sets collected by multiple consumer devices. The experimental results confirm our analytical findings and demonstrate the effectiveness of the MDF method to mitigate device diversity, as well as other factors that affect the RSS readings, including the device carrying mode and power control schemes of the Wi-Fi infrastructure, thus contributing to the wider adoption of crowdsourced IPS.
The hydrogen molecule and the H+2 molecular ion inside padded prolate spheroidal cavities with arbitrary nuclear positions

A generalization of previous theoretical studies of molecular confinement based on the molecule-in-a-box model for the H+2 and H2 systems whereby the confining cavity is assumed to be prolate spheroidal in shape is presented. A finite height for the confining barrier potential is introduced and the independent variation of the nuclear positions from the cavity size and shape is allowed. Within this scheme, the non-separable Schrödinger problem for the confined H+2 and H2 molecules in their ground states is treated variationally. In both cases, an important dependence of the equilibrium bond length and total energy on the confining barrier height is observed for fixed cavity sizes and shapes. It is also shown that—given a barrier height—as the cavity size is reduced, the limit of stability of the confined molecule is attained for a critical size. The results of this work suggest the adequacy of the proposed method for more realistic studies of electronic and vibrational properties of confined one- and two-electron diatomics for proper comparison with experiment.
Natural Convection Heat Transfer Enhancement in a Square Cavity Periodically Cooled from Above

The present article reports numerical results of natural convection within an air filled square cavity with its horizontal walls submitted to different heating models. The temperature of the bottom horizontal surface (hot temperature) is maintained constant, while that of the opposite surface (cold temperature) is varied sinusoidally with time. The remaining vertical walls are considered adiabatic. The parameters governing the problem are the amplitude (0 ≤ a ≤ 0.8) and the period (τ ≥ 0.001) of the variable temperature, the Rayleigh number (103 ≤ Ra ≤ 7 × 106), and the Prandtl number (Pr = 0.71). In constant cooling conditions (a = 0), up to three different solutions (monocellular flow MF, bicellular vertical flow BVF, and bicellular horizontal flow BHF) are obtained. Their existence ranges are delineated and, in the limits of the existence range of each solution, the transitions observed are identified and described. In the variable cooling conditions, the effect of the amplitude and the period of the exciting temperature on fluid flow and heat transfer is examined in the case of the MF, and BHF for specific values of Ra. Results are presented in terms of Ψ max (t), Ψ min (t), Nu(t) and streamlines, heatlines, and isotherms during the evolutions of selected flow cycles. In comparison with the constant heating conditions, it is found that the variable cooling temperature could lead to a drastic change in the flow structure and the corresponding heat transfer, especially at specific low periods of the cold variable temperature. This leads to a resonance phenomenon characterized by an important increase in heat transfer by about 46.1% compared to the case of a constant cold temperature boundary condition.
Abundance and composition of floating microplastics in the central-western Mediterranean Sea

74 neuston samples were collected during two consecutive cruises carried out in the Mediterranean Sea between May and June 2013 (Fig. 1). Samples were all collected using a 200 μm Neuston net which was towed for ~ 5 minutes at a speed of 1.5-2 knots. Samples were fixed with 80% EtOH and stored for laboratory analysis. A mechanical flowmeter was used to measure the trawl length. In the laboratory, samples were sorted at the stereomicroscope. All plastic particles were hand-picked using laboratory tweezers and separated into seven size classes by sequential sieving through a series of stacked stainless steel meshes. All particles in each size category were counted, dried, weighed on an electronic balance and classified according to 5 shape and 7 colour categories. Because of the high risk of air-borne contamination, all synthetic fibres were subsequently excluded from density calculations.
Stability for the inverse resonance problem for a Jacobi operator with complex potential

The potential of a discrete half-line Schrödinger operator is uniquely determined by the location of its Dirichlet eigenvalues and resonances. In a practical setting one can expect only to know a finite number of these. In this paper we give an estimate for the difference of two potentials (one of them finitely supported) for which eigenvalues and small resonances are the same but which may differ with respect to their large resonances.
Can government expenditure help reconstruct the Syrian economy in the post-conflict period? evidence from the SVAR and nonlinear ARDL models

ABSTRACT This paper explores the viability of the fiscal policy in the reconstruction of the Syrian economy. We use the Structural VAR estimation technique to assess the response of real GDP to shocks in government expenditures and exchange rates in the parallel market. We also control for other variables including money supply and oil prices. We find that government spending is an effective tool for economic recovery in particular under a quasi-fixed exchange rate regime. We also employ the nonlinear ARDL (NARDL) model to detect the existence of asymmetrical effects of government spending on real GDP. The NARDL results show that negative changes in government expenditure have more impact on economic growth compared to positive changes. Additionally, the NARDL model reveals that the post-conflict period was characterized by large government spending’ inefficiencies. Finally, we study three alternative government spending’ rebuilding scenarios. We document that reaching the pre-conflict GDP level is possible under two of the scenarios we investigate. Hence, our results provide strong policy implications according to which fiscal policy can, under specific exchange rate regimes, reverse the adverse effects of civil wars.
Terrestrial foreshock Langmuir waves: STEREO observations, theoretical modeling, and quasi‐linear simulations

[1] Langmuir waves in the terrestrial electron foreshock are investigated using observations from the STEREO spacecraft, theoretical modeling, and quasi-linear simulations. Emphases are placed on spatial variations of Langmuir field strength with distance between the spacecraft and the tangent point and on the effects of ambient density fluctuations on these variations. The STEREO mission provides new observations of foreshock Langmuir waves at distances more than twice as far from Earth as previously observed. Based on established geometric properties of the foreshock region, two methods are developed for separating Langmuir waves of foreshock origin from those of solar and/or heliospheric origins. The observed maximum foreshock Langmuir field strength falls with distance via a power law with an exponent −1.01 ± 0.12. The theory and simulations predict field strengths and power law spatial variations in field strengths that are consistent with the observations when scattering of Langmuir waves by density fluctuations is included. The power law exponents predicted by both theory and simulations fall within the uncertainty of the observations for the typical solar wind conditions observed but differ by a factor of ≈1.5 from simulations that assume density homogeneity. This indicates that density fluctuations play an important role in the beam-Langmuir wave dynamics in the foreshock.
Dynamical Friction from Fluctuations in Stellar Dynamical Systems

A test particle traveling through a collisionless gravitating background suffers a dissipative drag force known as dynamical friction. As with other dissipative forces, this friction must be related to fluctuations in the underlying medium (fluctuation-dissipation theorem). A theory of the interaction of the test particle with the stochastic force of the background is developed. The Chandrasekhar formula for the friction and the heating of the particle by background fluctuation is derived in a unified way
Fabrication of polymer light‐emitting diodes using doped silicon electrodes

We report the fabrication of light‐emitting diodes from the semiconducting conjugated polymer poly[2‐methoxy,5‐(2’‐ethyl‐hexyloxy)‐1,4‐phenylene‐vinylene], using doped silicon (both n and p type) as an electrode material. Light emission at low voltages is clearly demonstrated. The presence of a thin SiO2 layer at the silicon interface modifies the device characteristics compared to devices fabricated on indium‐tin‐oxide substrates. An interesting consequence of this is the ability to align the Fermi level of the silicon electrode with the lowest unoccupied molecular orbital of the polymer allowing hole injection in forward bias and electron injection in reverse bias.
Elastic behavior of nanoparticle chain aggregates

Nanoparticle chain aggregates (NCA) possess elastomeric properties including stretch under tension, and contraction when the tension is relaxed. Individual chain aggregates of 7 nm titania particles a few hundred nm long were observed in the electron microscope. The NCA were stretched across expanding holes in the carbon film on an electron micrograph grid. After stretching up to 90%, the NCA broke loose at one end and contracted to a tightly folded chain. This pattern was observed in repeated tests. Mechanisms for this behavior and reasons for its generality are proposed. Implications are discussed for the ductility of nanoparticle ceramics, and the increased tensile strength and elastic modulus of rubber due to nanoparticle additives.
An Approach to Traumatic Brain Injury-Related Hypopituitarism: Overcoming the Pediatric Challenges

Traumatic brain injury (TBI)-related hypopituitarism is a rare polymorphic complication of brain injury, with very little data, particularly concerning children and teenagers. This is a comprehensive review of the literature regarding this pathology, starting from a new pediatric case. The research was conducted on PubMed and included publications from the last 22 years. We identified nine original studies on the pediatric population (two case reports and seven studies; only four of these seven were prospective studies). TBI-related hypopituitarism is associated with isolated hormonal deficits ranging from 22.5% to 86% and multiple hormonal deficiencies from 5.9% to 50% in the studied pediatric population. Growth hormone (GH) deficiency is most often found, including the form with late occurrence after TBI; it was described as persistent in half of the studies. Thyroid-stimulating hormone (TSH) deficiency is identified as a distant complication following TBI; in all three studies, we identified this complication was found to be permanent. Adrenocorticotropic hormone (ACTH) deficiency did not relate to a certain type of brain trauma, and it was transient in reported cases. Hyperprolactinemia was the most frequent hormonal finding, also occurring late after injury. Central diabetes insipidus was encountered early post-TBI, typically with a transient pattern and did not relate to a particular type of injury. TBI-related hypopituitarism, although rare in children, should be taken into consideration even after a long time since the trauma. A multidisciplinary approach is needed if the patient is to safely overcome any acute condition.
Completeness, supervenience and ontology

In 1935, Einstein, Podolsky and Rosen raised the issue of the completeness of the quantum description of a physical system. What they had in mind is whether or not the quantum description is informationally complete, in that all physical features of a system can be recovered from it. In a collapse theory such as the theory of Ghirardi, Rimini and Weber, the quantum wavefunction is informationally complete, and this has often been taken to suggest that according to that theory the wavefunction is all there is. If we distinguish the ontological completeness of a description from its informational completeness, we can see that the best interpretations of the GRW theory must postulate more physical ontology than just the wavefunction.